Abstract 2681: Mutations in Smooth Muscle-Specific Contractile Proteins Cause Familial Thoracic Aortic Aneurysms and Dissections and Lead to Increased IGF-1 Expression

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Christina L Papke ◽  
Hariyadarshi Pannu ◽  
Dong-Chuan Guo ◽  
Nili Avidan ◽  
Van Tran-Fadulu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Contractile Proteins ◽  
Dermal Fibroblasts ◽  
Aortic Aneurysms ◽  
Trophic Factors ◽  
Aortic Tissue ◽  
Thoracic Aortic Aneurysms ◽  
Protein Levels ◽  
Tgf Β1

Aortic aneurysms and dissections are the most common disorders affecting the aorta, and are a major cause of morbidity and mortality in the United States. Familial thoracic aortic aneurysms and dissections (FTAAD) are inherited in an autosomal dominant manner with variable expression and decreased penetrance. The disorder is genetically heterogeneous with four loci and three genes identified. Mutations in either TGFBR2 , encoding the transforming growth factor β (TGF-β) type II receptor, or MYH11 , encoding the smooth muscle cell (SMC)-specific β-myosin heavy chain, were previously found to cause FTAAD. Recently, positional cloning identified smooth muscle α-actin ( ACTA2 ) mutations as a novel cause in 10% of FTAAD. Mutations in ACTC and MYH7 cause hypertrophic cardiomyopathy (HCM), characterized by myocyte disarray and upregulation of mitotic and trophic factors. Histologic examination of aortic tissue from patients with ACTA2 (n = 6) and MYH11 (n = 2) mutations revealed SMC disarray in the aortic media similar to that seen in HCM. Furthermore, we hypothesized that mutations in ACTA2 and MYH11 cause a similar increase of mitotic and trophic factors in SMCs. The expression of two factors known to be increased in HCM, TGF-β1 and insulin-like growth factor 1 (IGF-1), were analyzed in patients’ aortic SMCs and dermal myofibroblasts. No changes in TGF-β1 were found; however, both mRNA, as measured by Q-PCR (p<0.05), and protein levels, as assessed by immunostaining, of IGF-1 were markedly increased in MYH11 and two ACTA2 mutant SMCs and aortic tissue compared with control SMCs and tissue. Differentiation of dermal fibroblasts into myofibroblasts was accomplished using TGF-β1 treatment; myofibroblast differentiation was confirmed by assessing α-actin mRNA and protein levels in untreated vs. TGF-β1-treated fibroblasts. Upon differentiation, patients’ myofibroblasts (n = 3) demonstrated increased IGF-1 expression compared with controls (p<0.05), similar to the increased IGF-1 expression by SMCs. In conclusion, IGF-1 secretion is increased in response to defects in SMC contractile proteins in SMCs and myofibroblasts. Future studies will clarify the role of IGF-1 in FTAAD and identify the pathways leading to increased IGF-1 expression.

Elevated expression of connective tissue growth factor, osteopontin and increased collagen content in human ascending thoracic aortic aneurysms

Vascular ◽  
2013 ◽  
Vol 22 (1) ◽  
pp. 20-27 ◽  
Author(s):  
YH Meng ◽  
C Tian ◽  
L Liu ◽  
L Wang ◽  
Q Chang
Keyword(s):  
Growth Factor ◽  
Connective Tissue ◽  
Connective Tissue Growth Factor ◽  
Tissue Growth ◽  
Aortic Aneurysms ◽  
Collagen Content ◽  
Control Group ◽  
Mrna Levels ◽  
Thoracic Aortic Aneurysms ◽  
Protein Levels

Little is known about the molecular mechanisms of ascending thoracic aortic aneurysms (ATAAs). Abnormal extracellular matrix changes and variations of vascular smooth muscle cells (VSMCs) have been implicated in abdominal aortic aneurysm formation. Our objective was to investigate the alterations of collagen, stimulators of collagen synthesis and synthetic VSMCs in patients with ATAA. Surgical samples from ATAA were taken from 20 patients, and 18 control aortas were obtained during coronary artery bypass surgery. All aortic wall specimens were fixed for histology and immunohistochemistry for collagen, connective tissue growth factor (CTGF) and osteopontin. Realtime polymerase chain reaction was used to determine their mRNA expression. Histology and semi-quantitative analysis demonstrated that protein levels of collagen, CTGF and osteopontin significantly increased by 1.9-, 1.4- and 2.2-fold, respectively ( P < 0.01 for all) in the ATAA group than in the control group. Similar results were shown in mRNA levels of type Iα1and IIIα1 collagen, CTGF and osteopontin. The protein levels of CTGF and osteopontin were positively correlated with aortic diameter ( r = 0.67, r = 0.73; P < 0.01 for both). In conclusion, overexpression of aortic CTGF and synthetic VSMCs marker (osteopontin), which is likely to be responsible for elevated aortic collagen content, may provide a potential mechanism for aneurysmal enlargement.

Abstract 4275: TGFBR2 Mutations Reduce Expression of Contractile Proteins in Aortic Smooth Muscle Cells and Predispose Individuals to Thoracic Aortic Aneurysms and Dissections

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Sakiko Inamoto ◽  
Callie Kwartler ◽  
Andrea Lafont ◽  
Yao Yun Liang ◽  
Van Tran Fadulu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Matched Control ◽  
Muscle Cells ◽  
Contractile Proteins ◽  
Aortic Aneurysms ◽  
Gain Of Function ◽  
Age And Gender ◽  
Thoracic Aortic Aneurysms ◽  
And Gender

Mutations in the TGF-β receptor type II gene ( TGFBR2 ) cause thoracic aortic aneurysms and dissections (TAAD). Studies have suggested a gain of function effect for these mutations, leading to increased TGF-β signaling in the aortic media and resulting in vascular disease. We sought to characterize the phenotype of smooth muscle cells (SMCs) harboring heterozygous missense TGFBR2 mutations and our data suggest that instead of a gain of function, TGFBR2 mutations cause TAAD as a result of a loss of function resulting in defective SMC differentiation. Using primary aortic SMCs from patients harboring TGFBR2 mutations (n=4), we show a global decrease in expression of SMC contractile proteins ( ACTA2 , MYH11 , CNN1 , SMTN , TPM1 , TPM2 , p <0.001) by quantitative PCR analysis when these cells are compared with age and gender matched control SMCs (n=4), along with no change in the expression of cytoskeletal proteins. Consistent with the decreased expression of contractile proteins in the mutant cells, there was increased expression of S100A4, a marker of de-differentiated SMCs (p<0.001). Analysis of fixed and frozen aortas from patients with TGFBR2 mutations (n=3) confirmed decreased in vivo expression of SMC contractile proteins when compared to control aortas (n=3). In control SMCs, addition of TGF- β significantly increased the expression of the SMC contractile proteins but the TGFBR2 SMCs showed no significant increase in expression of these proteins with TGF-β stimulation. We found that fibroblasts explanted from patients with TGFBR2 mutations (n=8) consistently fail to transform into myofibroblasts as assessed by expression of SMC contractile proteins after TGF-β stimulation, when compared with age and gender matched control fibroblasts (n=8). Finally, introduction of TGFBR2 missense mutations into a mouse mesenchymal embryonic cell line that is used as a model of SMC differentiation (10T1/2 cells) disrupts the expression of contractile proteins in these cells when assessed post-differentiation. These data suggest that TGFBR2 mutations disrupt differentiation of SMCs and myofibroblasts. This is the first genetic defect identified to lead to defective SMC differentiation.

Abstract 058: Transforming Growth Factor β1 Antagonizes Npr1 Expression and Vascular Signaling: Role of Transcription Factor δEF1 Transforming Growth Factor β1 Antagonizes Npr1 Expression and Vascular Signaling: Role of Transcription Factor δEF1

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Anagha Sen ◽  
Prerna Kumar ◽  
Sarah H Lindsey ◽  
Prasad V Katakam ◽  
Meaghan Bloodworth ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Protein Expression ◽  
Transforming Growth Factor ◽  
Fold Increase ◽  
Transforming Growth Factor Β1 ◽  
Protein Levels ◽  
Tgf Β1

The objective of the present study was to examine the repressive effect of transforming growth factor beta 1 (TGF-β1) in the regulation of Npr1 (coding for guanylyl cyclase/natriuretic peptide receptor-A; GC-A/NPRA) gene expression and vascular signaling. The rat thoracic aortic vascular smooth muscle cells (RTASMC) and denuded aortic rings were cultured in Dulbecco’s modified Eagle’s medium containing 10% fetal bovine serum and treated with TGF-β1 in a time-and dose-dependent manner. Treatment with TGF-β1 decreased NPRA mRNA and protein levels by 62% (0.42 ± 0.05 vs. control, 0.9 ± 0.02, p < 0.01) and 55% (9603 ± 860 vs. control, 22211 ± 1449, p < 0.01), respectively. TGF-β1 treatment significantly increased delta EF1 (δEF1) protein expression by 2.4-fold (907.9 ± 36.5. vs. control, 378.5 ± 10.3; p < 0.001) and enhanced its recruitment to Npr1 promoter. TGF-β1-treated RTASMCs and denuded aortic rings showed significant increases in α-smooth muscle actin (α-SMA) and collagen type 1 alpha 2 (COL1A2) protein expression, which were markedly attenuated by ANP treatments. The TGF-β1-pretreated cells showed 2.6-fold increase in α-SMA (control, 1523 ± 143, TGF-β1, 3997 ± 182 and TGF-β1 + ANP, 2172 ± 135) and 3.4-fold increase in COL1A2 (control, 1250 ± 77, TGF-β1, 4234 ± 110 and TGF-β1 + ANP, 1546 ± 57), respectively. In ex vivo experiments of denuded-aortic rings, TGF-β1 decreased Npr1 mRNA and protein levels by 62% (0.39 ± 0.06 vs. control 1.10 ± 0.01) and 70% (2609 ± 69 vs. control 5775 ± 123), respectively, and significantly (p < 0.0) increased the expression of TGF-β1-responsive proteins, namely α-SMA (2.6-fold) and COL1A2 (3.1-fold). Treatment with increasing concentrations of ANP (IC50=6x10 -9 M), relaxed denuded aortic rings contracted with prostaglandin F2α (PGF2α); however, pretreatment with TGF-β1 significantly attenuated ANP-mediated vascular relaxation after PFG2α contraction (ANP-treated, 68.68 ± 9.4 vs. TGF-β1 + ANP-treated 88.85 ± 4.7). The endothelium-intact vessels were not affected by TGF-β1 incubation. Together, the present results suggest that an antagonistic cascade exists between TGF-β1 pathways and ANP/NPRA signaling, which might be critical in the vascular remodeling and regulation of hypertension and cardiovascular homeostasis.

Abstract 294: Differential Expression of Hedgehog/Notch and Transforming Growth Factor-ß in Human Abdominal Aortic Aneurysms

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Adam Doyle ◽  
Eileen M Redmond ◽  
John P Cullen ◽  
Paul A Cahill ◽  
David Morrow
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Notch Signaling ◽  
Mrna Expression ◽  
Transforming Growth Factor ◽  
Aortic Aneurysms ◽  
Causative Role ◽  
Differentiation Gene ◽  
Tgf Β1

Objective: The molecular mechanisms leading to the development of Adnominal Aortic Aneurysms (AAA) remain poorly understood. The aim of this study was to determine the expression of Sonic Hedgehog (SHh), Transforming Growth Factor Beta (TGF-β) and Notch signaling components in aneurysmal and non-aneurysmal aorta in vivo and demonstrate SHh control of Notch, TGF- β1 and SMC differentiation in vitro. Methods: Paired tissue samples were obtained from aneurysmal and non-aneurysmal (control) segments of the aortic wall of at least 8 patients with suitable anatomy undergoing open repair of infrarenal AAA. Protein and mRNA expression levels were determined by western blot analysis and quantitative Real-time PCR. Results: Aneurysm development resulted in a significant reduction in vascular smooth muscle (vSMC) differentiation gene protein and mRNA levels for α-actin and SMC22α, respectively. In parallel, significant reductions in Hh and Notch signaling component expression was observed in aneurysmal tissue when compared to control, concurrent with increased TGF-β1 expression. In vitro, Hh signaling inhibition with cyclopamine (40μmol/L) treatment for 24 h in human aortic smooth muscle cells (HASMC), resulted in decreased Hh/Notch signaling component and vSMC differentiation gene expression. Moreover, cyclopamine significantly increased TGF-β1 mRNA expression. Conclusion: These results suggest that SHh/Notch and TGFβ signaling are differentially regulated in aneurysmal tissue, compared with non-aneurysmal tissue. Changes in these signaling pathways and the resulting changes in vSMC content may play a causative role in the development of AAA.

Abstract 297: Cyclic GMP Reduces Vascular Smooth Muscle Migration through Inhibition of TGF-ß1/Smad Signaling

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Jackson R Vuncannon ◽  
Joshua D Stone ◽  
Danielle N Martin ◽  
Chintamani N Joshi ◽  
Shaquria P Adderley ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Cyclic Gmp ◽  
Transforming Growth Factor ◽  
Soluble Guanylate Cyclase ◽  
Sandwich Elisa ◽  
Cell Lysates ◽  
Tgf Β1

Abnormal vascular smooth muscle (VSM) growth remains an elemental foundation of vasculoproliferative disorders including atherosclerosis and restenosis. Many second messenger, cytokine, and growth factor signals mediate control of VSM growth, and among these is transforming growth factor (TGF)-β1, a pluripotent cytokine with wide-ranging yet often opposite effects in VSM. Cyclic nucleotide signaling also exerts powerful growth control of VSM, and our previous work has helped establish a biological link between cyclic GMP and TGF-β1 in injured carotid arteries. The current study characterized the influence of cyclic GMP on TGF-β1 and its receptor-activated Smad3 in rat primary VSM cells. The heme-dependent soluble guanylate cyclase (sGC) stimulator BAY 41-2272 (BAY41) significantly increased cyclic GMP and site-specific phosphorylation of vasodilator-activated serum phosphoprotein (VASP) in manner indicative of active protein kinase G (PKG) and PKA signaling. Recombinant TGF-β1 (10 ng/ml) significantly stimulated phospho-Smad3 (Ser 423/425 ) and decreased inhibitory Smad7 in VSM cell homogenates, and using flow cytometry significantly increased cells in G 2 /M and expression of cyclins D and E and Cdk2 and Cdk4 while decreasing expression of inhibitory p21 and p27 after 24 hours compared to vehicle controls. TGF-β1 also significantly increased cell numbers compared to controls after 48 hours, thus confirming growth promoting capacities of TGF-β1 in VSM. In cell lysates double-sandwich ELISA revealed that BAY41 significantly reduces total and active TGF-β1, and Western analyses showed it significantly decreases total and phospho-Smad3 Ser423/425 expression and reduces MMP-2 and MMP-9 expression and activity (via column zymography) in both cell lysates and conditioned media after 1 and 48 hours. BAY41 also significantly reduced serum- and PDGF-stimulated cell migration between 6 and 18 hours using an in vitro scrape injury and a transwell assay. In comparison, inclusive effects of BAY41 were replicated by its prototype YC-1 and by the heme-independent sGC activator BAY 60-2770. These data clearly support growth protective capacities of cGMP in VSM and propose it operates through attenuation of TGF-β1/Smad3 signaling.

PDGF-BB-induced DNA synthesis is delayed by angiotensin II in vascular smooth muscle cells

1998 ◽  
Vol 274 (5) ◽  
pp. H1742-H1748 ◽  
Author(s):  
Gunilla Dahlfors ◽  
Yun Chen ◽  
Maria Wasteson ◽  
Hans J. Arnqvist
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Receptor Antagonist ◽  
Muscle Cells ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Β Receptor ◽  
Tgf Β1

The interaction of ANG II with platelet-derived growth factor (PDGF)-BB-induced DNA synthesis was studied in cultured rat aortic smooth muscle cells. PDGF-BB-induced DNA synthesis was delayed (∼6–8 h) by ANG II as shown by a time-course experiment. Losartan, an AT1-receptor antagonist, blocked the transient inhibitory effect of ANG II, whereas the AT2-receptor antagonist PD-123319 had no effect. Autocrine- or paracrine-acting transforming growth factor-β1 (TGF-β1), believed to be a mediator of ANG II-induced inhibitory effects, was not responsible for the delay of PDGF-BB-induced DNA synthesis, because a potent TGF-β1 neutralizing antibody could not reverse this effect of ANG II, nor was the delay of the PDGF-BB effect caused by inhibition of PDGF-β-receptor phosphorylation as shown by Western blot analysis of immunoprecipitated PDGF-β receptor. In conclusion, our results show that ANG II can exert a transient inhibitory effect on PDGF-BB-induced proliferation via the AT1 receptor.

Hypoxia-induced expression of VEGF is reversible in myocardial vascular smooth muscle cells

1997 ◽  
Vol 273 (2) ◽  
pp. H628-H633 ◽  
Author(s):  
J. W. Gu ◽  
T. H. Adair
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Conditioned Media ◽  
Dependent Manner ◽  
Induced Expression ◽  
Protein Levels

We determined whether hypoxia-induced expression of vascular endothelial growth factor (VEGF) can be reversed by a normoxic environment. Dog myocardial vascular smooth muscle cells (MVSMCs) were exposed to hypoxia (1% O2) for 24 h and then returned to normoxia (20% O2). VEGF protein levels increased by more than fivefold after 24 h of hypoxia and returned to baseline within 24 h of the return of the cells to normoxia. Northern blot analysis showed that hypoxia caused a 5.5-fold increase in VEGF mRNA, and, again, the expression was reversed after reinstitution of normoxia. Additional measurements showed that basic fibroblast growth factor and platelet-derived growth factor protein levels were not induced by hypoxia and that hypoxia caused a fourfold decrease in transforming growth factor-beta 1 protein levels. Hypoxia conditioned media from MVSMCs caused human umbilical vein endothelial cells to increase [3H]thymidine incorporation by twofold, an effect that was blocked in a dose-dependent manner by anti-human VEGF antibody. The hypoxia conditioned media had no effect on MVSMC proliferation. These findings suggest that VEGF expression can be bidirectionally controlled by tissue oxygenation, and thus support the hypothesis that VEGF is a physiological regulator of angiogenesis.

Adipolin/CTRP12 protects against pathological vascular remodelling through suppression of smooth muscle cell growth and macrophage inflammatory response

2019 ◽  
Vol 116 (1) ◽  
pp. 237-249 ◽  
Author(s):  
Hayato Ogawa ◽  
Koji Ohashi ◽  
Masanori Ito ◽  
Rei Shibata ◽  
Noriyoshi Kanemura ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Inflammatory Response ◽  
Transforming Growth Factor ◽  
Inflammatory Responses ◽  
Transforming Growth Factor Β ◽  
Vascular Remodelling ◽  
Vsmc Proliferation ◽  
Protein Levels ◽  
Β Receptor

AbstractAimsSecreted factors produced by adipose tissue are involved in the pathogenesis of cardiovascular disease. We previously identified adipolin, also known as C1q/TNF-related protein 12, as an insulin-sensitizing adipokine. However, the role of adipolin in vascular disease remains unknown. Here, we investigated whether adipolin modulates pathological vascular remodelling.Methods and resultsAdipolin-knockout (APL-KO) and wild-type (WT) mice were subjected to wire-induced injury of the femoral artery. APL-KO mice showed increased neointimal thickening after vascular injury compared with WT mice, which was accompanied by an enhanced inflammatory response and vascular cell proliferation in injured arteries. Adipolin deficiency also led to a reduction in transforming growth factor-β (TGF-β) 1 protein levels in injured arteries. Treatment of cultured macrophages with adipolin protein led to a reduction in lipopolysaccharide-stimulated expression of inflammatory mediators, including tumour necrosis factor (TNF)-α, interleukin (IL) 6, and monocyte chemotactic protein (MCP)-1. These effects were reversed by inhibition of TGF-β receptor II (TGF-βRII)/Smad2 signalling. Adipolin also reduced platelet-derived growth factor (PDGF)-BB-stimulated proliferation of vascular smooth muscle cells (VSMCs) through a TGF-βRII/Smad2-dependent pathway. Furthermore, adipolin treatment significantly increased TGF-β1 concentration in media from cultured VSMCs and macrophages.ConclusionThese data indicate that adipolin protects against the development of pathological vascular remodelling by attenuating macrophage inflammatory responses and VSMC proliferation.

Sign in / Sign up

Export Citation Format

Share Document