Cholangiocytes are the target cells in cholestatic liver diseases such as primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC), which are characterized by the damage and proliferation of these cells. Cholangiocyte proliferation is critical for the maintenance of the biliary mass and secretory function during the pathogenesis of these devastating liver diseases. Proliferating cholangiocytes serve as a neuroendocrine compartment during the progression of liver diseases, and as such secrete a number of growth factors, and respond to hormones, neurotransmitters and neuropeptides contributing to the autocrine and paracrine pathways that modulate liver inflammation and fibrosis. The overall objective of this proposal is to determine the molecular mechanisms by which local (from cholangiocytes), paracrine (by administration of melatonin or anti-melatonin antibody) and central (from pineal gland) melatonin synthesis (regulated by the enzyme AANAT expressed in the liver mainly by cholangiocytes) participates in the homeostasis of the biliary mass during cholestasis and liver damage. We proposed the central hypothesis that local melatonin synthesis in cholangiocytes as well as central secretion of melatonin from the pineal gland (pineal gland/biliary axis) coordinately regulates biliary proliferation/damage during cholestasis. To test the central hypothesis, we have proposed two specific aims: (1) Evaluate the effects of the modulation of melatonin synthesis by pineal gland during cholestasis on cholangiocyte proliferation;and (2) Define the role of local melatonin synthesis in the regulation of the proliferation/damage of cholangiocytes to cholestasis. At the completion of this project, we expect to have determined the extent to which proliferation of cholangiocytes is regulated by central and local melatonin synthesis, and to have identified key signaling pathways by which melatonin regulates biliary proliferation/damage. The information gained from the successful completion of these studies are expected to provide important insights into the intracellular mechanisms regulating cholangiocyte proliferation, which will ultimately help in the identification of specific factors and pathways that can be targeted for the development of therapeutic interventions. Finally, results of these studies may impact the development of improved therapeutic strategies (targeting AANAT) for the treatment of chronic cholestatic liver diseases.

Public Health Relevance

The health relatedness of this grant proposal is that effective treatments are lacking for chronic cholestatic liver diseases, such as primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Chronic cholestatic liver diseases (cholangiopathies) cause proliferation/damage of bile ducts inside the liver. The rationale for our research is that the successful completion of the studies can ultimately be expected to provide a greater understanding of the progressive mechanisms of cholestatic liver diseases, and increase opportunities for the development of novel treatment paradigms for the management of chronic liver diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK062975-05A1
Application #
8236156
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Sherker, Averell H
Project Start
2002-12-01
Project End
2012-07-31
Budget Start
2011-09-20
Budget End
2012-07-31
Support Year
5
Fiscal Year
2011
Total Cost
$281,327
Indirect Cost
Name
Texas A&M University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
835607441
City
College Station
State
TX
Country
United States
Zip Code
77845
Kennedy, Indsey; Francis, Heather; Meng, Fanyin et al. (2017) Diagnostic and therapeutic potentials of microRNAs in cholangiopathies. Liver Res 1:34-41
Hall, Chad; Ehrlich, Laurent; Meng, Fanyin et al. (2017) Inhibition of microRNA-24 increases liver fibrosis by enhanced menin expression in Mdr2-/- mice. J Surg Res 217:160-169
Hall, Chad; Ehrlich, Laurent; Venter, Julie et al. (2017) Inhibition of the apelin/apelin receptor axis decreases cholangiocarcinoma growth. Cancer Lett 386:179-188
Wan, Ying; McDaniel, Kelly; Wu, Nan et al. (2017) Regulation of Cellular Senescence by miR-34a in Alcoholic Liver Injury. Am J Pathol 187:2788-2798
Ehrlich, Laurent; Hall, Chad; Meng, Fanyin et al. (2017) A Review of the Scaffold Protein Menin and its Role in Hepatobiliary Pathology. Gene Expr 17:251-263
Kyritsi, Konstantina; Meng, Fanyin; Zhou, Tianhao et al. (2017) Knockdown of Hepatic Gonadotropin-Releasing Hormone by Vivo-Morpholino Decreases Liver Fibrosis in Multidrug Resistance Gene 2 Knockout Mice by Down-Regulation of miR-200b. Am J Pathol 187:1551-1565
Ehrlich, Laurent; Hall, Chad; Venter, Julie et al. (2017) miR-24 Inhibition Increases Menin Expression and Decreases Cholangiocarcinoma Proliferation. Am J Pathol 187:570-580
Sato, Keisaku; Meng, Fanyin; Venter, Julie et al. (2017) The role of the secretin/secretin receptor axis in inflammatory cholangiocyte communication via extracellular vesicles. Sci Rep 7:11183
McDaniel, Kelly; Meng, Fanyin; Wu, Nan et al. (2017) Forkhead box A2 regulates biliary heterogeneity and senescence during cholestatic liver injury in miceā€”. Hepatology 65:544-559
McDaniel, Kelly; Huang, Li; Sato, Keisaku et al. (2017) The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury. J Biol Chem 292:11336-11347

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