Angiotensin System Research Articles

Evaluation of Triple Whammy Prescriptions After the Implementation of a Drug Safety Algorithm.

The term triple whammy (TW) refers to the concomitant use of non-steroidal anti-inflammatory drugs, diuretics, and angiotensin system inhibitors; this combination significantly increases the risk of acute kidney injury (AKI). To prevent this serious complication, we developed an electronic algorithm that detects TW prescriptions in patients with additional risk factors such as old age and impaired kidney function. The algorithm alerts a clinical pharmacist who then evaluates and forwards the alert to the prescribing physician. We evaluated the performance of this algorithm in a retrospective observational study of clinical data from all adult patients admitted to the Cantonal Hospital of Aarau in Switzerland in 2021. We identified all patients who received a TW prescription, had a TW alert, or developed AKI during TW therapy. Algorithm performance was evaluated by calculating the sensitivity and specificity as a primary endpoint and determining the acceptance rate among clinical pharmacists and physicians as a secondary endpoint. Among 21,332 hospitalized patients, 290 patients had a TW prescription, of which 12 patients experienced AKI. Overall, 216 patients were detected by the alert algorithm, including 11 of 12 patients with AKI; the algorithm sensitivity is 88.3% with a specificity of 99.7%. Physician acceptance was high (77.7%), but clinical pharmacists were reluctant to forward the alerts to prescribers in some cases. The TW algorithm is highly sensitive and specific in identifying patients with TW therapy at risk for AKI. The algorithm may help to prevent AKI in TW patients in the future.

New insights into the role of Klotho in inflammation and fibrosis: molecular and cellular mechanisms.

As the body's defense mechanism against damage and infection, the inflammatory response is a pathological process that involves a range of inflammatory cells and cytokines. A healthy inflammatory response helps the body repair by eliminating dangerous irritants. However, tissue fibrosis can result from an overly intense or protracted inflammatory response. The anti-aging gene Klotho suppresses oxidation, delays aging, and fosters development of various organs. Numerous investigations conducted in the last few years have discovered that Klotho expression is changed in a variety of clinical diseases and is strongly linked to the course and outcome of a disease. Klotho functions as a co-receptor for FGF and as a humoral factor that mediates intracellular signaling pathways such as transforming growth factor β (TGF-β), toll-like receptors (TLRs), nuclear factor-kappaB (NF-κB), renin -angiotensin system (RAS), and mitogen-activated protein kinase (MAPK). It also interferes with the phenotype and function of inflammatory cells, such as monocytes, macrophages, T cells, and B cells. Additionally, it regulates the production of inflammatory factors. This article aims to examine Klotho's scientific advances in terms of tissue fibrosis and the inflammatory response in order to provide novel therapy concepts for fibrotic and inflammatory disorders.

Modulation of Mitochondrial Dynamics by the Angiotensin System in Dopaminergic Neurons and Microglia.

Renin-angiotensin system (RAS) dysfunctions have been associated to life-spam, and aging-related diseases, including neurodegenerative diseases, such as Parkinson's disease, and the neuroinflammatory associated processes. Mitochondrial dysfunctions play a major role in aging-related diseases, including dopaminergic neurodegeneration and neuroinflammation. However, the mechanisms of RAS/mitochondria interactions remain to be clarified. In the present work, we studied the role of major RAS components in the mitochondrial dynamics in dopaminergic neurons and microglia using in vitro and in vivo models. In dopaminergic neurons, we observed that activation of the RAS pro-oxidative/pro-inflammatory axis (Angiotensin II/Angiotensin type-1 receptor, AT1/NADPH oxidase complex) produces a dysregulation of mitochondrial dynamics towards mitochondrial fission, via Drp1 phosphorylation at Ser616 and translocation to mitochondria. However, activation of the RAS antioxidative/anti-inflammatory axis, using Angiotensin 1-7, counteracts this effect. RAS components also modulated the microglial inflammatory response through mitochondrial dynamic changes. After interferon-γ-induced activation of human microglial cells, we observed increased mitochondrial fission and superoxide production that was inhibited by Angiotensin 1-7 treatment. Angiotensin 1-7 also inhibited mitochondrial metabolic changes induced by pro-inflammatory microglial activation. The role of RAS in mitochondrial dynamic changes was confirmed in vivo using the LPS-induced inflammation model in wild-type, AT1-KO, and AT2-KO mice. The effect of Angiotensin 1-7 is mediated by IL-10, specifically by decreasing the post-transcriptional phosphorylated Drp1 form, and translocation of STAT3 to mitochondria. Angiotensin 1-7, acting on mitochondrial Angiotensin 1-7 receptors (Mas/Mas related receptors), increased the phosphorylated form of STAT3 at Ser727, which is mediated by mitochondrial PKA activation. In conclusion, the present findings show the role of RAS components in modulation of mitochondrial dynamics and mitochondrial function, revealing the associated signaling pathways. The results lead to better understanding of the effects of RAS dysfunction in aging-related diseases, and particularly dopaminergic degeneration and neuroinflammation in Parkinson's disease.

Mast cells, mediators, and symptomatic activation

<abstract> <p>Mast cells (MC) are central effectors of allergic disease and distinct subsets with varying amounts of tryptase, chymase, and carboxypeptidase A3, and cathepsin G is distributed throughout the body. Their involvement in a diverse range of non-allergic illnesses mediated by a complex range of preformed and newly synthesized mediators is now increasingly recognized. The latter especially include conditions under the umbrella term of mast cell activation syndrome. In allergic disease, much has been written about the mechanisms by which the early and rapidly acting mediators produce both localized and systemic allergic symptoms. The role of chymase is presently underappreciated but there is increased awareness that MCs contain significant amounts of preformed TNF alpha and synthesize and releases a wide range of inflammatory cytokines such as interleukins (IL) 1β, IL6, IL31, and IL33. These can aggravate itching and perpetuate inflammation and likely contribute to the late constitutional symptoms seen in allergic reactions. Importantly, their involvement helps to clarify the role of MCs in stress and non-parasitic infections. Presently, unexplained is the increasing incidence of significant acute allergic reactions within a relatively short time frame. In this context, there is increasing interest in the environmental, menstrual, endocrine, circadian, and psychological factors that influence MC activation as well as the endocrine pathways involving the renin angiotensin system that oppose hypotension. In non-allergic diseases with normal numbers of MCs, reduced thresholds for activation may be produced by various combinations of life and dietary factors. Diagnosing these conditions is difficult but may be helped by urinary analysis of prostaglandin metabolites. The investigation and management of mastocytosis with and without mutations of c-kit is also relevant to allergic disease and the new medications used may also be helpful in idiopathic anaphylaxis. This knowledge may open a new chapter in human diseases and mast cell regulation.</p> </abstract>

Correlation between Angiotensin Inhibitor Administration and Longer Survival in Patients Who Underwent Curative Resection for Pancreatic Cancer.

The microenvironment of pancreatic ductal adenocarcinoma (PDAC) with extensive desmoplastic stroma contributes to aggressive cancer behavior. Angiotensin system inhibitors (ASIs) reduce stromal fibrosis and are a promising therapeutic strategy. The purpose of this study was to examine how ASIs affected the oncological results of patients who had their PDAC removed. A retrospective assessment was conducted on the clinicopathological and survival data of patients who received curative resection for PDAC at Severance Hospital between January 2012 and December 2019. A total of 410 participants (228 male and 182 female), with a median follow-up period of 12.8 months, were included in this study. Patients were divided into three groups, based on ASI use and history of hypertension: group 1, normotensive and never used ASI (n=210, 51.2%); group 2, ASI non-users with hypertension (n=50, 12.2%); and group 3, ASI users with hypertension (n=150, 36.6%). The three groups did not differ significantly in terms of age, sex, kind of operation, T and N stages, or adjuvant and neoadjuvant therapy. Moreover, there was no discernible difference in disease-free survival between those who used ASI and those who did not (p=0.636). The 5-year overall survival (OS) rates in groups 1, 2, and 3 were 52.6%, 32.3%, and 38.0%, respectively. However, the OS rate of ASI users was remarkably higher than that of non-users (p=0.016). In patients with resected PDAC, ASI is linked to longer survival rates. Furthermore, for individuals with hypertension, ASI in conjunction with conventional chemotherapy may be an easy and successful treatment option.

Targeting the Renin-Angiotensin System (RAS) for Neuropsychiatric Disorders.

Neuropsychiatric disorders, such as mood disorders, schizophrenia, and Alzheimer's disease (AD) and related dementias, are associated to significant morbidity and mortality worldwide. The pathophysiological mechanisms of neuropsychiatric disorders remain to be fully elucidated, which has hampered the development of effective therapies. The Renin Angiotensin System (RAS) is classically viewed as a key regulator of cardiovascular and renal homeostasis. The discovery that RAS components are expressed in the brain pointed out a potential role for this system in central nervous system (CNS) pathologies. The understanding of RAS involvement in the pathogenesis of neuropsychiatric disorders may contribute to identifying novel therapeutic targets. We aim to report current experimental and clinical evidence on the role of RAS in physiology and pathophysiology of mood disorders, schizophrenia, AD and related dementias. We also aim to discuss bottlenecks and future perspectives that can foster the development of new related therapeutic strategies. The available evidence supports positive therapeutic effects for neuropsychiatric disorders with the inhibition/antagonism of the ACE/Ang II/AT1 receptor axis or the activation of the ACE2/Ang-(1-7)/Mas receptor axis. Most of this evidence comes from pre-clinical studies and clinical studies lag much behind, hampering a potential translation into clinical practice.

Solitary Functioning Kidneys Attenuate Renal Hemodynamics Responses to Angiotensin II in Male But Not in Female Rats.

People with solitary functioning kidneys (SFK) are prone to renal failure with time. Accordingly, local renin angiotensin system (RAS) and renal functions in subjects with SFK may act differently compared to normal condition. This study was designed to determine the renal hemodynamics responses to angiotensin II (Ang. II) in SFK male and female rats. Fifty to sixty-day-old male and female Wistar rats were subjected to unilateral renal artery obstruction, and 28 days later basal renal hemodynamic responses to Ang. II were examined in SFK groups compared to sham groups. The findings indicated lower renal vascular resistance (RVR) and renal blood flow (RBF) responses to Ang. II in male SFK compared to sham group. Such observation was not seen in female animals. An increase in renal metabolism due to hyperfunction, especially in SFK male rats, may cause a decrease in RVR. Moreover, the lower RBF response to Ang. II may be related to alteration to Ang. II receptors in the remnant kidneys in SFK rats.

Understanding Prescribing Practices and Patient Experiences with Renin Angiotensin System Inhibitors Use in Chronic Kidney Disease: A Qualitative Study

Introduction: Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) improve outcomes but are underutilized in patients with chronic kidney disease (CKD). Little is known about reasons for discontinuation and lack of reinitiating these medications. We aimed to explore clinicians’ and patients’ experiences and perceptions of ACEI/ARB use in CKD. Methods: A multi-profession sample of health care clinicians and patients with documented ACEI/ARB-associated side effects in the past 6 months. Participants were recruited from 2 Veterans Affairs healthcare systems in Texas and Tennessee. A total of 15 clinicians and 10 patients completed interviews. We used inductive and deductive qualitative data analysis approaches to identify themes related to clinician and patient experiences with ACEI/ARB. Thematic analysis focused on prescribing decisions and practices, clinical guidelines, and perception of side effects. Data were analyzed as they amassed, and recruitment was stopped at the point of thematic saturation. Results: Clinicians prescribe ACEI/ARB for blood pressure control and kidney protection and underscored the importance of these medications in patients with diabetes. While clinicians described providing comprehensive patient education about ACEI/ARB in CKD, patient interviews revealed significant knowledge gaps about CKD and ACEI/ARB use. Many patients were unaware of their CKD status, and some did not know why they were prescribed ACEI/ARB. Clinicians’ drug management strategies varied widely, as did their understanding of prescribing guidelines. They identified structural and patient-level barriers to prescribing and many endorsed the development of a decision support tool to facilitate ACEI/ARB prescribing and management. Discussion/Conclusion: Our qualitative study of clinicians and providers identified key target areas for improvement to increase ACEI/ARB utilization in patients with CKD with the goal to improve long-term outcomes in high-risk patients. These findings will also inform the development of a decision support tool to assist with prescribing ACEI/ARBs for patients with CKD.

Effect of renin angiotensin system inhibitors on long-term major cardiovascular outcomes in patients with high atherosclerotic cardiovascular risk

The advantage of angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in patients with preserved LV systolic function is uncertain. We aimed to investigate the effects of ACEI/ARB in high atherosclerotic risk patients without overt heart failure (HF) on long-term major cardiovascular outcomes (MACEs). The Cohort Of patients with high Risk for cardiovascular Events (CORE-Thailand) registry is a prospective, multicenter, observational, longitudinal study of Thai patients with high atherosclerotic risk. The patients with ejection fraction < 50% were excluded. Among 8513 recruited patients, there were 4246 patients included into final analysis after propensity score matching. At 5-years follow-up, Cox regression analysis showed that ACEI/ARB was significantly associated with reduced risk of all-cause mortality or non-fatal myocardial infarction, non-fatal stroke and HF hospitalization (HR 0.82, 95% CI 0.70–0.96, P = 0.011). The benefit was driven by the reduced all-cause mortality and HF. Subgroup analysis demonstrated that ACEI/ARB decreased risk of long-term MACEs in patients with diabetes (HR 0.77, 95% CI 0.63–0.94, P = 0.011) and patients not taking statin (HR 0.57, 95% CI 0.40–0.82, P = 0.002). We demonstrated that the use of ACEI/ARB was associated with reduced risk of long-term MACEs in a large cohort of high atherosclerotic risk patients. Reduction of all-cause mortality and HF were likely the main contributors to the benefit of ACEI/ARB.

Antihypertensive prescribing patterns in non-dialysis dependent chronic kidney disease: Findings from the Salford Kidney Study.

Hypertension is commonly observed in patients living with chronic kidney disease (CKD). Finding an optimal treatment regime remains challenging due to the complex bidirectional cause-and-effect relationship between hypertension and CKD. There remains variability in antihypertensive treatment practices. To analyze data from the Salford Kidney Study database in relation to antihypertensive prescribing patterns amongst CKD patients. The Salford Kidney Study is an ongoing prospective study that has been recruiting CKD patients since 2002. All patients are followed up annually, and their medical records including the list of medications are updated until they reach study endpoints [starting on renal replacement therapy or reaching estimated glomerular filtration rate (eGFR) expressed as mL/min/1.73 m2 ≤ 10 mL/min/1.73 m2, or the last follow-up date, or data lock on December 31, 2021, or death]. Data on antihypertensive prescription practices in correspondence to baseline eGFR, urine albumin-creatinine ratio, primary CKD aetiology, and cardiovascular disease were evaluated. Associations between patients who were prescribed three or more antihypertensive agents and their clinical outcomes were studied by Cox regression analysis. Kaplan-Meier analysis demonstrated differences in survival probabilities. Three thousand two hundred and thirty non-dialysis-dependent CKD patients with data collected between October 2002 and December 2019 were included. The median age was 65 years. A greater proportion of patients were taking three or more antihypertensive agents with advancing CKD stages (53% of eGFR ≤ 15 mL/min/1.73 m2 vs 26% of eGFR ≥ 60 mL/min/1.73 m2, P < 0.001). An increased number of patients receiving more classes of antihypertensive agents was observed as the urine albumin-creatinine ratio category increased (category A3: 62% vs category A1: 40%, P < 0.001), with the upward trends particularly noticeable in the number of individuals prescribed renin angiotensin system blockers. The prescription of three or more antihypertensive agents was associated with all-cause mortality, independent of blood pressure control (hazard ratio: 1.15; 95% confidence interval: 1.04-1.27, P = 0.006). Kaplan-Meier analysis illustrated significant differences in survival outcomes between patients with three or more and those with less than three antihypertensive agents prescribed (log-rank, P < 0.001). Antihypertensive prescribing patterns in the Salford Kidney Study based on CKD stage were consistent with expectations from the current United Kingdom National Institute of Health and Care Excellence guideline algorithm. Outcomes were poorer in patients with poor blood pressure control despite being on multiple antihypertensive agents. Continued research is required to bridge remaining variations in hypertension treatment practices worldwide.

Evaluation of Renin Level and Some Hormones in Patients with Polycystic Ovarian Syndrome

Polycystic Ovarian Syndrome (PCOS) is one of the most frequent gynecological endocrinopathy that occurs in premenopausal females. This study aimed to investigate the relationship between PCOS and Renin Angiotensin Aldosteron system, by measuring the levels of renin, ACE, Kallikren5, FSH and LH in follicular and luteal phase, in addition to evaluating the level of kallikrein 5, which belongs to the kallikrein-kinin system associated with the renin system. The renin-angiotensin system (RAS) is well known as regulator of electrolytes and blood pressure. Renin is previously considered a major enzyme in this system. The study included 90 blood samples for married women of childbearing age between (18-45) years. These samples included 70 samples for women with polycystic ovary syndrome, which were divided into two groups (35 samples in each one), the first was withdrawn in the follicular phase, named PA, and the second in the luteal phase of the menstrual cycle named PB. As for the remaining 20 samples, they represented the control group of healthy women, which were also divided into two groups (CA and CB) as happened with the patient group. In this study, the levels of serum Renin, ACE, LH, FSH and Kallikren5 were evaluated in PCOS patients and compared with the control group in both phases. The results were analyzed by T-Test and ROC. There were no significant differences between patients and the control group in terms of ACE activity or FSH (P&gt;0.05). The results demonstrated that LH, Renin, and Kallikren5 were higher in patient group in both phases (P&lt;0.05). Renin Angiotensin system was affected by PCOS.

Prevalence and Risk Factors for Angiotensin Converting Enzyme Inhibitor Induced Cough among Diabetic Patients in a Tertiary Institution in Southeast Nigeria

Introduction: The prevalence of diabetes mellitus (DM) is increasing worldwide, with the attendant cardiovascular morbidity and mortality especially heightened by co-existing hypertension and proteinuria. The renin–angiotensin system (RAS) has been a drug target of particular interest because of its involvement in the cardiovascular and renal disease progression. The ACE inhibitors (ACEI) have been proven effective for reducing cardiovascular events and mortality in patients with cardiovascular disease. However, these medications are associated with cough in certain subjects which could lead to poor drug adherence and increased cardiovascular morbidity and mortality. This study sought to determine the prevalence of ACEI-induced subjects in DM patients. Methodology: A total of 100 patients who fit eligibility criteria were included in the study. A questionnaire was administered on subjects who were on ACEI while data was abstracted from the medical records of subjects who had been on the medication in the preceding two years. Results: The prevalence of ACEI-induced cough was 20%. Female gender (p=0.022) and prolonged use of the medication (p=0.017) positively correlated with cough among DM subjects who had received ACEI in the preceding 2 years, or were on the medication at the time of this study. There was no correlation between the type of ACEI, anthropometry, and glycaemic control and the prevalence of cough among the subjects. Conclusion: Our study suggests that the prevalence of cough among patients with diabetes mellitus who have been exposed to ACEI is substantial. Keywords: ACE inhibitors; cough; diabetes mellitus.

Pea protein hydrolysate reduces blood glucose in high-fat diet and streptozotocin-induced diabetic mice.

Food proteins have been recognized as an ideal source to release bioactive peptides with the potential to intervene nutrition related chronic diseases, such as cardiovascular diseases, obesity and diabetes. Our previous studies showed that pea protein hydrolysate (PPH) could suppress hepatic glucose production in hepatic cells via inhibiting the gluconeogenic signaling. Thus, we hypothesized that PPH could play the hypoglycemic role in vivo. In the present study, the mice model with type 2 diabetic mellitus (T2DM) was developed by high-fat diet and low dose of streptozotocin injections. PPH was administered orally with a dosage of 1000 mg/kg body weight for 9 weeks, followed by the downstream biomedical analyses. The results showed that the 9-week treatment of PPH could reduce fasting blood glucose by 29.6% and improve glucose tolerance in the T2DM mice. The associated mechanisms included suppression of the gluconeogenic pathway, activation of the insulin signaling and modulation of the renin angiotensin system in the liver of the diabetic mice. In addition, the levels of pro-inflammatory markers in both liver and serum were reduced by the PPH treatment. The hypoglycemic effect of PPH in T2DM mice was demonstrated in the present study. Findings from this study could provide rationale to incorporate PPH into functional foods or nutraceuticals for glycemic control.

The Use of Renin-Angiotensin System Blockades Among Patients with Chronic Kidney Disease

Background and objectives: Hypertension is common in adult patients with chronic kidney disease with a prevalence that depends on the stage and etiology of chronic kidney disease and has been reported to range from 60-90%. The aim of this study was to evaluate the clinical use of renin angiotensin system blockers in chronic kidney disease patients and to identify their potential indications, contraindications and side effects amongst different clinical specialties in relation to their clinical outcomes. Methods: This study was a descriptive cross sectional based on self-administered online questionnaire, 133 medical doctors from different specialties including nephrologists, internists, urologists, general practitioners responded to the questionnaire and filled it up, which was composed of three main parts including the socio-demographic data of the participants, data about CKD and its stages and finally the RAS blockades. The study extended from June until July 2021. Results: The mean age ± standard deviation of respondents was 44.65 ± 6.89 years. Nearly one third of the respondents were internist, 12.8% nephrologist, 7.5% urologist and 45.9% from other different specialties. The vast majority (98.5%) of the physicians thought that renin angiotensin system inhibitors are effective anti-hypertensive agents even for chronic kidney disease patients. Most of the nephrologists and other specialties would continue the renin angiotensin system inhibitors while most of the internists and urologists would either stop or change the renin angiotensin system inhibitors, this was statistically significant and p–value was 0.010.

Adapting Clinical Practice Guidelines for Chronic Kidney Disease: Blood Pressure Management and Kidney Replacement Therapy in Adults and Children in the Saudi Arabian Context Using the Grading of Recommendations Assessment, Development, and Evaluation-ADOLOPMENT Methodology.

This practice guideline was developed by the chronic kidney disease (CKD) Task Force, which was composed of clinical and methodological experts. The Saudi Arabian Ministry of Health and its health holding company commissioned this guideline project to support the realization of Vision 2030's health-care transformation pillar. The synthesis of these guidelines was guided by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE)- ADOLOPMENT methodology. The final guidelines addressed 12 clinical questions on the management of blood pressure in patients with CKD through a set of recommen-dations and performance measures. The recom-mendations included antihypertensive agents in children; renin- angiotensin system inhibition (RASi) versus non-RASi in adults; intensive versus standard blood pressure targets; early versus late assessment for kidney replacement therapy (KRT); late versus early preparation strategies for KRT; CKD symptoms during assessment for KRT or conservative manage-ment; initiation of KRT in patients with deteriorating CKD; choice of KRT modality or conservative management in certain CKD patient groups; changing or discontinuing KRT modalities; the frequency of reviews for KRT or conservative management; and information, education, and support. These conditional recommendations were based on a low to very low certainty of evidence, which highlights the need for high-quality randomized trials com-paring different antihypertensive agents in patients with CKD.

Association between the use of antihypertensive medication and amyloid‐beta deposition in older adults with hypertension

AbstractBackgroundRecent evidences suggest that the use of antihypertensive medications (HTNmed) may decrease the incidence of Alzheimer’s disease (AD) dementia. We investigated whether the use of HTNmed is associated with in vivo AD pathologies, particularly cerebral beta‐amyloid (Aβ) deposition, and whether the relationship between HTNmed and cerebral Aβ deposition differs according to the characteristics of HTNmed in older adults.MethodParticipants were recruited from the Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer’s Disease (KBASE) cohort. Both cognitively normal and cognitively impaired older adults (age range: 55‐90 years) who met the following criteria of hypertension (HTN) were included for this study: i) clinical diagnosis of hypertension or ii) systolic blood pressure higher than 130mmHg or diastolic blood pressure higher than 80mmHg measured at baseline. All participants underwent comprehensive clinical assessment and [11C] Pittsburgh Compound B positron emission tomography PET for measuring Aβ deposition.ResultAmong total 413 older adults with hypertension, 227(54.8%) were taking HTNmed. Overall, individuals taking HTNmed showed significantly lower Aβ deposition compared to those without HTNmed (B = ‐0.104, p = 0.007), even after controlling age, sex, apolipoprotein E e4 positivity, and mean arterial blood pressure(MAP). Drug‐class specific analyses showed that the use of renin angiotensin system (RAS) inhibitor (i.e., angiotensin converting enzyme inhibitor and angiotensin receptor blocker) was associated with less cerebral Aβ deposition among older adults with HTNmed (B = ‐0.142, p = 0.006), but the use of other HTNmeds was not. In addition, the blood‐brain barrier permeability of HTNmed also did not have any relationship with Aβ deposition.ConclusionThe present finding suggests that the use of HTNmed, particularly RAS inhibitor, is associated with less Aβ deposition in older adults with hypertension. Further studies to explore the mechanism underlying the effect of RAS inhibitor on Aβ accumulation may provide clues for new therapeutic targets of AD.

Preclinical Evidence for the Role of the Yin/Yang Angiotensin System Components in Autism Spectrum Disorder: A Therapeutic Target of Astaxanthin.

Autism spectrum disorder (ASD) prevalence is emerging with an unclear etiology, hindering effective therapeutic interventions. Recent studies suggest potential renin-angiotensin system (RAS) alterations in different neurological pathologies. However, its implications in ASD are unexplored. This research fulfills the critical gap by investigating dual arms of RAS and their interplay with Notch signaling in ASD, using a valproic acid (VPA) model and assessing astaxanthin's (AST) modulatory impacts. Experimentally, male pups from pregnant rats receiving either saline or VPA on gestation day 12.5 were divided into control and VPA groups, with subsequent AST treatment in a subset (postnatal days 34-58). Behavioral analyses, histopathological investigations, and electron microscopy provided insights into the neurobehavioral and structural changes induced by AST. Molecular investigations of male pups' cortices revealed that AST outweighs the protective RAS elements with the inhibition of the detrimental arm. This established the neuroprotective and anti-inflammatory axes of RAS (ACE2/Ang1-7/MasR) in the ASD context. The results showed that AST's normalization of RAS components and Notch signaling underscore a novel therapeutic avenue in ASD, impacting neuronal integrity and behavioral outcomes. These findings affirm the integral role of RAS in ASD and highlight AST's potential as a promising treatment intervention, inviting further neurological research implications.

Genotype AA of ACE2 G8790A (rs2285666) Has Protective Potential Against COVID-19 Disease Severity

Background: SARS-CoV-2 virus uses angiotensin converting enzyme 2 (ACE2), a key enzyme of the renin angiotensin system (RAS) as the functional receptor for cell fusion and induction of infections in the respiratory system. Functional ACE2 gene polymorphisms may lead to RAS imbalance and are associated with COVID-19 susceptibility and severity. ACE2 G8790A (rs2285666), a splice region variant, is well characterized in various populations across the world. In the present study, the role of ACE2 G8790A (rs2285666) variant as risk predictor for severity of COVID-19 infection was investigated.Materials and methods: One-hundred COVID-19 subjects were included in the study and divided into: subjects with a history of severe infection and ICU-admitted (Group 1) and subjects with mild to moderate COVID-19 infection (Group 2). Genotype analysis for rs2285666 of ACE2 was performed using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method.Results: The distribution of ACE2 G8790A (rs2285666) genotypes were GG 62%, GA 18%, and AA 20% in Group 1 and GG 34%, GA 14%, and AA 52% in Group 2, respectively. The A allele of rs2285666 (p≤0.001; OR=3.4; 95% CI=1.89–6.107) were less frequent in Group 1 as compared to Group 2. Also, a statistically significant difference was found between severity of COVID-19 infection with age and comorbidities such as diabetes, hypertension, chronic kidney disease, but not gender.Conclusion: Our findings suggest the possibility of a protective mechanism of the AA genotype of ACE2 G8790A (rs2285666) variant against COVID-19 disease severity.Keywords: COVID-19, ACE2 gene, renin-angiotensin system, genetic association, rs2285666, sanger sequencing

Role of brain renin-angiotensin system in depression: A new perspective.

Depression is a mood disorder characterized by abnormal thoughts. The pathophysiology of depression is related to the deficiency of serotonin (5HT), which is derived from tryptophan (Trp). Mitochondrial dysfunction, oxidative stress, and neuroinflammation are involved in the pathogenesis of depression. Notably, the renin-angiotensin system (RAS) is involved in the pathogenesis of depression, and different findings revealed that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may be effective in depression. However, the underlying mechanism for the role of dysregulated brain RAS-induced depression remains speculative. Therefore, this review aimed to revise the conceivable role of ACEIs and ARBs and how these agents ameliorate the pathophysiology of depression. Dysregulation of brain RAS triggers the development and progression of depression through the reduction of brain 5HT and expression of brain-derived neurotrophic factor (BDNF) and the induction of mitochondrial dysfunction, oxidative stress, and neuroinflammation. Therefore, inhibition of central classical RAS by ARBS and ACEIs and activation of non-classical RAS prevent the development of depression by regulating 5HT, BDNF, mitochondrial dysfunction, oxidative stress, and neuroinflammation.

Association of Active Renin Content With Mortality in Critically Ill Patients: A Post hoc Analysis of the Vitamin C, Thiamine, and Steroids in Sepsis (VICTAS) Trial.

Sepsis is a leading cause of mortality. Predicting outcomes is challenging and few biomarkers perform well. Defects in the renin-angiotensin system (RAS) can predict clinical outcomes in sepsis and may outperform traditional biomarkers. We postulated that RAS dysfunction (elevated active renin, angiotensin 1-7 [Ang-(1-7)], and angiotensin-converting enzyme 2 (ACE2) activity with depressed Ang-II and ACE activity) would be associated with mortality in a cohort of septic patients. Post hoc analysis of patients enrolled in the Vitamin C, Thiamine, and Steroids in Sepsis (VICTAS) randomized controlled trial. Forty-three hospitals across the United States. Biorepository samples of 103 patients. We analyzed day 0 (within 24 hr of respiratory failure, septic shock, or both) and day 3 samples ( n = 103 and 95, respectively) for assessment of the RAS. The association of RAS values with 30-day mortality was determined using Cox proportional hazards regression with multivariable adjustments for age, sex, VICTAS treatment arm, systolic blood pressure, Sequential Organ Failure Assessment Score, and vasopressor use. High baseline active renin values were associated with higher 30-day mortality when dichotomized to the median of 188.7 pg/mL (hazard ratio [HR] = 2.84 [95% CI, 1.10-7.33], p = 0.031) or stratified into quartiles (Q1 = ref, HR Q2 = 2.01 [0.37-11.04], HR Q3 = 3.22 [0.64-16.28], HR Q4 = 5.58 [1.18-26.32], p for linear trend = 0.023). A 1- sd (593.6 pg/mL) increase in renin from day 0 to day 3 was associated with increased mortality (HR = 3.75 [95% CI, 1.94-7.22], p < 0.001), and patients whose renin decreased had improved survival compared with those whose renin increased (HR 0.22 [95% CI, 0.08-0.60], p = 0.003). Ang-(1-7), ACE2 activity, Ang-II and ACE activity did not show this association. Mortality was attenuated in patients with renin over the median on day 0 who received the VICTAS intervention, but not on day 3 ( p interaction 0.020 and 0.137, respectively). There were no additional consistent patterns of mortality on the RAS from the VICTAS intervention. Baseline serum active renin levels were strongly associated with mortality in critically ill patients with sepsis. Furthermore, a greater relative activation in circulating renin from day 0 to day 3 was associated with a higher risk of death.