Targeting Pulmonary Endothelial Hemoglobin α Improves Nitric Oxide Signaling and Reverses Pulmonary Artery Endothelial Dysfunction

Utilizing aortopulmonary vascular graft placement in the fetal lamb, we have developed a model (shunt) of pulmonary hypertension that mimics congenital heart disease with increased pulmonary blood flow. Our previous studies have identified a progressive development of endothelial dysfunction in shunt lambs that is dependent, at least in part, on decreased nitric oxide (NO) signaling. The purpose of this study was to evaluate the possible role of a disruption in carnitine metabolism in shunt lambs and to determine the effect on NO signaling. Our data indicate that at 2 wk of age, shunt lambs have significantly reduced expression ( P < 0.05) of the key enzymes in carnitine metabolism: carnitine palmitoyltransferases 1 and 2 as well as carnitine acetyltransferase (CrAT). In addition, we found that CrAT activity was inhibited due to increased nitration. Furthermore, free carnitine levels were significantly decreased whereas acylcarnitine levels were significantly higher in shunt lambs ( P < 0.05). We also found that alterations in carnitine metabolism resulted in mitochondrial dysfunction, since shunt lambs had significantly decreased pyruvate, increased lactate, and a reduced pyruvate/lactate ratio. In pulmonary arterial endothelial cells cultured from juvenile lambs, we found that mild uncoupling of the mitochondria led to a decrease in cellular ATP levels and a reduction in both endothelial NO synthase-heat shock protein 90 (eNOS-HSP90) interactions and NO signaling. Similarly, in shunt lambs we found a loss of eNOS-HSP90 interactions that correlated with a progressive decrease in NO signaling. Our data suggest that mitochondrial dysfunction may play a role in the development of endothelial dysfunction and pulmonary hypertension and increased pulmonary blood flow.

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Endothelial dysfunction induced by cadmium and mercury and its relationship to hypertension

Current Hypertension Reviews ◽

10.2174/1573402117666210121102405 ◽

2021 ◽

Vol 17 ◽

Author(s):

Airton Cunha Martins ◽

Alessanda Antunes Dos Santos ◽

Ana Carolina B. Almeida Lopes ◽

Anatoly V. Skalny ◽

Michael Aschner ◽

...

Keyword(s):

Public Health ◽

Nitric Oxide ◽

Heavy Metals ◽

Endothelial Dysfunction ◽

Toxic Elements ◽

Health Concern ◽

Public Health Concern ◽

Important Public Health ◽

Nitric Oxide Signaling

: Hypertension is an important public health concern that affects millions globally, leading to a large number of morbidities and fatalities. The etiology of hypertension is complex and multifactorial, and it involves environmental factors including heavy metals. Indeed, cadmium and mercury are toxic elements commonly distributed in the environment which contribute to hypertension. We aimed to assess the role of cadmium and mercury-induced endothelial dysfunction in the development of hypertension. A narrative review was carried out through database searches. In this review, we discussed the critical roles of cadmium and mercury in the etiology of hypertension and provide new insights into potential mechanisms of their effect, focusing primarily on endothelial dysfunction. Although, the mechanisms by which cadmium and mercury induce hypertension have yet to be completely elucidated, evidence for both implicates impaired nitric oxide signaling in their hypertensive etiology.

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C1q/TNF–Related Protein-3 attenuates endothelial dysfunction in diabetic retinopathy via the Nitric Oxide signaling pathway

10.21203/rs.3.rs-26602/v2 ◽

2020 ◽

Keyword(s):

Nitric Oxide ◽

Diabetic Retinopathy ◽

Endothelial Dysfunction ◽

Signaling Pathway ◽

Related Protein ◽

Nitric Oxide Signaling

Abstract The authors have requested that this preprint be withdrawn due to author disagreement.

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High total cholesterol and triglycerides levels increase arginases metabolism, impairing nitric oxide signaling and worsening fetoplacental endothelial dysfunction in gestational diabetes mellitus pregnancies

Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease ◽

10.1016/j.bbadis.2021.166216 ◽

2021 ◽

pp. 166216

Author(s):

S. Contreras-Duarte ◽

C. Claudette ◽

M. Farias ◽

A. Leiva

Keyword(s):

Nitric Oxide ◽

Diabetes Mellitus ◽

Endothelial Dysfunction ◽

Gestational Diabetes ◽

Gestational Diabetes Mellitus ◽

Total Cholesterol ◽

High Total Cholesterol ◽

Nitric Oxide Signaling

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Abstract P060: High Salt Induces An Endothelial HDAC1-stimulating Circulating Factor Leading To Disrupted Renal Microvascular Nitric Oxide Signaling

Hypertension ◽

10.1161/hyp.76.suppl_1.p060 ◽

2020 ◽

Vol 76 (Suppl_1) ◽

Author(s):

Luke S Dunaway ◽

Anthony K Cook ◽

Edward W Inscho ◽

Jennifer Pollock

Keyword(s):

Nitric Oxide ◽

Endothelial Dysfunction ◽

Specific Inhibitor ◽

High Salt ◽

Afferent Arteriole ◽

Sprague Dawley ◽

Salt Diet ◽

Nitric Oxide Signaling ◽

No Signaling

High salt diet (HS) decreases endothelial nitric oxide (NO) signaling as described in human and rodent studies. We have previously shown that inhibition of HDAC1 restores NO signaling in the afferent arteriole of HS fed rats. It remains unknown, however, how HS initiates endothelial dysfunction and activates HDAC1. We first investigated if HS induced endothelial dysfunction is acutely regulated by a circulating factor. To test this, male Sprague Dawley rats were fed normal salt diet (NS; 0.49% NaCl) or 2 weeks of HS (4.0% NaCl). Afferent arteriole vasoconstrictor responses to the NOS inhibitor, L-NAME, were monitored using the in vitro, blood perfused juxtamedullary nephron preparation. Perfusing arterioles from NS fed rats with HS blood blunted constriction to L-NAME (88 ± 1% of Con) compared to perfusing with NS blood (76 ± 2% of Con; P=0.0003), but not completely as seen in arterioles from HS fed rats perfused with HS blood (96 ± 2% of Con; P=0.0095). HS arterioles perfused with NS blood had similar L-NAME-induced constriction (75 ± 2% of Con) compared to arterioles from NS fed rats perfused with NS blood (P=0.9107). These results suggest HS induces endothelial function through an acute-acting circulating factor. This was not due to increased plasma arginase activity (NS: 7.96 ± 3.73 U/L vs HS: 5.42 ± 1.83 U/L P=0.5813) which competes with NO synthase 3 for arginine, nor was it due to decreased superoxide scavenging capacity of the plasma (NS: 7.96 ± 3.73 U/L vs HS: 5.42 ± 1.83 U/L P=0.5813) as measured by a cytochrome c reduction based assay. We then investigated if HS increased endothelial HDAC1 activity. Renal endothelial cells were isolated via magnetic activated cell sorting from NS and HS fed rats and incubated in plasma from the same rat. HDAC1 activity was monitored as the MS-275 (HDAC1 specific inhibitor) inhibitable portion of total HDAC activity. We found HS significantly increased renal endothelium HDAC1 activity (NS: 0.38 ± 0.03 pmol/min vs HS:0.94 ± 0.19 pmol/min, P=0.01). We conclude that HS disruption of renal microvascular NO signaling is initiated by a circulating factor(s) that is dependent upon increased endothelial HDAC1 activity.

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Abstract 12185: Restoration of Autophagy in Endothelial Cells From Patients With Diabetes Improves Nitric Oxide Signaling

Circulation ◽

10.1161/circ.130.suppl_2.12185 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Jessica L Fetterman ◽

Nir Flint ◽

Monica Holbrook ◽

Erika A Linder ◽

Brittany D Berk ◽

...

Keyword(s):

Nitric Oxide ◽

Endothelial Cells ◽

Endothelial Dysfunction ◽

Vascular Function ◽

Diabetic Patients ◽

Autophagic Flux ◽

Compensatory Response ◽

Nitric Oxide Signaling ◽

Patients With Diabetes ◽

No Signaling

Diabetes is associated with oxidative stress and decreased nitric oxide bioactivity in the vasculature. Autophagy is a critical multistep pathway that eliminates damaged proteins and organelles from the cell. Emerging evidence suggests impaired autophagy in non-vascular tissues contributes to the pathogenesis of diabetes. We hypothesized that impaired autophagy contributes to endothelial dysfunction associated with diabetes in humans. We measured vascular function and autophagy markers in freshly isolated endothelial cells (ECs) from patients with diabetes and non-diabetic controls. Diabetes was associated with endothelial dysfunction characterized by lower brachial artery flow-mediated dilation and impaired activation of eNOS by insulin in ECs. ECs from diabetic patients had higher levels of p62 (Figure), a protein that accumulates with reduced autophagic flux. Measures of autophagy initiation including rapamycin stimulation, beclin 1 levels, and LC3 puncta were not different. Global activation of autophagy with spermidine reversed endothelial dysfunction in freshly isolated ECs from diabetic patients (Figure). In ECs from controls, inhibiting autophagy with bafilomycin impaired eNOS activation confirming that intact autophagy promotes NO signaling. Evidence from cultured endothelial cells in high glucose conditions suggested that lysosomal function is intact as measured by lysosomal number and acidification. Blocking the terminal step of autophagy with bafilomycin in ECs from diabetics led to a further accumulation of p62, suggesting intact but insufficient levels of autophagy. Lamp2a, which facilitates the merger of autophagosomes and lysosomes, was higher in diabetic cells, possibly reflecting a compensatory response to reduced flux. These findings provide evidence for inadequate autophagic flux in ECs from diabetic patients that contributes to impaired NO signaling and may be a target for therapy of diabetic vascular disease.

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