The Use of Angiotensin II for the Treatment of Post-cardiopulmonary Bypass Vasoplegia

PURPOSE: Vasoplegia is a common complication after cardiac surgery and is related to the use of cardiopulmonary bypass (CPB). Despite its association with increased morbidity and mortality, no consensus exists in terms of its treatment. In December 2017, angiotensin II (AII) was approved by the Food and Drug Administration (FDA) for use in vasodilatory shock; however, except for the ATHOS-3 trial, its use in vasoplegic patients that underwent cardiac surgery on CPB has mainly been reported in case reports. Thus, the aim of this review is to collect all the clinically relevant data and describe the pharmacologic mechanism, efficacy, and safety of this novel pharmacologic agent for the treatment of refractory vasoplegia in this population. METHODS: Two independent reviewers performed a systematic search in PubMed, Embase, Web of Science, and Cochrane Library using relevant MeSH terms (Angiotensin II, Vasoplegia, Cardiopulmonary Bypass, Cardiac Surgical Procedures). RESULTS: The literature search yielded 820 unique articles. In total, 9 studies were included. Of those, 2 were randomized clinical trials (RCTs) and 6 were case reports and 1 was a retrospective cohort study. CONCLUSIONS: AII appears to be a promising means of treatment for patients with post-operative vasoplegia. It is demonstrated to be effective in raising blood pressure, while no major adverse events have been reported. It remains uncertain whether this agent will be broadly available and whether it will be more advantageous in the clinical management of vasoplegia compared to other available vasopressors. For that reason, we should contain our eagerness and enthusiasm regarding its use until supplementary knowledge becomes available. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10557-020-07098-3) contains supplementary material, which is available to authorized users

Megalin: a Novel Determinant of Renin-Angiotensin System Activity in the Kidney?

Purpose of Review: Megalin is well known for its role in the reabsorption of proteins from the ultrafiltrate. Recent studies suggest that megalin also reabsorbs renin and angiotensinogen. Indeed, without megalin urinary renin and angiotensinogen levels massively increase, and even prorenin becomes detectable in urine. Recent Findings: Intriguingly, megalin might also contribute to renal angiotensin production, as evidenced from studies in megalin knockout mice. This review discusses these topics critically, concluding that urinary renin-angiotensin system components reflect diminished reabsorption rather than release from renal tissue sites and that alterations in renal renin levels or megalin-dependent signaling need to be ruled out before concluding that angiotensin production at renal tissue sites is truly megalin dependent. Summary: Future studies should evaluate megalin-mediated renin/angiotensinogen transcytosis (allowing interstitial angiotensin generation), and determine whether megalin prefers prorenin over renin, thus explaining why urine normally contains no prorenin

Long-Term Use of Aldosterone-Receptor Antagonists in Uncontrolled Hypertension: A Retrospective Analysis

Background. The long-term efficacy of aldosterone-receptor antagonists (ARAs) as add-on treatment in uncontrolled hypertension has not yet been reported. Methods. Data from 123 patients (21 with primary aldosteronism, 102 with essential hypertension) with difficult-to-treat hypertension who received an ARA between May 2005 and September 2009 were analyzed retrospectively for their blood pressure (BP) and biochemical response at first followup after start with ARA and the last follow-up available. Results. Systolic BP decreased by 22 ± 20 and diastolic BP by 9.4 ± 12 mmHg after a median treatment duration of 25 months. In patients that received treatment >5 years, SBP was 33 ± 20 and DBP was 16 ± 13 mmHg lower than at baseline. Multivariate analysis revealed that baseline BP and follow-up duration were positively correlated with BP response. Conclusion. Add-on ARA treatment in difficult-to-treat hypertension results in a profound and sustained BP reduction

Nitric Oxide-cGMP Signaling in Hypertension:Current and Future Options for Pharmacotherapy

For the treatment of systemic hypertension, pharmacological intervention in nitric oxide-cyclic guanosine monophosphate signaling is a well-explored but unexploited option. In this review, we present the identified drug targets, including oxidases, mitochondria, soluble guanylyl cyclase, phosphodiesterase 1 and 5, and protein kinase G, important compounds that modulate them, and the current status of (pre)clinical development. The mode of action of these compounds is discussed, and based upon this, the clinical opportunities. We conclude that drugs that directly target the enzymes of the nitric oxide-cyclic guanosine monophosphate cascade are currently the most promising compounds, but that none of these compounds is under investigation as a treatment option for systemic hypertension

Acute renal effects of the GLP-1 receptor agonist exenatide in overweight type 2 diabetes patients: a randomised, double-blind, placebo-controlled trial

Aims/hypothesis: This study aimed to investigate the acute renal effects of the glucagon-like peptide-1 receptor agonist (GLP-1RA) exenatide in type 2 diabetes patients. Methods: We included overweight (BMI 25–40 kg/m2) men and postmenopausal women, aged 35–75 years with type 2 diabetes (HbA1c 48–75 mmol/mol; 6.5–9.0%) and estimated GFR ≥ 60 ml min−1 1.73 m−2. Exenatide or placebo (NaCl solution, 154 mmol/l) was administrated intravenously in an acute, randomised, double-blind, placebo-controlled trial conducted at the Diabetes Center VU University Medical Center (VUMC). GFR (primary endpoint) and effective renal plasma flow (ERPF) were determined by inulin and para-aminohippurate clearance, respectively, based on timed urine sampling. Filtration fraction (FF) and effective renal vascular resistance (ERVR) were calculated, and glomerular hydrostatic pressure (PGLO) and vascular resistance of the afferent (RA) and efferent (RE) renal arteriole were estimated. Tubular function was assessed by absolute and fractional excretion of sodium (FENa), potassium (FEK) and urea (FEU), in addition to urine osmolality, pH and free water clearance. Renal damage markers, BP and plasma glucose were also determined. Results: Of the 57 patients randomised by computer, 52 were included in the final analyses. Exenatide (n = 24) did not affect GFR (mean difference +2 ± 3 ml min−1 1.73 m−2, p = 0.489), ERPF, FF, ERVR or PGLO, compared with placebo (n = 28). Exenatide increased RA (p < 0.05), but did not change RE. Exenatide increased FENa, FEK, urine osmolality and pH, while FEU, urinary flow and free water clearance were decreased (all p < 0.05). Osmolar clearance and renal damage makers were not affected. Diastolic BP and mean arterial pressure increased by 3 ± 1 and 6 ± 2 mmHg, respectively, whereas plasma glucose decreased by 1.4 ± 0.1 mmol/l (all p < 0.05). Conclusions/interpretation: Exenatide infusion does not acutely affect renal haemodynamics in overweight type 2 diabetes patients at normal filtration levels. Furthermore, acute GLP-1RA administration increases proximal sodium excretion in these patients. Trial registration: ClincialTrials.gov NCT01744236 Funding: The research leading to these results has been funded from: (1) the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement number 282521 – the SAFEGUARD project; and (2) the Dutch Kidney Foundation, under grant agreement IP12.87

Targeting angiotensinogen with RNA-based therapeutics

PURPOSE OF REVIEW: To summarize all available data on targeting angiotensinogen with RNA-based therapeutics as a new tool to combat cardiovascular diseases. RECENT FINDINGS: Liver-targeted, stable antisense oligonucleotides and small interfering RNA targeting angiotensinogen are now available, and may allow treatment with at most a few injections per year, thereby improving adherence. Promising results have been obtained in hypertensive animal models, as well as in rodent models of atherosclerosis, polycystic kidney disease and pulmonary fibrosis. The next step will be to evaluate the optimal degree of suppression, synergy with existing renin-angiotensin-aldosterone system blockers, and to determine harmful effects of suppressing angiotensinogen in the context of common comorbidities, such as heart failure and chronic kidney disease. SUMMARY: Targeting angiotensinogen with RNA-based therapeutics is a promising new tool to treat hypertension and diseases beyond. Their long-lasting effects are particularly exciting, and if translated to a clinical application of at most a few administrations per year, may help to eliminate nonadherence

MicroRNA-148a Regulates Low-Density Lipoprotein Metabolism by Repressing the (Pro)renin Receptor

High plasma LDL cholesterol (LDL-c) concentration is a major risk factor for atherosclerosis. Hepatic LDL receptor (LDLR) regulates LDL metabolism, and thereby plasma LDL-c concentration. Recently, we have identified the (pro)renin receptor [(P)RR] as a novel regulator of LDL metabolism, which regulates LDLR degradation and hence its protein abundance and activity. In silico analysis suggests that the (P)RR is a target of miR-148a. In this study we determined whether miR-148a could regulate LDL metabolism by regulating (P)RR expression in HepG2 and Huh7 cells. We found that miR-148a suppressed (P)RR expression by binding to the 3’-untranslated regions (3’-UTR) of the (P)RR mRNA. Mutating the binding sites for miR-148a in the 3’-UTR of (P)RR mRNA completely abolished the inhibitory effects of miR-148a on (P)RR expression. In line with our recent findings, reduced (P)RR expression resulted in decreased cellular LDL uptake, likely as a consequence of decreased LDLR protein abundance. Overexpressing the (P)RR prevented miR-148a-induced reduction in LDLR abundance and cellular LDL uptake. Our study supports a new concept that miR-148a is a regulator of (P)RR expression. By reducing (P)RR abundance, miR-148a decreases LDLR protein abundance and consequently cellular LDL uptake

The Effect of the Thioether-Bridged, Stabilized Angiotensin-(1–7) Analogue Cyclic Ang-(1–7) on Cardiac Remodeling and Endothelial Function in Rats with Myocardial Infarction

Modulation of renin-angiotensin system (RAS) by angiotensin-(1–7) (Ang-(1–7)) is an attractive approach to combat the detrimental consequences of myocardial infarction (MI). However Ang-(1–7) has limited clinical potential due to its unfavorable pharmacokinetic profile. We investigated effects of a stabilized, thioether-bridged analogue of Ang-(1–7) called cyclic Ang-(1–7) in rat model of myocardial infarction. Rats underwent coronary ligation or sham surgery. Two weeks thereafter infusion with 0.24 or 2.4 μg/kg/h cAng-(1–7) or saline was started for 8 weeks. Thereafter, cardiac morphometric and hemodynamic variables as wells as aortic endothelial function were measured. The average infarct size was 13.8% and was not changed by cAng-(1–7) treatment. MI increased heart weight and myocyte size, which was restored by cAng-(1–7) to sham levels. In addition, cAng-(1–7) lowered left ventricular end-diastolic pressure and improved endothelial function. The results suggest that cAng-(1–7) is a promising new agent in treatment of myocardial infarction and warrant further research