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The theme of the 2022 symposium was 'Cell Diversity in the Cardiovascular System, cell-autonomous and cell-cell signalling'. Keywords: cardiovascular physiology; cell diversity; ion channels; vascular smooth muscle EN cardiovascular physiology cell diversity ion channels vascular smooth muscle 2543 2544 2 07/04/23 20230701 NES 230701 This paper is based on the most recent UC Davis Cardiovascular Research Symposium on Systems Approach to Understanding Cardiovascular Disease and Arrhythmia. Cardiovascular physiology, ion channels, vascular smooth muscle, cell diversity. [Extracted from the article]

The efficiency of antimony selenide (Sb2Se3) solar cells is still limited by significant interface and deep‐level defects, in addition to carrier recombination at the back contact surface. This paper investigates the use of lithium (Li) ions as dopant for Sb2Se3 films, using lithium hydroxide (LiOH) as a dopant medium. Surprisingly, the LiOH solution not only reacts at the back surface of the Sb2Se3 film but also penetrate inside the film along the (Sb4Se6)n molecular chain. First, the Li ions modify the grain boundary's carrier type and create an electric field between p‐type grain interiors and n‐type grain boundary. Second, a gradient band structure is formed along the vertical direction with the diffusion of Li ions. Third, carrier collection and transport are improved at the surface between Sb2Se3 and the Au layer due to the reaction between the film and alkaline solution. Additionally, the diffusion of Li ions increases the crystallinity, orientation, surface evenness, and optical electricity. Ultimately, the efficiency of Sb2Se3 solar cells is improved to 7.57% due to the enhanced carrier extraction, transport, and collection, as well as the reduction of carrier recombination and deep defect density. This efficiency is also a record for CdS/Sb2Se3 solar cells fabricated by rapid thermal evaporation. [ABSTRACT FROM AUTHOR]

Acute pancreatitis (AP) is one of the life‐threatening diseases of the digestive system. MicroRNA has been asserted to be a regulator of AP. This paper explored the miR‐374a‐5p expression in AP patients and investigated the efficacy of AR42J cells. In this study, 60 healthy people, 58 MAP patients and 58 SAP patients were included, and the serum miR‐374a‐5p levels of the subjects were detected by RT‐qPCR technology. The pancreatitis cell model was structured by stimulating AR42J cells with cerulein. Next, cell viability and apoptosis were detected by CCK‐8 assay and flow cytometry. ELISA was used to measure the concentration of cytokines, such as TNF‐α, IL‐6, and IL‐1β. The data showed that miR‐374a‐5p was downregulated in samples from AP patients, while showing discriminative power for AP populations. Attenuated miR‐374a‐5p were negatively bound up with patients' Ranson score and APACHE II score. Besides, miR‐374a‐5p was declined in cerulein‐treated AR42J cells and forced elevation of miR‐374a‐5p was beneficial to increase cell viability, and inhibit cell apoptosis and inflammation. The present study found that miR‐374a‐5p was reduced in AP serum samples, and up‐regulated expression level of miR‐374a‐5p in cell models had a protective effect on cerulein‐induced inhibition of cell function and inflammatory response. [ABSTRACT FROM AUTHOR]

CDC42 is a member of the Rho‐GTPase family and is involved in a variety of cellular functions including regulation of cell cycle progression, constitution of the actin backbone and membrane transport. In particular, CDC42 plays a key role in the establishment of polarity in female vertebrate oocytes, and essential to this major regulatory role is its local occupation of specific regions of the cell to ensure that the contractile ring is assembled at the right time and place to ensure proper gametogenesis. The multifactor controlled 'inactivation‐activation' process of CDC42 also allows it to play an important role in the multilevel signalling network, and the synergistic regulation of multiple genes ensures maximum precision during gametogenesis. The purpose of this paper is to review the role of CDC42 in the control of gametogenesis and to explore its related mechanisms, with the aim of further understanding the great research potential of CDC42 in female vertebrate germ cells and its future clinical translation. [ABSTRACT FROM AUTHOR]

In vitro gametogenesis (IVG) might offer numerous research and clinical benefits. Some potential clinical applications of IVG, such as allowing opposite‐sex couples experiencing infertility to have genetically related children, have attracted support. Others, such as enabling same‐sex reproduction and solo reproduction, have attracted significantly more criticism. In this paper, we examine how different ethical principles might help us to draw lines and distinguish between ethically desirable and undesirable uses of IVG. We discuss the alleged distinction between therapeutic and non‐therapeutic uses of assisted reproduction in the context of IVG, and show how it is both problematic to apply in practice and theoretically dubious. We then discuss how the ethical principles of reproductive justice and beneficence apply to IVG for opposite‐sex reproduction, same‐sex reproduction, and solo reproduction. We suggest that these principles generate strong reasons for the use of IVG for opposite‐sex and same‐sex reproduction, but not for solo reproduction. [ABSTRACT FROM AUTHOR]

In multicellular organisms, stem cells are impacted by microenvironmental resources such as nutrient availability and oxygen tension for their survival, growth, and differentiation. However, the accessibility of these resources in the pericellular environment greatly varies from organ to organ. This divergence in resource availability leads to variations in the potency and differentiation potential of stem cells. This study aimed to explore the distinct effects of glucose and fructose, as well as different oxygen tensions, on the growth dynamics, cytokine production, and differentiation of stem cells. We showed that replacing glucose with fructose subjected stem cells to stress, resulting in increased Hif1α expression and stability, which in turn led to a reduction in cell proliferation, and alterations in cytokine production. However, fructose failed to induce differentiation of human mesenchymal stem cells (hMSCs) as well as mouse fibroblasts into mature adipocytes compared to glucose, despite the upregulation of key markers of adipogenesis, including C/EBPβ, and PPARγ. Conversely, we showed that fructose induced undifferentiated mouse fibroblasts to release cytokines associated with senescence, including IL1α1, IL6, IL8, MCP1, and TNF1α, suggesting that these cells were undergoing lipolysis. Taken together, our results suggest that altering the culture conditions through changes in hexose levels and oxygen tension places considerable stress on stem cells. Additional research is required to further characterize the mechanisms governing stem cell response to their microenvironments. [ABSTRACT FROM AUTHOR]

Adapted immune cells are known to develop memory functions that increase resistance to subsequent infections after initial pathogen exposure, however, it is unclear whether non‐immune cells, like tissue‐resident stem cells, have similar memory functions. Here, it is found that tissue‐resident stem cells crucial for tissue regeneration show diminished adverse effects on diverse stem cell functions against successive exposure to foreign antigen (β‐glucan) to maintain tissue homeostasis and stability both in vitro and in vivo. These data suggest that endometrial stem cells may possess a robust memory function, in contrast, fully differentiated cells like fibroblasts and vesicular cells do not show these memory mechanisms upon consecutive antigen exposure. Moreover, the pivotal role of Angiopoietin‐like 4 (ANGPTL4) in regulating the memory functions of endometrial stem cells is identified through specific shRNA knockdown in vitro and knockout mice in vivo experiments. ANGPTL4 is associated with the alteration of diverse stem cell functions and epigenetic modifications, notably through histone H3 methylation changes and two pathways (i.e., PI3K/Akt and FAK/ERK1/2 signaling) upon consecutive antigen exposure. These findings imply the existence of inherent self‐defense mechanisms through which local stem cells can adapt and protect themselves from recurrent antigenic challenges, ultimately mitigating adverse consequences. [ABSTRACT FROM AUTHOR]

Objective: Unique metabolic requirements accompany the development and functional fates of immune cells. How cellular metabolism is important in natural killer (NK) cells and their memory‐like differentiation in bacterial infections remains elusive. Methods: Here, we utilise our established NK cell memory assay to investigate the metabolic requirement for memory‐like NK cell formation and function in response to the Gram‐negative intracellular bacteria Burkholderia pseudomallei (BP), the causative agent of melioidosis. Results: We demonstrate that CD160+ memory‐like NK cells upon BP stimulation upregulate glucose and amino acid transporters in a cohort of recovered melioidosis patients which is maintained at least 3‐month post‐hospital admission. Using an in vitro assay, human BP‐specific CD160+ memory‐like NK cells show metabolic priming including increased expression of glucose and amino acid transporters with elevated glucose uptake, increased mTOR activation and mitochondrial membrane potential upon BP re‐stimulation. Antigen‐specific and cytokine‐induced IFN‐γ production of this memory‐like NK cell subset are highly dependent on oxidative phosphorylation (OXPHOS) with some dependency on glycolysis, whereas the formation of CD160+ memory‐like NK cells in vitro is dependent on fatty acid oxidation and OXPHOS and further increased by metformin. Conclusion: This study reveals the link between metabolism and cellular function of memory‐like NK cells, which can be exploited for vaccine design and for monitoring protection against Gram‐negative bacterial infection. [ABSTRACT FROM AUTHOR]

Nuclear receptor coactive 4 (NCOA4), which functions as a selective cargo receptor, is a critical regulator of the particularly autophagic degradation of ferritin, a process known as ferritinophagy. Mechanistically, NCOA4‐mediated ferritinophagy performs an increasingly vital role in the maintenance of intracellular iron homeostasis by promoting ferritin transport and iron release as needed. Ferritinophagy is not only involved in iron‐dependent responses but also in the pathogenesis and progression of various human diseases, including metabolism‐related, neurodegenerative, cardiovascular and infectious diseases. Therefore, ferritinophagy is of great importance in maintaining cell viability and function and represents a potential therapeutic target. Recent studies indicated that ferritinophagy regulates the signalling pathway associated with ferroptosis, a newly discovered type of cell death characterised by iron‐dependent lipid peroxidation. Although accumulating evidence clearly demonstrates the importance of the interplay between dysfunction in iron metabolism and ferroptosis, a deeper understanding of the double‐edged sword effect of ferritinophagy in ferroptosis has remained elusive. Details of the mechanisms underlying the ferritinophagy–ferroptosis axis in regulating relevant human diseases remain to be elucidated. In this review, we discuss the latest research findings regarding the mechanisms that regulate the biological function of NCOA4‐mediated ferritinophagy and its contribution to the pathophysiology of ferroptosis. The important role of the ferritinophagy–ferroptosis axis in human diseases will be discussed in detail, highlighting the great potential of targeting ferritinophagy in the treatment of diseases. [ABSTRACT FROM AUTHOR]

Autophagy is a self‐recycling machinery to maintain cellular homeostasis by degrading harmful materials in the cell. Autophagy‐related gene 5 (Atg5) is required for autophagosome maturation. However, the role of Atg5 in tumorigenesis under autophagy deficient conditions remains unclear. This study focused on the autophagy‐independent role of Atg5 and the underlying mechanism in tumorigenesis. We demonstrated that knockout of autophagy‐related genes including Atg5, Atg7, Atg9, and p62 in mouse embryonic fibroblast (MEF) cells consistently decreased cell proliferation and motility, implying that autophagy is required to maintain diverse cellular functions. An Atg7 knockout MEF (Atg7−/− MEF) cell line representing deprivation of autophagy function was used to clarify the role of Atg5 transgene in tumorigenesis. We found that Atg5‐overexpressed Atg7−/‐MEF (clone A) showed increased cell proliferation, colony formation, and migration under autophagy deficient conditions. Accordingly, rescuing the autophagy deficiency of clone A by overexpression of Atg7 gene shifts the role of Atg5 from pro‐tumor to anti‐tumor status, indicating the dual role of Atg5 in tumorigenesis. Notably, the xenograft mouse model showed that clone A of Atg5‐overexpressed Atg7−/− MEF cells induced temporal tumor formation, but could not prolong further tumor growth. Finally, biomechanical analysis disclosed increased Wnt5a secretion and p‐JNK expression along with decreased β‐catenin expression. In summary, Atg5 functions as a tumor suppressor to protect the cell under normal conditions. In contrast, Atg5 shifts to a pro‐tumor status under autophagy deprivation conditions. [ABSTRACT FROM AUTHOR]

The physical interactome of a protein can be altered upon perturbation, modulating cell physiology and contributing to disease. Identifying interactome differences of normal and disease states of proteins could help understand disease mechanisms, but current methods do not pinpoint structure-specific PPIs and interaction interfaces proteome-wide. We used limited proteolysis–mass spectrometry (LiP–MS) to screen for structure-specific PPIs by probing for protease susceptibility changes of proteins in cellular extracts upon treatment with specific structural states of a protein. We first demonstrated that LiP–MS detects well-characterized PPIs, including antibody–target protein interactions and interactions with membrane proteins, and that it pinpoints interfaces, including epitopes. We then applied the approach to study conformation-specific interactors of the Parkinson's disease hallmark protein alpha-synuclein (aSyn). We identified known interactors of aSyn monomer and amyloid fibrils and provide a resource of novel putative conformation-specific aSyn interactors for validation in further studies. We also used our approach on GDP- and GTP-bound forms of two Rab GTPases, showing detection of differential candidate interactors of conformationally similar proteins. This approach is applicable to screen for structure-specific interactomes of any protein, including posttranslationally modified and unmodified, or metabolite-bound and unbound protein states. Synopsis: A structural proteomics approach for identifying candidate interactors of any protein within a complex lysate is presented. It is applied to identify conformation-specific interactors of Rab GTPases and of the monomeric and fibrillar forms of the disease-associated protein alpha-synuclein. A method is presented for identifying candidate interactors of any bait protein within a complex lysate. It is applicable to the identification of conformation-specific interactors and pinpoints interaction sites. A resource of candidate interactors of monomeric and fibrillar forms of alpha-synuclein is presented. Candidate interactors of GTP- and GDP-bound forms of Rab GTPases are identified. A structural proteomics approach for identifying candidate interactors of any protein within a complex lysate is presented. It is applied to identify conformation-specific interactors of Rab GTPases and of the monomeric and fibrillar forms of the disease-associated protein alpha-synuclein. [ABSTRACT FROM AUTHOR]

Dysregulated RNA modifications, stemming from the aberrant expression and/or malfunction of RNA modification regulators operating through various pathways, play pivotal roles in driving the progression of haematological malignancies. Among RNA modifications, N6‐methyladenosine (m6A) RNA modification, the most abundant internal mRNA modification, stands out as the most extensively studied modification. This prominence underscores the crucial role of the layer of epitranscriptomic regulation in controlling haematopoietic cell fate and therefore the development of haematological malignancies. Additionally, other RNA modifications (non‐m6A RNA modifications) have gained increasing attention for their essential roles in haematological malignancies. Although the roles of the m6A modification machinery in haematopoietic malignancies have been well reviewed thus far, such reviews are lacking for non‐m6A RNA modifications. In this review, we mainly focus on the roles and implications of non‐m6A RNA modifications, including N4‐acetylcytidine, pseudouridylation, 5‐methylcytosine, adenosine to inosine editing, 2′‐O‐methylation, N1‐methyladenosine and N7‐methylguanosine in haematopoietic malignancies. We summarise the regulatory enzymes and cellular functions of non‐m6A RNA modifications, followed by the discussions of the recent studies on the biological roles and underlying mechanisms of non‐m6A RNA modifications in haematological malignancies. We also highlight the potential of therapeutically targeting dysregulated non‐m6A modifiers in blood cancer. [ABSTRACT FROM AUTHOR]

High‐resolution spatio‐temporal monitoring of the cell membrane lipid order provides visual insights into the complex and sophisticated systems that control cellular physiological functions. Solvatochromic fluorescent probes are highly promising noninvasive visualization tools for identifying the ordering of the microenvironment of plasma membrane microdomains. However, conventional probes, although capable of structural analysis, lack the necessary long‐term photostability required for live imaging at the cellular level. Here, an ultra‐high‐light‐resistant solvatochromic fluorescence probe, 2‐N,N‐diethylamino‐7‐(4‐methoxycarbonylphenyl)‐9,9‐dimethylfluorene (FπCM) is reported, which enables live lipid order imaging of cell division. This probe and its derivatives exhibit sufficient fluorescence wavelengths, brightness, polarity responsiveness, low phototoxicity, and remarkable photostability under physiological conditions compared to conventional solvatochromic probes. Therefore, these probes have the potential to overcome the limitations of fluorescence microscopy, particularly those associated with photobleaching. FπCM probes can serve as valuable tools for elucidating mechanisms of cellular processes at the bio‐membrane level. [ABSTRACT FROM AUTHOR]

Maternal exercise (ME) has been established as a useful non‐pharmacological intervention to improve infant metabolic health; however, mechanistic insight behind these adaptations remains mostly confined to animal models. Infant mesenchymal stem cells (MSCs) give rise to infant tissues (e.g., skeletal muscle), and remain involved in mature tissue maintenance. Importantly, these cells maintain metabolic characteristics of an offspring donor and provide a model for the investigation of mechanisms behind infant metabolic health improvements. We used undifferentiated MSC to investigate if ME affects infant MSC mitochondrial function and insulin action, and if these adaptations are associated with lower infant adiposity. We found that infants from exercising mothers have improvements in MSC insulin signaling related to higher MSC respiration and fat oxidation, and expression and activation of energy‐sensing and redox‐sensitive proteins. Further, we found that infants exposed to exercise in utero were leaner at 1 month of age, with a significant inverse correlation between infant MSC respiration and infant adiposity at 6 months of age. These data suggest that infants from exercising mothers are relatively leaner, and this is associated with higher infant MSC mitochondrial respiration, fat use, and insulin action. [ABSTRACT FROM AUTHOR]

Recent developments in single‐cell sequencing technology enable the acquisition of entire transcriptome data. Understanding the underlying mechanism and identifying the driving force of transcriptional regulation governing cell function directly from these data remains challenging. This study reconstructs a continuous vector field of the cell cycle based on discrete single‐cell RNA velocity to quantify the single‐cell global nonequilibrium dynamic landscape‐flux. It reveals that large fluctuations disrupt the global landscape and genetic perturbations alter landscape‐flux, thus identifying key genes in maintaining cell cycle dynamics and predicting associated functional effects. Additionally, it quantifies the fundamental energy cost of the cell cycle initiation and unveils that sustaining the cell cycle requires curl flux and dissipation to maintain the oscillatory phase coherence. This study enables the inference of the cell cycle gene regulatory networks directly from the single‐cell transcriptomic data, including the feedback mechanisms and interaction intensity. This provides a golden opportunity to experimentally verify the landscape‐flux theory and also obtain its associated quantifications. It also offers a unique framework for combining the landscape‐flux theory and single‐cell high‐through sequencing experiments for understanding the underlying mechanisms of the cell cycle and can be extended to other nonequilibrium biological processes, such as differentiation development and disease pathogenesis. [ABSTRACT FROM AUTHOR]

Fracture healing is a complex staged repair process in which the mechanical environment plays a key role. Bone tissue is very sensitive to mechanical stress stimuli, and the literature suggests that appropriate stress can promote fracture healing by altering cellular function. However, fracture healing is a coupled process involving multiple cell types that balance and limit each other to ensure proper fracture healing. The main cells that function during different stages of fracture healing are different, and the types and molecular mechanisms of stress required are also different. Most previous studies have used a single mechanical stimulus on individual mechanosensitive cells, and there is no relatively uniform standard for the size and frequency of the mechanical stress. Analyzing the mechanisms underlying the effects of mechanical stimulation on the metabolic regulation of signaling pathways in cells such as in bone marrow mesenchymal stem cells (BMSCs), osteoblasts, chondrocytes, and osteoclasts is currently a challenging research hotspot. Grasping how stress affects the function of different cells at the molecular biology level can contribute to the refined management of fracture healing. Therefore, in this review, we summarize the relevant literature and describe the effects of mechanical stress on cells associated with fracture healing, and their possible signaling pathways, for the treatment of fractures and the further development of regenerative medicine. [ABSTRACT FROM AUTHOR]

Aims: Peripheral immune cells infiltrating into the brain trigger neuroinflammation after an ischemic stroke. Partial immune cells reprogram their function for neural repair. Which immune cells promote ischemic brain recovery needs further identification. Methods: We performed single‐cell transcriptomic profiling of CD45high immune cells isolated from the ischemic hemisphere at subacute (5 days) and chronic (14 days) stages after ischemic stroke. Results: A subset of phagocytic macrophages was associated with neuron projection regeneration and tissue remodeling. We also identified a unique type of T cells with highly expressed macrophage markers, including C1q, Apoe, Hexb, and Fcer1g, which showed high abilities in tissue remodeling, myelination regulation, wound healing, and anti‐neuroinflammation. Moreover, natural killer cells decreased cytotoxicity and increased energy and metabolic function in the chronic stage after ischemic stroke. Two subgroups of neutrophils upregulated CCL signals to recruit peripheral immune cells and released CXCL2 to keep self‐recruiting at the chronic stage. Conclusions: We identified subsets of peripheral immune cells that may provide potential therapeutic targets for promoting poststroke recovery. [ABSTRACT FROM AUTHOR]

Despite the great body of research done on Alzheimer's disease, the underlying mechanisms have not been vividly investigated. To date, the accumulation of amyloid‐beta plaques and tau tangles constitutes the hallmark of the disease; however, dysregulation of the mammalian target of rapamycin (mTOR) seems to be significantly involved in the pathogenesis of the disease as well. mTOR, as a serine–threonine protein kinase, was previously known for controlling many cellular functions such as cell size, autophagy, and metabolism. In this regard, mammalian target of rapamycin complex 1 (mTORC1) may leave anti‐aging impacts by robustly inhibiting autophagy, a mechanism that inhibits the accumulation of damaged protein aggregate and dysfunctional organelles. Formation and aggregation of neurofibrillary tangles and amyloid‐beta plaques seem to be significantly regulated by mTOR signaling. Understanding the underlying mechanisms and connection between mTOR signaling and AD may suggest conducting clinical trials assessing the efficacy of rapamycin, as an mTOR inhibitor drug, in managing AD or may help develop other medications. In this literature review, we aim to elaborate mTOR signaling network mainly in the brain, point to gaps of knowledge, and define how and in which ways mTOR signaling can be connected with AD pathogenesis and symptoms. [ABSTRACT FROM AUTHOR]

Microglia, the major resident immune cells in the central nervous system, serve as the frontline soldiers against cerebral ischemic injuries, possibly along with metabolic alterations. However, signaling pathways involved in the regulation of microglial immunometabolism in ischemic stroke remain to be further elucidated. In this study, using single‐nuclei RNA sequencing, a microglial subcluster up‐regulated in ischemic brain tissues is identified, with high expression of Igf1 and Trem2, neuroprotective transcriptional signature and enhanced oxidative phosphorylation. Microglial depletion by PLX3397 exacerbates ischemic brain damage, which is reversed by repopulating the microglia with high Igf1 and Trem2 phenotype. Mechanistically, Igf1 serves as one of the major down‐stream molecules of Trem2, and Trem2‐Igf1 signaling axis regulates microglial functional and metabolic profiles, exerting neuroprotective effects on ischemic stroke. Overexpression of Igf1 and supplementation of cyclocreatine restore microglial glucometabolic levels and cellular functions even in the absence of Trem2. These findings suggest that Trem2‐Igf1 signaling axis reprograms microglial immunometabolic profiles and shifts microglia toward a neuroprotective phenotype, which has promising therapeutic potential in treating ischemic stroke. [ABSTRACT FROM AUTHOR]

Fatty acid binding proteins (Fabps) are small soluble proteins that are abundant in the cytosol. These proteins are known to bind a myriad of small hydrophobic molecules and have been postulated to serve a variety of roles, yet their precise functions have remained an enigma over half a century of study. Here, we consider recent findings, along with the cumulative findings contributed by many laboratories working on Fabps over the last half century, to synthesize a new outlook for what functions Fabps serve in cells and organisms. Collectively, the findings illustrate that Fabps function as versatile multi‐purpose devices serving as sensors, conveyors and modulators to enable cells to detect and handle a specific class of metabolites, and to adjust their metabolic capacity and efficiency. [ABSTRACT FROM AUTHOR]

Calorie restriction (CR) has been repeatedly shown to prevent cancer, diabetes, hypertension, and other age-related diseases in a wide range of animals, including non-human primates and humans. In rodents, CR also increases lifespan and is a powerful tool for studying the aging process. Recently, it has been reported in mice that dietary fat plays an important role in determining lifespan extension with 40% CR. In these conditions, animals fed lard as dietary fat showed an increased longevity compared with mice fed soybean or fish oils. In this paper, we study the effect of these dietary fats on structural and physiological parameters of kidney from mice maintained on 40% CR for 6 and 18 months. Analyses were performed using quantitative electron microcopy techniques and protein expression in Western blots. CR mitigated most of the analyzed age-related parameters in kidney, such as glomerular basement membrane thickness, mitochondrial mass in convoluted proximal tubules and autophagic markers in renal homogenates. The lard group showed improved preservation of several renal structures with aging when compared to the other CR diet groups. These results indicate that dietary fat modulates renal structure and function in CR mice and plays an essential role in the determination of health span in rodents. [ABSTRACT FROM AUTHOR]

Spontaneous subarachnoid hemorrhage (SAH) is one of the most devastating forms of stroke, with limited treatment modalities and poor patient outcomes. Previous studies have proposed multiple prognostic factors; however, relative research on treatment has not yet yielded favorable clinical outcomes. Moreover, recent studies have suggested that early brain injury (EBI) occurring within 72 h after SAH may contribute to its poor clinical outcomes. Oxidative stress is recognized as one of the main mechanisms of EBI, which causes damage to various subcellular organelles, including the mitochondria, nucleus, endoplasmic reticulum (ER), and lysosomes. This could lead to significant impairment of numerous cellular functions, such as energy supply, protein synthesis, and autophagy, which may directly contribute to the development of EBI and poor long‐term prognostic outcomes. In this review, the mechanisms underlying the connection between oxidative stress and subcellular organelles after SAH are discussed, and promising therapeutic options based on these mechanisms are summarized. [ABSTRACT FROM AUTHOR]

Mitochondria play essential roles in metabolic support and signaling within all cells. Congenital and acquired defects in mitochondria are responsible for several pathologies, including premature entrance to cellar senescence. Conversely, we examined the consequences of dysfunctional telomere‐driven cellular senescence on mitochondrial biogenesis and function. We drove senescence in vitro and in vivo by deleting the telomere‐binding protein TRF2 in fibroblasts and hepatocytes, respectively. Deletion of TRF2 led to a robust DNA damage response, global changes in transcription, and induction of cellular senescence. In vitro, senescent cells had significant increases in mitochondrial respiratory capacity driven by increased cellular and mitochondrial volume. Hepatocytes with dysfunctional telomeres maintained their mitochondrial respiratory capacity in vivo, whether measured in intact cells or purified mitochondria. Induction of senescence led to the upregulation of overlapping and distinct genes in fibroblasts and hepatocytes, but transcripts related to mitochondria were preserved. Our results support that mitochondrial function and activity are preserved in telomere dysfunction‐induced senescence, which may facilitate continued cellular functions. [ABSTRACT FROM AUTHOR]

The free spindled cells of the lamina propria of the gut have been reported as showing fibroblastic, smooth-muscle and myofibroblastic differentiation. A precise understanding of the differentiation of these cells is essential for appreciating their functions, and this paper addresses this question using ultrastructural analysis. Histologically normal samples from different areas of the gastrointestinal tract were studied. Both subepithelial stromal cells, lying immediately beneath the basal lamina, and the deeper interstitial stromal cells, were studied. Subepithelial and interstitial cells had comparable features, reinforcing the idea that these formed a single reticulum of cells. Two major cell types were identified. Some were smooth-muscle cells, on the basis of abundant myofilaments with focal densities, glycogen, an irregular cell surface, focal lamina and multiple attachment plaques alternating with plasmalemmal caveolae. Some cells had a lesser expression of these markers, especially of myofilaments, and were regarded as poorly differentiated smooth-muscle cells and descriptively referred to as 'myoid'. Other cells were fibroblastic to judge by prominent rough endoplasmic reticulum, an absence of myofilaments and lamina, but presence of focal adhesions. The fibronexus junctions of true myofibroblasts were not seen. The study emphasises that the smooth-muscle actin immunoreactivity in this anatomical site resides in smooth-muscle cells and not in myofibroblasts, a view consistent with earlier ultrastructural and immunostaining results. The recognition that these cells are showing smooth-muscle or fibroblastic but not true myofibroblastic differentiation should inform our understanding of the function of these cells. [ABSTRACT FROM AUTHOR]

Abstract. The haematopoietic stem cell (HSC) population supports a tremendous cellular production over the course of an animal's lifetime, e.g. adult humans produce their body weight in red cells, white cells and platelets every 7 years, while the mouse produces about 60% of its body weight in the course of a 2 year lifespan. Understanding how the HSC population carries this out is of interest and importance, and a first step in that understanding involves the characterization of HSC kinetics. Using previously published continuous labelling data (of Bradford et al. 1997 and Cheshier et al. 1999 ) from mouse HSC and a standard G 0 model for the cell cycle, the steady state parameters characterizing these HSC populations are derived. It is calculated that in the mouse the differentiation rate ranges between about 0.01 and 0.02, the rate of cell re-entry from G 0 back into the proliferative phase is between 0.02 and 0.05, the rate of apoptosis from the proliferative phase is between 0.07 and 0.23 (all units are days -1 ), and the duration of the proliferative phase is between 1.4 and 4.3 days. These values are compared with previously obtained values derived from the modelling by Abkowitz and colleagues of long-term haematopoietic reconstitution in the cat ( Abkowitz et al. 1996 ) and the mouse ( Abkowitz et al. 2000 ). It is further calculated using the estimates derived in this paper and other data on mice that between the HSC and the circulating blood cells there are between 17 and 19.5 effective cell divisions giving a net amplification of between ~170 000 and ~720 000. [ABSTRACT FROM AUTHOR]

Despite significant advancements in in vitro cardiac modeling approaches, researchers still lack the capacity to obtain in vitro measurements of a key indicator of cardiac function: contractility, or stroke volume under specific loading conditions—defined as the pressures to which the heart is subjected prior to and during contraction. This work puts forward a platform that creates this capability, by providing a means of dynamically controlling loading conditions in vitro. This dynamic tissue loading platform consists of a thin magnetoresponsive hydrogel cantilever on which 2D engineered myocardial tissue is cultured. Exposing the cantilever to an external magnetic field—generated by positioning magnets at a controlled distance from the cantilever—causes the hydrogel film to stretch, creating tissue load. Next, cell contraction is induced through electrical stimulation, and the force of the contraction is recorded, by measuring the cantilever's deflection. Force–length‐based measurements of contractility are then derived, comparable to clinical measurements. In an illustrative application, the platform is used to measure contractility both in untreated myocardial tissue and in tissue exposed to an inotropic agent. Clear differences are observed between conditions, suggesting that the proposed platform has significant potential to provide clinically relevant measurements of contractility. [ABSTRACT FROM AUTHOR]

Combinational immunotherapy of dendritic cell (DC) vaccines and anti‐programmed cell death protein 1 antibodies (aPD1) has been regarded as a promising strategy for cancer treatment because it not only induces tumor‐specific T cell immune responses, but also prevents failure of T cell functions by the immune suppressive milieu of tumors. Microneedles have emerged as an innovative platform for efficient transdermal immunotherapies. However, co‐delivery of DC vaccines and aPD1 via microneedles has not been studied since conventional microneedle platforms are unsuitable for fragile therapeutics like living cells and antibodies. This study employs our newly invented cryomicroneedles (cryoMNs) to co‐deliver DC vaccines and aPD1 for the combinational immunotherapy. CryoMNs are fabricated by stepwise cryogenic micromoulding of cryogenic medium with pre‐suspended DCs and aPD1, which are further integrated with a homemade handle for convenient application. The viability of DCs in cryoMNs remains above 85%. CryoMNs are mechanically strong enough to insert into porcine and mouse skin, successfully releasing DCs and aPD1 inside skin tissue after melting. Co‐delivery of ovalbumin (OVA)‐pulsed DCs (OVA‐DCs) and aPD1 via cryoMNs induced higher antigen‐specific cellular immune responses compared with the mono‐delivery of OVA‐DCs or aPD1. Finally, administration with cryoMNs co‐encapsulated with OVA‐DCs and aPD1 increases the infiltration of effector T cells in the tumor, resulting in stronger anti‐tumor therapeutic efficacy in both prophylactic and therapeutic melanoma models compared with administration with cryoMNs loaded with OVA‐DCs or aPD1. This study demonstrates the great potential of cryoMNs as a co‐delivery system of therapeutic cells and biomacromolecules for combinational therapies. [ABSTRACT FROM AUTHOR]

Sleep is essential for maintaining health. Indeed, sleep loss is closely associated with multiple health problems, including gastrointestinal disorders. However, it is not yet clear whether sleep loss affects the function of intestinal stem cells (ISCs). Mechanical sleep deprivation and sss mutant flies were used to generate the sleep loss model. qRT‐PCR was used to measure the relative mRNA expression. Gene knock‐in flies were used to observe protein localization and expression patterns. Immunofluorescence staining was used to determine the intestinal phenotype. The shift in gut microbiota was observed using 16S rRNA sequencing and analysis. Sleep loss caused by mechanical sleep deprivation and sss mutants disturbs ISC proliferation and intestinal epithelial repair through the brain–gut axis. In addition, disruption of SSS causes gut microbiota dysbiosis in Drosophila. As regards the mechanism, gut microbiota and the GABA signalling pathway both partially played a role in the sss regulation of ISC proliferation and gut function. The research shows that sleep loss disturbed ISC proliferation, gut microbiota, and gut function. Therefore, our results offer a stem cell perspective on brain–gut communication, with details on the effect of the environment on ISCs. [ABSTRACT FROM AUTHOR]

Objective: Gain of function variants in the sodium‐activated potassium channel KCNT1 have been associated with pediatric epilepsy disorders. Here, we systematically examine a spectrum of KCNT1 variants and establish their impact on channel function in multiple cellular systems. Methods: KCNT1 variants identified from published reports and genetic screening of pediatric epilepsy patients were expressed in Xenopus oocytes and HEK cell lines. Variant impact on current magnitude, current–voltage relationships, and sodium ion modulation were examined. Results: We determined basic properties of KCNT1 in Xenopus oocyte and HEK systems, including the role of extra‐ and intracellular sodium in regulating KCNT1 activity. The most common six KCNT1 variants demonstrated strong gain of function (GOF) effects on one or more channel properties. Analysis of 36 total variants identified phenotypic heterogeneity but a strong tendency for pathogenic variants to exert GOF effects on channel properties. By controlling intracellular sodium, we demonstrate that multiple pathogenic KCNT1 variants modulate channel voltage dependence by altering the sensitivity to sodium ions. Significance: This study represents the largest systematic functional examination of KCNT1 variants to date. We both confirm previously reported GOF channel phenotypes and expand the number of variants with in vitro GOF effects. Our data provide further evidence that novel KCNT1 variants identified in epilepsy patients lead to disease through generalizable GOF mechanisms including increases in current magnitude and/or current–voltage relationships. [ABSTRACT FROM AUTHOR]

Epidermal growth factor (EGF) is a growth factor that plays a pivotal role in wound healing and maintaining tissue homeostasis by regulating cell survival, proliferation, migration, and differentiation. Exogenous administration of bioidentical human recombinant epidermal growth factor (rhEGF) has been known to promote skin wound healing, although rhEGF is increasingly being used in drug delivery systems and nanotechnology. However, despite considerable attention being focused on the potential clinical applications of rhEGF in several dermatological conditions beyond wound healing, the number of studies still remains relatively low. Herein, we conducted a literature search of PubMed/Medline and Google Scholar databases to retrieve published literature related to rhEGF and summarised the effects of rhEGF in the treatment of various wound types, radiotherapy or chemotherapy‐related skin reactions, atopic dermatitis, skin aging, and post‐inflammatory hyperpigmentation. [ABSTRACT FROM AUTHOR]

Vaccines based on tumour‐specific antigens are a promising approach for immunotherapy. However, the clinical efficacy of tumour‐specific antigens is still challenging. Twelve conjugates with self‐assembly properties were designed and synthesized using MAGE‐A1 peptide and TLR2 agonist, combined with different covalent bonds. All the developed conjugates formed spherical nanoparticles with a diameter of approximately 150 nm, and enhanced the efficacy of the peptide vaccines with the better targeting of lymph nodes. All the conjugates could well bind to serum albumin and improve the plasma stability of the individual antigenic peptides. In particular, conjugate 6 (N‐Ac PamCS‐M‐6) had a more significant ability to promote dendritic cell maturation, CD8+ T cell activation, and subsequent killing of tumour cells, with an in vivo tumour inhibition rate of 70 ± 2.9%. The interaction between specific response and the different conjugation modes was further explored, thereby providing a fundamental basis for novel immune anti‐tumour molecular platforms. [ABSTRACT FROM AUTHOR]

Topologically associating domains (TADs) are functional chromatin units with hierarchical structure. However, the existence, prevalence, and dynamics of such hierarchy in single cells remain unexplored. Here, a new generation TAD‐like domain (TLD) detection algorithm, named deDoc2, to decode the hierarchy of TLDs in single cells, is reported. With dynamic programming, deDoc2 seeks genome partitions with global minimal structure entropy for both whole and local contact matrix. Notably, deDoc2 outperforms state‐of‐the‐art tools and is one of only two tools able to identify the hierarchy of TLDs in single cells. By applying deDoc2, it is showed that the hierarchy of TLDs in single cells is highly dynamic during cell cycle, as well as among human brain cortex cells, and that it is associated with cellular identity and functions. Thus, the results demonstrate the abundance of information potentially encoded by TLD hierarchy for functional regulation. The deDoc2 can be freely accessed at https://github.com/zengguangjie/deDoc2. [ABSTRACT FROM AUTHOR]

Self‐assembling protein filaments are at the heart of cell function. Among them, tubulin‐like proteins are essential for cell division, DNA segregation and cytoskeletal functions across the domains of life. FtsZ and tubulin share their core structures, a characteristic nucleotide‐binding pocket and similar protofilament architecture. GTP hydrolysis between consecutive subunits drives their assembly dynamics. Two recent studies provide previously missing, filament atomic structures of bacterial FtsZ and a recently discovered archaeal tubulin in their nucleotide triphosphate‐bound states. Both filament structures reveal strikingly conserved interfacial GTPase active sites, with Mg2+ and K+/Na+ cations and an NxDxxD/E triad of catalytic residues, probably inherited from the common ancestor of FtsZs and tubulins. Moreover, both proteins exhibit nucleotide‐regulated subunit association mediated by interfacial water bridges, as well as polymerization‐induced structural changes, likely enabling related dynamic assembly mechanisms. [ABSTRACT FROM AUTHOR]

Background and Purpose: Piezo1 channels are mechanosensitive cationic channels that are activated by mechanical stretch or shear stress. Endothelial Piezo1 activation by shear stress caused by blood flow induces ATP release from endothelial cells; however, the link between shear stress and endothelial ATP production is unclear. Experimental Approach: The mitochondrial respiratory function of cells was measured by using high‐resolution respirometry system Oxygraph‐2k. The intracellular Ca2+ concentration was evaluated by using Fluo‐4/AM and mitochondrial Ca2+ concentration by Rhod‐2/AM. Key Results: The specific Piezo1 channel activator Yoda1 or its analogue Dooku1 increased [Ca2+]i in human umbilical vein endothelial cells (HUVECs), and both Yoda1 and Dooku1 increased mitochondrial oxygen consumption rates (OCRs) and mitochondrial ATP production in HUVECs and primary cultured rat aortic endothelial cells (RAECs). Knockdown of Piezo1 inhibited Yoda1‐ and Dooku1‐induced increases of mitochondrial OCRs and mitochondrial ATP production in HUVECs. The shear stress mimetics, Yoda1 and Dooku1, and the Piezo1 knock‐down technique also demonstrated that Piezo1 activation increased glycolysis in HUVECs. Chelating extracellular Ca2+ with EGTA or chelating cytosolic Ca2+ with BAPTA‐AM did not affect Yoda1‐ and Dooku1‐induced increases of mitochondrial OCRs and ATP production, but chelating cytosolic Ca2+ inhibited Yoda1‐ and Dooku1‐induced increase of glycolysis. Confocal microscopy showed that Piezo1 channels are present in mitochondria of endothelial cells, and Yoda1 and Dooku1 increased mitochondrial Ca2+ in endothelial cells. Conclusion and Implications: Piezo1 channel activation stimulates ATP production through enhancing mitochondrial respiration and glycolysis in vascular endothelial cells, suggesting a novel role of Piezo1 channel in endothelial ATP production. [ABSTRACT FROM AUTHOR]

Stem cells represent an ideal source for regenerative medicine; however, longitudinal assessment of stem cell phenotype and function is challenging. Contrastingly, a convolutional neural network (CNN) algorithm can automatically extract the image features and produce highly accurate image recognition. Thus, this study implements CNN to establish stable and reproducible cell culture experiments by predicting a unique morphology of pluripotent stem cell (PSC) lines. Interestingly, the algorithm distinguishes the PSC lines cultured in the different cell culture conditions, such as the presence or absence of small molecules and/or the long‐ or short‐term culture in our induced PSC (iPSC) models, which include iPSC lines with abnormal gene expression patterns and genomic abnormalities. Our deep learning technology accurately classifies the various cell lines with or without genetic defects using only the cell images, without any labeling process. This suggests that the CNN system may simplify the various tasks involving stable cell cultures and their differentiation. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to provide a concise overview of the role of immune cells in rejection and infection after lung transplantation. Methods: Based on previous clinical and basic studies, the role of various types of immune cells in the development of rejection and infection after lung transplantation is summarized. Results: Immune cell functional status is strongly associated with common complications after lung transplantation, such as primary graft dysfunction, infection and occlusive bronchitis syndrome. Targeted balancing of immune cell tolerance and rejection is an important tool for successful lung transplantation. Conclusion: A comprehensive understanding of immune cell function and the mechanisms that balance immune tolerance and immune rejection may be a crucial factor in improving survival after lung transplantation. [ABSTRACT FROM AUTHOR]

Migrasomes are enigmatic organelles with a pomegranate‐like shape that form along the retraction fibres in migrating cells. They have been linked to several cellular functions including intercellular communication, by local transfer and at distance, and the disposal of damaged cellular materials, such as mitochondria. Yongbin Ma et al have uncovered that a unique type of lipid‐bilayer membrane vesicles is released from migrasomes, and called under the name migrasome‐derived nanoparticles (MDNP). Their observations suggest that MDNP can be generated upon both rupture and budding of migrasomes, ultimately unloading their content in the microenvironment. [ABSTRACT FROM AUTHOR]

The mammary gland is a vital exocrine organ that has evolved in mammals to secrete milk and provide nutrition to ensure the growth and survival of the neonate The mouse mammary gland displays extraordinary plasticity each time the female undergoes pregnancy and lactation, including a sophisticated process of tertiary branching and alveologenesis to form a branched epithelial tree and subsequently milk‐producing alveoli. Upon the cessation of lactation, the gland remodels back to a simple ductal architecture via highly regulated involution processes. At the cellular level, the plasticity is characterised by proliferation of mammary cell populations, differentiation and apoptosis, accompanied by major changes in cell function and morphology. The mammary epithelium requires a specific stromal environment to grow, known as the mammary fat pad. Mammary adipocytes are one of the most prominent cell types in the fat pad, but despite their vast proportion in the tissue and their crucial interaction with epithelial cells, their physiology remains largely unknown. Over the past decade, the need to understand the properties and contribution of mammary adipocytes has become more recognised. However, the development of adequate methods and protocols to study this cellular niche is still lagging, partially due to their fragile nature, the difficulty of isolating them, the lack of reliable cell surface markers and the heterogenous environment in this tissue, which differs from other adipocyte depots. Here, we describe a new rapid and simple flow cytometry protocol specifically designed for the analysis and isolation of mouse mammary adipocytes across mammary gland developmental stages. [ABSTRACT FROM AUTHOR]

The effect of triplex-forming oligonucleotides (TFO) on the transcription activity of T7 RNA polymerase has been investigated by an in vitro assay. The TFOs, either containing only phosphate (PO[sub2]) or phosphate and phosphorothioate (POS) internucleotide linkages, were targeted to a 30-bp homopurine. homopyrimidine (R.Y) site cloned in plasmid Bluescript KS+ about four helical turns downstream from the T7 RNA promoter. Band-shift and ultraviolet absorption melting experiments showed that the designed pyrimidine PO[sub2] and POS TFOs form stable triple-helical complexes with the R.Y target duplex (the delta GTFO values of triplex formation vary from -42 to -63 kJ/mol). The triple-helical complexes resulting from POS oligonucleotides were less stable (by 4-12 kJ/mol) than those obtained with PO[sub2] analogues, the magnitude of destabilization being dependent on the number of POS groups present in the third strand. The designed TFOs were shown to efficiently repress bacteriophage T7 RNA polymerase transcription under different experimental conditions. The repression depended on pH, TFO concentration and temperature. When the TFO/template ratio was fixed to 100, a strong repressive effect was observed with normal and phosphorothioate pyrimidine TFOs, also under physiological conditions. In contrast, a purine-rich oligonucleotide containing 44% of guanine residues promoted only a weak transcription inhibition, even at a TFO/template ratio as high as 750. Both PO[sub2]- and POS-containing pyrimidine TFOs produced their strong repressive effect on T7 RNA polymerase transcription even when they were added to the reaction mixture simultaneously with the polymerase. A mechanism of transcription repression is discussed. The data reported in this paper are useful for designing oligonucleotides acting as artificial repressors in the antigene strategy and indicate that the R.Y target need not to be precisely confined to the promoter. [ABSTRACT FROM AUTHOR]

Eukaryotic cells control their intracellular pH using ion-transporting systems that are situated in the plasma membrane. This paper describes the different mechanisms that are involved and how their activity is regulated. [ABSTRACT FROM AUTHOR]

Mononuclear cell migration across the endothelium and through connective tissue into inflammatory sites is a multi-step process. After adhesion to the endothelium, there is an initial change in shape from spherical to irregular, followed by the migratory phase itself in which the cells constantly change in shape. In this paper we have investigated the possibility that the shape-changing in this latter phase is controlled by serine/threonine phosphorylation. For this purpose, we used a spontaneously shape- changing variant of U937 monocytoid cells as well as human peripheral blood lymphocytes that had been previously activated by anti-CD3. To test the role o f phosphorylation in shape-changing, a wide range of serine/threonine kinase inhibitors was tested, including ML-7, KT5720, KT5823, H7, H8, staurosporine, calphostin C, sphingosine, bisindolylmaleimide, chelerythrine and KN-62. Only those compounds which inhibited protein kinase C prevented lymphocyte and U937 shape-change and transmigration across polycarbonate filters. However, one specific protein kinase C inhibitor, bisindolylmaleimide, stimulated lymphocyte shape-change, [n conclusion, these studies show that activation of a serine/threonine kinase is necessary for the constant shape-changing required for motility of mononuclear cells. The kinase may be a protein kinase C isotype or a closely related enzyme. [ABSTRACT FROM AUTHOR]

Background: Radiotherapy is an important clinical treatment for patients with lung squamous cell carcinoma (LUSC), and resistance to radiotherapy is an important cause of recurrence and metastasis in LUSC. The aim of this study was to establish and explore the biological characteristics of radioresistant LUSC cells. Materials and methods: The LUSC cell lines NCI‐H2170 and NCI‐H520 were irradiated (4 Gy × 15Fraction). Radiosensitivity, cell apoptosis, cell cycle, and DNA damage repair were measured by clonogenic survival assay, flow cytometry, immunofluorescence for γ‐H2AX foci, and Comet assay, respectively. Activation of p‐ATM(Ser1981), p‐CHK2(Th68), p‐DNA‐PKcs (Ser2056), and Ku70/Ku80 was measured by western blot. Proteomics was used to explore the differential genes and enriched signaling pathways between radioresistant cell lines and parental lines. In vivo nude mouse xenograft experiments further verified the feasibility of the radioresistant LUSC cell lines. Results: After fractionated irradiation (total dose of 60 Gy), radioresistant cells had decreased radiosensitivity, increased G0/G1 phase arrest, enhanced DNA damage repair ability, and through the ATM/CHK2 and DNA‐PKcs/Ku70 pathways regulated double strands break. The upregulated differential genes in radioresistant cell lines were mainly enriched in biological pathways such as cell migration and extracellular matrix (ECM)‐receptor interaction. In vivo verification of decreased radiosensitivity of radioresistant cells Conclusions: Radioresistant LUSC cell lines were established by fractional radiotherapy, which regulates IR‐induced DNA damage repair through ATM/CHK2 and DNA‐PKcs/Ku70. Tandem Mass Tags (TMT) quantitative proteomics found that the biological process pathway of cell migration and ECM‐receptor interaction are upregulated in LUSC radioresistant cells. [ABSTRACT FROM AUTHOR]

Intramuscular lipid droplets (LDs) and mitochondria are essential organelles in cellular communication and metabolism, supporting local energy demands during muscle contractions. While insulin resistance impacts cellular functions and systems within the skeletal muscle, it remains unclear whether the interaction of LDs and mitochondria is affected by exercise and the role of obesity and type 2 diabetes. By employing transmission electron microscopy (TEM), we aimed to investigate the effects of 1 h of ergometry cycling on LD morphology, subcellular distribution and mitochondrial contact in skeletal muscle fibres of patients with type 2 diabetes and glucose‐tolerant lean and obese controls, matched for equal exercise intensities. Exercise did not change LD volumetric density, numerical density, profile size or subcellular distribution. However, evaluated as the magnitude of inter‐organelle contact, exercise increased the contact between LDs and mitochondria with no differences between the three groups. This effect was most profound in the subsarcolemmal space of type 1 muscle fibres, and here the absolute contact length increased on average from ∼275 to ∼420 nm. Furthermore, the absolute contact length before exercise (ranging from ∼140 to ∼430 nm) was positively associated with the fat oxidation rate during exercise. In conclusion, we showed that acute exercise did not mediate changes in the LD volume fractions, numbers or size but increased the contact between LDs and mitochondria, irrespective of obesity or type 2 diabetes. These data suggest that the increased LD–mitochondria contact with exercise is not disturbed in obesity or type 2 diabetes. Key points: Type 2 diabetes is associated with altered interactivity between lipid droplets (LDs) and mitochondria in the skeletal muscle.Physical contact between the surface of LDs and the surrounding mitochondrial network is considered favourable for fat oxidation.We show that 1 h of acute exercise increases the length of contact between LDs and mitochondria, irrespective of obesity or type 2 diabetes.This contact length between LDs and mitochondria is not associated with a net decrease in the LD volumetric density after the acute exercise. However, it correlates with the fat oxidation rate during exercise.Our data establish that exercise mediates contact between LDs and the mitochondrial network and that this effect is not impaired in individuals with type 2 diabetes or obesity. [ABSTRACT FROM AUTHOR]

The roots of legume plant play a crucial role in nitrogen fixation. However, the transcriptomes of different cell types of legume root and their functions remain largely unknown. Here, we performed single‐cell RNA sequencing and profiled more than 22,000 single cells from root tips of Lotus japonicus, a model species of legume. We identified seven clusters corresponding to seven major cell types, which were validated by in situ hybridization. Further analysis revealed regulatory programs including phytohormone and nodulation associated with specific cell types, and revealed conserved and diverged features for the cell types. Our results represent the first single‐cell resolution transcriptome for legume root tips and a valuable resource for studying the developmental and physiological functions of various cell types in legumes. [ABSTRACT FROM AUTHOR]

The Transient Receptor Potential Vanilloid 4 (TRPV4) channel has been shown to function in many physiological and pathophysiological processes. Despite abundant information on its importance in physiology, very few endogenous agonists for this channel have been described, and very few underlying mechanisms for its activation have been clarified. TRPV4 is expressed by several types of cells, such as vascular endothelial, and skin and lung epithelial cells, where it plays pivotal roles in their function. In the present study, we show that TRPV4 is activated by lysophosphatidic acid (LPA) in both endogenous and heterologous expression systems, pinpointing this molecule as one of the few known endogenous agonists for TRPV4. Importantly, LPA is a bioactive glycerophospholipid, relevant in several physiological conditions, including inflammation and vascular function, where TRPV4 has also been found to be essential. Here we also provide mechanistic details of the activation of TRPV4 by LPA and another glycerophospholipid, lysophosphatidylcholine (LPC), and show that LPA directly interacts with both the N‐ and C‐terminal regions of TRPV4 to activate this channel. Moreover, we show that LPC activates TRPV4 by producing an open state with a different single‐channel conductance to that observed with LPA. Our data suggest that the activation of TRPV4 can be finely tuned in response to different endogenous lipids, highlighting this phenomenon as a regulator of cell and organismal physiology. Key points: The Transient Receptor Potential Vaniloid (TRPV) 4 ion channel is a widely distributed protein with important roles in normal and disease physiology for which few endogenous ligands are known.TRPV4 is activated by a bioactive lipid, lysophosphatidic acid (LPA) 18:1, in a dose‐dependent manner, in both a primary and a heterologous expression system.Activation of TRPV4 by LPA18:1 requires residues in the N‐ and C‐termini of the ion channel.Single‐channel recordings show that TRPV4 is activated with a decreased current amplitude (conductance) in the presence of lysophosphatidylcholine (LPC) 18:1, while LPA18:1 and GSK101 activate the channel with a larger single‐channel amplitude.Distinct single‐channel amplitudes produced by LPA18:1 and LPC18:1 could differentially modulate the responses of the cells expressing TRPV4 under different physiological conditions. [ABSTRACT FROM AUTHOR]

The nucleosome is the fundamental subunit of chromatin. Nucleosome structures are formed by the combination of histone octamers and genomic DNA. Through a systematic and precise process of folding and compression, these structures form a 30‐nm chromatin fibre that is further organized within the nucleus in a hierarchical manner, known as the 3D genome. Understanding the intricacies of chromatin structure and the regulatory mode governing chromatin interactions is essential for unravelling the complexities of cellular architecture and function, particularly in relation to cell fate determination, regeneration, and the development of diseases. Here, we provide a general overview of the hierarchical structure of chromatin as well as of the evolution of chromatin conformation capture techniques. We also discuss the dynamic regulatory changes in higher‐order chromatin structure that occur during stem cell lineage differentiation and somatic cell reprogramming, potential regulatory insights at the chromatin level in organ regeneration, and aberrant chromatin regulation in diseases. [ABSTRACT FROM AUTHOR]

Oncogene SET Domain Bifurcated 1 (SETDB1)/ESET, an H3K9 methyltransferase, was originally discovered over two decades ago; however, its function in the immune response was not first reported until 2011. SETDB1 immune functions include B cell maturation, T cell activity regulation, and immune escape in cancer cells. In B lymphocytes, SETDB1 mediates the transition from pro‐B to pre‐B cells and represses endogenous retroviruses (ERV) to encourage B cell lineage differentiation and maturation. SETDB1 alters T cell function by methylating IL‐2 and IL‐17 promoters and mediating T cell lineage commitment and development. In addition, SETDB1 plays a critical role in ERV silencing within a variety of immune cells, which can indirectly weaken the immune response. Although SETDB1 is critical for normal immune cell function, overexpression in cancer cells negatively impacts immune cell fights against cancer through decreased tumour immunogenicity. Within cancer cells, SETDB1 overexpression represses production and infiltration of antitumour immune cells, mediates immune escape through TE and ERV silencing, represses the type I interferon pathway, and interferes in immune checkpoint blockade (ICB) outcomes by regulation of PD‐L1 expression and IFN signalling. In this review, we further discuss the immunological mechanisms of SETDB1 in normal and cancerous cells and its implications in cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Background: Circular RNAs (circRNAs) have been reported to play roles in lung cancer development. The purpose of this work was to explore the function and mechanism of circ_0043256 in lung cancer tumorigenesis. Methods: Quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot were used for the detection of the levels of genes and proteins. Cell growth, angiogenesis ability, migration, and invasion were analyzed by using 5‐ethynyl‐2′‐deoxyuridine (EdU) assay, flow cytometry, tube formation assay, transwell assay, and murine xenograft model, respectively. The target between miR‐1206 and circ_0043256 or Krüppel‐like factor 2 (KLF2) was verified by dual‐luciferase reporter assay. Results: Circ_0043256 was a stable circRNA, which was found to be decreased in lung cancer tissues and cells. Functionally, forced expression of circ_0043256 suppressed lung cancer cell growth, angiopoiesis, migration, and invasion. Mechanistically, circ_0043256 directly bound to miR‐1206 and miR‐1206 targeted KLF2, circ_0043256 could regulate KLF2 expression via absorbing miR‐1206. Rescue assay showed that miR‐1206 overexpression reversed the anticancer effects of circ_0043256 on lung cancer cells. Moreover, inhibition of miR‐1206 could suppress the malignant phenotypes of lung cancer cells, which was attenuated by KLF2 knockdown. Pre‐clinically, lentivirus‐mediated circ_0043256 overexpression impeded lung cancer growth in nude mice. Conclusion: Forced expression of circ_0043256 could impede the tumorigenesis of lung cancer via miR‐1206/KLF2 axis, indicating a potential therapeutic approach for lung cancer. [ABSTRACT FROM AUTHOR]

Background and Purpose: Senescent preadipocytes promote adipose tissue dysfunction by secreting pro‐inflammatory factors, although little is known about the mechanisms regulating their production. We investigated if up‐regulated purinoceptor function sensitizes senescent preadipocytes to cognate agonists and how such sensitization regulates inflammation. Experimental Approach: Etoposide was used to trigger senescence in 3T3‐L1 preadipocytes. CRISPR/Cas9 technology or pharmacology allowed studies of transcription factor function. Fura‐2 imaging was used for calcium measurements. Interleukin‐6 levels were quantified using quantitative PCR and ELISA. Specific agonists and antagonists supported studies of purinoceptor coupling to interleukin‐6 production. Experiments in MS1 VEGF angiosarcoma cells and adipose tissue samples from obese mice complemented preadipocyte experiments. Key Results: DNA damage‐induced senescence up‐regulated purinoceptor expression levels in preadipocytes and MS1 VEGF angiosarcoma cells. ATP‐evoked Ca2+ release was potentiated in senescent preadipocytes. ATP enhanced interleukin‐6 production, an effect mimicked by ADP but not UTP, in a calcium‐independent manner. Senescence‐associated up‐regulation and activation of the adenosine A3 receptor also enhanced interleukin‐6 production. However, nucleotide hydrolysis was not essential because exposure to ATPγS also enhanced interleukin‐6 secretion. Pharmacological experiments suggested coupling of P2X ion channels and P2Y12–P2Y13 receptors to downstream interleukin‐6 production. Interleukin‐6 signalling exacerbated inflammation during senescence and compromised adipogenesis. Conclusions and Implications: We report a previously uncharacterized link between cellular senescence and purinergic signalling in preadipocytes and endothelial cancer cells, raising the possibility that up‐regulated purinoceptors play key modulatory roles in senescence‐associated conditions like obesity and cancer. There is potential for exploitation of specific purinoceptor antagonists as therapeutics in inflammatory disorders. [ABSTRACT FROM AUTHOR]

Tripartite motif‐containing protein 27 (TRIM27/also called RFP) is a multifunctional ubiquitin E3 ligase involved in numerous cellular functions, such as proliferation, apoptosis, regulation of the NF‐kB pathway, endosomal recycling and the innate immune response. TRIM27 interacts directly with TANK‐binding kinase 1 (TBK1) and regulates its stability. TBK1 in complex with autophagy receptors is recruited to ubiquitin chains assembled on the mitochondrial outer membrane promoting mitophagy. Here, we identify TRIM27 as an autophagy substrate, depending on ATG7, ATG9 and autophagy receptors for its lysosomal degradation. We show that TRIM27 forms ubiquitylated cytoplasmic bodies that co‐localize with autophagy receptors. Surprisingly, we observed that induced expression of EGFP‐TRIM27 in HEK293 FlpIn TRIM27 knockout cells mediates mitochondrial clustering. TRIM27 interacts with autophagy receptor SQSTM1/p62, and the TRIM27‐mediated mitochondrial clustering is facilitated by SQSTM/p62. We show that phosphorylated TBK1 is recruited to the clustered mitochondria. Moreover, induced mitophagy activity is reduced in HEK293 FlpIn TRIM27 knockout cells, while re‐introduction of EGFP‐TRIM27 completely restores the mitophagy activity. Inhibition of TBK1 reduces mitophagy in HEK293 FlpIn cells and in the reconstituted EGFP‐TRIM27‐expressing cells, but not in HEK293 FlpIn TRIM27 knockout cells. Altogether, these data reveal novel roles for TRIM27 in mitophagy, facilitating mitochondrial clustering via SQSTM1/p62 and mitophagy via stabilization of phosphorylated TBK1 on mitochondria. [ABSTRACT FROM AUTHOR]