scholarly journals Involvement of DHX9/YB-1 complex induced alternative splicing of Krüppel-like factor 5 mRNA in phenotypic transformation of vascular smooth muscle cells

2019 ◽  
Vol 317 (2) ◽  
pp. C262-C269
Author(s):  
Wei Huan ◽  
Jing Zhang ◽  
Yingke Li ◽  
Kangkang Zhi

Phenotypic transformation of vascular smooth muscle cells is a key phenomenon in the development of aortic dissection disease. However, the molecular mechanisms underlying this phenomenon have not been fully understood. We used β-BAPN combined with ANG II treatment to establish a disease model of acute aortic dissection (AAD) in mice. We first examined the gene expression profile of aortic tissue in mice with AAD using a gene chip, followed by confirmation of DExH-box helicase 9 (DHX9) expression using RT-PCR, Western blot, and immunofluorescence analysis. We further developed vascular smooth muscle cell-specific DHX9 conditional knockout mice and conducted differential and functional analysis of gene expression and alternative splicing in mouse vascular smooth muscle cells. Finally, we examined the involvement of DHX9 in Krüppel-like factor 5 ( KLF5) mRNA alternative splicing. Our study reported a significant decrease in the expression of DHX9 in the vascular smooth muscle cells (VSMCs) of mice with AAD. The smooth muscle cell-specific knockout of DHX9 exacerbated the development of AAD and altered the transcriptional level expression of many smooth muscle cell phenotype-related genes. Finally, we reported that DHX9 may induce alternative splicing of KLF5 mRNA by bridging YB-1. These results together suggested a new pathogenic mechanism underlying the development of AAD, and future research of this mechanism may help identify effective therapeutic intervention for AAD.

2018 ◽  
Author(s):  
Thomas R. Whitesell ◽  
Paul Chrystal ◽  
Jae-Ryeon Ryu ◽  
Nicole Munsie ◽  
Ann Grosse ◽  
...  

AbstractDespite the critical role of vascular mural cells (smooth muscle cells and pericytes) in supporting the endothelium of blood vessels, we know little of their early morphogenesis and differentiation. foxc1b:EGFP expressing cells in zebrafish associate with the vascular endothelium (kdrl) and co-express a smooth muscle marker (acta2), but not a pericyte marker (pdgfrβ). The expression of foxc1b in early peri-endothelial mesenchymal cells allows us to follow the morphogenesis of mesenchyme into acta2 expressing vascular smooth muscle cells. We show that mural cells expressing different markers associate with vessels of different diameters, depending on their embryonic location and developmental timing, suggesting marker expression is predictive of functional differences. We identify gene expression signatures for an enriched vascular smooth muscle cell population (foxc1b + acta2) and all smooth muscle (acta2) using fluorescence-activated cell sorting and RNA-Seq. Finally, we demonstrate that progressive loss of foxc1a/foxc1b results in decreased smooth muscle cell coverage. Together, our data highlight the early cellular dynamics and transcriptome profiles of smooth muscle cells in vivo, using foxc1b as a unique tool to probe vascular smooth muscle cell differentiation.Summary StatementTracing the morphogenesis and transcriptome of early vascular smooth muscle cells using foxc1b


2000 ◽  
Vol 113 (11) ◽  
pp. 2055-2064
Author(s):  
E. Stringa ◽  
V. Knauper ◽  
G. Murphy ◽  
J. Gavrilovic

Cell migration is a key event in many biological processes and depends on signals from both extracellular matrix and soluble motogenic factors. During atherosclerotic plaque development, vascular smooth muscle cells migrate from the tunica media to the intima through a basement membrane and interstitial collagenous matrix and proliferate to form a neointima. Matrix metalloproteinases have previously been implicated in neointimal formation and in this study smooth muscle cell adhesion and migration on degraded collagen have been evaluated. Vascular smooth muscle cells adhered to native intact collagen type I and to its first degradation by-product, 3/4 fragment (generated by collagenase-3 cleavage), unwound at 35 degrees C to mimic physiological conditions. PDGF-BB pre-treatment induced a fourfold stimulation of smooth muscle cell motility on the collagen 3/4 fragment whereas no increase in smooth muscle cell motility on collagen type I was observed. Cell migration on collagen type I was mediated by alpha2 integrin, whereas PDGF-BB-stimulated migration on the 3/4 collagen fragment was dependent on alphavbeta3 integrin. alphavbeta3 integrin was organised in clusters concentrated at the leading and trailing edges of the cells and was only expressed when cells were exposed to the 3/4 collagen fragment. Tyrphostin A9, an inhibitor of PDGF receptor-beta tyrosine kinase activity, resulted in complete abolition of migration of PDGF-BB treated cells on collagen type I and 3/4 fragment. These results strongly support the hypothesis that the cellular migratory response to soluble motogens can be regulated by proteolytic modification of the extracellular matrix.


1990 ◽  
Vol 258 (1) ◽  
pp. C46-C53 ◽  
Author(s):  
R. Zaragoza ◽  
K. M. Battle-Tracy ◽  
N. E. Owen

Vascular smooth muscle cell proliferation has been shown to be an important factor in atheromatous plaque formation, hypertrophy associated with essential hypertension, and failure of balloon angioplasty procedures. Investigators have shown that a number of different agents stimulate vascular smooth muscle cell proliferation, including epidermal growth factor, platelet-derived growth factor, angiotensin II, and catecholamines. Previously, we have demonstrated that these agents also cause immediate changes in ion transport and second messenger generation in vascular smooth muscle cells. We have proposed that these immediate changes may be linked to each other and to cell proliferation. In contrast to the many agents that have been shown to stimulate vascular smooth muscle cell proliferation, only a few agents (e.g., heparin sodium or transforming growth factor-beta) have been shown to inhibit vascular smooth muscle cell proliferation. In the present study we have investigated whether heparin inhibits serum- or growth factor-stimulated changes in ion transport and second messenger generation in vascular smooth muscle cells. We found that heparin inhibits serum- or growth factor-stimulated Na(+)-H+ exchange in a concentration-dependent manner that is not dependent on the ability of heparin to function as an anticoagulant agent. In addition, other glycosaminoglycans were not found to be inhibitory, and the inhibitory effects of heparin were discovered to be limited to vascular smooth muscle cells. Heparin does not appear to be acting by binding to growth factors, or by directly inhibiting the Na(+)-H+ exchange protein. However, heparin did inhibit serum- or growth factor-stimulated inositol trisphosphate release and calcium mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)


2013 ◽  
Vol 305 (9) ◽  
pp. H1281-H1287 ◽  
Author(s):  
Nancy L. Sehgel ◽  
Yi Zhu ◽  
Zhe Sun ◽  
Jerome P. Trzeciakowski ◽  
Zhongkui Hong ◽  
...  

Increased vascular stiffness is fundamental to hypertension, and its complications, including atherosclerosis, suggest that therapy should also be directed at vascular stiffness, rather than just the regulation of peripheral vascular resistance. It is currently held that the underlying mechanisms of vascular stiffness in hypertension only involve the extracellular matrix and endothelium. We hypothesized that increased large-artery stiffness in hypertension is partly due to intrinsic mechanical properties of vascular smooth muscle cells. After confirming increased arterial pressure and aortic stiffness in spontaneously hypertensive rats, we found increased elastic stiffness of aortic smooth muscle cells of spontaneously hypertensive rats compared with Wistar-Kyoto normotensive controls using both an engineered aortic tissue model and atomic force microscopy nanoindentation. Additionally, we observed different temporal oscillations in the stiffness of vascular smooth muscle cells derived from hypertensive and control rats, suggesting that a dynamic component to cellular elastic stiffness is altered in hypertension. Treatment with inhibitors of vascular smooth muscle cell cytoskeletal proteins reduced vascular smooth muscle cell stiffness from hypertensive and control rats, suggesting their participation in the mechanism. This is the first study demonstrating that stiffness of individual vascular smooth muscle cells mediates vascular stiffness in hypertension, a novel concept, which may elucidate new therapies for hypertension and for vascular stiffness.


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