| Popis: |
Intestinal epithelial barrier dysfunction is a well-known sequela of HIV/SIV infection that persists despite anti-retroviral therapy. Although, inflammation is a triggering factor, the underlying molecular mechanisms remain unknown. Emerging evidence suggests that epithelial barrier function is epigenetically regulated by inflammation induced microRNAs. Accordingly, we profiled and characterized miRNA/mRNA expression exclusively in colonic epithelium (CE) and identified 46 differentially expressed (DE) miRNAs (20-up and 26-down) in chronically SIV-infected rhesus macaques (RMs) (Macaca mulatta). We bioinformatically crossed the predicted miRNA targets to transcriptomic data and characterized miR-130a and miR-212 as both were predicted to interact with critical epithelial barrier associated genes. Next, we characterized peroxisome proliferator activator receptor gamma (PPARγ) and occludin (OCLN), predicted targets of miR-130a and miR-212 respectively, as their downregulation has been strongly linked to epithelial barrier disruption and dysbiosis. Immunofluorescence, luciferase-reporter and overexpression studies confirmed the ability of miR-130a and miR-212 to decrease protein expression of OCLN and PPARγ, respectively and reduce transepithelial electrical resistance (TEER). Since delta-9-tetrahydrocannabinol (Δ(9)-THC) exerted protective effects in the intestine in our previous studies, we successfully used it to reverse miR-130a and miR-212 mediated reduction in TEER. Finally, ex-vivo Δ(9)-THC treatment of colon tissue from chronically SIV-infected RMs significantly increased PPARγ expression. Our findings suggest that dysregulated miR-130a and miR-212 expression in CE during chronic HIV/SIV infection can facilitate epithelial barrier disruption by downregulating OCLN and PPARγ expression. Most importantly, our results highlight the beneficial effects of cannabinoids on epithelial barrier function in not just HIV/SIV but potentially other chronic intestinal inflammatory diseases. |
