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Background: Endothelial dysfunction is a forerunner of atherosclerosis, leading to cardiovascular disease, and albuminuria is a marker of endothelial dysfunction. Circulating levels of microRNAs are emerging as potential biomarkers for cardiovascular disease. Here we estimate the predictive value of a plasma microRNAs signature associated with albuminuria in the incidence of cardiovascular events., Methods: Plasma microRNAs quantified in hypertensive patients by next generation sequencing were validated in a cohort of patients and controls by real-time quantitative PCR. The microRNAs found to be associated with albuminuria were analysed for their prognostic value in predicting cardiovascular events incidence on a retrospective, population-based study (Hortega Study), using Cox proportional hazard models., Results: A plasma microRNA profile was identified in the discovery cohort (n = 48) associated with albuminuria and three microRNAs (miR-126-3p, miR-1260b and miR-374a-5p) were confirmed in the validation cohort (n = 98). The microRNA signature discriminates urinary albumin excretion at baseline (n = 1025), and predicts the incidence of cardiovascular events and coronary heart disease and stroke in a general population retrospective study within a 14-year follow-up (n = 926). High miR-126-3p levels were associated with a shorter time free of both cardiovascular events (HR=1.48, (1.36-1.62), p < 0.0001), as well as coronary artery disease and stroke combined (HR=2.49, (2.19-2.83), p < 0.0001)., Conclusions: An increased plasma microRNAs profile was identified in hypertensive patients with albuminuria. Increased miR-126-3p suggest it may serve as a prognostic marker for cardiovascular events in a long-term general population. Further studies will assess the potential role of miR-126-3p as a guide for the status of endothelial dysfunction., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023. Published by Elsevier B.V.)

Urinary albumin excretion (UAE) is a marker of cardiovascular risk and renal damage in hypertension. MicroRNAs (miRNAs) packaged into exosomes function as paracrine effectors in cell communication and the kidney is not exempt. This study aimed to state an exosomal miRNA profile/signature associated to hypertension with increased UAE and the impact of profibrotic TGF-β1 (transforming growth factor β1) on exosomes miRNA release. Therefore, exosomes samples from patients with hypertension with/without UAE were isolated and characterized. Three individual and unique small RNA libraries from each subject were prepared (total plasma, urinary, and plasma-derived exosomes) for next-generation sequencing profiling. Differentially expressed miRNAs were over-represented in Kyoto Encyclopedia of Genes and Genomes pathways, and selected miRNAs were validated by real-time quantitative polymerase chain reaction in a confirmation cohort. Thus, a signature of 29 dysregulated circulating miRNAs was identified in UAE hypertensive subjects, regulating 21 pathways. Moreover, changes in the levels of 4 exosomes-miRNAs were validated in a confirmation cohort and found associated with albuminuria. In particular miR-26a, major regulator of TGF-β signaling, was found downregulated in both type of exosomes when compared with healthy controls and to hypertension normoalbuminurics ( P <0.01). Similarly, decreased miR-26a levels were found in podocyte-derived exosomes after TGF-β stress. Our results revealed an exosomes miRNA signature associated to albuminuria in hypertension. In particular, exosomes miR-26a seemed to play a key role in the regulation of TGF-β, a relevant effector in podocyte damage. These findings support the use of exosomes miRNAs as biomarkers of cardiovascular risk progression and therapeutic tools in early kidney damage.

Objective: Hypertension-induced podocyte damage and the relationship with UAE is analyzed in diabetic and nondiabetic participants., Patients and Methods: Sixty-four hypertensive patients, 30 diabetics, with glomerular filtration rate (eGFR) greater than 60 ml/min per 1.73 m were included. Urinary albumin excretion was measured in morning urine using a nephelometric immunoassay and expressed as albumin/creatinine ratio. Urinary pellets were obtained from fresh urine and mRNA was assessed by real-time quantitative PCR. Likewise, protein podocyte-specific molecules were measured by western blot using specific antibodies., Results: Fourteen nondiabetics and 20 diabetics had increased UAE greater than 30 mg/g. In individuals with increased EUA, the mRNA expression of nephrin and CD2AP was low in diabetics, whereas only nephrin mRNA in nondiabetics. No differences were observed in podocalyxin and aquaporin-1 mRNA levels. Concerning the protein values, in both nondiabetic and diabetic patients, nephrin, CD2AP and podocalyxin were increased in patients with increased UAE, with no differences in aquaporin-1. A significant positive relationship was observed between log UAE and nephrin protein values, and an inverse association observed with mRNA., Conclusion: Hypertensive patients who had elevated UAE showed increased urinary excretion of podocyte-specific proteins coupled with a phenotype of decreased mRNA expression. The phenotype of podocyte-specific mRNA and the increment of nephrin can be used as a valuable marker of early glomerular injury.

Objective: To assess the association of single-nucleotide polymorphisms (SNPs) in genes codifying for antioxidant enzymes to blood pressure (BP) values and risk of hypertension., Methods: Population-based study including 1388 participants (704 women) older than 18 years in which 300 were untreated hypertensive patients. In 335 untreated hypertensive patients referred to one hypertension clinic, the study was replicated. Thirty-five SNP throughout 13 genes were analyzed using SNPlex. In a subgroup of hypertensive patients, the amount of 8-oxo-deoxyguanosine and GPX activity levels was measured in mononuclear cells., Results: In the general population, genotypes with the G allele of the c.172G>A polymorphism in the SOD3 gene and those with the T allele of the c.-20C>T polymorphism in the CAT gene were associated with significant lower values of BP. Likewise, these genotypes were associated with less risk for hypertension after adjusting for confounder variables. Haplotypes in both genes increased the strength of associations. In the hypertensive patients, the same alleles of the two polymorphisms were associated with lower BP values too. In addition, two others, the CT-TT genotypes of the c.891C>T polymorphism in the GPX1 gene and the CT-CC genotypes of the c.-793T>C polymorphism of the TXN gene were also significantly associated to lower BP values. Furthermore, the CC genotype of the c.891C>T polymorphism in the GPX1 gene was associated with higher values of 8-oxo-dG and GPX activity levels as compared to those for the CT-TT genotype., Conclusions: The results of the present study support the influence of antioxidant enzyme genes in BP values and hypertension risk.

Background: To assess the association of polymorphisms and haplotypes of the mineralocorticoid receptor (MR) (NR3C2) gene to the risk of essential hypertension (HTN) in a Spanish population., Methods: This is a population-based study which included 1,502 subjects (748 women) >18 years old. Twenty-four polymorphisms of NR3C2 gene were analyzed by using SNPlex (Genotyping System based on OLA/PCR technology)., Results: Alleles of the single-nucleotide polymorphism (SNP) rs5522 were significantly associated with the risk of HTN, both in the recessive and codominant models adjusted by age, gender, and body mass index (BMI). Genotype GG of the rs5522 showed to be protective against HTN odds ratio (OR) 0.10 (0.02-0.56), P < 0.01. One haplotype, which included the G allele of the rs5522, was also associated with reduced risk of HTN and four haplotypes which included the A allele were associated with increased risk of HTN. When the 24-h urinary sodium excretion and the estimated glomerular filtration rate (eGFR) were added, they did not reduce the significance level. Interaction between genotypes of the rs5522 and quartiles of 24-h sodium excretion has been observed. In subjects with the AA genotype, those with higher urinary sodium excretion had the lowest risk to be hypertensive., Conclusion: A functional polymorphism of the NR3C2 gene was associated with risk of HTN. The data provided in this study seems to give credit to the hypothesis of the participation of MR gene in the development of HTN, although further studies are necessary to better assess its real impact.

Objective: Oxidative stress is implicated in hypertension and the NADPH oxidase systems constitute the main source of superoxide in vascular wall. We searched for new polymorphisms within the CYBA promoter, the human gene that encodes the p22phox protein, and studied their potential association with essential hypertension., Design: A case-control study in a random sample of the general population., Methods: CYBA polymorphisms were determined by restriction fragment length polymorphism and allelic discrimination. NADPH oxidase activity was quantified in phagocytic cells by chemiluminescence., Results: We identified three novel polymorphisms, at positions -852, -675 and -536 from the ATG codon. Only the -675(A/T) polymorphism associated with essential hypertension. The prevalence of the TT genotype and the T allele frequency were significantly higher (P < 0.05) in hypertensives than in normotensives. Furthermore, TT hypertensives exhibited higher (P < 0.05) systolic blood pressure values than TA/AA hypertensives. Increased phagocytic NADPH oxidase activity was observed in TT subjects compared to TA and AA individuals (P < 0.05). Enhanced carotid intima-media thickness, a surrogate marker of atherosclerosis, was found in TT subjects compared to TA and AA individuals (P < 0.05). Finally, mutagenesis experiments demonstrated a functional role of this polymorphism on the CYBA promoter activity., Conclusion: The -675 (A/T) CYBA polymorphism may be a novel genetic marker associated with essential hypertension. Furthermore, TT subjects exhibit features of NADPH oxidase-mediated oxidative stress and asymptomatic atherosclerosis.

Unlabelled: The potential use of oxidative stress products as disease markers and progression is an important aspect of biomedical research. In the present study, the quantification of urine 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) concentration has been used to express the oxidation status of hypertensive subjects. 8-oxo-dG has been simultaneously isolated and assayed in nuclear (nDNA) and mitochondrial DNA (mtDNA). In addition, oxidative stress of mononuclear cells has been estimated by means of GSH and GSSG levels and GSSG/GSH ratio in hypertensive subjects before and after antihypertensive treatment. It is shown that oxidative stress decreases significantly in hypertensive patients after treatment the effect being accompanied by reduction of their blood pressure. A significant correlation is observed comparing the yield of urine 8-oxo-dG and that isolated from mitochondria DNA. Moreover, urinary excretion of 8-oxo-dG also correlates with the GSSG/GSH ratio of cells., Conclusion: urine 8-oxo-dG assay is a good marker for monitoring oxidative stress changes in hypertensives.

Hypertension is frequently associated with oxidative stress caused by high production of reactive oxygen species and compromised antioxidant defenses. Humans with essential hypertension, with or without treatment, and controls were examined (35 hypertensive and 30 normotensive). We noted a discordant response of the glutathione and thioredoxin systems in essential hypertension and to antihypertensive treatment. Further studies examining the significance of these thiols in hypertension outcomes are warranted.

Untreated hypertensive patients show increased oxidative stress and decreased antioxidant enzyme activity in mononuclear cells. Therefore, the objective of this study was to determine whether or not the low antioxidant enzyme activity observed in mononuclear cells of hypertensive subjects is in part dependent on a defective activity of antioxidant mechanisms. Activity and mRNA level of antioxidant enzymes, CuZn- and Mn-superoxide dismutases, catalase, glutathione peroxidase type 1, and glutathione reductase were simultaneously measured in mononuclear cells of controls (n = 38) and hypertensive subjects (n = 35), in the absence of and during antihypertensive treatment. An increase in oxidative stress and a decrease in the activity of cytoplasmic enzymes were observed in untreated hypertensive patients. Concurrently, CuZn-superoxide dismutase and glutathione reductase mRNA levels were significantly reduced, and glutathione peroxidase type 1 mRNA was slightly reduced. In contrast, increased activity and mRNA levels of the mitochondrial Mn-superoxide dismutase were observed. Antihypertensive treatment, nonpharmacologic with or without a drug regimen of beta-blocker or angiotensin AT1 receptor blocker was administered for a 3-month period. Afterward, after the improvement in oxidative stress during treatment, a recovery of the cytoplasmic antioxidant enzymatic activity and a more profound decrease in mRNA levels were observed for CuZn-superoxide dismutase, glutathione peroxidase type 1, and glutathione reductase. Meanwhile mitochondrial enzymatic activity decreased, as did the mRNA level. The inadequate response of the main cytoplasmatic antioxidant systems, as well as of the enzymes participating in the maintenance of glutathione levels, may contribute to the vulnerability of hypertensives to oxidative stress.

Background: The renin-angiotensin system (RAS) is known to regulate the blood pressure (BP). Several RAS polymorphisms have been associated with essential hypertension (EH), but there is uncertainty about this association. We examined whether the insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene, and the M235T polymorphism of the angiotensinogen (AGT) gene were associated with EH in a sample of Spanish hipertensive patients., Patients and Method: We studied 1,204 patients with EH (BP > 140/90 mmHg): 668 males, aged 50.8 (13.6) years with systolic BP 151.7 (19.1) and diastolic BP 94.3 (13) mmHg [mean (SD)] and 536 females, aged 52.4 (13.9) years with systolic BP 155.1 (19.8) and diastolic BP 94.5 (12.3) mmHg. As a control group, 367 men and 280 women with no family history of cardiovascular disease who had a normal blood pressure were included. Polymorphisms were determined by PCR amplification of genomic DNA, followed by enzyme digestion for the AGT gene polymorphism., Results: The genotype distribution and allele frequencies of the two RAS polymorphisms were similar in hypertensive and control subjects. Similarly, there were no differences in BP level with regard to the genotype in male or female patients. In addition, we did not find any compound effect of the I/D ACE gene and M235T AGT gene polymorphisms on BP levels in hypertensive subjects., Conclusions: This study suggests that in the population studied, the contribution of the ACE I/D polymorphism and the AGT M235T polymorphism in the development of EH is less important than previously estimated.

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it. [ABSTRACT FROM AUTHOR]

Oxidative stress can modulate blood pressure levels in different models. Xanthine oxidoreductase is one of the enzymes producing free radicals in the cardiovascular system, and it can contribute to the increment of the oxidative stress and, consequently, blood pressure. We analyzed the association between the -337GA and 565+64CT polymorphisms of the xanthine oxidoreductase gene with blood pressure and oxidative stress levels.These polymorphisms were studied in a case-control study (185 patients with hypertension and 385 normotensive controls), we found that these polymorphisms were related to blood pressure levels. This association was high in patients with hypertension and showed an additive effect but did not increase the risk of developing hypertension. We studied an additional and independent sample of patients with hypertension (n=100) to know the association of these polymorphisms with oxidative stress levels.We found that these polymorphisms were related to blood pressure levels. This association was high in hypertensive patients and showed an additive effect, but does not increase the risk of developing hypertension. We have found that the same alleles related with higher blood pressure-337A and 565+64C were related with increased oxidative stress in patients with hypertension.Our results suggest that polymorphisms -337GA and 565+64CT of xanthine oxidoreductase gene are related with blood pressure and oxidative stress in hypertension, adding evidence to the role of xanthine oxidoreductase and oxidative stress in blood pressure. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it. [ABSTRACT FROM AUTHOR]