25,400 results on '"Cell size"'
Search Results
2. The effects of high-pressure annealing on magnetostructural transitions and magnetoresponsive properties in stoichiometric MnCoGe.
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Poudel Chhetri, Tej, Chen, Jing-Han, Young, David P., Dubenko, Igor, Talapatra, Saikat, Ali, Naushad, and Stadler, Shane
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MAGNETOCALORIC effects , *TRANSITION temperature , *MAGNETIC entropy , *MAGNETIC transitions , *PHASE transitions , *CELL size , *X-ray diffraction - Abstract
In this study, phase transitions (structural and magnetic) and associated magnetocaloric properties of stoichiometric MnCoGe have been investigated as a function of annealing pressure. Metastable phases were generated by annealing at 800 ° C followed by rapid cooling under pressures up to 6.0 GPa. The x-ray diffraction results reveal that the crystal cell volume of the metastable phases continuously decreases with increasing thermal processing pressure, leading to a decrease in the structural transition temperature. The magnetic and structural transitions merge and form a first-order magnetostructural transition between the ferromagnetic orthorhombic and paramagnetic hexagonal phases over a broad temperature range (>80 K) spanning room temperature, yielding considerable magnetic entropy changes. These findings demonstrate the utility of thermal processing under high pressure, i.e., high-pressure annealing, to control the magnetostructural transitions and associated magnetocaloric properties of MnCoGe without altering its chemical composition. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Eliminating finite-size effects on the calculation of x-ray scattering from molecular dynamics simulations.
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Dohn, A. O., Markmann, V., Nimmrich, A., Haldrup, K., Møller, K. B., and Nielsen, M. M.
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MOLECULAR dynamics , *SOLVATION , *RADIAL distribution function , *TRANSITION metal complexes , *STRUCTURAL reliability , *CELL size , *X-ray scattering , *RENORMALIZATION (Physics) - Abstract
Structural studies using x-ray scattering methods for investigating molecules in solution are shifting focus toward describing the role and effects of the surrounding solvent. However, forward models based on molecular dynamics (MD) simulations to simulate structure factors and x-ray scattering from interatomic distributions such as radial distribution functions (RDFs) face limitations imposed by simulations, particularly at low values of the scattering vector q. In this work, we show how the value of the structure factor at q = 0 calculated from RDFs sampled from finite MD simulations is effectively dependent on the size of the simulation cell. To eliminate this error, we derive a new scheme to renormalize the sampled RDFs based on a model of the excluded volume of the particle-pairs they were sampled from, to emulate sampling from an infinite system. We compare this new correction method to two previous RDF-correction methods, developed for Kirkwood–Buff theory applications. We present a quantitative test to assess the reliability of the simulated low-q scattering signal and show that our RDF-correction successfully recovers the correct q = 0 limit for neat water. We investigate the effect of MD-sampling time on the RDF-corrections, before advancing to a molecular example system, comprised of a transition metal complex solvated in a series of water cells with varying densities. We show that our correction recovers the correct q = 0 behavior for all densities. Furthermore, we employ a simple continuum scattering model to dissect the total scattering signal from the solvent–solvent structural correlations in a solute–solvent model system to find two distinct contributions: a non-local density-contribution from the finite, fixed cell size in NVT simulations, and a local contribution from the solvent shell. We show how the second contribution can be approximated without also including the finite-size contribution. Finally, we provide a "best-practices"-checklist for experimentalists planning to incorporate explicit solvation MD simulations in future work, offering guidance for improving the accuracy and reliability of structural studies using x-ray scattering methods in solution. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Three-dimensional inertial focusing based impedance cytometer enabling high-accuracy characterization of electrical properties of tumor cells.
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Chen Ni, Mingqi Yang, Shuai Yang, Zhixian Zhu, Yao Chen, Lin Jiang, and Nan Xiang
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MACHINE learning , *CELL size , *ELECTRODES , *FLUIDS , *SIGNALS & signaling - Abstract
The differences in the cross-sectional positions of cells in the detection area have a severe negative impact on achieving accurate characterization of the impedance spectra of cells. Herein, we proposed a threedimensional (3D) inertial focusing based impedance cytometer integrating sheath fluid compression and inertial focusing for the high-accuracy electrical characterization and identification of tumor cells. First, we studied the effects of the particle initial position and the sheath fluid compression on particle focusing. Then, the relationship of the particle height and the signal-to-noise ratio (SNR) of the impedance signal was explored. The results showed that efficient single-line focusing of 7–20 μm particles close to the electrodes was achieved and impedance signals with a high SNR and a low coefficient of variation (CV) were obtained. Finally, the electrical properties of three types of tumor cells (A549, MDA-MB-231, and UMUC-3 cells) were accurately characterized. Machine learning algorithms were implemented to accurately identify tumor cells based on the amplitude and phase opacities at multiple frequencies. Compared with traditional two-dimensional (2D) inertial focusing, the identification accuracy of A549, MDA-MB-231, and UM-UC-3 cells using our 3D inertial focusing increased by 57.5%, 36.4% and 36.6%, respectively. The impedance cytometer enables the detection of cells with a wide size range without causing clogging and obtains high SNR signals, improving applicability to different complex biological samples and cell identification accuracy. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Cell volume regulation modulates macrophage-related inflammatory responses via JAK/STAT signaling pathways.
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Yang, Xueying, Wang, Qifan, Shao, Fei, Zhuang, Zhumei, Wei, Ying, Zhang, Yang, Zhang, Lijun, Ren, Changle, and Wang, Huanan
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CELL size ,CELLULAR control mechanisms ,STEM cells ,POLYETHYLENE glycol ,GENETIC transcription - Abstract
Cell volume as a characteristic of changes in response to external environmental cues has been shown to control the fate of stem cells. However, its influence on macrophage behavior and macrophage-mediated inflammatory responses have rarely been explored. Herein, through mediating the volume of macrophages by adding polyethylene glycol (PEG), we demonstrated the feasibility of fine-tuning cell volume to regulate macrophage polarization towards anti-inflammatory phenotypes, thereby enabling to reverse macrophage-mediated inflammation response. Specifically, lower the volume of primary macrophages can induce both resting macrophages (M0) and stimulated pro-inflammatory macrophages (M1) to up-regulate the expression of anti-inflammatory factors and down-regulate pro-inflammatory factors. Further mechanistic investigation revealed that macrophage polarization resulting from changing cell volume might be mediated by JAK/STAT signaling pathway evidenced by the transcription sequencing analysis. We further propose to apply this strategy for the treatment of arthritis via direct introduction of PEG into the joint cavity to modulate synovial macrophage-related inflammation. Our preliminary results verified the credibility and effectiveness of this treatment evidenced by the significant inhibition of cartilage destruction and synovitis at early stage. In general, our results suggest that cell volume can be a biophysical regulatory factor to control macrophage polarization and potentially medicate inflammatory response, thereby providing a potential facile and effective therapy for modulating macrophage mediated inflammatory responses. Cell volume has recently been recognized as a significantly important biophysical signal in regulating cellular functionalities and even steering cell fate. Herein, through mediating the volume of macrophages by adding polyethylene glycol (PEG), we demonstrated the feasibility of fine-tuning cell volume to induce M1 pro-inflammatory macrophages to polarize towards anti-inflammatory M2 phenotype, and this immunomodulatory effect may be mediated by the JAK/STAT signaling pathway. We also proposed the feasible applications of this PEG-induced volume regulation approach towards the treatment of osteoarthritis (OA), wherein our preliminary results implied an effective alleviation of early synovitis. Our study on macrophage polarization mediated by cell volume may open up new pathways for immune regulation through microenvironmental biophysical clues. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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6. WOX11‐mediated cell size control in Arabidopsis attenuates growth and fecundity of endoparasitic cyst nematodes.
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Guarneri, Nina, Willig, Jaap‐Jan, Willemsen, Viola, Goverse, Aska, Sterken, Mark G., Nibbering, Pieter, Lozano Torres, José L., and Smant, Geert
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NEMATODE infections , *CYST nematodes , *SUGAR beet cyst nematode , *PLANT size , *CELL size - Abstract
SUMMARY Cyst nematodes establish permanent feeding structures called syncytia inside the host root vasculature, disrupting the flow of water and minerals. In response, plants form WOX11‐mediated adventitious lateral roots at nematode infection sites. WOX11 adventitious lateral rooting modulates tolerance to nematode infections; however, whether this also benefits nematode parasitism remains unknown. Here, we report on bioassays using a 35S::WOX11‐SRDX transcriptional repressor mutant to investigate whether WOX11 adventitious lateral rooting promotes syncytium development and thereby female growth and fecundity. Moreover, we chemically inhibited cellulose biosynthesis to verify if WOX11 directly modulates cell wall plasticity in syncytia. Finally, we performed histochemical analyses to test if WOX11 mediates syncytial cell wall plasticity via reactive oxygen species (ROS). Repression of WOX11‐mediated transcription specifically enhanced the radial expansion of syncytial elements, increasing both syncytium size and female offspring. The enhanced syncytial hypertrophy observed in the 35S::WOX11‐SRDX mutant could be phenocopied by chemical inhibition of cellulose biosynthesis and was associated with elevated levels of ROS at nematode infection sites. We, therefore, conclude that WOX11 restricts radial expansion of nematode‐feeding structures and female growth and fecundity, likely by modulating ROS‐mediated cell wall plasticity mechanisms. Remarkably, this novel role of WOX11 in plant cell size control is distinct from WOX11 adventitious lateral rooting underlying disease tolerance. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Inhibition of Hmbox1 Promotes Cardiomyocyte Survival and Glucose Metabolism Through Gck Activation in Ischemia/Reperfusion Injury.
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Yihua Bei, Yujiao Zhu, Jingwen Zhou, Songwei Ai, Jianhua Yao, Mingming Yin, Meiyu Hu, Weitong Qi, Spanos, Michail, Lin Li, Meng Wei, Zhenzhen Huang, Juan Gao, Chang Liu, van der Kraak, Petra H., Guoping Li, Zhiyong Lei, Sluijter, Joost P. G., and Junjie Xiao
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HUMAN embryonic stem cells , *CELL size , *MYOCARDIAL infarction , *TREATMENT effectiveness , *REPERFUSION injury - Abstract
(I/R) injury. Homeobox-containing 1 (Hmbox1), a homeobox family member, has been identified as a putative transcriptional repressor and is downregulated in the exercised heart. However, its roles in exercise-induced physiological cardiac growth and its potential protective effects against cardiac I/R injury remain largely unexplored. METHODS: We studied the function of Hmbox1 in exercise-induced physiological cardiac growth in mice after 4 weeks of swimming exercise. Hmbox1 expression was then evaluated in human heart samples from deceased patients with myocardial infarction and in the animal cardiac I/R injury model. Its role in cardiac I/R injury was examined in mice with adeno-associated virus 9 (AAV9) vector-mediated Hmbox1 knockdown and in those with cardiac myocyte--specific Hmbox1 ablation. We performed RNA sequencing, promoter prediction, and binding assays and identified glucokinase (Gck) as a downstream effector of Hmbox1. The effects of Hmbox1 together with Gck were examined in cardiomyocytes to evaluate their cell size, proliferation, apoptosis, mitochondrial respiration, and glycolysis. The function of upstream regulator of Hmbox1, ETS1, was investigated through ETS1 overexpression in cardiac I/R mice in vivo. RESULTS: We demonstrated that Hmbox1 downregulation was required for exercise-induced physiological cardiac growth. Inhibition of Hmbox1 increased cardiomyocyte size in isolated neonatal rat cardiomyocytes and human embryonic stem cell--derived cardiomyocytes but did not affect cardiomyocyte proliferation. Under pathological conditions, Hmbox1 was upregulated in both human and animal postinfarct cardiac tissues. Furthermore, both cardiac myocyte--specific Hmbox1 knockout and AAV9-mediated Hmbox1 knockdown protected against cardiac I/R injury and heart failure. Therapeutic effects were observed when sh-Hmbox1 AAV9 was administered after I/R injury. Inhibition of Hmbox1 activated the Akt/ mTOR/P70S6K pathway and transcriptionally upregulated Gck, leading to reduced apoptosis and improved mitochondrial respiration and glycolysis in cardiomyocytes. ETS1 functioned as an upstream negative regulator of Hmbox1 transcription, and its overexpression was protective against cardiac I/R injury. CONCLUSIONS: Our studies unravel a new role for the transcriptional repressor Hmbox1 in exercise-induced physiological cardiac growth. They also highlight the therapeutic potential of targeting Hmbox1 to improve myocardial survival and glucose metabolism after I/R injury. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Cytopathological findings of granular cell glioblastoma in intraoperative squash smear preparations: A case report.
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López‐Muñoz, Samuel, Sánchez‐Cordon, Borja, Taravilla‐Loma, Mario, and Esteban‐Rodríguez, Isabel
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PROGRESSIVE multifocal leukoencephalopathy , *MULTINUCLEATED giant cells , *BRAIN tumors , *CELL size , *CELL populations - Abstract
This article presents a case report on the cytopathological findings of granular cell glioblastoma (GCBG) in intraoperative squash smear preparations. GCBG is a rare and aggressive type of brain tumor that is difficult to diagnose. The article describes the microscopic features of GCBG, including the presence of large macrophage-like tumor cells with eosinophilic granular cytoplasm and distinct nucleoli. The authors emphasize the importance of caution in diagnosing GCBG and suggest communicating potential differential diagnoses to neurosurgeons. [Extracted from the article]
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- 2024
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9. SG12 regulates grain size by affecting cell proliferation in rice.
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Hu, Li, Zeng, Jierui, Diao, Xue, Zhong, Yutong, Zhou, Xiaorong, Wang, Hao, Hu, Xiaoling, and Yuan, Hua
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GRAIN size , *PHOSPHOPROTEIN phosphatases , *MOLECULAR size , *PROTEIN structure , *CELL size , *HYBRID rice - Abstract
The grain size of rice (
Oryza sativa) plays a pivotal role in determining yield. It is crucial to explore the genes related to grain size and analyze their molecular mechanisms to enhance rice yield further. This study identified a small‐grain mutant small grain 12 (sg12 ), from the ethyl methanesulfonate‐induced mutant library of Shuhui 498, a backbone parent of heavy‐panicle hybrid rice. We found thatsg12 rice mutant exhibits a decrease in grain size and 1000‐grain weight, but an increase in grain number per panicle. Genetic analysis indicated that the small grain ofsg12 is controlled by a pair of semi‐dominant genes. Furthermore, cytological analysis showed that the number of longitudinal cells in the spikelet hull ofsg12 decreased, indicating thatSG12 regulates grain size by affecting cell proliferation. In this study, we also identified a candidate gene ofSG12 asOsPPKL3 , which encodes a putative protein phosphatase with Kelch‐like repeat domains. A single‐nucleotide polymorphism substitution (G/A) occurred in the conserved Kelch domain of OsPPKL3 in thesg12 , resulting in the mutation of the 176th amino acid from Ala to Thr, and this amino acid substitution led to significant differences in the three‐dimensional structure of the OsPPKL3 protein. Finally, genetic analysis indicated thatOsPPKL3 regulates grain size independent ofOryza sativa BRI1‐associated receptor kinase 1 (OsBAK1 ) andOryza sativa Brassinosteroid‐signaling kinase 2 (OsBSK2 ). Overall, this study identified a new allelic mutant ofOsPPKL3 , clarified the cytological basis ofOsPPKL3 regulating grain size, and emphasized the crucial role of the 176th amino acid in the Kelch domain of OsPPKL3 for its biological function. Our results provided important resources for further studying the molecular mechanisms ofOsPPKL3 regulating grain size in rice. [ABSTRACT FROM AUTHOR]- Published
- 2024
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10. Multiscale simulation of rarefied gas dynamics via direct intermittent GSIS-DSMC coupling.
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Luo, Liyan and Wu, Lei
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RAREFIED gas dynamics ,BOLTZMANN'S equation ,CELL size - Abstract
The general synthetic iterative scheme (GSIS) has proven its efficacy in modeling rarefied gas dynamics, where the steady-state solutions are obtained after dozens of iterations of the Boltzmann equation, with minimal numerical dissipation even using large spatial cells. In this paper, the fast convergence and asymptotic-preserving properties of the GSIS are harnessed to remove the limitations of the direct simulation Monte Carlo (DSMC) method. The GSIS, which leverages high-order constitutive relations derived from DSMC, is applied intermittently, which not only rapidly steers the DSMC towards steady state, but also eliminates the requirement that the cell size must be smaller than the molecular mean free path. Several numerical tests have been conducted to validate the accuracy and efficiency of this hybrid GSIS-DSMC approach. [ABSTRACT FROM AUTHOR]
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- 2024
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11. The longevity factor spermidine is part of a highly heritable complex erythrocyte phenotype associated with longevity.
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Kaminsky, Cameron J., Mill, Jericha, Patel, Viharkumar, Pierce, Dylan, Haj, Amelia, Hess, Aaron S., Li, Lingjun, and Raife, Thomas
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CELL size , *SPERMIDINE , *ENERGY metabolism , *DATABASES , *BIOMOLECULES , *LONGEVITY - Abstract
Extreme longevity in humans is known to be a heritable trait. In a well‐established twin erythrocyte metabolomics and proteomics database, we identified the longevity factor spermidine and a cluster of correlated molecules with high heritability estimates. Erythrocyte spermidine is 82% heritable and significantly correlated with 59 metabolites and 22 proteins. Thirty‐eight metabolites and 19 proteins were >20% heritable, with a mean heritability of 61% for metabolites and 49% for proteins. Correlated metabolites are concentrated in energy metabolism, redox homeostasis, and autophagy pathways. Erythrocyte mean cell volume (MCV), an established heritable trait, was consistently negatively correlated with the top 25 biomolecules most strongly correlated with spermidine, indicating that smaller MCVs are associated with higher concentrations of spermidine and correlated molecules. Previous studies have linked larger MCVs with poorer memory, cognition, and all‐cause mortality. Analysis of 432,682 unique patient records showed a linear increase in MCV with age but a significant deviation toward smaller than expected MCVs above age 86, suggesting that smaller MCVs are associated with extreme longevity. Consistent with previous reports, a subset of 78,158 unique patient records showed a significant skewing toward larger MCV values in a deceased cohort compared to an age‐matched living cohort. Our study supports the existence of a complex, heritable phenotype in erythrocytes associated with health and longevity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. Size-related variability of oxygen consumption rates in individual human hepatic cells.
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Botte, Ermes, Cui, Yuan, Magliaro, Chiara, Tenje, Maria, Koren, Klaus, Rinaldo, Andrea, Stocker, Roman, Behrendt, Lars, and Ahluwalia, Arti
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OXYGEN consumption , *LIVER cells , *AEROBIC capacity , *CELL culture , *CELL size , *CELL populations - Abstract
Accurate descriptions of the variability in single-cell oxygen consumption and its size-dependency are key to establishing more robust tissue models. By combining microfabricated devices with multiparameter identification algorithms, we demonstrate that single human hepatocytes exhibit an oxygen level-dependent consumption rate and that their maximal oxygen consumption rate is significantly lower than that of typical hepatic cell cultures. Moreover, we found that clusters of two or more cells competing for a limited oxygen supply reduced their maximal consumption rate, highlighting their ability to adapt to local resource availability and the presence of nearby cells. We used our approach to characterize the covariance of size and oxygen consumption rate within a cell population, showing that size matters, since oxygen metabolism covaries lognormally with cell size. Our study paves the way for linking the metabolic activity of single human hepatocytes to their tissue- or organ-level metabolism and describing its size-related variability through scaling laws. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Phenotyping of single plant cells on a microfluidic cytometry platform with fluorescent, mechanical, and electrical modules.
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Zhang, Shuaihua, Zhang, Tianjiao, Wang, Shuaiqi, Han, Ziyu, Duan, Xuexin, and Wang, Jiehua
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PLANT protoplasts , *CYTOMETRY , *ELECTRIC impedance , *CELL size , *REACTIVE oxygen species , *FLOW cytometry - Abstract
Compared to animal cells, phenotypic characterization of single plant cells on microfluidic platforms is still rare. In this work, we collated population statistics on the morphological, biochemical, physical and electrical properties of Arabidopsis protoplasts under different external and internal conditions, using progressively improved microfluidic platforms. First, we analyzed the different effects of three phytohormones (auxin, cytokinin and gibberellin) on the primary cell wall (PCW) regeneration process using a microfluidic flow cytometry platform equipped with a single-channel fluorescence sensor. Second, we correlated the intracellular reactive oxygen species (ROS) level induced by heavy metal stress with the concurrent PCW regeneration process by using a dual-channel fluorescence sensor. Third, by integrating contraction channels, we were able to effectively discriminate variations in cell size while monitoring the intensity of intracellular ROS signaling. Fourth, by combining an electrical impedance electrode with the contraction channel, we analyzed the differences in electrical and mechanical properties of wild-type and mutant plant cells before and after primary cell wall regeneration. Overall, our work demonstrates the feasibility and sensitivity of microfluidic flow cytometry in high-throughput phenotyping of plant cells and provides a reference for assessing metabolic and physiological indicators of individual plant cells in multiple dimensions. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Multifunctional aggregation network of cell nuclei segmentation aiming histopathological diagnosis assistance: A new MA-Net construction.
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Pu, Qiumei, Tian, Jinglong, Wei, Donghao, Shu, Qingming, Sun, Minghui, and Zhao, Lina
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COMPUTER-aided diagnosis , *CELL morphology , *CELL size , *CELL aggregation , *HEMATOXYLIN & eosin staining - Abstract
Automated diagnostic systems can enhance the accuracy and efficiency of pathological diagnoses, nuclear segmentation plays a crucial role in computer-aided diagnosis systems for histopathology. However, achieving accurate nuclear segmentation is challenging due to the complex background tissue structures and significant variations in cell morphology and size in pathological images. In this study, we have proposed a U-Net based deep learning model, called MA-Net(Multifunctional Aggregation Network), to accurately segmenting nuclei from H&E stained images. In contrast to previous studies that focused on improving a single module of the network, we applied feature fusion modules, attention gate units, and atrous spatial pyramid pooling to the encoder and decoder, skip connections, and bottleneck of U-Net, respectively, to enhance the network's performance in nuclear segmentation. The dice coefficient loss was used during model training to enhance the network's ability to segment small objects. We applied the proposed MA-Net to multiple public datasets, and comprehensive results showed that this method outperforms the original U-Net method and other state-of-the-art methods in nuclei segmentation tasks. The source code of our work can be found in https://github.com/LinaZhaoAIGroup/MA-Net. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. The role of bacterial size, shape and surface in macrophage engulfment of uropathogenic E. coli cells.
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Peterson, Elizabeth, Söderström, Bill, Prins, Nienke, Le, Giang H. B., Hartley-Tassell, Lauren E., Evenhuis, Chris, Grønnemose, Rasmus Birkholm, Andersen, Thomas Emil, Møller-Jensen, Jakob, Iosifidis, Gregory, Duggin, Iain G., Saunders, Bernadette, Harry, Elizabeth J., and Bottomley, Amy L.
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ESCHERICHIA coli , *URINARY tract infections , *CELL morphology , *CELL size , *URODYNAMICS ,REPRODUCTIVE isolation - Abstract
Uropathogenic Escherichia coli (UPEC) can undergo extensive filamentation in the host during acute urinary tract infections (UTIs). It has been hypothesised that this morphological plasticity allows bacteria to avoid host immune responses such as macrophage engulfment. However, it is still unclear what properties of filaments are important in macrophage-bacteria interactions. The aim of this work was to investigate the contribution of bacterial biophysical parameters, such as cell size and shape, and physiological parameters, such as cell surface and the environment, to macrophage engulfment efficiency. Viable, reversible filaments of known lengths and volumes were produced in the UPEC strain UTI89 using a variety of methods, including exposure to cell-wall targeting antibiotics, genetic manipulation and isolation from an in vitro human bladder cell model. Quantification of the engulfment ability of macrophages using gentamicin-protection assays and fluorescence microscopy demonstrated that the ability of filaments to avoid macrophage engulfment is dependent on a combination of size (length and volume), shape, cell surface and external environmental factors. UTI89 filamentation and macrophage engulfment efficiency was also found to occur independently of the SOS-inducible filamentation genes, sulA and ymfM in both in vivo and in vitro models of infection. Compared to filaments formed via antibiotic inhibition of division, the infection-derived filaments were preferentially targeted by macrophages. With several strains of UPEC now resistant to current antibiotics, our work identifies the importance of bacterial physiological and morphological states during infection. Author summary: Urinary tract infections (UTIs) are one of the most common bacterial infections worldwide with 50% of women suffering from a UTI during their lifetime. Escherichia coli is the primary bacteria responsible for UTIs and is usually found in short rod forms. However, during UTIs E. coli can elongate into extremely long thin shapes called 'filaments'. Filaments are thought to be advantageous during infections because they are too long to be engulfed and killed by immune cells called macrophages. Due to increasing antibiotic resistance in bacteria there is a strong need for the discovery of new ways to treat infections and this is only possible once we thoroughly understand the mechanisms bacteria employ to overcome our immune response. Therefore, we investigated the effect of E. coli filamentation on macrophage engulfment along with other aspects of bacteria reported to influence engulfment. We found that the ability of filaments to avoid macrophage engulfment is dependent on a combination of size (length and volume), shape, surface and external environmental factors. Our research has highlighted the importance of bacterial shape changes during infections and provided a foundational understanding of macrophage engulfment of filaments. Eventually, this knowledge may reveal new targets for treatment of infections. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Enhancing the reliability of a robotic arm through lightweighting and vibration control with modal analysis and topology optimization.
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Alshihabi, Mamoun, Ozkahraman, Merdan, and Kayacan, Mevlüt Yunus
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FUSED deposition modeling , *ROBOTICS , *FINITE element method , *UNIT cell , *CELL size - Abstract
AbstractThis study investigates the integration of modal analysis and topology optimization in the design of a robotic arm to enhance both its reliability and efficiency. The primary objectives are to reduce the weight and minimize the vibration of the robotic arm. Initially, the kinematics and dynamics of the robotic arm were examined to identify the joint experiencing the highest torque. Finite element analyses (FEA) were then conducted on this critical joint to assess its vibration characteristics and redesign the joint for improved performance through topology optimization. Comparative analysis of the initial and optimized designs has highlighted significant improvements in weight reduction and vibration control. The selected robot arm component was manufactured using fused deposition modeling (FDM). Experimental modal analysis validated the theoretical predictions, demonstrating the effectiveness of the optimized design. The selected component of the robotic arm was redesigned using three different topology geometries and two different unit cell sizes for each, resulting in a maximum weight reduction of 29.37%. Stresses were reduced by 41% under critical operating conditions, which contributed significantly to the system’s reliability. The improvements in efficiency were measured through reductions in weight and vibration, demonstrating the enhanced dynamic performance of the robotic arm. The optimized design was validated through experimental modal analysis, confirming the effectiveness of the redesign. This study underscores the synergy of modal analysis and topology optimization in advancing robotic arm technology, providing a comprehensive approach to design optimization for enhanced reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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17. An unscheduled switch to endocycles induces a reversible senescent arrest that impairs growth of the Drosophila wing disc.
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Huang, Yi-Ting, Hesting, Lauren L., and Calvi, Brian R.
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CELL division , *WOUND healing , *CELL size , *PLANT cells & tissues , *DNA damage - Abstract
A programmed developmental switch to G / S endocycles results in tissue growth through an increase in cell size. Unscheduled, induced endocycling cells (iECs) promote wound healing but also contribute to cancer. Much remains unknown, however, about how these iECs affect tissue growth. Using the D. melanogaster wing disc as model, we find that populations of iECs initially increase in size but then subsequently undergo a heterogenous arrest that causes severe tissue undergrowth. iECs acquired DNA damage and activated a Jun N-terminal kinase (JNK) pathway, but, unlike other stressed cells, were apoptosis-resistant and not eliminated from the epithelium. Instead, iECs entered a JNK-dependent and reversible senescent-like arrest. Senescent iECs promoted division of diploid neighbors, but this compensatory proliferation did not rescue tissue growth. Our study has uncovered unique attributes of iECs and their effects on tissue growth that have important implications for understanding their roles in wound healing and cancer. Author summary: The endocycle is an alternative growth program during which cells increase in size and repeatedly duplicate their DNA without dividing. The switch from cell division cycles to endocycles occurs normally during development of many tissues across plants and animals including humans. Cells can also switch to unscheduled endocycles in response to various conditions. Evidence suggests that this switch is beneficial for wound healing, but also can have pathological effects, most notably in cancer. Much remains unknown, however, about the regulation of these unscheduled endocycles and their impact on tissue growth. Using the Drosophila larval wing disc as model, we have found that unscheduled endocycles are limited in their growth by a specific type of senescent arrest that is mediated by a Jun Kinase stress pathway, which results in severe deleterious effects on tissue growth. We found that these arrested endocycling cells can go back to error prone divisions that compromise genomic DNA integrity, and can also promote the division of neighboring cells. Our study has revealed new inherent properties of unscheduled endocycling cells that impact tissue growth, with important implications for understanding their contribution to wound healing and cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Single-cell and spatial sequencing identifies senescent and germinal tumor cells in adamantinomatous craniopharyngiomas.
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Wang, Xianlong, Lin, Jincheng, Liu, Hongxing, Zhao, Chuan, Tu, Zhiwei, Xu, Dapeng, Zhang, En, Zhou, Zhongqing, Qi, Xueling, Wang, Xingfu, and Lin, Zhixiong
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CYTOTOXIC T cells , *HEMATOXYLIN & eosin staining , *RNA analysis , *CELL size , *STEM cells - Abstract
Adamantinomatous craniopharyngioma (ACP) is a clinically aggressive tumor without effective treatment method. Previous studies proposed a paracrine tumorigenesis model, in which oncogenic β-catenin induces senescence in pituitary stem cells and the senescent cells lead the formation of paracrine tumors through secretion of pro-tumorigenic factors. However, there lacks characterization on senescent cells in ACPs. Here, we profiled 12 ACPs with single-cell RNA and TCR-sequencing to elucidate the cellular atlas in ACPs and 3 of them were also subject to spatial sequencing to localize different subpopulations of the tumor cells. In total, we obtained the transcriptome profiles of 70,682 cells. Tumor cells, which were unambiguously identified through the cellular mutation status of the driver CTNNB1 mutations, were clustered into 6 subsets. The whorl-like cluster (WC) cells show distinct molecular features from the other tumor cells and the palisading epithelium (PE) cells consists of a proliferating subset. Other than typical PE and WC, we identified two novel subpopulations of the tumor cells. In one subpopulation, the cells express a high level of cytokines, e.g., FDCSP and S100A8/A9, and are enriched with the senescence-associated secretory phenotype (SASP) factors. Hematoxylin and eosin staining reveals that these SASP cells lack an ordered structures and their nuclei are elongated. In the other subpopulation, the cell sizes are small and they are tightly packed together with an unusual high density expressing a high level of mitochondrial genes (median 10.9%). These cells are the origin of the tumor developmental trajectories revealed by RNA velocity and pseudo-time analysis. Single-cell RNA and TCR analysis reveals that some ACPs are infiltrated with clonally expanded cytotoxic T cells. We propose a hypothesis that WC and PE are formed via different negative regulation mechanisms of the overactivated WNT/β-catenin signaling which provides a new understanding on the tumorigenesis of ACPs. The study lays a foundation for future studies on targeting senescent cells in ACPs with senolytic compounds or other therapeutic agents. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Cell tracking -based framework for assessing nowcasting model skill in reproducing growth and decay of convective rainfall.
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Ritvanen, Jenna, Pulkkinen, Seppo, Moisseev, Dmitri, and Nerini, Daniele
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RAINFALL , *MACHINE learning , *CELL size - Abstract
The rapid temporal evolution of convective rainfall poses a challenge for rainfall nowcasting models. With the growing potential of machine learning models for precipitation nowcasting to produce realistic-looking nowcasts for long lead times, it is important to investigate whether the nowcasts also produce realistic development for convective rainfall. Common verification metrics traditionally used to validate nowcasting models are often dominated by large-scale stratiform rainfall, and averaging the metrics across entire precipitation fields obscures how accurately the models replicate individual convective cells, which makes it difficult to distinguish the model skill for the growth and decay of convective rainfall. In this study, we present a convective cell tracking-based framework to investigate how accurately nowcasting models reproduce the development of convective rainfall. The framework consists of first identifying and tracking the convective cells in the input observation rainfall fields, and then identifying and tracking the cells separately in the target observations and the nowcast rainfall fields by continuing the cell tracks identified in the observations. Features describing the cells and cell tracks, such as the cell volume rain rate and area, are then extracted. In addition to the errors in these feature values, the models' skill in reproducing the existence of convective cells is estimated by calculating several contingency-table metrics, such as the Critical Success Index. The results allow the analysis of how accurately the models reproduce the growth and decay of convective rainfall and quantify the differences between the models, for example, due to differences in how the models smooth the nowcasts, i.e., blurring. The framework also allows differentiation of the results based on the initial conditions of the cell tracks, demonstrated here by separating the tracks into decaying or growing cell tracks based on the cell status when the nowcast is created. The framework is demonstrated using four open-source advection-based models: the advection nowcast, S-PROG, and LINDA implemented in the pysteps library, and L-CNN, with data from the Swiss radar network. The results indicate that the L-CNN model reproduced the existence of convective cells best among the models and had smaller errors in the cell volume rain rate than LINDA and S-PROG. LINDA had the smallest underestimation in the cell mean rain rate, whereas S-PROG significantly overestimated the cell volume rain rate and area because of blurring. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Aquaporin-3a Dysfunction Impairs Osmoadaptation in Post-Activated Marine Fish Spermatozoa.
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Chauvigné, François, Castro-Arnau, Júlia, López-Fortún, Noelia, Sánchez-Chardi, Alejandro, Rützler, Michael, Calamita, Giuseppe, Finn, Roderick Nigel, and Cerdà, Joan
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CELL size , *FISH spermatozoa , *MARINE fishes , *MAMMAL fertility , *SPARUS aurata , *SPERMATOZOA , *ION channels - Abstract
Spermatozoon volume regulation is an essential determinant of male fertility competence in mammals and oviparous fishes. In mammals, aquaporin water channels (AQP3, -7 and -8) have been suggested to play a role in spermatozoon cell volume regulatory responses in the hypotonic female oviduct. In contrast, the ejaculated spermatozoa of marine teleosts, such as the gilthead seabream (Sparus aurata), experience a high hypertonic shock in seawater, initially resulting in an Aqp1aa-mediated water efflux, cell shrinkage and the activation of motility. Further regulatory recovery of cell volume in post-activated spermatozoa is mediated by Aqp4a in cooperation with the Trpv4 Ca2+ channel and other ion channels and transporters. Using a paralog-specific antibody, here, we show that seabream spermatozoa also express the aquaglyceroporin AQP3 ortholog Aqp3a, which is highly accumulated in the mid posterior region of the spermatozoon flagella, in a similar pattern to that described in mouse and human sperm. To investigate the role of Aqp3a in seabream sperm motility, we used a recently developed AQP3 antagonist (DFP00173), as well as the seabream Aqp3a-specific antibody (α-SaAqp3a), both of which specifically inhibit Aqp3a-mediated water conductance when the channel was heterologously expressed in Xenopus laevis oocytes. Inhibition with either DFP00173 or α-SaAqp3a did not affect sperm motility activation but did impair the spermatozoon motion kinetics at 30 s post activation in a dose-dependent manner. Interestingly, in close resemblance to the phenotypes of AQP3-deficient murine sperm, electron microscopy image analysis revealed that both Aqp3a inhibitors induce abnormal sperm tail morphologies, including swelling and angulation of the tail, with complete coiling of the flagella in some cases. These findings suggest a conserved role of Aqp3a as an osmosensor that regulates cell volume in fish spermatozoa under a high hypertonic stress, thereby controlling the efflux of water and/or solutes in the post-activated spermatozoon. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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21. Mining Candidate Genes for Leaf Angle in Brassica napus L. by Combining QTL Mapping and RNA Sequencing Analysis.
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Peng, Aoyi, Li, Shuyu, Wang, Yuwen, Cheng, Fengjie, Chen, Jun, Zheng, Xiaoxiao, Xiong, Jie, Ding, Ge, Zhang, Bingchao, Zhai, Wen, Song, Laiqiang, Wei, Wenliang, and Chen, Lunlin
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LOCUS (Genetics) , *RNA analysis , *CELL metabolism , *CELL size , *CELL junctions - Abstract
Leaf angle (LA) is an important trait of plant architecture, and individuals with narrow LA can better capture canopy light under high-density planting, which is beneficial for increasing the overall yield per unit area. To study the genetic basis and molecular regulation mechanism of leaf angle in rapeseed, we carried out a series of experiments. Quantitative trait loci (QTL) mapping was performed using the RIL population, and seven QTLs were identified. Transcriptome analysis showed that the cell wall formation/biogenesis processes and biosynthesis/metabolism of cell wall components were the most enrichment classes. Most differentially expressed genes (DEGs) involved in the synthesis of lignin, xylan, and cellulose showed down-regulated expression in narrow leaf material. Microscopic analysis suggested that the cell size affected by the cell wall in the junction area of the stem and petiole was the main factor in leaf petiole angle (LPA) differences. Combining QTL mapping and RNA sequencing, five promising candidate genes BnaA01G0125600ZS, BnaA01G0135700ZS, BnaA01G0154600ZS, BnaA10G0154200ZS, and BnaC03G0294200ZS were identified in rapeseed, and most of them were involved in cell wall biogenesis and the synthesis/metabolism of cell wall components. The results of QTL, transcriptome analysis, and cytological analysis were highly consistent, collectively revealing that genes related to cell wall function played a crucial role in regulating the LA trait in rapeseed. The study provides further insights into LA traits, and the discovery of new QTLs and candidate genes is highly beneficial for genetic improvement. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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22. Mitochondrial VDAC1 Silencing in Urethane-Induced Lung Cancer Inhibits Tumor Growth and Alters Cancer Oncogenic Properties.
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Melnikov, Nataly, Pittala, Srinivas, Shteinfer-Kuzmine, Anna, and Shoshan-Barmatz, Varda
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MITOCHONDRIA , *RESEARCH funding , *ANTINEOPLASTIC agents , *APOPTOSIS , *MAGNETIC resonance imaging , *FLUORESCENT antibody technique , *TUMOR markers , *XENOGRAFTS , *METABOLIC reprogramming , *GENE expression , *MICE , *INTRAVENOUS therapy , *CELL culture , *LUNG tumors , *DRUG efficacy , *ANIMAL experimentation , *CARCINOGENS , *GROWTH factors , *STEM cells , *CELL size , *STAINS & staining (Microscopy) , *MEMBRANE proteins , *NANOPARTICLES - Abstract
Simple Summary: Cancer cells exhibit several key characteristics, including uncontrolled growth, altered metabolism, enhanced survival mechanisms, and resistance to apoptosis, all of which are crucial for their persistence. In our study, we explored the impact of disrupting the production of mitochondrial gatekeeper protein VDAC1 on lung cancer. We induced lung cancer in mice using the chemical urethane, which closely mimics human lung cancer in terms of genetic mutations and molecular changes. Using MRI to monitor the lung tumors, we found that inhibiting VDAC1 expression in this mouse model led to significant changes: reprogramming of cancer cell metabolism, reduced tumor growth, alterations in the tumor microenvironment, and elimination of cancer stem cells (CSCs). Additionally, treatment with a peptide derived from VDAC1 also inhibited tumor growth and decreased CSC markers. These findings suggest that targeting VDAC1, either through depletion or with a cell-penetrating peptide, could be a promising therapeutic approach for lung cancer. Alterations in cellular metabolism are vital for cancer cell growth and motility. Here, we focused on metabolic reprogramming and changes in tumor hallmarks in lung cancer by silencing the expression of the mitochondrial gatekeeper VDAC1. To better mimic the clinical situation of lung cancer, we induced lung cancer in A/J mice using the carcinogen urethane and examined the effectiveness of si-m/hVDAC1-B encapsulated in PLGA-PEI nanoparticles. si-m/hVDAC1-B, given intravenously, induced metabolism reprogramming and inhibited tumor growth as monitored using MRI. Mice treated with non-targeted (NT) PLGA-PEI-si-NT showed many large size tumors in the lungs, while in PLGA-PEI-si-m/hVDAC-B-treated mice, lung tumor number and area were markedly decreased. Immunofluorescence staining showed decreased expression of VDAC1 and metabolism-related proteins and altered expression of cancer stem cell markers. Morphological analysis showed two types of tumors differing in their morphology; cell size and organization within the tumor. Based on specific markers, the two tumor types were identified as small cell (SCLC) and non-small cell (NSCLC) lung cancer. These two types of tumors were found only in control tumors, suggesting that PLGA-PEI-si-m/hVDAC1-B also targeted SCLC. Indeed, using a xenograft mouse model of human-derived SCLC H69 cells, si-m/hVDAC1-B inhibited tumor growth and reduced the expression of VDAC1 and energy- and metabolism-related enzymes, and of cancer stem cells in the established xenograft. Additionally, intravenous treatment of urethane-induced lung cancer mice with the VDAC1-based peptide, Retro-Tf-D-LP4, showed inhibition of tumor growth, and decreased expression levels of metabolism- and cancer stem cells-related proteins. Thus, silencing VDAC1 targeting both NSCLC and SCLC points to si-VDAC1 as a possible therapeutic tool to treat these lung cancer types. This is important as target NSCLC tumors undergo transformation to SCLC. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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23. Activation of Yes-Associated Protein Is Indispensable for Transformation of Kidney Fibroblasts into Myofibroblasts during Repeated Administration of Cisplatin.
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Yu, Jia-Bin, Padanilam, Babu J., and Kim, Jinu
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YAP signaling proteins , *CELLULAR aging , *CELL size , *ACUTE kidney failure , *CHRONIC kidney failure - Abstract
Cisplatin is a potent chemotherapy medication that is used to treat various types of cancer. However, it can cause nephrotoxic side effects, which lead to acute kidney injury (AKI) and subsequent chronic kidney disease (CKD). Although a clinically relevant in vitro model of CKD induced by repeated administration of low-dose cisplatin (RAC) has been established, its underlying mechanisms remain poorly understood. Here, we compared single administration of high-dose cisplatin (SAC) to repeated administration of low-dose cisplatin (RAC) in myofibroblast transformation and cellular morphology in a normal rat kidney fibroblast NRK-49F cell line. RAC instead of SAC transformed the fibroblasts into myofibroblasts as determined by α-smooth muscle actin, enlarged cell size as represented by F-actin staining, and increased cell flattening as expressed by the semidiameter ratio of attached cells to floated cells. Those phenomena, as well as cellular senescence, were significantly detected from the time right before the second administration of cisplatin. Interestingly, inhibition of the interaction between Yes-associated protein (YAP) and the transcriptional enhanced associated domain (TEAD) using Verteporfin remarkedly reduced cell size, cellular senescence, and myofibroblast transformation during RAC. These findings collectively suggest that YAP activation is indispensable for cellular hypertrophy, senescence, and myofibroblast transformation during RAC in kidney fibroblasts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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24. Prolonged exposure to hypergravity increases number and size of cells and enhances lignin deposition in the stem of Arabidopsis thaliana.
- Author
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Shinohara, Hironori, Muramoto, Masaki, Tamaoki, Daisuke, Kamachi, Hiroyuki, Inoue, Hiroshi, Kume, Atsushi, and Karahara, Ichirou
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LIGNINS , *CELL size , *CAMBIUM , *XYLEM , *PHLOEM - Abstract
We have performed a lab-based hypergravity cultivation experiment using a centrifuge equipped with a lighting system and examined long-term effects of hypergravity on the development of the main axis of the Arabidopsis (Arabidopsis thaliana (L.) Heynh.) primary inflorescence, which comprises the rachis and peduncle, collectively referred to as the main stem for simplicity. Plants grown under 1 × g (gravitational acceleration on Earth) conditions for 20–23 days and having the first visible flower bud were exposed to hypergravity at 8 × g for 10 days. We analyzed the effect of prolonged hypergravity conditions on growth, lignin deposition, and tissue anatomy of the main stem. As a result, the length of the main stem decreased and cross-sectional area, dry mass per unit length, cell number, and lignin content of the main stem significantly increased under hypergravity. Lignin content in the rosette leaves also increased when they were exposed to hypergravity during their development. Except for interfascicular fibers, cross-sectional areas of the tissues composing the internode significantly increased under hypergravity in most types of the tissues in the basal part than the apical part of the main stem, indicating that the effect of hypergravity is more pronounced in the basal part than the apical part. The number of cells in the fascicular cambium and xylem significantly increased under hypergravity both in the apical and basal internodes of the main stem, indicating a possibility that hypergravity stimulates procambium activity to produce xylem element more than phloem element. The main stem was suggested to be strengthened through changes in its morphological characteristics as well as lignin deposition under prolonged hypergravity conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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25. A Hybridization Chain Reaction-Based Electrochemical Biosensor for Highly Sensitive and Selective Detection of miR-378.
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Wang, Qian, Fan, Bingyuan, Wang, Shan, Liang, Yan, Gao, Yahui, Fu, Xinrui, Zhang, Xiang, Meng, Wei, and Hu, Fang
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BIOMARKERS , *TUMOR markers , *REGULATOR genes , *GOLD nanoparticles , *CELL size , *BIOSENSORS - Abstract
In recent years, microRNAs have been used as cancer markers in clinical testing. In this study, an electrochemical biosensor was developed based on nanomaterials and the hybridization chain reaction (HCR) for highly sensitive and selective detection of the target miR-378 using K3Fe(CN)6/K4Fe(CN)6 as a redox indicator. MiR-378 is located on human chromosome 5q32 and serves as an important gene regulatory locus. Recent studies have found that aberrant expression of miR-378 is associated with cervical cancer, breast cancer, lung cancer, and other diseases. HCR is a simple and efficient isothermal amplification technique that does not require enzyme mediation and can be performed at room temperature. Evaluations of the specificity, stability, and sensitivity of the developed sensor revealed its ability to rapidly and specifically detect miR-378 in two hours with a detection limit as low as 100 cells in a volume of 400 µL, thereby indicating that this device could provide a novel approach for clinical diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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26. Spatiotemporal analysis of multi-scale cell structure in spheroid culture reveals hypertrophic chondrocyte differentiation.
- Author
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Tomida, Kosei, Kim, Jeonghyun, Maeda, Eijiro, Adachi, Taiji, and Matsumoto, Takeo
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CELL size , *CELL anatomy , *IMAGE analysis , *THREE-dimensional imaging , *CHROMATIN - Abstract
3D cell culture has emerged as a promising approach to replicate the complex behaviors of cells within living organisms. This study aims to analyze spatiotemporal behavior of the morphological characteristics of cell structure at multiscale in 3D scaffold-free spheroids using chondrogenic progenitor ATDC5 cells. Over a 14-day culture period, it exhibited cell hypertrophy in the spheroids regarding cellular and nuclear size as well as changes in morphology. Moreover, biological analysis indicated a signification up-regulation of normal chondrocyte as well as hypertrophic chondrocyte markers, suggesting early hypertrophic chondrocyte differentiation. Cell nuclei underwent changes in volume, sphericity, and distribution in spheroid over time, indicating alterations in chromatin organization. The ratio of chromatin condensation volume to cell nuclear volume decreased as the cell nuclei enlarged, potentially signifying changes in chromatin state during hypertrophic chondrocyte differentiation. Our image analysis techniques in this present study enabled detailed morphological measurement of cell structure at multi-scale, which can be applied to various 3D culture models for in-depth investigation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. KBAscope: key biodiversity area identification in R.
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Spiliopoulou, Konstantina, Rigal, François, Plumptre, Andrew J., Trigas, Panayiotis, Paragamian, Kaloust, Hochkirch, Axel, Lymberakis, Petros, Portolou, Danae, Stoumboudi, Maria Th., and Triantis, Kostas A.
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GRID cells , *DATA editing , *SUSTAINABLE development , *CELL size , *HABITATS - Abstract
Key Biodiversity Areas (KBAs) represent the largest global network of sites critical to the persistence of biodiversity, which have been identified against standardised quantitative criteria. Sites that hold very high biodiversity value or potential are given specific attention on site‐based conservation targets of the Kunming‐Montreal Global Biodiversity Framework (GBF), and KBAs are already used in indicators for the GBF and the Sustainable Development Goals. However, most of the species that trigger KBA status are birds and to maximise benefits for biodiversity under the actions taken to fulfil the GBF, countries need to update their KBAs to represent important sites across multiple taxa. Here we introduce KBAscope, an R package to identify potential KBAs using multiple taxonomic groups. KBAscope provides flexible, user‐friendly functions to edit species data (population, range maps, area of occupancy, area of habitat and localities); apply KBA criteria; and generate outputs to support the delineation and validation of KBAs. The details of the analysis – such as the spatial units tested or the KBA criteria applied – can be decided according to the scope of the analysis. We demonstrate the functionality of KBAscope by using it to identify potential KBAs in Greece based on multiple terrestrial taxonomic groups and four sizes of grid cells (4 km2, 25 km2, 100 km2, 225 km2). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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28. Endothelin-1 influences mechanical properties and contractility of hiPSC derived cardiomyocytes resulting in diastolic dysfunction.
- Author
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Redwanz, Caterina, Pires, Ricardo H., Biedenweg, Doreen, Groß, Stefan, Otto, Oliver, and Könemann, Stephanie
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INDUCED pluripotent stem cells , *PHASE-contrast microscopy , *CARDIAC hypertrophy , *CELLULAR mechanics , *CELL size , *DIASTOLE (Cardiac cycle) - Abstract
A better understanding of the underlying pathomechanisms of diastolic dysfunction is crucial for the development of targeted therapeutic options with the aim to increase the patients' quality of life. In order to shed light on the processes involved, suitable models are required. Here, effects of endothelin-1 (ET-1) treatment on cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) were investigated. While it is well established, that ET-1 treatment induces hypertrophy in cardiomyocytes, resulting changes in cell mechanics and contractile behavior with focus on relaxation have not been examined before. Cardiomyocytes were treated with 10 nM of ET-1 for 24 h and 48 h, respectively. Hypertrophy was confirmed by real-time deformability cytometry (RT-DC) which was also used to assess the mechanical properties of cardiomyocytes. For investigation of the contractile behavior, 24 h phase contrast video microscopy was applied. To get a deeper insight into changes on the molecular biological level, gene expression analysis was performed using the NanoString nCounter® cardiovascular disease panel. Besides an increased cell size, ET-1 treated cardiomyocytes are stiffer and show an impaired relaxation. Gene expression patterns in ET-1 treated hiPSC derived cardiomyocytes showed that pathways associated with cardiovascular diseases, cardiac hypertrophy and extracellular matrix were upregulated while those associated with fatty acid metabolism were downregulated. We conclude that alterations in cardiomyocytes after ET-1 treatment go far beyond hypertrophy and represent a useful model for diastolic dysfunction. [Display omitted] • ET-1 treatment results in hypertrophy and stiffening of cardiomyocytes. • Severe impairment of relaxation in ET-1 treated cardiomyocytes. • Differential expression of genes involved in cardiovascular diseases under ET-1 treamtent. • ET-1 treated cardiomyocytes model diastolic dysfunction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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29. Sucrose promotes cone enlargement via the TgNGA1‐TgWRKY47‐TgEXPA2 module in Torreya grandis.
- Author
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Suo, Jinwei, Liu, Ya, Yan, Jiawen, Li, Qianxi, Chen, Weijie, Liu, Zhihui, Zhang, Zuying, Hu, Yuanyuan, Yu, Weiwu, Yan, Jingwei, Song, Lili, and Wu, Jiasheng
- Subjects
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TRANSCRIPTION factors , *TOMATOES , *CONES (Botany) , *GENE expression , *CELL size - Abstract
Summary: Cone enlargement is a crucial process for seed production and reproduction in gymnosperms. Most of our knowledge of cone development is derived from observing anatomical structure during gametophyte development. Therefore, the exact molecular mechanism underlying cone enlargement after fertilization is poorly understood. Here, we demonstrate that sucrose promotes cone enlargement in Torreya grandis, a gymnosperm species with relatively low rates of cone enlargement, via the TgNGA1‐TgWRKY47‐TgEXPA2 pathway.Cell expansion plays a significant role in cone enlargement in T. grandis. 13C labeling and sucrose feeding experiments indicated that sucrose‐induced changes in cell size and number contribute to cone enlargement in this species. RNA‐sequencing analysis, transient overexpression in T. grandis cones, and stable overexpression in tomato (Solanum lycopersicum) suggested that the expansin gene TgEXPA2 positively regulates cell expansion in T. grandis cones.The WRKY transcription factor TgWRKY47 directly enhances TgEXPA2 expression by binding to its promoter. Additionally, the NGATHA transcription factor TgNGA1 directly interacts with TgWRKY47. This interaction suppresses the DNA‐binding ability of TgWRKY47, thereby reducing its transcriptional activation on TgEXPA2 without affecting the transactivation ability of TgWRKY47.Our findings establish a link between sucrose and cone enlargement in T. grandis and elucidate the potential underlying molecular mechanism. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Measurement of protein concentration in bacteria and small organelles under a light transmission microscope.
- Author
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Model, M. A., Guo, R., Fasina, K., Jin, R., Clements, R. J., and Leff, L. G.
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LIGHT transmission , *CELL size , *ORGANELLES , *VOLUME measurements , *REFRACTIVE index - Abstract
Protein concentration (PC) is an essential characteristic of cells and organelles; it determines the extent of macromolecular crowding effects and serves as a sensitive indicator of cellular health. A simple and direct way to quantify PC is provided by brightfield‐based transport‐of‐intensity equation (TIE) imaging combined with volume measurements. However, since TIE is based on geometric optics, its applicability to micrometer‐sized particles is not clear. Here, we show that TIE can be used on particles with sizes comparable to the wavelength. At the same time, we introduce a new ImageJ plugin that allows TIE image processing without resorting to advanced mathematical programs. To convert TIE data to PC, knowledge of particle volumes is essential. The volumes of bacteria or other isolated particles can be measured by displacement of an external absorbing dye ("transmission‐through‐dye" or TTD microscopy), and for spherical intracellular particles, volumes can be estimated from their diameters. We illustrate the use of TIE on Escherichia coli, mammalian nucleoli, and nucleolar fibrillar centers. The method is easy to use and achieves high spatial resolution. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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31. Biobased Immiscible Polylactic Acid (PLA): Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) Blends: Impact of Rheological and Non-isothermal Crystallization on the Bead Foaming Behavior.
- Author
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Brütting, Christian, Dreier, Julia, Bonten, Christian, and Ruckdäschel, Holger
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RHEOLOGY ,POLYMER blends ,EXTRUSION process ,CELL size ,CRYSTALLIZATION ,FOAM ,POLYLACTIC acid - Abstract
Nowadays, bead foams are of great interest due to their high lightweight potential. The processing of such foams strongly depends on the crystallization and rheological behavior of the polymers used. By blending polymers, these properties can be tailored to obtain beaded foams with low density, small cell size and high cell density. As a bio-based polymer, PLA is of great interest due to its renewable carbon source. PLA suffers from its low thermal and rheological properties, which can be compensated by using blends. The correlation between the PLA/PHBV ratio and the rheological as well as the crystallization behavior was investigated. The use of PHBV as a minor phase significantly changes the rheological properties and increases the crystallization behavior of PLA. These findings were applied to the foam extrusion process to obtain low density bead foams. Bead foams with densities below 100 kg/m
3 , mean cell sizes below 50 µm and cell densities of 1 × 107 cells/cm3 were obtained. [ABSTRACT FROM AUTHOR]- Published
- 2024
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32. Transcriptomic responses to shifts in light and nitrogen in two congeneric diatom species.
- Author
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Xiao Ma, Zhen Qin, Johnson, Kevin B., Sweat, L. Holly, Sheng Dai, Gang Li, and Chaolun Li
- Subjects
KREBS cycle ,AMINO acid metabolism ,CARBON fixation ,ALGAL blooms ,TRANSCRIPTOMES ,PHAEODACTYLUM tricornutum - Abstract
Light and nitrogen availability are basic requirements for photosynthesis. Changing in light intensity and nitrogen concentration may require adaptive physiological and life process changes in phytoplankton cells. Our previous study demonstrated that two Thalassiosira species exhibited, respectively, distinctive physiological responses to light and nitrogen stresses. Transcriptomic analyses were employed to investigate the mechanisms behind the different physiological responses observed in two diatom species of the genus Thalassiosira. The results indicate that the congeneric species are different in their cellular responses to the same shifting light and nitrogen conditions. When conditions changed to high light with low nitrate (HLLN), the large-celled T. punctigera was photodamaged. Thus, the photosynthesis pathway and carbon fixation related genes were significantly down-regulated. In contrast, the small-celled T. pseudonana sacrificed cellular processes, especially amino acid metabolisms, to overcome the photodamage. When changing to high light with high nitrate (HLHN) conditions, the additional nitrogen appeared to compensate for the photodamage in the large-celled T. punctigera, with the tricarboxylic acid cycle (TCA cycle) and carbon fixation significantly boosted. Consequently, the growth rate of T. punctigera increased, which suggest that the larger-celled species is adapted for forming post-storm algal blooms. The impact of high light stress on the small-celled T. pseudonana was not mitigated by elevated nitrate levels, and photodamage persisted. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
33. Actomyosin-mediated apical constriction promotes physiological germ cell death in C. elegans.
- Author
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Kohlbrenner, Tea, Berger, Simon, Laranjeira, Ana Cristina, Aegerter-Wilmsen, Tinri, Comi, Laura Filomena, deMello, Andrew, and Hajnal, Alex
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- *
CELL size , *CELL death , *CAENORHABDITIS elegans , *ACTOMYOSIN , *OVUM - Abstract
Germ cell apoptosis in Caenorhabditis elegans hermaphrodites is a physiological process eliminating around 60% of all cells in meiotic prophase to maintain tissue homeostasis. In contrast to programmed cell death in the C. elegans soma, the selection of germ cells undergoing apoptosis is stochastic. By live-tracking individual germ cells at the pachytene stage, we found that germ cells smaller than their neighbors are selectively eliminated through apoptosis before differentiating into oocytes. Thus, cell size is a strong predictor of physiological germ cell death. The RAS/MAPK and ECT/RHO/ROCK pathways together regulate germ cell size by controlling actomyosin constriction at the apical rachis bridges, which are cellular openings connecting the syncytial germ cells to a shared cytoplasmic core. Enhancing apical constriction reduces germ cell size and increases the rate of cell death while inhibiting the actomyosin network in the germ cells prevents their death. We propose that actomyosin contractility at the rachis bridges of the syncytial germ cells amplifies intrinsic disparities in cell size. Through this mechanism, the animals can adjust the balance between physiological germ cell death and oocyte differentiation. Germ cell apoptosis in C. elegans hermaphrodites eliminates around 60% of all cells in meiotic prophase to maintain tissue homeostasis. Here, the authors show that the size of meiotic germ cells is reduced by apical actomyosin constriction, which causes cell death to maintain homeostasis in C. elegans germline. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Identification of circulating tumor cells captured by the FDA-cleared Parsortix® PC1 system from the peripheral blood of metastatic breast cancer patients using immunofluorescence and cytopathological evaluations.
- Author
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Ciccioli, Mariacristina, Kim, Kyukwang, Khazan, Negar, Khoury, Joseph D, Cooke, Martin J, Miller, M Craig, O'Shannessy, Daniel J, Pailhes-Jimenez, Anne-Sophie, and Moore, Richard G
- Subjects
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METASTATIC breast cancer , *BREAST biopsy , *CANCER cells , *CELL size , *CANCER patients - Abstract
Circulating Tumor Cells (CTCs) may serve as a non-invasive source of tumor material to investigate an individual's disease in real-time. The Parsortix® PC1 System, the first FDA-cleared medical device for the capture and harvest of CTCs from peripheral blood of metastatic breast cancer (MBC) patients for use in subsequent user-validated downstream analyses, enables the epitope-independent capture of CTCs with diverse phenotypes based on cell size and deformability. The aim of this study was to determine the proportion of MBC patients and self-declared female healthy volunteers (HVs) that had CTCs identified using immunofluorescence (IF) or Wright-Giemsa (WG) staining. Peripheral blood from 76 HVs and 76 MBC patients was processed on Parsortix® PC1 Systems. Harvested cells were cytospun onto a charged slide and immunofluorescently stained for identification of CTCs expressing epithelial markers. The IF slides were subsequently WG-stained and analyzed for CTC identification based on morphological features of malignant cells. All testing was performed by operators blinded to the clinical status of each subject. CTCs were identified on the IF slides in 45.3% (≥ 1) / 24.0% (≥ 5) of the MBC patients (range = 0 – 125, mean = 7) and in 6.9% (≥ 1) / 2.8% (≥ 5) of the HVs (range = 0 – 28, mean = 1). Among the MBC patients with ≥ 1 CTC, 70.6% had only CK + /EpCAM- CTCs, with none having EpCAM + /CK- CTCs. CTC clusters were identified in 56.0% of the CTC-positive patients. On the WG-stained slides, CTCs were identified in 42.9% (≥ 1) / 21.4% (≥ 5) of the MBC patients (range = 0 – 41, mean = 4) and 4.3% (≥ 1) / 2.9% (≥ 5) of the HVs (range = 0 – 14, mean = 0). This study demonstrated the ability of the Parsortix® PC1 System to capture and harvest CTCs from a significantly larger proportion of MBC patients compared to HVs when coupled with both IF and WG cytomorphological assessment. The presence of epithelial cells in subjects without diagnosed disease has been previously described, with their significance being unclear. Interestingly, a high proportion of the identified CTCs did not express EpCAM, highlighting the limitations of using EpCAM-based approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Effects of triploidization on light sensitivity in larval stage of Pacific bluefin tuna Thunnus orientalis.
- Author
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Hayashida, Takao, Higuchi, Kentaro, Okita, Kogen, Takashi, Toshinori, Kazeto, Yukinori, and Gen, Koichiro
- Subjects
- *
FISH larvae , *TUNA , *SENSORY perception , *CELL size , *LARVAE - Abstract
Triploidization influences various biological characteristics of fish, which is associated with reductions in the number of multiple cell types in different tissues/organs. Our behavioral analyses revealed that triploid Pacific bluefin tuna (Thunnus orientalis) larvae exhibit lower sensitivity to light compared to diploids. Furthermore, histological analyses revealed a reduction in the number of ganglion cells and an increase in their size in the retinas of triploid T. orientalis larvae. Our findings provide the first evidence indicating that triploidization reduces sensory perception during the larval stage of fish. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Natural and revolutionary tumor-specific T-cell therapy.
- Author
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Dai, Zhi, Liu, Xue-Meng, Zhao, Yun-li, Zhao, Li-Xing, and Luo, Xiao-Dong
- Subjects
CELL size ,ANTIGEN presenting cells ,TUMOR antigens ,CANCER cells ,CELL separation ,T cells - Abstract
Recently the FDA conducted a risk investigation and labeled the Boxed Warning for all BCMA- and CD19-directed CAR-T cell therapy, so does it mean that the public must take risk of secondary cancer to receive cell therapy? Here, without lentivirus and professional antigen presenting cell application, a novel tumor-specific T-cell therapy was successfully developed only by co-culturing MHC
+ cancer cells and Naïve-T cells under the CD28 co-stimulatory signals. These tumor-specific T-cells could be separated through cell size and abundantly produced from peripheral blood, and would spontaneously attack target cells that carrying the same tumor antigen while avoiding others in vitro test. Moreover, it markedly decreased 90% tumor nodules companying with greatly improving overall survival (76 days vs 30 days) after twice infusion back to mice. This work maximally avoided the risks of secondary cancer and non-specific killing, and might open a revolutionary beginning of natural tumor-specific T-cell therapy. Highlights: Tumor specific T-cell generation without lentivirus and professional APC application. Only by co-culturing MHC+ cancer cell and Naïve-T cell supplying CD28 signal. Easy separation by cell size and fast generation from peripheral blood. Maximally avoid troubles of viral safety and non-specific reaction. Novel model of T-cell activation could be used to bioprospect medicinal molecules instead of CD28 from abundant natural products. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
37. The First Thai Case of Nondeletional HbH Disease Caused by Compound Heterozygosity for α-Thalassemia-1 Chiang Rai (--CR) Type Deletion with Hb Constant Spring.
- Author
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Songdej, Duantida, Kadegasem, Praguywan, Sirachainan, Nongnuch, Ruengdit, Chedtapak, Punyamung, Manoo, and Pornprasert, Sakorn
- Subjects
- *
CAPILLARY electrophoresis , *CELL size , *BLOOD diseases , *HEMOGLOBINOPATHY , *THALASSEMIA - Abstract
AbstractHemoglobin (Hb) H disease presents a wide range of clinical phenotypes, from asymptomatic to severe forms, depending on significant genetic heterogeneity. This is the first report of clinical and hematological features of the nondeletional HbH disease caused by --CR/αCSα. A baby was born to a father and a mother with --CR and αCSα carriers, respectively. She had severe symptomatic hypochromic microcytic anemia at 2 months of age with Hb 7.8 g/dL, packed cell volume (PCV) 0.27 L/L, mean corpuscular volume (MCV) 64.3 fL, and mean corpuscular Hb (MCH) 18.3 pg. The Hb analysis using capillary electrophoresis (CE) showed Hb Bart’s, HbH, and Hb CS peaks at 17.1%, 2.2%, and 1.6%, respectively. A better understanding of a patient’s clinical and hematological features with --CR/αCSα is useful for hemoglobinopathy counseling for the national thalassemia controlling program. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. A systematic scheme to maintain multiple characteristics for effective polygon rasterization.
- Author
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Zhou, Chen and Li, Manchun
- Subjects
- *
CELL size , *POLYGONS , *TOPOLOGY , *ARTIFICIAL intelligence , *PIXELS - Abstract
AbstractPolygon characteristics, including area, shape, and topology, may be lost during rasterization, leading to inaccurate analyses. Maintaining multiple characteristics remains a challenging multi-objective optimization problem. This study introduces improved strategies for flexibly maintaining multiple characteristics (ISMMC). Errors related to area (A), shape (S), and topology (T) are addressed using six prioritized sequences: AST, ATS, TAS, TSA, STA, and SAT, where the order of the letters denotes the sequence of error correction. The importance (I) of land-use types (LUT) is also considered when developing a strategy based on the TSA (ITSA) that maintains characteristics for important LUTs. The ISMMC achieved a total improved accuracy (IA) of ≥0.05 for 98.67% of 150 tested cases. The STA, SAT, TAS, and TSA yielded the highest area, shape, topological, and total accuracies. The STA achieved a summed AI increase ≥20.36% compared to the existing version. The runtime was ≥85.46 times the scanline runtime, and the threshold cell size (≤50 m) balanced the IA and runtime. The ITSA improved accuracy by 83.33% and 6.67% of solutions when preferentially maintaining one or two important LUTs, outperforming the existing STA. Overall, these developments improve accuracy with flexibility in rasterization results and subsequent raster applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Structure, physical and 27Al NMR-spectroscopic properties of the equiatomic compounds of the type <italic>RE</italic>AlRh (<italic>RE</italic> = Sm, Tb, Dy, Er, and Lu)
- Author
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Radzieowski, Mathis, Gießelmann, Elias C. J., Engel, Stefan, and Janka, Oliver
- Subjects
- *
UNIT cell , *NUCLEAR magnetic resonance spectroscopy , *CELL size , *MAGNETIC properties , *CELLULAR evolution - Abstract
Within the series of the equiatomic
RE AlRh compounds, the representatives withRE = Y, La–Nd, Gd, Ho, Tm and Yb have been synthesized. The members withRE = Sm, Tb, Dy, Er and Lu, however, had not yet been reported. They have now been synthesized and structurally as well as magnetically and NMR-spectroscopically characterized. All members crystallize isostructurally in the orthorhombic TiNiSi type, similar to most of the known analogues. The evolution of their unit cell volumes exhibits the expected decrease due to the lanthanide contraction. While LuAlRh shows Pauli-paramagnetic behavior, SmAlRh, TbAlRh, DyAlRh, ErAlRh, and TmAlRh exhibit antiferromagnetic ground states with Néel temperatures betweenT N = 45 and 4 K. 27Al MAS-NMR investigations have been conducted on YAlRh and LuAlRh. The results of quantum-chemical calculations support the conclusions drawn from the NMR-spectroscopic study and give information on the charge distribution in these intermetallic aluminum metallides. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
40. Therapeutic Senolysis of Axitinib-Induced Senescent Human Lung Cancer Cells.
- Author
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Kotani, Hitoshi, Han, Wei, Iida, Yuichi, Tanino, Ryosuke, Katakawa, Kazuaki, Okimoto, Tamio, Tsubata, Yukari, Isobe, Takeshi, and Harada, Mamoru
- Subjects
- *
VASCULAR endothelial growth factors , *BIOLOGICAL models , *ADENOCARCINOMA , *FLOW cytometry , *PHOSPHORYLATION , *RESEARCH funding , *CELLULAR aging , *ANTINEOPLASTIC agents , *PROTEIN-tyrosine kinase inhibitors , *APOPTOSIS , *POLYMERASE chain reaction , *XENOGRAFTS , *DESCRIPTIVE statistics , *CELL lines , *MICE , *GENE expression , *REACTIVE oxygen species , *MESSENGER RNA , *CELL death , *LUNG tumors , *ANIMAL experimentation , *MOLECULAR structure , *CELL size , *LUNG cancer , *GLYCOSIDASES , *CELL receptors , *INTERLEUKINS , *PHARMACODYNAMICS - Abstract
Simple Summary: Tyrosine kinase inhibitors (TKIs) inhibit receptor-mediated signals in cancer and vascular endothelial cells. Especially, axitinib inhibits signaling via vascular endothelial growth factor receptors (VEGFRs). In this study, we report an unforeknown effect of axitinib on human lung cancer cells. We show that axitinib increased the cell size and enhanced the expression of β-galactosidase in a panel of human cancer cell lines, irrespective of their expression of VEGFRs. Especially, axitinib-treated human lung adenocarcinoma A549 cells showed typical senescence and subsequent treatment with the senolytic drug ABT-263 induced drastic cell death (senolysis). Senolysis of senescent A549 cells by ABT-263 was attributed to caspase-dependent apoptosis and Bcl-xL inhibition. Reactive oxygen species were involved in axitinib-induced senescence, but not in senolysis, of A549 cells. In an A549-xenografted mouse model, combination therapy with axitinib and ABT-263 significantly suppressed tumor growth. Background: Tyrosine kinase inhibitors (TKIs) inhibit receptor-mediated signals in cells. Axitinib is a TKI with high specificity for vascular endothelial growth factor receptors (VEGFRs). Aim: We determined whether axitinib could induce senescence in human cancer cells and be lysed by the senolytic drug ABT-263. Methods: Human lung and breast adenocarcinoma cell lines were used. These cells were cultured with axitinib or a multi-target TKI lenvatinib. The expression of β-galactosidase, VEGFRs, Ki-67, reactive oxygen species (ROS) of cancer cells, and their BrdU uptake were evaluated by flow cytometry. The mRNA expression of p21 and IL-8 was examined by quantitative PCR. The effects of TKIs on phosphorylation of Akt and Erk1/2, as downstream molecules of VEGFR signaling, were examined by immunoblot. The in vivo anti-cancer effect was examined using a xenograft mice model. Results: Axitinib, but not lenvatinib, induced cellular senescence (increased cell size and enhanced expression of β-galactosidase) in all adenocarcinoma cell lines. Axitinib-induced senescence was unrelated to the expression of VEGFRs on cancer cells. ROS were involved in axitinib-induced senescence. Axitinib-induced senescent lung adenocarcinoma A549 cells were drastically lysed by ABT-263. In A549-xenografted mice, combination therapy with axitinib and ABT-263 significantly suppressed tumor growth with the induction of apoptotic cancer cells. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Length control emerges from cytoskeletal network geometry.
- Author
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McInally, Shane G., Reading, Alexander J. B., Rosario, Aldric, Jelenkovic, Predrag R., Goode, Bruce L., and Kondev, Jane
- Subjects
- *
CELL imaging , *CELL size , *FIBERS , *ACTIN , *CYTOSKELETON - Abstract
Many cytoskeletal networks consist of individual filaments that are organized into elaborate higher-order structures. While it is appreciated that the size and architecture of these networks are critical for their biological functions, much of the work investigating control over their assembly has focused on mechanisms that regulate the turnover of individual filaments through size-dependent feedback. Here, we propose a very different, feedback-independent mechanism to explain how yeast cells control the length of their actin cables. Our findings, supported by quantitative cell imaging and mathematical modeling, indicate that actin cable length control is an emergent property that arises from the cross-linked and bundled organization of the filaments within the cable. Using this model, we further dissect the mechanisms that allow cables to grow longer in larger cells and propose that cell length-dependent tuning of formin activity allows cells to scale cable length with cell length. This mechanism is a significant departure from prior models of cytoskeletal filament length control and presents a different paradigm to consider how cells control the size, shape, and dynamics of higher-order cytoskeletal structures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Meflin/ISLR is a marker of adipose stem and progenitor cells in mice and humans that suppresses white adipose tissue remodeling and fibrosis.
- Author
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Ishihara, Toshikazu, Kato, Katsuhiro, Matsumoto, Kotaro, Tanaka, Miyako, Hara, Akitoshi, Shiraki, Yukihiro, Morisaki, Hidenori, Urano, Yuya, Ando, Ryota, Ito, Kisuke, Mii, Shinji, Esaki, Nobutoshi, Furuhashi, Kazuhiro, Takefuji, Mikito, Suganami, Takayoshi, Murohara, Toyoaki, and Enomoto, Atsushi
- Subjects
- *
WHITE adipose tissue , *PROGENITOR cells , *CELL size , *STEM cells , *MESENCHYMAL stem cells , *FAT cells - Abstract
Identifying specific markers of adipose stem and progenitor cells (ASPCs) in vivo is crucial for understanding the biology of white adipose tissues (WAT). PDGFRα‐positive perivascular stromal cells represent the best candidates for ASPCs. This cell lineage differentiates into myofibroblasts that contribute to the impairment of WAT function. However, ASPC marker protein(s) that are functionally crucial for maintaining WAT homeostasis are unknown. We previously identified Meflin as a marker of mesenchymal stem cells (MSCs) in bone marrow and tissue‐resident perivascular fibroblasts in various tissues. We also demonstrated that Meflin maintains the undifferentiated status of MSCs/fibroblasts. Here, we show that Meflin is expressed in WAT ASPCs. A lineage‐tracing experiment showed that Meflin+ ASPCs proliferate in the WAT of obese mice induced by a high‐fat diet (HFD), while some of them differentiate into myofibroblasts or mature adipocytes. Meflin knockout mice fed an HFD exhibited a significant fibrotic response as well as increases in adipocyte cell size and the number of crown‐like structures in WAT, accompanied by impaired glucose tolerance. These data suggested that Meflin expressed by ASPCs may have a role in reducing disease progression associated with WAT dysfunction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Enhancing [177Lu]Lu-DOTA-TATE therapeutic efficacy in vitro by combining it with metronomic chemotherapeutics.
- Author
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Cheng, Jordan, Zink, Joke, O'Neill, Edward, Cornelissen, Bart, Nonnekens, Julie, Livieratos, Lefteris, and Terry, Samantha Y. A.
- Subjects
- *
CELL size , *PEPTIDE receptors , *CELL cycle , *NEUROENDOCRINE tumors , *CELL survival - Abstract
Background: Peptide receptor radionuclide therapy (PRRT) uses [177Lu]Lu-[DOTA0-Tyr3]octreotate ([177Lu]Lu-DOTA-TATE) to treat patients with neuroendocrine tumours (NETs) overexpressing the somatostatin receptor 2A (SSTR2A). It has shown significant short-term improvements in survival and symptom alleviation, but there remains room for improvement. Here, we investigated whether combining [177Lu]Lu-DOTA-TATE with chemotherapeutics enhanced the in vitro therapeutic efficacy of [177Lu]Lu-DOTA-TATE. Results: Transfected human osteosarcoma (U2OS + SSTR2A, high SSTR2A expression) and pancreatic NET (BON1 + STTR2A, medium SSTR2A expression) cells were subjected to hydroxyurea, gemcitabine or triapine for 24 h at 37oC and 5% CO2. Cells were then recovered for 4 h prior to a 24-hour incubation with 0.7–1.03 MBq [177Lu]Lu-DOTA-TATE (25 nM) for uptake and metabolic viability studies. Incubation of U2OS + SSTR2A cells with hydroxyurea, gemcitabine, and triapine enhanced uptake of [177Lu]Lu-DOTA-TATE from 0.2 ± 0.1 in untreated cells to 0.4 ± 0.1, 1.1 ± 0.2, and 0.9 ± 0.2 Bq/cell in U2OS + SSTR2A cells, respectively. Cell viability post treatment with [177Lu]Lu-DOTA-TATE in cells pre-treated with chemotherapeutics was decreased compared to cells treated with [177Lu]Lu-DOTA-TATE monotherapy. For example, the viability of U2OS + SSTR2A cells incubated with [177Lu]Lu-DOTA-TATE decreased from 59.5 ± 22.3% to 18.8 ± 5.2% when pre-treated with hydroxyurea. Control conditions showed no reduced metabolic viability. Cells were also harvested to assess cell cycle progression, SSTR2A expression, and cell size by flow cytometry. Chemotherapeutics increased SSTR2A expression and cell size in U2OS + SSTR2A and BON1 + STTR2A cells. The S-phase sub-population of asynchronous U2OS + SSTR2A cell cultures was increased from 45.5 ± 3.3% to 84.8 ± 2.5%, 85.9 ± 1.9%, and 86.6 ± 2.2% when treated with hydroxyurea, gemcitabine, and triapine, respectively. Conclusions: Hydroxyurea, gemcitabine and triapine all increased cell size, SSTR2A expression, and [177Lu]Lu-DOTA-TATE uptake, whilst reducing cell metabolic viability in U2OS + SSTR2A cells when compared to [177Lu]Lu-DOTA-TATE monotherapy. Further investigations could transform patient care and positively increase outcomes for patients treated with [177Lu]Lu-DOTA-TATE. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Substrate availability may limit the response of tropical bacterioplankton biomass to warming.
- Author
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Morán, Xosé Anxelu G., Calleja, Maria Ll., Baltar, Federico, Silva, Luis, Ansari, Mohd Ikram, Albornoz, Paloma Carrillo, Duarte, Carlos M., and Lønborg, Christian
- Subjects
- *
HETEROTROPHIC bacteria , *BIOTIC communities , *BACTERIAL communities , *CELL size , *MANGROVE plants , *SEAGRASSES , *DISSOLVED organic matter , *SEAGRASS restoration - Abstract
The response of heterotrophic bacterioplankton to the addition of macrophytic dissolved organic matter (DOM) and temperature was investigated in the Red Sea. We added 40 μmol C L−1 of leachates obtained from seagrass and mangrove leaves to natural bacterial communities, incubated them at three temperatures (25.5°C found in situ plus 3°C below and above that value) and monitored the microbial and biogeochemical responses over 4 d. Seagrass and mangrove DOM, important allochthonous sources in tropical oligotrophic regions, had distinct chemical characteristics compared to unamended seawater, with mangrove substrates containing comparatively more nitrogen and protein‐like fluorescent DOM than seagrass. Specific growth rates (μ) increased twofold in the seagrass and mangrove treatments (1.0 and 0.8 d−1, respectively) relative to the seawater control (0.4 d−1). The biomass of heterotrophic bacteria generally reflected μ changes, reaching maximum values of 16.8 and 17.3 μg C L−1 in the seagrass and mangrove treatments, respectively, compared to just 2.6 μg C L−1 in seawater. The increase in μ values due to experimental warming followed the metabolic theory of ecology, mostly because of enhanced exoenzymatic activity, while cell size decreased as predicted by the temperature–size rule (mean −3% per °C increase). Although the labile nature of the specific seagrass and mangrove DOM leachates was clearly demonstrated, we conclude that tropical heterotrophic bacteria may have limited capability to increase their biomass as a consequence of future warming, even in the presence of high loadings of macrophytic DOM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Diatom abundance in the polar oceans is predicted by genome size.
- Author
-
Roberts, Wade R., Siepielski, Adam M., and Alverson, Andrew J.
- Subjects
- *
GENOME size , *BODY size , *CARBON fixation , *CELL size ,COLD regions - Abstract
A principal goal in ecology is to identify the determinants of species abundances in nature. Body size has emerged as a fundamental and repeatable predictor of abundance, with smaller organisms occurring in greater numbers than larger ones. A biogeographic component, known as Bergmann's rule, describes the preponderance, across taxonomic groups, of larger-bodied organisms in colder areas. Although undeniably important, the extent to which body size is the key trait underlying these patterns is unclear. We explored these questions in diatoms, unicellular algae of global importance for their roles in carbon fixation and energy flow through marine food webs. Using a phylogenomic dataset from a single lineage with worldwide distribution, we found that body size (cell volume) was strongly correlated with genome size, which varied by 50-fold across species and was driven by differences in the amount of repetitive DNA. However, directional models identified temperature and genome size, not cell size, as having the greatest influence on maximum population growth rate. A global metabarcoding dataset further identified genome size as a strong predictor of species abundance in the ocean, but only in colder regions at high and low latitudes where diatoms with large genomes dominated, a pattern consistent with Bergmann's rule. Although species abundances are shaped by myriad interacting abiotic and biotic factors, genome size alone was a remarkably strong predictor of abundance. Taken together, these results highlight the cascading cellular and ecological consequences of macroevolutionary changes in an emergent trait, genome size, one of the most fundamental and irreducible properties of an organism. Body size is a fundamental predictor of organismal abundance, and larger-bodied organisms predominate in colder areas ("Bergmann's rule"). This study of diatoms reveals that in these unicellular organisms, genome size, rather than cell size, is a strong predictor of species abundance in the polar oceans. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. The effects of drone transportation on blood component quality: A prospective randomised controlled laboratory study.
- Author
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Wiltshire, Michael, Boxshall, Jonathan, Milne, James, Oleniacz, Katarzyna, Theobald, Katherine, and Phillips, Benedict
- Subjects
- *
ERYTHROCYTES , *CELL size , *CELL anatomy , *BLOOD transfusion , *HEMOGLOBINS - Abstract
Summary The use of uncrewed aerial vehicles (drones) has increased over the last decade. However, their application in healthcare has not been fully examined, in part, due to regulations preventing flight beyond the visual line of sight. This prospective randomised controlled laboratory study aimed to determine whether the in vitro quality of packed red blood cell components is maintained when transported by drone, beyond visual line of sight. Ten identical pairs of packed red blood cell units were randomly allocated to transport by drone or by ground vehicle (1:1, allocation concealment) 68 km between two hospitals in Northumbria, UK. Markers of blood component quality were compared at 8, 14, 28 and 35 days following blood unit manufacture. There was no statistical difference in haemolysis, potassium concentration, total haemoglobin, glucose and lactate, haematocrit and mean cell volume, between the two groups, up to the date of unit expiry. The temperature of the packed red blood cell units did not deviate outside the recommended 2–10°C for transportation, regardless of the allocated group. Blood component transport was faster by drone, but did not reach statistical significance. This study demonstrates the feasibility and safety of flying blood components by drone between hospitals in the United Kingdom. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Tuning the Topography of Non‐Wetting Surfaces to Reduce Short‐Term Microbial Contamination Within Hospitals.
- Author
-
van den Berg, Desmond, Asker, Dalal, Kim, Jungchul, Kim, Ho‐Young, Aizenberg, Joanna, and Hatton, Benjamin
- Subjects
- *
INFECTIOUS disease transmission , *MICROBIAL contamination , *BACTERIAL adhesion , *CELL size , *SURFACE topography - Abstract
Microbial contamination of hospital surfaces is a major contributor to infectious disease transmission. This work demonstrates that superhydrophobic (Cassie‐Baxter) micro post topographies can significantly reduce cell attachment compared to flat controls. For ordered micro post arrays (post diameters 0.3 to 150 µm), the attachment of four pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Candida albicans) from discrete contaminant droplets upon short‐term contact (15 s to 30 min) are assessed. There is a 3‐4‐log decrease in microbial attachment when reducing the micro posts diameters from 150 to 0.3 µm for all strains, with large posts (>20 µm) exhibiting similar attachment rates to flat controls. The critical, maximum feature size to prevent attachment can be tuned depending on the ratio of the cell size to post diameter. Two potential mechanisms are discussed for this size effect. First, application of the random sequential adsorption model shows that this relative post/cell size effect may be due to a reduced probability of attachment, which is theorized to be the dominant mechanism. Alternatively, a physical model is suggested for bacterial cell "pull‐off" due to surface tension forces during droplet dewetting. This work may be important for the design of non‐wetting antimicrobial surfaces within healthcare environments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Enhanced phagocytosis associated with multinucleated microglia via Pyk2 inhibition in an acute β-amyloid infusion model.
- Author
-
Lee, Ji-Won, Mizuno, Kaito, Watanabe, Haruhisa, Lee, In-Hee, Tsumita, Takuya, Hida, Kyoko, Yawaka, Yasutaka, Kitagawa, Yoshimasa, Hasebe, Akira, Iimura, Tadahiro, and Kong, Sek Won
- Subjects
- *
PROTEIN-tyrosine kinases , *CELL size , *ALZHEIMER'S disease , *AMYLOID plaque , *GENETIC transcription - Abstract
Multinucleated microglia have been observed in contexts associated with infection, inflammation, and aging. Though commonly linked to pathological conditions, the larger cell size of multinucleated microglia might enhance their phagocytic functions, potentially aiding in the clearance of brain debris and suggesting a reassessment of their pathological significance. To assess the phagocytic capacity of multinucleated microglia and its implications for brain debris clearance, we induced their formation by inhibiting Pyk2 activity using the pharmacological inhibitor PF-431396, which triggers cytokinesis regression. Multinucleated microglia demonstrate enhanced phagocytic function, as evidenced by their increased capacity to engulf β-amyloid (Aβ) oligomers. Concurrently, the phosphorylation of Pyk2, induced by Aβ peptide, was diminished upon treatment with a Pyk2 inhibitor (Pyk2-Inh, PF-431396). Furthermore, the increased expression of Lamp1, a lysosomal marker, with Pyk2-inh treatment, suggests an enhancement in proteolytic activity. In vivo, we generated an acute Alzheimer's disease (AD) model by infusing Aβ into the brains of Iba-1 EGFP transgenic (Tg) mice. The administration of the Pyk2-Inh led to an increased migration of microglia toward amyloid deposits in the brains of Iba-1 EGFP Tg mice, accompanied by morphological activation, suggesting a heightened affinity for Aβ. In human microglia, lipopolysaccharide (LPS)-induced inflammatory responses showed that inhibition of Pyk2 signaling significantly reduced the transcription and protein expression of pro-inflammatory markers. These results suggest that Pyk2 inhibition can modulate microglial functions, potentially reducing neuroinflammation and aiding in the clearance of neurodegenerative disease markers. This highlights Pyk2 as a promising target for therapeutic intervention in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Effect of electrical muscle stimulation on the improvement of deltoid muscle atrophy in a rat shoulder immobilization model.
- Author
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Lee, Jeongkun, Lee, Su Hyun, Kim, Hyuntae, and Chung, Seok Won
- Subjects
- *
ELECTRIC stimulation , *MUSCULAR atrophy , *DELTOID muscles , *SOLUTION strengthening , *CELL size - Abstract
Immobilization following trauma or surgery induces skeletal muscle atrophy, and improvement in the muscle atrophy is critical for successful clinical outcomes. The purpose of this study is to evaluate the effect of electrical muscle stimulation (EMS) on muscle atrophy. The study design is a controlled laboratory study. Eighty rats (56 to establish the deltoid muscle atrophy [DMA] model and 24 to evaluate the effect of EMS on the model) were used. DMA was induced by completely immobilizing the right shoulder of each rat by placing sutures between the scapula and humeral shaft, with the left shoulder as a control. After establishing the DMA model, rats were randomly assigned into three groups: low‐frequency EMS (L‐EMS, 10 Hz frequency), medium‐frequency EMS (M‐EMS, 50 Hz frequency), and control (eight rats per group). After 3 weeks, the deltoid muscles of each rat were harvested, alterations in gene expression and muscle cell size were evaluated, and immunohistochemical analysis was performed. DMA was most prominent 3 weeks after shoulder immobilization. Murf1 and Atrogin were significantly induced at the initial phase and gradually decreased at approximately 3 weeks; however, MyoD expressed an inverse relationship with Murf1 and Atrogin. IL6 expression was prominent at 1 week. The time point for the EMS effect evaluation was selected at 3 weeks, when the DMA was the most prominent with a change in relevant gene expression. The M‐EMS group cell size was significantly larger than that of L‐EMS and control group in both the immobilized and intact shoulders (all
p < 0.05), without significant differences between the L‐EMS and control groups. The M‐EMS group showed significantly lower mRNA expressions of Murf1 and Atrogin and higher expressions of MyoD and Col1A1 than that of the control group (allp < 0.05). In immunohistochemical analysis, similar results were observed with lower Atrogin staining and higher MyoD and Col1A1 staining in the M‐EMS group. DMA model was established by complete shoulder immobilization, with the most prominent muscle atrophy observed at 3 weeks. M‐EMS improved DMA with changes in the expression of relevant genes. M‐EMS might be a solution for strengthening atrophied skeletal muscles and facilitating rehabilitation after trauma or surgery. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
50. Cell growth and nutrient availability control the mitotic exit signaling network in budding yeast.
- Author
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Talavera, Rafael A., Prichard, Beth E., Sommer, Robert A., Leitao, Ricardo M., Sarabia, Christopher J., Hazir, Semin, Paulo, Joao A., Gygi, Steven P., and Kellogg, Douglas R.
- Subjects
- *
CELL growth , *CELL size , *CELL cycle , *YEAST , *NUCLEAR membranes , *BUDS - Abstract
Cell growth is required for cell cycle progression. The amount of growth required for cell cycle progression is reduced in poor nutrients, which leads to a reduction in cell size. In budding yeast, nutrients can influence cell size by modulating the extent of bud growth, which occurs predominantly in mitosis. However, the mechanisms are unknown. Here, we used mass spectrometry to identify proteins that modulate bud growth in response to nutrient availability. This led to the discovery that nutrients regulate numerous components of the mitotic exit network (MEN), which controls exit from mitosis. A key component of the MEN undergoes gradual multisite phosphorylation during bud growth that is dependent upon bud growth and correlated with the extent of growth. Furthermore, activation of the MEN is sufficient to override a growth requirement for mitotic exit. The data suggest a model in which the MEN ensures that mitotic exit occurs only when an appropriate amount of bud growth has occurred. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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