AJP - Lung Cellular and Molecular Physiology, Vol 273, Issue 6 1276-L1284, Copyright © 1997 by American Physiological Society

ARTICLES

Selected isozymes of PKC contribute to augmented growth of fetal and neonatal bovine PA adventitial fibroblasts

M. Das, K. R. Stenmark, L. J. Ruff and E. C. Dempsey
Cardiovascular Pulmonary Laboratori, University of Colorado Health Sciences Center, Denver 80262, USA.

We sought to determine which isozymes of protein kinase C (PKC) contribute to the increased proliferation of immature bovine pulmonary artery (PA) adventitial fibroblasts. Seven were identified in lysates of neonatal PA fibroblasts by Western blot: three Ca2+ dependent (alpha, beta I, and beta II) and four Ca2+ independent (delta, epsilon, zeta, and mu). Four isozymes (gamma, eta, theta, and iota) were not detected in fibroblasts isolated at any developmental stage. Of the seven detected isozymes, only PKC-alpha and -beta II protein levels were higher in fetal and neonatal cells compared with adult fibroblasts. Their role in the enhanced growth of immature fibroblasts was then evaluated. The isozyme nonselective PKC inhibitor Ro-31-8220 was first compared with GF-109203X, a structural analog of Ro-31-8220 with relative specificity for the Ca(2+)-dependent isozymes of PKC. GF-109203X selectively inhibited the growth of immature cells and was nearly as potent as Ro-31-8220. Go-6976, a more specific inhibitor of the Ca(2+)-dependent isozymes, mimicked the antiproliferative effect of GF-109203X. PKC downregulation with 1 microM phorbol 12-myristate 13-acetate had the same selective antiproliferative effect on immature fibroblasts as GF-109203X and Go-6976. The protein levels of PKC-alpha and -beta II, but not of PKC-beta I, were completely degraded in response to phorbol 12-myristate 13-acetate pretreatment. These results suggest that PKC-alpha and -beta II are important in the augmented growth of immature bovine PA adventitial fibroblasts.

This article has been cited by other articles:

				K. R. Stenmark, E. Gerasimovskaya, R. A. Nemenoff, and M. Das Hypoxic Activation of Adventitial Fibroblasts: Role in Vascular Remodeling Chest, December 1, 2002; 122(6_suppl): 326S - 334S. [Abstract] [Full Text] [PDF]

				M. Das, E. C. Dempsey, J. T. Reeves, and K. R. Stenmark Selective expansion of fibroblast subpopulations from pulmonary artery adventitia in response to hypoxia Am J Physiol Lung Cell Mol Physiol, May 1, 2002; 282(5): L976 - L986. [Abstract] [Full Text] [PDF]

				E. C. Dempsey, A. C. Newton, D. Mochly-Rosen, A. P. Fields, M. E. Reyland, P. A. Insel, and R. O. Messing Protein kinase C isozymes and the regulation of diverse cell responses Am J Physiol Lung Cell Mol Physiol, September 1, 2000; 279(3): L429 - L438. [Abstract] [Full Text] [PDF]

				A. Paul, L. J. Torrie, G. J. McLaren, C. Kennedy, G. W. Gould, and R. Plevin P2Y Receptor-mediated Inhibition of Tumor Necrosis Factor alpha -stimulated Stress-activated Protein Kinase Activity in EAhy926 Endothelial Cells J. Biol. Chem., April 28, 2000; 275(18): 13243 - 13249. [Abstract] [Full Text] [PDF]

				M. Das, E. C. Dempsey, D. Bouchey, M. E. Reyland, and K. R. Stenmark Chronic Hypoxia Induces Exaggerated Growth Responses in Pulmonary Artery Adventitial Fibroblasts . Potential Contribution of Specific Protein Kinase C Isozymes Am. J. Respir. Cell Mol. Biol., January 1, 2000; 22(1): 15 - 25. [Abstract] [Full Text]

				S. Carlin, K. X. F. Yang, R. Donnelly, and J. L. Black Protein kinase C isoforms in human airway smooth muscle cells: activation of PKC-zeta during proliferation Am J Physiol Lung Cell Mol Physiol, March 1, 1999; 276(3): L506 - L512. [Abstract] [Full Text] [PDF]

				Z. Gao, T. Chen, M. J. Weber, and J. Linden A2B Adenosine and P2Y2 Receptors Stimulate Mitogen-activated Protein Kinase in Human Embryonic Kidney-293 Cells. CROSS-TALK BETWEEN CYCLIC AMP AND PROTEIN KINASE C PATHWAYS J. Biol. Chem., February 26, 1999; 274(9): 5972 - 5980. [Abstract] [Full Text] [PDF]