miRNA profiling of Macaca mulatta colonic epithelium samples from chronic SIV infected rhesus macaques

The study describes miRNA expression in colonic epithelium of chronic SIV-infected rhesus macaques. We profiled and characterized miRNA/mRNA expression exclusively in colonic epithelium (CE) of 12 chronically SIV-infected and 8 control rhesus macaques (RMs). About 46 miRNAs were differentially expressed (DE) (20-up and 26-down) in CE during chronic SIV infection. Using TargetScan, we bioinformatically crossed the predicted targets of DE miRNAs to genome-wide transcriptomic data and identified several critical miRNA-mRNA pairings that suggested miRNA-mediated regulation of aberrant epithelial gene expression in CE. Immunofluorescence, luciferase reporter and miRNA overexpression studies confirmed the ability of miR-130a and miR-212 to bind the 3’ UTR and downregulate protein expression of occludin (OCLN) and peroxisome proliferator activator receptor gamma (PPAR), respectively, two proteins with pivotal roles in epithelial barrier function. MiR-130a and miR-212 overexpression in Caco-2 cells significantly reduced transepithelial electrical resistance (TEER). Interestingly, delta-9-tetrahydrocannabinol (9-THC) treatment restored TEER to levels observed with control miRNA mimic. Finally, ex-vivo 9-THC treatment of colon tissue from chronically SIV-infected RMs significantly increased PPAR gene 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 PPAR protein 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. Colonic epithelium samples were isolated from 12 chronically SIV-infected and 8 uninfected control rhesus macaques.