Adult human aortic smooth muscle cells in culture produce active TGF-beta

1993 ◽  
Vol 265 (2) ◽  
pp. C571-C576 ◽  
Author(s):  
H. L. Kirschenlohr ◽  
J. C. Metcalfe ◽  
P. L. Weissberg ◽  
D. J. Grainger
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Doubling Time ◽  
Muscle Cells ◽  
Lung Epithelial Cells ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Tgf Beta ◽  
Adult Human

Vascular smooth muscle cells (VSMC) from adult human aortas proliferated in culture in response to fetal calf serum (FCS) with a population doubling time of 70-85 h compared with 35 +/- 5 h for VSMC derived from adult rat aortas. Medium conditioned on cultures prepared from aortas from three different donors and mixed 1:1 with fresh Dulbecco's modified Eagle's medium plus 20% FCS [human conditioned medium (HCM)] reduced the rate of proliferation of rat VSMC by 46 +/- 6% (n = 3) after 48 h compared with cells in fresh medium. HCM did not reduce the proportion (> 65%) of rat VSMC that entered DNA synthesis but delayed entry into mitosis by at least 18 h. This effect was similar to previous observations of the action of transforming growth factor-beta (TGF-beta) on rat VSMC (G. K. Owens, A. A. Geisterfer, Y. W. Yang, and A. Komoriya. J. Cell Biol. 107: 771-780, 1988). A TGF-beta assay using DNA synthesis in mink lung epithelial cells confirmed that human, but not rat, VSMC in culture secrete active TGF-beta. Addition of a neutralizing antibody to TGF-beta to human VSMC in the presence of 20% FCS decreased the population doubling time from 74 +/- 3 to 46 +/- 6 h (n = 3). These observations demonstrate that the long population doubling time of human VSMC is due to the production of active TGF-beta and to an inhibitory autocrine loop.

TGF-beta 1 potentiates growth factor-stimulated proliferation of vascular smooth muscle cells in genetic hypertension

1992 ◽  
Vol 263 (2) ◽  
pp. C420-C428 ◽  
Author(s):  
J. Saltis ◽  
A. Agrotis ◽  
A. Bobik
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Mrna Expression ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Tgf Beta ◽  
Spontaneously Hypertensive

We have examined the interactions between transforming growth factor-beta 1 (TGF-beta 1) and epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), or platelet-derived growth factor (PDGF) isoforms PDGF-AB and PDGF-BB on the proliferation of vascular smooth muscle cells isolated from the spontaneously hypertensive rat. TGF-beta 1 alone stimulated [3H]thymidine incorporation approximately twofold without a corresponding increase in cell number. In combination, TGF-beta 1 action was synergistic in further stimulating both DNA synthesis and cell proliferation 100-300% above the responses elicited by each growth factor. To gain further insight into the mechanism responsible for this potentiation, we examined the interaction between TGF-beta 1 and EGF. The synergistic interaction between TGF-beta 1 and EGF on DNA synthesis was independent of initial cell density. This effect of TGF-beta 1 was initiated early in the G1 phase of the cell cycle and did not appear to be mediated through the mobilization of Ca2+ or alterations in c-jun mRNA expression. However, in the presence of both TGF-beta 1 and EGF, there was a sustained elevation of c-myc mRNA levels over a 24-h period. These results suggest that TGF-beta 1 may interact with other growth factors in vivo to enhance their proliferative action on vascular smooth muscle of spontaneously hypertensive rats via mechanisms dependent on c-myc mRNA expression.

Autocrine Induction of DNA Synthesis by Mechanical Injury of Cultured Smooth Muscle Cells

1996 ◽  
Vol 16 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Federico Calara ◽  
Sean Ameli ◽  
Anna Hultgårdh-Nilsson ◽  
Bojan Cercek ◽  
Joel Kupfer ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Muscle Cells ◽  
Mechanical Injury ◽  
Cultured Smooth Muscle Cells

scholarly journals Transforming growth factor-beta-induced growth inhibition and cellular hypertrophy in cultured vascular smooth muscle cells.

1988 ◽  
Vol 107 (2) ◽  
pp. 771-780 ◽  
Author(s):  
G K Owens ◽  
A A Geisterfer ◽  
Y W Yang ◽  
A Komoriya
Keyword(s):  
Cell Cycle ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Muscle Cells ◽  
Tgf Beta ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Cellular Hypertrophy

We have explored the hypothesis that hypertrophy of vascular smooth muscle cells may be regulated, in part, by growth inhibitory factors that alter the pattern of the growth response to serum mitogens by characterizing the effects of the potent growth inhibitor, transforming growth factor-beta (TGF-beta), on both hyperplastic and hypertrophic growth of cultured rat aortic smooth muscle cells. TGF-beta inhibited serum-induced proliferation of rat aortic smooth muscle cells (ED50 = 2 pM); this is consistent with previously reported observations in bovine aortic smooth muscle cells (Assoian et al. 1982. J. Biol. Chem. 258:7155-7160). Growth inhibition was due in part to a greater than twofold increase in the cell cycle transit time in cells that continued to proliferate in the presence of TGF-beta. TGF-beta concurrently induced cellular hypertrophy as assessed by flow cytometric analysis of cellular protein content (47% increase) and forward angle light scatter (32-50% increase), an index of cell size. In addition to being time and concentration dependent, this hypertrophy was reversible. Simultaneous flow cytometric evaluation of forward angle light scatter and cellular DNA content demonstrated that TGF-beta-induced hypertrophy was not dependent on withdrawal of cells from the cell cycle nor was it dependent on growth arrest of cells at a particular point in the cell cycle in that both cycling cells in the G2 phase of the cell cycle and those in G1 were hypertrophied with respect to the corresponding cells in vehicle-treated controls. Chronic treatment with TGF-beta (100 pM, 9 d) was associated with accumulation of cells in the G2 phase of the cell cycle in the virtual absence of cells in S phase, whereas subsequent removal of TGF-beta from these cultures was associated with the appearance of a significant fraction of cycling cells with greater than 4c DNA content, consistent with development of tetraploidy. Results of these studies support a role for TGF-beta in the control of smooth muscle cell growth and suggest that at least one mechanism whereby hypertrophy and hyperploidy may occur in this, as well as other cell types, is by alterations in the response to serum mitogens by potent growth inhibitors such as TGF-beta.

EGF and TGF-beta regulate neutral endopeptidase expression in renal vascular smooth muscle cells

1997 ◽  
Vol 272 (6) ◽  
pp. C1836-C1843 ◽  
Author(s):  
P. L. Tharaux ◽  
A. Stefanski ◽  
S. Ledoux ◽  
J. M. Soleilhac ◽  
R. Ardaillou ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Transforming Growth Factor ◽  
Muscle Cells ◽  
Neutral Endopeptidase ◽  
Tgf Beta ◽  
Renal Vascular

We recently reported that neutral endopeptidase (NEP) expression on renal vascular smooth muscle cells (VSMC) was downregulated in the presence of serum. Here we examine the role of epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-beta) in this downregulation and the consequences of the changes in NEP activity on their mitogenic effects. EGF inhibited NEP activity, whereas TGF-beta was stimulatory. Expression of the enzyme was studied by measuring the binding of [125I]RB-104, a specific NEP inhibitor, and the fluorescence intensity of NEP-labeled cells. Both parameters were decreased by EGF and were increased by TGF-beta. NEP mRNA expression in EGF-treated cells was reduced after 48 h. In contrast, it was increased in TGF-beta-treated cells. Interestingly, NEP inhibition influenced the mitogenic effect of EGF. Indeed, thiorphan, an NEP inhibitor, and an anti-NEP antibody decreased EGF-dependent [3H]thymidine incorporation and cell proliferation by approximately 50%. TGF-beta had no effect on VSMC growth. These results indicate that EGF but not TGF-beta participates in the downregulatory potency of serum on NEP expression in VSMC. They also demonstrate that the full effect of EGF on VSMC proliferation depends on intact NEP activity.

PDGF-BB-induced DNA synthesis is delayed by angiotensin II in vascular smooth muscle cells

1998 ◽  
Vol 274 (5) ◽  
pp. H1742-H1748 ◽  
Author(s):  
Gunilla Dahlfors ◽  
Yun Chen ◽  
Maria Wasteson ◽  
Hans J. Arnqvist
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Receptor Antagonist ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Β Receptor ◽  
Tgf Β1

The interaction of ANG II with platelet-derived growth factor (PDGF)-BB-induced DNA synthesis was studied in cultured rat aortic smooth muscle cells. PDGF-BB-induced DNA synthesis was delayed (∼6–8 h) by ANG II as shown by a time-course experiment. Losartan, an AT1-receptor antagonist, blocked the transient inhibitory effect of ANG II, whereas the AT2-receptor antagonist PD-123319 had no effect. Autocrine- or paracrine-acting transforming growth factor-β1 (TGF-β1), believed to be a mediator of ANG II-induced inhibitory effects, was not responsible for the delay of PDGF-BB-induced DNA synthesis, because a potent TGF-β1 neutralizing antibody could not reverse this effect of ANG II, nor was the delay of the PDGF-BB effect caused by inhibition of PDGF-β-receptor phosphorylation as shown by Western blot analysis of immunoprecipitated PDGF-β receptor. In conclusion, our results show that ANG II can exert a transient inhibitory effect on PDGF-BB-induced proliferation via the AT1 receptor.

Cyclic stretch activates p38 SAPK2-, ErbB2-, and AT1-dependent signaling in bladder smooth muscle cells

2000 ◽  
Vol 279 (4) ◽  
pp. C1155-C1167 ◽  
Author(s):  
Hiep T. Nguyen ◽  
Rosalyn M. Adam ◽  
Samuel H. Bride ◽  
John M. Park ◽  
Craig A. Peters ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Protein Kinase ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Mapk Pathway ◽  
Muscle Cells ◽  
Cyclic Stretch ◽  
Bladder Smooth Muscle ◽  
Erk Mapk

Cyclic mechanical stretch of bladder smooth muscle cells (SMC) increases rates of DNA synthesis and stimulates transcription of the gene for heparin-binding epidermal growth factor-like growth factor (HB-EGF), an ErbB1/EGF receptor ligand that has been linked to hypertrophic bladder growth. In this study we sought to clarify the signaling pathways responsible for mechanotransduction of the stretch stimulus. HB-EGF mRNA levels, DNA synthesis, and AP-1/Ets DNA binding activities were induced by repetitive stretch of primary culture rat bladder SMC. Inhibitors of the p38 SAPK2 pathway, the angiotensin receptor type 1 (AT1), and the ErbB2 tyrosine kinase reduced each of these activities, while an inhibitor of the extracellular signal-regulated kinase mitogen-activated protein kinase (Erk-MAPK) pathway had no effect. Stretch rapidly activated stress-activated protein kinase 2 (p38 SAPK2) and Jun NH2-terminal kinase (JNK)/SAPK pathways but not the Erk-MAPK pathway and induced ErbB2 but not ErbB1 phosphorylation. Angiotensin II (ANG II) a bladder SMC mitogen previously linked to the stretch response, did not activate ErbB2, and ErbB2 activation occurred in response to stretch in the presence of an ANG receptor inhibitor, indicating that activation of the AT1-mediated pathway and the ErbB2-dependent pathway occurs by independent mechanisms. p38 SAPK2 and JNK/SAPK signaling also appeared to be independent of the ErbB2 and AT1 pathways. These findings indicate that stretch-stimulated DNA synthesis and gene expression in normal bladder SMC occur via multiple independent receptor systems (e.g., AT1 and ErbB2) and at least one MAPK pathway (p38 SAPK2). Further, we show that the Erk-MAPK pathway, which in most systems is linked to receptor-dependent cell growth responses, is not involved in progression to DNA synthesis or in the response of the HB-EGF gene to mechanical forces.

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