Long Noncoding RNA PMS2L2 Downregulates miR-24 through Methylation to Suppress Cell Apoptosis in Ulcerative Colitis.

ABSTRACT

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease characterized by chronic inflammation of the colon. It has been reported that PMS2L2 plays protective roles in inflammatory injury. This study aimed to investigate the role of the long noncoding RNA PMS2L2 in UC. METHODS: Sixty-two patients with UC as well as 62 age- and gender-matched healthy controls were enrolled. Expressions of PMS2L2 and miR-24 in plasma from UC patients and healthy controls were determined by RT-qPCR. The interaction between PMS2L2 and miR-24 was predicted by bioinformatics and confirmed by RNA immunoprecipitation and RNA pull-down. The role of PMS2L2 in the regulation of miR-24 gene methylation was analyzed by methylation-specific PCR. The effects of PMS2L2 and miR-24 on the expressions of apoptosis-related proteins were detected by Western blots. RESULTS: PMS2L2 was downregulated in the plasma of UC patients compared to that in age- and gender-matched healthy control. In human colonic epithelial cells (HCnEpCs), PMS2L2 overexpression inhibited miR-24 expression via promoting the methylation of miR-24 gene. In contrast, miR-24 overexpression failed to affect PMS2L2. In the detection of cell apoptosis, PMS2L2 overexpression could promote the expression of Bcl-2 and inhibit Bax, cleaved-caspase-3, and cleaved-caspase-9 expressions stimulated by LPS. Flow cytometer revealed that PMS2L2 elevation suppressed the apoptosis of HCnEpCs induced by LPS, but miR-24 aggravated the apoptosis. PMS2L2 overexpression rescued the detrimental effect of miR-24 on cell apoptosis. CONCLUSION: PMS2L2 may downregulate miR-24 via methylation to suppress cell apoptosis in UC.