Extracorporeal shock wave protects chondrocytes against interleukin-1β-induced apoptosis and promotes autophagy in vitro

Abstract

Osteoarthritis (OA) is a common joint disease, but there is no effective treatment except surgery at present. Extracorporeal shock wave (ESW) is an emerging therapy widely used in various medical fields. In this study, we mainly investigated the effects of ESW on apoptosis and autophagy of osteoarthritic chondrocytes by analyzing the cell apoptosis and the expression of autophagy markers' mRNAs and proteins, respectively. Primary chondrocytes were isolated from articular cartilage tissue of rats. Results showed that ESW effectively inhibited the interleukin-1β-induced (IL-1β-induced) chondrocyte apoptosis. Moreover, ESW treatment elevated the mRNA and the protein expression levels of Beclin 1, Atg5, LC3B, and Collagen II. Beclin 1 plays a key role in autophagy, positively regulating autophagic activity. Atg5 is a marker of autophagic activity, and LC3 is a specific marker of autophagosome. Collagen II is an important indicator to judge the functional activity of chondrocytes. In contrast, the mRNA and the protein expression levels of P62, which is a measure of autophagic flux and is thought to be negatively correlated with autophagic degradation, were decreased in the ESW treated cells. This study reveals the role of ESW in promoting chondrocyte autophagy and suppressing cell apoptosis. Thus, ESW may protect chondrocytes against IL-1β-induced apoptosis and promote autophagy in an in vitro model of osteoarthritis.