Expression of G α q Is Decreased in Lymphocytes from Primary Sjögren's Syndrome Patients and Related to Increased IL-17A Expression.

Primary Sjogren's syndrome (pSS) is a rheumatic disease characterized by the destruction of salivary and lacrimal glands, and its pathogenesis mechanism remains unclear. G alpha q is the alpha-subunit of the heterotrimeric Gq protein. Researches demonstrated that G alpha q was involved in the pathogenesis regulation of several rheumatic diseases. This study explored the role of G alpha q in pSS. G alpha q mRNA levels in peripheral blood mononuclear cells (PBMCs) from 39 patients and 26 healthy controls (HCs) were investigated using real-time PCR. IL-17A serum concentrations in 22 pSS patients and 23 HCs were tested by ELISA, and the clinical significance of G alpha q was analyzed. The association of G alpha q with interleukin-17A (IL-17A) expression was also analyzed in patients with pSS. We showed that G alpha q expression in PBMCs from patients with pSS was significantly lower than that in PBMCs from HCs. G alpha q expression level was closely associated with pSS disease activity. Furthermore, a negative association was also found in IL-17A and G alpha q expression level. These data suggest that G alpha q is involved in pSS pathogenesis regulation, possibly due to its regulation of Th17. These results provide new insights into the pSS pathogenesis mechanism involving abnormal Th17 regulation.