Nitric Oxide Deficiency Research Articles

Statins in Chronic Kidney Disease-Effects on Atherosclerosis and Cellular Senescence.

Chronic kidney disease (CKD) is a serious health problem that can affect various systems in the human body. Renal failure promotes mechanisms of premature cellular aging and also features of generalized inflammation in the body, which translates into a close relationship between kidney dysfunction and cardiovascular disease (CVD). As kidney function deteriorates, cardiovascular risk and mortality increase in this group of patients. Oxidative stress and inflammation are two closely related processes that initiate a vicious cycle by activating each other. Together with aging, they represent the key factors that cause and exacerbate CVD in CKD. Patients with CKD are particularly vulnerable to the accumulation of aging endothelial cells, vascular smooth muscle and macrophages, increasing the risk of atherosclerosis. Several mechanisms are known that can lead to the progression of the aforementioned problems, such as the accumulation of uremic toxins, persistent inflammation, impaired lipid and electrolyte metabolism, nitric oxide (NO) deficiency, the increased production of reactive oxygen species (ROS) and damage to deoxyribonucleic acid (DNA) and mitochondria. According to research, we can distinguish a group of drugs that effectively counteract the negative effects of CKD-statins. This is a group of drugs that inhibit 3-hydroxy-3-methylglutaryl-coenzyme-A (HMG-CoA) reductase and affect a number of cellular processes and pathways, resulting in the overall slowing of atherosclerosis and cellular aging.

Inflammatory Mediators of Endothelial Dysfunction.

Endothelial dysfunction (ED) is characterized by imbalanced vasodilation and vasoconstriction, elevated reactive oxygen species (ROS), and inflammatory factors, as well as deficiency of nitric oxide (NO) bioavailability. It has been reported that the maintenance of endothelial cell integrity serves a significant role in human health and disease due to the involvement of the endothelium in several processes, such as regulation of vascular tone, regulation of hemostasis and thrombosis, cell adhesion, smooth muscle cell proliferation, and vascular inflammation. Inflammatory modulators/biomarkers, such as IL-1α, IL-1β, IL-6, IL-12, IL-15, IL-18, and tumor necrosis factor α, or alternative anti-inflammatory cytokine IL-10, and adhesion molecules (ICAM-1, VCAM-1), involved in atherosclerosis progression have been shown to predict cardiovascular diseases. Furthermore, several signaling pathways, such as NLRP3 inflammasome, that are associated with the inflammatory response and the disrupted H2S bioavailability are postulated to be new indicators for endothelial cell inflammation and its associated endothelial dysfunction. In this review, we summarize the knowledge of a plethora of reviews, research articles, and clinical trials concerning the key inflammatory modulators and signaling pathways in atherosclerosis due to endothelial dysfunction.

Protective effects of long-term nitrate administration against ovariectomy-induced kidney dysfunction in rats.

Menopause is associated with higher risks of chronic kidney disease. We determined the effect of nitrate on ovariectomy-induced kidney dysfunction METHODS: Control, ovariectomized (OVX), control + nitrate, and OVX + nitrate female Wistar rats (n = 10/group); sodium nitrate (100mg/L) administered in drinking water for 9months. Glomerular filtration rate (GFR) and albumin excretion rate (AER) were calculated from serum and urine parameters. At month 9, serum and kidney levels of nitric oxide (NO) metabolites (NOx), oxidative stress indices, and mRNA expression of endothelial NO synthase (eNOS) were measured; with histological analyses of the kidney. Compared to controls, OVX rats had lower GFR (31%, p = 0.0079), higher glomerular tuft volume (30%, p = 0.0402), and Bowman's capsule space (39%, p = 0.0224). OVX rats had lower serum NOx (33%, p = 0.0061) and kidney eNOS mRNA expression (34%, p = 0.0368). Nitrate administration to: (i) control rats increased serum NOx (59%, p < 0.0001), with no effect on other parameters; (ii) OVX rats increased serum (85%, p < 0.0001) and kidney (106%, p = 0.0008) NOx values, and restored kidney eNOS expression to normal value. Nitrate administration to OVX rats increased GFR (36%, p = 0.0361) and restored glomerular tuft volume and Bowman's capsule space to normal values. In OVX rats, it also increased serum catalase (CAT) activity, serum and kidney total antioxidant capacity (TAC), and decreased serum malondialdehyde (MDA). Low-dose long-term nitrate administration protects against ovariectomy-induced kidney dysfunction in rats. This effect is associated with reducing ovariectomy-induced oxidative stress and restoring eNOS-derived NO deficiency in systemic circulation and the kidney.

Sulfur-Containing Amino Acids, Hydrogen Sulfide, and Sulfur Compounds on Kidney Health and Disease

Hydrogen sulfide (H2S) plays a decisive role in kidney health and disease. H2S can ben synthesized via enzymatic and non-enzymatic pathways, as well as gut microbial origins. Kidney disease can originate in early life induced by various maternal insults throughout the process, namely renal programming. Sulfur-containing amino acids and sulfate are essential in normal pregnancy and fetal development. Dysregulated H2S signaling behind renal programming is linked to deficient nitric oxide, oxidative stress, the aberrant renin–angiotensin–aldosterone system, and gut microbiota dysbiosis. In animal models of renal programming, treatment with sulfur-containing amino acids, N-acetylcysteine, H2S donors, and organosulfur compounds during gestation and lactation could improve offspring’s renal outcomes. In this review, we summarize current knowledge regarding sulfide/sulfate implicated in pregnancy and kidney development, current evidence supporting the interactions between H2S signaling and underlying mechanisms of renal programming, and recent advances in the beneficial actions of sulfide-related interventions on the prevention of kidney disease. Modifying H2S signaling is the novel therapeutic and preventive approach to reduce the global burden of kidney disease; however, more work is required to translate this into clinical practice.

Adiponectin receptor activation with AdipoRon prevents Truvada-induced microvascular oxidative stress and dysfunction in mice

Background: Persons living with the human immunodeficiency virus (PLHIV) and treated with anti-retroviral therapy such as emtricitabine and tenofovir disoproxil fumarate (Truvada, TVD) have increased cardiovascular risk but the mehcamisms and management are unclear. Since we found that PLHIV treated with antiretroviral drugs including TVD had significantly (P&lt;0.05) decreased adiponectin in plasma (3.3±0.3 vs 4.5±0.5 μg · mL-1) and in perivascular adipose tissue (14±1 vs 22±2 μg·mg protein-1 ·mL-1), we tested the hypothesis that impaired adiponectin signaling with TVD causes microvascular dysfunction. Methods: CB57Bl/6 mice (n=6-8/ group) were administered vehicle (Veh), TVD (30 mg/kg/day), AdipoRon (ADR; adiponectin receptor agonist; 50 ug/kg/day) or both orally for 28 days. Mesenteric resistance arterioles were studied on isometric myographs and microvascular nitric oxide (NO) and reactive oxygen species (ROS) by RatioMaster. Results: TVD significantly (P&lt;0.05) increased malondialdehyde in serum (50±5 vs 17±2 μM) and in urine (59±15 vs 7±3 μM), urine albumin/creatinine ratio (0.9±0.1 vs 0.04±0.0), microvascular contractions to U-46,619 (98± vs 88±3%; P&lt;0.05) and endothelin-1 (83± vs 69±3%), cellular ROS (DHE: 0.29±0.03 vs 0.15±0.04 unit) and mitochondrial ROS (mitotempo: 0.25±0.04 vs 0.12±0.03 unit) and reduced endothelium-dependent relaxation (48± vs 81±3%) and NO (0.28±0.03 vs 0.42±0.07 units). ADR alone did not alter these measurements but significantly (P&lt;0.05) prevented all of these effects of TVD. Conclusions: Activation of adiponectin receptors prevents the systemic and microvascular oxidative stress, microvascular endothelial dysfunction and NO deficiency and enhanced contractility caused by one month of TVD. Therefore, AdipoRon may mitigate the excess cardiovascular disease of PLHIV who are receiving Truvada. NIH National Heart, Lung, and Blood Institute, NIH 5RO1-HL134511 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Natural history of epilepsy in argininosuccinic aciduria provides new insights into pathophysiology: A retrospective international study.

Argininosuccinate lyase (ASL) is integral to the urea cycle, which enables nitrogen wasting and biosynthesis of arginine, a precursor of nitric oxide. Inherited ASL deficiency causes argininosuccinic aciduria, the second most common urea cycle defect and an inherited model of systemic nitric oxide deficiency. Patients present with developmental delay, epilepsy, and movement disorder. Here we aim to characterize epilepsy, a common and neurodebilitating comorbidity in argininosuccinic aciduria. We conducted a retrospective study in seven tertiary metabolic centers in the UK, Italy, and Canada from 2020 to 2022, to assess the phenotype of epilepsy in argininosuccinic aciduria and correlate it with clinical, biochemical, radiological, and electroencephalographic data. Thirty-seven patients, 1-31 years of age, were included. Twenty-two patients (60%) presented with epilepsy. The median age at epilepsy onset was 24 months. Generalized tonic-clonic and focal seizures were most common in early-onset patients, whereas atypical absences were predominant in late-onset patients. Seventeen patients (77%) required antiseizure medications and six (27%) had pharmacoresistant epilepsy. Patients with epilepsy presented with a severe neurodebilitating disease with higher rates of speech delay (p = .04) and autism spectrum disorders (p = .01) and more frequent arginine supplementation (p = .01) compared to patients without epilepsy. Neonatal seizures were not associated with a higher risk of developing epilepsy. Biomarkers of ureagenesis did not differ between epileptic and non-epileptic patients. Epilepsy onset in early infancy (p = .05) and electroencephalographic background asymmetry (p = .0007) were significant predictors of partially controlled or refractory epilepsy. Epilepsy in argininosuccinic aciduria is frequent, polymorphic, and associated with more frequent neurodevelopmental comorbidities. We identified prognostic factors for pharmacoresistance in epilepsy. This study does not support defective ureagenesis as prominent in the pathophysiology of epilepsy but suggests a role of central dopamine deficiency. A role of arginine in epileptogenesis was not supported and warrants further studies to assess the potential arginine neurotoxicity in argininosuccinic aciduria.

The Nitric Oxide (NO) Donor Molsidomine Counteract Social Withdrawal and Cognition Deficits Induced by Blockade of the NMDA Receptor in the Rat

The deficiency of the gaseous molecule nitric oxide (NO) seems to be critically involved in the pathogenesis of schizophrenia. Thus, molecules that can normalize NO levels, as are NO donors, might be of utility for the medication of this psychiatric disease. The aim of the present study was to detect the ability of the NO donor molsidomine to reduce schizophrenia-like impairments produced by the blockade of the N-methyl-D-aspartate (NMDA) receptor in rats. Molsidomine's ability to attenuate social withdrawal and spatial recognition memory deficits induced by the NMDA receptor antagonist ketamine were assessed using the social interaction and the object location test, respectively. Further, the efficacy of the combination of sub-effective doses of molsidomine with sub-effective doses of the atypical antipsychotic clozapine in alleviating non-spatial recognition memory deficits was evaluated utilizing the object recognition task. Molsidomine (2 and 4 mg/kg) attenuated social withdrawal and spatial recognition memory deficits induced by ketamine. Co-administration of inactive doses of molsidomine (1 mg/kg) and clozapine (0.1 mg/kg) counteracted delay-dependent and ketamine-induced non-spatial recognition memory deficits. The current findings suggest that molsidomine is sensitive to glutamate hypofunction since it attenuated behavioral impairments in animal models mimicking the negative symptoms and cognitive deficits of schizophrenia. Additionally, the present results support the potential of molsidomine as an adjunctive drug for the therapy of schizophrenia.

Overview and New Insights into the Metabolic Syndrome: Risk Factors and Emerging Variables in the Development of Type 2 Diabetes and Cerebrocardiovascular Disease.

Metabolic syndrome (MetS) is considered a metabolic disorder that has been steadily increasing globally and seems to parallel the increasing prevalence of obesity. It consists of a cluster of risk factors which traditionally includes obesity and hyperlipidemia, hyperinsulinemia, hypertension, and hyperglycemia. These four core risk factors are associated with insulin resistance (IR) and, importantly, the MetS is known to increase the risk for developing cerebrocardiovascular disease and type 2 diabetes mellitus. The MetS had its early origins in IR and syndrome X. It has undergone numerous name changes, with additional risk factors and variables being added over the years; however, it has remained as the MetS worldwide for the past three decades. This overview continues to add novel insights to the MetS and suggests that leptin resistance with hyperleptinemia, aberrant mitochondrial stress and reactive oxygen species (ROS), impaired folate-mediated one-carbon metabolism with hyperhomocysteinemia, vascular stiffening, microalbuminuria, and visceral adipose tissues extracellular vesicle exosomes be added to the list of associated variables. Notably, the role of a dysfunctional and activated endothelium and deficient nitric oxide bioavailability along with a dysfunctional and attenuated endothelial glycocalyx, vascular inflammation, systemic metainflammation, and the important role of ROS and reactive species interactome are discussed. With new insights and knowledge regarding the MetS comes the possibility of new findings through further research.

Altered sialin mRNA gene expression in type 2 diabetic male Wistar rats: implications for nitric oxide deficiency

Nitrate therapy has been suggested to boost nitric oxide (NO) levels in type 2 diabetes (T2D); however, little is known about nitrate transport across the membranes. This study aimed to assess changes in the mRNA expression of sialin, as a nitrate transporter, in the main tissues of rats with T2D. Rats were divided into two groups (n = 6/group): Control and T2D. A high-fat diet combined with a low dose of streptozotocin (STZ, 30 mg/kg) was used to induce T2D. At month 6, samples from the main tissues of rats were used to measure the mRNA expression of sialin and levels of NO metabolites. Rats with T2D had lower nitrate levels in the soleus muscle (66%), lung (48%), kidney (43%), aorta (30%), adrenal gland (58%), epididymal adipose tissue (eAT) (61%), and heart (37%) and had lower nitrite levels in the pancreas (47%), kidney (42%), aorta (33%), liver (28%), eAT (34%), and heart (32%). The order of sialin gene expression in control rats was: soleus muscle > kidney > pancreas > lung > liver > adrenal gland > brain > eAT > intestine > stomach > aorta > heart. Compared to controls, rats with T2D had higher sialin mRNA expressions in the stomach (2.1), eAT (2.0), adrenal gland (1.7), liver (8.9), and soleus muscle (3.4), and lower sialin expression in the intestine (0.56), pancreas (0.42), and kidney (0.44), all P values < 0.05. These findings indicate altered sialin mRNA expression in the main tissues of male T2D rats and may have implications for future NO-based treatment of T2D.

Новое в лечении сердечной недостаточности: верицигуат

The author reviews the pharmacological properties and clinical trials of vericiguate, a stimulant of soluble guanylate cyclase, that is intended for use in patients with chronic heart failure. The new medicine alleviates unfavorable effects of endothelial dysfunction and other disorders associated with a deficiency of bioavailable nitric oxide and suppressed activity of soluble guanylate cyclase. The efficacy of vericiguate in chronic heart failure with a reduced ejection fraction was established in clinical trials SOCRATES-REDUCED and VICTORIA.

Anti-Hypertensive Property of an NO Nanoparticle in an Adenine-Induced Chronic Kidney Disease Young Rat Model.

Hypertension is the most common complication of chronic kidney disease (CKD) in children but is still poorly controlled. Nitric oxide (NO) deficiency plays a pivotal role in CKD and hypertension. NO is known to have health benefits, while NO typically has a short half-life and is not specifically targeted. In this study, we used a pediatric CKD model, which was induced in young rats by feeding them 0.25% adenine. We investigated two different NO donors, namely S-nitrosoglutathione (GSNO) and diethylenetriamine/NO adduct (DETA NONOate) via intraperitoneal injection at 10 mg/kg/day daily for 3 weeks. GSNO was delivered by Cu2+-doped zeolitic imidazolate framework (Cu/ZIF-8) nanoparticles to generate NO. As a result, we observed Cu/ZIF-8 nanoparticles were successfully loaded with GSNO and were able to release NO. Young rats fed with adenine displayed kidney dysfunction and hypertension at 9 weeks of age, which were prevented by GSNO-loaded nanoparticle or DETA NONOate treatment. GSNO-loaded nanoparticles reduced CKD-induced hypertension, which was related to an enhanced endogenous NO-generating system, reduced renal oxidative stress, and downregulated several components belonging to the classic renin-angiotensin (RAS) system. Our results cast new light on targeting NO delivery through the use of nanoparticles aiming to improve child-focused outcomes related to CKD worthy of clinical translation.

Endothelioprotective property of the combination of the thioctic acid and rosuvastatin shown in the endothelial dysfunction models

During the experiment, the modeling of endothelial dysfunction of male rats was performed by intraperitoneal administration of L-NAME at a dose of 25 mg/kg for 7 days, and the same of female rats was performed by bilateral ovarioectomy and further intraperitoneal administration of L-NAME at a dose of 25 mg/kg for 7. The deficiency of nitric oxide as a result of the NO-synthase blockade was accompanied by the impairment of the endotheliumdependent and independent vasodilatation estimated in the pharmacological tests, which was expressed in the increasing coefficient of endothelial dysfunction. As a result of the research it was discovered that the combined application of thioctic acid at a dose of 50 mg/kg/day with antioxidant features and rosuvastatin at a dose of 0.85 mg/kg/day, which is a lipid-lowering drug, has endothelioprotective effect on the models of L-NAME-induced and hypoestrogen-LNAME-induced deficiency of nitric oxide, which is expressed in prevalence of endotheliumdependent relaxations of vessels and decreasing coefficient of endothelial dysfunction, as well as prevention of increase in nitric oxide production.

EXPERIMENTAL PARTICIPATION OF PHARMACOLOGICAL SUBSTANCES IN MECHANISMS OF LEAD ACETATE TOXICITY

The aim of the work is to study pharmacological substances that play a role of eNOS expression regulators in the modification of lead intoxication effects in the experiment.Materials and methods. In the experiment, linear male rats of the same age were used: intact and with lead intoxication (120 heads). The study design was the following: group 1 – control; group 2 – intoxication with a lead acetate solution; group 3 – intact + L-nitroarginine methyl ester; group 4 – lead acetate + L-nitroarginine methyl ester; group 5 – intact + L-arginine; group 6 – lead acetate + L-arginine. The research carried out the study state of the redox reactions, the content of nitric oxide (NOx) stable metabolites, a lipid profile, the level of NO-synthase (eNOS) expression in the vascular endothelium, the main processes of urination and the activity of Na+/K+-ATPase in the renal tissue layers, as well as in the liver. The results were subjected to statistical processing.Results. Saturnism caused the oxidative stress development, a decrease in the NOx content in blood plasma, a violation of the L-arginine for eNOS bioavailability, and an endothelial dysfunction. Indicators of the impaired renal function were a decrease in the glomerular filtration rate (GFR), the tubular reabsorption of water, sodium, and the Na+/K+-ATPase activity. The damage to hepatocytes was evidenced by changes in the activity of organ-specific enzymes in the blood and Na+/K+-ATPase. L-arginine exhibited antioxidant properties, increased the NOx content and the level of eNOS expression. The eNOS L-nitroarginine methyl ester inhibitor showed the effects opposite to L-arginine.Conclusion. Biochemical markers of damage to kidney and liver cells during saturnism are indicators of the oxidative stress, NOx deficiency and hemodynamic disturbances in them. These mechanisms involved the following pharmacological substances: an eNOS inhibitor, L-nitroarginine methyl ester, which caused a decrease in the expression level of the enzyme, and an eNOS inducer, L-arginine, which increased this indicator severity. The lead toxicity mechanisms have been implicated in the impaired cholesterol metabolism, contributing to the L-arginine reduced availability for eNOS and the NOx production. Therefore, the use of L-arginine can be recommended as a regulator of the oxidative stress and an NO-producing endothelial function in other pathologies.

Nitric Oxide Precursors and Dimethylarginines as Risk Markers for Accelerated Measured GFR Decline in the General Population

Nitric oxide (NO) deficiency is associated with endothelial dysfunction, hypertension, atherosclerosis, and chronic kidney disease (CKD). Reduced NO bioavailability is hypothesized to play a vital role in kidney function impairment and CKD. We investigated the association of serum levels of endogenous inhibitors of NO, asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA), and precursors of NO, arginine, citrulline, and ornithine, with a decline in glomerular filtration rate (GFR) and new-onset CKD. In a prospective cohort study of 1407 healthy, middle-aged participants of Northern European origin in the Renal Iohexol Clearance Survey (RENIS), GFR was measured repeatedly with iohexol clearance during a median follow-up time of 11 years. GFR decline rates were analyzed using a linear mixed model, new-onset CKD (GFR< 60 ml/min per 1.73 m2) was analyzed with interval-censored Cox regression, and accelerated GFR decline (the 10% with the steepest GFR decline) was analyzed with logistic regression. Higher SDMA was associated with slower annual GFR decline. Higher levels of citrulline and ornithine were associated with accelerated GFR decline (odds ratio [OR], 1.43; 95% confidence interval [CI] 1.16-1.76 per SD higher citrulline and OR 1.23; 95% CI 1.01 to 1.49 per SD higher ornithine). Higher citrulline was associated with new-onset CKD, with a hazard ratio of 1.33 (95% CI 1.07-1.66) per SD higher citrulline. Associations between NO precursors and the outcomes suggest that NO metabolism plays a significant role in the pathogenesis of age-related GFR decline and the development of CKD in middle-aged people.

EFFECT OF MODULATION OF NITROGEN OXIDE (II) SYNTHESIS UNDER CHRONIC NORMOBARIC HYPOXIA ON THE ISOENZYME SPECTRUM OF RAT EPIDIDIMIS LACTATE DEHYDROGENASE

Lactate dehydrogenase have a key role in providing energy to cells under physiological and hypoxic conditions. Changes in the activity of the enzyme can be facilitated by nitric oxide (II), regulating the expression of individual fractions of lactate dehydrogenase. Aim. To study changes in the isoenzyme spectrum of rat epididymis lactate dehydrogenase under conditions of hypoxia and modulation of nitric oxide (II) synthesis. Material and methods. Male rats (32) were divided into 4 groups (n=8): 1) chronic normobaric hypoxia; 2) control to group 1; 3) hypoxia together with modeling of nitric oxide deficiency; 4) hypoxia against the background of induction of NO synthesis. The mitochondrial fraction and non-mitochondrial cytoplasm of the head and tail of the epididymis were isolated for laboratory research. The zymogram was obtained by electrophoresis in 7% gel followed by detection by the precipitation reaction of the reduction of nitro blue tetrazolium. The overall activity of lactate dehydrogenase was assessed and the percentage of isoenzyme fractions was calculated. Fractions 1 and X of lactate dehydrogenase were analyzed, the results were con-sidered statistically significant if p 0.05 when comparing two independent samples, and p 0.0167 when comparing three independent samples. Results. Chronic normobaric hypoxia leads to a decrease in lactate dehydrogenase activity compared to the control group. At the same time, the share of the X-fraction of the enzyme and lactate dehydrogenase 1 increases. Modulation of nitric oxide (II) deficiency against the background of hy-poxia increased the activity of the enzyme in the head of the epididymis, where a decrease in the studied fractions of lactate dehydrogenase was ob-served compared to the group of animals subjected only to hypoxia. Stimulation of the synthesis of nitric oxide (II) during hypoxia led to a decrease in the X-fraction, but an increase in the 1st fraction of lactate dehydrogenase in the head of the epididymis, in the tail of the epididymis, opposite changes were observed. Conclusion. Hypoxia causes a change in the ratio of lactate dehydrogenase isoenzymes towards an increase in lactate dehydrogenase B and lactate dehydrogenase X, while a deficiency of nitric oxide (II) contributes to a decrease in lactate dehydrogenase X synthesis.

Raynaud's Phenomenon: A Brush Up!

Raynaud's Phenomenon: A Brush Up!

PS-B09-2: ENOS-NO PATHWAY MODULATES AKI TO CKD TRANSITION IN IRI MODEL MICE VIA REGULATION OF B;CATENIN TRANSLOCATION

Background: The incidence of acute kidney injury (AKI) has increased over the past few decades. AKI is also currently recognized as an inducer of chronic kidney disease (CKD) through a process known as the AKI to CKD transition. It has been shown that aging and hypertension are risk factor for the AKI to CKD transition. Because these conditions are related to endothelial dysfunction, we hypothesized that the AKI to CKD transition is promoted by deficiency in the eNOS Nitric Oxide (NO) pathway as an endothelial dysfunction, and we used eNOS deficient mice (eNOSKO) and wild-type (WT) mice (C57B6/J: WT) to determine the mechanism of the AKI to CKD transition. Methods: WT and eNOSKO mice were used to determine the role of the eNOS NO pathway. Ischemic reperfusion was performed two weeks after uni-nephrectomization. The ischemic time was 20 min. The WT and eNOSKO mice were divided into four groups: WT sham, WT ischemic reperfusion injury (IRI), eNOSKO-sham and eNOSKO IRI. The first theses mice were sacrificed on Day 28 (D28) after the IRI (WT IRI D28 and eNOS IRI D28). Pathological analysis was conducted using Masson staining and KIM1 staining. Inflammation was assessed using quantitative PCR (qPCR) (IL1β;, IL6, and F4/80) and flow cytometry (FACS) analysis. Results: There was no evidence of kidney damage in the WT IRI D28 group. However, KIM1 staining detected tubular cell damage in the eNOSKO IRI D28 group. Fibrosis, which was assessed using the Masson staining, was also exacerbated in the eNOSKO IRI D28 group compared with the WT IRI D28 group. These results suggested that deficient eNOS NO signaling promoted the AKI to CKD transition. Next, the WT-IRI and eNOS IRI mice were sacrificed on Day 1 (D1) after the IRI (WT IRI D1 and eNOSKO IRI D1) to evaluate inflammation and kidney damage in the acute phase after IRI. There were no differences in kidney damage and inflammation between the WT-IRI-D1 and eNOSKO-IRI-D1 groups. In addition, at each time point (D7, Day 14 (D14), and D28) after IRI, qPCR was used to detect Wnt β;catenin related gene expression in the entire kidney. Expression of these genes was increased in the eNOSKO IRI D7 group compared with the WT IRI D7 group. Conclusions: Our results showed that after ischemic reperfusion, deficiency in the eNOS NO pathway promotes the AKI to CKD transition via acceleration of Wnt β;catenin. Therefore, activation of the eNOS NO pathway could be a potential therapeutic target in AKI.

PS-B05-12: ANTIHYPERTENSIVE AND CARDIO-PROTECTIVE POTENTIAL OF O. SANCTUM LEAVES EXTRACT IN L-NAME INDUCED HYPERTENSIVE RATS

Objective: There are approximately 26% of adults in the world who suffer from hypertension, which is the most common cardiovascular disease. Essential hypertension is mainly caused by endothelial dysfunction which results from nitric oxide (NO) deficiency. The present study sought to determine the impact of O. sanctum leaf extract (OS) in protecting against L-NAME induced hypertension and oxidative stress in wistar rats. Design and method: A non-specific nitric oxide inhibitor, L-NAME, (40 mg/kg/day), was administered to male Wistar rats to induce hypertension. CoQ10 was used as a standard anti-hypertensive compound. All of the other groups received L-NAME combined with OS extract (200 mg/kg/day) orally for three weeks. Following the treatment, hemodynamic parameters were measured using direct cannulation. The lipid profile, kidney and cardiac functions, as well as markers of oxidative stress were evaluated. The results were expressed as mean ± SD. Results: L-NAME was found to cause high blood pressure, NO depletion, oxidative imbalance and damage in cardiac and kidney function in animals. The Cardiac markers enzyme level were significantly increased in L-NAME only group whereas, the CO-treatment group had lower lower of Cardiac markers as compared to control as well as L-NAME group. In hypertensive rats, OS treatment significantly lowers the expression of angiotensin converting enzyme (ACE) and mineralocorticoid receptor expression in hypertensive rats. Concurrent treatment with L-NAME and OS extract prevented the all injuries without affecting the heart rate or raising blood pressure. Conclusions: The results confirm O. Sanctum leaves extract antihypertensive action and indicate its protective properties in the L-NAME induced hypertension model of rats, likely due to the presence of rich antioxidant potential and by inhibiting the inflammation.

H2O2 Mediates VEGF- and Flow-Induced Dilations of Coronary Arterioles in Early Type 1 Diabetes: Role of Vascular Arginase and PI3K-Linked eNOS Uncoupling

In diabetes, the enzyme arginase is upregulated, which may compete with endothelial nitric oxide (NO) synthase (eNOS) for their common substrate L-arginine and compromise NO-mediated vasodilation. However, this eNOS uncoupling can lead to superoxide production and possibly vasodilator hydrogen peroxide (H2O2) formation to compensate for NO deficiency. This hypothesis was tested in coronary arterioles isolated from pigs with 2-week diabetes after streptozocin injection. The NO-mediated vasodilation induced by flow and VEGF was abolished by NOS inhibitor L-NAME and phosphoinositide 3-kinase (PI3K) inhibitor wortmannin but was not affected by arginase inhibitor Nω-hydroxy-nor-L-arginine (nor-NOHA) or H2O2 scavenger catalase in control pigs. With diabetes, this vasodilation was partially blunted, and the remaining vasodilation was abolished by catalase and wortmannin. Administration of L-arginine or nor-NOHA restored flow-induced vasodilation in an L-NAME sensitive manner. Diabetes did not alter vascular superoxide dismutase 1, catalase, and glutathione peroxidase mRNA levels. This study demonstrates that endothelium-dependent NO-mediated coronary arteriolar dilation is partially compromised in early type 1 diabetes by reducing eNOS substrate L-arginine via arginase activation. It appears that upregulated arginase contributes to endothelial NO deficiency in early diabetes, but production of H2O2 during PI3K-linked eNOS uncoupling likely compensates for and masks this disturbance.

Vascular primary cilia in the pathogenesis of hypertension and Alzheimer's Disease

AbstractBackgroundPrimary cilia are microtubule‐based organelles, extending from the surface of cells to sense extracellular signaling cues. We demonstrated that the inability of endothelial cilia to sense and transmit fluid‐shear stress can lead to nitric oxide (NO) deficiency and cause vascular HTN. HTN can cause brain microvascular endothelial mechanical stress, damage the neurovascular unit, and ultimately induce cognitive impairment, contributing to the progression of AD. It is well documented that decreased biosynthesis of NO contributes to cerebral amyloid angiopathy in AD patients through increased deposition of Aβ. Disruption of the cholinergic neurotransmitter pathway, which is important for cognition, memory and learning abilities has been reported in AD patients. However, the connection between cilia and mAChR signaling in the brain has never been investigated. We propose a bold idea to look at the pathophysiological roles of cerebrovascular ciliary receptors in BP and AD.MethodImmunofluorescence of human brain endothelial cells (HBECs) were employed to study AChM3R localization and its downstream effectors. Cilia length and function (eNOS activation) studies were carried out to examine if mAChRs activation would enhance cilia structure and function. siRNA‐mediated knockdown of Tulp‐3 was performed to block AChM3R trafficking to primary cilia and study its activity. HBECs were exposed to synthetic Aβ to study their effect on cilia structure and ciliogenesis. Vascular‐specific cilia and AChM3R knockout mice were generated to study blood pressure and AD manifestations.ResultWe discovered that AChM3R, PIP2, and eNOS localize to primary cilia. mAChR‐specific activation (CDD‐0102A) increases cilia length in HBECs and cilia formation in cilialess Tg737 cells and was also associated with an increase in eNOS activity. Exposure to 2.5 μM human Aβ42 resulted in significant reduction in primary cilia length and ciliation percentage. RNAi‐mediated knockdown of Tulp3 caused a significant decrease in AChM3R trafficking to the cilia, associated with altered activity, suggesting that ciliary AChM3R localization is important for its activity. Vascular‐specific AChM3R and Tg737 KO mice developed high BP. Studies to examine cognitive function in our animal models are underway.ConclusionPrimary cilia play an important sensory role by hosting proteins and signaling molecules important for the regulation of blood pressure and cognitive function.