scholarly journals Cyclic mechanical stretch up-regulates hepatoma-derived growth factor expression in cultured rat aortic smooth muscle cells

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Ying-Hsien Kao ◽  
Po-Han Chen ◽  
Cheuk-Kwan Sun ◽  
Yo-Chen Chang ◽  
Yu-Chun Lin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Constitutive Expression ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Morphological Observation ◽  
Mechanical Stimuli ◽  
Vascular Walls ◽  
Tnf Α

Hepatoma-derived growth factor (HDGF) is a potent mitogen for vascular smooth muscle cells (SMCs) during embryogenesis and injury repair of vessel walls. Whether mechanical stimuli modulate HDGF expression remains unknown. The present study aimed at investigating whether cyclic mechanical stretch plays a regulatory role in HDGF expression and regenerative cytokine production in aortic SMCs. A SMC cell line was grown on a silicone-based elastomer chamber with extracellular matrix coatings (either type I collagen or fibronectin) and received cyclic and uniaxial mechanical stretches with 10% deformation at frequency 1 Hz. Morphological observation showed that fibronectin coating provided better cell adhesion and spreading and that consecutive 6 h of cyclic mechanical stretch remarkably induced reorientation and realignment of SMCs. Western blotting detection demonstrated that continuous mechanical stimuli elicited up-regulation of HDGF and proliferative cell nuclear antigen, a cell proliferative marker. Signal kinetic profiling study indicated that cyclic mechanical stretch induced signaling activity in RhoA/ROCK and PI3K/Akt cascades. Kinase inhibition study further showed that blockade of PI3K activity suppressed the stretch-induced tumor necrosis factor-α (TNF-α), whereas RhoA/ROCK inhibition significantly blunted the interleukin-6 (IL-6) production and HDGF overexpression. Moreover, siRNA-mediated HDGF gene silencing significantly suppressed constitutive expression of IL-6, but not TNF-α, in SMCs. These findings support the role of HDGF in maintaining vascular expression of IL-6, which has been regarded a crucial regenerative factor for acute vascular injury. In conclusion, cyclic mechanical stretch may maintain constitutive expression of HDGF in vascular walls and be regarded an important biophysical regulator in vascular regeneration.

Mechanical stretch regulates cell survival in human bladder smooth muscle cells in vitro

2002 ◽  
Vol 283 (6) ◽  
pp. F1192-F1199 ◽  
Author(s):  
David J. Galvin ◽  
R. William G. Watson ◽  
James I. Gillespie ◽  
Hugh Brady ◽  
John M. Fitzpatrick
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Bladder Smooth Muscle ◽  
Human Bladder ◽  
Cell Hypertrophy ◽  
Growth Factor Production

Our understanding of the pathophysiology of the overactive bladder is poor. It has been proposed that localized contractions result in the abnormal stretching of bladder smooth muscle. We hypothesize that stretch regulates the cellular processes that determine tissue size. The purpose of this study was to investigate the effect of stretch on apoptosis, proliferation, cell hypertrophy, and growth factor production in human bladder smooth muscle cells in vitro. Normal human detrusor muscle was obtained from patients undergoing radical cystectomy for invasive bladder cancer, and primary cultures were established. Cells were mechanically stretched on flexible plates at a range of pressures and times. Apoptosis was assessed by propidium iodide incorporation and flow cytometry. Radiolabeled thymidine and amino acid incorporation were used to assess proliferation and cell hypertrophy. ELISA and RT-PCR were used to assess growth factor production. Mechanical stretch inhibits apoptosis in a time- and dose-dependent manner and was associated with increases in the antiapoptotic proteins heat shock protein-70 and cIAP-1. Stretch also increases smooth muscle cell proliferation and hypertrophy, but hypertrophy is the more dominant response. These changes were associated with increases in IGF-1 and basic FGF and a decrease in transforming growth factor-β1. Mechanical stretch regulates apoptosis, proliferation, and cell hypertrophy in human bladder smooth muscle cells.

scholarly journals Mechanical stretch is a highly selective regulator of gene expression in human bladder smooth muscle cells

2004 ◽  
Vol 20 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Rosalyn M. Adam ◽  
Samuel H. Eaton ◽  
Carlos Estrada ◽  
Ashish Nimgaonkar ◽  
Shu-Ching Shih ◽  
...  
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Ex Vivo ◽  
Muscle Cells ◽  
Mechanical Stimuli ◽  
Bladder Smooth Muscle ◽  
Human Bladder ◽  
Cox 2

Application of mechanical stimuli has been shown to alter gene expression in bladder smooth muscle cells (SMC). To date, only a limited number of “stretch-responsive” genes in this cell type have been reported. We employed oligonucleotide arrays to identify stretch-sensitive genes in primary culture human bladder SMC subjected to repetitive mechanical stimulation for 4 h. Differential gene expression between stretched and nonstretched cells was assessed using Significance Analysis of Microarrays (SAM). Expression of 20 out of 11,731 expressed genes (∼0.17%) was altered >2-fold following stretch, with 19 genes induced and one gene (FGF-9) repressed. Using real-time RT-PCR, we tested independently the responsiveness of 15 genes to stretch and to platelet-derived growth factor-BB (PDGF-BB), another hypertrophic stimulus for bladder SMC. In response to both stimuli, expression of 13 genes increased, 1 gene (FGF-9) decreased, and 1 gene was unchanged. Six transcripts (HB-EGF, BMP-2, COX-2, LIF, PAR-2, and FGF-9) were evaluated using an ex vivo rat model of bladder distension. HB-EGF, BMP-2, COX-2, LIF, and PAR-2 increased with bladder stretch ex vivo, whereas FGF-9 decreased, consistent with expression changes observed in vitro. In silico analysis of microarray data using the FIRED algorithm identified c-jun, AP-1, ATF-2, and neurofibromin-1 (NF-1) as potential transcriptional mediators of stretch signals. Furthermore, the promoters of 9 of 13 stretch-responsive genes contained AP-1 binding sites. These observations identify stretch as a highly selective regulator of gene expression in bladder SMC. Moreover, they suggest that mechanical and growth factor signals converge on common transcriptional regulators that include members of the AP-1 family.

Cyclic mechanical stretch induces VEGF and FGF-2 expression in pulmonary vascular smooth muscle cells

2002 ◽  
Vol 282 (5) ◽  
pp. L897-L903 ◽  
Author(s):  
Timothy P. Quinn ◽  
Marielle Schlueter ◽  
Scott J. Soifer ◽  
Jorge A. Gutierrez
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Vascular Development ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Cyclic Stretch ◽  
Dependent Manner ◽  
Pulmonary Artery Smooth Muscle

Vascular endothelial growth factor (VEGF) and basic (b) fibroblast growth factor (FGF-2/bFGF) are involved in vascular development and angiogenesis. Pulmonary artery smooth muscle cells express VEGF and FGF-2 and are subjected to mechanical forces during pulsatile blood flow. The effect of stretch on growth factor expression in these cells is not well characterized. We investigated the effect of cyclic stretch on the expression of VEGF and FGF-2 in ovine pulmonary artery smooth muscle cells. Primary confluent cells from 6-wk-old lambs were cultured on flexible silicon membranes and subjected to cyclic biaxial stretch (1 Hz; 5–25% stretch; 4–48 h). Nonstretched cells served as controls. Expression of VEGF and FGF-2 was determined by Northern blot analysis. Cyclic stretch induced expression of both VEGF and FGF-2 mRNA in a time- and amplitude-dependent manner. Maximum expression was found at 24 h and 15% stretch (VEGF: 1.8-fold; FGF-2: 1.9-fold). These results demonstrate that mechanical stretch regulates VEGF and FGF-2 gene expression, which could play a role in pulmonary vascular development or in postnatal pulmonary artery function or disease.

TNF-α induces MMP-9 expression via activation of Src/EGFR, PDGFR/PI3K/Akt cascade and promotion of NF-κB/p300 binding in human tracheal smooth muscle cells

2007 ◽  
Vol 292 (3) ◽  
pp. L799-L812 ◽  
Author(s):  
Chiang-Wen Lee ◽  
Chih-Chung Lin ◽  
Wei-Ning Lin ◽  
Kao-Chih Liang ◽  
Shue-Feng Luo ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Growth Factor Receptors ◽  
Tracheal Smooth Muscle ◽  
Dependent Manner ◽  
Akt Phosphorylation ◽  
Tnf Α ◽  
Phosphorylated Akt

TNF-α has been shown to induce matrix metalloproteinase-9 (MMP-9) expression, which, in turn, degrades extracellular matrix in the inflammatory responses. However, the inductive mechanisms of the MMP-9 by TNF-α remain unclear. In human tracheal smooth muscle cells, TNF-α induced MMP-9 expression and Akt phosphorylation in a time-dependent manner, which was attenuated by the inhibitors of Src (PP1), epidermal growth factor receptor (AG1478), PDGFR (AG1296), and PI3K (LY294002), respectively, revealed by reporter gene assay, RT-PCR, zymographic, and Western blot analyses. Transfection with the dominant negative mutants of c-Src (KM, K295M [kinase inactive mutant]), p85, and Akt (KA, K179A) also reduced MMP-9 expression. These findings indicated that MMP-9 expression was regulated by PI3K/Akt via the transactivation of growth factor receptors. Furthermore, LY294002 or wortmannin inhibited Akt phosphorylation but had no effect on NF-κB translocation, which was blocked by helenalin. Mutated NF-κB DNA binding element in the MMP-9 promoter and helenalin also attenuated MMP-9 expression, suggesting that PI3K/Akt and NF-κB independently regulated MMP-9 expression. To support this notion, immunofluorescence staining and immunoprecipitation were applied to characterize the transcription factors involved in these responses. The results showed that LY294002 and curcumin blocked Akt translocation into nucleus. In contrast, p300, acetyl-histone (H3), and NF-κB p65 were found to be coimmunoprecipitated with the phosphorylated Akt, indicating that these components associated with the MMP-9 promoter are revealed by chromatin immunoprecipitation assay. Thus, our study provides a new insight into the molecular mechanisms that TNF-α-stimulated Akt phosphorylation mediated through transactivation of Src and growth factor receptors may stimulate the recruitment of p300, assemble transcription factor (p65), and then lead to MMP-9 expression.

Stretch activates heparin-binding EGF-like growth factor expression in bladder smooth muscle cells

1998 ◽  
Vol 275 (5) ◽  
pp. C1247-C1254 ◽  
Author(s):  
John M. Park ◽  
Joseph G. Borer ◽  
Michael R. Freeman ◽  
Craig A. Peters
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Fold Increase ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Mrna Levels ◽  
Ang Ii ◽  
Heparin Binding ◽  
Bladder Smooth Muscle

Cultured rat bladder smooth muscle cells (SMC) were grown on collagen-coated silicone membranes and subjected to continuous cycles of stretch-relaxation. Semiquantitative RT-PCR analysis revealed a time-dependent increase in heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) mRNA levels after stretch, with maximal levels appearing after 4 h. Immunostaining for proHB-EGF revealed higher levels of HB-EGF protein in the stretched than in the nonstretched SMC. The ANG II receptor type 1 antagonist losartan markedly suppressed stretch-activated HB-EGF expression. ANG II levels were 3.3-fold higher in the stretch- than in the non-stretch-conditioned media. Stretch stimulation of bladder SMC that had been transiently transfected with an HB-EGF promoter-luciferase expression construct resulted in an 11-fold increase in reporter activity. Mechanical stretch induced a 4.7-fold increase in tritiated thymidine incorporation rate, and this was reduced by 25% in the presence of losartan. We conclude that mechanical stretch activates HB-EGF gene expression in bladder SMC and that this is mediated in part by autocrine ANG II secretion.

Sorghum Fermented by Aspergillus oryzae NK Enhances Inhibition of Vascular Inflammation in TNF-α-stimulated Human Aortic Smooth Muscle Cells

2018 ◽  
Vol 88 (5-6) ◽  
pp. 309-318
Author(s):  
Hae Seong Song ◽  
Jung-Eun Kwon ◽  
Hyun Jin Baek ◽  
Chang Won Kim ◽  
Hyelin Jeon ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Inflammatory Response ◽  
Smooth Muscle Cells ◽  
Adhesion Molecule ◽  
Vascular Inflammation ◽  
Muscle Cells ◽  
Aortic Smooth Muscle Cells ◽  
Aortic Smooth Muscle ◽  
Tnf Α ◽  
Cox 2

Abstract. Sorghum bicolor L. Moench is widely grown all over the world for food and feed. The effects of sorghum extracts on general inflammation have been previously studied, but its anti-vascular inflammatory effects are unknown. Therefore, this study investigated the anti-vascular inflammation effects of sorghum extract (SBE) and fermented extract of sorghum (fSBE) on human aortic smooth muscle cells (HASMCs). After the cytotoxicity test of the sorghum extract, a series of experiments were conducted. The inhibition effects of SBE and fSBE on the inflammatory response and adhesion molecule expression were measured using treatment with tumor necrosis factor-α (TNF-α), a crucial promoter for the development of atherosclerotic lesions, on HASMCs. After TNF-α (10 ng/mL) treatment for 2 h, then SBE and fSBE (100 and 200 μg/mL) were applied for 12h. Western blotting analysis showed that the expression of vascular cell adhesion molecule-1 (VCAM-1) (2.4-fold) and cyclooxygenase-2 (COX-2) (6.7-fold) decreased, and heme oxygenase-1 (HO-1) (3.5-fold) increased compared to the TNF-α control when treated with 200 μg/mL fSBE (P<0.05). In addition, the fSBE significantly increased the expression of HO-1 and significantly decreased the expression of VCAM-1 and COX-2 compared to the TNF-α control in mRNA level (P<0.05). These reasons of results might be due to the increased concentrations of procyanidin B1 (about 6-fold) and C1 (about 30-fold) produced through fermentation with Aspergillus oryzae NK for 48 h, at 37 °C. Overall, the results demonstrated that fSBE enhanced the inhibition of the inflammatory response and adherent molecule expression in HASMCs.

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