Browsing by Author "Wu, Chaodong"

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    Amelioration of Ductular Reaction by Stem Cell Derived Extracellular Vesicles in MDR2 Knockout Mice via Lethal-7 microRNA
    (Wiley, 2019-02-05) McDaniel, Kelly; Wu, Nan; Zhou, Tianhao; Huang, Li; Sato, Keisaku; Venter, Julie; Ceci, Ludovica; Chen, Demeng; Ramos‐Lorenzo, Sugeily; Invernizzi, Pietro; Bernuzzi, Francesca; Wu, Chaodong; Francis, Heather; Glaser, Shannon; Alpini, Gianfranco; Meng, Fanyin; Medicine, School of Medicine
    Cholangiopathies are diseases that affect cholangiocytes, the cells lining the biliary tract. Liver stem cells (LSCs) are able to differentiate into all cells of the liver and possibly influence the surrounding liver tissue by secretion of signaling molecules. One way in which cells can interact is through secretion of extracellular vesicles (EVs), which are small membrane-bound vesicles that contain proteins, microRNAs (miRNAs), and cytokines. We evaluated the contents of liver stem cell–derived EVs (LSCEVs), compared their miRNA contents to those of EVs isolated from hepatocytes, and evaluated the downstream targets of these miRNAs. We finally evaluated the crosstalk among LSCs, cholangiocytes, and human hepatic stellate cells (HSCs). We showed that LSCEVs were able to reduce ductular reaction and biliary fibrosis in multidrug resistance protein 2 (MDR2)−/− mice. Additionally, we showed that cholangiocyte growth was reduced and HSCs were deactivated in LSCEV-treated mice. Evaluation of LSCEV contents compared with EVs derived from hepatocytes showed a large increase in the miRNA, lethal-7 (let-7). Further evaluation of let-7 in MDR2−/− mice and human primary sclerosing cholangitis samples showed reduced levels of let-7 compared with controls. In liver tissues and isolated cholangiocytes, downstream targets of let-7 (identified by ingenuity pathway analysis), Lin28a (Lin28 homolog A), Lin28b (Lin28 homolog B), IL-13 (interleukin 13), NR1H4 (nuclear receptor subfamily 1 group H member 4) and NF-κB (nuclear factor kappa B), are elevated in MDR2−/− mice, but treatment with LSCEVs reduced levels of these mediators of ductular reaction and biliary fibrosis through the inhibition of NF-κB and IL-13 signaling pathways. Evaluation of crosstalk using cholangiocyte supernatants from LSCEV-treated cells on cultured HSCs showed that HSCs had reduced levels of fibrosis and increased senescence. Conclusion: Our studies indicate that LSCEVs could be a possible treatment for cholangiopathies or could be used for target validation for future therapies.
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    The Apelin–Apelin Receptor Axis Triggers Cholangiocyte Proliferation and Liver Fibrosis During Mouse Models of Cholestasis
    (Wiley, 2021-06) Chen, Lixian; Zhou, Tianhao; White, Tori; O'Brien, April; Chakraborty, Sanjukta; Liangpunsakul, Suthat; Yang, Zhihong; Kennedy, Lindsey; Saxena, Romil; Wu, Chaodong; Meng, Fanyin; Huang, Qiaobing; Francis, Heather; Alpini, Gianfranco; Glaser, Shannon; Medicine, School of Medicine
    Background and Aims Apelin (APLN) is the endogenous ligand of its G protein–coupled receptor, apelin receptor (APJ). APLN serum levels are increased in human liver diseases. We evaluated whether the APLN–APJ axis regulates ductular reaction and liver fibrosis during cholestasis. Approach and Results We measured the expression of APLN and APJ and serum APLN levels in human primary sclerosing cholangitis (PSC) samples. Following bile duct ligation (BDL) or sham surgery, male wild-type (WT) mice were treated with ML221 (APJ antagonist) or saline for 1 week. WT and APLN−/− mice underwent BDL or sham surgery for 1 week. Multidrug resistance gene 2 knockout (Mdr2−/−) mice were treated with ML221 for 1 week. APLN levels were measured in serum and cholangiocyte supernatants, and cholangiocyte proliferation/senescence and liver inflammation, fibrosis, and angiogenesis were measured in liver tissues. The regulatory mechanisms of APLN–APJ in (1) biliary damage and liver fibrosis were examined in human intrahepatic biliary epithelial cells (HIBEpiCs) treated with APLN and (2) hepatic stellate cell (HSC) activation in APLN-treated human HSC lines (HHSteCs). APLN serum levels and biliary expression of APLN and APJ increased in PSC samples. APLN levels were higher in serum and cholangiocyte supernatants from BDL and Mdr2−/− mice. ML221 treatment or APLN−/− reduced BDL-induced and Mdr2−/−-induced cholangiocyte proliferation/senescence, liver inflammation, fibrosis, and angiogenesis. In vitro, APLN induced HIBEpiC proliferation, increased nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) expression, reactive oxygen species (ROS) generation, and extracellular signal–regulated kinase (ERK) phosphorylation. Pretreatment of HIBEpiCs with ML221, diphenyleneiodonium chloride (Nox4 inhibitor), N-acetyl-cysteine (NAC, ROS inhibitor), or PD98059 (ERK inhibitor) reduced APLN-induced cholangiocyte proliferation. Activation of HHSteCs was induced by APLN but reduced by NAC. Conclusions The APLN–APJ axis induces cholangiocyte proliferation through Nox4/ROS/ERK-dependent signaling and HSC activation through intracellular ROS. Modulation of the APLN–APJ axis may be important for managing cholangiopathies.
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    Downregulation of p16 Decreases Biliary Damage and Liver Fibrosis in the Mdr2 / Mouse Model of Primary Sclerosing Cholangitis
    (Cognizant Communication Corporation, 2020-11) Kyritsi, Konstantina; Francis, Heather; Zhou, Tianhao; Ceci, Ludovica; Wu, Nan; Yang, Zhihong; Meng, Fanyin; Chen, Lixian; Baiocchi, Leonardo; Kundu, Debjyoti; Kennedy, Lindsey; Liangpunsakul, Suthat; Wu, Chaodong; Glaser, Shannon; Alpini, Gianfranco; Medicine, School of Medicine
    Biliary senescence and hepatic fibrosis are hallmarks of cholangiopathies including primary sclerosing cholangitis (PSC). Senescent cholangiocytes display senescence-associated secretory phenotypes [SASPs, e.g., transforming growth factor-1 (TGF-1)] that further increase biliary senescence (by an autocrine loop) and trigger liver fibrosis by paracrine mechanisms. The aim of this study was to determine the effect of p16 inhibition and role of the TGF-1/microRNA (miR)-34a/sirtuin 1 (SIRT1) axis in biliary damage and liver fibrosis in the Mdr2/ mouse model of PSC. We treated (i) in vivo male wild-type (WT) and Mdr2/ mice with p16 Vivo-Morpholino or controls before measuring biliary mass [intrahepatic bile duct mass (IBDM)] and senescence, biliary SASP levels, and liver fibrosis, and (ii) in vitro intrahepatic murine cholangiocyte lines (IMCLs) with small interfering RNA against p16 before measuring the mRNA expression of proliferation, senescence, and fibrosis markers. p16 and miR-34a increased but SIRT1 decreased in Mdr2/ mice and PSC human liver samples compared to controls. p16 immunoreactivity and biliary senescence and SASP levels increased in Mdr2/ mice but decreased in Mdr2/ mice treated with p16 Vivo-Morpholino. The increase in IBDM and hepatic fibrosis (observed in Mdr2/ mice) returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. TGF-1 immunoreactivity and biliary SASPs levels were higher in Mdr2/ compared to those of WT mice but returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. The expression of fibrosis/senescence markers decreased in cholangiocytes from Mdr2/ mice treated with p16 Vivo-Morpholino (compared to Mdr2/ mice) and in IMCLs (after p16 silencing) compared to controls. Modulation of the TGF-1/miR-34a/SIRT1 axis may be important in the management of PSC phenotypes.
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    Functional Role of the Secretin/Secretin Receptor Signaling During Cholestatic Liver Injury
    (AASLD, 2020-12) Wu, Nan; Baiocchi, Leonardo; Zhou, Tianhao; Kennedy, Lindsey; Ceci, Ludovica; Meng, Fanyin; Sato, Keisaku; Wu, Chaodong; Ekser, Burcin; Kyritsi, Konstantina; Kundu, Debjyoti; Chen, Lixian; Meadows, Vik; Franchitto, Antonio; Alvaro, Domenico; Onori, Paolo; Gaudio, Eugenio; Lenci, Ilaria; Francis, Heather; Glaser, Shannon; Alpini, Gianfranco; Medicine, School of Medicine
    Liver diseases are a major health concern and affect a large proportion of people worldwide. There are over 100 types of liver disorders, including cirrhosis, cholangiocarcinoma (CCA), hepatocellular carcinoma, and hepatitis. Despite the relevant number of people who are affected by liver diseases, and the increased awareness with regard to these disorders, the number of deaths corresponding to liver injury is expected to increase in the foreseeable future. One of the possible reasons for this is that a complete comprehension of the mechanisms of hepatic damage involving specific liver anatomical districts is lacking, and, as a consequence, current treatments available are suboptimal. A major burden in the clinical setting are chronic cholestatic liver diseases (e.g., primary biliary cholangitis [PBC], primary sclerosing cholangitis [PSC], biliary atresia), which target the biliary epithelium and are characterized by cholestasis.(1, 2) Because the secretin (Sct)/secretin receptor (SR) axis (expressed only by cholangiocytes in the liver)(3, 4) is the major regulator of ductal bile secretion,(5, 6) it is intuitive that this axis plays a key role in the maintenance of biliary homeostasis during the progression of cholangiopathies. For instance, PBC is characterized by reduced bicarbonate secretion, a phenomenon possibly impeding the formation of an HCO3 canalicular film (“bicarbonate umbrella”) on bile ducts, which has protective properties against highly concentrated bile acids (BAs).(1, 7, 8) In this review, we examined the molecular mechanisms by which the Sct/SR axis regulates biliary function and the homeostasis of the biliary epithelium in normal and pathophysiological conditions.
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    Inhibition of Secretin/Secretin Receptor Axis Ameliorates NAFLD Phenotypes
    (Wiley, 2021-10) Chen, Lixian; Wu, Nan; Kennedy, Lindsey; Francis, Heather; Ceci, Ludovica; Zhou, Tianhao; Samala, Niharika; Kyritsi, Konstantina; Wu, Chaodong; Sybenga, Amelia; Ekser, Burcin; Dar, Wasim; Atkins, Constance; Meadows, Vik; Glaser, Shannon; Alpini, Gianfranco; Surgery, School of Medicine
    Background & Aims Human non-alcoholic fatty liver disease (NAFLD) is characterized at early stages by hepatic steatosis, which may progress to nonalcoholic steatohepatitis (NASH) when the liver displays microvesicular steatosis, lobular inflammation, and pericellular fibrosis. The secretin (SCT)/secretin receptor (SCTR) axis promotes biliary senescence and liver fibrosis in cholestatic models through downregulation of miR-125b signaling. We aim to evaluate the effect of disrupting biliary SCT/SCTR/miR-125b signaling on hepatic steatosis, biliary senescence and liver fibrosis in NAFLD/NASH. Approach & Results In vivo, 4 wk male WT, Sct-/- and Sctr-/- mice were fed a control diet (CD) or high-fat diet (HFD) for 16 wks. The expression of SCT/SCTR/miR-125b axis was measured in human NAFLD/NASH liver samples and HFD mouse livers by immunohistochemistry (IHC) and qPCR. Biliary/hepatocyte senescence, ductular reaction and liver angiogenesis were evaluated in mouse liver and human NAFLD/NASH liver samples. miR-125b target lipogenesis genes in hepatocytes were screened and validated by custom RT2 Profiler PCR array and luciferase assay. Biliary SCT/SCTR expression was increased in human NAFLD/NASH samples and in livers of HFD mice, whereas the expression of miR-125b was decreased. Biliary/hepatocyte senescence, ductular reaction, and liver angiogenesis were observed in human NAFLD/NASH samples as well as HFD mice, which were decreased in Sct-/- and Sctr-/- HFD mice. Elovl1 is a lipogenesis gene targeted by miR-125b, and its expression was also decreased in HFD mouse hepatocytes following Sct or Sctr knockout. Bile acid profile in fecal samples have the greatest changes between WT mice and Sct-/-/Sctr-/- mice. Conclusion The biliary SCT/SCTR/miR-125b axis promotes liver steatosis by upregulating lipid biosynthesis gene Elovl1. Targeting the biliary SCT/SCTR/miR-125b axis may be key for ameliorating phenotypes of human NAFLD/NASH.
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    Knockdown of vimentin reduces mesenchymal phenotype of cholangiocytes in the Mdr2-/- mouse model of primary sclerosing cholangitis (PSC)
    (Elsevier, 2019-10) Zhou, Tianhao; Kyritsi, Konstantina; Wu, Nan; Francis, Heather; Yang, Zhihong; Chen, Lixian; O'Brien, April; Kennedy, Lindsey; Ceci, Ludovica; Meadows, Vik; Kusumanchi, Praveen; Wu, Chaodong; Baiocchi, Leonardo; Skill, Nicholas J.; Saxena, Romil; Sybenga, Amelia; Xie, Linglin; Liangpunsakul, Suthat; Meng, Fanyin; Alpini, Gianfranco; Glaser, Shannon; Medicine, School of Medicine
    BACKGROUND: Cholangiocytes are the target cells of cholangiopathies including primary sclerosing cholangitis (PSC). Vimentin is an intermediate filament protein that has been found in various types of mesenchymal cells. The aim of this study is to evaluate the role of vimentin in the progression of biliary damage/liver fibrosis and whether there is a mesenchymal phenotype of cholangiocytes in the Mdr2-/- model of PSC. METHODS: In vivo studies were performed in 12 wk. Mdr2-/- male mice with or without vimentin Vivo-Morpholino treatment and their corresponding control groups. Liver specimens from human PSC patients, human intrahepatic biliary epithelial cells (HIBEpiC) and human hepatic stellate cell lines (HHSteCs) were used to measure changes in epithelial-to-mesenchymal transition (EMT). FINDINGS: There was increased mesenchymal phenotype of cholangiocytes in Mdr2-/- mice, which was reduced by treatment of vimentin Vivo-Morpholino. Concomitant with reduced vimentin expression, there was decreased liver damage, ductular reaction, biliary senescence, liver fibrosis and TGF-β1 secretion in Mdr2-/- mice treated with vimentin Vivo-Morpholino. Human PSC patients and derived cell lines had increased expression of vimentin and other mesenchymal markers compared to healthy controls and HIBEpiC, respectively. In vitro silencing of vimentin in HIBEpiC suppressed TGF-β1-induced EMT and fibrotic reaction. HHSteCs had decreased fibrotic reaction and increased cellular senescence after stimulation with cholangiocyte supernatant with reduced vimentin levels. INTERPRETATION: Our study demonstrated that knockdown of vimentin reduces mesenchymal phenotype of cholangiocytes, which leads to decreased biliary senescence and liver fibrosis. Inhibition of vimentin may be a key therapeutic target in the treatment of cholangiopathies including PSC. FUND: National Institutes of Health (NIH) awards, VA Merit awards.
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    Modulation of the Tryptophan Hydroxylase 1/Monoamine Oxidase-A/5-Hydroxytryptamine/5-Hydroxytryptamine Receptor 2A/2B/2C Axis Regulates Biliary Proliferation and Liver Fibrosis During Cholestasis
    (Wiley, 2020-03) Kyritsi, Konstantina; Chen, Lixian; O’Brien, April; Francis, Heather; Hein, Travis W.; Venter, Julie; Wu, Nan; Ceci, Ludovica; Zhou, Tianhao; Zawieja, David; Gashev, Anatoliy A.; Meng, Fanyin; Invernizzi, Pietro; Fabris, Luca; Wu, Chaodong; Skill, Nicholas J.; Saxena, Romil; Liangpunsakul, Suthat; Alpini, Gianfranco; Glaser, Shannon S.; Medicine, School of Medicine
    Background and aims: Serotonin (5HT) is a neuroendocrine hormone synthetized in the central nervous system (CNS) as well as enterochromaffin cells of the gastrointestinal tract. Tryptophan hydroxylase (TPH1) and monoamine oxidase (MAO-A) are the key enzymes for the synthesis and catabolism of 5HT, respectively. Previous studies demonstrated that 5-hydroxytryptamine receptor (5HTR)1A/1B receptor agonists inhibit biliary hyperplasia in bile-duct ligated (BDL) rats, whereas 5HTR2B receptor antagonists attenuate liver fibrosis (LF) in mice. Our aim was to evaluate the role of 5HTR2A/2B/2C agonists/antagonists in cholestatic models. Approach and results: While in vivo studies were performed in BDL rats and the multidrug resistance gene 2 knockout (Mdr2-/- ) mouse model of PSC, in vitro studies were performed in cell lines of cholangiocytes and hepatic stellate cells (HSCs). 5HTR2A/2B/2C and MAO-A/TPH1 are expressed in cholangiocytes and HSCs from BDL rats and Mdr2-/- - mice. Ductular reaction, LF, as well as the mRNA expression of proinflammatory genes increased in normal, BDL rats, and Mdr2-/- - mice following treatment 5HTR2A/2B/2C agonists, but decreased when BDL rats and Mdr2-/- mice were treated with 5HTR2A/2B/2C antagonists compared to BDL rats and Mdr2-/- mice, respectively. 5HT levels increase in Mdr2-/- mice and in PSC human patients compared to their controls and decrease in serum of Mdr2-/- mice treated with 5HTR2A/2B/2C antagonists compared to untreated Mdr2-/- mice. In vitro, cell lines of murine cholangiocytes and human HSCs express 5HTR2A/2B/2C and MAO-A/TPH1; treatment of these cell lines with 5HTR2A/2B/2C antagonists or TPH1 inhibitor decreased 5HT levels as well as expression of fibrosis and inflammation genes compared to controls. Conclusions: Modulation of the TPH1/MAO-A/5HT/5HTR2A/2B/2C axis may represent a therapeutic approach for management of cholangiopathies, including PSC.