scholarly journals MYOSLIDIs a Novel Serum Response Factor–Dependent Long Noncoding RNA That Amplifies the Vascular Smooth Muscle Differentiation Program

2016 ◽  
Vol 36 (10) ◽  
pp. 2088-2099 ◽  
Author(s):  
Jinjing Zhao ◽  
Wei Zhang ◽  
Mingyan Lin ◽  
Wen Wu ◽  
Pengtao Jiang ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Serum Response Factor ◽  
Muscle Differentiation ◽  
Response Factor ◽  
Smooth Muscle Differentiation ◽  
Serum Response

A role for serum response factor in coronary smooth muscle differentiation from proepicardial cells

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2053-2062 ◽  
Author(s):  
T.E. Landerholm ◽  
X.R. Dong ◽  
J. Lu ◽  
N.S. Belaguli ◽  
R.J. Schwartz ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Serum Response Factor ◽  
Muscle Differentiation ◽  
Dominant Negative ◽  
Response Factor ◽  
Coronary Smooth Muscle ◽  
Epicardial Cells ◽  
Smooth Muscle Differentiation ◽  
Mesenchymal Transformation ◽  
Serum Response

Coronary artery smooth muscle (SM) cells originate from proepicardial cells that migrate over the surface of the heart, undergo epithelial to mesenchymal transformation and invade the subepicardial and cardiac matrix. Prior to contact with the heart, proepicardial cells exhibit no expression of smooth muscle markers including SMalphaactin, SM22alpha, calponin, SMgammaactin or SM-myosin heavy chain detectable by RT-PCR or by immunostaining. To identify factors required for coronary smooth muscle differentiation, we excised proepicardial cells from Hamburger-Hamilton stage-17 quail embryos and examined them ex vivo. Proepicardial cells initially formed an epithelial colony that was uniformly positive for cytokeratin, an epicardial marker. Transcripts for flk-1, Nkx 2.5, GATA4 or smooth muscle markers were undetectable, indicating an absence of endothelial, myocardial or preformed smooth muscle cells. By 24 hours, cytokeratin-positive cells became SMalphaactin-positive. Moreover, serum response factor, undetectable in freshly isolated proepicardial cells, became strongly expressed in virtually all epicardial cells. By 72 hours, a subset of epicardial cells exhibited a rearrangement of cytoskeletal actin, focal adhesion formation and acquisition of a motile phenotype. Coordinately with mesenchymal transformation, calponin, SM22alpha and SMgammaactin became expressed. By 5–10 days, SM-myosin heavy chain mRNA was found, by which time nearly all cells had become mesenchymal. RT-PCR showed that large increases in serum response factor expression coincide with smooth muscle differentiation in vitro. Two different dominant-negative serum response factor constructs prevented the appearance of calponin-, SM22alpha- and SMgammaactin-positive cells. By contrast, dominant-negative serum response factor did not block mesenchymal transformation nor significantly reduce the number of cytokeratin-positive cells. These results indicate that the stepwise differentiation of coronary smooth muscle cells from proepicardial cells requires transcriptionally active serum response factor.

scholarly journals Four isoforms of serum response factor that increase or inhibit smooth-muscle-specific promoter activity

2000 ◽  
Vol 345 (3) ◽  
pp. 445-451 ◽  
Author(s):  
Paul R. KEMP ◽  
James C. METCALFE
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Serum Response Factor ◽  
Muscle Cells ◽  
Dominant Negative ◽  
C2c12 Cells ◽  
Specific Gene ◽  
Response Factor ◽  
Transactivation Domain ◽  
Serum Response

Serum response factor (SRF) is a key transcriptional activator of the c-fos gene and of muscle-specific gene expression. We have identified four forms of the SRF coding sequence, SRF-L (the previously identified form), SRF-M, SRF-S and SRF-I, that are produced by alternative splicing. The new forms of SRF lack regions of the C-terminal transactivation domain by splicing out of exon 5 (SRF-M), exons 4 and 5 (SRF-S) and exons 3, 4 and 5 (SRF-I). SRF-M is expressed at similar levels to SRF-L in differentiated vascular smooth-muscle cells and skeletal-muscle cells, whereas SRF-L is the predominant form in many other tissues. SRF-S expression is restricted to vascular smooth muscle and SRF-I expression is restricted to the embryo. Transfection of SRF-L and SRF-M into C2C12 cells showed that both forms are transactivators of the promoter of the smooth-muscle-specific gene SM22α, whereas SRF-I acted as a dominant negative form of SRF.

scholarly journals MicroRNA-125b Affects Vascular Smooth Muscle Cell Function by Targeting Serum Response Factor

2018 ◽  
Vol 46 (4) ◽  
pp. 1566-1580 ◽  
Author(s):  
Zhibo Chen ◽  
Mian Wang ◽  
Kai Huang ◽  
Qiong He ◽  
Honghao Li ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Serum Response Factor ◽  
Cell Function ◽  
Luciferase Reporter ◽  
Response Factor ◽  
Neointimal Formation ◽  
Migration Flow ◽  
Expression Levels ◽  
Serum Response

Background/Aims: Increasing evidence links microRNAs to the pathogenesis of peripheral vascular disease. We recently found microRNA-125b (miR-125b) to be one of the most significantly down‑regulated microRNAs in human arteries with arteriosclerosis obliterans (ASO) of the lower extremities. However, its function in the process of ASO remains unclear. This study aimed to investigate the expression, regulatory mechanisms, and functions of miR-125b in the process of ASO. Methods: Using the tissue explants adherent method, vascular smooth muscle cells (VSMCs) were prepared for this study. A rat carotid artery balloon injury model was constructed to simulate the development of vascular neointima, and a lentiviral transduction system was used to overexpress serum response factor (SRF) or miR-125b. Quantitative real‑time PCR (qRT‑PCR) was used to detect the expression levels of miR‑125b and SRF mRNA. Western blotting was performed to determine the expression levels of SRF and Ki67. In situ hybridization analysis was used to analyze the location and expression levels of miR-125b. CCK-8 and EdU assays were used to assess cell proliferation, and transwell and wound closure assays were performed to measure cell migration. Flow cytometry was used to evaluate cell apoptosis, and a dual-luciferase reporter assay was conducted to examine the effects of miR‑125b on SRF. Immunohistochemistry and immunofluorescence analyses were performed to analyze the location and expression levels of SRF and Ki67. Results: miR-125b expression was decreased in ASO arteries and platelet-derived growth factor (PDGF)-BB-stimulated VSMCs. miR-125b suppressed VSMC proliferation and migration but promoted VSMC apoptosis. SRF was determined to be a direct target of miR-125b. Exogenous miR-125b expression modulated SRF expression and inhibited vascular neointimal formation in balloon-injured rat carotid arteries. Conclusions: These findings demonstrate a specific role of the miR-125b/SRF pathway in regulating VSMC function and suggest that modulating miR-125b levels might be a novel approach for treating ASO.

scholarly journals Smooth Muscle Cell–Enriched Long Noncoding RNA Regulates Cell Plasticity and Atherosclerosis by Interacting With Serum Response Factor

2021 ◽  
Author(s):  
Huaner Ni ◽  
Stefan Haemmig ◽  
Yihuan Deng ◽  
Jingshu Chen ◽  
Viorel Simion ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Noncoding Rna ◽  
Serum Response Factor ◽  
Mass Spectrometry Analysis ◽  
Response Factor ◽  
Dependent Manner ◽  
Serum Response

Objective: Vascular smooth muscle cell (VSMC) plasticity plays a critical role in the development of atherosclerosis. Long noncoding RNAs (lncRNAs) are emerging as important regulators in the vessel wall and impact cellular function through diverse interactors. However, the role of lncRNAs in regulating VSMCs plasticity and atherosclerosis remains unclear. Approach and Results: We identified a VSMC-enriched lncRNA cardiac mesoderm enhancer-associated noncoding RNA (CARMN) that is dynamically regulated with progression of atherosclerosis. In both mouse and human atherosclerotic plaques, CARMN colocalized with VSMCs and was expressed in the nucleus. Knockdown of CARMN using antisense oligonucleotides in Ldlr −/− mice significantly reduced atherosclerotic lesion formation by 38% and suppressed VSMCs proliferation by 45% without affecting apoptosis. In vitro CARMN gain- and loss-of-function studies verified effects on VSMC proliferation, migration, and differentiation. TGF-β1 (transforming growth factor-beta) induced CARMN expression in a Smad2/3-dependent manner. CARMN regulated VSMC plasticity independent of the miR143/145 cluster, which is located in close proximity to the CARMN locus. Mechanistically, lncRNA pulldown in combination with mass spectrometry analysis showed that the nuclear-localized CARMN interacted with SRF (serum response factor) through a specific 600–1197 nucleotide domain. CARMN enhanced SRF occupancy on the promoter regions of its downstream VSMC targets. Finally, knockdown of SRF abolished the regulatory role of CARMN in VSMC plasticity. Conclusions: The lncRNA CARMN is a critical regulator of VSMC plasticity and atherosclerosis. These findings highlight the role of a lncRNA in SRF-dependent signaling and provide implications for a range of chronic vascular occlusive disease states.

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