Submitted on January 23, 2009
Revised on March 30, 2009
Accepted on April 16, 2009
Follicle Stimulating Hormone Increases Cholangiocyte Proliferation by an Autocrine Mechanism via cAMP-dependent Phosphorylation of ERK1/2 and Elk-1
Romina Mancinelli1, Paolo Onori2, Eugenio Gaudio3, Sharon DeMorrow4, Antonio Franchitto3, Heather Francis5, Shannon S Glaser6, Guido Carpino3, Julie Venter7, Domenico Alvaro3, Shelley Kopriva1, Mellanie White8, Ashley Kossie1, Jennifer Savage1, and Gianfranco Alpini9*
1 Texas A&M Health Science Center, College of Medicine
2 University of L'Aquila, L'Aquila, Italy
3 University of Rome
4 S&W Hospital, Texas A&M HSC
5 Scott & White Hospital
6 Texas A&M Univ. HSC/ Scott and White Hospital
7 The Texas A&M University System Health Science Center, College of Medicine
8 Central Texas Veterans Health Care System
9 Central Texas Veterans Health Care System and Texas A & M Health Science Center College of Medicine
* To whom correspondence should be addressed. E-mail: galpini{at}tamu.edu.
Sex hormones regulate cholangiocyte hyperplasia in bile duct ligated (BDL) rats. We studied whether follicle-stimulating hormone (FSH) regulates cholangiocyte proliferation. FSH receptor (FSHR) and FSH expression was evaluated in liver sections, purified cholangiocytes, and cholangiocyte cultures (NRICC). In vivo, normal female and male rats were treated with FSH, or immediately after BDL with Antide (a gonadotropin releasing hormone antagonist blocking FSH secretion) or a neutralizing FSH antibody for 1 week. We evaluated: (i) cholangiocyte proliferation in sections and cholangiocytes; and (ii) changes in secretin-stimulated cAMP (functional index of cholangiocyte growth) levels, and ERK1/2 and Elk-1 phosphorylation. NRICC were stimulated with FSH before evaluating proliferation, cAMP/IP3 levels, and ERK1/2 and Elk-1 phosphorylation. To determine if FSH regulates cholangiocyte proliferation by an autocrine mechanism, we evaluated the effects of: (i) cholangiocyte supernatant (containing FSH) on NRICC proliferation; and (ii) FSH silencing in NRICC before measuring proliferation, and ERK1/2 and Elk-1 phosphorylation. Results: Cholangiocytes and NRICC express FSHR, FSH and secrete FSH. In vivo administration of FSH to normal rats increased, whereas administration of Antide and anti-FSH antibody to BDL rats decreased: (i) ductal mass; and (ii) secretin-stimulated cAMP levels, proliferation, and ERK1/2 and Elk-1 phosphorylation in cholangiocytes compared to controls. In NRICC, FSH increased cholangiocyte proliferation, cAMP levels and ERK1/2 and Elk-1 phosphorylation. The supernatant of cholangiocytes increased NRICC proliferation, inhibited by preincubation with anti-FSH antibody. Silencing of FSH gene decreases cholangiocyte proliferation and ERK1/2 and Elk-1 phosphorylation. Modulation of cholangiocyte FSH expression may be important for the management of cholangiopathies.
