Renin-angiotensin-aldosterone (RAAS): The ubiquitous system for homeostasis and pathologies

The role of sex hormones in aldosterone biosynthesis and their potential impact on its mineralocorticoid receptor

Blood pressure (BP) regulation is a complex process involving various hormones, including aldosterone and its mineralocorticoid receptor. Mineralocorticoid receptor is expressed in several tissues, including the kidney, and plays a crucial role in regulating BP by controlling the sodium and water balance. During different stages of life, hormonal changes can affect mineralocorticoid receptor activity and aldosterone levels, leading to changes in BP. Increasing evidence suggests that sex steroids modulate aldosterone levels. Estrogens, particularly estradiol, mediate aldosterone biosynthesis by activating classical estrogen receptors and the G protein-coupled receptor. Progesterone acts as an anti-mineralocorticoid by inhibiting the binding of aldosterone to the mineralocorticoid receptor. Moreover, progesterone inhibits aldosterone synthase enzymes. The effect of testosterone on aldosterone synthesis is still a subject of debate. However, certain studies show that testosterone downregulates the mRNA levels of aldosterone synthase, leading to decreased plasma aldosterone levels.

Are Hair Scalp Trace Elements Correlated with Atherosclerosis Location in Coronary Artery Disease?

Coronary artery disease is among the leading current epidemiological challenges. The genetic, clinical, and lifestyle-related risk factors are well documented. The reason for specific epicardial artery locations remains unsolved. The coronary artery topography and blood flow characteristics may induce local inflammatory activation. The atherosclerotic plaque formation is believed to represent inflammatory response involving enzymatic processes co-factored by trace elements. The possible relation between trace elements and coronary artery disease location was the subject of the study. There were 175 patients (107 (61) men and 68 (39) females) in a median (Q1-3) age of 71 years (65-76) admitted for coronary angiography due to chronic coronary syndrome. The angiographic results focused on the percentage of lumen stenosis in certain arteries and were compared with the results for hair scalp trace elements. The correlation between left main coronary artery atherosclerotic plaques and nickel (Ni), zinc (Zn), and antimony (Sb) hair scalp concentration was noted. The analysis revealed a positive relation between left descending artery disease and chromium (Cr), sodium (Na), arsenic (As), and molybdenum (Mo) and a negative correlation with strontium (Sr). The atherosclerotic lesion in the circumflex artery revealed correlations in our analysis with sodium (Na), potassium (K), chromium (Cr), nickel (Ni), arsenic (As), and negative with strontium (Sr) (r) hair scalp concentrations. The negative correlations between right coronary artery disease and magnesium (Mg) and strontium (Sr) concentrations were noted. The possible explanation of different epicardial artery involvement and severity by atherosclerotic processes may lay in their topography and blood rheological characteristics that induce different inflammatory reactions co0factored by specific trace elements. The trace element concentration in the hair scalp may correlate with a particular coronary atherosclerotic involvement, including the severity of lumen reduction. This may indicate the missing link between the pathophysiological processes of atherosclerosis development and its location in coronary arteries.

Assessment of per- and poly-fluoroalkyl substances and physiological biomarkers in aquarium-based bottlenose dolphins and killer whales

Environmental concerns about per- and polyfluoroalkyl substances (PFAS) are considerably increasing due to their extensive use in commercial and consumer products. PFAS bioaccumulate and biomagnify throughout the food chain, and their toxicity and potential adverse health effects can potentially represent a threat to living organisms. In this study, we described PFAS profiles in the serum of two species of zoo-based bottlenose dolphins (Tursiops truncatus, n = 14 individuals) and killer whales (Orcinus orca, n = 14 individuals) from three locations (California, Florida, and Texas, USA), from 1994 to 2020. Potential physiological effects of PFAS were also explored by measuring different biomarkers (cortisol, corticosterone, aldosterone, TBARS, and hydrogen peroxide) while accounting for individual age, sex, and reproductive stage. All PFAS were detected in at least one of the individuals, considering both species. ΣPFAS reached 496 ng mL-1 in bottlenose dolphins and 230 ng mL-1 in killer whales. In both species, the PFAS with higher mean concentrations were PFOS (108.0-183.0 ng ml-1) and PFNA (14.40-85.50 ng ml-1), which are long-chain compounds. Newborn individuals of both species were also exposed to PFAS, indicating transference via placenta and lactation. Linear mixed model analyses indicated significant correlations between aldosterone, month, year, location, and status; and between hydrogen peroxide, month, year, age, status, ΣPFAS, and Σ short-chain PFAS in killer whales suggesting seasonal variations related to the animal's physiological state (e.g., reproductive cycles, stress responses, weaning events) and increased reactive oxygen species formation due to PFAS exposure. Given our results, other contaminant classes should be investigated in cetaceans as they might have additive and synergistic detrimental effects on these individuals. This study lays the foundation to guide future researchers and highlights the importance of such assessments for animal welfare, and species conservation. Our results may inform management decisions regarding regulations of contaminant thresholds in delphinids.

Gene expression in heart, kidney, and liver identifies possible mechanisms underpinning fetal resistance and susceptibility to in utero PRRSV infection

Porcine reproductive and respiratory syndrome (PRRS) is one of the costliest diseases to pork producers worldwide. We tested samples from the pregnant gilt model (PGM) to better understand the fetal response to in-utero PRRS virus (PRRSV) infection. Our goal was to identify critical tissues and genes associated with fetal resilience or susceptibility. Pregnant gilts (N=22) were infected with PRRSV on day 86 of gestation. At 21 days post maternal infection, the gilts and fetuses were euthanized, and fetal tissues collected. Fetuses were characterized for PRRS viral load in fetal serum and thymus, and preservation status (viable or meconium stained: VIA or MEC). Fetuses (N=10 per group) were compared: uninfected (UNIF; <1 log/µL PRRSV RNA), resilient (HV_VIA, >5 log virus/µL but viable), and susceptible (HV_MEC, >5 log virus/µL with MEC). Gene expression in fetal heart, kidney, and liver was investigated using NanoString transcriptomics. Gene categories investigated were hypothesized to be involved in fetal response to PRRSV infection: renin- angiotensin-aldosterone, inflammatory, transporter and metabolic systems. Following PRRSV infection, CCL5 increased expression in heart and kidney, and ACE2 decreased expression in kidney, each associated with fetal PRRS susceptibility. Liver revealed the most significant differential gene expression: CXCL10 decreased and IL10 increased indicative of immune suppression. Increased liver gene expression indicated potential associations with fetal PRRS susceptibility on several systems including blood pressure regulation (AGTR1), energy metabolism (SLC16A1 and SLC16A7), tissue specific responses (KL) and growth modulation (TGFB1). Overall, analyses of non-lymphoid tissues provided clues to mechanisms of fetal compromise following maternal PRRSV infection.

Angiotensinergic effect of β-Caryophyllene on Lipopolysaccharide- induced systemic inflammation

Renin-Angiotensin System (RAS) is a peptidergic system, canonically known for its role in blood pressure regulation. Furthermore, a non-canonical RAS regulates pathophysiological phenomena, such as inflammation since it consists of two main axes: the pro-inflammatory renin/(pro)renin receptor ((P)RR) axis, and the anti-inflammatory angiotensin-converting enzyme 2 (ACE2)/Angiotensin-(1-7) (Ang-(1-7))/Mas Receptor (MasR) axis. Few phytochemicals have shown to exert angiotensinergic and anti-inflammatory effects through some of these axes; nevertheless, anti-inflammatory drugs, such as phytocannabinoids have not been studied regarding this subject. Among phytocannabinoids, β-Caryophyllene stands out as a dietary phytocannabinoid with antiphlogistic activity that possess a unique sesquiterpenoid structure. Although its cannabinergic effect has been studied, its angiotensinergic effect reminds underexplored. This study aims to explore the angiotensinergic effect of β-Caryophyllene on inflammation and stress at a systemic level. After intranasal Lipopolysaccharide (LPS) installation and oral treatment with β-Caryophyllene, the concentration and activity of key RAS elements in the serum, such as Renin, ACE2 and Ang-(1-7), along with the stress hormone corticosterone and pro/anti-inflammatory cytokines, were measured in mice serum. The results show that β-Caryophyllene treatment modified RAS levels by increasing Renin and Ang-(1-7), alongside the reduction of pro-inflammatory cytokines and corticosterone levels. These results indicate that β-Caryophyllene exhibits angiotensinergic activity in favor of anti-inflammation.

Evidence of a causal relationship between blood pressure and pathological scars: a bidirectional Mendelian randomization study

Background

Recent advancements in basic medicine and epidemiology suggest a potential influence of blood pressure on scar formation, yet the specifics of this relationship are not fully understood. This study aims to clarify the causal link between blood pressure and the development of pathological scars using Mendelian randomization (MR).

Methods

This study employed genetic variants closely linked to blood pressure as instrumental variables to explore the relationship between blood pressure and pathological scars. The inverse variance weighted (IVW) method was used for analysis.

Results

Our analysis identified a notable association where higher blood pressure was correlated with a lower risk of pathological scars. Specifically, an increase in diastolic blood pressure (odds ratio [OR] per standard deviation increase: 0.67 [95% Confidence Interval [CI], 0.49-0.99]), systolic blood pressure (OR per standard deviation increase: 0.66 [95% CI, 0.46-0.93]), and hypertension (pooled OR: 0.39 [95% CI, 0.18-0.85]) were significantly associated with a reduced risk of keloids. Similarly, a genetic predisposition to hypertension (pooled OR: 0.31 [95% CI, 0.11-0.89]) was significantly associated with a reduced risk of hypertrophic scars. Neither reverse MR analysis nor Steiger's test indicated a significant reverse causal relationship between hypertension and either keloids or hypertrophic scars.

Conclusion

The findings suggest a protective role of higher blood pressure against the development of pathological scars, including keloids and hypertrophic scars. However, the inconsistency observed across different MR methods warrants cautious interpretation and underscores the need for further investigation to confirm these findings.

Moderating effect of a sodium-rich diet on the association between long-term exposure to fine particulate matter and blood lipids in children and adolescents

BACKGROUND

Several studies reported that exposure to higher levels of fine particulate matter (PM2.5) was associated with deteriorated lipid profiles in children and adolescents. However, whether a sodium-rich diet could modify the associations remains unknown. We aimed to examine the associations of long-term exposure to PM2.5 with blood lipids in children and adolescents, and further examine the effect modification by dietary and urinary sodium levels based on a multi-community population in China.

METHODS

The 3711 study participants were from a cross-sectional study, which interviewed children and adolescents aged 6 to 17 years across Sichuan Province, China between 2015 and 2017. Blood lipid outcomes including blood total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were assessed. Information on daily dietary sodium consumption was estimated with a semi-quantitative food frequency questionnaire (FFQ), and urinary sodium was used as an internal exposure biomarker. A linear regression model was applied to estimate the associations of prior 2-years' average exposure to ambient PM2.5 with blood lipids. The effect modification by dietary and urinary sodium was examined by stratified analyses.

RESULTS

The participants from rural areas had higher levels of daily sodium consumptions. The results of multivariable regression analysis indicated that per 10 μg/m3 incremental change in PM2.5 was associated with a 1.56% (95% confidence interval 0.90%-2.23%) and a 2.26% (1.15%-3.38%) higher blood TC and LDL-C levels, respectively. Among the study participants with higher levels of dietary sodium or urinary sodium, exposure to higher levels of PM2.5 was significantly associated with deteriorated lipid profiles. For example, each 10 μg/m3 incremental change in exposure to PM2.5 was correlated with a 2.83 (-4.65 to -0.97) lower percentage decrease in blood HDL-C levels among the participants who were from the highest quartile of urinary sodium levels. While, these associations changed to be nonsignificant in the participants who were from the lowest quartile of dietary sodium levels.

CONCLUSION

Exposure to higher levels of PM2.5 was associated with deteriorated blood lipid levels in children and adolescents. It is noteworthy that these associations might be ameliorated through the adoption of a low-sodium dietary regimen.

Phytomedical compounds as promising therapeutic agents for COVID-19 targeting angiotensin-converting enzyme 2: a review

AIMS

The aim of the present review was to highlight natural product investigations in silico and in vitro to find plants and chemicals that inhibit or stimulate angiotensin-converting enzyme 2 (ACE-2).

BACKGROUND

The global reduction of incidents and fatalities attributable to infections with SARS-CoV-2 is one of the most public health problems. In the absence of specific therapy for coronavirus disease 2019 (COVID-19), phytocompounds generated from plant extracts may be a promising strategy worth further investigation, motivating researchers to evaluate the safety and anti-SARS-CoV-2 effectiveness of these ingredients.

OBJECTIVE

To review phytochemicals in silico for anti-SARS-CoV-2 activity and to assess their safety and effectiveness in vitro and in vivo.

METHODS

The present review was conducted using various scientific databases and studies on anti-SARS-CoV-2 phytochemicals were analyzed and summarized. The results obtained from the in silico screening were subjected to extraction, isolation, and purification. The in vitro studies on anti-SarcoV-2 were also included in this review. In addition, the results of this research were interpreted, analyzed, and documented on the basis of the bibliographic information obtained.

RESULTS

This review discusses recent research on using natural remedies to cure or prevent COVID-19 infection. The literature analysis shows that the various herbal preparations (extracts) and purified compounds can block the replication or entrance of the virus directly to carry out their anti-SARS-CoV-2 effects. It is interesting to note that certain items can prevent SARS-CoV-2 from infecting human cells by blocking the ACE-2 receptor or the serine protease TMPRRS2. Moreover, natural substances have been demonstrated to block proteins involved in the SARS-CoV-2 life cycle, such as papain- or chymotrypsin-like proteases.

CONCLUSION

The natural products may have the potential for use singly or in combination as alternative drugs to treat/prevent COVID-19 infection, including blocking or stimulating ACE-2. In addition, their structures may provide indications for the development of anti-SARS-CoV-2 drugs.

Association between the triglyceride glucose index and the risk of acute kidney injury in critically ill patients with hypertension: analysis of the MIMIC-IV database

Background

The triglyceride glucose (TyG) index, a metric computed from the levels of fasting triglyceride (TG) and fasting plasma glucose (FPG), has emerged as a simple surrogate measure for insulin resistance (IR) in recent years. In multiple critical care scenarios, such as contrast-induced acute kidney injury (AKI) and cardiorenal syndrome, a high TyG index levels shows a notable correlation with AKI incidence. However, its predictive value for AKI in critically ill hypertensive patients remains uncertain.

Methods

Participants were selected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and divided into quartiles based on the TyG index. The primary focus of the study was to investigate the risk of acute kidney injury (AKI), with in-hospital mortality as a secondary endpoint, assessed among all study subjects as well as specifically among AKI patients. The use of renal replacement therapy (RRT), indicative of AKI progression, was also considered a secondary endpoint reflecting renal outcomes. To explore the correlation between the TyG index and AKI risk in critically ill hypertensive patients, the study employed a restricted cubic splines model and Cox proportional hazards (CPH) models. Additionally, Kaplan-Meier survival analysis was utilized to assess differences in primary and secondary outcomes across groups categorized by their TyG index. Analyses were conducted to ensure the consistency of the predictive capability of TyG index across various subgroups.

Results

Our study included 4,418 participants, with 57% being male patients. AKI occurred in 56.1% of cases. Through the CPH analysis, we identified a significant association between the TyG index and AKI occurrence in critically ill hypertensive patients. With the help of a restricted cubic splines model, we observed a direct relationship between an elevated TyG index and an increased AKI. Subgroup examinations consistently proved the predictive value of the TyG index across categories. Furthermore, Kaplan-Meier survival analysis revealed notable differences in RRT among AKI patients.

Conclusion

The findings underscore the importance of the TyG index as a reliable predictor for the occurrence of AKI and adverse renal outcomes among hypertensive patients in critical ill states. Nevertheless, validating causality mandates extensive prospective investigations.

The Angiotensin Metabolite His-Leu Is a Strong Copper Chelator Forming Highly Redox Active Species

His-Leu is a hydrolytic byproduct of angiotensin metabolism, whose concentration in the bloodstream could be at least micromolar. This encouraged us to investigate its Cu(II) binding properties and the concomitant redox reactivity. The Cu(II) binding constants were derived from isothermal titration calorimetry and potentiometry, while identities and structures of complexes were obtained from ultraviolet-visible, circular dichroism, and room-temperature electronic paramagnetic resonance spectroscopies. Four types of Cu(II)/His-Leu complexes were detected. The histamine-like complexes prevail at low pH. At neutral and mildly alkaline pH and low Cu(II):His-Leu ratios, they are superseded by diglycine-like complexes involving the deprotonated peptide nitrogen. At His-Leu:Cu(II) ratios of ≥2, bis-complexes are formed instead. Above pH 10.5, a diglycine-like complex containing the equatorially coordinated hydroxyl group predominates at all ratios tested. Cu(II)/His-Leu complexes are also strongly redox active, as demonstrated by voltammetric studies and the ascorbate oxidation assay. Finally, numeric competition simulations with human serum albumin, glycyl-histydyl-lysine, and histidine revealed that His-Leu might be a part of the low-molecular weight Cu(II) pool in blood if its abundance is >10 μM. These results yield further questions, such as the biological relevance of ternary complexes containing His-Leu.

Persistent Vascular Complications in Long COVID: The Role of ACE2 Deactivation, Microclots, and Uniform Fibrosis

Angiotensin-converting enzyme 2 (ACE2), a key regulator in vasoregulation and the renin-angiotensin system, is hypothesized to be downregulated in patients with COVID-19, leading to a cascade of cardiovascular complications. This deactivation potentially results in increased blood pressure and vessel injury, contributing to the formation and persistence of microclots in the circulation. Herein, we propose a hypothesis regarding the prolonged vascular complications observed in long COVID, focusing on the role of ACE2 deactivation and/or shedding, the persistence of microclots, and the unique pattern of fibrosis induced by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Furthermore, we propose that the distinctive, uniform fibrosis associated with COVID-19, which is challenging to detect through conventional X-ray imaging, exacerbates vascular injury and impairs oxygenation. The persistence of these microclots and the unique fibrosis pattern are suggested as key factors in the extended duration of vascular complications post-COVID-19 infection, regardless of the initial disease severity. Moreover, plasma ACE2 activity has the potential to serve as prognostic or diagnostic biomarkers for monitoring disease severity and managing long COVID symptoms. Elucidating the role of ACE2 deactivation and the consequent events is vital for understanding the long-term effects of COVID-19. The experimental verification of this hypothesis through in vitro studies, clinical longitudinal studies, and advanced imaging techniques could yield significant insights into the pathophysiological mechanisms underlying long COVID, thereby improving the management of patients, particularly those with cardiovascular complications.

Get reliable laboratory findings - how to recognize the deceptive effects of angiotensin-converting enzyme inhibitor therapy in the laboratory diagnostics of sarcoidosis?

OBJECTIVES

Serum angiotensin-converting enzyme (ACE) is the only biomarker routinely used in the laboratory diagnostics of sarcoidosis, and ACE inhibitor (ACEi) drugs are among the most prescribed drugs worldwide. Taking ACEi can mislead medical teams by lowering ACE activity, delaying diagnosis and giving a false impression of disease activity of sarcoidosis. We aimed to develop a simple method to detect the presence of ACEi drugs in samples, to investigate the ACEi medication-caused interference and consequences in a retrospective study.

METHODS

ACE activity and the level of ACE inhibition were determined for 1823 patients with suspected sarcoidosis. These values were compared with the therapeutic information at the first and follow-up visits.

RESULTS

A total of 302 patients had biochemical evidence of an ACEi drug effect during diagnostic ACE activity testing. In their case, ACE activity was significantly lower (median(IQR): 4.41 U/L(2.93-6.72)) than in patients not taking ACEi (11.32 U/L(8.79-13.92), p<0.01). In 62 sarcoidosis patients, the ACEi reduced ACE activity to the reference range or below. Only in 40 % of the cases was the medication list recorded in the outpatient chart and only in 3 cases was low ACE activity associated with ACEi use. 67 % of the repeated ACE activity measurements were also performed during ACEi therapy.

CONCLUSIONS

Our study revealed that the use of ACEi is common in patients with suspected sarcoidosis. The ACE activity lowering effect of ACEi drugs may escape the attention of medical teams which can lead to diagnostic errors and unnecessary tests. Nevertheless, these pitfalls can be avoided by using a method suggested by our team.

Cell type-specific expression of angiotensin receptors in the human lung with implications for health, aging, and chronic disease

The renin-angiotensin system is a highly characterized integrative pathway in mammalian homeostasis whose clinical spectrum has been expanded to lung disorders such as chronic obstructive pulmonary disease (COPD)-emphysema, idiopathic pulmonary fibrosis (IPF), and COVID pathogenesis. Despite this widespread interest, specific localization of this receptor family in the mammalian lung is limited, partially due to the imprecision of available antibody reagents. In this study, we establish the expression pattern of the two predominant angiotensin receptors in the human lung, AGTR1 and AGTR2, using complementary and comprehensive bulk and single-cell RNA-sequence datasets that are publicly available. We show these two receptors have distinct localization patterns and developmental trajectories in the human lung, pericytes for AGTR1 and a subtype of alveolar epithelial type 2 cells for AGTR2. In the context of disease, we further pinpoint AGTR2 localization to the COPD-associated subpopulation of alveolar epithelial type 2 (AT2B) and AGTR1 localization to fibroblasts, where their expression is upregulated in individuals with COPD, but not in individuals with IPF. Finally, we examine the genetic variation of the angiotensin receptors, finding AGTR2 associated with lung phenotype (i.e., cystic fibrosis) via rs1403543. Together, our findings provide a critical foundation for delineating this pathway's role in lung homeostasis and constructing rational approaches for targeting specific lung disorders.

A comprehensive exploration of novel biomarkers for the early diagnosis of aortic dissection

Aortic dissection (AD) is a catastrophic life-threatening cardiovascular emergency with a 1-2% per hour mortality rate post-diagnosis, characterized physiologically by the separation of aortic wall layers. AD initially presents as intense pain that can then radiate to the back, arms, neck, or jaw along with neurological deficits like difficulty in speaking, and unilateral weakness in some patients. This spectrum of clinical features associated with AD is often confused with acute myocardial infarction, hence leading to a delay in AD diagnosis. Cardiac and vascular biomarkers are structural proteins and microRNAs circulating in the bloodstream that correlate to tissue damage and their levels become detectable even before symptom onset. Timely diagnosis of AD using biomarkers, in combination with advanced imaging diagnostics, will significantly improve prognosis by allowing earlier vascular interventions. This comprehensive review aims to investigate emerging biomarkers in the diagnosis of AD, as well as provide future directives for creating advanced diagnostic tools and imaging techniques.

Quantification of endogenous Angiotensin 1-10, 1-9, 1-8, 1-7, and 1-5 in human plasma using micro-UHPLC-MS/MS: Outlining the importance of the pre-analytics for reliable results

Angiotensin peptides (ANGs) play a central role in the renin-angiotensin-aldosterone system, rendering them interesting biomarkers associated with hypertension. Precise quantification of circulating ANGs holds the potential to assess the activity of angiotensin-converting enzyme (ACE), a key protease targeted by widely prescribed drugs, namely ACE inhibitors. This ability could pave the way for personalised medicine, offering insights into the prescription of inhibitors targeting either the proteases or the receptors within the system. Despite recent developments in liquid chromatography-mass spectrometry (LC-MS) methods for measuring circulating ANG concentrations, comprehensive stability studies of ANGs in human plasma are absent in the literature, raising concerns about the reliability of measured concentrations and their link to clinical conditions. To address this critical gap, we conducted an exhaustive evaluation of the pre-analytical stability of ANG1-10, ANG1-9, ANG1-8, ANG1-7, and ANG1-5. By employing surfactants to mitigate non-specific adsorption and a dedicated mix of protease inhibitors to limit protease activity, we established an MS-based assay for these five peptides. We used this method to quantify circulating concentrations of ANGs in the plasma of 11 healthy donors and 3 patients under kidney dialysis. Our findings revealed that ANG1-10 and ANG1-8 circulate at concentrations ranging from 1 to 10 pM in healthy subjects and exhibit a high degree of correlation. Notably, ANG1-9, ANG1-7, and ANG1-5 were undetectable in any of the 14 patients, despite a sub-picomolar limit of detection. This strikingly contrasts with the reference concentrations reported in the literature, which typically fall within the picomolar range. In light of these discrepancies, we strongly advocate for rigorous pre-analytical considerations and comprehensive stability studies to ensure reliable results. We emphasise the pivotal role of heightened pre-analytical awareness within the clinical chemistry community, and we hope for continued growth in this critical area.

Angiotensin receptor blocker-neprilysin inhibitor for heart failure with reduced ejection fraction

Heart failure with reduced ejection fraction (HFrEF) is a clinical syndrome characterized by volume overload, impaired exercise capacity, and recurrent hospital admissions. A major contributor to the pathophysiology and clinical presentation of heart failure is the activation of the renin-angiotensin-aldosterone system (RAAS). Normally, RAAS is responsible for the homeostatic regulation of blood pressure, extracellular fluid volume, and serum sodium concentration. In HFrEF, RAAS gets chronically activated in response to decreased cardiac output, further aggravating the congestion and cardiotoxic effects. Hence, inhibition of RAAS is a major approach in the pharmacologic treatment of those patients. The most recently introduced RAAS antagonizing medication class is angiotensin receptor blocker/ neprilysin inhibitor (ARNI). In this paper, we discuss ARNIs' superiority over traditional RAAS antagonizing agents in reducing heart failure hospitalization and mortality. We also tease out the evidence that shows ARNIs' renoprotective functions in heart failure patients including those with chronic or end stage kidney disease. We also discuss the evidence showing the added benefit resulting from combining ARNIs with a sodium-glucose cotransporter-2 (SGLT-2) inhibitor. Moreover, how ARNIs decrease the risk of arrhythmias and reverse cardiac remodeling, ultimately lowering the risk of cardiovascular death, is also discussed. We then present the positive outcome of ARNIs' use in patients with diabetes mellitus and those recovering from acute decompensated heart failure. ARNIs' side effects are also appreciated and discussed. Taken together, the provided insight and critical appraisal of the evidence justifies and supports the implementation of ARNIs in the guidelines for the treatment of HFrEF.

Fragment-based drug design of novel inhibitors targeting lipoprotein (a) kringle domain KIV-10-mediated cardiovascular disease

Cardiovascular diseases (CVDs) are the leading cause of death globally, attributed to a complex etiology involving metabolic, genetic, and protein-related factors. Lipoprotein(a) (Lp(a)), identified as a genetic risk factor, exhibits elevated levels linked to an increased risk of cardiovascular diseases. The lipoprotein(a) kringle domains have recently been identified as a potential target for the treatment of CVDs, in this study we utilized a fragment-based drug design approach to design a novel, potent, and safe inhibitor for lipoprotein(a) kringle domain. With the use of fragment library (61,600 fragments) screening, combined with analyses such as MM/GBSA, molecular dynamics simulation (MD), and principal component analysis, we successfully identified molecules effective against the kringle domains of Lipoprotein(a). The hybridization process (Breed) of the best fragments generated a novel 249 hybrid molecules, among them 77 exhibiting superior binding affinity (≤ -7 kcal/mol) compared to control AZ-02 (-6.9 kcal/mol), Importantly, the top ten molecules displayed high similarity to the control AZ-02. Among the top ten molecules, BR1 exhibited the best docking energy (-11.85 kcal/mol ), and higher stability within the protein LBS site, demonstrating the capability to counteract the pathophysiological effects of lipoprotein(a) [Lp(a)]. Additionally, principal component analysis (PCA) highlighted a similar trend of motion during the binding of BR1 and the control compound (AZ-02), limiting protein mobility and reducing conformational space. Moreover, ADMET analysis indicated favorable drug-like properties, with BR1 showing minimal violations of Lipinski's rules. Overall, the identified compounds hold promise as potential therapeutics, addressing a critical need in cardiovascular medicine. Further preclinical and clinical evaluations are needed to validate their efficacy and safety, potentially ushering in a new era of targeted therapies for CVDs.

Mitochondrial KATP channel-mediated autophagy contributes to angiotensin II-induced vascular dysfunction in mice

BACKGROUND AND AIM

The present study aimed to investigate whether the mitochondrial KATP channel contributes to angiotensin II (Ang II)-induced vascular dysfunction, the development of hypertension, and atherosclerosis.

METHODS AND RESULTS

ApoE (-/-) mice fed a high-fat diet were chronically infused with Ang II for eight weeks and concomitantly treated with losartan (ARB), apocynin, or 5-hydroxy decanoate (5-HD), or 3-methyladenine (3-MA). Systolic blood pressure was measured, and pathological changes of aortic or liver tissue were observed. Nitric oxide (NO), superoxide dismutase 2 (SOD2) levels and vasorelaxation rate were measured, and protein and mRNA expressions were examined by western blot and RT-PCR. Ang II-induced development of hypertension was suppressed not only by ARB, and apocynin but also by 5-HD or 3-MA. Ang II infusion decreased aortic NO production and relaxation, as well as SOD2 activity in liver, which were improved by all treatments. In addition, Ang II-induced activation of autophagy was suppressed by 5-HD in aortic tissue, furthermore, Ang II increases the atherosclerotic index in plasma and exacerbates the development of atherosclerosis by increases of fat deposition in the aorta and liver. Lipid metabolism-related mRNA expressions (LXR-α, LDLR, SRBI, Acca, and FASN) were changed by Ang II. Similarly, not only ARB, and apocynin, but also 5-HD and 3-MA suppressed Ang II-induced these changes.

CONCLUSIONS

Our present findings evidence that mitochondrial KATP channel-mediated autophagy contributes to Ang II-induced vascular dysfunction, development of hypertension, and atherosclerosis.

HIV-Associated Hypertension: Risks, Mechanisms, and Knowledge Gaps

HIV type 1 (HIV-1) is the causative agent of AIDS. Since the start of the epidemic, HIV/AIDS has been responsible for ≈40 million deaths. Additionally, an estimated 39 million people are currently infected with the virus. HIV-1 primarily infects immune cells, such as CD4+ (cluster of differentiation 4+) T lymphocytes (T cells), and as a consequence, the number of CD4+ T cells progressively declines in people living with HIV. Within a span of ≈10 years, HIV-1 infection leads to the systemic failure of the immune system and progression to AIDS. Fortunately, potent antiviral therapy effectively controls HIV-1 infection and prevents AIDS-related deaths. The efficacy of the current antiviral therapy regimens has transformed the outcome of HIV/AIDS from a death sentence to a chronic disease with a prolonged lifespan of people living with HIV. However, antiviral therapy is not curative, is challenged by virus resistance, can be toxic, and, most importantly, requires lifelong adherence. Furthermore, the improved lifespan has resulted in an increased incidence of non-AIDS-related morbidities in people living with HIV including cardiovascular diseases, renal disease, liver disease, bone disease, cancer, and neurological conditions. In this review, we summarize the current state of knowledge of the cardiovascular comorbidities associated with HIV-1 infection, with a particular focus on hypertension. We also discuss the potential mechanisms known to drive HIV-1-associated hypertension and the knowledge gaps in our understanding of this comorbid condition. Finally, we suggest several directions of future research to better understand the factors, pathways, and mechanisms underlying HIV-1-associated hypertension in the post-antiviral therapy era.

Nocturia and obstructive sleep apnoea

Nocturia, the need to urinate at night, is a common symptom in patients with obstructive sleep apnoea (OSA). Continuous positive airway pressure treatment can reduce nocturia in some patients, but the underlying mechanisms are complex and not fully understood. OSA affects the autonomic nervous system, oxidative stress and endothelial damage. Furthermore, the commonly held theory attributing polyuria to a false signal of cardiac overload and response natriuresis has limitations. A comprehensive approach to the management of nocturia in OSA, considering factors such as comorbidities, medication use, alcohol consumption and lifestyle, is needed. Effective management of nocturia in OSA requires a multidisciplinary approach, and urologists should be aware of the potential effect of OSA on physiology and refer patients for further testing at a sleep centre. In addition to continuous positive airway pressure, other interventions such as oral appliances and surgical obstruction treatment could be beneficial for some patients. Overall, understanding the complex interplay between OSA and nocturia is crucial for optimizing patient outcomes.

Assessment of Phthalate Esters and Physiological Biomarkers in Bottlenose Dolphins (Tursiops truncatus) and Killer Whales (Orcinus orca)

There is growing concern about the potential adverse health effects of phthalates (PAEs) on human health and the environment due to their extensive use as plasticizers and additives in commercial and consumer products. In this study, we assessed PAE concentrations in serum samples from aquarium-based delphinids (Tursiops truncatus, n = 36; Orcinus orca, n = 42) from California, Florida, and Texas, USA. To better understand the physiological effects of phthalates on delphinids, we also explored potential correlations between phthalates and the biomarkers aldosterone, cortisol, corticosterone, hydrogen peroxide, and malondialdehyde while accounting for sex, age, and reproductive stage. All PAEs were detected in at least one of the individuals. ΣPAE ranges were 5.995-2743 ng·mL-1 in bottlenose dolphins and 5.372-88,675 ng·mL-1 in killer whales. Both species displayed higher mean concentrations of DEP and DEHP. PAEs were detected in newborn delphinids, indicating transference via placenta and/or lactation. Linear mixed model results indicated significant correlations between aldosterone, month, location, status, and ΣPAEs in killer whales, suggesting that aldosterone concentrations are likely affected by the cumulative effects of these variables. This study expands on the knowledge of delphinid physiological responses to PAEs and may influence management and conservation decisions on contamination discharge regulations near these species.

Evaluation of blood pressure variation in recovered COVID-19 patients at one-year follow-up: a retrospective cohort study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has various sequelae, one of which might be hypertension. We aimed to evaluate COVID-19's impact on blood pressure (BP) in non-hospitalized patients at one-year follow-up.

METHOD

A total of 7,950 consecutive COVID-19 patients regularly visiting our cardiology clinic were retrospectively screened. Patients' electronic medical records including demographics, comorbidities, vital signs, treatments, and outcomes, were reviewed by two physicians. Individuals with at least one BP measurement in the three months preceding COVID-19 and one measurement in 12 months or more following recovery were included. BP levels before and after COVID-19 were compared using the paired t-test.

RESULTS

5,355 confirmed COVID-19 patients (mean age 55.51 ± 15.38 years) were included. Hypertension (56.9%) and diabetes mellitus (34%) were the predominant comorbidities, and 44.3% had prior major adverse cardiovascular events. Both systolic (126.90 ± 20.91 vs. 139.99 ± 23.94 mmHg, P < 0.001) and diastolic BP (80.54 ± 13.94 vs. 86.49 ± 14.40 mmHg, P < 0.001) were significantly higher post-COVID-19 vs. pre-COVID-19. Notably, 456 (14%) hypertensive patients experienced exacerbated hypertension, while 408 (17%) patients developed new-onset hypertension, overall 864 (16%) of patients had exacerbation or new hypertension. Linear regression analysis revealed that advanced age, smoking, previous cardiovascular events, hypertension, and diabetes mellitus predict increased BP following COVID-19 (P < 0.001).

CONCLUSION

COVID-19 raised systolic and diastolic BP in the long term in non-hospitalized patients, with over one-sixth developing new-onset or exacerbated hypertension. All patients should be evaluated regarding BP, following COVID-19 recovery, particularly those with the mentioned predictive factors. (clinicaltrial.gov: NCT05798208).

Predicting sex differences in the effects of diuretics in renal epithelial transport during angiotensin II-induced hypertension

Chronic angiotensin II (ANG II) infusion is an experimental model that induces hypertension in rodents. The natriuresis, diuresis, and blood pressure responses differ between males and females. This is perhaps not unexpected, given the rodent kidney, which plays a key role in blood pressure regulation, exhibits marked sex differences. Under normotensive conditions, compared with males, the female rat nephron exhibits lower Na+/H+ exchanger 3 (NHE3) activity along the proximal tubule but higher Na+ transporter activities along the distal segments. ANG II infusion-induced hypertension induces a pressure natriuretic response that reduces NHE3 activity and shifts Na+ transport capacity downstream. The goals of this study were to apply a computational model of epithelial transport along a rat nephron 1) to understand how a 14-day ANG II infusion impacts segmental electrolyte transport in male and female rat nephrons and 2) to identify and explain any sex differences in the effects of loop diuretics, thiazide diuretics, and K+-sparing diuretics. Model simulations suggest that the NHE3 downregulation in the proximal tubule is a major contributor to natriuresis and diuresis in hypertension, with the effects stronger in males. All three diuretics are predicted to induce stronger natriuretic and diuretic effects under hypertension compared with normotension, with relative increases in sodium excretion higher in hypertensive females than in males. The stronger natriuretic responses can be explained by the downstream shift of Na+ transport load in hypertension and by the larger distal transport load in females, both of which limit the ability of the distal segments to further elevate their Na+ transport.NEW & NOTEWORTHY Sex differences in the prevalence of hypertension are found in human and animal models. The kidney, which regulates blood pressure, exhibits sex differences in morphology, hemodynamics, and membrane transporter distributions. This computational modeling study provides insights into how the sexually dimorphic responses to a 14-day angiotensin II infusion differentially impact segmental electrolyte transport in rats. Simulations of diuretic administration explain how the natriuretic and diuretic effects differ between normotension and hypertension and between the sexes.

Genetic Appraisal of RAAS-Associated SNPs: REN (rs16853055), AGT (rs3789678) and ACE (rs4305) in Preeclamptic Women Living with HIV Infection

PURPOSE OF REVIEW

The primary goal of this review article was to determine whether the three RAAS-associated SNPs, Renin-rs16853055, AGT-rs3789678 and ACE-rs4305 are genetically linked to the development of hypertension in preeclampsia. The secondary goal was to establish if there was a link between these SNPs and HIV infection.

RECENT FINDINGS

There is a paucity of findings related to the aforementioned SNPs and preeclampsia. There are no recent findings on the rs16853055 renin polymorphism. The rs3789678 angiotensinogen polymorphism correlated significantly with gestational hypertension. The rs4305 ACE polymorphism showed no significant association with the development of pregnancy-induced hypertension. There are conflicting findings when determining the relationship between ethnicity and the predisposition of preeclampsia and hypertension in relation to the discussed RAAS-associated SNPs. To date, the association between RAAS-associated SNPs and preeclamptic women co-morbid with HIV in South Africa has revealed that certain alleles of the AGT gene are more prominent in HIV-infected PE compared to normotensive pregnant HIV-infected women.

Gustatory dysfunction and long COVID in Chinese patients with COVID-19: A 6-month follow-up study

AIMS

To evaluate long COVID of gustatory dysfunction and the associated risk factors regarding onset and recovery in Chinese patients.

METHODS

We conducted a cross-sectional study of patients with SARS-CoV-2 Omicron infection at Changxing Mobile Cabin Hospital in Shanghai, China, from March to May 2022. A prospective follow-up of patients with gustatory dysfunction was conducted at 6 months after discharge.

RESULTS

In total, 18.48% (241/1304) reported gustatory dysfunction. The 6-month follow-up response rate was 89.63% (216/241) and 74.02% recovered their taste sense within 1-3 weeks. A total of 20.37% of patients (44/216) presented with long COVID. Symptoms persisted for 12 patients (5.56%) after 6 months. Having multiple taste impairments (OR, 2.364; 95% CI, 1.286-4.348; p = 0.006) was associated with a higher risk of gustatory dysfunction with long COVID. Having received a COVID-19 vaccine booster was positively associated with taste sensation recovery (HR, 1.344; 95% CI, 1.012-1.785; p = 0.041).

CONCLUSIONS

About 20.37% of patients with COVID-19 might develop long COVID of gustatory dysfunction and 5.56% with persisting changes in their sense of taste. Most patients recovered taste sensations within 1-3 weeks after COVID-19 symptom onset and receiving a booster shot of the COVID-19 vaccine presented a protective effect on the taste sensation recovery.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

Sinapine targeting PLCβ3 EF hands disrupts Gαq-PLCβ3 interaction and ameliorates cardiovascular diseases

BACKGROUND

The renin-angiotensin-aldosterone system (RAAS) over-activation is highly involved in cardiovascular diseases (CVDs), with the Gαq-PLCβ3 axis acting as a core node of RAAS. PLCβ3 is a potential target of CVDs, and the lack of inhibitors has limited its drug development.

PURPOSE

Sinapine (SP) is a potential leading compound for treating CVDs. Thus, we aimed to elucidate the regulation of SP towards the Gαq-PLCβ3 axis and its molecular mechanism.

STUDY DESIGN

Aldosteronism and hypertension animal models were employed to investigate SP's inhibitory effect on the abnormal activation of the RAAS through the Gαq-PLCβ3 axis. We used chemical biology methods to identify potential targets and elucidate the underlying molecular mechanisms.

METHODS

The effects of SP on aldosteronism and hypertension were evaluated using an established animal model in our laboratory. Target identification and underlying molecular mechanism research were performed using activity-based protein profiling with a bio-orthogonal click chemistry reaction and other biochemical methods.

RESULTS

SP alleviated aldosteronism and hypertension in animal models by targeting PLCβ3. The underlying mechanism for blocking the Gαq-PLCβ3 interaction involves targeting the EF hands through the Asn-260 amino acid residue. SP regulated the Gαq-PLCβ3 axis more precisely than the Gαq-GEFT or Gαq-PKCζ axis in the cardiovascular system.

CONCLUSION

SP alleviated RAAS over-activation via Gαq-PLCβ3 interaction blockade by targeting the PLCβ3 EF hands domain, which provided a novel PLC inhibitor for treating CVDs. Unlike selective Gαq inhibitors, SP reduced the risk of side effects compared to Gαq inhibitors in treating CVDs.

The role of angiotensin receptor blockers in treating epilepsy: a review

Epilepsy is a chronic brain disease with a global prevalence of 70 million people. According to the World Health Organization, roughly 5 million new cases are diagnosed every year. Anti-seizure drugs are the treatment of choice. However, in roughly one third of the patients, these drugs fail to produce the desired effect. As a result, finding novel treatments for epilepsy becomes inevitable. Recently, angiotensin receptor blockers have been proposed as a treatment to reduce the over-excitation of neurons in epilepsy. For this purpose, we conducted a review using Medline/PubMed and Google Scholar using the relevant search terms and extracted the relevant data in a table. Our review suggests that this novel approach has a very high potential to treat epilepsy, especially in those patients who fail to respond to conventional treatment options. However, more extensive and human-based trials should be conducted to reach a decisive conclusion. Nevertheless, the use of ARBs in patients with epilepsy should be carefully monitored keeping the adverse effects in mind.

Quercetin prophylaxis protects the kidneys by modulating the renin-angiotensin-aldosterone axis under acute hypobaric hypoxic stress

The study presented here aims at assessing the effects of hypobaric hypoxia on RAAS pathway and its components along with mitigation of anomalies with quercetin prophylaxis. One hour prior to hypobaric hypoxia exposure, male SD rats were orally supplemented with quercetin (50 mg/kg BW) and acetazolamide (50 mg/kg BW) and exposed them to 25,000 ft. (7,620 m) in a simulated environmental chamber for 12 h at 25 ± 2 °C. Different biochemical parameters like renin activity, aldosterone, angiotensin I, ACE 2 were determined in plasma. As a conventional response to low oxygen conditions, oxidative stress parameters (ROS and MDA) were elevated along with suppressed antioxidant system (GPx and catalase) in plasma of rats. Quercetin prophylaxis significantly down regulated the hypoxia induced oxidative stress by reducing plasma ROS & MDA levels with efficient enhancement of antioxidants (GPx and Catalase). Further, hypoxia mediated regulation of renin and ACE 2 proves the outstanding efficacy of quercetin in repudiating altercations in RAAS cascade due to hypobaric hypoxia. Furthermore, differential protein expression of HIF-1α, NFκB, IL-18 and endothelin-1 analyzed by western blotting approves the biochemical outcomes and showed that quercetin significantly aids in the reduction of inflammation under hypoxia. Studies conducted with Surface Plasmon Resonance demonstrated a binding among quercetin and ACE 2 that indicates that this flavonoid might regulate RAAS pathway via ACE 2. Henceforth, the study promotes the prophylaxis of quercetin for the better adaptability under hypobaric hypoxic conditions via modulating the RAAS pathway.

Untargeted metabolomics uncovers metabolic dysregulation and tissue sensitivity in ACE2 knockout mice

Angiotensin-converting enzyme 2 (ACE2) polymorphisms are associated with increased risk of type 2 diabetes mellitus (T2DM), obesity and dyslipidemia, which have been determined in various populations. Consistently, ACE2 knockout (ACE2 KO) mice display damaged energy metabolism in multiple tissues, especially the key metabolic tissues such as liver, skeletal muscle and epididymal white adipose tissue (eWAT) and show even more severe phenotype under high-fat diet (HFD) induced metabolic stress. However, the effects of ACE2 on global metabolomics profiling and the tissue sensitivity remain unclear. To understand how tissues independently and collectively respond to ACE2, we performed untargeted metabolomics in serum in ACE2 KO and control wild type (WT) mice both on normal diet (ND) and HFD, and in three key metabolic tissues (liver, skeletal muscle and eWAT) after HFD treatment. The results showed significant alterations in metabolic profiling in ACE2 KO mice. We identified 275 and 168 serum metabolites differing significantly between WT and ACE2 KO mice fed on ND and HFD, respectively. And the altered metabolites in the ACE2 KO group varied from 90 to 196 in liver, muscle and eWAT. The alterations in ND and HFD serum were most similar. Compared with WT mice, ACE2 KO mice showed an increase in N-phenylacetylglutamine (PAGln), methyl indole-3-acetate, 5-hydroxytryptophol, cholic acid, deoxycholic acid and 12(S)-HETE, while LPC (19:0) and LPE (16:1) decreased. Moreover, LPC (20:0), LPC (20:1) and PC (14:0e/6:0) were reduced in both ND and HFD serum, paralleling the decreases identified in HFD skeletal muscle. Interestingly, DL-tryptophan, indole and Gly-Phe decreased in both ND and HFD serum but were elevated in HFD liver of ACE2 KO mice. A low level of l-ergothioneine was observed among liver, muscle, and epididymal fat tissue of ACE2 KO mice. Pathway analysis demonstrated that different tissues exhibited different dysregulated metabolic pathways. In conclusion, these results revealed that ACE2 deficiency leads to an overall state of metabolic distress, which may provide a new insight into the underlying pathogenesis in metabolic disorders in both ACE2 KO mice and in patients with certain genetic variant of ACE2 gene.

ACE2 and TMPRSS2 expression in patients before, during, and after SARS-CoV-2 infection

During the SARS-CoV-2 pandemic angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) were constantly under the scientific spotlight, but most studies evaluated ACE2 and TMPRSS2 expression levels in patients infected by SARS-CoV-2. Thus, this study aimed to evaluate the expression levels of both proteins before, during, and after-infection. For that, nasopharyngeal samples from 26 patients were used to measure ACE2/TMPRSS2 ex-pression via qPCR. Symptomatic patients presented lower ACE2 expression levels before and after the infection than those in asymptomatic patients; however, these levels increased during SARS-CoV-2 infection. In addition, symptomatic patients presented higher expression levels of TMPRSS2 pre-infection, which decreased in the following periods. In summary, ACE2 and TMPRSS2 expression levels are potential risk factors for the development of symptomatic COVID-19, and the presence of SARS-CoV-2 potentially modulates those levels.

Exercise in Diabetic Nephropathy: Protective Effects and Molecular Mechanism

Diabetic nephropathy (DN) is a serious complication of diabetes, and its progression is influenced by factors like oxidative stress, inflammation, cell death, and fibrosis. Compared to drug treatment, exercise offers a cost-effective and low-risk approach to slowing down DN progression. Through multiple ways and mechanisms, exercise helps to control blood sugar and blood pressure and reduce serum creatinine and albuminuria, thereby alleviating kidney damage. This review explores the beneficial effects of exercise on DN improvement and highlights its potential mechanisms for ameliorating DN. In-depth understanding of the role and mechanism of exercise in improving DN would pave the way for formulating safe and effective exercise programs for the treatment and prevention of DN.

The recent advance and prospect of natural source compounds for the treatment of heart failure

Heart failure is a continuously developing syndrome of cardiac insufficiency caused by diseases, which becomes a major disease endangering human health as well as one of the main causes of death in patients with cardiovascular diseases. The occurrence of heart failure is related to hemodynamic abnormalities, neuroendocrine hormones, myocardial damage, myocardial remodeling etc, lead to the clinical manifestations including dyspnea, fatigue and fluid retention with complex pathophysiological mechanisms. Currently available drugs such as cardiac glycoside, diuretic, angiotensin-converting enzyme inhibitor, vasodilator and β receptor blocker etc are widely used for the treatment of heart failure. In particular, natural products and related active ingredients have the characteristics of mild efficacy, low toxicity, multi-target comprehensive efficacy, and have obvious advantages in restoring cardiac function, reducing energy disorder and improving quality of life. In this review, we mainly focus on the recent advance including mechanisms and active ingredients of natural products for the treatment of heart failure, which will provide the inspiration for the development of more potent clinical drugs against heart failure.

Glucose transport, transporters and metabolism in diabetic retinopathy

Diabetic retinopathy (DR) is the most common reason for blindness in working-age individuals globally. Prolonged high blood glucose is a main causative factor for DR development, and glucose transport is prerequisite for the disturbances in DR caused by hyperglycemia. Glucose transport is mediated by its transporters, including the facilitated transporters (glucose transporter, GLUTs), the "active" glucose transporters (sodium-dependent glucose transporters, SGLTs), and the SLC50 family of uniporters (sugars will eventually be exported transporters, SWEETs). Glucose transport across the blood-retinal barrier (BRB) is crucial for nourishing the neuronal retina in the context of retinal physiology. This physiological process primarily relies on GLUTs and SGLTs, which mediate the glucose transportation across both the cell membrane of retinal capillary endothelial cells and the retinal pigment epithelium (RPE). Under diabetic conditions, increased accumulation of extracellular glucose enhances the retinal cellular glucose uptake and metabolism via both glycolysis and glycolytic side branches, which activates several biochemical pathways, including the protein kinase C (PKC), advanced glycation end-products (AGEs), polyol pathway and hexosamine biosynthetic pathway (HBP). These activated biochemical pathways further increase the production of reactive oxygen species (ROS), leading to oxidative stress and activation of Poly (ADP-ribose) polymerase (PARP). The activated PARP further affects all the cellular components in the retina, and finally resulting in microangiopathy, neurodegeneration and low-to-moderate grade inflammation in DR. This review aims to discuss the changes of glucose transport, glucose transporters, as well as its metabolism in DR, which influences the retinal neurovascular unit (NVU) and implies the possible therapeutic strategies for treating DR.

The pharmaco-epigenetics of hypertension: a focus on microRNA

Hypertension is a major harbinger of cardiovascular morbidity and mortality. It predisposes to higher rates of myocardial infarction, chronic kidney failure, stroke, and heart failure than most other risk factors. By 2025, the prevalence of hypertension is projected to reach 1.5 billion people. The pathophysiology of this disease is multifaceted, as it involves nitric oxide and endothelin dysregulation, reactive oxygen species, vascular smooth muscle proliferation, and vessel wall calcification, among others. With the advent of new biomolecular techniques, various studies have elucidated a gaping hole in the etiology and mechanisms of hypertension. Indeed, epigenetics, DNA methylation, histone modification, and microRNA-mediated translational silencing appear to play crucial roles in altering the molecular phenotype into a hypertensive profile. Here, we critically review the experimentally determined associations between microRNA (miRNA) molecules and hypertension pharmacotherapy. Particular attention is given to the epigenetic mechanisms underlying the physiological responses to antihypertensive drugs like candesartan, and other relevant drugs like clopidogrel, aspirin, and statins among others. Furthermore, how miRNA affects the pharmaco-epigenetics of hypertension is especially highlighted.

Parallelism and non-parallelism in diabetic nephropathy and diabetic retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR), as microvascular complications of diabetes mellitus, are currently the leading causes of end-stage renal disease (ESRD) and blindness, respectively, in the adult working population, and they are major public health problems with social and economic burdens. The parallelism between the two in the process of occurrence and development manifests in the high overlap of disease-causing risk factors and pathogenesis, high rates of comorbidity, mutually predictive effects, and partial concordance in the clinical use of medications. However, since the two organs, the eye and the kidney, have their unique internal environment and physiological processes, each with specific influencing molecules, and the target organs have non-parallelism due to different pathological changes and responses to various influencing factors, this article provides an overview of the parallelism and non-parallelism between DN and DR to further recognize the commonalities and differences between the two diseases and provide references for early diagnosis, clinical guidance on the use of medication, and the development of new drugs.

Myeloid ACE2 protects against septic hypotension and vascular dysfunction through Ang-(1-7)-Mas-mediated macrophage polarization

Angiotensin converting enzyme 2 (ACE2) is a new identified member of the renin-angiotensin-aldosterone system (RAAS) that cleaves angiotensin II (Ang II) to Ang (1-7), which exerts anti-inflammatory and antioxidative activities via binding with Mas receptor (MasR). However, the functional role of ACE2 in sepsis-related hypotension remains unknown. Our results indicated that sepsis significantly reduced blood pressure and led to disruption between ACE-Ang II and ACE2-Ang (1-7) balance. ACE2 knock-in mice exhibited improved sepsis-induced mortality, hypotension and vascular dysfunction, while ACE2 knockout mice exhibited the opposite effects. Bone marrow transplantation and in vitro experiments confirmed that myeloid ACE2 exerted a protective role by suppressing oxidative stress, NO production and macrophage polarization via the Ang (1-7)-MasR-NF-κB and STAT1 pathways. Thus, ACE2 on myeloid cells could protect against sepsis-mediated hypotension and vascular dysfunction, and upregulating ACE2 may represent a promising therapeutic option for septic patients with hypotension.

Hypothyroidism and subclinical hypothyroidism are associated with fatty pancreas (Non-Alcoholic Fatty Pancreas Disease)

OBJECTIVES

Increasing visceral fat deposition with raised prevalence of obesity and metabolic syndrome is associated with many adverse conditions, especially cardiovascular diseases and diabetes. Although there are many studies that investigate hepatic steatosis in hypothyroidism and subclinical hypothyroidism, to the best of our knowledge, there is no study investigating its relationship with pancreatic steatosis. In the present study, the purpose was to investigate this relationship.

METHODS

Physical and biochemical characteristics of 30 hypothyroid, 30 subclinical hypothyroid, and 30 euthyroid volunteers were recorded in this cross-sectional study. Liver and pancreatic steatosis were evaluated with ultrasonography.

RESULTS

It was found that pancreatic steatosis was increased in hypothyroid and subclinical groups when compared to the control group, and hepatic steatosis was increased in the subclinical group when compared to the control group (steatosis; p = 0.002, p = 0.004, p = 0.001, p = 0.002, p = 0.002, p = 0.004). Pancreatic steatosis was positively correlated with age, hepatic steatosis, height, weight, BMI, waist circumference, hip circumference, hemoglobin, Insulin, alanine aminotransferase, Triglyceride, Creatinine, and gamma-glutamyltransferase and was negatively correlated with total cholesterol, high-density lipoproteins.

CONCLUSIONS

The prevalence of pancreatic steatosis was found to be increased in hypothyroidism and subclinical hypothyroidism when compared with the euthyroid control group.

Effect of exercise training on the renin-angiotensin-aldosterone system: a meta-analysis

Blood pressure (BP) management reduces the risk of cardiovascular disease (CVD). The renin-angiotensin-aldosterone system (RAAS) plays an important role in regulating and maintaining blood volume and pressure. This analysis aimed to investigate the effect of exercise training on plasma renin, angiotensin-II and aldosterone, epinephrine, norepinephrine, urinary sodium and potassium, BP and heart rate (HR). We systematically searched PubMed, Web of Science, and the Cochrane Library of Controlled Trials until 30 November 2022. The search strategy included RAAS key words in combination with exercise training terms and medical subject headings. Manual searching of reference lists from systematic reviews and eligible studies completed the search. A random effects meta-analysis model was used. Eighteen trials with a total of 803 participants were included. After exercise training, plasma angiotensin-II (SMD -0.71; 95% CI -1.24, -0.19; p = 0.008; n = 9 trials), aldosterone (SMD -0.37; 95% CI -0.65, -0.09; p = 0.009; n = 8 trials) and norepinephrine (SMD -0.82; 95% CI -1.18, -0.46; p < 0.001; n = 8 trials) were reduced. However, plasma renin activity, epinephrine, and 24-h urinary sodium and potassium excretion remained unchanged with exercise training. Systolic BP was reduced (MD -6.2 mmHg; 95% CI -9.9, -2.6; p = 0.001) as was diastolic BP (MD -4.5 mmHg; 95% CI -6.9, -2.1; p < 0.001) but not HR (MD -3.0 bpm; 95% CI -6.0, 0.4; p = 0.053). Exercise training may reduce some aspects of RAAS and sympathetic nervous system activity, and this explains some of the anti-hypertensive response.

Network pharmacology combined with Mendelian randomization analysis to identify the key targets of renin-angiotensin-aldosterone system inhibitors in the treatment of diabetic nephropathy

Background

Diabetic Nephropathy (DN) is one of the microvascular complications of diabetes. The potential targets of renin-angiotensin-aldosterone system (RAAS) inhibitors for the treatment of DN need to be explored.

Methods

The GSE96804 and GSE1009 datasets, 729 RAAS inhibitors-related targets and 6,039 DN-related genes were derived from the public database and overlapped with the differentially expressed genes (DN vs. normal) in GSE96804 to obtain the candidate targets. Next, key targets were screened via the Mendelian randomization analysis and expression analysis. The diagnostic nomogram was constructed and assessed in GSE96804. Additionally, enrichment analysis was conducted and a 'core active ingredient-key target-disease pathway' network was established. Finally, molecular docking was performed.

Results

In total, 60 candidate targets were derived, in which CTSC and PDE5A were screened as the key targets and had a causal association with DN as the protective factors (P < 0.05, OR < 1). Further, a nomogram exhibited pretty prediction efficiency. It is indicated that Benadryl hydrochloride might play a role in the DN by affecting the pathways of 'cytokine cytokine receptor interaction', etc. targeting the CTSC. Moreover, PDE5A might be involved in 'ECM receptor interaction', etc. for the effect of NSAID, captopril, chlordiazepoxide on DN. Molecular docking analysis showed a good binding ability of benadryl hydrochloride and CTSC, NSAID and PDE5A. PTGS2, ITGA4, and ANPEP are causally associated with acute kidney injury.

Conclusion

CTSC and PDE5A were identified as key targets for RAAS inhibitors in the treatment of DN, which might provide some clinical significance in helping to diagnose and treat DN. Among the targets of RAAS inhibitors, PTGS2, ITGA4 and ANPEP have a causal relationship with acute kidney injury, which is worthy of further clinical research.

ACE I/D polymorphism is a risk factor for the clinical severity of COVID-19 in Brazilian male patients

BACKGROUND

The renin-angiotensin system is potentially involved in the pathogen-host interaction in the disease caused by SARS-CoV-2, since the angiotensin-converting enzyme (ACE) 2 serves as a receptor for the virus. The impact of the pandemic in specific regions and ethnic groups highlights the importance of investigating genetic factors that disrupt the balance of the system in response to SARS-CoV-2 infection, especially in genes with ethnic frequency variations. Therefore, this study aimed to evaluate the influence of the ACE I/D polymorphism on the incidence and severity of COVID-19 in a sample of the Brazilian population.

METHODS AND RESULTS

70 severe cases and 355 mild cases patients were evaluated. DNA extraction was performed using a QIAamp DNA Blood Mini kit. Genotyping of ACE I/D polymorphism was performed. Clinical outcomes were obtained from the patients' records. We found an association between the ACE I/D polymorphism and the incidence or severity of COVID-19 in male participants. Moreover, we observed a relationship between severity and increasing age and body weight and a higher frequency of II genotype individuals among those who had a cough as their symptoms in mild patients. No differences were observed in leukocyte count or other parameters related to the inflammatory response in severe patients.

CONCLUSIONS

Our data showed the influence of the ACE I/D polymorphism on severity of COVID-19 in males, as well as on the occurrence of cough in patients with mild symptoms, with a higher incidence in those carrying the I allele.

Paediatric perspectives in the diagnosis of polyuria-polydipsia syndrome

The elucidation of the underlying cause of polyuria-polydipsia syndrome (PPS) is a challenging-especially in the differentiation of partial defects of arginine vasopressin (AVP) secretion or action from primary polydipsia. The water deprivation test has been utilized for many decades, and its application in the paediatric population has been applied using parameters predominantly established in adult cohorts. In more recent times, the development of automated commercial assays for copeptin, a surrogate marker for AVP, has represented a significant advancement in the diagnostic approach to PPS. Measurement of copeptin concentrations has major advantages and has essentially superseded measurement of AVP in diagnostic protocols for PPS. Additionally, stimulated-copeptin protocols utilizing hypertonic saline infusion, arginine, and glucagon have been investigated, and are promising. However, further studies are required in the population-incorporating the differences in physiological regulation of water homeostasis, and safety requirements-before there is widespread adoption into clinical practice.

Prior Use of Angiotensin-converting Enzyme Inhibitors or Angiotensin II Receptor Blockers and Clinical Outcomes of Sepsis and Septic Shock: A Systematic Review and Meta-analysis

ABSTRACT

Sepsis and septic shock are life-threatening conditions that are associated with high mortality and considerable health care costs. The association between prior angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARBs) use and outcomes after sepsis is elusive. The aim of this study was to evaluate the role of the prior use of ACEi or ARBs and outcomes after sepsis and septic shock. A relevant literature review was performed in 4 databases from inception until July 2022. Independent reviewers first screened the title, abstract, and full text, and then, data extraction and analysis were performed. One post hoc analysis of a trial and 6 retrospective cohort studies were included in this review. There were 22% lower odds of in-hospital/30-day mortality among patients who have used ACEi/ARBs in the past [23.83% vs. 37.20%; odds ratio (OR), 0.78, 95% confidence interval (CI), 0.64-0.96], and reduced 90-day mortality (OR, 0.80, 95% CI, 0.69-0.92). ACEi/ARBs users were found to have 31% lesser odds of developing acute kidney injury as compared with nonusers (OR, 0.69, 95% CI, 0.63-0.76). There was no significant difference in the length of hospital stay (MD 1.26, 95% CI, ‒7.89 to 10.42), need for renal replacement therapy (OR, 0.71, 95% CI, 0.13-3.92), mechanical ventilation (OR, 1.10, 95% CI, 0.88-1.37) or use of vasopressors (OR, 1.21, 95% CI, 0.91-1.61). Based on this analysis, prior use of ACEi/ARBs lowers the risk of mortality and adverse renal events in patients with sepsis and septic shock.

The ACE2/Ang-(1-7)/MasR axis alleviates brain injury after cardiopulmonary resuscitation in rabbits by activating PI3K/Akt signaling

Background

Death among resuscitated patients is mainly caused by brain injury after cardiac arrest/cardiopulmonary resuscitation (CA/CPR). The angiotensin converting enzyme 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor (MasR) axis has beneficial effects on brain injury. Therefore, we examined the roles of the ACE2/Ang-(1-7)/MasR axis in brain injury after CA/CPR.

Method

We used a total of 76 male New Zealand rabbits, among which 10 rabbits underwent sham operation and 66 rabbits received CA/CPR. Neurological functions were determined by assessing serum levels of neuron-specific enolase and S100 calcium-binding protein B and neurological deficit scores. Brain water content was estimated. Neuronal apoptosis in the hippocampus was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling assays. The expression levels of various genes were measured by enzyme-linked immunosorbent assay and western blotting.

Results

Ang-(1-7) (MasR activator) alleviated CA/CPR-induced neurological deficits, brain edema, and neuronal damage, and A779 (MasR antagonist) had the opposite functions. The stimulation of ACE2/Ang-(1-7)/MasR inactivated the ACE/Ang II/AT1R axis and activated PI3K/Akt signaling. Inhibiting PI3K/Akt signaling inhibited Ang-(1-7)-mediated protection against brain damage after CA/CPR.

Conclusion

Collectively, the ACE2/Ang-(1-7)/MasR axis alleviates CA/CPR-induced brain injury through attenuating hippocampal neuronal apoptosis by activating PI3K/Akt signaling.

Soyasaponin I alleviates hypertensive intracerebral hemorrhage by inhibiting the renin-angiotensin-aldosterone system

BACKGROUND

Hypertensive intracerebral hemorrhage (HICH) is a life-threatening disease and lacks effective treatments. Previous studies have confirmed that metabolic profiles altered after ischemic stroke, but how brain metabolism changes after HICH was unclear. This study aimed to explore the metabolic profiles after HICH and the therapeutic effects of soyasaponin I on HICH.

METHODS

HICH model was established first. Hematoxylin and eosin staining was used to estimate the pathological changes after HICH. Western blot and Evans blue extravasation assay were applied to determine the integrity of the blood-brain barrier (BBB). Enzyme-linked immunosorbent assay was used to detect the activation of the renin-angiotensin-aldosterone system (RAAS). Next, liquid chromatography-mass spectrometry-untargeted metabolomics was utilized to analyze the metabolic profiles of brain tissues after HICH. Finally, soyasaponin I was administered to HICH rats, and the severity of HICH and activation of the RAAS were further assessed.

RESULTS

We successfully constructed HICH model. HICH significantly impaired BBB integrity and activated RAAS. HICH increased PE(14:0/24:1(15Z)), arachidonoyl serinol, PS(18:0/22:6(4Z, 7Z, 10Z, 13Z, 16Z, and 19Z)), PS(20:1(11Z)/20:5(5Z, 8Z, 11Z, 14Z, and 17Z)), glucose 1-phosphate, etc., in the brain, whereas decreased creatine, tripamide, D-N-(carboxyacetyl)alanine, N-acetylaspartate, N-acetylaspartylglutamic acid, and so on in the hemorrhagic hemisphere. Cerebral soyasaponin I was found to be downregulated after HICH and supplementation of soyasaponin I inactivated the RAAS and alleviated HICH.

CONCLUSION

The metabolic profiles of the brains changed after HICH. Soyasaponin I alleviated HICH via inhibiting the RAAS and may serve as an effective drug for the treatment of HICH in the future.

An emerging view on vascular fibrosis molecular mediators and relevant disorders: from bench to bed

Vascular fibrosis is a widespread pathologic condition that arises during vascular remodeling in cardiovascular dysfunctions. According to previous studies, vascular fibrosis is characterized by endothelial matrix deposition and vascular wall thickening. The RAAS and TGF-β/Smad signaling pathways have been frequently highlighted. It is, however, far from explicit in terms of understanding the cause and progression of vascular fibrosis. In this review, we collected and categorized a large number of molecules which influence the fibrosing process, in order to acquire a better understanding of vascular fibrosis, particularly of pathologic dysfunction. Furthermore, several mediators that prevent vascular fibrosis are discussed in depth in this review, with the aim that this will contribute to the future prevention and treatment of related conditions.

Rare case of steroid cell tumour presenting as resistant hypertension in early pregnancy

A woman 12 weeks and 3 days pregnant was referred to the emergency department with significant hypertension which, despite aggressive medical management, remained uncontrolled. Markedly elevated levels of renin and aldosterone beyond what is typical in early pregnancy were present, which together with the finding of a right ovarian cyst pointed to the possible diagnosis of an extrarenal reninoma.and the decision was made to perform a right-sided oophorectomy at 16 weeks gestation. Histology demonstrated a staining pattern most consistent with a steroid cell tumour leading to the diagnosis of refractory hypertension secondary to an ovarian steroid cell tumour. Post oophorectomy blood biochemistry rapidly returned to normal, and our patient's hypertension slowly resolved allowing for a large reduction in antihypertensive agent requirements and a successful pregnancy outcome.

The SLC6A15-SLC6A20 Neutral Amino Acid Transporter Subfamily: Functions, Diseases, and Their Therapeutic Relevance

The neutral amino acid transporter subfamily that consists of six members, consecutively SLC6A15-SLC620, also called orphan transporters, represents membrane, sodium-dependent symporter proteins that belong to the family of solute carrier 6 (SLC6). Primarily, they mediate the transport of neutral amino acids from the extracellular milieu toward cell or storage vesicles utilizing an electric membrane potential as the driving force. Orphan transporters are widely distributed throughout the body, covering many systems; for instance, the central nervous, renal, or intestinal system, supplying cells into molecules used in biochemical, signaling, and building pathways afterward. They are responsible for intestinal absorption and renal reabsorption of amino acids. In the central nervous system, orphan transporters constitute a significant medium for the provision of neurotransmitter precursors. Diseases related with aforementioned transporters highlight their significance; SLC6A19 mutations are associated with metabolic Hartnup disorder, whereas altered expression of SLC6A15 has been associated with a depression/stress-related disorders. Mutations of SLC6A18-SLCA20 cause iminoglycinuria and/or hyperglycinuria. SLC6A18-SLC6A20 to reach the cellular membrane require an ancillary unit ACE2 that is a molecular target for the spike protein of the SARS-CoV-2 virus. SLC6A19 has been proposed as a molecular target for the treatment of metabolic disorders resembling gastric surgery bypass. Inhibition of SLC6A15 appears to have a promising outcome in the treatment of psychiatric disorders. SLC6A19 and SLC6A20 have been suggested as potential targets in the treatment of COVID-19. In this review, we gathered recent advances on orphan transporters, their structure, functions, related disorders, and diseases, and in particular their relevance as therapeutic targets. SIGNIFICANCE STATEMENT: The following review systematizes current knowledge about the SLC6A15-SLCA20 neutral amino acid transporter subfamily and their therapeutic relevance in the treatment of different diseases.

Clinical findings, underlying pathogenetic processes and treatment of vascular dysfunction in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the development of fluid-filled cysts in the kidneys. The primary cause of ADPKD is mutations in the PKD1 (polycystic kidney disease 1) or PKD2 (polycystic kidney disease 2) gene. Patients with ADPKD often develop a variety of vascular abnormalities, which have a major impact on the structure and function of the blood vessels and can lead to complications such as hypertension, intracranial aneurysm (ICAN), and atherosclerosis. The progression of ADPKD involves intricate molecular and cellular processes that lead to the development of these vascular abnormalities. Our understanding of these processes remains incomplete, and available treatment options are limited. The aim of this review is to delve into the underlying mechanisms of these vascular abnormalities and to explore potential interventions.

From cardiovascular system to brain, the potential protective role of Mas Receptors in COVID-19 infection

Coronavirus disease 2019 (COVID-19) has been declared a new pandemic in March 2020. Although most patients are asymptomatic, those with underlying cardiovascular comorbidities may develop a more severe systemic infection which is often associated with fatal pneumonia. Nonetheless, neurological and cardiovascular manifestations could be present even without respiratory symptoms. To date, no COVID-19-specific drugs are able for preventing or treating the infection and generally, the symptoms are relieved with general anti-inflammatory drugs. Angiotensin-converting-enzyme 2 (ACE2) may function as the receptor for virus entry within the cells favoring the progression of infection in the organism. On the other hand, ACE2 is a relevant enzyme in renin angiotensin system (RAS) cascade fostering Ang1-7/Mas receptor activation which promotes protective effects in neurological and cardiovascular systems. It is known that RAS is composed by two functional countervailing axes the ACE/AngII/AT1 receptor and the ACE/AngII/AT2 receptor which counteracts the actions mediated by AngII/AT1 receptor by inducing anti-inflammatory, antioxidant and anti-growth functions. Subsequently an "alternative" ACE2/Ang1-7/Mas receptor axis has been described with functions similar to the latter protective arm. Here, we discuss the neurological and cardiovascular effects of COVID-19 highlighting the role of the stimulation of the RAS "alternative" protective arm in attenuating pulmonary, cerebral and cardiovascular damages. In conclusion, only two clinical trials are running for Mas receptor agonists but few other molecules are in preclinical phase and if successful these drugs might represent a successful strategy for the treatment of the acute phase of COVID-19 infection.