Antibodies against Angiotensin II Type 1 and Endothelin 1 Type A Receptors in Cardiovascular Pathologies

Angiotensin II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) are G-protein-coupled receptors (GPCRs) expressed on the surface of a great variety of cells: immune cells, vascular smooth cells, endothelial cells, and fibroblasts express ETAR and AT1R, which are activated by endothelin 1 (ET1) and angiotensin II (AngII), respectively. Certain autoantibodies are specific for these receptors and can regulate their function, thus being known as functional autoantibodies. The function of these antibodies is similar to that of natural ligands, and it involves not only vasoconstriction, but also the secretion of proinflammatory cytokines (such as interleukin-6 (IL6), IL8 and TNF-α), collagen production by fibroblasts, and reactive oxygen species (ROS) release by fibroblasts and neutrophils. The role of autoantibodies against AT1R and ETAR (AT1R-AAs and ETAR-AAs, respectively) is well described in the pathogenesis of many medical conditions (e.g., systemic sclerosis (SSc) and SSc-associated pulmonary hypertension, cystic fibrosis, and allograft dysfunction), but their implications in cardiovascular diseases are still unclear. This review summarizes the current evidence regarding the effects of AT1R-AAs and ETAR-AAs in cardiovascular pathologies, highlighting their roles in heart transplantation and mechanical circulatory support, preeclampsia, and acute coronary syndromes.

Effects of Antihypertensive Drugs Use on Risk and Prognosis of Colorectal Cancer: A Meta-Analysis of 37 Observational Studies

Background: Antihypertensive drugs might play a key role in the risk and poor prognosis of colorectal cancer. However, current epidemiologic evidence remains inconsistent. The aim of this study is to quantify the association between antihypertensive drugs and colorectal cancer.Methods: To identify available studies, we systematically searched electronic databases: PubMed, Web of Science, Embase, Cochrane Library. The risk estimates and their corresponding 95% confidence intervals (CIs) were collected and analyzed by using random-effects models. Heterogeneity test and sensitivity analysis were also performed.Results: Overall, 37 observational studies were included in this analysis (26 studies with cohort design, three studies with nested case-control design, and 8 studies with case-control design). Antihypertensive drugs did not present a significant effect on the risk or overall survival of patients with colorectal cancer [Risk ratio (RR) = 1.00, 95% CI: 0.95–1.04; Hazard ratio (HR) = 0.93, 95% CI: 0.84–1.02]. In the subgroup analysis, diuretics use was significantly associated with a worse overall survival of patients with colorectal cancer (HR = 1.27; 95% CI: 1.14–1.40). However, use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was associated with improved progression-free survival of patients who suffered from colorectal cancer (HR = 0.83; 95% CI: 0.72–0.95).Conclusion: Antihypertensive drug usage did not influence the risk and overall survival of patients with colorectal cancer in general. Further investigation reminded us that diuretics use might reduce the overall survival time in colorectal cancer patients, whereas those who took Angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers had a longer progression-free survival.

Mortality and Severity in COVID-19 Patients on ACEIs and ARBs—A Systematic Review, Meta-Analysis, and Meta-Regression Analysis

Purpose: The primary objective of this systematic review is to assess association of mortality in COVID-19 patients on Angiotensin-converting-enzyme inhibitors (ACEIs) and Angiotensin-II receptor blockers (ARBs). A secondary objective is to assess associations with higher severity of the disease in COVID-19 patients.Materials and Methods: We searched multiple COVID-19 databases (WHO, CDC, LIT-COVID) for longitudinal studies globally reporting mortality and severity published before January 18th, 2021. Meta-analyses were performed using 53 studies for mortality outcome and 43 for the severity outcome. Mantel-Haenszel odds ratios were generated to describe overall effect size using random effect models. To account for between study results variations, multivariate meta-regression was performed with preselected covariates using maximum likelihood method for both the mortality and severity models.Result: Our findings showed that the use of ACEIs/ARBs did not significantly influence either mortality (OR = 1.16 95% CI 0.94–1.44, p = 0.15, I2 = 93.2%) or severity (OR = 1.18, 95% CI 0.94–1.48, p = 0.15, I2 = 91.1%) in comparison to not being on ACEIs/ARBs in COVID-19 positive patients. Multivariate meta-regression for the mortality model demonstrated that 36% of between study variations could be explained by differences in age, gender, and proportion of heart diseases in the study samples. Multivariate meta-regression for the severity model demonstrated that 8% of between study variations could be explained by differences in age, proportion of diabetes, heart disease and study country in the study samples.Conclusion: We found no association of mortality or severity in COVID-19 patients taking ACEIs/ARBs.

Changes in Glycated Human Serum Albumin Binding Affinity for Losartan in the Presence of Fatty Acids In Vitro Spectroscopic Analysis

Conformational changes in human serum albumin due to numerous modifications that affect its stability and biological activity should be constantly monitored, especially in elderly patients and those suffering from chronic diseases (which include diabetes, obesity, and hypertension). The main goal of this study was to evaluate the effect of a mixture of fatty acids (FA) on the affinity of losartan (LOS, an angiotensin II receptor (AT1) blocker used in hypertension, a first-line treatment with coexisting diabetes) for glycated albumin—simulating the state of diabetes in the body. Individual fatty acid mixtures corresponded to the FA content in the physiological state and in various clinical states proceeding with increased concentrations of saturated (FAS) and unsaturated (FAUS) acids. Based on fluorescence studies, we conclude that LOS interacts with glycated human serum albumin (af)gHSA in the absence and in the presence of fatty acids ((af)gHSAphys, (af)gHSA4S, (af)gHSA8S, (af)gHSA4US, and (af)gHSA8US) and quenches the albumin fluorescence intensity via a static quenching mechanism. LOS not only binds to its specific binding sites in albumins but also non-specifically interacts with the hydrophobic fragments of its surface. Incorrect contents of fatty acids in the body affect the drug pharmacokinetics. A higher concentration of both FAS and FAUS acids in glycated albumin reduces the stability of the complex formed with losartan. The systematic study of FA and albumin interactions using an experimental model mimicking pathological conditions in the body may result in new tools for personalized pharmacotherapy.

Correlation between Hyperkalemia and the Duration of Several Hospitalizations in Patients with Chronic Kidney Disease

(1) Background: This observational study aimed to verify the association between serum potassium levels and hospitalization days in patients with chronic kidney disease in a follow up of nine months. (2) Methods: Patients with chronic kidney disease were divided into group A (180 patients, potassium ≤ 5.1 mEq/L) and B (90 patients, potassium > 5.1 mEq/L). Student’s t-test, Mann–Whitney test, Pearson’s Chi-Square test, Pearson/Spearman’s correlation test and linear regression test were performed in the entire sample and in stage-G4/5 subsample. (3) Results: Groups A and B differed for estimated glomerular filtration rate (eGFR) (34.89 (IQR, 16.24–57.98) vs. 19.8 (IQR, 10.50–32.50) mL/min/1.73 m2; p < 0.0001), hemoglobin (11.64 ± 2.20 vs. 10.97 ± 2.19 g/dL, p = 0.048), sum of hospitalization days (8 (IQR, 6–10) vs. 11 (IQR, 7–15) days; p < 0.0001) and use of angiotensin II receptor blockers (40.2% vs. 53.3%; p = 0.010). Considering patients with eGFR 6–30 mL/min/1.73 m2, differences in the sum of hospitalization days were confirmed. Multivariable regression analysis showed that hyperkalemia is an independent risk factor of increased hospital length. In stage G4-G5, regression analysis showed that hyperkalemia is the only independent risk factor (β = 2.93, 95% confidence interval, 0.077–5.794, p = 0.044). (4) Conclusions: We observed significantly greater odds of increased length of hospital stay among patients with higher potassium, mostly in stages G4–G5 chronic kidney disease.

Association between Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers and Mortality in Patients with Hypertension Hospitalized with COVID-19

Background: Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs) are common hypertension medications. We aimed to investigate the association between treatment with ACEIs/ARBs and disease severity and mortality in patients with hypertension hospitalized for coronavirus disease 2019 (COVID-19). Methods: Information from the medical records of 180 hospitalized patients diagnosed with COVID-19 infection admitted in 2020 to Loghman Hakim Hospital, Tehran, Iran, was collected. Clinical histories, drug therapies, radiological findings, hospital courses, and outcomes were analyzed in all the patients. The demographic and clinical characteristics of the patients were also analyzed, and the percentage of patients with hypertension taking ACEIs/ARBs was compared between survivors and nonsurvivors. Results: The study population consisted of 180 patients at mean±SD age of 67.76±18.72 years. Hypertension was reported in 72 patients (40.0%). Patients with hypertension were older than those without it (mean±SD age =72.35±12.09 y). Among those with hypertension, death occurred in 33 patients (45.8%), of whom 60.6% were men. Fifty-three patients (73.6%) with hypertension were on ACEIs/ARBs. The ACEIs/ARBs group had a significantly lower mortality rate than the non-ACEIs/ARBs group (37.7% vs 68.4%; OR: 0.192; 95% CI: 0.05–0.68; P=0.011). Conclusion: This single-center study found no harmful effects associated with ACEIs/ARBs treatment. Patients on ACEIs/ARBs had a lower rate of mortality and disease severity than the non-ACEIs/ARBs group. Our study supports the current guideline to continue ACEIs/ARBs in patients with hypertension.

Molecular Docking Study and ADMET Profile: Manipulation of Angiotensin II Pathophysiology in COVID-19 by Potentilla Reptans Root Compounds

In the novel SARS-CoV-2 (COVID-19) as a global emergency event, the main reason of the cardiac injury from COVID-19 is angiotensin-converting enzyme 2 (ACE2) targeting in SARS-CoV-2 infection. The inhibition of ACE2 induces an increase in the angiotensin II (Ang II) and the angiotensin II receptor type 1 (AT1R) leading to impaired cardiac function or cardiac inflammatory responses. The ethyl acetate fraction of Potentilla reptans L. root can rescue heart dysfunction, oxidative stress, cardiac arrhythmias and apoptosis. Therefore, isolated components of P. reptans evaluated to identify natural anti-SARS-CoV-2 agents via molecular docking. In silico molecular docking study were carried out using the Auto Dock software on the isolated compounds of Potentilla reptans root. The protein targets of selective ACE and others obtained from Protein Data Bank (PDB). The best binding pose between amino acid residues involved in active site of the targets and compounds was discovered via molecular docking. Furthermore, ADMET properties of the compounds were evaluated. The triterpenoids of P. reptans showed more ACE inhibitory potential than catechin in both domains. They were selective on the nACE domain, especially compound 5. Also, the compound 5 & 6 had the highest binding affinity toward active site of nACE, cACE, AT1R, ACE2, and TNF-α receptors. Meanwhile, compound 3 showed more activity to inhibit TXA2. Drug likeness and ADMET analysis showed that the compounds passed the criteria of drug likeness and Lipinski rules. The current study depicted that P. reptans root showed cardioprotective effect in COVID-19 infection and manipulation of angiotensin II-induced side effects.