Chronic Intermittent Hypobaric Hypoxia Reduces Hypothalamic N-Methyl-d-Aspartate Receptor Activity and Sympathetic Outflow in Spontaneously Hypertensive Rats.

Guo, Xinqi, Hongyu Ma, Ziye Cui, Qiyue Zhao, Ying Zhang, Lu Jia, Liping Zhang, Hui Guo, Xiangjian Zhang, Yi Zhang, Yue Guan, and Huijie Ma. Chronic intermittent hypobaric hypoxia reduces hypothalamic N-Methyl-d-Aspartate Receptor activity and sympathetic outflow in spontaneously hypertensive rats. High Alt Med Biol. 25:77-88, 2024. Objective: This study aims to determine the role of hypothalamic renin-angiotensin system (RAS) in the antihypertensive effect of chronic intermittent hypobaric hypoxia (CIHH). Methods: Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) received 35 days of hypobaric hypoxia simulating an altitude of 4,000 m, 5 h/day. The levels of RAS, blood pressure, and N-methyl-d-aspartate receptor (NMDAR) activities of hypothalamic paraventricular nucleus (PVN) presympathetic neurons from each group of rats were determined. Results: The systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure (MAP) of SHRs significantly decreased from the third week of CIHH treatment. This blood pressure reduction effect could be maintained for at least 2 weeks after stopping the CIHH treatment. CIHH treatment also attenuated the decrease in MAP and renal sympathetic nerve activity induced by hexamethonium administration in SHRs, but not in WKY rats. Furthermore, CIHH reversed the increase in serum angiotensin (Ang)II concentration and the expression of PVN angiotensin-converting enzyme (ACE) and AngII type 1 (AT1) receptors, as well as the decrease in serum Ang1-7 concentration and the expression of PVN ACE2 and Mas receptors in SHRs. In addition, the administration of CIHH resulted in a reduction in the frequency of miniature excitatory postsynaptic currents and amplitude of NMDAR current in PVN presympathetic neurons of SHRs, which means that CIHH decreased the pre- and postsynaptic NMDAR activity of PVN presympathetic neurons in SHRs. However, pretreatment with A779 (a Mas receptor blocker) or AngII abrogated the above effects. Meanwhile, Ang1-7 pretreatment mimicked the CIHH effect on pre- and postsynaptic NMDAR activity of presympathetic neurons in SHRs. Conclusions: Our data indicate that CIHH reduces pre- and postsynaptic NMDAR activity of PVN presympathetic neurons, sympathetic outflow, and blood pressure by decreasing the activity of the ACE/AngII/AT1 axis and increasing the activity of ACE2/Ang1-7/Mas axis in the hypothalamus in hypertension.

Association of Renin-Angiotensin System Inhibition With Liver-Related Events and Mortality in Compensated Cirrhosis.

BACKGROUND & AIMS: While renin-angiotensin system inhibition lowers the hepatic venous gradient, the effect on more clinically meaningful endpoints is less studied. We aimed to quantify the relationship between renin-angiotensin system inhibition and liver-related events (LREs) among adults with compensated cirrhosis. METHODS: In this national cohort study using the Optum database, we quantified the association between angiotensin-converting enzyme (ACE) inhibitor or angiotensin-receptor blocker (ARB) use and LREs (hepatocellular carcinoma, liver transplantation, ascites, hepatic encephalopathy, or variceal bleeding) among patients with cirrhosis between 2009 and 2019. Selective beta-blocker (SBB) users served as the comparator group. We used demographic and clinical features to calculate inverse-probability treatment weighting-weighted cumulative incidences, absolute risk differences, and Cox proportional hazard ratios. RESULTS: Among 4214 adults with cirrhosis, 3155 were ACE inhibitor/ARB users and 1059 were SBB users. In inverse probability treatment weighting-weighted analyses, ACE inhibitor/ARB (vs SBB) users had lower 5-year cumulative incidence (30.6% [95% confidence interval (CI), 27.8% to 33.2%] vs 41.3% [95% CI, 34.0% to 47.7%]; absolute risk difference, -10.7% [95% CI, -18.1% to -3.6%]) and lower risk of LREs (adjusted hazard ratio [aHR], 0.69; 95% CI, 0.60 to 0.80). There was a dose-response relationship: compared with SBB use, ACE inhibitor/ARB prescriptions ≥1 defined daily dose (aHR, 0.65; 95% CI, 0.56 to 0.76) were associated with a greater risk reduction compared with <1 defined daily dose (aHR, 0.87; 95% CI, 0.71 to 1.07). Results were robust across sensitivity analyses such as comparing ACE inhibitor/ARB users with nonusers and as-treated analysis. CONCLUSIONS: In this national cohort study, ACE inhibitor/ARB use was associated with significantly lower risk of LREs in patients with compensated cirrhosis. These results provide support for a randomized clinical trial to confirm clinical benefit.

Angiotensin-Neprilysin inhibition in heart failure with preserved ejection fraction: A meta-analysis of randomized controlled trials.

BACKGROUND: The effect of sacubitril/valsartan on patients with heart failure (HF) with preserved ejection fraction (HFpEF) is a topic of ongoing debate. METHODS: Medline was queried from inception through the last week of May 2023 for randomized studies assessing the effects of sacubitril/valsartan in patients with HFpEF. For continuous outcomes, we pooled either the geometric mean ratios (gMR) or weighted mean difference (WMD) with 95% confidence intervals (CI). For dichotomous outcomes, we pooled Risk ratios (RR) with 95% CI. RESULTS: Four trials were included (N=8,129). Compared to the control, sacubitril/valsartan was associated with a reduction in NT-proBNP levels (gMR: 0.84, 95% CI 0.80, 0.88) and improvement in KCCQ score (WMD: 0.85, 95% CI: 0.02, 1.67). We observed no differences for HF hospitalization (RR: 0.90, 95% CI: 0.79, 1.01), cardiovascular mortality (RR: 0.83, 95% CI: 0.52, 1.32), all-cause mortality (RR: 0.99, 95% CI: 0.86-1.13) and improvement (RR: 1.15, 95% CI: 0.93, 1.42) or worsening (RR: 0.92, 95% CI: 0.78, 1.09) of NYHA class between the sacubitril/valsartan and comparator group. Sacubitril/valsartan was generally safe, and patients were less likely to have a ≥50% decline in eGFR compared to control (RR: 0.60, 95% CI: 0.39, 0.92). CONCLUSION: Pooled analysis suggests that sacubitril/valsartan reduces natriuretic peptide levels and improves the quality of life in patients with HFpEF, which may translate into better clinical outcomes as observed by a numerical trend towards improvement in major HF outcomes with sacubitril/valsartan therapy.

Health and Economic Evaluation of Sacubitril-Valsartan for Heart Failure Management.

Importance: The US Food and Drug Administration expanded labeling of sacubitril-valsartan from the treatment of patients with chronic heart failure (HF) with reduced ejection fraction (EF) to all patients with HF, noting the greatest benefits in those with below-normal EF. However, the upper bound of below normal is not clearly defined, and value determinations across a broader EF range are unknown. Objective: To estimate the cost-effectiveness of sacubitril-valsartan vs renin-angiotensin system inhibitors (RASis) across various upper-level cutoffs of EF. Design, Setting, and Participants: This economic evaluation included participant-level data from the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) and the PARAGON-HF (Prospective Comparison of ARNi with ARB Global Outcomes in HF With Preserved Ejection Fraction) trials. PARADIGM-HF was conducted between 2009 and 2014, PARAGON-HF was conducted between 2014 and 2019, and this analysis was conducted between 2021 and 2023. Main Outcomes and Measures: A 5-state Markov model used risk reductions for all-cause mortality and HF hospitalization from PARADIGM-HF and PARAGON-HF. Quality-of-life differences were estimated from EuroQol-5D scores. Hospitalization and medication costs were obtained from published national sources; the wholesale acquisition cost of sacubitril-valsartan was $7092 per year. Risk estimates and treatment effects were generated in consecutive 5% EF increments up to 60% and applied to an EF distribution of US patients with HF from the Get With the Guidelines-Heart Failure registry. The base case included a lifetime horizon from a health care sector perspective. Incremental cost-effectiveness ratios (ICERs) were estimated at EFs of 60% or less (base case) and at various upper-level EF cutoffs. Results: Among 13 264 total patients whose data were analyzed, for those with EFs of 60% or less, sacubitril-valsartan was projected to add 0.53 quality-adjusted life-years (QALYs) at an incremental lifetime cost of $40 892 compared with RASi, yielding an ICER of $76 852 per QALY. In a probabilistic sensitivity analysis, 95% of the values of the ICER occurred between $71 516 and $82 970 per QALY. Among patients with chronic HF and an EF of 60% or less, treatment with sacubitril-valsartan vs RASis would be at least of economic intermediate value (ICER <$180 000 per QALY) at a sacubitril-valsartan cost of $10 242 or less per year, of high economic value (ICER <$60 000 per QALY) at a cost of $3673 or less per year, and cost-saving at a cost of $338 or less per year. The ICERs were $67 331 per QALY, $59 614 per QALY, and $56 786 per QALY at EFs of 55% or less, 50% or less, and 45% or less, respectively. Treatment with sacubitril-valsartan in only those with EFs of 45% or greater (up to ≤60%) yielded an ICER of $127 172 per QALY gained; treatment was more cost-effective in those at the lower end of this range (ICER of $100 388 per QALY gained for those with EFs of 45%-55%; ICER of $84 291 per QALY gained for those with EFs of 45%-50%). Conclusions and Relevance: Cost-effectiveness modeling provided an ICER for treatment with sacubitril-valsartan vs RASis consistent with high economic value for patients with reduced and mildly reduced EFs (≤50%) and at least intermediate value at the current undiscounted wholesale acquisition cost price at an EF of 60% or less. Treatment was more cost-effective at lower EF ranges. These findings may have implications for coverage decisions and value assessments in contemporary clinical practice guidelines.

Blood pressure management and long-term outcomes in kidney transplantation: a holistic view over a 35-year period.

INTRODUCTION: Hypertension is a burden for most kidney transplant recipients. Whether respect of hypertension guidelines results in better outcomes is unknown. METHODS: In this multicenter study, office blood pressure at 12 months following transplantation (i.e., after > 20 outpatient visits), and survival were assessed over 35 years among 2004 consecutive kidney transplant recipients who received a first kidney graft from 1985 to 2019 (follow-up: 26,232 patient-years). RESULTS: Antihypertensive medications were used in 1763/2004 (88.0%) patients. Renin-angiotensin-system blockers were used in 35.6% (47.1% when proteinuria was > 0.5 g/day) and calcium-channel blockers were used in 6.0% of patients. Combined treatment including renin-angiotensin-system-blockers, calcium-channel blockers and diuretics was used in 15.4% of patients receiving ≥ 3 antihypertensive drugs. Blood pressure was controlled in 8.3%, 18.8% and 43.1%, respectively, depending on definition (BP < 120/80, < 130/80, < 140/90 mmHg, respectively) and has not improved since the year 2001. Two-thirds of patients with uncontrolled blood pressure received < 3 antihypertensive classes. Low sodium intake < 2 g/day (vs ≥ 2) was not associated with better blood pressure control. Uncontrolled blood pressure was associated with lower patient survival (in multivariable analyses) and graft survival (in univariate analyses) vs controlled hypertension or normotension. Low sodium intake and major antihypertensive classes had no influence on patient and graft survival. CONCLUSIONS: Pharmacological recommendations and sodium intake reduction are poorly respected, but even when respected, do not result in better blood pressure control, or patient or graft survival. Uncontrolled blood pressure, not the use of specific antihypertensive classes, is associated with reduced patient, and to a lesser extent, reduced graft survival, even using the 120/80 mmHg cut-off.

Targeting the renin angiotensin system for respiratory diseases.

Renin-angiotensin system (RAS) plays an indispensable role in regulating blood pressure through its effects on fluid and electrolyte balance. As an aside, cumulative evidence from experimental to clinical studies supports the notion that dysregulation of RAS contributes to the pro-inflammatory, pro-oxidative, and pro-fibrotic processes that occur in pulmonary diseases like asthma, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and acute lung injury (ALI). Pharmacological intervention of the various RAS components can be a novel therapeutic strategy for the treatment of these respiratory diseases. In this chapter, we first give a recent update on the RAS, and then compile, review, and analyse recent reports on targeting RAS components as treatments for respiratory diseases. Inhibition of the pro-inflammatory renin, angiotensin-converting enzyme (ACE), angiotensin (Ang) II, and Ang II type 1 receptor (AT1R) axis, and activation of the protective ACE2, AT2R, Ang (1-7), and Mas receptor axis have demonstrated varying degrees of efficacies in experimental respiratory disease models or in human trials. The newly identified alamandine/Mas-related G-protein-coupled receptor member D pathway has shown some therapeutic promise as well. However, our understanding of the RAS ligand-and-receptor interactions is still inconclusive, and the modes of action and signaling cascade mediating the newly identified RAS receptors remain to be better characterized. Clinical data are obviously lacking behind the promising pre-clinical findings of certain well-established molecules targeting at different pathways of the RAS in respiratory diseases. Translational human studies should be the focus for RAS drug development in lung diseases in the next decade.

[Effects of angiotensin-converting enzyme on reproduction of Culex pipiens pallens].

OBJECTIVE: To investigate the role of angiotensin-converting enzyme (ACE) in the reproduction of Culex pipiens pallens, so as to provide insights into selection of targets for controlling mosquito vector populations. METHODS: Cx. pipiens pallens was collected from Tangkou County, Shandong Province in 2009. Female and male mosquitoes were selected at 72 hours post-eclosion, and quantitative real-time reverse transcription PCR (qPCR) assay was used to detect the expression of ACE gene in the whole body and reproductive tissues of male mosquitoes and fertilized female mosquitoes before (0 h) and after blood meals (24, 48, 72 h), respectively. Then, 150 female and 150 male mosquitoes at 0 to 4 hours post-eclosion were selected and divided into the wild-type group (WT group), small interfering RNA-negative control group (siNC group) and small interfering RNA-ACE group (siACE group), of 50 mosquitoes in each group. Mosquitoes in the WT group were given no treatment, and mosquitoes in the siNC and siACE groups were given microinjection of siNC and siACE into the hemolymph at a dose of 0.3 µg per mosquito. The knockdown efficiency was checked using qPCR assay, and the reproductive phenotype of mosquitoes was observed. RESULTS: The relative ACE gene expression was higher in the whole body of male mosquitoes (5.467 ± 1.006) relative to females (1.199 ± 0.241) (t = 5.835, P = 0.004) at 72 h post-eclosion, and the highest ACE expression was seen in reproductive tissues of male mosquitoes (199.100 ± 24.429), which was 188.3 times higher than in remaining tissues (1.057 ± 0.340) (t = 6.602, P = 0.002). Blood meal induced high ACE expression in all body tissues of fertilized female mosquitoes, with peak expression at 24 h after blood meals (14.957 ± 2.815), which was 14.8 times higher than that before blood meals (1.009 ± 0.139) (P = 0.002). The transcriptional level of ACEs continued to increase in the ovaries of female mosquitoes after blood meals during the vitellogenesis phase, peaking at 48 h after blood meals (5.500 ± 0.734), which was 5.1 times higher than that before blood meals (1.072 ± 0.178) (P = 0.002). Small RNA interference targeting ACE resulted in a 57.2% reduction in ACE expression in female mosquitoes in the siACE group (0.430 ± 0.070) relative to the siNC group (1.002 ± 0.070) (P = 0.001), and a 41.1% reduction in male mosquitoes in the siACE group (0.588 ± 0.067) relative to the siNC group (1.008 ± 0.131) (P = 0.016). Knockdown of ACE expression resulted in a 48.0% decrease in the number of eggs laid by female mosquitoes in the siACE group [(94.000 ± 27.386) eggs] relative to the siNC group [(180.800 ± 27.386)] (P < 0.001), and a 45.0% decrease in the number of eggs laid by wild female mosquitoes mated with males in the siACE group [(104.500 ± 20.965) eggs] relative to the siNC group [(190.050 ± 10.698) eggs] (P < 0.001). CONCLUSIONS: Reduced ACE expression may inhibit the fecundity of male and female mosquitoes, and ACE may be as a potential target for mosquito vector population suppression.

Guideline-directed medical therapy for HFrEF: sequencing strategies and barriers for life-saving drug therapy.

Multiple landmark trials have helped to advance the treatment of heart failure with reduced ejection fraction (HFrEF) significantly over the past decade. These trials have led to the introduction of four main drug classes into the 2021 ESC guideline, namely angiotensin-receptor neprilysin inhibitors/angiotensin-converting-enzyme inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 inhibitors. The life-saving effect of these therapies has been shown to be additive and becomes apparent within weeks, which is why maximally tolerated or target doses of all drug classes should be strived for as quickly as possible. Recent evidence, such as the STRONG-HF trial, demonstrated that rapid drug implementation and up-titration is superior to the traditional and more gradual step-by-step approach where valuable time is lost to up-titration. Accordingly, multiple rapid drug implementation and sequencing strategies have been proposed to significantly reduce the time needed for the titration process. Such strategies are urgently needed since previous large-scale registries have shown that guideline-directed medical therapy (GDMT) implementation is a challenge. This challenge is reflected by generally low adherence rates, which can be attributed to factors considering the patient, health care system, and local hospital/health care provider. This review of the four medication classes used to treat HFrEF seeks to present a thorough overview of the data supporting current GDMT, discuss the obstacles to GDMT implementation and up-titration, and identify multiple sequencing strategies that could improve GDMT adherence. Sequencing strategies for GDMT implementation. GDMT: guideline-directed medical therapy; ACEi: angiotensin-converting enzyme inhibitor; ARB: Angiotensin II receptor blocker; ARNi: angiotensin receptor-neprilysin inhibitor; BB: beta-blocker; MRA: mineralocorticoid receptor antagonist; SGLT2i: sodium-glucose co-transporter 2 inhibitor.

Safety and efficacy of new potassium binders on hyperkalemia management in patients with heart failure: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Hyperkalemia leads to suboptimal use of evidence-based therapies in patients with heart failure (HF). Therefore, we aimed to assess whether new potassium binders are effective and safe to promote medical optimization in patients with HF. METHODS: MEDLINE, Cochrane, and Embase were searched for randomized controlled trials (RCTs) that reported outcomes after initiation of Patiromer or Sodium Zirconium Cyclosilicate (SZC) versus placebo in patients with HF at high risk of hyperkalemia development. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random effects model. Quality assessment and risk of bias were performed according to Cochrane recommendations. RESULTS: A total of 1432 patients from 6 RCTs were included, of whom 737 (51.5%) patients received potassium binders. In patients with HF, potassium binders increased the use of renin-angiotensin-aldosterone inhibitors (RR 1.14; 95% CI 1.02-1.28; p = 0.021; I2 = 44%) and reduced the risk of hyperkalemia (RR 0.66; 95% CI 0.52-0.84; p < 0.001; I2 = 46%). The risk of hypokalemia was significantly increased in patients treated with potassium binders (RR 5.61; 95% CI 1.49-21.08; p = 0.011; I2 = 0%). There was no difference between groups in all-cause mortality rates (RR 1.13; 95% CI 0.59-2.16; p = 0.721; I2 = 0%) or in adverse events leading to drug discontinuation (RR 1.08; 95% CI 0.60-1.93; p = 0.801; I2 = 0%). CONCLUSION: The use of new potassium binders Patiromer or SZC in patients with HF at risk for hyperkalemia increased the rates of medical therapy optimization with renin-angiotensin-aldosterone inhibitors and reduced the incidence of hyperkalemia, at the cost of an increased prevalence of hypokalemia.

Aerobic Physical Exercise is Essential for Cardiac Autonomic Regulation in Hypertensive Patients Undergoing Chronic Treatment with Renin- Angiotensin System Inhibitors.

BACKGROUND: Hypertension treatment with renin-angiotensin system inhibitors (RASi) presents contradictions about the recovery of damage in cardiovascular autonomic modulation characterized by reduced heart rate variability (HRV) and increased blood pressure variability (BPV). Conversely, the association of RASi with physical training can influence achievements in cardiovascular autonomic modulation. OBJECTIVE: To investigate the effects of aerobic physical training on hemodynamics and cardiovascular autonomic modulation in hypertensive volunteers untreated and treated with RASi. METHODS: A non-randomized controlled trial in which 54 men (≅ 40-60 years old) with a history of hypertension for >2 years were allocated in accordance with their characteristics into three groups: untreated (Control; n=16), treated with type 1 angiotensin II (AT1) receptor blocker (losartan; n=21), and treated with angiotensin-converting enzyme inhibitor (enalapril; n=17). All participants underwent hemodynamic, metabolic, and cardiovascular autonomic evaluation using baroreflex sensitivity (BRS) and spectral analysis of HRV and BPV, before and after 16 weeks of supervised aerobic physical training. RESULTS: The volunteers treated with RASi had lower BPV and HRV, both in the supine position and in the tilt test, with the losartan group having the lowest values. Aerobic physical training increased HRV and BRS in all groups. However, the association of enalapril with physical training appears to be more prominent. CONCLUSION: Long-term treatment with enalapril and losartan may harm the autonomic modulation of HRV and BRS. Aerobic physical training is essential to promote positive adjustments in the autonomic modulation of HRV and BRS in hypertensive patients treated with RASi, especially with enalapril.

Angiotensin-Neprilysin Inhibition in Patients With Mildly Reduced or Preserved Ejection Fraction and Worsening Heart Failure.

BACKGROUND: U.S. guidelines recommend consideration of sacubitril/valsartan in chronic heart failure (HF) and mildly reduced or preserved ejection fraction (EF). Whether initiation is safe and effective in EF >40% after a worsening heart failure (WHF) event is unknown. OBJECTIVES: PARAGLIDE-HF (Prospective comparison of ARNI with ARB Given following stabiLization In DEcompensated HFpEF) assessed sacubitril/valsartan vs valsartan in EF >40% following a recent WHF event. METHODS: PARAGLIDE-HF is a double-blind, randomized controlled trial of sacubitril/valsartan vs valsartan in patients with EF >40% enrolled within 30 days of a WHF event. The primary endpoint was time-averaged proportional change in amino terminal pro-B-type natriuretic peptide (NT-proBNP) from baseline through Weeks 4 and 8. A secondary hierarchical outcome (win ratio) consisted of: 1) cardiovascular death; 2) HF hospitalizations; 3) urgent HF visits; and 4) change in NT-proBNP. RESULTS: In 466 patients (233 sacubitril/valsartan; 233 valsartan), time-averaged reduction in the NT-proBNP was greater with sacubitril/valsartan (ratio of change: 0.85; 95% CI: 0.73-0.999; P = 0.049). The hierarchical outcome favored sacubitril/valsartan but was not significant (unmatched win ratio: 1.19; 95% CI: 0.93-1.52; P = 0.16). Sacubitril/valsartan reduced worsening renal function (OR: 0.61; 95% CI: 0.40-0.93) but increased symptomatic hypotension (OR: 1.73; 95% CI: 1.09-2.76). There was evidence of a larger treatment effect in the subgroup with EF ≤60% for NT-proBNP change (0.78; 95% CI: 0.61-0.98) and the hierarchical outcome (win ratio: 1.46; 95% CI: 1.09-1.95). CONCLUSIONS: Among patients with EF >40% stabilized after WHF, sacubitril/valsartan led to greater reduction in plasma NT-proBNP levels and was associated with clinical benefit compared with valsartan alone, despite more symptomatic hypotension. (Prospective comparison of ARNI with ARB Given following stabiLization In DEcompensated HFpEF; NCT03988634).

Gentisic acid protects against diabetic nephropathy in Nicotinamide-Streptozotocin administered male mice by attenuating oxidative stress and inflammation: The role of miR-200a/Keap1/Nrf2 pathway, renin-angiotensin system (RAS) and NF-кB.

Oxidative stress and inflammation play a pivotal role in the pathogenesis of diabetic nephropathy (DN). Local renin-angiotensin systems (RAS) contribute to the pathogenesis and progression of DN by exacerbating oxidative stress and inflammation.Gentisic acid (GA), a phenolic compound and also a metabolite of aspirin, is reported to possess antioxidant and anti-inflammatory properties. However, the protective effects of GA against DN remain to be elucidated. Nicotinamide (120 mg/kg) and streptozotocin (65 mg/kg) were used to induce diabetes in male mice. Oral administration of GA once daily for 2 weeks (100 mg/kg) ameliorated diabetes-induced renal injury by reducing plasma creatinine, urea, blood urea nitrogen, and urinary albuminuria levels. Diabetic mice showed a significant increase in total oxidant status and malondialdehyde, along with decreased catalase, superoxide dismutase, and glutathione peroxidase in the kidney tissue, which was ameliorated in the GA-treated mice. Histopathological analysis showed that GA treatment reduced diabetes-induced renal injury. Furthermore, GA treatment was associated with the downregulation of miR-125b, nuclear factor kappa beta (NF-кB), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), and upregulation of interleukin-10 (IL-10), miR-200a, and nuclear factor erythroid 2-related factor 2 (Nrf2) in the renal tissue. GA treatment also downregulated angiotensin-converting enzyme 1 (ACE1), angiotensin II receptor 1 (AT1R), and NADPH oxidase 2 (NOX 2) and upregulated angiotensin-converting enzyme 2 (ACE2). In conclusion, the ameliorative effects of GA against DN may be attributed to its powerful antioxidant and anti-inflammatory properties through the downregulation of NF-кB, upregulation of Nrf2, and modulation of RAS in renal tissue.

Impact of early initiation of renin-angiotensin blockade on renal function and clinical outcomes in patients with hypertensive emergency: a retrospective cohort study.

BACKGROUND: Hypertensive emergency is a critical disease that causes multifaceted sequelae, including end-stage kidney disease and cardiovascular disease. Although the renin-angiotensin-aldosterone (RAA) system is enormously activated in this disease, there are few reports that attempt to characterize the effect of early use of RAA inhibitors (RASi) on the temporal course of kidney function. METHODS: This retrospective cohort study was conducted to clarify whether the early use of RASi during hospitalization offered more favorable benefits on short-term renal function and long-term renal outcomes in patients with hypertensive emergencies. We enrolled a total of 49 patients who visited our medical center with acute severe hypertension and multiple organ dysfunction between April 2012 and August 2020. Upon admission, the patients were treated with intravenous followed by oral antihypertensive drugs, including RASi and Ca channel blockers (CCB). Kidney function as well as other laboratory and clinical parameters were compared between RASi-treated and CCB- treated group over 2 years. RESULTS: Antihypertensive treatment effectively reduced blood pressure from 222 ± 28/142 ± 21 to 141 ± 18/87 ± 14 mmHg at 2 weeks and eGFR was gradually restored from 33.2 ± 23.3 to 40.4 ± 22.5 mL/min/1.73m2 at 1 year. The renal effect of antihypertensive drugs was particularly conspicuous when RASi was started in combination with other conventional antihypertensive drugs at the early period of hospitalization (2nd day [IQR: 1-5.5]) and even in patients with moderately to severely diminished eGFR (< 30 mL/min/1.73 m2) on admission. In contrast, CCB modestly restored eGFR during the observation period. Furthermore, renal survival probabilities were progressively deteriorated in patients who had manifested reduced eGFR (< 15 mL/min/1.73 m2) or massive proteinuria (urine protein/creatinine ≥ 3.5 g/gCr) on admission. Early use of RASi was associated with a favorable 2-year renal survival probability (0.90 [95%CI: 0.77-1.0] vs. 0.63 [95%CI: 0.34-0.92] for RASi ( +) and RASi (-), respectively, p = 0.036) whereas no apparent difference in renal survival was noted for CCB. CONCLUSIONS: Early use of RASi contributes to the renal functional recovery from acute reduction in eGFR among patients with hypertensive emergencies. Furthermore, RASi offers more favorable effect on 2-year renal survival, compared with CCB.

Protein nanopore reveals the renin-angiotensin system crosstalk with single-amino-acid resolution.

The discovery of crosstalk effects on the renin-angiotensin system (RAS) is limited by the lack of approaches to quantitatively monitor, in real time, multiple components with subtle differences and short half-lives. Here we report a nanopore framework to quantitatively determine the effect of the hidden crosstalk between angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) on RAS. By developing an engineered aerolysin nanopore capable of single-amino-acid resolution, we show that the ACE can be selectively inhibited by ACE2 to prevent cleavage of angiotensin I, even when the concentration of ACE is more than 30-fold higher than that of ACE2. We also show that the activity of ACE2 for cleaving angiotensin peptides is clearly suppressed by the spike protein of SARS-CoV-2. This leads to the relaxation of ACE and the increased probability of accumulation of the principal effector angiotensin II. The spike protein of the SARS-CoV-2 Delta variant is demonstrated to have a much greater impact on the crosstalk than the wild type.

A case of idiopathic nodular glomerulosclerosis successfully treated by intensive blockade of the renin-angiotensin-aldosterone system.

Idiopathic nodular glomerulosclerosis has a poor renal prognosis and is characterized by diffuse nodular glomerulosclerotic lesions in the absence of diabetic mellitus. Here, we report the case of a 69-year-old woman with no smoking history who developed renal dysfunction and proteinuria in the absence of overt diabetes or obesity. A biopsy specimen showed nodular mesangial sclerosis with arteriolar hyalinosis and severe large-vessel arteriosclerosis, leading to a diagnosis of idiopathic nodular glomerulosclerosis. Addition of esaxerenone to her existing renin-angiotensin-aldosterone inhibitor therapy led to a rapid decrease in the proteinuria levels and the maintenance of renal function without any complications for more than a year. The results suggest that intensive renin-angiotensin-aldosterone blockade might be an effective treatment for idiopathic nodular glomerulosclerosis.

L-arginine and lisinopril supplementation protects against sodium fluoride-induced nephrotoxicity and hypertension by suppressing mineralocorticoid receptor and angiotensin-converting enzyme 3 activity.

Sodium fluoride (NaF) is one of the neglected environmental toxicants that has continued to silently cause toxicity to both humans and animals. NaF is universally present in water, soil, and atmosphere. The persistent and alarming rate of increase in cardiovascular and renal diseases caused by chemicals such as NaF in mammalian tissues has led to the use of various drugs for the treatment of these diseases. The present study aimed at evaluating the renoprotective and antihypertensive effects of L-arginine against NaF-induced nephrotoxicity. Thirty male Wistar rats (150-180 g) were used in this study. The rats were randomly divided into five groups of six rats each as follows: Control, NaF (300 ppm), NaF + L-arginine (100 mg/kg), NaF + L-arginine (200 mg/kg), and NaF + lisinopril (10 mg/kg). Histopathological examination and immunohistochemistry of renal angiotensin-converting enzyme (ACE) and mineralocorticoid receptor (MCR) were performed. Markers of renal damage, oxidative stress, antioxidant defense system, and blood pressure parameters were determined. L-arginine and lisinopril significantly (P < 0.05) ameliorated the hypertensive effects of NaF. The systolic, diastolic, and mean arterial blood pressure of the treated groups were significantly (P < 0.05) reduced compared with the hypertensive group. This finding was concurrent with significantly increased serum bioavailability of nitric oxide in the hypertensive rats treated with L-arginine and lisinopril. Also, there was a significant reduction in the level of blood urea nitrogen and creatinine of hypertensive rats treated with L-arginine and lisinopril. There was a significant (P < 0.05) reduction in markers of oxidative stress such as malondialdehyde and protein carbonyl and concurrent increase in the levels of antioxidant enzymes in the kidney of hypertensive rats treated with L-arginine and lisinopril. The results of this study suggest that L-arginine and lisinopril normalized blood pressure, reduced oxidative stress, and the expression of renal ACE and mineralocorticoid receptor, and improved nitric oxide production. Thus, L-arginine holds promise as a potential therapy against hypertension and renal damage.

Dual therapy with an angiotensin receptor blocker and a JAK1/2 inhibitor attenuates dialysate-induced angiogenesis and preserves peritoneal membrane structure and function in an experimental CKD rat model.

BACKGROUND: Peritoneal dialysis (PD) is limited by reduced efficacy over time. We previously showed that a Janus kinase 1/2 inhibitor (JAK1/2i) reduced inflammation, hypervascularity and fibrosis induced by 4.25% dextrose dialysate (4.25%D) intraperitoneally (IP) infused for 10 days in rats with normal kidney function. JAK/STAT signalling mediates inflammatory pathways, including angiotensin signalling. We now tested the effect of long-term JAK1/2i and/or an angiotensin receptor blocker (ARB) on peritoneal membrane (PM) in polycystic kidneys (PCK) rats infused with 4.25%D. METHODS: Except for controls, all PCK rats had a tunnelled PD catheter: (1) no infusions; (2) 4.25%D; (3) 4.25%D + JAK1/2i (5 mg/kg); (4) 4.25%D +losartan (5 mg/kg); and (5) 4.25%D + losartan +JAK1/2i (5 mg/kg each) IP BID × 16 weeks (N = 5/group). PM VEGFR2 staining areas and submesothelial compact zone (SMCZ) width were morphometrically measured. Peritoneal equilibration testing measured peritoneal ultrafiltration (UF) by calculating dialysate glucose at time 0 and 90 min (D/D0 glucose). RESULTS: 4.25%D caused hypervascularity, SMCZ widening, fibrosis and UF functional decline in PCK rats. Angiogenesis was significantly attenuated by JAK1/2i ± ARB but not by ARB monotherapy. Both treatments reduced SMCZ area. UF was preserved consistently by dual therapy (p < 0.05) but with inconsistent responses by monotherapies. CONCLUSION: Long-term JAK1/2i ± ARB reduced angiogenesis and fibrosis, and the combination consistently maintained UF. In clinical practice, angiotensin inhibition has been advocated to maintain residual kidney function. Our study suggests that adding JAK1/2i to angiotensin inhibition may preserve PM structure and UF.

Short-term effects of goat milk yogurt-containing angiotensin-converting enzyme inhibitory peptides and two raisin varieties on subjective appetite, blood pressure and glycaemic responses in healthy adults. Results from a randomised clinical trial.

Goat milk yogurt (GMY) and raisins are popular foods with a favourable nutrient profile. Our aim was to determine the glycaemic index (GI) and postprandial responses to GMY-containing angiotensin-converting enzyme inhibitory (ACE-I) peptides carrying the RPKHPINHQ isracidin fragment and two Greek raisin varieties in an acute feeding setting. A total of twelve healthy participants (four male and eight female) consumed breakfast study foods containing 25 g available carbohydrate on seven occasions over a 3- to 9-week period: food 1: D-glucose (25 g) served as the control and was consumed on three separate occasions; food 2: GMY (617·28 g); food 3: Corinthian raisins (37·76 g); food 4: Sultana raisins (37·48 g) and food 5: GMY & C (308·64 g GMY and 18·88 g C). Postprandial glucose was measured over a 2 h period for the determination of GI and glycaemic load (GL). Subjective appetite ratings (hunger, fullness and desire to eat) were assessed by visual analogue scales (100 mm) at 0­120 min. Blood pressure (systolic and diastolic; BP) was measured at baseline and 120 min. GMY provided low GI (26), C and S provided high GI/low GL (75/10 and 70/9, respectively) and GMYC provided low GI (47) values on glucose scale compared with D-glucose. Peak blood glucose rise was significantly lower only for GMY and GMYC compared with reference food (D-Glucose), as well as C and S (Pfor all < 0·05). No differences were observed between test foods for fasting glucose, BP and subjective appetite. In conclusion, GMY and GMYC attenuated postprandial glycaemic responses, which may offer advantages to glycaemic control.

Evaluating Guideline Directed Medical Therapy in Patients With Heart Failure With Reduced Ejection Fraction Post-coronary Artery Bypass Grafting.

Background: Limited evidence regarding the use of guideline directed medical therapy (GDMT) in patients with heart failure with reduced ejection fraction (HFrEF) undergoing coronary artery bypass grafting (CABG) is available. Objective: The purpose of this study was to characterize prescription of HFrEF GDMT use before and after CABG. Methods: A retrospective analysis of adult patients with an ejection fraction ≤40% undergoing CABG was performed. The primary objective was to evaluate patients receiving HFrEF GDMT, defined as a heart failure beta-blocker (HFBB) and a renin-angiotensin inhibitor preoperatively and postoperatively. Secondary outcomes included dosing, percent of patients on each individual therapy, mineralocorticoid receptor antagonist (MRA) use, and the combination thereof. The follow up period was 1 year. Results: Thirty-eight patients met criteria for inclusion. Prior to CABG, 52.6% of patients were receiving HFrEF GDMT. The prescribing rate of HFrEF GDMT was not significantly higher at any point within 1 year postoperatively (P = .299). The rate of renin-angiotensin inhibitors, HFBB, and aldosterone antagonists use significantly increased from 13.2% preoperatively to 36.8% at 1 year after CABG (P = .022). Doses of individual therapies were not significantly different across all time points preoperatively and postoperatively. Conclusion: HFrEF GDMT use and doses of individual therapies after CABG were not maximized. Collaborative efforts between cardiac surgeons, heart failure cardiologists, and pharmacists could be used to optimize HFrEF GDMT use and dose titration.