Expression and localization of immunoregulatory gene G protein subunit Alpha Q in different tissues of collagen-induced arthritis rats

Abstract

Objective To investigate the expression and localization of the immunoregulatory gene G protein subunit Alpha Q (Gnαq) in different tissues of collagen-induced arthritis (CIA) rats. Methods We investigated the expression and localization of Gnαq in the heart, liver, spleen, lung, kidney, and joints of the CIA rat model. The Gnαq mRNA and protein expression levels in these tissues of rats from CIA and control groups were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting, respectively. The cellular localization of Gnαq protein was determined by immunohistoche-mistry (IHC) assays. Factorial analysis of variance was used for statistical analysis. Results The CIA rat model was successfully built-up. The sequence homology of Gnαq PCR products was 99.34%. Gnαq was expressed at various levels in different tissues of rats from the groups. The levels of Gnαq mRNA (4.406±0.480 and 2.412±0.186) and protein (99.8±9.6 and 65.9±5.0) in the joints and lungs of CIA rats were significantly higher than those in other tissues, the difference was statistically significant (F=1 244 538.874, 154 377.357, P<0.01). Positive expression signals for Gnαq were detected in various tissues of CIA and control rats, among which strong positive signals were detected in joint fibroblast-like synoviocytes (FLSs), endothelial cells, stromal cells, and macrophages. Conclusion Our results further confirms the involvement of Gnαq in the onset and devel-opment of inflammatory responses in RA, suggesting that Gnαq may be a new therapeutic target for RA. Key words: Arthritis, rheumatoid; Spleen; Joint