Human liver stem cell-derived extracellular vesicles modulate long non-coding RNA expression profile in an in vivo model of non-alcoholic steatohepatitis

Aim: Modifications in long non-coding RNA (lncRNA) expression are associated with inflammation and fibrosis in chronic liver diseases. It has been recently demonstrated that human liver stem cells (HLSCs) and their extracellular vesicles (EVs) can effectively reduce inflammation and fibrosis in a murine model of non-alcoholic steatohepatitis (NASH). Now it has been evaluated whether EVs can modify the expression of inflammation-related lncRNAs in NASH liver. Methods: To induce NASH, severe combined immunodeficient mice were fed with a methionine-choline-deficient diet for 4 weeks. After 2 weeks of diet, 2.5 × 109 EVs were intravenously injected twice a week. An array of 84 inflammation-related lncRNAs was performed on the RNA isolated from NASH livers, and the expression of 14 selected lncRNAs was then validated by real-time polymerase chain reaction (PCR) analysis. Expression levels of maternally expressed gene 3 (Meg3) were further evaluated in vitro, in an activated human hepatic immortalized stellate cell line (LX-2) stimulated with EVs. Results: The screening showed an altered lncRNA expression profile in the liver of NASH mice, in respect to control healthy mice. EV treatment modulated several inflammation-related lncRNAs in NASH livers. Real-time PCR validation of array results indicated that EVs restored to normal levels the expression of 10 lncRNAs altered in NASH. In particular, EV stimulation reduced Meg3 expression levels, which were increased in NASH as well as in activated LX-2. Conclusions: HLSC-EVs regulate the expression of inflammation-related lncRNAs impaired in NASH livers and in an in vitro model of liver fibrosis.