Jiangu Recipe Suppresses ER Stress-Induced Apoptosis and Inhibits Extracellular Matrix Degradation in Chondrocytes through Upregulating SIRT1 Expression.

Objective: This study aimed to explore the effects of Jiangu Recipe (JGR) on chondrocyte responses under tert-Butyl hydroperoxide (TBHP)-induced oxidative stress, specifically focusing on apoptosis and extracellular matrix (ECM) degradation.

Methods: Chondrocytes were treated with varying JGR concentrations, and cell viability was assessed. The impact of JGR on TBHP-induced apoptosis and protein expression levels of apoptosis- related molecules (Bcl-2, Bax, and cleaved caspase-3) and ECM components (Collagen II, Aggrecan, MMP-13) was evaluated.

Results: JGR exhibited protective effects against oxidative stress in chondrocytes. Moreover, it maintained cell viability under tert-butyl hydroperoxide (TBHP) induction, suppressing apoptosis (Bax, cleaved caspase-3) and enhancing anti-apoptotic Bcl-2. JGR also attenuated extracellular matrix (ECM) degradation, promoting Collagen II and Aggrecan while reducing MMP-13 expression. Investigating endoplasmic reticulum (ER) stress, it was found that JGR downregulated TBHP-induced GRP78, CHOP, ATF4, p-PERK, and p-eIF2α, thus indicating ER stress modulation. SIRT1 played a key role, as JGR upregulated SIRT1, mitigating TBHP-induced downregulation. SIRT1 knockdown reversed JGR's protective effects, highlighting its crucial role in JGR-mediated responses.

Conclusion: Our findings suggest that JGR mitigated TBHP-induced chondrocyte apoptosis and ECM degradation, highlighting its potential therapeutic application in osteoarthritis. Mechanistically, our study highlights that SIRT1 plays a crucial role in mediating the protective effects of JGR against ER stress-induced chondrocyte apoptosis and ECM degradation, providing a foundation for further clinical exploration in managing osteoarthritic conditions.