Integrative miRNA and Gene Expression Profiling Analysis of Human Quiescent Hepatic Stellate Cells

Abstract

Unveiling the regulatory pathways maintaining hepatic stellate cells (HSC) in a quiescent (q) phenotype is essential to develop new therapeutic strategies to treat fibrogenic diseases. To uncover the miRNA-mRNA regulatory interactions in qHSCs, HSCs were FACS-sorted from healthy livers and activated HSCs (aHSCs) were generated in vitro. MiRNA Taqman array analysis showed HSCs expressed a low number of miRNAs (n = 259), from which 47 were down-regulated and 212 up-regulated upon activation. Computational integration of miRNA and gene expression profiles revealed that 66% of qHSC-associated miRNAs correlated with more than 6 altered target mRNAs (17,28 ± 10,7 targets/miRNA) whereas aHSC-associated miRNAs had an average of 1,49 targeted genes. Interestingly, interaction networks generated by miRNA-targeted genes in qHSCs were associated with key HSC activation processes. Next, selected miRNAs were validated in healthy and cirrhotic human livers and miR-192 was chosen for functional analysis. Down-regulation of miR-192 in HSCs was found to be an early event during fibrosis progression in mouse models of liver injury. Moreover, mimic assays for miR-192 in HSCs revealed its role in HSC activation, proliferation and migration. Together, these results uncover the importance of miRNAs in the maintenance of the qHSC phenotype and form the basis for understanding the regulatory networks in HSCs.

MicroRNA‐21 and Dicer are dispensable for hepatic stellate cell activation and the development of liver fibrosis

“…Currently, there are no approved antifibrotic drugs for the treatment of liver fibrosis. Recent studies on lung, kidney, heart, and liver fibrosis have reported that blocking miR-21 exerts antifibrogenic effects (12)(13)(14)(22)(23)(24)(25) and that miR-21 may therefore represent a potential therapeutic target. However, studies using both genetic knockout as well as pharmacologic approaches have refuted some of these findings, (15,45,46) thus rendering the contribution of miR-21 to fibrosis and its potential use as a therapeutic target controversial.…”

“…(18)(19)(20) In the liver, miR-21 is believed to regulate a wide range of injury responses, including hepatocyte proliferation, (21) biliary hyperplasia, (22) carcinogenesis, (23) and liver fibrosis. (22)(23)(24)(25) Here, we identified miR-21 as the microRNA with the highest induction in HSCs in multiple models of HSC activation. However, two diferent lines of miR-21 knockout mice as well as pharmacologic suppression of miR-21 expression did not reveal a role for this microRNA in HSC activation or liver fibrosis.…”

Integrative microRNA profiling in alcoholic hepatitis reveals a role for microRNA-182 in liver injury and inflammation

“…Both paired miRNA and mRNA expression profiles were used for the integrative analysis by MiRComb package, as previously described 18. Functional analysis of significant dysregulated gene targets was performed with Ingenuity Pathway Analysis (Qiagen; Red Wood, California, USA).…”

Hepatic stellate cells as key target in liver fibrosis

“…High-throughput miRNA profiling and other technologies have identified pro-fibrogenic miRNAs over-expressed in activated HSCs, including miR-9a-5p, miR-17-5p, miR-21, miR-27, miR-31, miR-33a, miR-34a/c, miR-125, miR-126, miR-130a/b, miR-181b, miR-214-5p, miR-195, miR-199a/b, miR-221, and miR-222, each of which induces proliferation, collagen secretion, and/or migration via a variety of pathways, and anti-fibrotic miRNAs, including miR-16, miR-19b, miR-29, miR-30, miR-101, miR-122, miR-133a, miR-144, miR-146a, miR-150, miR-155, miR-192, miR-195, miR-335, miR-454, and miR-483, although direction of change could depend on biological and/or experimental contexts [267–269]. miR-378 was recently shown to limit HSC activation by suppressing Gli3 [270].…”