Polydatin regulates the apoptosis and autophagy of fibroblasts obtained from patients with ankylosing spondylitis.

The development of ankylosing spondylitis (AS) occurs due to excessive proliferation of fibroblasts. Polydatin, a monomeric compound isolated from a traditional Chinese medicine polygonum cuspidatum, exhibits anti-inflammatory and anti-arthritic effects. However, the mechanisms underlying the regulatory effects of polydatin on the proliferation, apoptosis and autophagy of fibroblasts obtained from patients with AS remain unclear. The aim of this study was to investigate the therapeutic effects of polydatin on symptoms associated with AS. Multiple cellular and molecular biology experiments were performed in the present study, such as cell viability assay, western blotting, flow cytometry, monodansylcadaverine (MDC) staining and immunofluorescence assays. In the present study, the results revealed that polydatin induced the apoptosis of fibroblasts isolated from patients with AS by upregulating the expression of active caspase-3 and Bax, and downregulating the expression of Bcl-2. Meanwhile, polydatin was revealed to enhance the autophagy of fibroblasts by increasing the expression levels of LC3II, Beclin 1 and Atg5. The results of MDC and immunofluorescence assays further demonstrated that polydatin significantly induced the formation of autophagosomes in fibroblasts. Furthermore, polydatin-induced apoptosis and autophagy were markedly inhibited following treatment with the autophagy inhibitor, 3-Methyladenine (3-MA). In conclusion, the results of the present study indicated that polydatin induces the apoptosis and autophagy of fibroblasts obtained from patients suffering from AS, and that polydatin may represent a therapeutic agent for the future treatment of patients with AS.