Fanyin Meng Ph.D.

Kennedy, L., L. Hargrove, J. Demieville, A. Karstens, H. Jones, S. DeMorrow, F. Meng, P. Invernizzi, F. Bernuzzi, G. Alpini, S. Smith, A. Akers, V. Meadows and H. Francis (2018). “Blocking H1/H2 histamine receptors inhibits damage/fibrosis in Mdr2(-/-) mice and human cholangiocarcinoma tumorigenesis.” Hepatology. Mar 30. [Epub ahead of print].

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BACKGROUND: Primary Sclerosing Cholangitis (PSC) patients are at risk of developing cholangiocarcinoma (CCA). We have shown that: (i) histamine (HA) increases biliary hyperplasia via H1/H2 histamine receptors (HRs) and (ii) HA levels increase and mast cells (MCs) infiltrate during PSC and CCA. We aimed to examine the effects of chronic treatment with H1/H2HR antagonists on PSC and CCA. METHODS: Wild-type and Mdr2(-/-) mice were treated by osmotic minipumps with saline, mepyramine or ranitidine (10mg/kg BW/day) or a combination of mepyramine/ranitidine for 4 wks. Liver damage was assessed by H&E. We evaluated (i) H1/H2 HR expression; (ii) MC presence; (iii) l-histidine decarboxylase (HDC)/HA axis; (iv) cholangiocyte proliferation/bile duct mass (v) fibrosis/hepatic stellate cell (HSC) activation. Nu/nu mice were implanted with Mz-ChA-1 cells into the hind flanks and treated with saline, mepyramine or ranitidine. Tumor growth was measured and we evaluated: (i) H1/H2HR expression; (ii) proliferation; (iii) MC activation; (iv) angiogenesis and (v) epithelial-mesenchymal transition (EMT). In vitro, human hepatic stellate cells were evaluated for H1HR and H2HR expression. Cultured cholangiocytes and CCA lines were treated with saline, mepyramine or ranitidine (25 muM) before evaluating proliferation, angiogenesis, EMT, and potential signaling mechanisms. RESULTS: H1/H2HR and MC presence increased in human PSC and CCA. In H1/H2HR antagonist (alone or in combination)-treated Mdr2(-/-) mice, liver and biliary damage and fibrosis decreased compared to saline treatment. H1/H2HR antagonists decreased tumor growth, serum HA, angiogenesis and EMT. In vitro, H1/H2HR blockers reduced biliary proliferation, and CCA cells had decreased proliferation, angiogenesis, EMT and migration. CONCLUSION: Inhibition of H1/H2HR reverses PSC-associated damage and decreases CCA growth, angiogenesis and EMT. Since PSC patients are at risk of developing CCA, using HR blockers may be therapeutic for these diseases. This article is protected by copyright. All rights reserved.

Kennedy, L., L. Hargrove, J. Demieville, J. M. Bailey, W. Dar, K. Polireddy, Q. Chen, M. I. Nevah Rubin, A. Sybenga, S. DeMorrow, F. Meng, L. Stockton, G. Alpini and H. Francis (2018). “Knockout of l-Histidine Decarboxylase Prevents Cholangiocyte Damage and Hepatic Fibrosis in Mice Subjected to High-Fat Diet Feeding via Disrupted Histamine/Leptin Signaling.” Am J Pathol 188(3): 600-615.

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Feeding a high-fat diet (HFD) coupled with sugar, mimicking a Western diet, causes fatty liver disease in mice. Histamine induces biliary proliferation and fibrosis and regulates leptin signaling. Wild-type (WT) and l-histidine decarboxylase (Hdc(-/-)) mice were fed a control diet or an HFD coupled with a high fructose corn syrup equivalent. Hematoxylin and eosin and Oil Red O staining were performed to determine steatosis. Biliary mass and cholangiocyte proliferation were evaluated by immunohistochemistry. Senescence and fibrosis were measured by quantitative PCR and immunohistochemistry. Hepatic stellate cell activation was detected by immunofluorescence. Histamine and leptin levels were measured by enzyme immunoassay. Leptin receptor (Ob-R) was evaluated by quantitative PCR. The HDC/histamine/histamine receptor axis, ductular reaction, and biliary senescence were evaluated in patients with nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, or end-stage liver disease. Hdc(-/-) HFD mice had increased steatosis compared with WT HFD mice. WT HFD mice had increased biliary mass, biliary proliferation, senescence, fibrosis, and hepatic stellate cell activation, which were reduced in Hdc(-/-) HFD mice. In Hdc(-/-) HFD mice, serum leptin levels increased, whereas biliary Ob-R expression decreased. Nonalcoholic steatohepatitis patients had increased HDC/histamine/histamine receptor signaling. Hdc(-/-) HFD mice are susceptible to obesity via dysregulated leptin/Ob-R signaling, whereas the lack of HDC protects from HFD-induced fibrosis and cholangiocyte damage. HDC/histamine/leptin signaling may be important in managing obesity-induced biliary damage.

Wu, N., F. Meng, T. Zhou, Y. Han, L. Kennedy, J. Venter, H. Francis, S. DeMorrow, P. Onori, P. Invernizzi, F. Bernuzzi, R. Mancinelli, E. Gaudio, A. Franchitto, S. Glaser and G. Alpini (2017). “Prolonged darkness reduces liver fibrosis in a mouse model of primary sclerosing cholangitis by mir-200b down-regulation.” Faseb j 31(10): 4305-4324.

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Melatonin therapy or prolonged exposure to complete darkness reduces biliary hyperplasia and liver fibrosis in bile-duct-ligated (BDL) rats; however, no information exists in primary sclerosing cholangitis (PSC). Thus, we aimed to determine the therapeutic effects of prolonged dark therapy or melatonin administration on hepatic fibrosis in the multidrug resistance gene 2-knockout (Mdr2-/-) mouse model of PSC. Melatonin levels, biliary mass, liver fibrosis, angiogenesis and miR-200b expression were evaluated in wild-type and Mdr2-/- mice exposed to darkness or melatonin treatment or in male patients with PSC and healthy controls. Mdr2-/- mice were also treated with miR-200b inhibitor or control before evaluating biliary mass, liver fibrosis, and angiogenesis. After overexpression of arylalkylamine N-acetyltransferase (AANAT; the enzyme regulating melatonin synthesis) or inhibition of miR-200b in cholangiocytes and hepatic stellate cells in vitro, we evaluated angiogenesis and fibrosis gene expression. After exposure to darkness or administration of melatonin, Mdr2-/- mice show elevated serum melatonin levels and inhibition of biliary mass, along with reduction of liver fibrosis and angiogenesis. MicroRNA PCR analysis demonstrated that miR-200b expression increased in Mdr2-/- mice and patients with PSC compared with controls and decreased in Mdr2-/- mice subjected to dark exposure or melatonin treatment. Inhibition of miR-200b in Mdr2-/- ablates biliary proliferation, liver fibrosis, and angiogenesis. In vitro, overexpression of AANAT or inhibition of miR-200b in cholangiocytes and hepatic stellate cells decreased the expression of miR-200b, angiogenesis, and fibrosis genes. Dark therapy or targeting melatonin/miR-200b axis may be important in the management of biliary damage and liver fibrosis in cholangiopathies including PSC.-Wu, N., Meng, F., Zhou, T., Han, Y., Kennedy, L., Venter, J., Francis, H., DeMorrow, S., Onori, P., Invernizzi, P., Bernuzzi, F., Mancinelli, R., Gaudio, E., Franchitto, A., Glaser, S., Alpini G. Prolonged darkness reduces liver fibrosis in a mouse model of primary sclerosing cholangitis by miR-200b down-regulation.

Wu, N., Q. Nguyen, Y. Wan, T. Zhou, J. Venter, G. A. Frampton, S. DeMorrow, D. Pan, F. Meng, S. Glaser, G. Alpini and H. Bai (2017). “The hippo signaling functions through the notch signaling to regulate intrahepatic bile duct development in mammals.” Lab Invest 97(7): 843-853.

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The Hippo signaling pathway and the Notch signaling pathway are evolutionary conserved signaling cascades that have important roles in embryonic development of many organs. In murine liver, disruption of either pathway impairs intrahepatic bile duct development. Recent studies suggested that the Notch signaling receptor Notch2 is a direct transcriptional target of the Hippo signaling pathway effector YAP, and the Notch signaling is a major mediator of the Hippo signaling in maintaining biliary cell characteristics in adult mice. However, it remains to be determined whether the Hippo signaling pathway functions through the Notch signaling in intrahepatic bile duct development. We found that loss of the Hippo signaling pathway tumor suppressor Nf2 resulted in increased expression levels of the Notch signaling pathway receptor Notch2 in cholangiocytes but not in hepatocytes. When knocking down Notch2 on the background of Nf2 deficiency in mouse livers, the excessive bile duct development induced by Nf2 deficiency was suppressed by heterozygous and homozygous deletion of Notch2 in a dose-dependent manner. These results implicated that Notch signaling is one of the downstream effectors of the Hippo signaling pathway in regulating intrahepatic bile duct development.

Wu, N., F. Meng, T. Zhou, Y. Han, L. Kennedy, J. Venter, H. Francis, S. DeMorrow, P. Onori, P. Invernizzi, F. Bernuzzi, R. Mancinelli, E. Gaudio, A. Franchitto, S. Glaser and G. Alpini (2017). “Prolonged darkness reduces liver fibrosis in a mouse model of primary sclerosing cholangitis by mir-200b down-regulation.” Faseb j: 2017 Jun [Epub ahead of print].

Full text of this article.

Melatonin therapy or prolonged exposure to complete darkness reduces biliary hyperplasia and liver fibrosis in bile-duct-ligated (BDL) rats; however, no information exists in primary sclerosing cholangitis (PSC). Thus, we aimed to determine the therapeutic effects of prolonged dark therapy or melatonin administration on hepatic fibrosis in the Mdr2-/- mouse model of PSC. Melatonin levels, biliary mass, liver fibrosis, angiogenesis and miR-200b expression were evaluated in wild-type and Mdr2-/- mice exposed to darkness or melatonin treatment or in male PSC patient samples and healthy controls. Mdr2-/- mice were also treated with miR-200b inhibitor or control before evaluating biliary mass, liver fibrosis, and angiogenesis. After overexpression of arylalkylamine N-acetyltransferase (AANAT; the enzyme regulating melatonin synthesis) or inhibition of miR-200b in cholangiocytes and hepatic stellate cells in vitro, we evaluated angiogenesis and fibrosis gene expression. After exposure to darkness or administration of melatonin, Mdr2-/- mice show elevated serum melatonin levels and inhibition of biliary mass, along with reduction of liver fibrosis and angiogenesis. miRNA PCR analysis demonstrated that miR-200b expression increased in Mdr2-/- mice and PSC patient samples compared with controls and decreased in Mdr2-/- mice subjected to dark exposure or melatonin treatment. Inhibition of miR-200b in Mdr2-/- ablates biliary proliferation, liver fibrosis, and angiogenesis. In vitro, overexpression of AANAT or inhibition of miR-200b in cholangiocytes and hepatic stellate cells decreased the expression of miR-200b, angiogenesis, and fibrosis genes. Dark therapy or targeting melatonin/miR-200b axis may be important in the management of biliary damage and liver fibrosis in cholangiopathies including PSC.-Wu, N., Meng, F., Zhou, T., Han, Y., Kennedy, L., Venter, J., Francis, H., DeMorrow, S., Onori, P., Invernizzi, P., Bernuzzi, F., Mancinelli, R., Gaudio, E., Franchitto, A., Glaser, S., Alpini G. Prolonged darkness reduces liver fibrosis in a mouse model of primary sclerosing cholangitis by miR-200b down-regulation.