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 #
5R01DK062975-07
Application #
8512706
Study Section
Hepatobiliary Pathophysiology Study Section (HBPP)
Program Officer
Sherker, Averell H
Project Start
2002-12-01
Project End
2015-07-31
Budget Start
2013-08-01
Budget End
2014-07-31
Support Year
7
Fiscal Year
2013
Total Cost
$267,296
Indirect Cost
$51,496
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, Lindsey L; Meng, Fanyin; Venter, Julie K et al. (2016) Knockout of microRNA-21 reduces biliary hyperplasia and liver fibrosis in cholestatic bile duct ligated mice. Lab Invest 96:1256-1267
Wu, Nan; Meng, Fanyin; Invernizzi, Pietro et al. (2016) The secretin/secretin receptor axis modulates liver fibrosis through changes in transforming growth factor-β1 biliary secretion in mice. Hepatology 64:865-79
Han, Yuyan; Meng, Fanyin; Venter, Julie et al. (2016) miR-34a-dependent overexpression of Per1 decreases cholangiocarcinoma growth. J Hepatol 64:1295-304
Wan, Ying; Garner, Jessica; Wu, Nan et al. (2016) Role of stem cells during diabetic liver injury. J Cell Mol Med 20:195-203
Sato, Keisaku; Hall, Chad; Glaser, Shannon et al. (2016) Pathogenesis of Kupffer Cells in Cholestatic Liver Injury. Am J Pathol 186:2238-47
Hall, Chad; Sato, Keisaku; Wu, Nan et al. (2016) Regulators of Cholangiocyte Proliferation. Gene Expr :
Sato, Keisaku; Meng, Fanyin; Glaser, Shannon et al. (2016) Exosomes in liver pathology. J Hepatol 65:213-21
McDaniel, Kelly; Meng, Fanyin; Wu, Nan et al. (2016) Forkhead box A2 regulated biliary heterogeneity and senescence during cholestatic liver injury. Hepatology :
Meng, Luke; Quezada, Morgan; Levine, Phillip et al. (2015) Functional role of cellular senescence in biliary injury. Am J Pathol 185:602-9
Ray, Debolina; Han, Yuyan; Franchitto, Antonio et al. (2015) Gonadotropin-releasing hormone stimulates biliary proliferation by paracrine/autocrine mechanisms. Am J Pathol 185:1061-72

Showing the most recent 10 out of 76 publications