Oligochitosan-based nanovesicles for nonalcoholic fatty liver disease treatment via the FXR/miR-34a/SIRT1 regulatory loop.

Non-alcoholic fatty liver disease (NAFLD) is currently a common chronic liver disease worldwide. By now, however, there isn't any FDA-approved specific drug for NAFLD treatment. It has been noticed that farnesoid X receptor (FXR), miR-34a and Sirtuin1 (SIRT1) is related to the occurrence and development of NAFLD. A oligochitosan-derivated nanovesicle (UBC) with esterase responsive degradability was designed to co-encapsulate FXR agonist (obeticholic acid, OCA) and miR-34a antagomir (anta-miR-34a) into the hydrophobic membrane and the center aqueous lumen of nanovesicles, respectively, by dialysis method. The action of UBC/OCA/anta-miR-34a loop on the regulation of lipid deposition via nanovesicles was evaluated on high-fat HepG2 cells and HFD-induced mice. The obtained dual drug-loaded nanovesicles UBC/OCA/anta-miR-34a could enhance the cellular uptake and intracellular release of OCA and anta-miR-34a, leading to the reduced lipid deposition in high-fat HepG2 cells. In NAFLD mice models, UBC/OCA/anta-miR-34a achieved the best curative effect on the recovery of body weight and hepatic function. Meanwhile, in vitro and vivo experiments validated that UBC/OCA/anta-miR-34a effectively activated the expression level of SIRT1 by enhancing the FXR/miR-34a/SIRT1 regulatory loop. This study provides a promising strategy for constructing oligochitosan-derivated nanovesicles to co-deliver OCA and anta-miR-34a for NAFLD treatment. STATEMENT OF SIGNIFICANCE: This study proposed a strategy to construct oligochitosan-derivated nanovesicles to co-deliver obeticholic acid and miR-34a antagomir for NAFLD treatment. Based on the FXR/miR-34a/SIRT1 action loop, this nanovesicle effectively exerted a synergetic effect of OCA and anta-miR-34a to significantly regulate lipid deposition and recover liver function in NAFLD mice.