Endothelin-1 stimulates DNA synthesis and proliferation of pulmonary artery smooth muscle cells

1992 ◽  
Vol 263 (6) ◽  
pp. C1295-C1301 ◽  
Author(s):  
K. Janakidevi ◽  
M. A. Fisher ◽  
P. J. Del Vecchio ◽  
C. Tiruppathi ◽  
J. Figge ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Pulmonary Artery ◽  
Dna Synthesis ◽  
Synthetic Activity ◽  
Proliferative Potential ◽  
Endothelin 1 ◽  
Kinase C

Endothelin-1 (ET-1), a 21-amino acid peptide released from the endothelium, elicits a variety of biological effects that include vascular smooth muscle cell (VSMC) contraction, release of secondary mediators, and cell proliferation. The present study was undertaken to examine the proliferative potential of ET-1 toward pulmonary artery VSMC in culture. In the presence of low serum and epidermal growth factor (EGF), ET-1 stimulated marked DNA synthesis and proliferation of VSMC. The contributing factor from serum appeared to be platelet-derived growth factor (PDGF) because the antibody to PDGF eliminated the stimulatory activity. The antibody to EGF also prevented the stimulation, suggesting that both PDGF and EGF are required for the full expression of the VSMC growth-promoting activity of ET-1. A paradoxical aspect of ET-1 effect on VSMC was the ability of ET-1 to inhibit the EGF-stimulated DNA synthesis when the two factors were added together to a high baseline DNA synthetic activity. The inhibition was prevented if ET-1 was added 12-18 h after the addition of EGF or if ET-1 and EGF were added to a protein kinase C-depleted VSMC. The inhibition by ET-1 may be mediated by protein kinase C activation followed by inhibition of EGF binding to its receptor. The results indicate that ET-1 under appropriate conditions can modulate the growth of pulmonary artery VSMC in both positive and negative directions.

scholarly journals Mechanisms regulating cAMP-mediated growth of bovine neonatal pulmonary artery smooth muscle cells

1999 ◽  
Vol 276 (6) ◽  
pp. L1010-L1017 ◽  
Author(s):  
Alexandra Guldemeester ◽  
Kurt R. Stenmark ◽  
George H. Brough ◽  
Troy Stevens
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Pulmonary Artery ◽  
Growth Responses ◽  
Camp Content ◽  
Kinase C ◽  
Pulmonary Artery Smooth Muscle ◽  
Stimulation Of

Neonatal pulmonary artery smooth muscle cells (PASMCs) exhibit enhanced growth capacity and increased growth responses to mitogenic stimuli compared with adult PASMCs. Because intracellular signals mediating enhanced growth responses in neonatal PASMCs are incompletely understood, we questioned whether 1) Gq agonists increase cAMP content and 2) increased cAMP is proproliferative. Endothelin-1 and angiotensin II increased both cAMP content and proliferation in neonatal but not in adult PASMCs. Inhibition of protein kinase C and protein kinase A activity nearly eliminated the endothelin-1- and angiotensin II-induced growth of neonatal PASMCs. Moreover, cAMP increased proliferation in neonatal but not in adult cells. Protein kinase C-stimulated adenylyl cyclase was expressed in both cell types, suggesting that insensitivity to stimulation of cAMP in adult cells was not due to decreased enzyme expression. Our data collectively indicate that protein kinase C stimulation of cAMP is a critical signal mediating proliferation of neonatal PASMCs that is absent in adult PASMCs and therefore may contribute to the unique proproliferative phenotype of these neonatal cells.

Protein kinase C in cyclic stretch-induced nerve growth factor production by urinary tract smooth muscle cells

1995 ◽  
Vol 269 (4) ◽  
pp. C1018-C1024 ◽  
Author(s):  
K. Persson ◽  
J. J. Sando ◽  
J. B. Tuttle ◽  
W. D. Steers
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Urinary Tract ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Cyclic Stretch ◽  
Bladder Obstruction ◽  
Kinase C

Cyclic stretch of cultured urinary tract smooth muscle cells has been used to mimic some of the events that occur with bladder obstruction. The stretch stimulus induces production of nerve growth factor (NGF), which has been implicated in changes in bladder innervation. Stretch-induced NGF production was blocked by actinomycin. Involvement of protein kinase C (PKC) in the stretch-induced NGF production is strongly suggested by the following observations. Phorbol ester activators of PKC mimicked the stretch response as did platelet-derived growth factor (PDGF), which acts, in part, through generation of endogenous diacylglycerols. Both stretch- and PDGF-induced NGF production were blocked by prolonged incubation with phorbol ester to downregulate PKC. Western blot analysis confirmed partial downregulation of the Ca(2+)-dependent PKC-alpha and PKC-beta 1 and near complete downregulation of the Ca(2+)-independent PKC isozymes delta, epsilon, and zeta. The involvement of PKC in transducing a physical stimulus (stretch) into a biochemical response (NGF production) has implications for novel types of therapeutic intervention in ailments such as bladder obstruction.

Response of malignant glioma cell lines to activation and inhibition of protein kinase C-mediated pathways

1990 ◽  
Vol 73 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Ian F. Pollack ◽  
Margaret S. Randall ◽  
Matthew P. Kristofik ◽  
Robert H. Kelly ◽  
Robert G. Selker ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Growth Factor ◽  
Protein Kinase ◽  
Dna Synthesis ◽  
Malignant Glioma ◽  
Polymyxin B ◽  
Content Type ◽  
Rat Glioma ◽  
Kinase C ◽  
Low Passage

✓ To evaluate the role of protein kinase C-mediated pathways in the proliferation of malignant gliomas, this study examined the effect of a protein kinase C (PKC)-activating phorbol ester (12-O-tetradecanoyl-13-phorbol acetate or TPA) and a protein kinase C inhibitor (polymyxin B) on deoxyribonucleic acid (DNA) synthesis of malignant glioma cells in vitro. A serum-free chemically defined medium, MCDB 105, was employed for all studies. Two established human malignant glioma cell lines (T98G and U138), two rat glioma lines (9L and C6), and two low-passage human glioma lines (obtained from surgical specimens) were studied. With the exception of the C6 line, all tumors responded in a dose-dependent fashion to nanomolar concentrations of TPA with a median effective dose that varied from 0.5 ng/ml for the U138 glioma to 1 ng/ml for the T98G glioma. At optimal concentrations (5 to 10 ng/ml), TPA produced a two- to five-fold increase in the rate of DNA synthesis (p < 0.05) as assessed by incorporation of 3H-thymidine. However, TPA had no additive effect on the mitogenic response produced by epidermal growth factor (EGF) or platelet-derived growth factor (PDGF). Inhibition of PKC using the antibiotic polymyxin B (20 µg/ml) abolished the TPA-induced mitogenic response in the five responsive lines tested. In two tumors (U138 and 9L), polymyxin B also eliminated EGF-, PDGF-, and serum-induced DNA synthesis as well as abolishing baseline DNA synthesis. These cells remained viable, however, as assessed by trypan blue exclusion; after removal of polymyxin B from the medium, they were able to resume DNA synthesis in response to TPA and serum. In the three other tumors (T98G and the two low-passage human glioma lines), growth factor-induced and serum-induced DNA synthesis were inhibited by approximately 25% to 85%. It is concluded that PKC-mediated pathways affect DNA synthesis in the human malignant glial tumors studied. The response of the glioma cells to TPA is similar to the responses seen in fetal astrocytes, but differs significantly from those reported for normal adult glial cultures. Because the response of the 9L glioma to TPA is similar to the responses seen in the human tumors, the 9L rat glioma model may prove useful for examining the role of PKC-mediated pathways in controlling glioma growth in vivo.

scholarly journals Divergent regulation by growth factors and cytokines of 95 kDa and 72 kDa gelatinases and tissue inhibitors or metalloproteinases-1, -2, and -3 in rabbit aortic smooth muscle cells

1996 ◽  
Vol 315 (1) ◽  
pp. 335-342 ◽  
Author(s):  
Rosalind P. FABUNMI ◽  
Andrew H. BAKER ◽  
Edward J. MURRAY ◽  
Robert F. G. BOOTH ◽  
Andrew C. NEWBY
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Growth Factors ◽  
Growth Factor ◽  
Protein Kinase ◽  
Basement Membrane ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Tissue Inhibitors ◽  
Kinase C

The migration and proliferation of vascular smooth muscle cells (SMCs) during neointima formation in atherosclerosis and angioplasty restenosis is mediated by certain growth factors and cytokines, one action of which may be to promote basement-membrane degradation. To test this hypothesis further, the effects of such growth factors and cytokines on the synthesis of two basement-membrane-degrading metalloproteinases, namely the 72 kDa gelatinase (MMP-2, gelatinase A) and the 95 kDa gelatinase (MMP-9, gelatinase B) and three tissue inhibitors of metalloproteinases (TIMPs) was studied in primary cultured rabbit aortic SMCs. Expression of the 95 kDa gelatinase was increased by phorbol myristate acetate, foetal calf serum, thrombin and interleukin-1α (IL-1α); platelet-derived growth factor (PDGF) BB alone had no effect but acted synergistically with IL-1α. A selective protein kinase C inhibitor, Ro 31-8220, abolished induction of the 95 kDa gelatinase. In contrast, none of the agents tested modulated the synthesis of the 72 kDa gelatinase. We conclude that maximal up-regulation of 95 kDa gelatinase expression requires the concerted action of growth factors and inflammatory cytokines mediated, in part, by a protein kinase C-dependent pathway. TIMP-1 and TIMP-2 were highly expressed, and their synthesis was not affected by growth factors or cytokines. Expression of TIMP-3 mRNAs was, however, increased by PDGF and transforming growth factor β, especially in combination. Divergent regulation of gelatinase and TIMP expression implies that either net synthesis or net degradation of basement membrane can be mediated by appropriate combinations of growth factors and cytokines.

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