Epigenetic DNA methylation of Zbtb7b regulates the population of double-positive CD4+CD8+ T cells in ulcerative colitis

Abstract

Background and aims Ulcerative colitis (UC) is a heterogeneous disorder with complex pathogenesis. Therefore, in the present study, we aimed to assess genome-wide DNA methylation changes associated explicitly with the pathogenesis of UC. Methods DNA methylation changes were identified by comparing UC tissues with healthy controls (HCs) from the GEO databases. The candidate genes were obtained and verified in clinical samples. Moreover, the underlying molecular mechanism related to Zbtb7b in the pathogenesis of UC was explored using the dextran sodium sulfate (DSS)-induced colitis model. Results Bioinformatic analysis from GEO databases confirmed that Zbtb7b, known as Th-inducing POZ-Kruppel factor (ThPOK), was demethylated in UC tissues. Then, we demonstrated that Zbtb7b was in a hypo-methylation pattern through the DSS-induced colitis model (P = 0.0357), whereas the expression of Zbtb7b at the mRNA and protein levels was significantly up-regulated in the inflamed colonic tissues of UC patients (qRT-PCR, WB, IHC: P < 0.0001, P = 0.0079, P < 0.0001) and DSS-induced colitis model (qRT-PCR, WB, IHC: P < 0.0001, P = 0.0045, P = 0.0004). Moreover, the expression of Zbtb7b was positively associated with the degree of UC activity. Mechanically, over-expression of Zbtb7b might activate the maturation of CD4+T cells (FCM, IF: P = 0.0240, P = 0.0003) and repress the differentiation of double-positive CD4+CD8+T (DP CD4+CD8+T) cells (FCM, IF: P = 0.0247, P = 0.0118), contributing to the production of inflammatory cytokines, such as TNF-α (P = 0.0005, P = 0.0005), IL-17 (P = 0.0014, P = 0.0381), and IFN-γ (P = 0.0016, P = 0.0042), in the serum and colonic tissue of DSS-induced colitis model. Conclusions Epigenetic DNA hypo-methylation of Zbtb7b activated the maturation of CD4+T cells and repressed the differentiation of DP CD4+CD8+ T cells, resulting in the production of inflammatory cytokines and colonic inflammation in UC. Therefore, Zbtb7b might be a diagnostic and therapeutic biomarker for UC, and hypo-methylation might affect the biological function of Zbtb7b.

Edible exosome-like nanoparticles from Portulaca oleracea L prevent DSS-induced colitis via the promotion of double-positive CD4 + CD8 + T cells

“…Moreover, DP CD4 + CD8 + T cells have functions of intestinal in ammation repression, IL-10 production, and bacterial invasion prevention 49 . We have previously discovered that the amount of DP CD4 + CD8 + T cells in colon tissues is substantially decreased compared the DSS-induced colitis with the health control 35 . Consequently, DP CD4 + CD8 + T cells could be an effective target for the treatment of colitis.…”

“…As reported, DP CD4 + CD8 + T cells can maintain a steady-state of the gut mucosa, and inhibit proin ammatory cytokine release during pathogenic infection 36 . Moreover, we previously demonstrated that the population of DP CD4 + CD8 + T cells was signi cantly decreased in UC mice colon samples 35 . Consequently, we investigated whether the oral administration of PELNs have an effect in the differentiation of DP CD4 + CD8 + T cells in mice colitis.…”

“…The RNA extraction and qRT-PCR were carried out as previously described 25,35 . RNA was extracted from colon samples using the TRIzol Reagent (Thermo, USA).…”

“…FCM was used to analysis the population DP CD4 + CD8 + T cells in the colon samples. The procedure carried out as previously described 35 .…”

“…IF was performed to detect the population DP CD4 + CD8 + T cells in the colon samples as previously described 25,35 .…”