Caveolin-1 Deficiency Signaling Novel Mechanisms of Pulmonary Hypertension

2012 ◽  
Vol 02 (01) ◽  
Author(s):  
Khiem Tran YouYang Zhao
2002 ◽  
Vol 99 (17) ◽  
pp. 11375-11380 ◽  
Author(s):  
Y.-Y. Zhao ◽  
Y. Liu ◽  
R.-V. Stan ◽  
L. Fan ◽  
Y. Gu ◽  
...  

2021 ◽  
Vol 118 (17) ◽  
pp. e2023130118
Author(s):  
Zdravka Daneva ◽  
Corina Marziano ◽  
Matteo Ottolini ◽  
Yen-Lin Chen ◽  
Thomas M. Baker ◽  
...  

Recent studies have focused on the contribution of capillary endothelial TRPV4 channels to pulmonary pathologies, including lung edema and lung injury. However, in pulmonary hypertension (PH), small pulmonary arteries are the focus of the pathology, and endothelial TRPV4 channels in this crucial anatomy remain unexplored in PH. Here, we provide evidence that TRPV4 channels in endothelial cell caveolae maintain a low pulmonary arterial pressure under normal conditions. Moreover, the activity of caveolar TRPV4 channels is impaired in pulmonary arteries from mouse models of PH and PH patients. In PH, up-regulation of iNOS and NOX1 enzymes at endothelial cell caveolae results in the formation of the oxidant molecule peroxynitrite. Peroxynitrite, in turn, targets the structural protein caveolin-1 to reduce the activity of TRPV4 channels. These results suggest that endothelial caveolin-1–TRPV4 channel signaling lowers pulmonary arterial pressure, and impairment of endothelial caveolin-1–TRPV4 channel signaling contributes to elevated pulmonary arterial pressure in PH. Thus, inhibiting NOX1 or iNOS activity, or lowering endothelial peroxynitrite levels, may represent strategies for restoring vasodilation and pulmonary arterial pressure in PH.


2007 ◽  
Vol 204 (10) ◽  
pp. 2373-2382 ◽  
Author(s):  
Takahisa Murata ◽  
Michelle I. Lin ◽  
Yan Huang ◽  
Jun Yu ◽  
Phillip Michael Bauer ◽  
...  

Caveolin-1 (Cav-1) is the principal structural component of caveolae organelles in smooth muscle cells, adipocytes, fibroblasts, epithelial cells, and endothelial cells (ECs). Cav-1–deficient (Cav-1 knockout [KO]) mice are viable and show increases of nitric oxide (NO) production in vasculature, cardiomyopathy, and pulmonary dysfunction. In this study, we generated EC-specific Cav-1–reconstituted (Cav-1 RC) mice and reexamined vascular, cardiac, and pulmonary phenotypes. Cav-1 KO pulmonary arteries had decreased smooth muscle contractility and increased endothelial NO synthase activation and hypotension; the latter two effects were rescued completely in Cav-1 RC mice. Cav-1 KO mice exhibited myocardial hypertrophy, pulmonary hypertension, and alveolar cell hyperproliferation caused by constitutive activation of p42/44 mitogen-activated protein kinase and Akt. Interestingly, in Cav-1 RC mice, cardiac hypertrophy and pulmonary hypertension were completely rescued, whereas alveolar hyperplasia was partially recovered because of the lack of rescue of Cav-1 in bronchiolar epithelial cells. These results provide clear physiological evidence supporting the important role of cell type–specific Cav-1 expression governing multiple phenotypes in the vasculature, heart, and lung.


2017 ◽  
Vol 1 (9) ◽  
pp. 526-534 ◽  
Author(s):  
Kewal Asosingh ◽  
Nicholas Wanner ◽  
Kelly Weiss ◽  
Kimberly Queisser ◽  
Liya Gebreab ◽  
...  

Key Points Caveolin-1 deficiency in hematopoietic stem cells induces right heart disease. Healthy BM protects the right heart from maladaptation.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Zdravka Daneva ◽  
Corina Marziano ◽  
Matteo Ottolini ◽  
YEN LIN CHEN ◽  
Kwangseok Hong ◽  
...  

Background: Pulmonary hypertension (PH) is a degenerative disorder that is characterized by elevated vascular resistance and pulmonary arterial pressure (PAP). Endothelial transient receptor potential vanilloid 4 (TRPV4 EC ) ion channels represent an important Ca 2+ influx signaling mechanism that promotes vasodilation of small pulmonary arteries (PAs). Scaffolding protein caveolin-1 (Cav-1) has been shown to precipitate with TRPV4 channels in pulmonary endothelial cells in culture. Hypothesis: We hypothesized that the endothelial Cav-1-TRPV4 channel signaling in small PAs lowers PAP, and is impaired in PH. Methods: Inducible endothelium-specific KO mice for TRPV4 channel or Cav-1 were used to study the role of Cav-1-TRPV4 signaling in the regulation of resting PAP. Endothelium-specific P2Y2 receptor KO mice were used to test if Cav-1 provides a signaling scaffold for purinergic activation of TRPV4 EC channels. Endothelial Cav-1-TRPV4 signaling was assessed in PAs from two PH mouse models and PH patients. The role of NADPH oxidase (NOX1)- and inducible nitric oxide synthase (iNOS)-mediated peroxynitrite (PN), an oxidant molecule, in impairing Cav-1-TRPV4 signaling in PH was evaluated using NOX1-/- and iNOS-/- mice and pharmacological inhibitors. Results: We show that endothelial Cav-1-TRPV4 signaling in small PAs lowers resting PAP, and protects against the pathogenesis of PH. Endothelial Cav-1 provides a signaling scaffold for the activation of TRPV4 channels by endogenous purinergic receptor signaling. Moreover, TRPV4 EC channel activity and Cav-1-TRPV4 signaling are impaired in small PAs from two mouse models of PH and PH patients. Elevated levels of NOX1 and iNOS enzymes in caveolae resulted in PN formation close to Cav-1 in PH. Elevated PN targeted Cav-1 to lower Cav-1-TRPV4 signaling, thereby contributing to impaired vasodilation and increased PAP. Pharmacological inhibition of NOX1, iNOS, or PN rescued TRPV4 EC channel activity and vasodilation in PH. Conclusion: This study provides novel evidence that endothelial Cav-1-TRPV4 signaling lowers PAP and is impaired in PH. Inhibiting NOX1 or iNOS activity, or lowering endothelial PN levels may represent a novel strategy for restoring TRPV4 EC channel activity, vasodilation, and PAP.


2007 ◽  
Vol 292 (3) ◽  
pp. H1373-H1389 ◽  
Author(s):  
Somshuvra Mukhopadhyay ◽  
Fang Xu ◽  
Pravin B. Sehgal

We previously reported the disruption of caveolae/rafts, dysfunction of Golgi tethers, N-ethylmaleimide-sensitive factor-attachment protein (SNAP) receptor proteins (SNAREs), and SNAPs, and inhibition of anterograde trafficking in endothelial cells in culture and rat lung exposed to monocrotaline pyrrole (MCTP) as a prelude to the development of pulmonary hypertension. We have now investigated 1) whether this trafficking block affects subcellular localization and function of endothelial nitric oxide (NO) synthase (eNOS) and 2) whether Golgi blockade and eNOS sequestration are observed after hypoxia and senescence. Immunofluorescence data revealed that MCTP-induced “megalocytosis” of pulmonary arterial endothelial cells (PAEC) was accompanied by a loss of eNOS from the plasma membrane, with increased accumulation in the cytoplasm. This cytoplasmic eNOS was sequestered in heterogeneous compartments and partially colocalized with Golgi and endoplasmic reticulum (ER) markers, caveolin-1, NOSTRIN, and ER Tracker, but not Lyso Tracker. Hypoxia and senescence also produced enlarged PAEC, with dysfunctional Golgi and loss of eNOS from the plasma membrane, with sequestration in the cytoplasm. Live-cell imaging of caveolar and cytoplasmic NO with 4,5-diaminofluorescein diacetate (DAF-2DA) as probe showed a marked loss of caveolar NO after MCTP, hypoxia, and senescence. Although ionomycin stimulated DAF-2DA fluorescence in control PAEC, this ionophore decreased DAF-2DA fluorescence in MCTP-treated and senescent PAEC, suggesting localization of eNOS in an aberrant cytoplasmic compartment that was readily discharged by Ca2+-induced exocytosis. Thus monocrotaline, hypoxia, and senescence produce a Golgi blockade in PAEC, leading to sequestration of eNOS away from its functional caveolar location and providing a mechanism for the often-reported reduction in pulmonary arterial NO levels in experimental pulmonary hypertension, despite sustained eNOS protein levels.


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