scholarly journals Arterial smooth muscle cells in vivo: relationship between actin isoform expression and mitogenesis and their modulation by heparin.

1988 ◽  
Vol 107 (5) ◽  
pp. 1939-1945 ◽  
Author(s):  
A W Clowes ◽  
M M Clowes ◽  
O Kocher ◽  
P Ropraz ◽  
C Chaponnier ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
In Vitro Translation ◽  
In Vivo Model ◽  
Growth Fraction ◽  
Mrna Levels ◽  
Actin Isoforms ◽  
Actin Mrna

Quiescent smooth muscle cells (SMC) in normal artery express a pattern of actin isoforms with alpha-smooth muscle (alpha SM) predominance that switches to beta predominance when the cells are proliferating. We have examined the relationship between the change in actin isoforms and entry of SMC into the growth cycle in an in vivo model of SMC proliferation (balloon injured rat carotid artery). alpha SM actin mRNA declined and cytoplasmic (beta + gamma) actin mRNAs increased in early G0/G1 (between 1 and 8 h after injury). In vivo synthesis and in vitro translation experiments demonstrated that functional alpha SM mRNA is decreased 24 h after injury and is proportional to the amount of mRNA present. At 36 h after injury, SMC prepared by enzymatic digestion were sorted into G0/G1 and S/G2 populations; only the SMC committed to proliferate (S/G2 fraction) showed a relative slight decrease in alpha SM actin and, more importantly, a large decrease in alpha SM actin mRNA. A switch from alpha SM predominance to beta predominance was present in the whole SMC population 5 d after injury. To determine if the change in actin isoforms was associated with proliferation, we inhibited SMC proliferation by approximately 80% with heparin, which has previously been shown to block SMC in late G0/G1 and to reduce the growth fraction. The switch in actin mRNAs and synthesis at 24 h was not prevented; however, alpha SM mRNA and protein were reinduced at 5 d in the heparin-treated animals compared to saline-treated controls. These results suggest that in vivo the synthesis of actin isoforms in arterial SMC depends on the mRNA levels and changes after injury in early G0/G1 whether or not the cells subsequently proliferate. The early changes in actin isoforms are not prevented by heparin, but they are eventually reversed if the SMC are kept in the resting state by the heparin treatment.

scholarly journals Perlecan regulates Oct-1 gene expression in vascular smooth muscle cells.

1997 ◽  
Vol 8 (6) ◽  
pp. 999-1011 ◽  
Author(s):  
M C Weiser ◽  
N A Grieshaber ◽  
P E Schwartz ◽  
R A Majack
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Type Iv Collagen ◽  
Muscle Cells ◽  
Mrna Levels ◽  
Type Iv

Vascular smooth muscle cells (SMCs) are very quiescent in the mature vessel and exhibit a remarkable phenotype-dependent diversity in gene expression that may reflect the growth responsiveness of these cells under a variety of normal and pathological conditions. In this report, we describe the expression pattern of Oct-1, a member of a family of transcription factors involved in cell growth processes, in cultured and in in vivo SMCs. Oct-1 mRNA was undetectable in the contractile-state in vivo SMCs; was induced upon disruption of in vivo SMC-extracellular matrix interactions; and was constitutively expressed by cultured SMCs. Oct-1 transcripts were repressed when cultured SMCs were plated on Engelbreth-Holm-Swarm tumor-derived basement membranes (EHS-BM) but were rapidly induced after disruption of SMC-EHS-BM contacts; reexpression was regulated at the transcriptional level. To identify the EHS-BM component involved in the active repression of Oct-1 mRNA expression, SMCs were plated on laminin, type IV collagen, fibronectin, or perlecan matrices. Oct-1 mRNA levels were readily detectable when SMCs were cultured on matrices composed of laminin, type IV collagen, or fibronectin but were repressed when SMCs were cultured on perlecan matrices. Finally, the Oct-1-suppressing activity of EHS-BM was sensitive to heparinase digestion but not to chondroitinase ABC or hyaluronidase digestion, suggesting that the heparan sulfate side chains of perlecan play a biologically important role in negatively regulating the expression of Oct-1 transcripts.

scholarly journals Steroid-sensitive gene-1 is an androgen-regulated gene expressed in prostatic smooth muscle cells in vivo

2001 ◽  
Vol 26 (3) ◽  
pp. 175-184 ◽  
Author(s):  
D Marcantonio ◽  
LE Chalifour ◽  
MA Alaoui-Jamali And H T Huynh ◽  
MA Alaoui-Jamali ◽  
MA Alaoui-Jamali ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Mrna Expression ◽  
Muscle Cells ◽  
Ventral Prostate ◽  
Mrna Levels ◽  
Rat Ventral Prostate ◽  
Steroid Sensitive

Steroid-sensitive gene-1 (SSG1) is a novel gene we cloned, found regulated by 17beta-estradiol in the rat uterus and mammary gland, and over-expressed in 7,12-dimethylbenz(a)anthracene-induced rat mammary tumors. We show here that SSG1 mRNA and protein expression are regulated by androgens in the rat ventral prostate. Increases in SSG1 mRNA levels were detected by Northern blotting after 24 h and reached a 27-fold peak 96 h following castration, relative to SSG1 mRNA expression in sham-operated rats. Dihydrotestosterone or testosterone supplementation of castrated rats prevented this rise in SSG1 mRNA. In contrast with SSG1 mRNA expression, SSG1 protein was decreased 16-fold 2 weeks following castration but was at control levels in the prostates of castrated rats receiving dihydrotestosterone or testosterone. Although SSG1 is regulated by androgens in vivo, treatment of LnCap cells with dihydrotestosterone, cyproterone acetate or flutamide did not result in the regulation of SSG1 protein levels in vitro. Immunofluorescence studies show that SSG1 is mainly expressed in prostatic smooth muscle cells. These results indicate that SSG1 is an androgen-regulated gene that is expressed in the smooth muscle component of the rat ventral prostate in vivo.

Inducible PDGF A-chain transcription in smooth muscle cells is mediated by Egr-1 displacement of Sp1 and Sp3

1997 ◽  
Vol 273 (3) ◽  
pp. H1415-H1426 ◽  
Author(s):  
E. S. Silverman ◽  
L. M. Khachigian ◽  
V. Lindner ◽  
A. J. Williams ◽  
T. Collins
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Arterial Injury ◽  
In Vivo Model ◽  
Binding Assays ◽  
Base Pairs ◽  
A Chain

Platelet-derived growth factor (PDGF) A-chain is expressed by vascular smooth muscle cells (SMC) in a variety of pathological settings. Phorbol 12-myristate 13-acetate (PMA) increases A-chain transcription and was used as a model agonist. Transient transfection analysis identified a region in the promoter that is required for inducibility, located between base pairs -71 and -55 from the transcription start site. This region contains overlapping recognition elements for members of the Sp and Egr families. Egr-1 transcript and protein increased after PMA treatment, whereas Sp1 and Sp3 levels remain unchanged. Egr-1 expression and PDGF A-chain promoter activity also increased in cells exposed to PDGF or mechanical injury. In vitro binding assays demonstrated that Egr-1, Sp1, and Sp3 can bind to this promoter region and that increasing Egr-1 can displace both Sp1 and Sp3. In an in vivo model of arterial injury, Egr-1 expression was induced concurrently with the expression of PDGF-A in SMC. Displacement of Sp1 and Sp3 by Egr-1 is correlated with inducible PDGF A-chain expression in the vessel wall.

scholarly journals Stromal cells from human long-term marrow cultures are mesenchymal cells that differentiate following a vascular smooth muscle differentiation pathway

Blood ◽  
1993 ◽  
Vol 82 (1) ◽  
pp. 66-76 ◽  
Author(s):  
MC Galmiche ◽  
VE Koteliansky ◽  
J Briere ◽  
P Herve ◽  
P Charbord
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Stromal Cells ◽  
Muscle Cells ◽  
Mesenchymal Cells ◽  
Myoid Cells ◽  
Marrow Cultures

In human long-term marrow cultures connective tissue-forming stromal cells are an essential cellular component of the adherent layer where granulomonocytic progenitors are generated from week 2 onward. We have previously found that most stromal cells in confluent cultures were stained by monoclonal antibodies directed against smooth muscle- specific actin isoforms. The present study was carried out to evaluate the time course of alpha-SM-positive stromal cells and to search for other cytoskeletal proteins specific for smooth muscle cells. It was found that the expression of alpha-SM in stromal cells was time dependent. Most of the adherent spindle-shaped, vimentin-positive stromal cells observed during the first 2 weeks of culture were alpha- SM negative. On the contrary, from week 3 to week 7, most interdigitated stromal cells contained stress fibers whose backbone was made of alpha-SM-positive microfilaments. In addition, in confluent cultures, other proteins specific for smooth muscle were detected: metavinculin, h-caldesmon, smooth muscle myosin heavy chains, and calponin. This study confirms the similarity between stromal cells and smooth muscle cells. Moreover, our results reveal that cells in vivo with the phenotype closest to that of stromal cells are immature fetal smooth muscle cells and subendothelial intimal smooth muscle cells; a cell subset with limited development following birth but extensively recruited in atherosclerotic lesions. Stromal cells very probably derive from mesenchymal cells that differentiate along this distinctive vascular smooth muscle cell pathway. In humans, this differentiation seems crucial for the maintenance of granulomonopoiesis. These in vitro studies were completed by examination of trephine bone marrow biopsies from adults without hematologic abnormalities. These studies revealed the presence of alpha-SM-positive cells at diverse locations: vascular smooth muscle cells in the media of arteries and arterioles, pericytes lining capillaries, myoid cells lining sinuses at the abluminal side of endothelial cells or found within the hematopoietic logettes, and endosteal cells lining bone trabeculae. More or less mature cells of the granulocytic series were in intimate contact with the thin cytoplasmic extensions of myoid cells. Myoid cells may be the in vivo counterpart of stromal cells with the above-described vascular smooth muscle phenotype.

scholarly journals Induction of cyclooxygenase-2 in rat vascular smooth muscle cells in vitro and in vivo.

1994 ◽  
Vol 269 (11) ◽  
pp. 8504-8509
Author(s):  
K.A. Pritchard ◽  
M.K. O'Banion ◽  
J.M. Miano ◽  
N. Vlasic ◽  
U.G. Bhatia ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cyclooxygenase 2

Angiotensin II modulates frizzled-2 receptor expression in rat vascular smooth muscle cells

2005 ◽  
Vol 108 (6) ◽  
pp. 523-530 ◽  
Author(s):  
Giovanna CASTOLDI ◽  
Serena REDAELLI ◽  
Willy M. M. van de GREEF ◽  
Cira R. T. di GIOIA ◽  
Giuseppe BUSCA ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Angiotensin Ii ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Ang Ii ◽  
Aortic Smooth Muscle

Ang II (angiotensin II) has multiple effects on vascular smooth muscle cells through the modulation of different classes of genes. Using the mRNA differential-display method to investigate gene expression in rat aortic smooth muscle cells in culture in response to 3 h of Ang II stimulation, we observed that Ang II down-regulated the expression of a member of the family of transmembrane receptors for Wnt proteins that was identified as Fzd2 [Fzd (frizzled)-2 receptor]. Fzds are a class of highly conserved genes playing a fundamental role in the developmental processes. In vitro, time course experiments demonstrated that Ang II induced a significant increase (P<0.05) in Fzd2 expression after 30 min, whereas it caused a significant decrease (P<0.05) in Fzd2 expression at 3 h. A similar rapid up-regulation after Ang II stimulation for 30 min was evident for TGFβ1 (transforming growth factor β1; P<0.05). To investigate whether Ang II also modulated Fzd2 expression in vivo, exogenous Ang II was administered to Sprague–Dawley rats (200 ng·kg−1 of body weight·min−1; subcutaneously) for 1 and 4 weeks. Control rats received normal saline. After treatment, systolic blood pressure was significantly higher (P<0.01), whereas plasma renin activity was suppressed (P<0.01) in Ang II- compared with the saline-treated rats. Ang II administration for 1 week did not modify Fzd2 expression in aorta of Ang II-treated rats, whereas Ang II administration for 4 weeks increased Fzd2 mRNA expression (P<0.05) in the tunica media of the aorta, resulting in a positive immunostaining for fibronectin at this time point. In conclusion, our data demonstrate that Ang II modulates Fzd2 expression in aortic smooth muscle cells both in vitro and in vivo.

scholarly journals SIRT1 and FOXO Mediate Contractile Differentiation of Vascular Smooth Muscle Cells under Cyclic Stretch

2015 ◽  
Vol 37 (5) ◽  
pp. 1817-1829 ◽  
Author(s):  
Kai Huang ◽  
Zhi-Qiang Yan ◽  
Dan Zhao ◽  
Si-Guo Chen ◽  
Li-Zhi Gao ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Cyclic Stretch ◽  
Underlying Mechanisms

Background/Aims: Physiological mechanical stretch in vivo helps to maintain the quiescent contractile differentiation of vascular smooth muscle cells (VSMCs), but the underlying mechanisms are still unclear. Here, we investigated the effects of SIRT1 in VSMC differentiation in response to mechanical cyclic stretch. Methods and Results: Rat VSMCs were subjected to 10%-1.25Hz-cyclic stretch in vitro using a FX-4000T system. The data indicated that the expression of contractile markers, including α-actin, calponin and SM22α, was significantly enhanced in VSMCs that were subjected to cyclic stretch compared to the static controls. The expression of SIRT1 and FOXO3a was increased by the stretch, but the expression of FOXO4 was decreased. Decreasing SIRT1 by siRNA transfection attenuated the stretch-induced expression of contractile VSMC markers and FOXO3a. Furthermore, increasing SIRT1 by either treatment with activator resveratrol or transfection with a plasmid to induce overexpression increased the expression of FOXO3a and contractile markers, and decreased the expression of FOXO4 in VSMCs. Similar trends were observed in VSMCs of SIRT1 (+/-) knockout mice. The overexpression of FOXO3a promoted the expression of contractile markers in VSMCs, while the overexpression of FOXO4 demonstrated the opposite effect. Conclusion: Our results indicated that physiological cyclic stretch promotes the contractile differentiation of VSMCs via the SIRT1/FOXO pathways and thus contributes to maintaining vascular homeostasis.

Sign in / Sign up

Export Citation Format

Share Document