The natriuretic peptide system includes three known peptides: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). They contribute to the regulation of cardiovascular homeostasis through diuretic, natriuretic, and vasodilatory properties. Among them, ANP has received particular attention because of its effects on blood pressure regulation and cardiac function. Although the potential for its therapeutic application in the treatment of hypertension and heart failure has been evaluated in several experimental and clinical investigations, no pharmacological approach directly targeted at modulation of ANP levels has ever reached the stage of being incorporated into clinical practice. Recently, ANP has also received attention as being a possible cardiovascular risk factor, particularly in the context of hypertension, stroke, obesity, and metabolic syndrome. Abnormalities in either peptide levels or peptide structure are thought to underlie its implied role in mediating cardiovascular diseases. Meanwhile, BNP has emerged as a relevant marker of left ventricular (LV) dysfunction and as a useful predictor of future outcome in patients with heart failure. This review deals with the major relevant findings related to the cardiovascular and metabolic effects of natriuretic peptides, to their potential therapeutic use, and to their role in mediating cardiovascular diseases.

Our findings show that the ANP/NPRA system significantly contributes to ventricular remodeling in human essential hypertension.

Background and Purpose-A precise definition of genetic factors responsible for common forms of stroke is still lacking.The purpose of the present study was to investigate the contributory role of the genes encoding atrial natriuretic peptide (ANP) and type A natriuretic peptide receptor (NPRA) in humans' susceptibility to develop ischemic stroke. Methods-Allele and genotype frequencies of ANP and NPRA were characterized in an Italian case-control study with patients affected by vascular disease or risk factors. Subjects were recruited from the island of Sardinia (206 cases, 236 controls). Results-A significant association between the ANP/TC2238 polymorphic site and stroke occurrence was found when a recessive model of inheritance was assumed. The risk conferred by this mutant genotype, when estimated by multivariate logistic regression analysis, was 3.8 (95% confidence interval, 1.4 to 10.9). A significantly increased risk of stroke recurrence was observed among cases carrying the ANP/CC2238 genotype compared with cases carrying the ANP/TT2238 genotype (Pϭ0.04). No direct association of NPRA with stroke occurrence was detected. However, a significant epistatic interaction between the ANP/CC2238 genotype and an allelic variant of NPRA led to a 5.5-fold increased risk of stroke (95% confidence interval, 1.5 to 19.4). Conclusions-Our findings support a direct contributory role of ANP to stroke in humans. A significant interaction between ANP and NPRA on stroke occurrence was found.

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A trial natriuretic peptide (ANP), a cardiovascular hormone with natriuretic, diuretic, and vasodilator activity, 1 contributes to the risk of cardiovascular events depending on either abnormal circulating concentrations or peptide structural alterations.2 In the latter regard, the molecular variant of the prepro-ANP gene characterized by the substitution of thymidine with cytosine in position 2238 affects the incidence of cardiovascular events in different human populations.

BackgroundThe genetic basis of stroke susceptibility remains to be elucidated. STR1 quantitative trait locus (STR1/QTL) was identified on rat chromosome 1 of stroke‐prone spontaneously hypertensive rat (SHRSP) upon Japanese‐style stroke‐permissive diet (JD), and it contributes to 20% of the stroke phenotype variance.Methods and ResultsNine hundred eighty‐six probe sets mapping on STR1 were selected from the Rat RAE230A array and screened through a microarray differential expression analysis in brains of SHRSP and stroke‐resistant SHR (SHRSR) fed with either regular diet or JD. The gene encoding Ndufc2 (NADH dehydrogenase [ubiquinone] 1 subunit), mapping 8 Mb apart from STR1/QTL Lod score peak, was found significantly down‐regulated under JD in SHRSP compared to SHRSR. Ndufc2 disruption altered complex I assembly and activity, reduced mitochondrial membrane potential and ATP levels, and increased reactive oxygen species production and inflammation both in vitro and in vivo. SHRSR carrying heterozygous Ndufc2 deletion showed renal abnormalities and stroke occurrence under JD, similarly to SHRSP. In humans, T allele variant at NDUFC2/rs11237379 was associated with significant reduction in gene expression and with increased occurrence of early‐onset ischemic stroke by recessive mode of transmission (odds ratio [OR], 1.39; CI, 1.07–1.80; P=0.012). Subjects carrying TT/rs11237379 and A allele variant at NDUFC2/rs641836 had further increased risk of stroke (OR=1.56; CI, 1.14–2.13; P=0.006).ConclusionsA significant reduction of Ndufc2 expression causes complex I dysfunction and contributes to stroke susceptibility in SHRSP. Moreover, our current evidence may suggest that Ndufc2 can contribute to an increased occurrence of early‐onset ischemic stroke in humans.

534R enal vascular and parenchymal lesions represent a common target organ damage in hypertension.1,2 Clinical studies show that blood pressure (BP) lowering reduces renal damage and progression to renal failure. 3 Previous studies focused on the role of high-BP levels, abnormalities of the renin-angiotensin system, and excess of dietary salt intake as important factors contributing to pathogenesis of renal lesions associated to hypertension in both animal models and humans. 4 In the stroke-prone spontaneously hypertensive rat (SHRsp), renal vascular and tissue lesions develop after only 4 weeks of high-salt/low-potassium (HS) Japanese-style diet. In contrast, in spite of similar BP levels at 4 weeks, the parental strain strictly related to SHRsp (stroke-resistant SHR [SHRsr]) displays a much lesser degree of renal damage. 5 In the SHRsp, renal lesions precede the development of cerebrovascular lesions suggesting common underlying etiopathogenetic mechanisms. 6HS diet enhances vascular oxidant stress leading to vascular dysfunction.7 Of note, the mitochondrion has emerged as a major source of reactive oxygen species (ROS) in the vasculature. 8 Within the mitochondria, uncoupling protein 2 (UCP2) has recently been reported as a negative regulator of ROS generation.9 Its ablation leads to marked increase of oxidative stress in several cell types.10 Moreover, lack of UCP2 exacerbates HS-induced vascular dysfunction in salt-loaded mice. 11 UCP2 genetic variants have been associated to predisposition to renal damage development in humans. 12,13 In the present study, we investigated whether a dysfunctional UCP2 is associated with increased renal vascular damage in SHRsp. Based on the identification of lower UCP2 expression only in the kidneys of SHRsp under HS diet, we explored the in vitro functional impact of UCP2 downregulation on ROS production, inflammation, apoptosis, and necrosis in rat renal mesangial cells. Finally, we attempted to identify Abstract-The stroke-prone spontaneously hypertensive rat (SHRsp) represents an animal model of increased susceptibility to high-salt diet-induced cerebral and renal vascular injuries. High blood pressure and genetic factors are viewed as major contributing factors. In high-salt-loaded SHRsp and stroke-resistant SHR animals, we determined blood pressure levels, degree of kidney lesions, renal uncoupling protein 2 (UCP2) gene and protein expression levels along with rattus norvegicus (rno)-microRNA (miR) 24 and 34a gene expression, nuclear factor-κB protein levels, and oxidative stress. In vitro, UCP2 gene silencing was performed in renal mesangial cells. We found more severe degree of renal damage in SHRsp at the end of 4-week high-salt dietary treatment as compared with stroke-resistant SHR, despite comparable blood pressure levels, along with increased rate of inflammation and oxidative stress. Kidney UCP2 gene and protein expression levels were significantly downregulated under high-salt diet in SHRsp, but not in stroke-resistant SHR. Differential UCP2 regulation was par...

Uncoupling protein 2 (UCP2) is an inner mitochondrial membrane protein that belongs to the uncoupling protein family and plays an important role in lowering mitochondrial membrane potential and dissipating metabolic energy with prevention of oxidative stress accumulation. In the present article, we will review the evidence that UCP2, as a consequence of its roles within the mitochondria, represents a critical player in the predisposition to vascular disease development in both animal models and in humans, particularly in relation to obesity, diabetes, and hypertension. The deletion of the UCP2 gene contributes to atherosclerosis lesion development in the knockout mice, also showing significantly shorter lifespan. The UCP2 gene downregulation is a key determinant of higher predisposition to renal and cerebrovascular damage in an animal model of spontaneous hypertension and stroke. In contrast, UCP2 overexpression improves both hyperglycemia- and high-salt diet-induced endothelial dysfunction and ameliorates hypertensive target organ damage in SHRSP. Moreover, drugs (fenofibrate and sitagliptin) and several vegetable compounds (extracts from Brassicaceae, berberine, curcumin, and capsaicin) are able to induce UCP2 expression level and to exert beneficial effects on the occurrence of vascular damage. As a consequence, UCP2 becomes an interesting therapeutic target for the treatment of common human vascular diseases.