Biological Functions of Selenoprotein Iodothyronine Deiodinase and its Expression in Osteoarthritis.

Objective Iodothyronine deiodinases (DIOs) are important selenoproteins that play a key role in the bone and joint diseases. Osteoarthritis (OA) is the most prevalent joint disease especially in elders. This bioinformatic analysis was performed to explore the role of DIOs in OA pathogenesis. Methods The biological functions of selenoprotein DIOs were analyzed by bioinformatic techniques, including GenCLip 3.0, Database for Annotation, Visualization and Integrated Discovery (DAVID), STRING, Cytoscape, and Network Analyst. The expression of DIOs in the healthy individuals and OA patients was determined by mining OA-related microarray data in the gene expression omnibus (GEO) database of National Center for Biotechnology Information and performing a Meta-analysis of the data with Review Manager 5.3. Results Cluster analysis revealed that the function of the DIOs was associated with thyroid hormone receptor and iodothyronine; GO analysis showed that DIOs were mainly involved in biological processes, such as ethanol metabolism and phenol-containing compound metabolism and primarily involved in the cytochrome P450 metabolism of exogenous organisms and thyroid hormone signaling; SULT1A1 was the core node of the PPI network; miRNAs and thyroid hormones had some iterations with DIO1 and DIO2 ; Meta-analysis showed that DIO3 expression was significantly up-regulated in OA patients ( SMD = 0.31, 95% CI : 0.03, 0.59, P = 0.03). Conclusions The main biological functions of DIOs were closely associated with the regulation of thyroid hormone. And the up-regulated expression of DIO3 may have crucial impact on the occurrence of OA.