173: Lipid Rafts are Negative Regulators of TGFβ Signaling in Ureteral Smooth Muscle Cells

2004 ◽  
Vol 171 (4S) ◽  
pp. 46-46
Author(s):  
Carlos R. Estrada ◽  
Theodora Danciu ◽  
Maximilian Stehr ◽  
Joseph Khoury ◽  
Keith R. Solomon ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Lipid Rafts ◽  
Muscle Cells ◽  
Negative Regulators ◽  
Tgfβ Signaling

Urokinase-receptor-mediated phenotypic changes in vascular smooth muscle cells require the involvement of membrane rafts

2009 ◽  
Vol 423 (3) ◽  
pp. 343-351 ◽  
Author(s):  
Julia Kiyan ◽  
Graham Smith ◽  
Hermann Haller ◽  
Inna Dumler
Keyword(s):  
Smooth Muscle ◽  
Cell Migration ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Lipid Rafts ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Caveolin 1 ◽  
Phenotypic Changes ◽  
Dependent Cell

The cholesterol-enriched membrane microdomains lipid rafts play a key role in cell activation by recruiting and excluding specific signalling components of cell-surface receptors upon receptor engagement. Our previous studies have demonstrated that the GPI (glycosylphosphatidylinositol)-linked uPAR [uPA (urokinase-type plasminogen activator) receptor], which can be found in lipid rafts and in non-raft fractions, can mediate the differentiation of VSMCs (vascular smooth muscle cells) towards a pathophysiological de-differentiated phenotype. However, the mechanism by which uPAR and its ligand uPA regulate VSMC phenotypic changes is not known. In the present study, we provide evidence that the molecular machinery of uPAR-mediated VSMC differentiation employs lipid rafts. We show that the disruption of rafts in VSMCs by membrane cholesterol depletion using MCD (methyl-β-cyclodextrin) or filipin leads to the up-regulation of uPAR and cell de-differentiation. uPAR silencing by means of interfering RNA resulted in an increased expression of contractile proteins. Consequently, disruption of lipid rafts impaired the expression of these proteins and transcriptional activity of related genes. We provide evidence that this effect was mediated by uPAR. Similar effects were observed in VSMCs isolated from Cav1−/− (caveolin-1-deficient) mice. Despite the level of uPAR being significantly higher after the disruption of the rafts, uPA/uPAR-dependent cell migration was impaired. However, caveolin-1 deficiency impaired only uPAR-dependent cell proliferation, whereas cell migration was strongly up-regulated in these cells. Our results provide evidence that rafts are required in the regulation of uPAR-mediated VSMC phenotypic modulations. These findings suggest further that, in the context of uPA/uPAR-dependent processes, caveolae-associated and non-associated rafts represent different signalling membrane domains.

scholarly journals Transforming growth factor-β plays divergent roles in modulating vascular remodeling, inflammation, and pulmonary fibrosis in a murine model of scleroderma

2017 ◽  
Vol 312 (1) ◽  
pp. L22-L31 ◽  
Author(s):  
Kazuyuki Tsujino ◽  
Nilgun Isik Reed ◽  
Amha Atakilit ◽  
Xin Ren ◽  
Dean Sheppard
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Vascular Remodeling ◽  
Transforming Growth Factor ◽  
Muscle Cells ◽  
Transforming Growth Factor Β ◽  
Tgfβ Signaling ◽  
Pulmonary Vascular Remodeling ◽  
Global Inhibition

The efficacy and feasibility of targeting transforming growth factor-β (TGFβ) in pulmonary fibrosis and lung vascular remodeling in systemic sclerosis (SSc) have not been well elucidated. In this study we analyzed how blocking TGFβ signaling affects pulmonary abnormalities in Fos-related antigen 2 (Fra-2) transgenic (Tg) mice, a murine model that manifests three important lung pathological features of SSc: fibrosis, inflammation, and vascular remodeling. To interrupt TGFβ signaling in the Fra-2 Tg mice, we used a pan-TGFβ-blocking antibody, 1D11, and Tg mice in which TGFβ receptor type 2 ( Tgfbr2) is deleted from smooth muscle cells and myofibroblasts (α-SMA-CreER; Tgfbr2 flox/flox). Global inhibition of TGFβ by 1D11 did not ameliorate lung fibrosis histologically or biochemically, whereas it resulted in a significant increase in the number of immune cells infiltrating the lungs. In contrast, 1D11 treatment ameliorated the severity of pulmonary vascular remodeling in Fra-2 Tg mice. Similarly, genetic deletion of Tgfbr2 from smooth muscle cells resulted in improvement of pulmonary vascular remodeling in the Fra-2 Tg mice, as well as a decrease in the number of Ki67-positive vascular smooth muscle cells, suggesting that TGFβ signaling contributes to development of pulmonary vascular remodeling by promoting the proliferation of vascular smooth muscle cells. Deletion of Tgfbr2 from α-smooth muscle actin-expressing cells had no effect on fibrosis or inflammation in this model. These results suggest that efforts to target TGFβ in SSc will likely require more precision than simply global inhibition of TGFβ function.

A quantitative proteomic analysis of growth factor-induced compositional changes in lipid rafts of human smooth muscle cells

PROTEOMICS ◽  
2005 ◽  
Vol 5 (18) ◽  
pp. 4733-4742 ◽  
Author(s):  
Dawn L. MacLellan ◽  
Hanno Steen ◽  
Rosalyn M. Adam ◽  
Monica Garlick ◽  
David Zurakowski ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Lipid Rafts ◽  
Proteomic Analysis ◽  
Muscle Cells ◽  
Quantitative Proteomic Analysis ◽  
Compositional Changes

Abstract P511: Targeting Il-1β Protects From Aortic Aneurysms Induced by Disrupted Tgfβ Signaling in Smooth Muscle Cells

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Daniela Carnevale ◽  
Raimondo Carnevale ◽  
Francesco Da Ros ◽  
Roberta Iacobucci ◽  
Manuel Casaburo ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Time Course ◽  
Molecular Mechanisms ◽  
Muscle Cells ◽  
Ascending Aorta ◽  
Aortic Aneurysms ◽  
Tgfβ Signaling ◽  
Aneurysm Formation ◽  
Aortic Pathology

Aortic aneurysms represent a life-threatening condition because of the current lack of effective treatments. Aneurysm formation is typically associated with extracellular matrix remodeling and persistent inflammation. Although the molecular mechanisms underlying aortic pathology remain largely unclear, TGFβ signaling is unquestionably implied and its downstream target Smad4 showed protective functions for maintenance of aortic walls’ integrity. Using mice with smooth muscle cells (SMCs) specific deletion of Smad4 in the adult ( Smad4 -SMC iko ), developing spontaneous aneurysms (Ascending Aorta Diameter: Smad4 -SMC iko 2.15±0.03; Smad4 -SMC wt 1.7±0.03;***p< 0.001), we investigated the molecular mechanisms activated by dysregulation of TGFβ signaling. Structural disarrangement of ascending aorta in Smad4 -SMC iko mice was clearly appreciated early after Smad4 deletion as discrete breaks of elastic lamellae (breaks/section: Smad4 -SMC iko 2.05±0.5; Smad4 -SMC wt 0.83±0.4;***p< 0.001). Interestingly, the islands of damage in the aorta of Smad4 -SMC iko were enriched of immune infiltrate, mainly monocytes/macrophages, as indicated by FACS and immunofluorescence. We then analyzed several pathways downstream to Smad4 inhibition, finding a selective activation of NF-kB/IL-1β in SMCs. To test the relevance of this pathway in the formation of aneurysms, we deleted Smad4 in SMCs of mice with Il1r1 null background ( Smad4 -SMC iko ; Il1r1 -/- ). Ultrasonographic analyses revealed that ablation of IL1 receptor1 protected Smad4 -SMC iko mice from the progression of pathology and improved their overall survival. In the end, to test the translational potential of our findings, we neutralized IL-1β signaling with the clinically relevant murine version of the FDA-approved clinical drug canakinumab. During a time course of 16 weeks, while a weekly administration of control immunoglobulins did not change aneurysm progression in Smad4 -SMC iko mice, treatment with anti-IL-1β antibody significantly hampered aneurysm formation in the aorta ( Smad4 -SMC iko +anti- IL-1β 1.85±0.02; Smad4 -SMC iko +anti-IgG 2.09±0.03; ***p< 0.001) These findings identify a mechanistic target for controlling aneurysms progression induced by disrupted TGFβ signaling.

CAVEOLAE ARE NEGATIVE REGULATORS OF TRANSFORMING GROWTH FACTOR-β1 SIGNALING IN URETERAL SMOOTH MUSCLE CELLS

2004 ◽  
Vol 172 (6 Part 1) ◽  
pp. 2451-2455 ◽  
Author(s):  
MAXIMILIAN STEHR ◽  
CARLOS R. ESTRADA ◽  
JOSEPH KHOURY ◽  
THEODORA E. DANCIU ◽  
MARYROSE P. SULLIVAN ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Smooth Muscle Cells ◽  
Transforming Growth Factor ◽  
Muscle Cells ◽  
Transforming Growth Factor Β1 ◽  
Negative Regulators

Immunogold localization of HMB-45 antigen in pulmonary lymphangiomyomatosis

1995 ◽  
Vol 53 ◽  
pp. 998-999
Author(s):  
J.M. Minda ◽  
E. Dessy ◽  
G. G. Pietra
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Muscle Cells ◽  
Ultrastructural Localization ◽  
Reproductive Age ◽  
Thin Sections ◽  
Smooth Muscle Proliferation ◽  
Hmb 45

Pulmonary lymphangiomyomatosis (PLAM) is a rare disease occurring exclusively in women of reproductive age. It involves the lungs, lymph nodes and lymphatic ducts. In the lungs, it is characterized by the proliferation of smooth muscle cells around lymphatics in the bronchovascular bundles, lobular septa and pleura The nature of smooth muscle proliferation in PLAM is still unclear. Recently, reactivity of the smooth muscle cells for HMB-45, a melanoma-related antigen has been reported by immunohistochemistry. The purpose of this study was the ultrastructural localization of HMB-45 immunoreactivity in these cells using gold-labeled antibodies.Lung tissue from three cases of PLAM, referred to our Institution for lung transplantation, was embedded in either Poly/Bed 812 post-fixed in 1% osmium tetroxide, or in LR White, without osmication. For the immunogold technique, thin sections were placed on Nickel grids and incubated with affinity purified, monoclonal anti-melanoma antibody HMB-45 (1:1) (Enzo Diag. Co) overnight at 4°C. After extensive washing with PBS, grids were treated with Goat-anti-mouse-IgG-Gold (5nm) (1:10) (Amersham Life Sci) for 1 hour, at room temperature.

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