Biological Functions of Selenoprotein Glutathione Peroxidases (GPXs) and their Expression in Osteoarthritis.

PURPOSE: In order to further study the biological functions of glutathione peroxidases (GPXs) and their expression level in patients with osteoarthritis (OA), we fully explored the potential relationship between GPXs and OA. This will provide new ideas for basic biological studies and therapeutic strategies for OA patients.

PATIENTS AND METHODS: In this study, bioinformatics techniques were used to explore the biological functions of five GPXs. The core genes related to the biological functions of GPXs were identified by constructing a protein-protein interaction network (PPI). In addition, we utilized microarray data in public databases to analyze the expression levels of GPXs in OA patients and healthy controls. Finally, we used quantitative real-time polymerase chain reaction (qRT-PCR) to detect the expression of GPXs in OA patients and controls to validate our bioinformatic analysis results.

RESULTS: Enrichment analysis showed GPXs were mainly enriched in the glutathione metabolic pathway and participate in the biological process of oxidative stress response, and further play an antioxidant role. The PPI network indicated that superoxide dismutase 1 (SOD1), superoxide dismutase 2(SOD2) and catalase (CAT) were the core proteins of this network. GPX1 was regulated by the greatest number of miRNAs. Experiments showed that the expression of GPX1 was elevated in OA patients compared with controls.

CONCLUSION: GPXs play an important antioxidant role in oxidative stress response. The expression of GPX1 was elevated in peripheral blood mononuclear cells (PBMCs) of OA patients. The changes of GPXs in OA patients may regulate the level of oxidative stress, which may influence synovial lesions and chondrocyte apoptosis.