Assistant Professor
Department of Internal Medicine
Phone: 254-742-7058
Fax: 254-724-5944 
Email: sglaser@tamu.edu

Education

B.S. Biochemistry, Texas A&M University (1991)
M.S. Biochemistry, Texas A&M University (1994)
Ph.D. Medical Sciences, Texas A&M University System Health Science Center (2006)

Research Interests

Proliferation of cholangiocytes is critical for the maintenance of biliary mass and secretory function during the pathogenesis of chronic cholestatic liver diseases, such as primary biliary cirrhosis (PBC), and primary sclerosing cholangitis (PSC).  We have previously demonstrated that proliferating cholangiocytes serve as a neuroendocrine compartment during liver disease pathogenesis and as such secrete and respond to hormones and neuropeptides contributing to the autocrine and paracrine pathways that modulate liver inflammation and fibrosis. We have recently obtained novel data indicating that cholangiocytes express a local renin-angiotensin-system (RAS) and that chronic administration of angiotensin II (Ang II) increases the proliferation of normal rat cholangiocytes and enhances the proliferation of cholangiocytes during extrahepatic cholestasis induced by bile duct ligation (BDL).  We have also obtained unique in vitro preliminary data demonstrating that mechanical stress, which occurs during extrahepatic obstructive disorders, induces cholangiocyte proliferation via mechanical activation of the angiotensin type 1 receptor (AT1). AT1 is known to regulate proliferation as a G-protein coupled receptor binding Ang II and as a mechanoreceptor that can induce proliferation in response to mechanical stress in the absence of Ang II in other cell types. However, the contribution of the RAS to the pathogenesis of cholangiocytes during cholestatic liver diseases remains to be established.  The long-range natural progression of my research program will be to determine how activation of the local RAS mechanical stress and other factors contribute to biliary fibrosis during cholestatic liver diseases.

Selected Publications

Wise C, Pilanthanond M, Perry B, Alpini G, McNeal M, Glaser S. Mechanisms of biliary carcinogenesis and growth. World Journal of Gastroenterology, (In Press: March, 2008)

Glaser S, Ueno Y, DeMorrow S, Chiasson V, Katki K, Venter J, Francis H, Dickerson I, DiPette D J, Supowit S, and Alpini G. Knockout of a-calcitonin gene-related peptide prevents growth of cholangiocytes induced by extrahepatic bile duct obstruction.  Lab Invest. 2007 Sep;87(9):914-26.

Francis H, Alvaro D, Glaser S, Venter J, LeSage G, Marucci L, Benedetti A, Reichenbach R, Ueno Y, DeMorrow S, Mancino MG, and Alpini G.  The a-2 adrenergic receptor agonist, UK 14,304, inhibits secretin-stimulated ductal secretion by impairing activation of the cAMP system.  Am J Physiol Cell Physiol. 2007 Oct;293(4):C1252-62.

Alvaro D, Mancino MG, Glaser S, Gaudio E, Marzioni M, Francis H, Alpini G. Proliferating cholangiocytes: a neuroendocrine compartment in the diseased liver. Gastroenterology. 2007 Jan;132(1):415-31.

Marzioni M, Ueno Y, Glaser S, Francis H, Benedetti A, Alvaro D, Venter J, Fava G, Alpini G. Cytoprotective effects of taurocholic acid feeding on the biliary tree after adrenergic denervation of the liver.  Liver Int. 2007 May;27(4):558-68.

Taffetani S, Glaser S, Francis H, DeMorrow S, Ueno Y, Alvaro D, Marucci L, Marzioni M, Fava G, Venter J, Vaculin S, Vaculin B, Lam IP, Lee VH, Gaudio E, Carpino G, Benedetti A, Alpini G. Prolactin stimulates the proliferation of normal female cholangiocytes by differential regulation of Ca2+-dependent PKC isoforms. BMC Physiol. 2007 Jul 19;7:6.

Fava G, Ueno Y, Glaser S, Francis H, DeMorrow S, Marucci L, Marzioni M, Benedetti A, Venter J, Vaculin B, and Alpini G.  Thyroid hormone inhibits biliary growth in rats by IP3/Ca2+/PKC-dependent downregulation of SRC/ERK1/2.  Am J Physiol Cell Physiol 292:1467-1475, 2007.

DeMorrow S, Glaser S,  Francis H, Venter J, Vaculin B, Vaculin S, and Alpini G. Opposing actions of endocannabinoids on cholangiocarcinoma growth: recruitment of death receptor in lipid rafts.  J Biol Chem 282: 13098-13113, 2007.

Glaser S, Alvaro D, Francis H, Ueno Y, De Morrow S, Marucci L, Benedetti A, Marzioni M, Mancino MG, JL Phinizy, R Reichenbach, G Fava, R Summers, J Venter, and G Alpini. Adrenergic receptor agonists prevent bile duct injury induced by adrenergic denervation by increased cAMP levels and activation of Akt. Am J Physiol 290:G813-G826, 2006.

Marzioni M, Francis H, Benedetti A, Ueno Y, Fava G, Venter J, Reichenbach R, Alpini G, and Glaser S. Ca2+-dependent cytoprotective effects of urso- and tauroursodeoxycholic acid on the biliary epithelium in a rat model of cholestasis and loss of bile ducts.  Am J Pathol 168:398-409, 2006.