The phosphorylation state of eNOS modulates vascular reactivity and outcome of cerebral ischemia in vivo

Atochin, Dmitriy N.; Wang, Annie; Liu, Victor W.T.; Critchlow, Jeffrey D.; Dantas, Ana Paula; Looft‐Wilson, Robin; Murata, Takahisa; Salomone, Salvatore; Shin, Hwa Kyoung; Ayata, Cenk; Moskowitz, Michael A.; Michel, Thomas; Sessa, William C.; Huang, Paul L.

doi:10.1172/jci29877

Cited by 149 publications

(142 citation statements)

References 33 publications

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“…Phosphorylation of eNOS at S1179 participates in the activation of eNOS with both agonist stimulation and shear stress (5,14) and has been found to be important for agonist-induced nitric oxide-dependent dilation (1). In the present study, both basal eNOS expression and the proportion of S1179 phosphorylation were downregulated in HHcy mesenteric arteries in vivo, suggesting that the basal ability to produce nitric oxide and the response to basal shear stress may be impaired.…”

Section: Discussionmentioning

confidence: 46%

Chronic diet-induced hyperhomocysteinemia impairs eNOS regulation in mouse mesenteric arteries

Looft‐Wilson¹,

Ashley²,

Billig³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

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Looft-Wilson RC, Ashley BS, Billig JE, Wolfert MR, Ambrecht LA, Bearden SE. Chronic diet-induced hyperhomocysteinemia impairs eNOS regulation in mouse mesenteric arteries. Am J Physiol Regul Integr Comp Physiol 295: R59 -R66, 2008. First published April 30, 2008 doi:10.1152/ajpregu.00833.2007.-Hyperhomocysteinemia (HHcy) impairs endothelium-dependent vasodilation by increasing reactive oxygen species, thereby reducing nitric oxide (NO ⅐ ) bioavailability. It is unclear whether reduced expression or function of the enzyme that produces NO ⅐ , endothelial nitric oxide synthase (eNOS), also contributes. It is also unclear whether resistance vessels that utilize both NO ⅐ and non-NO ⅐ vasodilatory mechanisms, undergo alteration of non-NO ⅐ mechanisms in this condition. We tested these hypotheses in male C57BL/6 mice with chronic HHcy induced by 6-wk high methionine/low-B vitamin feeding (Hcy: 89.2 Ϯ 49.0 M) compared with age-matched controls (Hcy: 6.6 Ϯ 1.9 M), using first-order mesenteric arteries. Dilation to ACh (10 Ϫ9 -10 Ϫ4 M) was measured in isolated, cannulated, and pressurized (75 mmHg) arteries with and without N G -nitro-L-arginine methyl ester (L-NAME) (10 Ϫ4 M) and/or indomethacin (10 Ϫ5 M) to test endothelium-dependent dilation and non-NO ⅐ -dependent dilation, respectively. The time course of dilation to ACh (10 Ϫ4 M) was examined to compare the initial transient dilation due to non-NO ⅐ , non-prostacyclin mechanism and the sustained dilation due to NO ⅐ . These experiments indicated that endothelium-dependent dilation was attenuated (P Ͻ 0.05) in HHcy arteries due to downregulation of only NO ⅐ -dependent dilation. Western blot analysis indicated significantly less (P Ͻ 0.05) basal eNOS and phospho-S1179-eNOS/eNOS in mesenteric arteries from HHcy mice but no difference in phospho-T495-eNOS/eNOS. S1179 eNOS phosphorylation was also significantly less in these arteries when stimulated with ACh ex vivo or in situ. Real-time PCR indicated no difference in eNOS mRNA levels. In conclusion, chronic dietinduced HHcy in mice impairs eNOS protein expression and phosphorylation at S1179, coincident with impaired NO ⅐ -dependent dilation, which implicates dysfunction in eNOS post-transcriptional regulation in the impaired endothelium-dependent vasodilation and microvascular disease that is common with HHcy.

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Section: Discussionmentioning

confidence: 46%

Chronic diet-induced hyperhomocysteinemia impairs eNOS regulation in mouse mesenteric arteries

Looft‐Wilson¹,

Ashley²,

Billig³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Thus, our results indicate that rapamycin acts as a vasodilator, in agreement with prior reports. 63,64 A link between the inhibition of mTOR and the activation of eNOS had been suggested by studies showing that Akt, which phosphorylates eNOS and increases NO production, 65 can be activated by rapamycin treatment, 66,67 and conversely, that activation of mTOR results in Akt inhibition. 66,68 Restoration of vascular density in AD mice required NO synthase activity, suggesting that mTOR has a critical role in the inhibition of NO release in brain vascular endothelium during the progression of AD-like disease in mice ( Figure 5).…”

Section: Discussionmentioning

confidence: 99%

Chronic Rapamycin Restores Brain Vascular Integrity and Function Through NO Synthase Activation and Improves Memory in Symptomatic Mice Modeling Alzheimer’s Disease

Lin¹,

Zheng

Halloran

et al. 2013

J Cereb Blood Flow Metab

181

204

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Vascular pathology is a major feature of Alzheimer's disease (AD) and other dementias. We recently showed that chronic administration of the target-of-rapamycin (TOR) inhibitor rapamycin, which extends lifespan and delays aging, halts the progression of AD-like disease in transgenic human (h)APP mice modeling AD when administered before disease onset. Here we demonstrate that chronic reduction of TOR activity by rapamycin treatment started after disease onset restored cerebral blood flow (CBF) and brain vascular density, reduced cerebral amyloid angiopathy and microhemorrhages, decreased amyloid burden, and improved cognitive function in symptomatic hAPP (AD) mice. Like acetylcholine (ACh), a potent vasodilator, acute rapamycin treatment induced the phosphorylation of endothelial nitric oxide (NO) synthase (eNOS) and NO release in brain endothelium. Administration of the NOS inhibitor L-NG-Nitroarginine methyl ester reversed vasodilation as well as the protective effects of rapamycin on CBF and vasculature integrity, indicating that rapamycin preserves vascular density and CBF in AD mouse brains through NOS activation. Taken together, our data suggest that chronic reduction of TOR activity by rapamycin blocked the progression of AD-like cognitive and histopathological deficits by preserving brain vascular integrity and function. Drugs that inhibit the TOR pathway may have promise as a therapy for AD and possibly for vascular dementias.

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“…This transgenic mouse was then crossed into the eNOS −/− background. This model has been previously described in detail (43). Male mice age 14-16 wk were used during the course of this present study.…”

Section: Methodsmentioning

confidence: 99%

Hydrogen sulfide cytoprotective signaling is endothelial nitric oxide synthase-nitric oxide dependent

King

Polhemus

Bhushan

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

325

312

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Previous studies have demonstrated that hydrogen sulfide (H 2 S) protects against multiple cardiovascular disease states in a similar manner as nitric oxide (NO). H 2 S therapy also has been shown to augment NO bioavailability and signaling. The purpose of this study was to investigate the impact of H 2 S deficiency on endothelial NO synthase (eNOS) function, NO production, and ischemia/reperfusion (I/R) injury. We found that mice lacking the H 2 S-producing enzyme cystathionine γ-lyase (CSE) exhibit elevated oxidative stress, dysfunctional eNOS, diminished NO levels, and exacerbated myocardial and hepatic I/R injury. In CSE KO mice, acute H 2 S therapy restored eNOS function and NO bioavailability and attenuated I/R injury. In addition, we found that H 2 S therapy fails to protect against I/R in eNOS phosphomutant mice (S1179A). Our results suggest that H 2 S-mediated cytoprotective signaling in the setting of I/R injury is dependent in large part on eNOS activation and NO generation.eNOS uncoupling | myocardial infarction | cystathionase | Cth | nitrite H ydrogen sulfide (H 2 S), historically known for its odorous smell and toxicity at high concentrations, has recently been classified as a physiological signaling molecule with robust cytoprotective actions in multiple organ systems (1-3). H 2 S is produced enzymatically in mammalian tissues by three different enzymes: cystathionine γ-lyase (CSE), cystathionine beta-synthase (CBS), and 3-mercatopyruvate sulfurtransferase (3-MST). CSE, involved in the cysteine biosynthesis pathway, coordinates with L-cystine to produce H 2 S within the vasculature and is known to regulate blood pressure, modulate cellular metabolism, promote angiogenesis, regulate ion channels, and mitigate fibrosis and inflammation (4). Endothelial nitric oxide synthase (eNOS) catalyzes the production of nitric oxide (NO) from L-arginine within the endothelium to regulate vascular tone via cGMP signaling in vascular smooth muscle, mitochondrial respiration, platelet function, inflammation, and angiogenesis. The biological profiles of H 2 S and NO are similar, and both molecules are known to protect cells against various injurious states that result in organ injury. Although H 2 S and NO are thought to modulate independent signaling pathways, there is limited evidence of cross-talk between these two molecules (5, 6).H 2 S therapeutics and endogenous overexpression of CSE have been shown to attenuate ischemia/reperfusion (I/R) injury (7,8). Similarly, NO therapy and eNOS gene overexpression are also protective in ischemic disease states (9). Given the potent antioxidant actions of H 2 S (10, 11) and the effects of exogenous H 2 S therapy on NO bioavailability (5, 8), we investigated the effects of genetic deletion of the cystathionase gene (Cth, i.e., CSE KO) on the regulation of eNOS function and NO bioavailability. ResultsSulfide Levels are Reduced in CSE KO Mice. Whole blood and heart specimens were collected from WT and CSE KO mice to measure H 2 S levels using a high-sensitivity gas chromato...

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The phosphorylation state of eNOS modulates vascular reactivity and outcome of cerebral ischemia in vivo

Cited by 149 publications

References 33 publications

Chronic diet-induced hyperhomocysteinemia impairs eNOS regulation in mouse mesenteric arteries

Chronic diet-induced hyperhomocysteinemia impairs eNOS regulation in mouse mesenteric arteries

Chronic Rapamycin Restores Brain Vascular Integrity and Function Through NO Synthase Activation and Improves Memory in Symptomatic Mice Modeling Alzheimer’s Disease

Hydrogen sulfide cytoprotective signaling is endothelial nitric oxide synthase-nitric oxide dependent

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