cytochrome-c-t and Osteoarthritis

Topics: Animals; Antagomirs; Cartilage; Caspase 3; Cytochromes c; Female; Interleukin-6; MAP Kinase Kinase 4; MAP Kinase Signaling System; MicroRNAs; Mitogen-Activated Protein Kinases; Osteoarthritis; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Rabbits; Random Allocation; Regeneration; Tumor Necrosis Factor-alpha

Topics: Adenosine Triphosphate; Animals; Anti-Inflammatory Agents; Bone and Bones; C-Reactive Protein; COVID-19 Drug Treatment; Cytochromes c; Cytokines; Disease Models, Animal; Glutathione; Iodoacetic Acid; Lipid Peroxidation; Male; Matrix Metalloproteinases; Membrane Potential, Mitochondrial; Mitochondria; Osteoarthritis; Rats; Reactive Oxygen Species; SARS-CoV-2; Succinate Dehydrogenase

We have previously reported an application of lower range of molecular weight of xanthan gum (LRWXG) for inhibiting cartilage matrix destruction and preventing mitochondrial damage in rabbit osteoarthritis (OA) model. However, whether LRWXG exerts its anti-OA activity through intrinsic bax-mitochondria cytochrome c-caspase signaling pathway in OA still requires further study. To address this problem, the OA model was induced by anterior cruciate ligament transection (ACLT) in rabbit and then treated with LRWXG. The results showed that LRWXG could inhibit the loss of collagen in cartilage matrix, protect trabecular bone in subchondral, decrease the apoptosis of chondrocytes, down-regulate the expressions of active caspase-9, active caspase-3 and bax, and up-regulate the expression of bcl-2. In addition, LRWXG could up-regulate the expression of cyt-c in mitochondria, while down-regulate the expression of cyt-c in cytoplasm. These findings show that LRWXG inhibits cartilage degradation via an intrinsic bax-mitochondria cytochrome c-caspase pathway in OA.

Topics: Animals; Anterior Cruciate Ligament; Apoptosis Regulatory Proteins; Cartilage, Articular; Cytochromes c; Mitochondria; Molecular Weight; Osteoarthritis; Polysaccharides, Bacterial; Rabbits; Signal Transduction

Advanced glycation end products (AGEs) are an important mediator in osteoarthritis (OA) and cause apoptosis in articular chondrocytes. Mitochondrial function is involved in modulating apoptosis of articular chondrocytes. This study was performed to investigate the mechanism of AGEs-induced chondrocyte apoptosis. The ratio of apoptotic cell and cell viability was surveyed by TUNEL, MTT,LDH release assay. The reactive oxygen species was determined by the fluorescent probe 2', 7'-dichlorofluorescein diacetate. The expression of caspase-3 and cytochrome c was detected by Western blot. The mitochondrial membrane potential (▵Ψm) was evaluated by rhodamine-123 fluorescence. We found that AGEs induced apoptosis in primary rabbit chondrocytes, upregulation of ROS production, cytochrome c, and caspase-3 levels. Simultaneously, AGEs decreases the levels of ▵Ψm and ATP production; however, the antibody of AGEs (sRAGE) and antioxidant-N-acetylcys-teine (NAC) significantly reversed AGEs-induced the above damage thus to protect the cells from apoptosis. These observations suggested that the mechanism of AGEs-induced chondrocyte apoptosis was primarily via ROS production and mitochondria-mediated caspase-3 activation.

Topics: Animals; Apoptosis; Caspase 3; Cell Survival; Chondrocytes; Cytochromes c; Glycation End Products, Advanced; Male; Membrane Potential, Mitochondrial; Mitochondria; Osteoarthritis; Rabbits; Reactive Oxygen Species

Monosodium iodoacetate (MIA) is an inhibitor of glyceraldehyde-3-phosphate dehydrogenase activity, and causes dose-dependent cartilage degradation resembling the pathological changes of human osteoarthritis (OA). In this study, we assessed the apoptosis induced by MIA and clarified the underlying mechanisms using the primary rat chondrocytes. The apoptosis of primary rat chondrocytes was analyzed by flow cytometry. The levels of mitochondrial membrane potential (ΔΨm) were evaluated using fluorescence spectrophotometer. The production of reactive oxygen species (ROS) was determined by fluorescence spectrophotometer. Apoptosis-related protein cytochrome c and procaspase-3 expressions were examined by Western blotting. We found that MIA treatment induces apoptosis in chondrocytes, as confirmed by increases in the percent of apoptotic cells, up-regulation of cytochrome c and caspase-3 protein levels. Treatment with MIA increases ROS production and decreases the levels of ΔΨm. The antioxidant, N-acetylcysteine (NAC), significantly prevented the production of ROS, the reduction of ΔΨm, the release of cytochrome c and the activation of caspase-3. Further, NAC completely protected the cells from MIA-induced apoptosis. Together these observations suggest that the mechanisms of MIA-induced apoptosis are primarily via ROS production and mitochondria-mediated caspase-3 activation in primary rat chondrocytes.

Topics: Acetylcysteine; Animals; Apoptosis; Cartilage, Articular; Caspase 3; Cell Survival; Chondrocytes; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors; Femur Head; Iodoacetates; Male; Membrane Potential, Mitochondrial; Mitochondria; Osteoarthritis; Primary Cell Culture; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species

To determine the effects of the antioxidant resveratrol on the functions of human chondrocytes in osteoarthritis (OA).. Chondrocytes and cartilage explants were isolated from OA patients undergoing knee replacement surgery. Effects of resveratrol in the presence or absence of interleukin-1beta (IL-1beta) stimulation were assessed by measurement of prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) synthesis, cyclooxygenase (COX) activity, matrix metalloproteinase (MMP) expression, and proteoglycan production. To explore the mechanisms of action of resveratrol, its effects on mitochondrial function and apoptosis were examined by assessing mitochondrial membrane potential, ATP levels, cytochrome c release, and annexin V staining.. Resveratrol inhibited both spontaneous and IL-1beta-induced PGE(2) production by >20% (P < 0.05) and by 80% (P < 0.001), respectively; similarly, LTB(4) production was reduced by >50% (P < 0.05). The production of PGE(2) was inhibited via a 70-90% suppression of COX-2 expression and enzyme activity (P < 0.05). Resveratrol also promoted anabolic effects in OA explant cultures, by elevating proteoglycan synthesis and decreasing production of MMPs 1, 3, and 13. Pretreatment of OA chondrocytes with resveratrol blocked mitochondrial membrane depolarization, loss of mitochondrial biomass, and IL-1beta-induced ATP depletion. Similarly, IL-1beta-mediated induction of the apoptotic markers cytochrome c and annexin V was also inhibited by resveratrol. Exogenous addition of PGE(2) abolished the protective effects of resveratrol on mitochondrial membrane integrity, ATP levels, expression of apoptotic markers, and DNA fragmentation.. Resveratrol protects against IL-1beta-induced catabolic effects and prevents chondrocyte apoptosis via its inhibition of mitochondrial membrane depolarization and ATP depletion. These beneficial effects of resveratrol are due, in part, to its capacity to inhibit COX-2-derived PGE(2) synthesis. Resveratrol may therefore protect against oxidant injury and apoptosis, which are main features of progressive OA.

Topics: Adenosine Triphosphate; Analysis of Variance; Annexin A5; Antioxidants; Apoptosis; Blotting, Western; Cartilage; Chondrocytes; Cyclooxygenase 2; Cytochromes c; Dinoprostone; DNA Fragmentation; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Humans; Interleukin-1beta; Leukotriene B4; Matrix Metalloproteinases; Membrane Potential, Mitochondrial; Mitochondria; Osteoarthritis; Proteoglycans; Resveratrol; Reverse Transcriptase Polymerase Chain Reaction; Stilbenes