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Knockout of ?-calcitonin gene-related peptide attenuates cholestatic liver injury by differentially regulating cellular senescence of hepatic stellate cells and cholangiocytes.

ABSTRACT: ?-Calcitonin gene-related peptide (?-CGRP) is a 37-amino acid neuropeptide involved in several pathophysiological processes. ?-CGRP is involved in the regulation of cholangiocyte proliferation during cholestasis. In this study, we aimed to evaluate if ?-CGRP regulates bile duct ligation (BDL)-induced liver fibrosis by using a ?-CGRP knockout (?-CGRP-/-) mouse model. ?-CGRP-/- and wild-type (WT) mice were subjected to sham surgery or BDL for 7 days. Then, liver fibrosis and cellular senescence as well as the expression of kinase such as p38 and C-Jun N-terminal protein kinase (JNK) in mitogen-activated protein kinases (MAPK) signaling pathway were evaluated in total liver, together with measurement of cellular senescence in cholangiocytes or hepatic stellate cells (HSCs). There was enhanced hepatic expression of Calca (coding ?-CGRP) and the CGRP receptor components (CRLR, RAMP-1 and RCP) in BDL and in both WT ?-CGRP-/- and BDL ?-CGRP-/- mice, respectively. Moreover, there was increased CGRP serum levels and hepatic mRNA expression of CALCA and CGRP receptor components in late-stage PSC samples compared to healthy control samples. Depletion of ?-CGRP reduced liver injury and fibrosis in BDL mice that was associated with enhanced cellular senescence of hepatic stellate cells and reduced senescence of cholangiocytes as well as decreased activation of p38 and JNK MAPK signaling pathway. Cholangiocyte supernatant from BDL ?-CGRP-/- mice inhibited the activation and increased cellular senescence of cultured human HSCs (HHSCs) compared to HHSCs stimulated with BDL cholangiocyte supernatant. Taken together, endogenous ?-CGRP promoted BDL-induced cholestatic liver fibrosis through differential changes in senescence of HSCs and cholangiocytes and activation of p38 and JNK signaling. Modulation of ?-CGRP/CGRP receptor signaling may be key for the management of biliary senescence and liver fibrosis in cholangiopathies.

SUBMITTER: Wan Y

PROVIDER: S-EPMC6570540 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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Knockout of α-calcitonin gene-related peptide attenuates cholestatic liver injury by differentially regulating cellular senescence of hepatic stellate cells and cholangiocytes.

Wan Ying Y Ceci Ludovica L Wu Nan N Zhou Tianhao T Chen Lixian L Venter Julie J Francis Heather H Bernuzzi Francesca F Invernizzi Pietro P Kyritsi Konstantina K Baker Paul P Huang Qiaobing Q Wu Chaodong C Sybenga Amelia A Alpini Gianfranco G Meng Fanyin F Glaser Shannon S

Laboratory investigation; a journal of technical methods and pathology 20190130 6

α-Calcitonin gene-related peptide (α-CGRP) is a 37-amino acid neuropeptide involved in several pathophysiological processes. α-CGRP is involved in the regulation of cholangiocyte proliferation during cholestasis. In this study, we aimed to evaluate if α-CGRP regulates bile duct ligation (BDL)-induced liver fibrosis by using a α-CGRP knockout (α-CGRP<sup>-/-</sup>) mouse model. α-CGRP<sup>-/-</sup> and wild-type (WT) mice were subjected to sham surgery or BDL for 7 days. Then, liver fibrosis and ...[more]

PMID: 30700848

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Project description:The pathogenesis of cirrhosis, a disabling outcome of defective liver repair, involves deregulated accumulation of myofibroblasts derived from quiescent hepatic stellate cells (HSCs), but the mechanisms that control transdifferentiation of HSCs are poorly understood. We investigated whether the Hedgehog (Hh) pathway controls the fate of HSCs by regulating metabolism.Microarray, quantitative polymerase chain reaction, and immunoblot analyses were used to identify metabolic genes that were differentially expressed in quiescent vs myofibroblast HSCs. Glycolysis and lactate production were disrupted in HSCs to determine if metabolism influenced transdifferentiation. Hh signaling and hypoxia-inducible factor 1? (HIF1?) activity were altered to identify factors that alter glycolytic activity. Changes in expression of genes that regulate glycolysis were quantified and localized in biopsy samples from patients with cirrhosis and liver samples from mice following administration of CCl(4) or bile duct ligation. Mice were given systemic inhibitors of Hh to determine if they affect glycolytic activity of the hepatic stroma; Hh signaling was also conditionally disrupted in myofibroblasts to determine the effects of glycolytic activity.Transdifferentiation of cultured, quiescent HSCs into myofibroblasts induced glycolysis and caused lactate accumulation. Increased expression of genes that regulate glycolysis required Hh signaling and involved induction of HIF1?. Inhibitors of Hh signaling, HIF1?, glycolysis, or lactate accumulation converted myofibroblasts to quiescent HSCs. In diseased livers of animals and patients, numbers of glycolytic stromal cells were associated with the severity of fibrosis. Conditional disruption of Hh signaling in myofibroblasts reduced numbers of glycolytic myofibroblasts and liver fibrosis in mice; similar effects were observed following administration of pharmacologic inhibitors of Hh.Hedgehog signaling controls the fate of HSCs by regulating metabolism. These findings might be applied to diagnosis and treatment of patients with cirrhosis.

Project description: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 H19maternalΔExon1/+ (H19KO) mice were subjected to BDL. Mdr2-/- H19maternalΔExon1/+ (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.

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Dataset Information

Knockout of ?-calcitonin gene-related peptide attenuates cholestatic liver injury by differentially regulating cellular senescence of hepatic stellate cells and cholangiocytes.

Publications

Knockout of α-calcitonin gene-related peptide attenuates cholestatic liver injury by differentially regulating cellular senescence of hepatic stellate cells and cholangiocytes.

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