Cyclic stretch regulates autocrine IGF-I in vascular smooth muscle cells: implications in vascular hyperplasia

1999 ◽  
Vol 276 (4) ◽  
pp. E697-E705 ◽  
Author(s):  
Paul R. Standley ◽  
Tamar J. Obards ◽  
Cherie L. Martina
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Systolic Hypertension ◽  
Cyclic Stretch ◽  
Cation Channels ◽  
Igf I

Vascular smooth muscle cells (VSMC) subjected to acute or chronic stretch display enhanced growth rates in vitro and in vivo. Clinical examples of vascular hyperplasia (e.g., systolic hypertension and postinjury restenosis) suggest that local insulin-like growth factor I (IGF-I) expression is enhanced. Therefore, we investigated the role of in vitro cyclic stretch on rat VSMC IGF-I secretion and cellular growth. In serum-free medium, cyclic stretch (1 Hz at 120% resting length for 48 h) stimulated thymidine incorporation ∼40% above that seen in nonstretched cells. Graded stretch magnitude (100–125% resting length) yielded graded increases in VSMC growth. Exogenous IGF-I increased growth of serum-starved, nonstretched VSMC in a dose-dependent manner, with maximal growth seen with 10−7 M. IGF-I secretion from stretched cells was 20- to 30-fold greater than from those cells cultured in a static environment. Stretch-induced increases in growth were completely blocked on addition of anti-IGF-I and partially blocked with platelet-derived growth factor (PDGF) antibodies and with a tyrosine kinase inhibitor (tyrphostin-1). Finally, blockade of stretch-activated cation channels with GdCl3 profoundly inhibited stretch-induced growth. We conclude that stretch increases VSMC IGF-I secretion and that such autocrine IGF-I is required for stretch-induced growth. PDGF and stretch-sensitive cation channels are likely additional components of a complex pathway that regulates stretch-induced VSMC seen in systolic hypertension and postinjury restenosis.

scholarly journals SIRT1 and FOXO Mediate Contractile Differentiation of Vascular Smooth Muscle Cells under Cyclic Stretch

2015 ◽  
Vol 37 (5) ◽  
pp. 1817-1829 ◽  
Author(s):  
Kai Huang ◽  
Zhi-Qiang Yan ◽  
Dan Zhao ◽  
Si-Guo Chen ◽  
Li-Zhi Gao ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Mechanical Stretch ◽  
Cyclic Stretch ◽  
Underlying Mechanisms

Background/Aims: Physiological mechanical stretch in vivo helps to maintain the quiescent contractile differentiation of vascular smooth muscle cells (VSMCs), but the underlying mechanisms are still unclear. Here, we investigated the effects of SIRT1 in VSMC differentiation in response to mechanical cyclic stretch. Methods and Results: Rat VSMCs were subjected to 10%-1.25Hz-cyclic stretch in vitro using a FX-4000T system. The data indicated that the expression of contractile markers, including α-actin, calponin and SM22α, was significantly enhanced in VSMCs that were subjected to cyclic stretch compared to the static controls. The expression of SIRT1 and FOXO3a was increased by the stretch, but the expression of FOXO4 was decreased. Decreasing SIRT1 by siRNA transfection attenuated the stretch-induced expression of contractile VSMC markers and FOXO3a. Furthermore, increasing SIRT1 by either treatment with activator resveratrol or transfection with a plasmid to induce overexpression increased the expression of FOXO3a and contractile markers, and decreased the expression of FOXO4 in VSMCs. Similar trends were observed in VSMCs of SIRT1 (+/-) knockout mice. The overexpression of FOXO3a promoted the expression of contractile markers in VSMCs, while the overexpression of FOXO4 demonstrated the opposite effect. Conclusion: Our results indicated that physiological cyclic stretch promotes the contractile differentiation of VSMCs via the SIRT1/FOXO pathways and thus contributes to maintaining vascular homeostasis.

Vascular Endothelial Growth Factor-Induced Migration of Vascular Smooth Muscle Cells in Vitro

1999 ◽  
Vol 58 (2) ◽  
pp. 128-136 ◽  
Author(s):  
Cynthia L. Grosskreutz ◽  
Bela Anand-Apte ◽  
Cécile Dupláa ◽  
Timothy P. Quinn ◽  
Bruce I. Terman ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor

Interaction of angiotensin II and the insulin-like growth factor system in vascular smooth muscle cells

1999 ◽  
Vol 277 (2) ◽  
pp. H499-H507 ◽  
Author(s):  
Thomas Gustafsson ◽  
Peter Andersson ◽  
Yun Chen ◽  
Jan Olof Magnusson ◽  
Hans J. Arnqvist
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Dna Synthesis ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Ang Ii ◽  
Igf I

We studied the effects and interactions of ANG II and the insulin-like growth factor (IGF) system in cultured rat aortic smooth muscle cells. ANG II (1 μM) and IGF-I (10 nM) stimulated both DNA and protein synthesis. The effects of the two peptides in combination were additive or more than additive. The AT1 receptor antagonist losartan (10 and 100 μM) blocked their synergistic effect on DNA synthesis. IGF binding protein (IGFBP)-1 inhibited the effect of IGF-I but not that of ANG II on DNA synthesis. IGF-I stimulated gene expression of IGFBP-2 and IGFBP-4. ANG II decreased IGF-I, IGFBP-2, and IGFBP-4 transcripts but increased the IGF-I receptor transcript. IGF-I and ANG II in combination had similar effects on gene expression as ANG II alone. The IGFBP-2 and IGFBP-4 peptides could be detected in the conditioned medium. Our results show that ANG II and IGF-I have synergistic effects on vascular smooth muscle cells and that they interact in several ways.

Hepatoma-derived growth factor enhances osteoblastic transformation of rat aortic vascular smooth muscle cells in vitro

Life Sciences ◽  
2020 ◽  
Vol 256 ◽  
pp. 117964
Author(s):  
Cheng-I Cheng ◽  
Huoy-Rou Chang ◽  
Ming-Hong Tai ◽  
Ming-Huei Chou ◽  
Guan-Ting Chen ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells

scholarly journals Proteomics reveals Rictor as a noncanonical TGF-β signaling target during aneurysm progression in Marfan mice

2018 ◽  
Vol 315 (5) ◽  
pp. H1112-H1126 ◽  
Author(s):  
Sarah J. Parker ◽  
Aleksandr Stotland ◽  
Elena MacFarlane ◽  
Nicole Wilson ◽  
Amanda Orosco ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Aortic Aneurysm ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Transforming Growth Factor ◽  
Mammalian Target Of Rapamycin

The objective of the present study was to 1) analyze the ascending aortic proteome within a mouse model of Marfan syndrome (MFS; Fbn1C1041G/+) at early and late stages of aneurysm and 2) subsequently test a novel hypothesis formulated on the basis of this unbiased proteomic screen that links changes in integrin composition to transforming growth factor (TGF)-β-dependent activation of the rapamycin-independent component of mammalian target of rapamycin (Rictor) signaling pathway. Ingenuity Pathway Analysis of over 1,000 proteins quantified from the in vivo MFS mouse aorta by data-independent acquisition mass spectrometry revealed a predicted upstream regulator, Rictor, that was selectively activated in aged MFS mice. We validated this pattern of Rictor activation in vivo by Western blot analysis for phosphorylation on Thr1135 in a separate cohort of mice and showed in vitro that TGF-β activates Rictor in an integrin-linked kinase-dependent manner in cultured aortic vascular smooth muscle cells. Expression of β3-integrin was upregulated in the aged MFS aorta relative to young MFS mice and wild-type mice. We showed that β3-integrin expression and activation modulated TGF-β-induced Rictor phosphorylation in vitro, and this signaling effect was associated with an altered vascular smooth muscle cell proliferative-migratory and metabolic in vitro phenotype that parallels the in vivo aneurysm phenotype in MFS. These results reveal that Rictor is a novel, context-dependent, noncanonical TGF-β signaling effector with potential pathogenic implications in aortic aneurysm. NEW & NOTEWORTHY We present the most comprehensive quantitative analysis of the ascending aortic aneurysm proteome in Marfan syndrome to date resulting in novel and potentially wide-reaching findings that expression and signaling by β3-integrin constitute a modulator of transforming growth factor-β-induced rapamycin-independent component of mammalian target of rapamycin (Rictor) signaling and physiology in aortic vascular smooth muscle cells.

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