Cell-specific expression and function patterns of microRNA-150-5p in liver fibrogenesis

MicroRNAs (miRNAs) are endogenous and small non-coding RNA molecules that mediate post-transcriptional gene suppression by incomplete matches with their host mRNAs. Recent studies have highlighted that miRNAs are involved in the pathology of liver lipid metabolism, metabolic inflammation, oxidative stress, chronic liver injury, regeneration and fibrogenesis. During liver fibrosis, miRNAs are simply categorized into pro-fibrotic or anti-fibrotic miRNAs according to their expression alterations in one liver cell type especially hepatic stellate cells (HSCs). Our current study observed a miRNA, termed miR-150-5p, exhibited cell-specific expression pattern in liver fibrosis. Although the expression level of miR-150-5p in fibrotic liver tissues or hepatocytes was significantly enhanced, it was notably down-regulated in HSCs in the context of liver fibrosis. Perturbation of miR-150-5p evidently affected the cell viability of HSCs but had no obvious effect on hepatocytes. While overexpression of miR-150-5p could sensitize the apoptosis of hepatocytes in the presence of pro-apoptotic factors. Further investigations revealed that miR-150-5p mimic treatment had a larger influence on the transcriptomic stability of HSCs but a minor effect on hepatocytes. The genes related to anti-apoptosis or pro-proliferation were decreased and genes associated with pro-apoptosis or anti-proliferation were increased after miR-150-5p overexpression, which might be the potential targets of miR-150-5p overexpressed in HSCs. Collectively, our study provide a strong supporting evidence that some miRNAs may express or function in a cell-specific pattern in the backdrop of liver fibrosis. MiR-150-5p mimics or controls were transfected into LX-2 and QSG cells (n=2 for each group) for 48 hours. Total RNA was isolated using Trizol reagent (Invitrogen, USA). Agilent 2100 Bioanalyzer (Agilent Technologies, USA) was used to evaluate the RNA quality. One μg RNA was used to generate cDNA library based on TruSeq RNA Sample Prep Kit v2 (Illumina, USA) according to the manufacturer’s instructions. Then the cDNA libraries were sequenced on the Illumina HiSeq 2500 System (Illumina, USA) with 100 nucleotide paired-end reads, per the standard manufacturer’s protocol. The RNA-Seq reads were aligned to human reference genome (hg38) using Tophat (version 2.0.10) with default parameters. Read counts were scaled to reads per kilo-base of exon model per million mapped reads (RPKM).