There is considerable evidence now available that supports an important rote for the serotonin (5-HT) transporter, a member of the NaCl- dependent transporter gene family, in the development of pulmonary vascular remodeling and hypertension. Transcription of this transporter is stimulated by hypoxia and the transporter participates in 5-HT-induced pulmonary artery (PA) smooth muscle cell (SMC) hyperplasia/hypertrophy. Based on our studies done largely during the last funding period, we hypothesize that there are specific intermediate intracellular signaling pathways through which the mitogenic action of 5-HT occurs (denoted in Figure 1). We plan in this proposal to further study these intermediate signals by: 1) examining the PA SMC NAD(P)H oxidase that is stimulated in response to 5-HT transport; 2) characterizing the role of Src-Fak non-receptor kinases in signal transduction, cyclin D1 gene regulation, cell growth and cytoskeletal reorganization produced by 5-HT; 3) evaluating transcription factors (in particular STAT and GATA) that may be linked to 5-HT transporter stimulation of SMC growth; and 4) assessing the role of a concomitant 5-HT4-like receptor action on the same SMC that can convert the growth stimulatory effect to a growth inhibitory one. For these studies we will use bovine PA SMCs, with which we have had considerable experience, but will shift to PA SMCs of the human, rat and mouse species as needed to answer specific questions, or where reagents being used require specific species homology. Methodologies will include, but not be limited to, Western and Northern analyses, electrophoretic mobility shift assays, immunoblotting, PCR technology, lipid-mediated transient transfections, adenoviralmediated gene transfer, and use of reporter gene constructs, all of which are ongoing in our laboratory. We anticipate that a fuller understanding of the intracellular processes responding to 5-HT transporter activation may allow development of new strategies for treating pulmonary hypertension.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL032723-22
Application #
7104982
Study Section
Lung Biology and Pathology Study Section (LBPA)
Program Officer
Denholm, Elizabeth M
Project Start
1984-07-01
Project End
2008-08-31
Budget Start
2006-09-01
Budget End
2008-08-31
Support Year
22
Fiscal Year
2006
Total Cost
$355,933
Indirect Cost
Name
Tufts University
Department
Type
DUNS #
079532263
City
Boston
State
MA
Country
United States
Zip Code
02111
Liu, Y; Fanburg, B L (2008) Phospholipase D signaling in serotonin-induced mitogenesis of pulmonary artery smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 295:L471-8
Merdek, Keith D; Jaffe, Aron B; Dutt, Parmesh et al. (2008) Alpha(E)-Catenin induces SRF-dependent transcriptional activity through its C-terminal region and is partly RhoA/ROCK-dependent. Biochem Biophys Res Commun 366:717-23
Finlay, Geraldine A; Malhowski, Amy J; Liu, Yingling et al. (2007) Selective inhibition of growth of tuberous sclerosis complex 2 null cells by atorvastatin is associated with impaired Rheb and Rho GTPase function and reduced mTOR/S6 kinase activity. Cancer Res 67:9878-86
Liu, Yinglin; Li, Min; Warburton, Rod R et al. (2007) The 5-HT transporter transactivates the PDGFbeta receptor in pulmonary artery smooth muscle cells. FASEB J 21:2725-34
Liu, Yinglin; Fanburg, Barry L (2006) Serotonin-induced growth of pulmonary artery smooth muscle requires activation of phosphatidylinositol 3-kinase/serine-threonine protein kinase B/mammalian target of rapamycin/p70 ribosomal S6 kinase 1. Am J Respir Cell Mol Biol 34:182-91
Preston, Ioana R; Hill, Nicholas S; Warburton, Rod R et al. (2006) Role of 12-lipoxygenase in hypoxia-induced rat pulmonary artery smooth muscle cell proliferation. Am J Physiol Lung Cell Mol Physiol 290:L367-74
Schultz, Kelly; Fanburg, Barry L; Beasley, Debbie (2006) Hypoxia and hypoxia-inducible factor-1alpha promote growth factor-induced proliferation of human vascular smooth muscle cells. Am J Physiol Heart Circ Physiol 290:H2528-34
Day, Regina M; Agyeman, Abena S; Segel, Michael J et al. (2006) Serotonin induces pulmonary artery smooth muscle cell migration. Biochem Pharmacol 71:386-97
Finlay, Geraldine A; Thannickal, Victor J; Fanburg, Barry L et al. (2005) Platelet-derived growth factor-induced p42/44 mitogen-activated protein kinase activation and cellular growth is mediated by reactive oxygen species in the absence of TSC2/tuberin. Cancer Res 65:10881-90
Simon, Amy R; Severgnini, Mariano; Takahashi, Satoe et al. (2005) 5-HT induction of c-fos gene expression requires reactive oxygen species and Rac1 and Ras GTPases. Cell Biochem Biophys 42:263-76

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