Fig 2: MiR-19a-3p regulated the expression of YTHDF2 by targeting its mRNA 3'-UTR. a The degree of global m6A RNA methylation level of total RNA in 36 SLE samples was higher than that of the 25 healthy controls (P < 0.05). b Predicted the potential miRNAs targeting the 3'-UTR of YTHDF2 by TargetScan, and miR-19a had binding sites for YTHDF2. c WB (Western blot) analysis demonstrated that miR-19a-3p could significantly inhibit the expression of YTHDF2 in PBMCs, suggesting that miR-19a-3p is involved in the regulation of YTHDF2 mRNA. d Schematic diagram of the binding sites of miR-19a-3p in the 3'-UTR of YTHDF2 mRNA. The mutant was produced at the 3'-UTR of YTHDF2 mRNA. The 3'-UTR sequence of the YTHDF2 mRNA containing the wild-type (or mutants) of the miR-19a-3p binding sequence was cloned into the downstream vector of the psicheck2-control luciferase reporter gene. e The interaction of YTHDF2 with miR-19a-3p was tested by luciferase reporter assay. Luciferase reporter gene assays was to measure the effect of miR-19a-3p on reporters, such as psicheck2-YTHDF2-wt and psicheck2-YTHDF2-mut in 293T cells. The experiment was repeated at least three times. The results are represented as the mean ± SD (n = 3). ns, no significance, **P < 0.01; ***P < 0.001

Fig 3: Schematic diagram of the regulatory mechanism of circGARS in the pathogenesis of SLE. CircGARS directly combined with miR-19a regulate the expression of A20 to influence the immune responses regulated by the NF-?B pathway as a negative feedback mechanism. Moreover, circGARS enhanced the transcriptional level by directly binding to m6A modification proteins. In addition, miR-19a regulated A20 degradation by downregulating YTHDF2

Fig 4: HIF-1α mRNA is m6A-modified and bound by YTHDF2. (A) The HeLa cells were lysed and incubated with either m6A or YTHDF2 antibodies; then, bound HIF-1α mRNA was analysed by qPCR. (B) The HeLa and H1299 cells were then transfected with either control or PBRM1 siRNAs and incubated with the IgG control or YTHDF2 antibodies before analysis of HIF-1α mRNA levels. The means and standard deviations are plotted with Student’s t-test significance indicated (** p ≤ 0.01). (C) The HeLa or H1299 cells were transfected with control, PBRM1 or YTHDF2 siRNAs and either DMSO or MG132 for 3 h; then, the cells were lysed and protein levels were determined by Western blotting. +, signifies specific treatment.