Little is known about the signaling pathways that limit airway smooth muscle cell proliferation. In bovine tracheal myocytes, PDGF treatment and Rac1, each of which induce transcription from the cyclin D1 promoter, activate the stress-activated MAP kinases P38alpha and Jun amino-terminal kinase (JNK)-1, consistent with the notion that these MAP kinases play a role in growth regulation. Our preliminary studies show that selective activation of p38 pathway decreases PDGF and Rac1-induced cyclin D1 expression, suggesting that p38 functions a negative regulator of airway smooth muscle cell cycle progression. Further, activation of protein kinase C delta (PKCdelta) also decreases cyclin D1 expression, perhaps via activation of the p38 pathway. Finally, our pilot studies suggest that p38 attenuates transcription from the cyclin D1 promoter by reducing transactivation of the cAMP response element-binding protein (CREB)/ATF-2 response element. These data suggest a model in which growth factor stimulation of airway smooth muscle cells results in the simultaneous activation of both mitogenic and anti-mitogenic pathways, perhaps as a mechanism to prevent excessive cell proliferation. To determine the potential roles of p38 and PKCdelta in the regulation of transcription from the cyclin D1 promoter, we propose the following Specific Aims: 1. Determine the roles of the p38 and JNK MAP kinases in the regulation of cyclin D1 expression in airway smooth muscle cells. We will determine the effects of inhibition and activation of p38 and JNK on transcription from the cyclin D1 promoter, cyclin D1 protein abundance, and cell cycle progression. We will also determine the effects of inhibition and activation of p38 on ERK activation. 2. Determine the role of PKCdelta in the regulation of cyclin D1 expression in airway smooth muscle cells. We will assess PKCdelta translocation and activation following PDGF treatment of bovine tracheal myocytes. We will also determine the effects of inhibition or activation of PKCdelta on p38alpha activity and cyclin D1 expression, and whether p38 is required for PKCdelta-mediated suppression of cyclin D1 promoter activity. To determine the site where PKCdelta enters the p38 pathway, we will examine the requirement of PKCdelta for p38alpha activation by upstream signaling intermediates. 3. Determine the mechanism by which p38 MAP kinase attenuates transcription from the cyclin D1 promoter in airway smooth muscle cells. We will examine the effects of inhibitors and activators of p38 on CREB-1 and ATF-2 phosphorylation, DNA binding and CREB/ATF-2 transactivation. DNA binding proteins will be determined by supershift studies. Finally, we will assess the effects of dominant-negative inhibitors of CREB-1 and ATF-2 on transcription from the cyclin D1 promoter. Insight aired from these studies may shed light on a novel anti- mitogenic signaling pathway that may operate in asthma and other disease states in which abnormal cell proliferation is a feature, and lead to therapeutic interventions.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL054685-07
Application #
6389499
Study Section
Special Emphasis Panel (ZRG1-SSS-3 (03))
Program Officer
Noel, Patricia
Project Start
1995-08-03
Project End
2004-06-30
Budget Start
2001-07-01
Budget End
2002-06-30
Support Year
7
Fiscal Year
2001
Total Cost
$302,000
Indirect Cost
Name
University of Chicago
Department
Pediatrics
Type
Schools of Medicine
DUNS #
225410919
City
Chicago
State
IL
Country
United States
Zip Code
60637
Deng, Huan; Hershenson, Marc B; Lei, Jing et al. (2010) Pulmonary artery smooth muscle hypertrophy: roles of glycogen synthase kinase-3beta and p70 ribosomal S6 kinase. Am J Physiol Lung Cell Mol Physiol 298:L793-803
Goldsmith, Adam M; Bentley, J Kelley; Zhou, Limei et al. (2006) Transforming growth factor-beta induces airway smooth muscle hypertrophy. Am J Respir Cell Mol Biol 34:247-54
Zhou, Limei; Goldsmith, Adam M; Bentley, J Kelley et al. (2005) 4E-binding protein phosphorylation and eukaryotic initiation factor-4E release are required for airway smooth muscle hypertrophy. Am J Respir Cell Mol Biol 33:195-202
Hershenson, Marc B (2004) p21Waf1/Cip1 and the prevention of oxidative stress. Am J Physiol Lung Cell Mol Physiol 286:L502-5
Halayko, Andrew J; Kartha, Sreedharan; Stelmack, Gerald L et al. (2004) Phophatidylinositol-3 kinase/mammalian target of rapamycin/p70S6K regulates contractile protein accumulation in airway myocyte differentiation. Am J Respir Cell Mol Biol 31:266-75
Zhou, Limei; Li, Jing; Goldsmith, Adam M et al. (2004) Human bronchial smooth muscle cell lines show a hypertrophic phenotype typical of severe asthma. Am J Respir Crit Care Med 169:703-11
Zhou, Limei; Hershenson, Marc B (2003) Mitogenic signaling pathways in airway smooth muscle. Respir Physiol Neurobiol 137:295-308
Abe, Mark K; Saelzler, Matthew P; Espinosa 3rd, Rafael et al. (2002) ERK8, a new member of the mitogen-activated protein kinase family. J Biol Chem 277:16733-43
Page, Kristen; Li, Jing; Corbit, Kevin C et al. (2002) Regulation of airway smooth muscle cyclin D1 transcription by protein kinase C-delta. Am J Respir Cell Mol Biol 27:204-13
Page, K; Li, J; Hershenson, M B (2001) p38 MAP kinase negatively regulates cyclin D1 expression in airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 280:L955-64

Showing the most recent 10 out of 24 publications