Mirt2 functions in synergy with miR-377 to participate in inflammatory pathophysiology of Sjögren's syndrome.

Background: The interaction of long non-coding RNAs (lncRNAs)-microRNAs (miRs) exerts crucial functions in mediating inflammatory reaction. It is still unclear whether myocardial infarction associated transcript 2 (Mirt2)-miR-377 mediates the inflammatory pathogenesis in Sjögren's syndrome (SS). Methods: The inflammatory lesion model was established by stimulating salivary gland epithelial cells (SGECs) by interferon gamma (IFN-γ). Mirt2- and/or miR-377-transfected SGECs, as well as their negative controls, were applied to investigate the biological functions in inflammation. Cell viability and apoptosis were examined using commercial kits. Western blot was applied to quantify protein level, and enzyme-linked immuno sorbent assay (ELISA) was used to value the secretion of cytokines. Results: The up-regulation of Mirt2 was observed in IFN-γ-treated SGECs. Mirt2 overexpression restored the expression of miR-377 which was repressed by IFN-γ. However, miR-377 silence abolished the protective effect on cell viability, inhibitory effect on apoptosis and prohibitive role in pro-inflammatory factors. Mirt2 diminished the phosphorylated expression of crucial regulators while miR-377 silence restored the phosphorylation in IFN-γ-treated SGECs. Conclusion: Mirt2 was elevated in IFN-γ-treated SGECs and then up-regulated miR-377 in response to inflammatory lesions. Mechanically, in synergy with miR-377 Mirt2 blocked IFN-γ-evoked activation of NF-κB and JAK/STAT signalling pathway.