DNMT3a-Mediated Enterocyte Barrier Dysfunction Contributes to Ulcerative Colitis via Facilitating the Interaction of Enterocytes and B Cells

Figure 4

Overexpression of TNFSF13 in IECs induces B cell differentiation via TACI. (a) GSE81211 dataset was used to analyze the genes of high DNA methylation levels in UC, and the screened genes were displayed in heatmap. (b) The intestinal epithelial tissues from mice in the sham and DSS group were collected. TNFSF13 DNA methylation level, mRNA level, and protein level were evaluated. (c) IECs were transfected with pc-TNFSF13 or pc-NC following the treatment of LPS (1 μg/mL) for 48 h. Cells were allocated into 4 groups: IECs, IECs+LPS, IECs-pc-NC+LPS, and IECs-pc-TNFSF13+LPS. The methylation level and mRNA level in IECs and protein level of TNFSF13 in the supernatants were examined. (d) The si-TACI or si-NC was transfected into B cells, and the TACI mRNA and protein levels were detected. (e) Next, IECs with or without pc-TNFSF13 transfection were cocultured with B cells with or without si-TACI transfection. The divided groups were as follows: IECs+B+LPS (TACI was normally expressed in B cells), IECs+B-si-TACI+LPS (TACI was knockdown in B cells), IEC-pc-TNFSF13+B+LPS (TACI was normal expressed in B cells, and TNFSF13 was overexpressed in IECs), and IEC-pc-TNFSF13+B-si-TACI+LPS (TACI was knockdown in B cells, and TNFSF13 was overexpressed in IECs) groups. The numbers of CD1d+ B cells and CD138+ B cells were measured by flow cytometry. (f) IL-10, TGF-β, IL-6, and TNF-α levels in cell supernatants were examined. , vs. sham or IEC or B+si-NC or LPS group; ^### vs. IECs-pcNC+LPS or LPS+si-TACI group.

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