Clinically relevant endothelial nitric oxide synthase polymorphisms and their impact on drug response

Live to die another day: novel insights may explain the pathophysiology behind smoker's paradox in SARS-CoV-2 infection

The severe acute respiratory coronavirus 2 (SARS-CoV-2) infection demonstrates a highly variable and unpredictable course. Several reports have claimed a smoker's paradox in coronavirus disease 2019 (COVID-19), in line with previous suggestions that smoking is associated with better survival after acute myocardial infarction and appears protective in preeclampsia. Several plausible physiological explanations exist accounting for the paradoxical observation of smoking engendering protection against SARS-CoV-2 infection. In this review, we delineate novel mechanisms whereby smoking habits and smokers' genetic polymorphism status affecting various nitric oxide (NO) pathways (endothelial NO synthase, cytochrome P450 (CYP450), erythropoietin receptor (EPOR); β-common receptor (βcR)), along with tobacco smoke modulation of microRNA-155 and aryl-hydrocarbon receptor (AHR) effects, may be important determinators of SARS-CoV-2 infection and COVID-19 course. While transient NO bioavailability increase and beneficial immunoregulatory modulations through the above-mentioned pathways using exogenous, endogenous, genetic and/or therapeutic modalities may have direct and specific, viricidal SARS-CoV-2 effects, employing tobacco smoke inhalation to achieve protection equals self-harm. Tobacco smoking remains the leading cause of death, illness, and impoverishment.

A protective erythropoietin evolutionary landscape, NLRP3 inflammasome regulation, and multisystem inflammatory syndrome in children

The low incidence of pediatric severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and the associated multisystem inflammatory syndrome (MIS-C) lack a unifying pathophysiological explanation, impeding effective prevention and therapy. Activation of the NACHT, LRR, and PYD domains-containing protein (NLRP) 3 inflammasome in SARS-CoV-2 with perturbed regulation in MIS-C, has been reported. We posit that, early age physiological states and genetic determinants, such as certain polymorphisms of renin-angiotensin aldosterone system (RAAS) molecules, promote a controlled RAAS hyperactive state, and form an evolutionary landscape involving an age-dependent erythropoietin (EPO) elevation, mediating ancestral innate immune defenses that, through appropriate NLRP3 regulation, mitigate tissue injury and pathogen invasion. SARS-CoV-2-induced downregulation of angiotensin-converting enzyme (ACE)2 expression in endothelial cells (EC), impairment of endothelial nitric oxide (NO) synthase (eNOS) activity and downstream NO bioavailability, may promote a hyperactive RAAS with elevated angiotensin II and aldosterone that, can trigger, and accelerate NLRP3 inflammasome activation, while EPO-eNOS/NO abrogate it. Young age and a protective EPO evolutionary landscape may successfully inhibit SARS-CoV-2 and contain NLRP3 inflammasome activation. By contrast, increasing age and falling EPO levels, in genetically susceptible children with adverse genetic variants and co-morbidities, may lead to unopposed RAAS hyperactivity, NLRP3 inflammasome dysregulation, severe endotheliitis with pyroptotic cytokine storm, and development of autoantibodies, as already described in MIS-C. Our haplotype estimates, predicted from allele frequencies in population databases, are in concordance with MIS-C incidence reports in Europeans but indicate lower risks for Asians and African Americans. Targeted Mendelian approaches dissecting the influence of relevant genetic variants are needed.

Endothelial nitric oxide synthase gene polymorphism (786T/C) in childhood acute lymphoblastic leukemia survivors

OBJECTIVES

To detect eNOS gene polymorphism and its relation to cardiovascular complications in pediatric acute lymphoblastic leukemia (ALL) survivors.

METHODS

CBC, renal and liver function tests, lipid profile, Carotid artery Intima Media Thickness (CIMT), and Brachial artery Intima Media Thickness (BIMT). eNOS gene polymorphism was done in 40 childhood ALL survivors and 40 controls.

RESULTS

There was no significant difference between survivors and control groups regarding 786 T/C polymorphism. There was a significant increase in serum cholesterol, TGs, LDL, VLDL, and HbA1c in the TC and CC group more than in the TT group, while there was a significant decrease in serum HDL in the TC and CC group more than in the TT group. There was no significant difference as regards echocardiography findings between different polymorphisms of 786 T/C, but there was a significant difference between 786 T/C groups with regard to the carotid and brachial arteries intima media thickness (IMT) measurements being significantly higher in the TC and CC group more than in the TT group.

CONCLUSION

Carotid and brachial arteries intima media thickness measurements were higher in the survivors when compared to healthy controls. eNOS gene polymorphism may play a role in modifying or developing CVD in pediatric ALL survivors.

The influence of renin angiotensin aldosterone system (RAAS), endothelial nitric oxide synthase (eNOS) and erythropoietin (EPO) on COVID-19 complications

Certain aspects of the renin-angiotensin-aldosterone system (RAAS) have eluded deserved attention such as the role of erythropoietin (EPO) and nitric oxide (NO) both of which appear to significantly modulate COVID-19 disease course. Furthermore, renin-angiotensin-aldosterone system (RAAS) and endothelial NO synthase (eNOS) genetic polymorphisms additionally impact on EPO and NO homeostasis and have extensive implications on pharmacological disease management.

Candidate Gene of NOS3, MMP3, AGT, and AGT1R and Pathway Analyses for Platelet Reactivity and Clinical Outcomes of Repeat Revascularization After First PCI in Chinese Patients

PURPOSE

Major disadvantages of the percutaneous coronary intervention (PCI) are the high occurrence of repeat revascularization due to restenosis and disease progression. The current study aimed to identify indicators that can predict the risk of repeat revascularization.

METHODS

A total of 143 patients who underwent PCI and had genetic test results were enrolled. We retrospectively reviewed their medical records after the first PCI. P2Y12 reaction unit (PRU) test results were obtained by VerifyNow; 4 candidate genes (NOS3, MMP3, AGT, and AGT1R) and 380 genes related to platelet activation-related processes and clopidogrel activity were selected for analysis. Repeat revascularization and in-stent restenosis (ISR) were used as clinical outcomes, and PRU and ADP aggregation rates were used as platelet function outcomes in analysis.

RESULTS

After the first PCI, the incidence of repeat revascularization at 18, 30, and 42 months was 14.1% (20/142), 17.5% (24/137), and 39.7% (31/78), respectively. In the candidate gene analysis, rs7830 (NOS3) was associated with both ADP aggregation rate and 18- and 30-month ISR, and rs 62,275,847 (AGTR1) was associated with both ADP aggregation rate and 30-month ISR. In the pathway, gene-set analysis, the linkage rs471683 and rs7785386 of GNAI1|GNAT3 were associated with PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 30 months. Rs1715389 of GNAI1|GNAT3 was associated with both PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 30 months. Rs7313458 of ITPR2 was associated with PRU and ADP aggregation rate, 18-month and 30-month ISR, and repeat revascularization within 18 months.

CONCLUSIONS

The genetic polymorphisms of rs7830 (NOS3), rs62275874 (AGTR1), linkage rs471683 and rs7785386 (GNAI1|GNAT3), rs1715389 (GNAI1|GNAT3), and rs7313458 (ITPR2) may lead to an increased risk of in-stent restenosis and revascularization after the first PCI in Chinese patients by affecting the efficacy of clopidogrel. The above six SNP may be used as potential genetic biomarkers for high risk of in-stent restenosis and revascularization after the first PCI in Chinese patients.

A multicenter case-control study of the effect of e-nos VNTR polymorphism on upper gastrointestinal hemorrhage in NSAID users

Bleeding in non-steroidal anti-inflammatory drug (NSAID) users limited their prescription. This first multicenter full case–control study (325 cases and 744 controls), explored the association of e-NOS intron 4 variable number tandem repeat (VNTR) polymorphism with upper gastrointestinal hemorrhage (UGIH) in NSAID exposed and unexposed populations and assessed any interaction between this polymorphism and NSAIDs. NSAID users carrying e-NOS intron 4 wild type genotype or VNTR polymorphism have higher odds of UGIH than those unexposed to NSAIDs [Odds Ratio (OR): 6.62 (95% Confidence Interval (CI): 4.24, 10.36) and OR: 5.41 (95% CI 2.62, 11.51), respectively], with no effect modification from VNTR polymorphism-NSAIDs interaction [Relative Excess Risk due to Interaction (RERI): −1.35 (95% CI −5.73, 3.03); Synergism Index (S): 0.77 (95% CI 0.31, 1.94)]. Similar findings were obtained for aspirin exposure. Non-aspirin NSAID users who carry e-NOS intron 4 VNTR polymorphism have lower odds of UGIH [OR: 4.02 (95% CI 1.85, 8.75) than those users with wild type genotype [OR: 6.52 (95% CI 4.09, 10.38)]; though the interaction estimates are not statistically significant [RERI: −2.68 (95% CI −6.67, 1.31); S: 0.53 (95% CI 0.18, 1.55)]. This exploratory study suggests that the odds of UGIH in NSAID or aspirin users does not modify according to patient´s e-NOS intron 4 genotype.

Acute Exercise, Plasma Nitric Oxide, and Blood Pressure in Older Adults With Different Levels of Training Status: The Influence of Polymorphisms of Endothelial Nitric Oxide Synthase

BACKGROUND

This study aimed to analyze the acute effect of physical exercise on nitric oxide concentration and blood pressure (BP) in older adults with different levels of training status (TS) and verified the influence of endothelial nitric oxide synthase polymorphisms on these variables.

METHODS

A total of 145 older adults were divided into good TS (G1) and weak TS (G2). Participants were subjected to a 40-minute treadmill walk (40%-60% of maximum oxygen consumption) with BP measurements and blood collections for plasma nitrite and oxidative stress biomarkers at pretest and posttest moments. Data were analyzed by 2-way repeated-measures with Sidak post hoc test (P < .05) and multivariate linear analysis.

RESULTS

After acute exercise, G2 showed an increase in oxidative stress biomarkers (P = .008), and both groups showed an increase in systolic BP (P < .001). Polymorphisms 894G > T and intron 4b/a had no association with nitrite and BP. However, -786T > C polymorphism showed an association with reduced systolic and diastolic BP (TT genotype) and increased diastolic BP (TC genotype). Higher TS level was also associated with lower BP.

CONCLUSION

The maintenance of good TS levels may have a protective effect on cardiovascular risks regardless of the genetic profile.