The adverse cardiopulmonary phenotype of caveolin-1 deficient mice is mediated by a dysfunctional endothelium

Wunderlich, Carsten; Schober, Kristin; Schmeißer, Alexander; Heerwagen, Christian; Tausche, Anne‐Kathrin; Steinbronn, Nadine; Brandt, Aljoscha; Kasper, Michael; Schwencke, Carsten; Braun-Dullaeus, Ruediger C.; Strasser, Ruth H.

doi:10.1016/j.yjmcc.2008.02.275

Cited by 50 publications

(39 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar role for caveolin-1 in activation of Rac1, increased ROS production, and vascular hypertrophy after angiotensin II type 1 receptor activation has been suggested in vascular smooth muscle cells (17). Although both epithelial and endothelial cells express caveolin-1 (44,45), there is substantial evidence that lack of endothelial caveolin-1 plays a major role in the pathophysiology observed in caveolin-1 knock-out mice (46,47). Therefore, it is reasonable to speculate that the pulmonary effects we observe with hyperoxia treatment of mice are through a preferential endothelial-dependent, rather than epithelial-dependent, mechanism (46,47).…”

Section: And P47mentioning

confidence: 86%

Dynamin 2 and c-Abl Are Novel Regulators of Hyperoxia-mediated NADPH Oxidase Activation and Reactive Oxygen Species Production in Caveolin-enriched Microdomains of the Endothelium

Singleton

Pendyala

Горшкова

et al. 2009

Journal of Biological Chemistry

View full text Add to dashboard Cite

Reactive oxygen species (ROS) generation, particularly by the endothelial NADPH oxidase family of proteins, plays a major role in the pathophysiology associated with lung inflammation, ischemia/reperfusion injury, sepsis, hyperoxia, and ventilatorassociated lung injury. We examined potential regulators of ROS production and discovered that hyperoxia treatment of human pulmonary artery endothelial cells induced recruitment of the vesicular regulator, dynamin 2, the non-receptor tyrosine kinase, c-Abl, and the NADPH oxidase subunit, p47 phox , to caveolin-enriched microdomains (CEMs). Silencing caveolin-1 (which blocks CEM formation) and/or c-Abl expression with small interference RNA inhibited hyperoxia-mediated tyrosine phosphorylation and association of dynamin 2 with p47 phox and ROS production. In addition, treatment of human pulmonary artery endothelial cells with dynamin 2 small interfering RNA or the dynamin GTPase inhibitor, Dynasore, attenuated hyperoxia-mediated ROS production and p47 phox recruitment to CEMs. Using purified recombinant proteins, we observed that c-Abl tyrosine-phosphorylated dynamin 2, and this phosphorylation increased p47 phox /dynamin 2 association (change in the dissociation constant (K d ) from 85.8 to 6.9 nM). Furthermore, exposure of mice to hyperoxia increased ROS production, c-Abl activation, dynamin 2 association with p47 phox , and pulmonary leak, events that were attenuated in the caveolin-1 knock-out mouse confirming a role for CEMs in ROS generation. These results suggest that hyperoxia induces c-Abl-mediated dynamin 2 phosphorylation required for recruitment of p47 phox to CEMs and subsequent ROS production in lung endothelium.Vascular endothelial cell (EC) 2 barrier integrity is critical to normal vessel homeostasis with defects in the EC barrier contributing to inflammation, tumor angiogenesis, atherosclerosis, and acute lung injury (1). The generation of reactive oxygen species (ROS) in the vasculature plays a major role in EC activation and barrier function (2). Of the several potential sources of ROS in the vasculature, the endothelial NADPH oxidase family of proteins is a major contributor of ROS, and accumulation of ROS is associated with lung inflammation, ischemiareperfusion injury, sepsis, hyperoxia, and ventilator-associated lung injury (3). Activation of phagocytic NADPH oxidase requires the assembly of the cytosolic p47 phox , p67 phox , p40 phox , and Rac2 with membrane-associated cytochrome b 558 reductase, which consists of p22 phox and Nox2 (gp91 phox ). Vascular cells express similar subcomponents to phagocytic NADPH oxidase subunits, including Rac1, p47 phox , and Nox2 (2, 3). We have recently demonstrated that exposure of human pulmonary artery endothelial cells (HPAECs) to hyperoxia (95% O 2 ) increases the ROS production that is dependent on NADPH oxidase activation and independent of the mitochondrial electron transport or xanthine/xanthine oxidase systems (4).Regulation of NADPH oxidase activation in phagocytes requires serine phosphorylation of t...

show abstract

Section: And P47mentioning

confidence: 86%

Dynamin 2 and c-Abl Are Novel Regulators of Hyperoxia-mediated NADPH Oxidase Activation and Reactive Oxygen Species Production in Caveolin-enriched Microdomains of the Endothelium

Singleton

Pendyala

Горшкова

et al. 2009

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Studies have suggested that eNOS uncoupling may be sufficient to increase the production of superoxide in Cav1 -/-lungs and may thus mediate PH (40). Treatment of neonatal Cav1 -/-mice with tetrahydrobiopterin, an essential cofactor for all 3 NOS isoforms (41,42), prevented PH (40).…”

Section: Discussionmentioning

confidence: 99%

Persistent eNOS activation secondary to caveolin-1 deficiency induces pulmonary hypertension in mice and humans through PKG nitration

et al. 2009

View full text Add to dashboard Cite

Pulmonary hypertension (PH) is an unremitting disease defined by a progressive increase in pulmonary vascular resistance leading to right-sided heart failure. Using mice with genetic deletions of caveolin 1 (Cav1) and eNOS (Nos3), we demonstrate here that chronic eNOS activation secondary to loss of caveolin-1 can lead to PH. Consistent with a role for eNOS in the pathogenesis of PH, the pulmonary vascular remodeling and PH phenotype of Cav1 -/-mice were absent in Cav1 -/-Nos3 -/-mice. Further, treatment of Cav1 -/-mice with either MnTMPyP (a superoxide scavenger) or l-NAME (a NOS inhibitor) reversed their pulmonary vascular pathology and PH phenotype. Activation of eNOS in Cav1 -/-lungs led to the impairment of PKG activity through tyrosine nitration. Moreover, the PH phenotype in Cav1 -/-lungs could be rescued by overexpression of PKG-1. The clinical relevance of the data was indicated by the observation that lung tissue from patients with idiopathic pulmonary arterial hypertension demonstrated increased eNOS activation and PKG nitration and reduced caveolin-1 expression. Together, these data show that loss of caveolin-1 leads to hyperactive eNOS and subsequent tyrosine nitration-dependent impairment of PKG activity, which results in PH. Thus, targeting of PKG nitration represents a potential novel therapeutic strategy for the treatment of PH.

show abstract

“…Interestingly, these mice also have severe heart failure and lung fibrosis; treatment with BH 4 is able to rescue these animals, resulting in substantially improved heart and lung function (27). These authors argue that the eNOS-mediated dysfunction may be caused by an imbalance between cellular BH 4 levels and eNOS, leading to eNOS-dependent ROS generation.…”

Section: Discussionmentioning

confidence: 99%

Suppression of eNOS-derived superoxide by caveolin-1: a biopterin-dependent mechanism

Karuppiah¹,

Druhan²,

Chen

et al. 2011

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Karuppiah K, Druhan LJ, Chen CA, Smith T, Zweier JL, Sessa WC, Cardounel AJ. Suppression of eNOS-derived superoxide by caveolin-1: a biopterin-dependent mechanism. Am J Physiol Heart Circ Physiol 301: H903-H911, 2011. First published July 1, 2011; doi:10.1152/ajpheart.00936.2010.-In the vasculature, nitric oxide (NO) is generated by endothelial NO synthase (eNOS) in a calcium/ calmodulin-dependent reaction. In the absence of the requisite eNOS cofactor tetrahydrobiopterin (BH4), NADPH oxidation is uncoupled from NO generation, leading to the production of superoxide. Although this phenomenon is apparent with purified enzyme, cellular studies suggest that formation of the BH4 oxidation product, dihydrobiopterin, is the molecular trigger for eNOS uncoupling rather than BH4 depletion alone. In the current study, we investigated the effects of both BH4 depletion and oxidation on eNOS-derived superoxide production in endothelial cells in an attempt to elucidate the molecular mechanisms regulating eNOS oxidase activity. Results demonstrated that pharmacological depletion of endothelial BH4 does not result in eNOS oxidase activity, whereas BH4 oxidation gave rise to significant eNOS-oxidase activity. These findings suggest that the endothelium possesses regulatory mechanisms, which prevent eNOS oxidase activity from pterin-free eNOS. Using a combination of gene silencing and pharmacological approaches, we demonstrate that eNOS-caveolin-1 association is increased under conditions of reduced pterin bioavailability and that this sequestration serves to suppress eNOS uncoupling. Using small interfering RNA approaches, we demonstrate that caveolin-1 gene silencing increases eNOS oxidase activity to 85% of that observed under conditions of BH 4 oxidation. Moreover, when caveolin-1 silencing was combined with a pharmacological inhibitor of AKT, BH 4 depletion increased eNOS-derived superoxide to 165% of that observed with BH 4 oxidation. This study identifies a critical role of caveolin-1 in the regulation of eNOS uncoupling and provides new insight into the mechanisms through which disease-associated changes in caveolin-1 expression may contribute to endothelial dysfunction.endothelial nitric oxide synthase; endothelium; oxidative stress; tetrahydrobiopterin ENDOTHELIUM-DERIVED NITRIC oxide (NO) is a potent vasodilator that plays a critical role in maintaining vascular homeostasis through its antiatherogenic and antiproliferative effects on the vascular wall. Reduced NO bioavailability is a key determinant of endothelial dysfunction and has been demonstrated to play a central role in the increased cardiovascular risks associated with metabolic syndrome (3, 26). Endothelial dysfunction has been observed in pre-diabetic stages of insulin resistance and subsequently contributes to smooth muscle cell proliferation and platelet and leukocyte adhesion as well as atherogenesis (4,10,22). Impaired endothelial function is apparent in experimental diabetes and in diabetic patients despite the fact that endothelial NO synthase (eNOS) e...

show abstract

The adverse cardiopulmonary phenotype of caveolin-1 deficient mice is mediated by a dysfunctional endothelium

Cited by 50 publications

References 32 publications

Dynamin 2 and c-Abl Are Novel Regulators of Hyperoxia-mediated NADPH Oxidase Activation and Reactive Oxygen Species Production in Caveolin-enriched Microdomains of the Endothelium

Dynamin 2 and c-Abl Are Novel Regulators of Hyperoxia-mediated NADPH Oxidase Activation and Reactive Oxygen Species Production in Caveolin-enriched Microdomains of the Endothelium

Persistent eNOS activation secondary to caveolin-1 deficiency induces pulmonary hypertension in mice and humans through PKG nitration

Suppression of eNOS-derived superoxide by caveolin-1: a biopterin-dependent mechanism

Contact Info

Product

Resources

About