PKCa Agonists Enhance the Protective Effect of Hyaluronic Acid on Nitric Oxide-Induced Apoptosis of Articular Chondrocytes in Vitro

Abstract

<em><span style="font-size: xx-small;">Objective(s): </span></em> <span style="font-family: Cambria,Cambria; font-size: xx-small;">Protein kinase C (PKCα) is involved in modulating articular chondrocytes apoptosis induced by nitric oxide (NO). Hyaluronic acid (HA) inhibits nitric oxide-induced apoptosis of articular chondrocytes by protecting PKCα, but the mechanism remains unclear. The present study was performed to investigate the effects and mechanisms of PKCα regulate protective effect of hyaluronic acid. </span>

Materials and Methods <span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">The ratio of apoptotic cell and cell viability was surveyed by PCNA and MTT assay. The expression of caspase-3 was determined by real-time PCR and western blot. </span></span> Results: <span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">It was showed that HA was able to reduce the nuclei fragment and PCNA expression, and NO-induced articular apoptosis blocked by HA, pretreated chondrocytes with PMA, HA significantly inhibits the activation of caspase-3 induced by NO, but pretrement with CHR, HA significantly incresed the expression of caspase-3. </span></span> Conclusion: <span style="font-family: Cambria,Cambria; font-size: xx-small;"><span style="font-family: Cambria,Cambria; font-size: xx-small;">The results may be showed that PKCa regulate the expresion of caspase-3, which contribute to the apoptosis of chondrocytes induced by NO. PKC α agonists enhance the protective effect of hyaluronic acid on nitric oxide-induced articular chondrocytes apoptosis. </span></span>