scholarly journals Cavin-1 regulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Tomita ◽  
N Nakanishi ◽  
T Ogata ◽  
Y Tsuji ◽  
A Sakamoto ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Pulmonary Artery ◽  
Signaling Pathway ◽  
Knockout Mice ◽  
Bmp Signaling ◽  
Smad Signaling ◽  
Caveolin 1 ◽  
Smad Signaling Pathway

Abstract Background Pulmonary hypertension (PH) is a progressive disease associated with poor outcome. Caveolin-1 (Cav1) is a component of caveolae and classified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is a most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known. Purpose The aim of our study is to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway and explore the mechanism of downstream signal transduction of BMP signaling by the interaction between Caveolin and BMPRII. Methods Cav1 knockout mice were used to assess PH and caveolae in pulmonary artery endothelial cells were observed by electron microscope. Cav1 and Cavin-1, which is a component of caveolae and form a complex with Cav1, were knocked-down in human pulmonary artery endothelial cell (hPAEC) using siRNA and phosphorylation of Smad signal was evaluated. Apoptosis of these cells was explored by flow cytometry. We investigated the interaction between Cav1 and BMPRII, and evaluated whether Cavin-1 affects this interaction and signal transduction of BMP signaling. Results As previously described, deletion of Cav1 revealed disappearance of caveolae in pulmonary artery endothelial cells (PAECs), and Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy. We then examined roles of Cav1 in human PAECs (hPAECs). Cav1 knockdown in hPAECs reduced phosphorylation of Smad 1/5/9. In addition, Cav1 knockdown significantly increased hypoxia-induced apoptosis in hPAEC. Knockdown of Cavin-1 reversed phosphorylation of Smad 1/5/9 decreased by Cav1 knockdown in BMP9 stimulation. Cavin-1 reversed the expression of BMPRII decreased by overexpression of Cav1. Cav1 was associated with Cavin-1 at the plasma membrane in PAECs. Cav1 also associated with BMPRII at the membrane of hPAECs that was inhibited by Cavin-1, and Cavin-1 reduced the localization of BMPRII to the membrane of hPAECs. These results suggest that BMPRII interacts with Cav1 via Cavin-1-associated localization at the plasma membrane in hPAECs, resulting in regulating BMP/Smad signaling pathway and involving in the development of PAH. Conclusions Cavin-1 affects the interaction of Cav1 with BMPRII at the membrane of PAECs, and regulates BMP/Smad signaling. These results reveal a previously undescribed function of Cavin-Caveolin system in the development of PAH through regulation of BMP/Smad signaling. Funding Acknowledgement Type of funding source: None

scholarly journals Cavin-1 modulates BMP/Smad signaling through the interaction of Caveolin-1 with BMPRII in pulmonary artery endothelial cells

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
S Tomita ◽  
N Nakanishi ◽  
T Ogata ◽  
T Suga ◽  
Y Tsuji ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Pulmonary Artery ◽  
Western Blotting ◽  
Knockout Mice ◽  
Gene Mutations ◽  
Smad Signaling ◽  
Caveolin 1 ◽  
Pulldown Assay ◽  
Induced Apoptosis

Abstract Background Pulmonary hypertension (PH) is a progressive disease associated with poor outcomes. Caveolin-1 (Cav1) and Cavin-1 are components of caveolae, and Cav1 is identified as a related gene of pulmonary arterial hypertension (PAH). Gene mutations of bone morphogenetic protein type II receptor (BMPRII) is the most common cause of PAH. BMPRII is localized in caveolae and associates with Cav1. However, the role of the Caveolin-Cavin system on the BMP/Smad signaling and the PAH progression has not been well-known. Purpose Our study aims to investigate the relationship between Caveolin-Cavin system and BMP/Smad signaling pathway in pulmonary artery endothelial cells (PAECs). [Methods] Cav1 knockout mice were used to assess PH, and caveolae in PAECs were observed by electron microscope. After knocking down Cav1 and/or Cavin-1 in human PAECs (hPAECs) using siRNA, we evaluated the phosphorylation of Smad by Western blotting. Apoptosis was explored by flow cytometry. To assess the interaction between Cav1 and BMPRII, and the effect of Cavin-1 for this interaction and BMP/Smad signaling, we performed immunoprecipitation, Co-immunostaining, Proximal Ligation Assay (PLA), GST pulldown assay, and Western blotting. Results As in previous reports, Cav1 knockout mice exhibited PH with pulmonary vascular remodeling and right ventricular hypertrophy and PAECs isolated from Cav1 knockout mice showed caveolae disappearance. Cav1 knockdown in hPAECs reduced BMPRII at the plasma membrane and Smad 1/5/9 phosphorylation. Cav1 knockdown also significantly increased hypoxia-induced apoptosis in hPAECs. Co-immunostaining revealed that Cav1 was associated with BMPRII at the membrane of hPAECs. Cavin-1 inhibited the interaction of BMPRII with Cav1 and reduced BMPRII localization on the membrane of hPAECs. GST pulldown assay revealed that Cavin-1 and BMPRII were associated with Cav1 through the scaffolding domain in Cav1. These findings suggest that Cavin-1 and BMPRII are competitively associated with Cav1. Cavin-1 knockdown improved the interaction between Cav1 and BMPRII and inhibited both BMPRII reduction at the plasma membrane and Smad 1/5/9 dephosphorylation. Conclusions Cavin-1 affects the interaction of Cav1 with BMPRII at the plasma membrane and modulates BMP/Smad signaling in PAECs. The binding of Cavin-1 to Cav1 enhances the interaction between BMPR2 and Cav1, resulting in stabilization of BMPRII localization at the plasma membrane in PAECs and prevention of BMP/Smad signaling attenuation, which is important for PAH development. FUNDunding Acknowledgement Type of funding sources: None.

scholarly journals Oxidized glutathione decreases luminal Ca2+ content of the endothelial cell ins(1,4,5)P3-sensitive Ca2+ store

1995 ◽  
Vol 312 (2) ◽  
pp. 485-489 ◽  
Author(s):  
P N Henschke ◽  
S J Elliott
Keyword(s):  
Signal Transduction ◽  
Endothelial Cells ◽  
Plasma Membrane ◽  
Endothelial Cell ◽  
Pulmonary Artery ◽  
Vascular Tissue ◽  
Oxidant Stress ◽  
Inhibitory Effect ◽  
Oxidized Glutathione ◽  
Intact Cells

The model oxidant, t-butyl hydroperoxide (t-buOOH), inhibits Ins(1,4,5)P3-dependent Ca2+ signalling in calf pulmonary artery endothelial cells. Metabolism of t-buOOH within the cytosol is coupled to the oxidation of glutathione. In this study, we investigated whether oxidized glutathione (GSSG) is the intracellular moiety responsible for mediating the effects of t-buOOH on Ca2+ signalling. The increase in cytosolic [Ca2+] stimulated by application of 2,5-di-t-butylhydroquinone (BHQ) was used to estimate the luminal Ca2+ content of the Ins(1,4,5)P3-sensitive store in intact cells. Luminal Ca2+ content was unaffected by t-buOOH (0.4 mM, 0-3 h) unless intracellular GSSG content was concomitantly elevated. The effect was specific for increased GSSG and was not replicated by depletion of GSH. These results suggest that cytosolic GSSG, produced endogenously within the endothelial cell, decreases the luminal Ca2+ content of Ins(1,4,5)P3-sensitive Ca2+ stores. Depletion of internal Ca2+ stores by GSSG may represent a key mechanism by which some forms of oxidant stress inhibit signal transduction in vascular tissue. At the plasma membrane, t-buOOH is known to inhibit the capacitative Ca2+ influx pathway. Increased intracellular GSSG potentiated the inhibitory effect of t-buOOH on Ca2+ influx, thereby providing the first evidence that activity of the capacitative Ca2+ influx channel is sensitive to thiol reagents formed endogenously within the cell.

Genome-Wide Computational Screen for Blood Stem Cell Enhancers Integrates RUNX1 and the BMP Signaling Pathway into the SCL Transcriptional Network.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4196-4196
Author(s):  
John E. Pimanda ◽  
Ian J. Donaldson ◽  
Marella F. Bruijn ◽  
Sarah J. Kinston ◽  
Kathy Knezevic ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Stem Cell ◽  
Transcription Factors ◽  
Signaling Pathway ◽  
Bmp Signaling ◽  
Hematopoietic Stem ◽  
Genome Wide ◽  
A Genome ◽  
Smad Signaling Pathway ◽  
Runx1 Expression

Abstract Hematopoietic stem cell (HSC) development is regulated by several signaling pathways and a number of key transcription factors, which include Scl/Tal1, Runx1 and members of the Smad family. However, it remains unclear how these various determinants interact. Using a genome-wide computational screen based on the well-characterized Scl +19 HSC enhancer, we have identified a related Smad6 enhancer that also targets expression to blood and endothelial cells in transgenic mice. We show that at E10.5, Smad6 and Bmp4 transcripts are concentrated along the ventral pole of the dorsal aorta and resemble Runx1 expression in the aorta-gonad-mesonephros (AGM) region where HSCs originate. Moreover, Smad6 binds and inhibits Runx1 activity whereas Smad1, a mediator of Bmp4 signaling, transactivates the Runx1 promoter. Taken together, our results integrate three key determinants of HSC development; the Scl network, Runx1 activity and the Bmp4/Smad signaling pathway.

Sign in / Sign up

Export Citation Format

Share Document