METTL14 regulates inflammation in ulcerative colitis via the lncRNA DHRS4-AS1/miR-206/A3AR axis.

As a chronic inflammatory bowel disease, the pathogenesis of ulcerative colitis (UC) has not been fully elucidated. N6-methyladenosine (m6A) modification, observed in various RNAs, is implicated in inflammatory bowel diseases. Methyltransferase-like 14 (METTL14) is the major subunit of the methyltransferase complex catalyzing m6A modifications. Here, we designated to examine the regulatory effects and mechanisms of METTL14 on long non-coding RNA (lncRNA) during UC progression. METTL14 knockdown decreased cell viability, promoted apoptosis, increased cleaved PARP and cleaved Caspase-3 levels, while reducing Bcl-2 levels. METTL14 knockdown also led to a significant increase in NF-κB pathway activation and inflammatory cytokine production in the Caco-2 cells treated with TNF-α. Moreover, the suppression of METTL14 aggravated colonic damage and inflammation in our dextran sulfate sodium (DSS)-induced murine colitis model. METTL14 silencing suppressed DHRS4-AS1 expression by reducing the m6A modification of DHRS4-AS1 transcripts. Furthermore, DHRS4-AS1 mitigated inflammatory injury by targeting the miR-206/adenosine A3 receptor (A3AR) axis. DHRS4-AS1 overexpression counteracted the enhancing impact of METTL14 knockdown on TNF-α-induced inflammatory injury in Caco-2 cells. In conclusion, our findings suggest that METTL14 protects against colonic inflammatory injury in UC via regulating the DHRS4-AS1/miR-206/A3AR axis, thus representing a potential therapeutic target for UC.