MicroRNA-16for The Treatment Of Experimental Murine Colitis Model Induced By TNBS

Inflammatory bowel disease (IBD) is a chronic, relapsing and remitting inflammatory disorder within the gastrointestinal tract. Although the precise pathogenesis of IBD remains unclear, it is generally accepted that the combination of genetic susceptibility, environmental triggers and immune imbalance results in chronic intestinal inflammation.MicroRNA (miRNA) is a class of non-coding single-stranded RNA molecules with21-25nucleotides in length. Recent studies have found that miRNAs can regulate a series of IBD-related gene expression and play a very important role in the development of IBD, indicating that miRNAs could be the targets or potential drugs for the treatment of IBD.In this paper, we studied the effects of miR-16on the treatment of IBD using experimental murine colitis model induced by TNBS (Trinitro-Benzene-Sulfonic Acid). Firstly, we respectively built the3’-UTR of TNF-a and IL-12p40, which contains the AU-rich elements into luciferase expression vector. At the cellular level, we validated whether miR-16is able to bind the3’-UTR of TNF-a and IL-12p40by luciferase reporter system. In addition, we transfected precursor or inhibitor of miR-16into activated peritoneal macrophages to detect the protein expressions of TNF-a and IL-12p40. The experiments in vitro showed that miR-16could bind the the3’-UTR of TNF-a and IL-12p40and negatively regulate the mRNA expression and protein expression of TNF-a and IL-12p40, which demonstrates that TNF-a and IL-12p40are the common downstream targets of miR-16.Then, miR-16precursor was delivered to the colon macrophages by galatose modified low molecular weight chitosan (G-LMWC) to study the treatment effects of miR-16in experimental mouse colitis model induced by TNBS. The results indicated that G-LMWC could target into the colon macrophages that are the main source of TNF-a, IL-12and IL-23. The expressions of TNF-a, IL-12p70and IL-23significantly decreased in colon tissues of mouse colitis model. Other biomarkers also indicated that the intestinal inflammation was significantly alleviated. All the results taken together demonstrate that miR-16precursor with multi-target regulation will be potentially applied in the clinical therapy of IBD in the future.