OBJECTIVE: To explore the regulation of mitochondria on platelet apoptosis and activation, and the relationship between platelet apoptosis and activation. METHODS: Platelets were isolated from peripheral venous blood of healthy volunteers. Cyclosporin A (CsA), which has a protective effect on the function of platelet mitochondria, BAPTA, which can chelate calcium ions across membranes in platelets, and NAC, an antioxidant that reduces the level of intracellular reactive oxygen species, were selected for coincubation with washed platelets, respectively. By flow cytometry, platelet aggregator was used to detect the changes of platelet mitochondrial function and platelet activation indexes after different interventions. RESULTS: H89, staurosporine, and A23187 led to platelet mitochondrial abnormalities, while CsA could effectively reverse the decline of platelet mitochondrial membrane potential caused by them. Antioxidant NAC could reverse platelet mitochondrial damage correspondingly, and completely reverse platelet shrinkage and phosphatidylserine eversion induced by H89. BAPTA, prostaglandin E1, acetylsalicylic acid and other inhibitors could not reverse the decline of platelet mitochondrial membrane potential. CONCLUSION Mitochondrial function plays an important role in platelet apoptosis and activation. Abnormal mitochondrial function causes the imbalance of reduction/oxidation state in platelets, which leads to platelet apoptosis. Platelet apoptosis and activation are independent signal processes.
Humans ; Blood Platelets/metabolism* ; Antioxidants/pharmacology* ; Mitochondria/physiology* ; Platelet Activation ; Apoptosis ; Membrane Potential, Mitochondrial ; Reactive Oxygen Species/pharmacology*

OBJECTIVE: To investigate whether hydrogen-rich water exerts a protective effect against cellular injury by affecting the level of autophagy after oxygen glucose deprivation/reoxygenation (OGD/R) in a mouse hippocampal neuronal cell line (HT22 cells). METHODS: HT22 cells in logarithmic growth phase were cultured in vitro. Cell viability was detected by cell counting kit-8 (CCK-8) assay to find the optimal concentration of Na₂S₂O₄. HT22 cells were divided into control group (NC group), OGD/R group (sugar-free medium+10 mmol/L Na₂S₂O₄ treated for 90 minutes and then changed to normal medium for 4 hours) and hydrogen-rich water treatment group (HW group, sugar-free medium+10 mmol/L Na₂S₂O₄ treated for 90 minutes and then changed to medium containing hydrogen-rich water for 4 hours). The morphology of HT22 cells was observed by inverted microscopy; cell activity was detected by CCK-8 method; cell ultrastructure was observed by transmission electron microscopy; the expression of microtubule-associated protein 1 light chain 3 (LC3) and Beclin-1 was detected by immunofluorescence; the protein expression of LC3II/I and Beclin-1, markers of cellular autophagy, was detected by Western blotting. RESULTS: Inverted microscopy showed that compared with the NC group, the OGD/R group had poor cell status, swollen cytosol, visible cell lysis fragments and significantly lower cell activity [(49.1±2.7)% vs. (100.0±9.7)%, P < 0.01]; compared with the OGD/R group, the HW group had improved cell status and remarkably higher cell activity [(63.3±1.8)% vs. (49.1±2.7)%, P < 0.01]. Transmission electron microscopy showed that the neuronal nuclear membrane of cells in the OGD/R group was lysed and a higher number of autophagic lysosomes were visible compared with the NC group; compared with the OGD/R group, the neuronal damage of cells in the HW group was reduced and the number of autophagic lysosomes was notably decreased. The results of immunofluorescence assay showed that the expressions of LC3 and Beclin-1 were outstandingly enhanced in the OGD/R group compared with the NC group, and the expressions of LC3 and Beclin-1 were markedly weakened in the HW group compared with the OGD/R group. Western blotting assay showed that the expressions were prominently higher in both LC3II/I and Beclin-1 in the OGD/R group compared with the NC group (LC3II/I: 1.44±0.05 vs. 0.37±0.03, Beclin-1/β-actin: 1.00±0.02 vs. 0.64±0.01, both P < 0.01); compared with the OGD/R group, the protein expression of both LC3II/I and Beclin-1 in the HW group cells were notably lower (LC3II/I: 0.54±0.02 vs. 1.44±0.05, Beclin-1/β-actin: 0.83±0.07 vs. 1.00±0.02, both P < 0.01). CONCLUSIONS Hydrogen-rich water has a significant protective effect on OGD/R-causing HT22 cell injury, and the mechanism may be related to the inhibition of autophagy.
Mice ; Animals ; Oxygen/metabolism* ; Beclin-1/pharmacology* ; Glucose/metabolism* ; Actins ; Sincalide ; Autophagy/physiology* ; Hydrogen/pharmacology* ; Reperfusion Injury ; Apoptosis

The study aims to explore the effect of mesenchymal stem cells-derived exosomes (MSCs-Exo) on staurosporine (STS)-induced chondrocyte apoptosis before and after exposure to pulsed electromagnetic field (PEMF) at different frequencies. The AMSCs were extracted from the epididymal fat of healthy rats before and after exposure to the PEMF at 1 mT amplitude and a frequency of 15, 45, and 75 Hz, respectively, in an incubator. MSCs-Exo was extracted and identified. Exosomes were labeled with DiO fluorescent dye, and then co-cultured with STS-induced chondrocytes for 24 h. Cellular uptake of MSC-Exo, apoptosis, and the protein and mRNA expression of aggrecan, caspase-3 and collagenⅡA in chondrocytes were observed. The study demonstrated that the exposure of 75 Hz PEMF was superior to 15 and 45 Hz PEMF in enhancing the effect of exosomes in alleviating chondrocyte apoptosis and promoting cell matrix synthesis. This study lays a foundation for the regulatory mechanism of PEMF stimulation on MSCs-Exo in inhibiting chondrocyte apoptosis, and opens up a new direction for the prevention and treatment of osteoarthritis.
Animals ; Rats ; Apoptosis ; Chondrocytes ; Electromagnetic Fields ; Exosomes/physiology* ; Mesenchymal Stem Cells/metabolism*

BACKGROUND: Perturbations in bone marrow mesenchymal stem cell (BMSC) differentiation play an important role in steroid-induced osteonecrosis of the femoral head (SONFH). At present, studies on SONFH concentrate upon the balance within BMSC osteogenic and adipogenic differentiation. However, BMSC apoptosis as well as proliferation are important prerequisites in their differentiation. The hedgehog (HH) signaling pathway regulates bone cell apoptosis. Baicalin (BA), a well-known compound in traditional Chinese medicine, can affect the proliferation and apoptosis of numerous cell types via HH signaling. However, the potential role and mechanisms of BA on BMSCs are unclear. Thus, we aimed to explore the role of BA in dexamethasone (Dex)-induced BMSC apoptosis in this study. METHODS: Primary BMSCs were treated with 10 -6 mol/L Dex alone or with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA for 24 hours followed by co-treatment with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA and 10 -6 mol/L Dex. Cell viability was assayed through the Cell Counting Kit-8 (CCK-8). Cell apoptosis was evaluated using Annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining followed by flow cytometry. The imaging and counting, respectively, of Hochest 33342/PI-stained cells were used to assess the morphological characteristics and proportion of apoptotic cells. To quantify the apoptosis-related proteins (e.g., apoptosis regulator BAX [Bax], B-cell lymphoma 2 [Bcl-2], caspase-3, and cleaved caspase-3) and HH signaling pathway proteins, western blotting was used. A HH-signaling pathway inhibitor was used to demonstrate that BA exerts its anti-apoptotic effects via the HH signaling pathway. RESULTS: The results of CCK-8, Hoechst 33342/PI-staining, and flow cytometry showed that BA did not significantly promote cell proliferation (CCK-8: 0 μmol/L, 100%; 2.5 μmol/L, 98.58%; 5.0 μmol/L, 95.18%; 10.0 μmol/L, 98.11%; 50.0 μmol/L, 99.38%, F   =  2.33, P   >  0.05), but it did attenuate the effect of Dex on apoptosis (Hoechst 33342/PI-staining: Dex+ 50.0 μmol/L BA, 12.27% vs. Dex, 39.27%, t  = 20.62; flow cytometry: Dex + 50.0 μmol/L BA, 12.68% vs. Dex, 37.43%, t  = 11.56; Both P  < 0.05). The results of western blotting analysis showed that BA reversed Dex-induced apoptosis by activating the HH signaling pathway, which down-regulated the expression of Bax, cleaved-caspase 3, and suppressor of fused (SUFU) while up-regulating Bcl-2, sonic hedgehog (SHH), and zinc finger protein GLI-1 (GLI-1) expression (Bax/Bcl-2: Dex+ 50.0 μmol/L BA, 1.09 vs. Dex, 2.76, t  = 35.12; cleaved caspase-3/caspase-3: Dex + 50.0 μmol/L BA, 0.38 vs . Dex, 0.73, t  = 10.62; SHH: Dex + 50.0 μmol/L BA, 0.50 vs . Dex, 0.12, t  = 34.01; SUFU: Dex+ 50.0 μmol/L BA, 0.75 vs . Dex, 1.19, t  = 10.78; GLI-1: Dex+ 50.0 μmol/L BA, 0.40 vs . Dex, 0.11, t  = 30.68. All P  < 0.05). CONCLUSIONS BA antagonizes Dex-induced apoptosis of human BMSCs by activating the HH signaling pathway. It is a potential candidate for preventing SONFH.
Humans ; Hedgehog Proteins/metabolism* ; bcl-2-Associated X Protein ; Caspase 3/metabolism* ; Signal Transduction/physiology* ; Apoptosis ; Apoptosis Regulatory Proteins/pharmacology* ; Dexamethasone/pharmacology* ; Mesenchymal Stem Cells/metabolism* ; Bone Marrow Cells

Chronological aging is the leading risk factor for human diseases, while aging at the cellular level, namely cellular senescence, is the fundamental driving force of organismal aging. The impact of cellular senescence on various life processes, including normal physiology, organismal aging and the progress of various age-related pathologies, has been largely ignored for a long time. However, with recent advancement in relevant fields, cellular senescence has become the core of aging biology and geriatric medicine. Although senescent cells play important roles in physiological processes including tissue repair, wound healing, and embryonic development, they can also contribute to tissue dysfunction, organ degeneration and various pathological conditions during adulthood. Senescent cells exert paracrine effects on neighboring cells in tissue microenvironments by developing a senescence-associated secretory phenotype, thus maintaining long-term and active intercellular communications that ultimately results in multiple pathophysiological effects. This is regarded as one of the most important discoveries in life science of this century. Notably, selective elimination of senescent cells through inducing their apoptosis or specifically inhibiting the senescence-associated secretory phenotype has shown remarkable potential in preclinical and clinical interventions of aging and age-related diseases. This reinforces the belief that senescent cells are the key drug target to alleviate various aging syndromes. However, senescent cells exhibit heterogeneity in terms of form, function and tissue distribution, and even differ among species, which presents a challenge for the translation of significant research achievements to clinical practice in future. This article reviews and discusses the characteristics of senescent cells, current targeting strategies and future trends, providing useful and valuable references for the rapidly blooming aging biology and geriatric medicine.
Humans ; Adult ; Aged ; Cellular Senescence/genetics* ; Aging ; Apoptosis ; Cell Communication ; Wound Healing/physiology*

Necroptosis is one of the regulated cell death, which involves receptor interacting protein kinase (RIPK) 1/RIPK3/mixed lineage kinase domain like protein (MLKL) signaling pathway. Among them, MLKL is the final execution of necroptosis. The formation of RIPK1/RIPK3/MLKL necrosome induces the phosphorylated MLKL, and the activated MLKL penetrates into the membrane bilayer to form membrane pores, which damages the integrity of the membrane and leads to cell death. In addition to participating in necroptosis, MLKL is also closely related to other cell death, such as NETosis, pyroptosis, and autophagy. Therefore, MLKL is involved in the pathological processes of various diseases related to abnormal cell death pathways (such as cardiovascular diseases, neurodegenerative diseases and cancer), and may be a therapeutic target of multiple diseases. Understanding the role of MLKL in different cell death can lay a foundation for seeking various MLKL-related disease targets, and also guide the development and application of MLKL inhibitors.
Protein Kinases/metabolism* ; Necroptosis/physiology* ; Receptor-Interacting Protein Serine-Threonine Kinases ; Signal Transduction ; Pyroptosis ; Apoptosis

Sympathetic cues via the adrenergic signaling critically regulate bone homeostasis and contribute to neurostress-induced bone loss, but the mechanisms and therapeutics remain incompletely elucidated. Here, we reveal an osteoclastogenesis-centered functionally important osteopenic pathogenesis under sympatho-adrenergic activation with characterized microRNA response and efficient therapeutics. We discovered that osteoclastic miR-21 was tightly regulated by sympatho-adrenergic cues downstream the β2-adrenergic receptor (β₂AR) signaling, critically modulated osteoclastogenesis in vivo by inhibiting programmed cell death 4 (Pdcd4), and mediated detrimental effects of both isoproterenol (ISO) and chronic variable stress (CVS) on bone. Intriguingly, without affecting osteoblastic bone formation, bone protection against ISO and CVS was sufficiently achieved by a (D-Asp₈)-lipid nanoparticle-mediated targeted inhibition of osteoclastic miR-21 or by clinically relevant drugs to suppress osteoclastogenesis. Collectively, these results unravel a previously underdetermined molecular and functional paradigm that osteoclastogenesis crucially contributes to sympatho-adrenergic regulation of bone and establish multiple targeted therapeutic strategies to counteract osteopenias under stresses.
Adrenergic Agents/pharmacology* ; Apoptosis Regulatory Proteins/pharmacology* ; Bone Diseases, Metabolic/metabolism* ; Humans ; Liposomes ; MicroRNAs/genetics* ; Nanoparticles ; Osteoclasts ; Osteogenesis/physiology* ; RNA-Binding Proteins/pharmacology*

OBJECTIVE: To explore the molecular mechanism by which microRNA let-7g-3p regulates biological behaviors of bladder cancer cells. METHODS: The expression levels of let-7g-3p in bladder cancer and adjacent tissues, normal bladder epithelial cells (HUC cells) and bladder cancer cells (T24, 5637 and EJ cells) were detected using qRT- PCR. T24 cells were transfected with let-7g-3p mimic or inhibitor, and the changes in cell proliferation, migration, invasion, and apoptosis were examined. Transcriptome sequencing was carried out in cells overexpressing let-7g-3p, and the results of bioinformatics analysis, double luciferase reporter gene assay, qRT-PCR and Western blotting confirmed that HMGB2 gene was the target gene of let-7g-3p. The expression of HMGB2 was examined in HUC, T24, 5637 and EJ cells, and in cells with HMGB2 knockdown, the effect of let-7g-3p knockdown on the biological behaviors were observed. RESULTS: qRT-qPCR confirmed that let-7g-3p expression was significantly lower in bladder cancer tissues and cells (P < 0.01). Overexpression of let-7g-3p inhibited cell proliferation, migration and invasion, and promoted cell apoptosis, while let-7g-3p knock-down produced the opposite effects. Bioinformatics and transcriptome sequencing results showed that HMGB2 was the key molecule that mediate the effect of let-7g-3p on bladder cancer cells. Luciferase reporter gene assay, qRT-PCR and Western blotting all confirmed that HMGB2 was negatively regulated by let-7g-3p (P < 0.01). Knocking down HMGB2 could partially reverse the effect of let-7g-3p knockdown on the biological behaviors of the bladder cancer cells. CONCLUSION The microRNA let-7g-3p can inhibit the biological behavior of bladder cancer cells by negatively regulating HMGB2 gene.
Apoptosis ; Cell Line, Tumor ; Cell Movement/physiology* ; Cell Proliferation ; Epithelial Cells/metabolism* ; Gene Expression Regulation, Neoplastic ; HMGB2 Protein/metabolism* ; Humans ; MicroRNAs/metabolism* ; Urinary Bladder ; Urinary Bladder Neoplasms/genetics*

OBJECTIVE: To screen for aberrantly expressed genes in osteosarcoma cells and investigate the role of RHPN2 in regulating the proliferation, apoptosis, migration and tumorigenic abilities of osteosarcoma cells. METHODS: We used GEO2R to analyze the differential gene expression profile between osteosarcoma cells and normal cells in the GSE70414 dataset. RTqPCR and Western blotting were performed to detect RHPN2 expression in osteosarcoma cell lines MG-63, 143B and SAOS2. Two RHPN2-shRNA and a control NC-shRNA were designed to silence the expression of RHPN2 in 143B cells, and CCK8 assay, colony-forming assay, annexin V-FITC/PI staining and scratch assays were carried out to examine the changes in proliferation, apoptosis and migration of the cells. We also established nude mouse models bearing osteosarcoma xenografts derived 143B cells and RHPN2-shRNA-transfected 143B cells, and assessed the effect of RHPN2 silencing on osteosarcoma cell tumorigenesis using HE staining. Kaplan-Meier survival curves were used to analyze the correlation between RHPN2 expression and survival outcomes of patients with osteosarcoma. RESULTS: RHPN2 expression was significantly upregulated in osteosarcoma cell lines MG-63, 143B and SAOS2 (P < 0.01). Silencing of RHPN2 significantly inhibited the proliferation and migration of 143B cells in vitro, promoted cell apoptosis (P < 0.01), and suppressed tumorigenic capacity of the cells in nude mice. A high expression of RHPN2 was significantly correlated with a poor prognosis of patients with osteosarcoma (P < 0.05). CONCLUSION RHPN2 is highly expressed in osteosarcoma cells to promote cell proliferation and migration and inhibits cell apoptosis. A high expression of RHPN2 is associated with a poorer prognosis of the patients with osteosarcoma.
Adaptor Proteins, Signal Transducing/metabolism* ; Animals ; Apoptosis ; Bone Neoplasms/metabolism* ; Carcinogenesis ; Cell Line, Tumor ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Humans ; Immediate-Early Proteins ; Mice ; Mice, Nude ; Osteosarcoma/metabolism* ; RNA, Small Interfering/genetics*

Cancer is the leading cause of death worldwide. Drugs play a pivotal role in cancer treatment, but the complex biological processes of cancer cells seriously limit the efficacy of various anticancer drugs. Autophagy, a self-degradative system that maintains cellular homeostasis, universally operates under normal and stress conditions in cancer cells. The roles of autophagy in cancer treatment are still controversial because both stimulation and inhibition of autophagy have been reported to enhance the effects of anticancer drugs. Thus, the important question arises as to whether we should try to strengthen or suppress autophagy during cancer therapy. Currently, autophagy can be divided into four main forms according to its different functions during cancer treatment: cytoprotective (cell survival), cytotoxic (cell death), cytostatic (growth arrest), and nonprotective (no contribution to cell death or survival). In addition, various cell death modes, such as apoptosis, necrosis, ferroptosis, senescence, and mitotic catastrophe, all contribute to the anticancer effects of drugs. The interaction between autophagy and these cell death modes is complex and can lead to anticancer drugs having different or even completely opposite effects on treatment. Therefore, it is important to understand the underlying contexts in which autophagy inhibition or activation will be beneficial or detrimental. That is, appropriate therapeutic strategies should be adopted in light of the different functions of autophagy. This review provides an overview of recent insights into the evolving relationship between autophagy and cancer treatment.
Antineoplastic Agents/therapeutic use* ; Apoptosis ; Autophagy/physiology* ; Humans ; Necrosis/drug therapy* ; Neoplasms/therapy*