Cholangiocyte‐Derived Exosomal Long Noncoding RNA H19 Promotes Hepatic Stellate Cell Activation and Cholestatic Liver Fibrosis

Abstract

Activation of hepatic stellate cells (HSCs) represents the primary driving force to promote the progression of chronic cholestatic liver diseases. We previously reported that cholangiocyte-derived exosomal long noncoding RNA-H19 (lncRNA-H19) plays a critical role in promoting cholestatic liver injury. However, it remains unclear whether cholangiocyte-derived lncRNA-H19 regulates HSC activation, which is the major focus of this study. Both bile duct ligation (BDL) and Mdr2 knockout (Mdr2 -/-) mouse models were used. Wild-type and H19 maternalΔExon1/+ (H19KO) mice were subjected to BDL. Mdr2 -/-H19 maternalΔExon1/+ (DKO) mice were generated. Exosomes isolated from cultured mouse and human cholangiocytes or mouse serum were used for in vivo transplantation and in vitro studies. Fluorescence-labeled exosomes and flow cytometry were used to monitor exosome uptake by hepatic cells. Collagen gel contraction and bromodeoxyuridine assays were used to determine the effect of exosomal-H19 on HSC activation and proliferation. Mouse and human primary sclerosing cholangitis (PSC)/primary biliary cholangitis (PBC) liver samples were analyzed by real-time PCR, western blot analysis, histology, and immunohistochemistry. The results demonstrated that hepatic H19 level was closely correlated with the severity of liver fibrosis in both mouse models and human patients with PSC and PBC. H19 deficiency significantly protected mice from liver fibrosis in BDL and Mdr2 -/mice. Transplanted cholangiocyte-derived H19-enriched exosomes were rapidly and preferentially taken up by HSCs and HSC-derived fibroblasts, and promoted liver fibrosis in BDL-H19KO mice and DKO mice. H19-enriched exosomes enhanced transdifferentiation of cultured mouse primary HSCs and promoted proliferation and matrix formation in HSC-derived fibroblasts. Conclusion: Cholangiocyte-derived exosomal H19 plays a critical role in the progression of cholestatic liver fibrosis by promoting HSC differentiation and activation and represents a potential diagnostic biomarker and therapeutic target for cholangiopathies. (Hepatology 2019;70:1317-1335).

Melatonin and circadian rhythms in liver diseases: Functional roles and potential therapies

“…Lipotoxic hepatocyte‐derived EVs induced inflammatory responses such as IL‐1β and IL‐6 production in macrophages by delivering cargo TRAIL . Another study has demonstrated that cholangiocytes secrete EVs that contain elevated levels of lncRNA H19 during cholestatic liver injury, and these H19‐enriched EVs activates HSCs leading to liver fibrosis in cholangiopathies …”

“…104 Another study has demonstrated that cholangiocytes secrete EVs that contain elevated levels of lncRNA H19 during cholestatic liver injury, and these H19-enriched EVs activates HSCs leading to liver fibrosis in cholangiopathies. 105 EVs mediate inflammatory or fibrogenic responses in hepatic cells by delivering cargo mediators, which means that EVs could be used as therapeutic tools or drug carriers to regulate functions of cells by delivering mediators to maintain homeostasis during liver diseases. 106 For example, EVs secreted from liver stem cells contained elevated levels of miRNA let-7a, and injection of stem cell-derived EVs ameliorated ductular reaction and liver fibrosis in Mdr2 −/− mice by delivering cargo let-7a.…”

Long noncoding RNA XIST enhances ethanol‐induced hepatic stellate cells autophagy and activation via miR‐29b/HMGB1 axis

“…Liver fibrosis is a frequent consequence of liver injury and can progress to cirrhosis and even hepatocarcinoma. Activation of hepatic stellate cells (HSCs)—transdifferentiation of quiescent, vitamin‐A‐storing cells into proliferative, fibrogenic myofibroblasts—is a prominent driver of liver fibrogenesis Thus, suppression of activated HSCs is of great importance for preventing liver fibrosis.…”

Silencing lncRNA Lfar1 alleviates the classical activation and pyoptosis of macrophage in hepatic fibrosis

“…It has been reported that up to 90% of eukaryotic genomes are transcribed, while the majority of transcripts are lncRNAs, which are a group of transcripts longer than 200 nucleotides but do not encode protein 12 . Despite their poor conservation and low levels of expression compared with protein-coding genes, more and more lncRNAs are reported to get involved in a variety of physiological and pathological processes, such as hepatic fibrosis 19,[24][25][26][27][28] . For instance, lncRNA H19 aggravated cholestatic liver fibrosis either by promoting HSCs activation or by preventing ZEB1-mediated inhibition of epithelial cell adhesion molecule 25,29 .…”

“…Despite their poor conservation and low levels of expression compared with protein-coding genes, more and more lncRNAs are reported to get involved in a variety of physiological and pathological processes, such as hepatic fibrosis 19,[24][25][26][27][28] . For instance, lncRNA H19 aggravated cholestatic liver fibrosis either by promoting HSCs activation or by preventing ZEB1-mediated inhibition of epithelial cell adhesion molecule 25,29 . Yu et al 27 has demonstrated that lncRNA SNHG7 reduced miR-378a-3p and attenuated its control on DVL2, leading to aberrant Wnt/β-catenin activity that contributes to liver fibrotic progression.…”