The timely and efficient repair of the plasma membrane in skeletal muscle cells following injury is critical for maintaining cellular function and tissue integrity. Extracellular vesicles (EVs) play a pivotal role in this process through multi-level mechanisms. This review systematically summarizes the generation, secretion, and multifunctional roles of EVs in the repair of skeletal muscle plasma membrane damage: (1) removing damaged membrane fragments and cellular debris via endocytosis and exocytosis to maintain plasma membrane stability; (2) fusing with the injured plasma membrane to supply essential components for membrane repair and restore membrane integrity; and (3) serving as a vital mediator of intercellular communication, transmitting repair signals, promoting intercellular interactions, and orchestrating multi-level responses to facilitate tissue regeneration and functional recovery. Additionally, this article explores the potential applications of EVs in the treatment of exercise-induced injuries and muscular diseases, aiming to provide theoretical insights and novel strategies for future research and EV-based therapeutic approaches.
Extracellular Vesicles/physiology* ; Humans ; Muscle, Skeletal/physiology* ; Cell Membrane/physiology* ; Animals ; Regeneration/physiology* ; Exocytosis/physiology* ; Endocytosis/physiology* ; Cell Communication/physiology*

Objectives miR-207 has been identified as being expressed in natural killer (NK) cell exosomes that play a role in disease progression; however, to date, there are no studies specifically linking miR-207 to tuberculosis (TB). Methods Bioinformatics methods employed for prediction, followed by a dual luciferase reporter assay to determine whether lysosome-associated membrane protein 2 (LAMP2) is targeted by miR-207. The experiments were divided into four groups using the liposome transfection method (OP-LAMP2 group: co-transfected with miR-207 mimics and LAMP2 overexpression plasmid; EP group: co-transfected with mimics NC and null-loaded plasmid; siLAMP2 group: transfected with siLAMP2; and siLAMP2-NC group: transfected with siLAMP2-NC). TB infection was modeled using H37Ra-infected Ana-1 cells. The impact of LAMP2 on intracellular mycobacterial load and clearance of extracellular residual mycobacteria were assessed by tuberculosis colony-forming unit counting. Flow cytometry was used to assess the total apoptosis rate. Real-time fluorescent quantitative PCR was conducted to determine the relative expression of LAMP2, apoptosis genes, pyroptosis genes, and autophagy genes. Western blot analysis was performed to measure the relative expression of LAMP2 proteins, apoptosis proteins, pyroptosis proteins, and autophagy proteins. Results Dual luciferase reporter assay test showed that there was a targeting relationship between LAMP2 and miR-207. The transfection model was successfully constructed under real-time fluorescent quantitative PCR and Western blot statistical analysis, and microscopic observation. The infection model was successfully established under microscopic observation. Colony forming unit counting revealed that the number of colonies in the OP-LAMP2 group was lower than that in the EP group, while the number of colonies in the siLAMP2 group was higher than that in the siLAMP2-NC group. Flow cytometry assay revealed that the total apoptosis in OP-LAMP2 group was lower than that in EP group, and the total apoptosis in siLAMP2 group was higher than that in siLAMP2-NC group. Real-time fluorescence quantitative PCR and Western blot analysis revealed that the relative expression of apoptosis and pyroptosis-related proteins and genes in the control group was lower in the OP-LAMP2 group compared to the EP group, and higher in the siLAMP2 group compared to the siLAMP2-NC group. Real-time fluorescence quantitative PCR detected that the relative expression of autophagy positively regulated genes Microtubule-associated protein 1 light chain 3(LC3)and Beclin1 in the OP-LAMP2 group was higher in the OP-LAMP2 group compared to the EP group, and lower in the siLAMP2 group compared to the siLAMP2-NC group, while the relative expression of negatively regulated autophagy genes followed the opposite trend to that of autophagy positively regulated genes. The relative expression of autophagy-related proteins was consistent with the trend of autophagy genes. Conclusions miR-207 enhances macrophage apoptosis, cellular pyroptosis and inhibits autophagy, promoting survival of Mycobacterium tuberculosis by targeting the autophagy-related protein LAMP2, thus offering a novel therapeutic direction for tuberculosis.
Lysosomal-Associated Membrane Protein 2/metabolism* ; MicroRNAs/metabolism* ; Mycobacterium tuberculosis/physiology* ; Autophagy/genetics* ; Humans ; Macrophages/metabolism* ; Apoptosis/genetics* ; Tuberculosis/metabolism* ; Cell Line ; Pyroptosis/genetics*

OBJECTIVES: The neurotoxicity of carbon monoxide (CO) to the central nervous system is a key pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Our previous study found that retinoic acid (RA) can suppress the neurotoxic effects of CO. This study further explores, in vivo and in vitro, the molecular mechanisms by which RA alleviates CO-induced central nervous system damage. METHODS: A cytotoxic model was established using the mouse hippocampal neuronal cell line HT22 and primary oligodendrocytes exposed to CO, and a DEACMP animal model was established in adult Kunming mice. Cell viability and apoptosis of hippocampal neurons and oligodendrocytes were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin V/propidium iodide (PI) double staining. The transcriptional and protein expression of each gene was detected using real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting. Long noncoding RNA (lncRNA) SNHG15 and LINGO-1 were knocked down or overexpressed to observe changes in neurons and oligodendrocytes. In DEACMP mice, SNHG15 or LINGO-1 were knocked down to assess changes in central nervous tissue and downstream protein expression. RESULTS: RA at 10 and 20 μmol/L significantly reversed CO-induced apoptosis of hippocampal neurons and oligodendrocytes, downregulation of SNHG15 and LINGO-1, and upregulation of brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) (all P<0.05). Overexpression of SNHG15 or LINGO-1 weakened the protective effect of RA against CO-induced cytotoxicity (all P<0.05). Knockdown of SNHG15 or LINGO-1 alleviated CO-induced apoptosis of hippocampal neurons and oligodendrocytes and upregulated BDNF and TrkB expression levels (all P<0.05). Experiments in DEACMP model mice showed that knockdown of SNHG15 or LINGO-1 mitigated central nervous system injury in DEACMP (all P<0.05). CONCLUSIONS RA alleviates CO-induced apoptosis of hippocampal neurons and oligodendrocytes, thereby reducing central nervous system injury and exerting neuroprotective effects. LncRNA SNHG15 and LINGO-1 are key molecules mediating RA-induced inhibition of neuronal apoptosis and are associated with the BDNF/TrkB pathway. These findings provide a theoretical framework for optimizing the clinical treatment of DEACMP and lay an experimental foundation for elucidating its molecular mechanisms.
Animals ; RNA, Long Noncoding/physiology* ; Brain-Derived Neurotrophic Factor/genetics* ; Carbon Monoxide Poisoning/complications* ; Mice ; Tretinoin/pharmacology* ; Nerve Tissue Proteins/metabolism* ; Membrane Proteins/metabolism* ; Apoptosis/drug effects* ; Hippocampus/cytology* ; Receptor, trkB/metabolism* ; Neurons/drug effects* ; Male ; Brain Diseases/etiology* ; Oligodendroglia/drug effects* ; Signal Transduction ; Cell Line

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.
Adoptive Transfer ; Alveolar Epithelial Cells ; pathology ; Animals ; Apoptosis ; Betacoronavirus ; Body Fluids ; metabolism ; CD4-Positive T-Lymphocytes ; immunology ; Clinical Trials as Topic ; Coinfection ; prevention & control ; therapy ; Coronavirus Infections ; complications ; immunology ; Disease Models, Animal ; Endothelial Cells ; pathology ; Extracorporeal Membrane Oxygenation ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; therapeutic use ; Humans ; Immunity, Innate ; Inflammation Mediators ; metabolism ; Lung ; pathology ; physiopathology ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stem Cells ; physiology ; Multiple Organ Failure ; etiology ; prevention & control ; Pandemics ; Pneumonia, Viral ; complications ; immunology ; Respiratory Distress Syndrome, Adult ; immunology ; pathology ; therapy ; Translational Medical Research

Ion channels are a widespread class of membrane proteins that help establish and control cell membrane potential by allowing the passive diffusion of inorganic ions with high specificity through cell membrane. They are widely distributed in various cells and tissues, and their normal structure and function are of fundamental importance for all living organisms. The rapid advances in molecular cloning, protein structure analysis, patch clamp recordings and other technologies have greatly promoted the research on the biophysical and molecular properties of ion channels, and made significant progress in the study of the relationship between ion channels and pathophysiology as well. The immune system is made up of immune cells and organs that work together to protect the body and respond to infection and disease. Remarkably, recent basic and clinical research has revealed that ion channels are frequently and abundantly expressed in immune cells and have crucial roles in immune cell development and immune response. This review summarized recent progress in the roles of ion channels in immune cells, including the expression and regulation of ion channels in immune cells, the effects of ion flux mediated by ion channels on lymphocyte development, and functional roles of ion channels in both innate and adaptive immune responses. We also discussed some unresolved and insufficiently addressed issues in the current research, so as to provide an informative reference for better understanding the functional roles of ion channels in the immune system and further elucidation of their function from a physiological and pathological point of view.
Cell Membrane ; Immunity ; physiology ; Ion Channels ; immunology ; Membrane Proteins ; Research ; trends

OBJECTIVE: To investigate the effects of salvianolic acid A (SAA) on cardiomyocyte apoptosis and mitochondrial dysfunction in response to hypoxia/reoxygenation (H/R) injury and to determine whether the Akt signaling pathway might play a role. METHODS: An in vitro model of H/R injury was used to study outcomes on primary cultured neonatal rat cardiomyocytes. The cardiomyocytes were treated with 12.5, 25, 50 μg/mL SAA at the beginning of hypoxia and reoxygenation, respectively. Adenosine triphospate (ATP) and reactive oxygen species (ROS) levels were assayed. Cell apoptosis was evaluated by flow cytometry and the expression of cleaved-caspase 3, Bax and Bcl-2 were detected by Western blotting. The effects of SAA on mitochondrial dysfunction were examined by determining the mitochondrial membrane potential (△Ψm) and mitochondrial permeability transition pore (mPTP), followed by the phosphorylation of Akt (p-Akt) and GSK-3β (p-GSK-3β), which were measured by Western blotting. RESULTS: SAA significantly preserved ATP levels and reduced ROS production. Importantly, SAA markedly reduced the number of apoptotic cells and decreased cleaved-caspase 3 expression levels, while also reducing the ratio of Bax/Bcl-2. Furthermore, SAA prevented the loss of △Ψm and inhibited the activation of mPTP. Western blotting experiments further revealed that SAA significantly increased the expression of p-Akt and p-GSK-3β, and the increase in p-GSK-3β expression was attenuated after inhibition of the Akt signaling pathway with LY294002. CONCLUSION SAA has a protective effect on cardiomyocyte H/R injury; the underlying mechanism may be related to the preservation of mitochondrial function and the activation of the Akt/GSK-3β signaling pathway.
Adenosine Triphosphate ; analysis ; Animals ; Animals, Newborn ; Caffeic Acids ; pharmacology ; Cell Hypoxia ; Cells, Cultured ; Glycogen Synthase Kinase 3 beta ; physiology ; Lactates ; pharmacology ; Mitochondria, Heart ; drug effects ; physiology ; Mitochondrial Membrane Transport Proteins ; drug effects ; Myocytes, Cardiac ; drug effects ; Proto-Oncogene Proteins c-akt ; physiology ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; physiology

Proteins are the physical basis of life and perform all kinds of life activities. Proteins have different orientations and function in different tissues. The same protein, located in different subcellular regions, can perform different and even opposite functions. Both functional and structural proteins are capable of undergoing re-localization which can directly or indirectly participate in signal transduction. Due to abnormal transduction of signals during carcinogenesis, the proteins originally expressed in the cytoplasm are translocated into the nucleus and lead to functional changes in the tumor tissue. The changes of protein localization are affected by many factors, including the interaction between proteins, expression level of proteins and the cleaved intracellular domain of transmembrane protein.
Carcinogenesis ; pathology ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Cytoplasm ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; Membrane Proteins ; metabolism ; Protein Domains ; Protein Transport ; physiology ; Signal Transduction

Neuroligins (NLs) are postsynaptic cell-adhesion proteins that play important roles in synapse formation and the excitatory-inhibitory balance. They have been associated with autism in both human genetic and animal model studies, and affect synaptic connections and synaptic plasticity in several brain regions. Yet current research mainly focuses on pyramidal neurons, while the function of NLs in interneurons remains to be understood. To explore the functional difference among NLs in the subtype-specific synapse formation of both pyramidal neurons and interneurons, we performed viral-mediated shRNA knockdown of NLs in cultured rat cortical neurons and examined the synapses in the two major types of neurons. Our results showed that in both types of neurons, NL1 and NL3 were involved in excitatory synapse formation, and NL2 in GABAergic synapse formation. Interestingly, NL1 affected GABAergic synapse formation more specifically than NL3, and NL2 affected excitatory synapse density preferentially in pyramidal neurons. In summary, our results demonstrated that different NLs play distinct roles in regulating the development and balance of excitatory and inhibitory synapses in pyramidal neurons and interneurons.
Animals ; Cell Adhesion Molecules, Neuronal ; physiology ; Cells, Cultured ; Cerebral Cortex ; embryology ; physiology ; GABAergic Neurons ; physiology ; Interneurons ; physiology ; Membrane Proteins ; physiology ; Nerve Tissue Proteins ; physiology ; Protein Isoforms ; physiology ; Pyramidal Cells ; physiology ; Rats, Sprague-Dawley ; Synapses ; physiology

Drug metabolism is significantly affected under hypoxia environment with changes of pharmacokinetics, expression and function of drug-metabolizing enzymes and transporters. Studies have shown that hypoxia increases the release of a series of inflammatory cytokines which can modulate drug metabolism. Besides, both hypoxia inducible factor 1α (HIF-1α) and microRNA-mediated pathways play a role in regulating drug metabolism. This article reviewed the impact and single-factor modulating mechanisms of drug metabolism under hypoxia, and put forward the speculation and prospects of multi-factor modulating mechanisms.
Cell Hypoxia ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; Membrane Transport Proteins ; physiology ; MicroRNAs ; physiology ; Pharmaceutical Preparations ; metabolism

Cell-to-cell connections provide conduits for signal exchanges, and play important functional roles in physiological and pathological processes of multicellular organisms. Membrane nanotubes are common long-distance connections between cells, not only transfer molecule signals and mitochondria, but also cooperate with gap junction and other cell-to-cell communications to transfer signals. During the last decade, there are many studies about membrane nanotubes, which focus on the similarities and differences between membrane nanotubes and other cell-to-cell communications, as well as their biological functions. In the present review, we summarized the latest findings about the structural diversity, the similarities and differences in signal transmission with other types of cell-to-cell communications, and physiological and pathological roles of membrane nanotubes.
Cell Communication ; Cell Membrane ; physiology ; Gap Junctions ; physiology ; Humans ; Mitochondria ; physiology ; Nanotubes