METTL3‐mediated m⁶A modification of circPRKAR1B promotes Crohn's colitis by inducing pyroptosis via autophagy inhibition

Abstract

BackgroundThe roles of circRNA and N6‐methyladenosine (m6A) methylation in Crohn's disease (CD) have drawn much attention. Therefore, this investigation aimed to discover how the m6A modification of circRNAs contributes to CD progression.MethodsThe study performed circRNA sequencing on colon samples from four CD patients and four normal controls (NCs) to screen for dysregulated circRNAs. Quantitative real‐time polymerase chain reaction (qRT‐PCR) was performed to validate the candidate circRNA expression and determine its correlation to CD‐associated inflammatory indicators. In vivo and in vitro investigations were conducted to examine the functions and pathways of circPRKAR1B in CD, besides investigating the m6A modification role in circRNA expression modulation.ResultsThe RNA‐seq revealed that hsa_circ_0008039 (circPRKAR1B) was the most significant upregulated circRNA and was identified as the candidate circRNA for further examinations. Relative circPRKAR1B expression was significantly upregulated in CD colon tissues and closely related to CD‐associated inflammatory indices. The circPRKAR1B expression and function were regulated by methyltransferase‐like 3 (METTL3)‐mediated m6A methylation. In vitro studies indicated that circPRKAR1B promoted pyroptosis mediated by NLRP3 inflammasome (NLRP3; nucleotide‐binding oligomerization domain, leucine‐rich repeat and pyrin domain‐containing 3) and impaired autophagy by interacting with the RNA‐binding protein (RBP) SPTBN1, (SPTBN1; spectrin beta, non‐erythrocytic 1). The in vivo investigations revealed the treatment effects of si‐circPRKAR1B and si‐METTL3 in colitis models of IL‐10‐deficient mice.ConclusionOur study reveals that METTL3‐mediated m6A modification of circPRKAR1B promotes Crohn's colitis by aggravating NLRP3 inflammasome‐mediated pyroptosis via autophagy impairment in colonic epithelial cells.

Fibroblast-like synoviocytes-derived exosomal circFTO deteriorates rheumatoid arthritis by enhancing N6-methyladenosine modification of SOX9 in chondrocytes

“…Additionally, Hu et al propose that WTAP-mediated m6a modification contributes to improved stability for circCCAR1 [ 24 ]. Furthermore, METTL3 has been observed regulating various circRNAs such as cirRIMS2 [ 25 ], circPRKAR1B [ 26 ], and cirQSOX1 [ 27 ] through its involvement in mediating m6A methylation. Considering these findings, we hypothesized that circFTO may interact with MTC to influence self-methylation or modifying other RNAs.…”

Characterization of PANoptosis-related genes in Crohn’s disease by integrated bioinformatics, machine learning and experiments

“…A comparative study showed that necroptosis is active in children with CD and can strengthen the inflammatory process 6 . Aggravation of NLRP3 inflammasome-mediated pyroptosis promotes Crohn’s colitis and gasdermin-E-mediated pyroptosis is involved in CD pathogenesis through the release of proinflammatory cytokines 7 , 8 . There is evidence at the single-cell transcriptome level that ferroptosis participates in the imbalance of intestinal microenvironment homeostasis in CD patients and inhibition of ferroptosis can reconstruct intestinal barrier 9 , 10 .…”