Conditional differentiation of heart- and smooth muscle-derived cells transformed by a temperature-sensitive mutant of SV40 T antigen

1996 ◽  
Vol 109 (2) ◽  
pp. 397-407
Author(s):  
L. Jahn ◽  
J. Sadoshima ◽  
A. Greene ◽  
C. Parker ◽  
K.G. Morgan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Smooth Muscle ◽  
Cell Lines ◽  
Muscle Cell ◽  
Muscle Cells ◽  
Cell Types ◽  
T Antigen ◽  
Temperature Sensitive ◽  
C Cells ◽  
Sv40 T Antigen

To create muscle cell lines that conditionally differentiate in vitro we introduced a temperature-sensitive SV40 T antigen by retroviral infection into rat aortic smooth muscle cells (SMCs) and neonatal heart-derived cells. After G418 selection cell lines isolated were characterized at permissive (33 degrees C) and non-permissive (39 degrees C) temperatures. [3H]Thymidine uptake showed tht progression through the cell cycle is greatly reduced at 39 degrees C. Cytoskeletal proteins, such as actins and vimentin did not change significantly after temperature shift, while the number of desmin-positive SMCs significantly increased when cells were switched to 39 degrees C. Heart-derived muscle cells showed sarcomeric myosin heavy chain reactivity only when grown at 39 degrees C. After thrombin stimulation intracellular calcium in both cell types increased severalfold in 39 degrees C-cells but not in 33 degrees C-cells. Whole cell patch-clamp recordings of SMCs and heart-derived cells revealed a strong increase in nicardipine-sensitive Ca2+ current when cells were switched to 39 degrees C. Nicardipine-insensitive Ca2+ current also increased in both cell types at the non-permissive temperature. Na+ current in SMCs was large at 33 degrees C and small or not detectable at 39 degrees C and absent in heart-derived cells. Using a cDNA probe specific for the alpha 1 subunit of the dihydropyridine-sensitive Ca2+ channel we demonstrate a temperature-sensitive expression of the dihydropyridine receptor mRNA in smooth muscle-derived cells but not in heart-derived H10 cells. Our results suggest that upon downregulation of SV40 T antigen these cells become quiescent and exhibit a more differentiated phenotype. These cell lines may provide a useful tool to investigate ion channel- and receptor signal transduction, as well as cell cycle control in smooth and possibly cardiac muscle cell differentiation.

Abstract 465: Deciphering the Genetic Regulation of ADAMTS7 , a Novel Locus for Coronary Artery Disease

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Kristy Ou ◽  
Robert C Bauer ◽  
Xuan Zhang ◽  
Jian Cui ◽  
Daniel J Rader ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Cell Lines ◽  
Genetic Regulation ◽  
Muscle Cells ◽  
Cell Types ◽  
Artery Disease ◽  
Genomic Regions

Recent genome-wide association studies (GWAS) have identified an association between the ADAMTS7 locus and coronary artery disease (CAD) in humans. While ADAMTS7 is proposed to play a role in vascular smooth muscle cell (VSMC) migration and neointimal formation, the molecular regulation of human ADAMTS7 gene expression has not yet been explored. We assessed ADAMTS7 expression levels in primary mouse aortic smooth muscle cells (mAoSMC) as well as primary human coronary and human pulmonary artery smooth muscle cells (hCASMC, hPASMC) in response to treatment with various stimulatory agents. No differences in ADAMTS7 expression were observed upon treatment with PDGF, angiotensin II, and nicotine in any of the cell lines tested. However, TNFα upregulated ADAMTS7 by 4-fold in mAoSMC but not in human VSMCs while H 2 O 2 upregulated ADAMTS7 by 4-fold in hCASMC but not mAoSMCs. No agents modulated expression in hPASMC. Basal levels of ADAMTS7 varied among different VSMC lines; hCASMC had 2-fold greater levels of ADAMTS7 when compared to hPASMC and hAoSMC. These data demonstrate that ADAMTS7 is differentially regulated not only across different species, but also among different VSMC types, underscoring the complex genetic regulation of ADAMTS7 . In an attempt to elucidate important regulatory genomic regions controlling ADAMTS7 expression, we utilized data from the ENCODE project to identify regions surrounding ADAMTS7 that are enriched for regulatory domains, e.g. DNase hypsersensitivity (DHS) and H3K27 acetylation, in relevant cell types. We then overlayed data from CARDIoGRAM and C4D CAD GWAS to look for CAD-associated SNPs in these potential enhancers. Ultimately we selected 5 regions of interest (e.g., rs5029904 lies in region with increased H3K27 acetylation in ENCODE layered 7 cell lines, DHS peaks in serum fed and starved hAoSMCs, binding peaks for transcription factors via ENCODE ChIP-Seq experiments) for further studies in luciferase reporter assays multiple cell types to look for tissue specific expression mediated by these genomic regions. GWAS variants in these domains may affect the transcriptional regulation of ADAMTS7 , thus providing insight into the role for ADAMTS7 in human atherosclerosis.

scholarly journals Regulation of p16CDKN2 expression and its implications for cell immortalization and senescence.

1996 ◽  
Vol 16 (3) ◽  
pp. 859-867 ◽  
Author(s):  
E Hara ◽  
R Smith ◽  
D Parry ◽  
H Tahara ◽  
S Stone ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
Human Fibroblasts ◽  
Simian Virus 40 ◽  
Simian Virus ◽  
T Antigen ◽  
Temperature Sensitive ◽  
The Status ◽  
Population Doublings

p16CDKN2 specifically binds to and inhibits the cyclin-dependent kinases CDK4 and CDK6, which function as regulators of cell cycle progression in G1 by contributing to the phosphorylation of the retinoblastoma protein (pRB). Human cell lines lacking functional pRB contain high levels of p16 RNA and protein, suggesting a negative feedback loop by which pRB might regulate p16 expression in late G1. By a combination of nuclear run-on assays and promoter analyses in human fibroblasts expressing a temperature-sensitive simian virus 40 T antigen, we show that p16 transcription is affected by the status of pRB and define a region in the p16 promoter that is required for this response. However, the effect is not sufficient to account for the differences in p16 RNA levels between pRB-positive and -negative cells. Moreover, p16 RNA is extremely stable, and the levels do not change appreciably during the cell cycle. Primary human fibroblasts express very low levels of p16, but the RNA and protein accumulate in late-passage, senescent cells. The apparent overexpression of p16 in pRB-negative cell lines is therefore caused by at least two factors: loss of repression by pRB and an increase in the number of population doublings.

Telokin expression is mediated by a smooth muscle cell-specific promoter

1996 ◽  
Vol 270 (6) ◽  
pp. C1656-C1665 ◽  
Author(s):  
B. P. Herring ◽  
A. F. Smith
Keyword(s):  
Smooth Muscle ◽  
Transgenic Mice ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Antigen Expression ◽  
Muscle Cells ◽  
T Antigen ◽  
Sv40 Large T Antigen ◽  
Muscle Tissues

The carboxy terminus of the smooth muscle myosin light chain kinase (smMLCK) is expressed as an independent protein, telokin. Western and Northern blotting analyses demonstrated that telokin protein and mRNA are expressed at high levels only in adult and embryonic smooth muscle tissues and cells. In vitro transfection assays in A10 smooth muscle cells identified a functional promoter located in an intron in the 3' region of the smMLCK gene that directs the smooth muscle cell-specific transcription of telokin. To test the cell specificity of the telokin promoter in vivo, transgenic mice were generated in which the telokin promoter was used to drive expression of SV40 large T-antigen. Expression of T-antigen in the transgenic mice paralleled that of the endogenous telokin gene. High levels of T-antigen expression were observed in smooth muscle tissues of the digestive, urinary, and reproductive tracts, with lower levels of expression in airway and vascular smooth muscle. Expression was restricted to smooth muscle cells, with no expression detected in any other cell type.

Involvement of Cyclooxygenase- and Lipoxygenase-Mediated Conversion of Arachidonic Acid in Controlling Human Vascular Smooth Muscle Cell Proliferation

1990 ◽  
Vol 63 (02) ◽  
pp. 291-297 ◽  
Author(s):  
Herm-Jan M Brinkman ◽  
Marijke F van Buul-Worteiboer ◽  
Jan A van Mourik
Keyword(s):  
Cell Proliferation ◽  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Muscle Cells ◽  
Smooth Muscle Cell Proliferation

SummaryWe observed that the growth of human umbilical arterysmooth muscle cells was inhibited by the phospholipase A2 inhibitors p-bromophenacylbromide and mepacrine. Thesefindings suggest that fatty acid metabolism might be integrated in the control mechanism of vascular smooth muscle cell proliferation. To identify eicosanoids possibly involved in this process, we studied both the metabolism of arachidonic acid of these cells in more detail and the effect of certain arachidonic acid metabolites on smooth muscle cells growth. We found no evidence for the conversion of arachidonic acid via the lipoxygenase pathway. In contrast, arachidonic acid was rapidly converted via the cyclooxy-genase pathway. The following metabolites were identified: prostaglandin E2 (PGE2), 6-keto-prostaglandin F1α (6-k-PGF1α), prostaglandin F2α (PGF2α), 12-hydroxyheptadecatrienoic acid (12-HHT) and 11-hydroxyeicosatetetraenoic acid (11-HETE). PGE2 was the major metabolite detected. Arachidonic acid metabolites were only found in the culture medium, not in the cell. After synthesis, 11-HETE was cleared from the culture medium. We have previously reported that PGE2 inhibits the serum-induced [3H]-thymidine incorporation of growth-arrested human umbilical artery smooth muscle cells. Here we show that also 11-HETEexerts this inhibitory property. Thus, our data suggeststhat human umbilical artery smooth muscle cells convert arachidonic acid only via the cyclooxygenase pathway. Certain metabolites produced by this pathway, including PGE2 and 11-HETE, may inhibit vascular smooth muscle cell proliferation.

Ethylisopropylamiloride-sensitive pH control mechanisms modulate vascular smooth muscle cell growth

1991 ◽  
Vol 260 (3) ◽  
pp. C581-C588 ◽  
Author(s):  
A. Bobik ◽  
A. Grooms ◽  
P. J. Little ◽  
E. J. Cragoe ◽  
S. Grinpukel
Keyword(s):  
Cell Cycle ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Mitotic Cell ◽  
Ph Control ◽  
S Phase ◽  
Control Mechanisms ◽  
Aortic Smooth Muscle ◽  
Exchange Activity

The reported effects of alterations in Na-H exchange activity on mitogenesis are variable and appear dependent on the cell type examined. We examined the effects of reductions in ethylisopropylamiloride (EIPA)-sensitive pH-regulating mechanisms including Na-H exchange and alterations in intracellular pH (pHi) on the growth characteristics of rat aortic smooth muscle cells (RASM) cultured in serum-containing bicarbonate-buffered medium. Exposure of RASM replicating in bicarbonate-containing medium to the Na-H exchange inhibitors EIPA, dimethylamiloride (DMA), or amiloride (A) attenuated their replication rate. The order of potency of the inhibitors (EIPA greater than DMA much greater than A) was similar to their documented effects on Na-H exchange activity and to their order of potency for inhibiting recovery from CO2-induced acidosis in these cells. Reductions in pHi induced by lowering extracellular pH also attenuated the incorporation of [3H]-thymidine into DNA, while increases in pHi were associated with an acceleration in the rate of incorporation of [3H]thymidine into DNA. The effects of the Na-H exchange inhibitors on RASM replication were due to a reduction in the ability of the smooth muscle cells to enter the S phase of the mitotic cell cycle. This appeared predominantly the consequence of effects late within the G1 phase of the cell cycle. Concentrations of EIPA that markedly reduced the ability of RASM to enter S phase and to replicate also attenuated the increase in protein synthesis occurring 6-8 h after exposure to serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document