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Cell nucleus status decides the activities of corresponding cells, making its rapid and effective staining important for revealing the actual condition of biological environment in life science and related fields. In this study, fast staining of cell nucleus is realized by fluorescent carbon nanodots (CDs). The staining mechanism is due to the positively charged CD surface-induced cell membrane penetration, which facilitates the CD-nucleus binding via electrostatic attraction. The size of cell nucleus is easily measured with fluorescence imaging technique. In addition, the CD-based cell nucleus stain is applied for discriminating the normal and cancer cells by determining the cell-to-nucleus ratio with fluorescence images. [ABSTRACT FROM AUTHOR]

The plasma membrane forms the boundary between a living entity and its environment and acts as a barrier to permeation and flow of substances. Several computational means of calculating permeability have been implemented for molecular dynamics (MD) simulations-based approaches. Except for double bilayer systems, most permeability studies have been performed under equilibrium conditions, in large part due to the challenges associated with creating concentration gradients in simulations utilizing periodic boundary conditions. To enhance the scientific understanding of permeation and complement the existing computational means of characterizing membrane permeability, we developed a non-equilibrium method that enables the generation and maintenance of steady-state gradients in MD simulations. We utilize PBCs advantageously by imposing a directional bias to the motion of permeants so that their crossing of the boundary replenishes the gradient, like a previous study on ions. Under these conditions, a net flow of permeants across membranes may be observed to determine bulk permeability by a direct application of J = P Δ c . In the present study, we explore the results of its application to an exemplary O 2 and POPC bilayer system, demonstrating accurate and precise permeability measurements. In addition, we illustrate the impact of permeant concentration and the choice of thermostat on the permeability. Moreover, we demonstrate that energetics of permeation can be closely examined by the dissipation of the gradient across the membrane to gain nuanced insights into the thermodynamics of permeability. [ABSTRACT FROM AUTHOR]

Water cycling across the membrane transporters is considered a hallmark of cellular metabolism and it could be of high diagnostic relevance in the characterization of tumors and other diseases. The method relies on the response of intracellular proton exchanging molecules to the presence of extracellular Gd‐based contrast agents (GBCAs). Paramagnetic GBCAs enhances the relaxation rate of water molecules in the extracellular compartment and, through membrane exchange, the relaxation enhancement is transferred to intracellular molecules. The effect is detected at the MRI‐CEST (Magnetic Resonance Imaging ‐ Chemical Exchange Saturation Transfer) signal of intracellular proton exchanging molecules. The magnitude of the change in the CEST response reports on water cycling across the membrane. The method has been tested on Red Blood Cells and on orthotopic murine models of breast cancer with different degree of malignancy (4T1, TS/A and 168FARN). The distribution of voxels reporting on membrane permeability fits well with the cells' aggressiveness and acts as an early reporter to monitor therapeutic treatments. [ABSTRACT FROM AUTHOR]

Water cycling across the membrane transporters is considered a hallmark of cellular metabolism and it could be of high diagnostic relevance in the characterization of tumors and other diseases. The method relies on the response of intracellular proton exchanging molecules to the presence of extracellular Gd‐based contrast agents (GBCAs). Paramagnetic GBCAs enhances the relaxation rate of water molecules in the extracellular compartment and, through membrane exchange, the relaxation enhancement is transferred to intracellular molecules. The effect is detected at the MRI‐CEST (Magnetic Resonance Imaging ‐ Chemical Exchange Saturation Transfer) signal of intracellular proton exchanging molecules. The magnitude of the change in the CEST response reports on water cycling across the membrane. The method has been tested on Red Blood Cells and on orthotopic murine models of breast cancer with different degree of malignancy (4T1, TS/A and 168FARN). The distribution of voxels reporting on membrane permeability fits well with the cells' aggressiveness and acts as an early reporter to monitor therapeutic treatments. [ABSTRACT FROM AUTHOR]

The aquaporin‐4 (AQP4) water channel is abundantly expressed in the glial cells of the central nervous system and facilitates brain swelling following diverse insults, such as traumatic injury or stroke. Lack of specific and therapeutic AQP4 inhibitors highlights the need to explore alternative routes to control the water permeability of glial cell membranes. The cell surface abundance of AQP4 in mammalian cells fluctuates rapidly in response to changes in oxygen levels and tonicity, suggesting a role for vesicular trafficking in its translocation to and from the cell surface. However, the molecular mechanisms of AQP4 trafficking are not fully elucidated. In this work, early and recycling endosomes were investigated as likely candidates of rapid AQP4 translocation together with changes in cytoskeletal dynamics. In transiently transfected HEK293 cells a significant amount of AQP‐eGFP colocalised with mCherry‐Rab5‐positive early endosomes and mCherry‐Rab11‐positive recycling endosomes. When exposed to hypotonic conditions, AQP4‐eGFP rapidly translocated from intracellular vesicles to the cell surface. Co‐expression of dominant negative forms of the mCherry‐Rab5 and ‐Rab11 with AQP4‐eGFP prevented hypotonicity‐induced AQP4‐eGFP trafficking and led to concentration at the cell surface or intracellular vesicles respectively. Use of endocytosis inhibiting drugs indicated that AQP4 internalisation was dynamin‐dependent. Cytoskeleton dynamics‐modifying drugs also affected AQP4 translocation to and from the cell surface. AQP4 trafficking mechanisms were validated in primary human astrocytes, which express high levels of endogenous AQP4. The results highlight the role of early and recycling endosomes and cytoskeletal dynamics in AQP4 translocation in response to hypotonic and hypoxic stress and suggest continuous cycling of AQP4 between intracellular vesicles and the cell surface under physiological conditions. [ABSTRACT FROM AUTHOR]

The osmotic stress imposed on microorganisms by hypotonic conditions is perceived to regulate water and solute flux via cell membranes, which are crucial for survival. Some cells that fail to perceive osmotic stress die because this results in the rupture of the cell membrane. The flux through the membrane is characterized by the membrane permeability, which is measured using a stopped-flow apparatus in response to a millisecond-order osmolarity change. However, the obtained data are an ensemble average of each cell response. Additionally, the measurement of permeability, considering cellular viability, contributes to a more accurate evaluation of osmoadaptation. Here, we present a novel on-chip instantaneous extracellular solution exchange method using an air–liquid interface. The presented method provides a concurrent evaluation at the single-cell level in response to a millisecond-order osmotic shock, considering cellular viability by solution exchange. This method utilizes a liquid bridge with a locally formed droplet on the surface of a micropillar fabricated inside a microchannel. We evaluated a solution exchange time of 3.6 ms and applied this method to Synechocystis PCC 6803 under two different osmolarity conditions. The live/dead ratio of 1 M to 0.5 M osmotic down shock condition was 78.8/21.2% while that of 1 M to 0.25 M osmotic down shock condition was 40.0/60.0%. We evaluated the water permeability of two groups: cells that were still live before and after osmotic shock (hereafter named cell type 1), and cells that were live before but were dead 10 minutes after osmotic shock (hereafter named cell type 2). The results indicated that the water permeability of cell type 2 was higher than that of cell type 1. The results obtained using the presented methods confirmed that the effect of osmotic stress can be accurately evaluated using single-cell analysis. [ABSTRACT FROM AUTHOR]

This study was aimed to develop an efficient tumour-targeted liposome nanobubbles (LNBs) system using ultrasound-targeted nanobubble destruction for enhanced release and transfection of miRNA-199a-3p in hepatocellular carcinoma (HCC) therapy. The prepared LNBs comprised a polyethylene glycol-modified liposome shell and a perfluoropentane (PFP) core. MiRNA-199a-3p was attached to the nanocomposite surface via electrostatic adsorption, while RGD peptide functionalized the LNBs surface for enhanced HCC cell targeting, namely PFP@miR-RGD-LNBs. The LNBs were spherical with a narrow size distribution. The gene-loaded LNBs effectively condensed miR-199a-3p and protected it from enzymatic degradation. Low-intensity focused ultrasound (LIFU) promoted a fast release of miR-199a-3p from the prepared LNBs, thereby enhancing therapeutic effects. The combined application of PFP@miR-RGD-LNBs and LIFU exhibited a more potent inhibitory effect on HepG2 cells than the other groups, potentially due to LIFU promoting rapid and efficient gene release at the target site and increasing cell membrane permeability. Quantitative reverse transcription-polymerase chain reaction analysis revealed significantly increased mRNA expression levels of key apoptosis markers (Bad, Bax, Caspase-9 and Caspase-3) in the PFP@miR-RGD-LNBsþLIFU group compared to other groups. These findings suggest that the prepared LNBs are highly likely to be promising candidates for further exploration of HCC gene delivery and therapy. [ABSTRACT FROM AUTHOR]

Background: Caveolin-1 (Cav-1) is a pivotal protein in the plasma membrane. Studies on homozygous Cav-1 deficient mice revealed that Cav-1 is essential for endothelial function and angiogenesis in the retina. However, whether a reduction in Cav-1 content hampers the neurovascular unit (NVU) in the retina is unclear. Thus, this study examines the NVU in the retinas of heterozygous Cav-1 deficient (Cav-1+/−) mice and analyzes possible underlying mechanisms. Methods: The vascular, glial and neuronal components in the retina were evaluated using retinal morphometry, whole mount retinal immunofluorescence staining, histological analysis and optical coherence tomography. In addition, immunoblotting and immunofluorescence staining, subcellular fractionation, biotin labeling of cell surface proteins, and proximity ligation assay were employed to detect expression and localization of proteins in the retina or endothelial cells (ECs) upon knockdown of Cav-1 with Cav-1 siRNA. Results: Cav-1+/− retinas showed a significant reduction in pericyte coverage along with an increase in acellular capillaries compared to controls at 8 months of age, but not at 1 month. A significant loss and obvious morphological abnormalities of smooth muscle cells were observed in 8-month-old Cav-1+/− retinal arterioles. Macroglial and microglial cells were activated in the Cav-1+/− retinas. A transient significant delay in retinal angiogenesis was detected in Cav-1+/− retinas at p5, which was however no longer detectable at p10. The Cav-1+/− retinas displayed increased vascular permeability and a notable reduction in VEGFR2 content at 8 months. In vitro, siRNA-mediated knockdown experiments in ECs revealed that the loss of Cav-1 in ECs resulted in decreased levels of VEGFR2, VE-Cadherin and their interaction at the plasma membrane as well. Conclusion: Our results indicate that a sufficient Cav-1 level over 50% of its normal abundance is vital for the proper localization of VEGFR2 and VE-cadherin, likely in a complex, at the plasma membrane, which is essential for the maintenance of normal NVU in the retina. [ABSTRACT FROM AUTHOR]

The intrinsic pathway of apoptosis is regulated by the Bcl-2 family of proteins. Inhibition of the anti-apoptotic members represents a strategy to induce apoptotic cell death in cancer cells. We have measured the membrane binding properties of a series of peptides, including modified α/β-peptides, designed to exhibit enhanced membrane permeability to allow cell entry and improved access for engagement of Bcl-2 family members. The peptide cargo is based on the pro-apoptotic protein Bim, which interacts with all anti-apoptotic proteins to initiate apoptosis. The α/β-peptides contained cyclic β-amino acid residues designed to increase their stability and membrane permeability. Dual polarisation interferometry was used to study the binding of each peptide to two different model membrane systems designed to mimic either the plasma membrane or the outer mitochondrial membrane. The impact of each peptide on the model membrane structure was also investigated, and the results demonstrated that the modified peptides had increased affinity for the mitochondrial membrane and significantly altered the structure of the bilayer. The results also showed that the presence of an RRR motif significantly enhanced the ability of the peptides to bind to and insert into the mitochondrial membrane mimic, and provide insights into the role of selective membrane targeting of peptides. The membrane binding of two peptides designed to exhibit enhanced membrane permeability to allow cell entry and engagement of Bcl-2 family members shows that an RRR motif significantly enhances peptide binding and insertion into a mitochondrial membrane mimic and provides insights into selective membrane targeting of peptides. [ABSTRACT FROM AUTHOR]

The lipid molecule phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] controls all aspects of plasma membrane (PM) function in animal cells, from its selective permeability to the attachment of the cytoskeleton. Although disruption of PI(4,5)P2 is associated with a wide range of diseases, it remains unclear how cells sense and maintain PI(4,5)P2 levels to support various cell functions. Here, we show that the PIP4K family of enzymes, which synthesize PI(4,5)P2 via a minor pathway, also function as sensors of tonic PI(4,5)P2 levels. PIP4Ks are recruited to the PM by elevated PI(4,5)P2 levels, where they inhibit the major PI(4,5)P2-synthesizing PIP5Ks. Perturbation of this simple homeostatic mechanism reveals differential sensitivity of PI(4,5)P2-dependent signaling to elevated PI(4,5)P2 levels. These findings reveal that a subset of PI(4,5)P2-driven functions might drive disease associated with disrupted PI(4,5)P2 homeostasis. [ABSTRACT FROM AUTHOR]

The canonical autophagy pathway in mammalian cells sequesters diverse cytoplasmic cargo within the double membrane autophagosomes that eventually convert into degradative compartments via fusion with endolysosomal intermediates. Here, we report that autophagosomal membranes show permeability in cells lacking principal ATG8 proteins (mATG8s) and are unable to mature into autolysosomes. Using a combination of methods including a novel in vitro assay to measure membrane sealing, we uncovered a previously unappreciated function of mATG8s to maintain autophagosomal membranes in a sealed state. The mATG8 proteins GABARAP and LC3A bind to key ESCRT‐I components contributing, along with other ESCRTs, to the integrity and imperviousness of autophagic membranes. Autophagic organelles in cells lacking mATG8s are permeant, are arrested as amphisomes, and do not progress to functional autolysosomes. Thus, autophagosomal organelles need to be maintained in a sealed state in order to become lytic autolysosomes. Synopsis: Mammalian ATG8s (mATG8s) interact with ESCRT‐I components to maintain autophagosomal membranes in a sealed, nonporous state that enables autophagic intermediates to progress into lytic organelles. mATG8s bind and recruit ESCRT components to maintain autophagic membranes in a sealed state impermeable to solutesBoth LC3 and GABARP subsets of mATG8s are requiredThe most widely used marker of autophagy, LC3B, is not involved in these processesAutophagic organelles not maintained in a sealed state are arrested at the amphisomal stage [ABSTRACT FROM AUTHOR]

Objectives: Tight junctions (TJs) are involved in the regulation of salivary secretion via paracellular pathway. Botulinum toxin type A (BTXA) is widely used for the treatment of hypersecretion diseases such as sialorrhea. This study aimed to investigate the role of TJs in BTXA‐inhibited secretion of the submandibular gland (SMG). Materials and Methods: BTXA was injected into the SMGs of rats, and the same amount of saline was injected as a control. Western blot, real‐time PCR, and immunofluorescence staining were used to detect the expression and distribution of TJ proteins. Paracellular permeability was evaluated using the transepithelial electrical resistance (TER) measurements and fluorescent tracer detection in BTXA‐stimulated SMG‐C6 cells. Results: BTXA injection into the SMGs of rats led to increased expression of claudin (Cldn) −1 and Cldn3. Immunofluorescence staining showed no significant changes in the distribution of TJ proteins. In vitro, BTXA increased the TER values and significantly reduced the permeability of fluorescent tracer, suggesting that BTXA decreased the paracellular permeability. The expression levels of Cldn1, Cldn3, and Cldn4 were upregulated after BTXA treatment. Conclusion: The expression of TJ proteins changed in both animal models and SMG‐C6 cells after BTXA treatment, which may contribute to the inhibition of salivary secretion. [ABSTRACT FROM AUTHOR]

Methods to follow in real time complex processes occurring along living cell membranes such as cell permeabilization are rare. Here, the terahertz spectroscopy reveals early events in plasma membrane alteration generated during photodynamic therapy (PDT) protocol, events which are not observable in any other conventional biological techniques performed in parallel as comparison. Photodynamic process is examined in Madin‐Darby canine kidney cells using Pheophorbide (Pheo) photosensitizer alone or alternatively encapsulated in poly(ethylene oxide)‐block‐poly(ε‐caprolactone) micelles for drug delivery purpose. Terahertz spectroscopy (THz) reveals that plasma membrane permeabilization starts simultaneously with illumination and is stronger when photosensitizer is encapsulated. In parallel, the exchange of biological species is assessed. Over several hours, this conventional approach demonstrates significant differences between free and encapsulated Pheo, the latter leading to high penetration of propidium iodide, Na+ and Ca2+ ions, and a high level of leakage of K+, ATP, and lactate dehydrogenase. THz spectroscopy provides, in a single measurement, the relative number of defects per membrane surface created after PDT, which is not achieved by any other method, providing early, sensitive real‐time information. THz spectroscopy is therefore a promising technique and can be applied to any biological topic requiring the examination of short‐term plasma membrane permeabilization. [ABSTRACT FROM AUTHOR]

The effect of carbon dots (CDs) on a model blayer membrane was studied as a means of comprehending their ability to affect cell membranes. Initially, the interaction of N-doped carbon dots with a biophysical liposomal cell membrane model was investigated by dynamic light scattering, z-potential, temperature-modulated differential scanning calorimetry, and membrane permeability. CDs with a slightly positive charge interacted with the surface of the negative-charged liposomes and evidence indicated that the association of CDs with the membrane affects the structural and thermodynamic properties of the bilayer; most importantly, it enhances the bilayer's permeability against doxorubicin, a well-known anticancer drug. The results, like those of similar studies that surveyed the interaction of proteins with lipid membranes, suggest that carbon dots are partially embedded in the bilayer. In vitro experiments employing breast cancer cell lines and human healthy dermal cells corroborated the findings, as it was shown that the presence of CDs in the culture medium selectively enhanced cell internalization of doxorubicin and, subsequently, increased its cytotoxicity, acting as a drug sensitizer. [ABSTRACT FROM AUTHOR]

Primary human bronchial epithelial cultures (HBECs) are used to study airway physiology, disease, and drug development. HBECs often replicate human airway physiology/pathophysiology. Indeed, in the search for cystic fibrosis (CF) transmembrane conductance regulator (CFTR) therapies, HBECs were seen as the "gold standard" in preclinical studies. However, HBECs are not without their limitations: they are non-immortalized and the requirement for human donors, especially those with rare genetic mutations, can make HBECs expensive and/or difficult to source. For these reasons, researchers may opt to expand HBECs by passaging. This practice is common, but to date, there has not been a robust analysis of the impact of expanding HBECs on their phenotype. Here, we used functional studies of airway surface liquid (ASL) homeostasis, epithelial barrier properties, and RNA-seq and Western blotting to investigate HBEC changes over two passage cycles. We found that passaging impaired CFTR-mediated ASL secretion and led to a reduction in the plasma membrane expression of the epithelial sodium channel (ENaC) and CFTR. Passaging also resulted in an increase in transepithelial resistance and a decrease in epithelial water permeability. We then looked for changes at the mRNA level and found that passaging significantly affected 323 genes, including genes involved in inflammation, cell growth, and extracellular matrix remodeling. Collectively, these data highlight the potential for HBEC expansion to impact research findings. [ABSTRACT FROM AUTHOR]

Glucose is widely used as an osmotic agent in fluids for peritoneal dialysis. The aim of this work was to study the effect of glucose on the expression of the aquaporin-1 (AQP1) water channel and TonEBP transcription factor, as well as on plasma membrane water permeability of cells in the primary culture of Wistar rat mesenteric mesotheliocytes, using fluorescence microscopy with the intracellular fluorescent dye сalcein. mRNA contents were assessed by real time RT-PCR. Preincubation of cells in a DMEM medium containing glucose (2.3%, 24 h, 37°C, 5% CO2) led to a decrease in the expression of the aqp1 gene by about 60% (control 0.87 ± 0.18; glucose 0.34 ± 0.12, n = 9, p < 0.05) and the tonebp gene by 20% (control 0.37 ± 0.024; glucose 0.3 ± 0.012, n = 9, p < 0.05). A 40% decrease in plasma membrane water permeability of peritoneal mesotheliocytes was also observed after 24-h preincubation with glucose (control 7.3E-3 ± 1.3E-3 (cm/s), n = 27; glucose 4.3E-3 ± 3.8E-4 (cm/s), n = 57, p < 0.01). These results indicate that glucose can exert an inhibitory effect on transport processes in peritoneal mesothelial cells, which, under multiple exposures, may result in structural and functional disorders of the peritoneal membrane. [ABSTRACT FROM AUTHOR]

Different types of natural K+ channels share similar core modules and cation permeability characteristics. In this study, we have developed novel artificial K+ channels by rebuilding the core modules of natural K+ channels in artificial systems. All the channels displayed high selectivity for K+ over Na+ and exhibited a selectivity sequence of K+≈Rb+ during the transport process, which is highly consistent with the cation permeability characteristics of natural K+ channels. More importantly, these artificial channels could be efficiently inserted into cell membranes and mediate the transmembrane transport of K+, disrupting the cellular K+ homeostasis and eventually triggering the apoptosis of cells. These findings demonstrate that, by rebuilding the core modules of natural K+ channels in artificial systems, the structures, transport behaviors, and physiological functions of natural K+ channels can be mimicked in synthetic channels. [ABSTRACT FROM AUTHOR]

Different types of natural K+ channels share similar core modules and cation permeability characteristics. In this study, we have developed novel artificial K+ channels by rebuilding the core modules of natural K+ channels in artificial systems. All the channels displayed high selectivity for K+ over Na+ and exhibited a selectivity sequence of K+≈Rb+ during the transport process, which is highly consistent with the cation permeability characteristics of natural K+ channels. More importantly, these artificial channels could be efficiently inserted into cell membranes and mediate the transmembrane transport of K+, disrupting the cellular K+ homeostasis and eventually triggering the apoptosis of cells. These findings demonstrate that, by rebuilding the core modules of natural K+ channels in artificial systems, the structures, transport behaviors, and physiological functions of natural K+ channels can be mimicked in synthetic channels. [ABSTRACT FROM AUTHOR]

Permeability across cellular membranes is a key factor that influences absorption and distribution. Before absorption, many drugs must pass through the mucus barrier that covers all the wet surfaces of the human body. Cell-free in vitro tools currently used to evaluate permeability fail to effectively model the complexity of mucosal barriers. Here, we present an in vitro mucosal platform as a possible strategy for assessing permeability in a high-throughput setup. The PermeaPad 96-well plate was used as a permeability system and further coupled to a pathological, tridimensional mucus model. The physicochemical determinants predicting passive diffusion were determined by combining experimental and computational approaches. Drug solubility, size, and shape were found to be the critical properties governing permeability, while the charge of the drug was found to be influential on the interaction with mucus. Overall, the proposed mucosal platform could be a promising in vitro tool to model the complexity of mucosal tissues and could therefore be adopted for drug-permeability profiling. [ABSTRACT FROM AUTHOR]

Simple Summary: Renal cell carcinoma (RCC) has an extremely poor prognosis, as there are few therapeutic options. In addition, resistance often develops during the administration of cytostatic drugs, preventing further drug-based therapy. New therapeutic modalities to reduce tumor cells would therefore be an important advance in the cancer therapy of RCC. In the present research study, non-invasive physical plasma (NIPP) was used to treat RCC cells. It was found that both cell growth and cell motility of RCC cells could be significantly reduced. Furthermore, programmed cell death was induced, so that some of the cancer cells actually died. Cellular analysis of NIPP treated cancer cells indicated that exposure to NIPP resulted in increased permeability of the cytoplasmic membrane to low molecular weight substances. This may contribute to the inhibition of the physiological activities of the cancer cells. The present results suggest that treatment with NIPP may represent a promising, innovative, and non-chemical option for the therapy of RCC and cancer in general. In combination with established therapeutic modalities, therapeutic effects would be enhanced and resistance would be minimized by the simultaneous application of multiple modes of action. Renal cell carcinoma (RCC) is the third most common urological tumor and has an extremely poor prognosis after metastasis has occurred. Therapeutic options are highly restricted, primarily due to resistance to classical chemotherapeutics. The development of new, innovative therapeutic procedures is thus of great urgency. In the present study, the influence of non-invasive physical plasma (NIPP) on malignant and non-malignant renal cells is characterized. The biological efficacy of NIPP has been demonstrated in malignant renal cell lines (786-O, Caki-1) and non-malignant primary human renal epithelial cells (HREpC). The cell responses that were experimentally examined were cell growth (cell number determination, calculation of growth rate and doubling time), cell motility (scratch assay, invasiveness assay), membrane integrity (uptake of fluorescent dye, ATP release), and induction of apoptosis (TUNEL assay, caspase-3/7 assay, comet assay). A single NIPP treatment of the malignant cells significantly inhibited cell proliferation, invasiveness, and metastasis. This treatment has been attributed to the disruption of membrane functionality and the induction of apoptotic mechanisms. Comparison of NIPP sensitivity of malignant 786-O and Caki-1 cells with non-malignant HREpC cells showed significant differences. Our results suggest that renal cancer cells are significantly more sensitive to NIPP than non-malignant renal cells. Treatment with NIPP could represent a promising innovative option for the therapy of RCC and might supplement established treatment procedures. Of high clinical relevance would be the chemo-sensitizing properties of NIPP, which could potentially allow a combination of NIPP treatment with low-dose chemotherapy. [ABSTRACT FROM AUTHOR]

Decabromodiphenyl ether (BDE-209), a major component of brominated flame retardants, has been detected in considerable amounts in the soil. Given that BDE-209 is toxic, ubiquitous, and persistent, it may cause toxic effects on vegetables planted in contaminated soil. In this study, Chinese cabbage seedlings cultivated in the soil contaminated by BDE-209 (5 - 20 mg kg-1) for 60 d were investigated to evaluate the phytotoxicity of BDE-209 in terms of growth, physiological responses, photosynthetic function, and antioxidant capacity. The results showed that BDE-209-induced phytotoxicity was reflected in the growth suppression, the decrease of chlorophyll content and soluble protein content, and especially in the reduced photosynthetic parameters (net photosynthetic rate and stomatal conductance). BDE- 209 showed direct toxicities to plasma membranes causing their elevated permeability. In addition, BDE-209 induced the overproduction of reactive oxygen species (ROS), membrane lipid peroxidation and protein carbonylation, manifesting in the increased content of O2 •-, H2O2, malondialdehyde, and carbonyl. Chinese cabbage seedlings activated the antioxidant defence system (superoxide dismutase and peroxidase) to scavenge the ROS and counter-balance the oxidative stress caused by BDE-209, while the toxicity could not be effectively alleviated. Our study will provide valuable information for further understanding of the phytotoxicity of polybrominated diphenyl ethers. [ABSTRACT FROM AUTHOR]

Composite preparations based on rhamnolipid biosurfactants and N-containing heterocyclic 1,4-naphthoquinone derivatives were obtained. The formation of the compositions was confirmed by UV spectroscopy, dynamic light scattering and changes in the surface tension of the compositions in comparison with the original solutions. Physicochemical and biological properties of composite drugs have been studied. The anticonvulsant effect was assessed using the pentylenetetrazole (PTZ) model. Doses of PTZ for induction of clonictonic seizures (DCTC) and tonic extension (DTE) were calculated relative to control. The effect of rhamnolipid on increasing the permeability of cell membranes for compounds 1a-e was evaluated indirectly by studying anticonvulsant activity. Compound (2-chloro3-((3-(p-tolyl)-1H-pyrazol-5-yl)amino) naphthalene-1,4-dione) (1b) in combination with rhamnolipid was found to have a higher anticonvulsant activity DCTC and DTE averaged 239% and 244%, respectively, which may indicate an improvement of the penetration of the compound when in complex with rhamnolipid into the cell and as a result, an increased anticonvulsant activity of the composite drug. [ABSTRACT FROM AUTHOR]

Simple Summary: Most cases of differentiated thyroid carcinoma (DTC) are associated with a good prognosis. However, a significant number progress to advanced disease exhibiting aggressive clinical characteristics. These cases have a poorer prognosis because they become resistant to radioactive iodine (RAI) treatment. One of the causes for this resistance is the reduction of the channel responsible for iodide uptake (NIS—the sodium iodide symporter) at the plasma membrane (PM) of metastatic thyroid cancer cells. Here we describe that cell–cell adhesion is a key determinant for NIS residency at the PM, suggesting that loss of cell–cell adhesion during metastization contributes to RAI treatment resistance in advanced TC. Our findings indicate that successful resensitization therapies might require the use of agents that improve epithelial cell–cell adhesion in refractory TC cells. While most cases of differentiated thyroid carcinoma (DTC) are associated with a good prognosis, a significant number progress to advanced disease exhibiting aggressive clinical characteristics and often becoming refractory to radioactive iodine (RAI) treatment, the current gold-standard therapeutic option for metastatic disease. RAI-refractoriness is caused by defective functional expression of the sodium-iodide symporter (NIS), which is responsible for the active transport of iodide across the plasma membrane (PM) into thyroid follicles. NIS deficiency in these tumors often reflects a transcriptional impairment, but also its defective targeting and retention at the cells' PM. Using proteomics, we previously characterized an intracellular signaling pathway derived from SRC kinase that acts through the small GTPase RAC1 to recruit and bind the actin-anchoring adaptor EZRIN to NIS, regulating its retention at the PM of both non-transformed and cancer thyroid cells. Here, we describe how by reanalyzing the proteomics data, we identified cell–cell adhesion as the molecular event upstream the pathway involved in the anchoring and retention at the PM. We show that by interacting with NIS at the PM, adherens junction (AJ)-associated P120-catenin recruits and is phosphorylated by SRC, allowing it to recruit RAC1 to the complex. This enables SRC-phosphorylated VAV2 exchange factor to activate RAC1 GTPase, inducing NIS retention at the PM, thus increasing its abundance and function at the surface of thyroid cells. Our findings indicate that the loss of epithelial cell–cell adhesion may contribute to RAI refractoriness, indicating that in addition to stimulating NIS expression, successful resensitization therapies might require the employment of agents that improve cell–cell adhesion and NIS PM retention in refractory TC cells. [ABSTRACT FROM AUTHOR]

The plasma membrane (sarcolemma) of skeletal muscle myofibers is susceptible to injury caused by physical and chemical stresses during normal daily movement and/or under disease conditions. These acute plasma membrane disruptions are normally compensated by an intrinsic membrane resealing process involving interactions of multiple intracellular proteins including dysferlin, annexin, caveolin, and Mitsugumin 53 (MG53)/TRIM72. There is new evidence for compromised muscle sarcolemma repair mechanisms in Amyotrophic Lateral Sclerosis (ALS). Mitochondrial dysfunction in proximity to neuromuscular junctions (NMJs) increases oxidative stress, triggering MG53 aggregation and loss of its function. Compromised membrane repair further worsens sarcolemma fragility and amplifies oxidative stress in a vicious cycle. This article is to review existing literature supporting the concept that ALS is a disease of oxidative-stress induced disruption of muscle membrane repair that compromise the integrity of the NMJs and hence augmenting muscle membrane repair mechanisms could represent a viable therapeutic strategy for ALS. [ABSTRACT FROM AUTHOR]

Some aquaporins (AQPs) allow the diffusion of hydrogen peroxide (H2O2), the most abundant ROS, through the cell membranes. Therefore, the possibility of regulating the AQP-mediated permeability to H2O2, and thus ROS scavenging, appears particularly important for controlling the redox state of cells in physiological and pathophysiological conditions. Several compounds have been screened and characterized for this purpose. This study aimed to analyze the effect of cerium oxide nanoparticles (CNPs) presenting antioxidant activity on AQP functioning. HeLa cells express AQP3, 6, 8, and 11, able to facilitate H2O2. AQP3, 6, and 8 are expressed in the plasma membrane and intracellularly, while AQP11 resides only in intracellular structures. CNPs but not cerium ions treatment significantly increased the water and H2O2 permeability by interacting with AQP3, 6, and especially with AQP8. CNPs increased considerably the AQP-mediated water diffusion in cells with oxidative stress. Functional experiments with silenced HeLa cells revealed that CNPs increased the H2O2 diffusion mainly by modulating the AQP8 permeability but also the AQP3 and AQP6, even if to a lesser extent. Current findings suggest that CNPs represent a promising pharmaceutical agent that might potentially be used in numerous pathologies involving oxidative stress as tumors and neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Peanut sprout (longevity sprout) is one kind of favored food and therapy, due to its crisp taste and unique flavor. The energy, protein, and crude fat content of peanut buds after germination is significantly higher than that of various vegetables. There is a great increase in the content of vitamins, potassium, magnesium minerals, and various amino acids and trace elements required by the human body, especially the content of resveratrol, a polyphenol with important bioactive functions. Among them, resveratrol (chemically known as 3, 4', 5-astragalotriphenol) has the broad-spectrum antibacterial activity as the "plant antitoxin" in recent years. But, there are only a few reports on the effects of peanut bud resveratrol on Salmonella typhimurium. This study was focused on the isolation and purification technique of resveratrol from peanut buds, together with its antibacterial properties. The resins were screened with excellent adsorption and desorption properties for the peanut bud resveratrol compounds, in order to construct the isolation and purification process. The antibacterial efficacy was evaluated to improve the comprehensive utilization of peanut resources. A comparison was made to determine the effects of 16 types of macroporous resins on the separation and purification of arachidonic resveratrol compounds using static adsorption-desorption tests. The LSA-40 was selected as the best adsorption resin for the saturation and plateau in 110 and 90min of static adsorption, respectively. The dynamic adsorption-desorption conditions were optimized as follows. The loading concentration was 120.00 μg/mL, the flow rate was 1.00 mL/min, the pH value was 4.2, and the optimum ratio of loading volume to resin was 8.00 mL/g. The desorption conditions were the 80% ethanol solution, a pH value of 6.6, and a flow rate of 1.00 mL/min. Ultraviolet (UV) spectral analysis showed that the absorption peaks of the purified arachidonic resveratrol and the control were basically the same under the optimized process conditions, where the purity was calculated to be 84.0%. Fourier infrared spectroscopy and ultra-performance liquid chromatography-tandem mass spectrometry were used to identify the components of the purified samples. It was found that the main components of the purified products were resveratrol and the derivatives. The inhibition effect of the purified product on Salmonella typhimurium was evaluated by multiplicative dilution, inhibition growth curve, and cell membrane permeability. The minimum inhibitory concentration of resveratrol-purified product on Salmonella typhimurium was 250 μg/mL. In addition, Salmonella typhimurium treated with resveratrol purification presented a prolonged lag period and a decreased growth rate in the logarithmic phase at the MIC concentration. The cell membrane permeability significantly increased (P < 0.01), according to the growth curve and the protein content of cell contents. The integrity of the cell wall was damaged causing the serious leakage of intracellular proteins, eventually leading to the death of Salmonella typhimurium. This finding can provide some theoretical reference for the comprehensive utilization of peanut resources in natural antibacterial agents. [ABSTRACT FROM AUTHOR]

• Heterogeneous multiscale modelling of drug delivery in biological tissues considering the cell membrane permeability. • A permeable interface method based on the central-type finite difference discretization is developed. • Lower solute permeability of the cell membrane decreases the drug penetration. • Drug penetration can be increased with the specific choice of cell shape irrespective of the cell membrane permeability. • Drug penetration can vary with the cell shape even the tissue domain's porosity (ECM volume) remains unchanged. This article presents a finite volume heterogeneous multiscale method (FVHMM-p) to study drug delivery into biological tissues. The FVHMM-p accounts for the passive diffusion across the cell membrane, and the algorithm involves models at two scales: macroscale (tissue scale) and microscale (cell scale). The passive diffusion across membranes is treated in the microscale model which is apparently a three-compartment model; the first compartment involves solute diffusion in extracellular space, the second one includes diffusivity across the cell membrane, and the third one is meant for diffusion in the intracellular space. For the microscale model simulation, a permeable interface method based on central-type finite difference discretization is developed. This model is coupled with the tissue scale model to enforce the cellular (microscale) effects. Furthermore, the effects of cell membrane permeability and drug particle size on distribution and penetration of drug nanoparticles in tissues are investigated by conducting numerical experiments. The cell is considered to be elliptical, and the simulations with different configurations lead to the pronounced effects. The proposed model will be able to identify the optimal strategies in drug delivery. [ABSTRACT FROM AUTHOR]

• R-MnO2 electrodes were used in capacitive system to inactivate microbes successfully. • Bacterial membrane permeability and intracellular ROS levels increase significantly after 5 min capacitance treatment. • Capacitive system was applied as pretreatment for ozonation to reduce O3 dosage and DBPs. • The performance of capacitance-O3 process is proved better than the sum of two individual process efficiencies. • A clean and efficient sequential process was rationally designed for water disinfection. The application of ozone (O 3) disinfection has been hindered by its low solubility in water and the formation of disinfection by-products (DBPs). In this study, capacitive disinfection is applied as a pre-treatment for O 3 oxidation, in which manganese dioxide with a rambutan-like hollow spherical structure is used as the electrode to increase the charge density on the electrode surface. When a voltage is applied, the negative-charged microbes are attracted to the electrodes and killed by electrical interactions. The contact between microbes and capacitive electrodes leads to changes in cell permeability and burst of reactive oxygen species, thereby promoting the diffusion of O 3 into the cells. After O 3 penetrates the cell membrane, it can directly attack the cytoplasmic constituents, accelerating fatal and irreversible damage to pathogens. As a result, the performance of the capacitance-O 3 process is proved better than the direct sum of the two individual process efficiencies. The design of capacitance-O 3 system is beneficial to reduce the ozone dosage and DBPs with a broader inactivation spectrum, which is conducive to the application of ozone in primary water disinfection. [ABSTRACT FROM AUTHOR]

• UV222 suppressed photoreactivation of E. coli by 2-log compared with UV254. • UV222 disinfection damaged multiple cellular targets—DNA, protein, and the cell membrane. • UV222 induced DNA damage at fewer sites than UV254, but the damage was more severe. • UV222 damaged the E. coli cell membrane by photolyzing membrane lipid and protein. • UV222 photolyzed nucleic acid bases and amino acids. Low-pressure mercury lamps emitting at 254 nm (UV254) are used widely for disinfection. However, subsequent exposure to visible light results in photoreactivation of treated bacteria. This study employed a krypton chloride excimer lamp emitting at 222 nm (UV222) to inactivate E. coli. UV222 and UV254 treatment had similar E. coli -inactivation kinetics. Upon subsequent irradiation with visible light, E. coli inactivated by UV254 was reactivated from 2.71-log to 4.75-log, whereas E. coli inactivated by UV222 showed negligible photoreactivation. UV222 treatment irreversibly broke DNA strands in the bacterium, whereas UV254 treatment primarily formed nucleobase dimers. Additionally, UV222 treatment caused cell membrane damage, resulting in wizened, pitted cells and permeability changes. The damage to the cell membrane was mainly due to the photolysis of proteins and lipids by UV222. Furthermore, the photolysis of proteins by UV222 destroyed enzymes, which blocked photoreactivation and dark repair. The multiple damages can be further evidenced by 4.0–61.1 times higher quantum yield in the photolysis of nucleobases and amino acids for UV222 than UV254. This study demonstrates that UV222 treatment damages multiple sites in bacteria, leading to their inactivation. Employing UV222 treatment as an alternative to UV254 could be viable for inhibiting microorganism photoreactivation in water and wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

Listeria monocytogenes is a foodborne bacterial pathogen that seriously threatens dairy product safety and human health, hence effective and available antibacterial agents are urgently needed. This study aims to investigate the antibacterial mechanism of a recombinant enterocin CHQS against L. monocytogenes and its antibacterial effect on pasteurized milk. The minimum inhibitory concentration (MIC) of CHQS was 0.5 μg/mL in both TSB medium and tenfold diluted pasteurized milk. The anti- L. monocytogenes rate of 2 h reached 99.94% with the treatment of the 2 MIC of CHQS in the diluted pasteurized milk. CHQS led to the massive release of proteins and nucleic acids and the significant increase in propidium iodide (PI) uptake, indicating that integrity and permeability of the cell membrane were destroyed. The cell membrane and structure of L. monocytogenes were severely disrupted by observing with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Intracellular reactive oxygen species (ROS) level was increased to 2.18-fold with the 2 MIC CHQS treatment. CHQS at sub-MICs inhibited the biofilm formation and motility of L. monocytogenes in a concentration-dependent manner. In MIC treatment group, the number of L. monocytogenes was 4.55 log 10 CFU/mL fewer than the control group and the bacterial abundance of L. monocytogenes remained a low level (0.22%) on the 12th day of storage at 4 °C in pasteurized milk. The study suggested the antibacterial mechanism of CHQS and its application potentiality in pasteurized milk. • The antibacterial mechanism of a recombinant enterocin CHQS against L. monocytogenes was investigated. • The antibacterial effect of CHQS on pasteurized milk was explored. • CHQS inhibited L. monocytogenes growth by disrupting the integrity and permeability of cell membranes. • CHQS can stimulate ROS generation and inhibit the motility and biofilm formation of L. monocytogenes. [ABSTRACT FROM AUTHOR]

Animal models and clinical studies suggest an influence of angiotensin II (AngII) on the pathogenesis of liver diseases via the renin–angiotensin system. AngII application increases portal blood pressure, reduces bile flow, and increases permeability of liver tight junctions. Establishing the subcellular localization of angiotensin II receptor type 1 (AT1R), the main AngII receptor, helps to understand the effects of AngII on the liver. We localized AT1R in situ in human and porcine liver and porcine gallbladder by immunohistochemistry. In order to do so, we characterized commercial anti-AT1R antibodies regarding their capability to recognize heterologous human AT1R in immunocytochemistry and on western blots, and to detect AT1R using overlap studies and AT1R-specific blocking peptides. In hepatocytes and canals of Hering, AT1R displayed a tram-track-like distribution, while in cholangiocytes AT1R appeared in a honeycomb-like pattern; i.e., in liver epithelia, AT1R showed an equivalent distribution to that in the apical junctional network, which seals bile canaliculi and bile ducts along the blood–bile barrier. In intrahepatic blood vessels, AT1R was most prominent in the tunica media. We confirmed AT1R localization in situ to the plasma membrane domain, particularly between tight and adherens junctions in both human and porcine hepatocytes, cholangiocytes, and gallbladder epithelial cells using different anti-AT1R antibodies. Localization of AT1R at the junctional complex could explain previously reported AngII effects and predestines AT1R as a transmitter of tight junction permeability. [ABSTRACT FROM AUTHOR]

Ultrasound with low frequency (20–100 kHz) assisted drug delivery has been widely investigated as a non-invasive method to enhance the permeability and retention effect of drugs. The functional micro/nanobubble loaded with drugs could provide an unprecedented opportunity for targeted delivery. Then, ultrasound with higher intensity would locally burst bubbles and release agents, thus avoiding side effects associated with systemic administration. Furthermore, ultrasound-mediated destruction of micro/nanobubbles can effectively increase the permeability of vascular membranes and cell membranes, thereby not only increasing the distribution concentration of drugs in the interstitial space of target tissues but also promoting the penetration of drugs through cell membranes into the cytoplasm. These advancements have transformed ultrasound from a purely diagnostic utility into a promising theragnostic tool. In this review, we first discuss the structure and generation of micro/nanobubbles. Second, ultrasound parameters and mechanisms of therapeutic delivery are discussed. Third, potential biomedical applications of micro/nanobubble-assisted ultrasound are summarized. Finally, we discuss the challenges and future directions of ultrasound combined with micro/nanobubbles. [ABSTRACT FROM AUTHOR]

The main aim of this study was to determine and compare the antimicrobial effect of hibiscus acid and a commercial 0.12% (w/v) chlorhexidine mouthrinse against Streptococcus mutans, Streptococcus sanguinis, Capnocytophaga gingivalis, and Staphylococcus aureus, and to determine the effect on bacterial cell membrane permeability and the toxicity of hibiscus acid in a mouse model. Hibiscus acid was obtained from acetone extract of Hibiscus sabdariffa calyces. Chlorhexidine (0.12% w/v) mouthrinse was purchased from a local pharmacy. The antimicrobial activity of hibiscus acid and mouthrinse were determined using the gel diffusion technique. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the solutions were determined using the broth dilution method. The effect on bacterial cell membrane permeability of hibiscus acid and mouthrinse was determined by crystal violet assay. The toxicity of hibiscus acid was investigated in a mouse model (registration number: UAEH2019-A1-S-8288). Hibiscus acid and mouthrinse showed antibacterial activity against all oral pathogenic bacteria. However, hibiscus acid showed a lower antibacterial effect compared with chlorhexidine mouthrinse. The MIC and MBC for hibiscus acid were 3 and 5 mg/mL, respectively, and was between 30 and 50 μg/mL for mouthrinse. The crystal violet test results indicate that hibiscus acid and mouthrinse alter the permeability of the bacterial membrane. Finally, hibiscus acid did not show toxicity in mouse studies. [ABSTRACT FROM AUTHOR]

Background: Traumatic brain injury (TBI) remains one of the main causes for disability and death worldwide. While the primary mechanical injury cannot be avoided, the prevention of secondary injury is the focus of TBI research. Present study aimed to elucidate the effects and mechanisms of S100B and its receptor RAGE on mediating secondary injury after TBI.Methods: This study established TBI animal model by fluid percussion injury in rats, cell model by stretch-injured in astrocytes, and endothelial injury model with conditioned medium stimulation. Pharmacological intervention was applied to interfere the activities of S100B/RAGE/ADAM17 signaling pathway, respectively. The expressions or contents of S100B, RAGE, syndecan-1 and ADAM17 in brain and serum, as well as in cultured cells and medium, were detected by western blot. The distribution of relative molecules was observed with immunofluorescence.Results: We found that TBI could activate the release of S100B, mostly from astrocytes, and S100B and RAGE could mutually regulate their expression and activation. Most importantly, present study revealed an obvious increase of syndecan-1 in rat serum or in endothelial cultured medium after injury, and a significant decrease in tissue and in cultured endothelial cells, indicating TBI-induced shedding of endothelial glycocalyx. The data further proved that the activation of S100B/RAGE signaling could promote the shedding of endothelial glycocalyx by enhancing the expression, translocation and activity of ADAM17, an important sheddase, in endothelial cells. The damage of endothelial glycocalyx consequently aggravated blood brain barrier (BBB) dysfunction and systemic vascular hyper-permeability, overall resulting in secondary brain and lung injury.Conclusions: TBI triggers the activation of S100B/RAGE signal pathway. The regulation S100B/RAGE on ADAM17 expression, translocation and activation further promotes the shedding of endothelial glycocalyx, aggravates the dysfunction of BBB, and increases the vascular permeability, leading to secondary brain and lung injury. Present study may open a new corridor for the more in-depth understanding of the molecular processes responsible for cerebral and systemic vascular barrier impairment and secondary injury after TBI. [ABSTRACT FROM AUTHOR]

The Pseudomonas aeruginosa toxin ExoS, secreted by the type III secretion system (T3SS), supports intracellular persistence via its ADP-ribosyltransferase (ADPr) activity. For epithelial cells, this involves inhibiting vacuole acidification, promoting vacuolar escape, countering autophagy, and niche construction in the cytoplasm and within plasma membrane blebs. Paradoxically, ExoS and other P. aeruginosa T3SS effectors can also have antiphagocytic and cytotoxic activities. Here, we sought to reconcile these apparently contradictory activities of ExoS by studying the relationships between intracellular persistence and host epithelial cell death. Methods involved quantitative imaging and the use of antibiotics that vary in host cell membrane permeability to selectively kill intracellular and extracellular populations after invasion. Results showed that intracellular P. aeruginosa mutants lacking T3SS effector toxins could kill (permeabilize) cells when extracellular bacteria were eliminated. Surprisingly, wild-type strain PAO1 (encoding ExoS, ExoT and ExoY) caused cell death more slowly, the time extended from 5.2 to 9.5 h for corneal epithelial cells and from 10.2 to 13.0 h for HeLa cells. Use of specific mutants/complementation and controls for initial invasion showed that ExoS ADPr activity delayed cell death. Triggering T3SS expression only after bacteria invaded cells using rhamnose-induction in T3SS mutants rescued the ExoS-dependent intracellular phenotype, showing that injected effectors from extracellular bacteria were not required. The ADPr activity of ExoS was further found to support internalization by countering the antiphagocytic activity of both the ExoS and ExoT RhoGAP domains. Together, these results show two additional roles for ExoS ADPr activity in supporting the intracellular lifestyle of P. aeruginosa; suppression of host cell death to preserve a replicative niche and inhibition of T3SS effector antiphagocytic activities to allow invasion. These findings add to the growing body of evidence that ExoS-encoding (invasive) P. aeruginosa strains can be facultative intracellular pathogens, and that intracellularly secreted T3SS effectors contribute to pathogenesis. Author summary: While the ADPr domain of the T3SS effector ExoS plays multiple roles in the intracellular lifestyle of P. aeruginosa, ExoS can also be cytotoxic and/or antiphagocytic. Here, we show that when P. aeruginosa enters the cytosol of epithelial cells, cell death is triggered independently of T3SS effector toxins, but ExoS ADPr activity delays this to enable continued intracellular survival and replication. Using rhamnose induction to express the T3SS only after invasion restored this ExoS-dependent phenotype, showing that intracellularly secreted effectors can enable intracellular pathogenesis. ExoS ADPr activity also countered antiphagocytic activity of ExoS and ExoT RhoGAP domains. These results show two additional roles for ExoS ADPr activity in promoting internalization of P. aeruginosa and protecting the intracellular niche, continuing to challenge the notions that P. aeruginosa is exclusively an extracellular pathogen, that it needs to inject T3SS effectors across plasma membranes, and that ExoS is necessarily cytotoxic to host cells. [ABSTRACT FROM AUTHOR]

Background & Aims: Intense physical activity, despite its various benefits for general health, can cause possible damage to various tissues of the body due to increasing oxidative stress through increasing production of reactive species. Muscle bruising and pain is a common experience that occurs after performing unusual and intense activities, especially after resistance and extroverted activities. Delayed muscle spasm is associated with the release of creatine kinase, lactate dehydrogenase, and aspartate aminotransferase, and can be measured by the release of these enzymes into the blood. Numerous studies have examined the effect of resistance trainings on muscle injury indices that creatine kinase and lactate dehydrogenase, spartate aminotransferase, alanine aminotransferase and myoglobin indices increased significantly after exercise. In another study, they did not see any significant changes in CK and LDH muscle injury indices after 3 hours of cycling. Therefore, due to the injuries, researchers have drawn attention to the effects of resistance exercise on muscle injury indices. Although resistance training improves performance, it does not prevent the release of inflammatory and traumatic factors, so these factors can cause acute sports injuries, which will be especially important at a young age. Nowadays, special attention is paid to the use of various methods of resistance training, the most prominent of which is TRX or the same resistance training exercises suspended by body weight. Therefore, considering the different effects of sports activities, especially strength training on different parts of the body and the possibility of injury in these exercises, and considering the differences in the type of resistance training programs such as TRX and circular resistance, it is important to pay attention to the effects of this type of training and muscle injury indices. Also due to the contradictory results about the effect of exercise, especially the effect of resistance activity on muscle injury indices and also the lack of sufficient research on the long-term effect of TRX training on muscle injury indices and especially insufficient research on the comparison of resistance training and TRX, the researcher decided to compare 8 weeks of traditional resistance training and TRX on the indicators of muscle injury in inactive women. Methods: In this semi-experimental study, (28) healthy inactive girls with a mean age of 21.00 38 1.38 years were randomly divided into three groups: traditional resistance training (9), TRX training (9) and control (10). The experimental groups performed the training protocol three times a week for 8 weeks with an intensity of 65 to 80%. Blood samples were taken before training and 48 hours after the last training session and creatine kinase and lactate dehydrogenase levels were measured. Data were statistically analyzed using Shapiro-Wilk, dependent t-test and one-way analysis of variance. Results: The results showed that traditional resistance training and TRX both cause significant changes in LDH levels, while there was no significant difference in CPK variable from pre-test to post-test in all three groups. Also, in examining the differences between groups, no significant difference was observed between the three study groups at CPK levels. While there was a significant difference in the amount of lactate dehydrogenase between the three groups (p <0.05). According to the results of Table 3, there was a significant difference in the levels of lactate dehydrogenase between the resistance group and the TRX group (p = 0.0001), the control group with the TRX group (p = 0.0001) and the control group with the resistance group (p = 0.012) was observed. Conclusion: The presence of CK and LDH in the blood is an indirect sign of muscle damage as well as the diagnosis of medical conditions such as heart attack, muscular dystrophy and brain diseases. Cellular disorders, especially muscle cells, can cause CK and LDH to leak from cells into the blood serum. The findings of the present study showed that although there was a difference in the means of the three groups in both variables of creatine kinase and LDH, but this difference was significant only for LDH (P <0.05). The results of this study also showed that there is no significant difference in creatine kinase index between the two types of traditional resistance training and TRX after eight weeks. These factors affect the amount of response and the time period of secretion along with the injury. In general, the researchers state that intense resistance activities due to increased mechanical-metabolic pressure on the fibers lead to rupture of fibers, fluidization of z-plates, rupture of sarcolemma, displacement of intracellular organs, instability of plasma membranes and increasing secretion of intracellular proteins, after performing the resistant and intense activity. In fact, fatigue of muscle fibers following exhaustive activities can lead to increasing permeability of cell membranes to intracellular free calcium ions and dysfunction of sodium-potassium pumps, causing instability of cell membranes and activation of proteases and intracellular lipases. There is a close relationship between the release of phospholipases and creatine kinase due to the activity of intracellular proteolytic enzymes stimulated by calcium in the isolated muscle of mammals. The results of this study on LDH showed that the LDH of the experimental groups was significantly lower than the control group. Lactate dehydrogenase is one of the enzymes involved in the anaerobic pathway of ATP production. The secretion of lactate from the training muscle and the activity of the muscle pump indicate the role of continuous exercise training on the rate of cell damages. It has also been shown that trained people have less enzymatic release into the bloodstream than people who did not, which may be due to the adaptation of trained people to the physical activity and exercise; because the skeletal muscles of athletes and trained people have the highest amount of ATP, which is used during exercise and physical activity to maintain the integrity of the cell membrane, and as a result, reduces the leakage of enzymes into the blood. In any case, it seems that as a result of running consecutive weeks of regular exercise programs, intramuscular adaptation may be established, and the nature of resistance training programs causes adaptation to occur at all levels, including intramuscular and better blood supply, which reduces the activity level of CK and LDH enzymes as indicators of muscle and cell damage; therefore, it seems that the use of appropriate methods of training reduces the disruption of biochemical changes. Therefore, according to the findings of the present study, it can be stated that the implementation of TRX training program and traditional resistance both can significantly reduce the rate of LDH cell damage index and no change in CK, and there is no difference between this type of training on the indicators muscle damage in young women, so both types of exercise can have beneficial effects on muscle injury indices. [ABSTRACT FROM AUTHOR]

The potential use of Ligilactobacillus salivarius -derived bacteriocin for the control of L. monocytogenes was investigated. The purpose of the study was to explore the antibacterial action mode of crude bacteriocin C2-1 from Ligilactobacillus salivarius C2-1 against Listeria monocytogenes CICC 21633. The inhibition zone diameter of crude bacteriocin C2-1 was 27.82 ± 0.3 mm against L. monocytogenes CICC 21633, and the minimum inhibitory concentration (MIC) of bacteriocin C2-1was 13.98 μg/mL. Bacteriocin C2-1 significantly inhibited the normal growth of L. monocytogenes CICC21633, is sensitive to proteinase K, trypsin, and pepsin, and has good thermal stability and acid tolerance. The antibacterial mode of bacteriocin C2-1 against L. monocytogenes CICC 21633 was discussed based on changes in cell membrane permeability, integrity, and morphological structure of L. monocytogenes CICC 21633 by measuring the conductivity, UV-absorbing substance content and the observation via scanning electron microscopy, respectively. These results demonstrated that bacteriocin C2-1 affected the cell membrane permeability and integrity of L. monocytogenes CICC 21633, resulting in intracellular material leakage. Furthermore, bacteriocin-producing genes were identified in the genome sequence using antiSMASH and BAGEL4 assays. Bacteriocin C2-1 might be a good biological food preservative to prevent L. monocytogenes infestation. • Bacteriocin C2-1 has antimicrobial activity against Listeria monocytogenes CICC 21633. • Bacteriocin C2-1 can strongly inhibit the normal growth of Listeria monocytogenes CICC 21633. • High heat stability, pH tolerance, and protease sensitivity are all characteristics of bacteriocin C2-1. • The antibacterial action mode of bacteriocin C2-1 was studied against Listeria monocytogenes CICC 21633. • Whole-genome sequencing analysis revealed the presence of bacteriocin biosynthetic gene clusters in Lb. salivarius C2-1. [ABSTRACT FROM AUTHOR]

• The application of ultrasound and microbubbles (US + MBs) enhances the extravasation of macromolecular substance through blood–brain barrier via transcytosis mechanism. • The mechanical interaction between oscillating microbubbles and cell membranes results in direct membrane deformation and generates both mechanical and sonochemical effects. • The formation of pits on the cellular membrane surface is a critical step in the initiation of endocytosis or transcytosis processes. • US + MBs application induced membrane hyperpolarization and increase of cytosolic calcium concentration. • Mechanical interaction between oscillating microbubbles and cell membrane plays a necessary role in the dynamin-/caveolae-/clathrin- related transcytosis. The blood–brain barrier (BBB) maintains brain homeostasis, regulates influx and efflux transport, and provides protection to the brain tissue. Ultrasound (US) and microbubble (MB)-mediated blood–brain barrier opening is an effective and safe technique for drug delivery in-vitro and in-vivo. However, the exact mechanism underlying this technique is still not fully elucidated. The aim of the study is to explore the contribution of transcytosis in the BBB transient opening using an in-vitro model of BBB. Utilizing a diverse set of techniques, including Ca2+ imaging, electron microscopy, and electrophysiological recordings, our results showed that the combined use of US and MBs triggers membrane deformation within the endothelial cell membrane, a phenomenon primarily observed in the US + MBs group. This deformation facilitates the vesicles transportation of 500 kDa fluorescent Dextran via dynamin-/caveolae-/clathrin- mediated transcytosis pathway. Simultaneously, we observed increase of cytosolic Ca2+ concentration, which is related with increased permeability of the 500 kDa fluorescent Dextran in-vitro. This was found to be associated with the Ca2+-protein kinase C (PKC) signaling pathway. The insights provided by the acoustically-mediated interaction between the microbubbles and the cells delineate potential mechanisms for macromolecular substance permeability. [ABSTRACT FROM AUTHOR]

Blood-borne fatty acids (Fa) are important substrates for energy conversion in the mammalian heart. After release from plasma albumin, Fa traverse the endothelium and the interstitial compartment to cross the sarcolemma prior to oxidation in the cardiomyocytal mitochondria. The aims of the present study were to elucidate the site with lowest Fa permeability (i.e., highest Fa resistance) in the overall Fa trajectory from capillary to cardiomyocyte and the relative contribution of unbound Fa (detach pathway, characterized by the dissociation time constant τAlbFa) and albumin-bound Fa (contact pathway, characterized by the membrane reaction rate parameter dAlb) in delivering Fa to the cellular membranes. In this study, an extensive set of 34 multiple indicator dilution experiments with radiolabeled albumin and palmitate on isolated rabbit hearts was analysed by means of a previously developed mathematical model of Fa transfer dynamics. In these experiments, the ratio of the concentration of palmitate to albumin was set at 0.91. The analysis shows that total cardiac Fa permeability, Ptot, is indeed related to the albumin concentration in the extracellular compartment as predicted by the mathematical model. The analysis also reveals that the lowest permeability may reside in the boundary zones containing albumin in the microvascular and interstitial compartment. However, the permeability of the endothelial cytoplasm, Pec, may influence overall Fa permeability, Ptot, as well. The model analysis predicts that the most likely value of τAlbFa ranges from about 200 to 400 ms. In case τAlbFa is fast, i.e., about 200 ms, the extracellular contact pathway appears to be of minor importance in delivering Fa to the cell membrane. If Fa dissociation from albumin is slower, e.g. τAlbFa equals 400 ms, the contribution of the contact pathway may vary from minimal (dAlb≤5 nm) to substantial (dAlb about 100 nm). In the latter case, the permeability of the endothelial cytoplasm varies from infinite (no hindrance) to low (substantial hindrance) to keep the overall Fa flux at a fixed level. Definitive estimation of the impact of endothelial permeability on Ptot and the precise contribution of the contact pathway to overall transfer of Fa in boundary zones containing albumin requires adequate physicochemical experimentation to delineate the true value of, among others, τAlbFa, under physiologically relevant circumstances. Our analysis also implies that concentration differences of unbound Fa are the driving force of intra-cardiac Fa transfer; an active, energy requiring transport mechanism is not necessarily involved. Membrane-associated proteins may facilitate Fa transfer in the boundary zones containing albumin by modulating the membrane reaction rate parameter, dAlb, and, hence, the contribution of the contact pathway to intra-cardiac Fa transfer. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the dynamics of superoxide anion radical (O•2–) production rate and alterations in DNA content and permeability of cell membranes in etiolated wheat seedlings (Triticum aestivum L. cv. Harmony) as well as those grown under normal daylight regime. The results suggest that the development of etiolated wheat seedlings and those grown under normal daylight is accompanied by the periodic formation of O•2– which leads to alterations in DNA content as well as the permeability of cell membranes. The results also indicate that the first enhancement in the rate of O•2– generation was detected on the sixth and seventh days of development, after which the rate of O•2¯ production reduced in etiolated seedlings and those grown under normal daylight regime. The second maximum of the O•2¯ producing rate in developing and senescent organs occurred on the ninth day of plant development. The lowest values of all studied parameters, such as O•2– producing rate (37%), total genomic DNA concentration (58%) and electrolyte leakage (EL; 18%) were observed in etiolated wheat seedlings. Towards the end of the study period, DNA concentration and EL in organs of wheat seedlings declined, suggesting possible destruction of cellular organelles and the beginning of apoptotic processes. Overall, these results indicate that O•2– generation is decisive for normal morphogenesis, and it is an indispensable element of synchronous growth and development. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) not only is an oxidant but also is an important signaling molecule in vascular biology, mediating several physiological functions. Red blood cells (RBCs) have been proposed to be the primary sink of H2O2 in the vasculature because they are the main cellular component of blood with a robust antioxidant defense and a high membrane permeability. However, the exact permeability of human RBC to H2O2 is neither known nor is it known if the mechanism of permeation involves the lipid fraction or protein channels. To gain insight into the permeability process, we measured the partition constant of H2O2 between water and octanol or hexadecane using a novel double-partition method. Our results indicated that there is a large thermodynamic barrier to H2O2 permeation. The permeability coefficient of H2O2 through phospholipid membranes containing cholesterol with saturated or unsaturated acyl chains was determined to be 4 x 10-4 and 5 x 10-3 cm s-1, respectively, at 37 °C. The permeability coefficient of human RBC membranes to H2O2 at 37 °C, on the other hand, was 1.6 x 10-3 cm s-1. Different aquaporin-1 and aquaporin-3 inhibitors proved to have no effect on the permeation of H2O2. Moreover, human RBCs devoid of either aquaporin-1 or aquaporin-3 were equally permeable to H2O2 as normal human RBCs. Therefore, these results indicate that H2O2 does not diffuse into RBCs through aquaporins but rather through the lipid fraction or a still unidentified membrane protein. [ABSTRACT FROM AUTHOR]

Decabromodiphenyl ether (BDE-209), a major component of brominated flame retardants, has been detected in considerable amounts in the soil. Given that BDE-209 is toxic, ubiquitous, and persistent, it may cause toxic effects on vegetables planted in contaminated soil. In this study, Chinese cabbage seedlings cultivated in the soil contaminated by BDE-209 (5 - 20 mg kg-1) for 60 d were investigated to evaluate the phytotoxicity of BDE-209 in terms of growth, physiological responses, photosynthetic function, and antioxidant capacity. The results showed that BDE-209-induced phytotoxicity was reflected in the growth suppression, the decrease of chlorophyll content and soluble protein content, and especially in the reduced photosynthetic parameters (net photosynthetic rate and stomatal conductance). BDE-209 showed direct toxicities to plasma membranes causing their elevated permeability. In addition, BDE-209 induced the overproduction of reactive oxygen species (ROS), membrane lipid peroxidation and protein carbonylation, manifesting in the increased content of O2 •-, H2O2, malondialdehyde, and carbonyl. Chinese cabbage seedlings activated the antioxidant defence system (superoxide dismutase and peroxidase) to scavenge the ROS and counter-balance the oxidative stress caused by BDE-209, while the toxicity could not be effectively alleviated. Our study will provide valuable information for further understanding of the phytotoxicity of polybrominated diphenyl ethers. [ABSTRACT FROM AUTHOR]

Oxygen on its transport route from lung to tissue mitochondria has to cross several cell membranes. The permeability value of membranes for O2 (PO2), although of fundamental importance, is controversial. Previous studies by mostly indirect methods diverge between 0.6 and 125 cm/s. Here, we use a most direct approach by observing transmembrane O2 fluxes out of 100 nm liposomes at defined transmembrane O2 gradients in a stopped-flow system. Due to the small size of the liposomes intra- as well as extraliposomal diffusion processes do not affect the overall kinetics of the O2 release process. We find, for cholesterol-free liposomes, the unexpectedly low PO2 value of 0.03 cm/s at 35 °C. This PO2 would present a serious obstacle to O2 entering or leaving the erythrocyte. Cholesterol turns out to be a novel major modifier of PO2, able to increase PO2 by an order of magnitude. With a membrane cholesterol of 45 mol% as it occurs in erythrocytes, PO2 rises to 0.2 cm/s at 35 °C. This PO2 is just sufficient to ensure complete O2 loading during passage of erythrocytes through the lung's capillary bed under the conditions of rest as well as maximal exercise. [ABSTRACT FROM AUTHOR]

Cell membrane permeability is one of the main indicators of cytotoxicity and related to many critical biological pathways. Here, we determined the Cd2+-induced membrane permeability of human MCF-7 cells using ferrocene methanol molecular probes based on scanning electrochemical microscopy (SECM). The cell height and topography were examined with an impermeable Ru(NH3)6Cl3 probe. The membrane permeability exhibited no significant changes when the Cd2+ incubation time was less than 2 h and its concentration was less than 40 μM. The permeability increased when the Cd2+ concentration was greater than 60 μM, or when the incubation time was longer than 3 h. From the combined 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and cytoskeleton imaging experiments, it was found that the changes occurred because the cells exhibited a defensive mode and their membranes contracted when treated with a low concentration of Cd2+ for a short time. However, the cell membranes were irreversibly damaged when the cytoskeleton structures were destroyed, and the cell activities decreased at high concentrations over long periods. Interestingly, through the comparison with an x-scan study, it was found that DPV technology shows a higher performance in the detection of changes in the membrane permeability. Using a combination of cytoskeleton fluorescence imaging and cell-viability tests, the effect of the cadmium metal on the cell membrane permeability can be explored deeper and more comprehensively. This study provides a new idea for exploring the changes in the cell membrane permeability and may be helpful for rapid evaluation of cytotoxicity. [ABSTRACT FROM AUTHOR]

The composition and biophysical properties of cellular membranes must be tightly regulated to maintain the proper functions of myriad processes within cells. To better understand the importance of membrane homeostasis, we assembled a panel of five Caenorhabditis elegans strains that show a wide span of membrane composition and properties, ranging from excessively rich in saturated fatty acids (SFAs) and rigid to excessively rich in polyunsaturated fatty acids (PUFAs) and fluid. The genotypes of the five strain are, from most rigid to most fluid: paqr-1(tm3262); paqr-2(tm3410), paqr-2(tm3410), N2 (wild-type), mdt-15(et14); nhr-49(et8), and mdt-15(et14); nhr-49(et8); acs-13(et54). We confirmed the excess SFA/rigidity-to-excess PUFA/fluidity gradient using the methods of fluorescence recovery after photobleaching (FRAP) and lipidomics analysis. The five strains were then studied for a variety of cellular and physiological traits and found to exhibit defects in: permeability, lipid peroxidation, growth at different temperatures, tolerance to SFA-rich diets, lifespan, brood size, vitellogenin trafficking, oogenesis, and autophagy during starvation. The excessively rigid strains often exhibited defects in opposite directions compared to the excessively fluid strains. We conclude that deviation from wild-type membrane homeostasis is pleiotropically deleterious for numerous cellular/physiological traits. The strains introduced here should prove useful to further study the cellular and physiological consequences of impaired membrane homeostasis. [ABSTRACT FROM AUTHOR]

Genome-wide association studies revealed that loss-of-function mutations in protein tyrosine phosphatase non-receptor type 2 (PTPN2) increase the risk of developing chronic immune diseases, such as inflammatory bowel disease (IBD) and celiac disease. These conditions are associated with increased intestinal permeability as an early etiological event. The aim of this study was to examine the consequences of deficient activity of the PTPN2 gene product, T cell protein tyrosine phosphatase (TCPTP), on intestinal barrier function and tight junction organization in vivo and in vitro. Here, we demonstrate that TCPTP protected against intestinal barrier dysfunction induced by the inflammatory cytokine IFN-γ by 2 mechanisms: it maintained localization of zonula occludens 1 and occludin at apical tight junctions and restricted both expression and insertion of the cation pore-forming transmembrane protein, claudin-2, at tight junctions through upregulation of the inhibitory cysteine protease, matriptase. We also confirmed that the loss-of-function PTPN2 rs1893217 SNP was associated with increased intestinal claudin-2 expression in patients with IBD. Moreover, elevated claudin-2 levels and paracellular electrolyte flux in TCPTP-deficient intestinal epithelial cells were normalized by recombinant matriptase. Our findings uncover distinct and critical roles for epithelial TCPTP in preserving intestinal barrier integrity, thereby proposing a mechanism by which PTPN2 mutations contribute to IBD. [ABSTRACT FROM AUTHOR]

Photodynamic therapy has always been an antibacterial tool for solving multi-drug resistant bacteria problem, but the side effects and the low efficiency due to the high aggregation and low solubility of photosensitizers limit its application. Due to the anti-inflammatory effect of caffeic acid, two novel photosensitizers (CA-1-TBO, CA-TBO) were synthesized by conjugating caffeic acid with toluidine blue O (TBO). The structures have been characterized by 1HNMR and high-resolution mass spectrometry. The UV–vis absorption, fluorescence spectra and the octanol-water partition coefficient of two photosensitizers were measured to evaluate their photophysical properties and hydrophilic/hydrophobic properties. Compared with parent TBO, the two modified photosensitizers have shown a higher quantum yield and kinetics constants of singlet oxygen, which has been supported by the simulation results of density functional theory. As drug-resistant representatives of gram-positive and gram-negative bacteria, respectively, S. aureus and P. aeruginosa have been used for in vitro antibacterial experiments. The sterilization efficiencies of the two modified photosensitizers far exceed that of parent TBO. The results of the octanol-water partition coefficient and fluorescence quantification showed that modified photosensitizers CA-1-TBO and CA-TBO could be more accumulated than parent TBO. Based on scanning electron microscopy images, protein gel electrophoresis, and the conductivity of the bacterial solution, the possible mechanism of improved antibacterial photodynamic efficiencies could be induced by membrane permeability due to the caffeic acid effect. The findings demonstrate the significant potential of natural phenolic compounds in the development of photosensitizer molecules with characteristics such as more efficient, biocompatible and less side effects. • Novel photosensitizers from caffeic acid and toluidine blue O have been prepared. • CA-1-TBO and CA-TBO can penetrate bacterial membranes. • CA-1-TBO and CA-TBO could accumulate efficiently into bacterial cells. • CA-1-TBO and CA-TBO showed the enhanced aPDT efficiency. • CA-1-TBO and CA-TBO could target intracellular proteins. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel isomeric methotrexate-betulonic acid hybrids have been synthesized. • Experiments with artificial membranes confirmed high lipophilicity of hybrids. • The ability of the conjugates to penetrate Caco-2 cells has been evaluated. An efficient protocol for the synthesis of novel methotrexate-betulonic acid hybrids with a (tert -butoxycarbonylamino)-3,6-dioxa-8-octanamine (Boc -DOOA) linkage has been developed. Reaction of N-(2-(2-(2-aminoethoxy)ethoxy)ethyl)-betulonamide with methotrexate resulted in a mixture of isomeric conjugates which were separated by column chromatography. Their structures and composition have been fully established by 1H NMR, 13C spectra, FAB mass spectrometry and elemental analysis. The identity of conjugates was confirmed by LC-MS data. Membranotropic properties of the new hybrids were assessed on the basis of their interactions with artificial lipid membranes by differential scanning calorimetry (DSC) method. The ability of the conjugates to penetrate Caco-2 cells is inferior to methotrexate. Probably, this is due to the increasing lipophilicity, the affinity of these hybrid molecules for the lipid bilayer increases, which is confirmed by experiments with artificial membranes. [ABSTRACT FROM AUTHOR]

Phospholipase A1 (PlaA) plays a pivotal role in diverse applications within the food and biochemical medical industries. Herein, we investigate the impact of the accessory protein encoded by plaS from Serratia marcescens on PlaA activity in Escherichia coli. Notably, PlaS demonstrates the ability to enhance PlaA activity while concurrently exhibiting inhibitory effects on the growth of E. coli BL21 (DE3). Our study revolves around probing the inhibitory action of PlaS on E. coli BL21 (DE3). PlaS exhibits a propensity to heighten both the permeability of outer and inner cell membranes, leading to concomitant reductions in membrane fluidity and surface hydrophobicity. This phenomenon is validated through scanning electron microscopy (SEM) analysis, which highlights PlaS's capacity to compromise membrane integrity. Moreover, through a comprehensive comparative transcriptomic sequencing approach, we identify four down-regulated genes (galM , ybhC , ldtC , and kdpB) alongside two up-regulated genes (rbsB and degP). These genes are intricately associated with processes such as cell membrane synthesis and modification, energy metabolism, and transmembrane transport. Our investigation unveils the intricate gene-level mechanisms underpinning PlaS-mediated growth inhibition and membrane disruption. Consequently, our findings serve as a significant reference for the elucidation of membrane protein mechanisms, shedding light on potential avenues for future exploration. • The accessory protein PlaS located on cell membranes • PlaS damage the integrity of cell membrane and inhibit the growth of E. coli. • PlaS affect the permeability, fluidity and hydrophobicity of E. coli. • Comparative transcriptomic analysis the mechanism of PlaS [ABSTRACT FROM AUTHOR]

Values of cell membranes permeability coefficients for water and molecules of cryoprotective agents (CPAs) are the necessary characteristics for developing physical-mathematical models describing mass transfer processes through cell membranes in order to predict optimal cell cooling rates. We carried out a comparative analysis of the permeability coefficients of mouse oocyte membranes for molecules of water, ethylene glycol (EG), propane-1,2-diol (1,2-PD) and dimethyl sulfoxide (Me 2 SO), determined by applying the classical Kedem-Katchalsky model, which considers only the penetration of non-electrolyte molecules (water and CPA) through the membrane, and the model developed by us, which takes into account the transmembrane transfer of ions and the associated changes in the transmembrane electric potential. We shown that calculations based on the developed modified model provide lower values of the permeability coefficients of the oocyte membrane for water and CPA molecules. What is important that the obtained by our modified model permeability coefficients for water molecules do not depend on the type of cryoprotectant, while the application of the classical model both in our studies and works of other authors always gave different values of these coefficients in solutions with different cryoprotectants. Our modified model also makes it possible to determine the dynamics of the transmembrane electric potential of the cell under the conditions of transmembrane mass transfer and the duration of the membrane being influenced by the changes in electric potential, that is a parameter that can directly affect the viability of cells. • The physical-mathematical model for determining of cell's permeability coefficients considering transmembrane ion transfer. • Modified model makes it possible to determine the dynamics of the transmembrane potential during cryoprotectant penetration. • Maximum change in the transmembrane potential depend on the rate of the cryoprotectant penetration into the cell. • Our model provides values of permeability coefficients for water that do not depend on the type of cryoprotectant. [ABSTRACT FROM AUTHOR]