Dataset Information

Combined Inhibition of the Renin-Angiotensin System and Neprilysin Positively Influences Complex Mitochondrial Adaptations in Progressive Experimental Heart Failure.

ABSTRACT:

Background

Inhibitors of the renin angiotensin system and neprilysin (RAS-/NEP-inhibitors) proved to be extraordinarily beneficial in systolic heart failure. Furthermore, compelling evidence exists that impaired mitochondrial pathways are causatively involved in progressive left ventricular (LV) dysfunction. Consequently, we aimed to assess whether RAS-/NEP-inhibition can attenuate mitochondrial adaptations in experimental heart failure (HF).

Methods and results

By progressive right ventricular pacing, distinct HF stages were induced in 15 rabbits, and 6 animals served as controls (CTRL). Six animals with manifest HF (CHF) were treated with the RAS-/NEP-inhibitor omapatrilat. Echocardiographic studies and invasive blood pressure measurements were undertaken during HF progression. Mitochondria were isolated from LV tissue, respectively, and further worked up for proteomic analysis using the SWATH technique. Enzymatic activities of citrate synthase and the electron transfer chain (ETC) complexes I, II, and IV were assessed. Ultrastructural analyses were performed by transmission electron microscopy. During progression to overt HF, intricate expression changes were mainly detected for proteins belonging to the tricarboxylic acid cycle, glucose and fat metabolism, and the ETC complexes, even though ETC complex I, II, or IV enzymatic activities were not significantly influenced. Treatment with a RAS-/NEP-inhibitor then reversed some maladaptive metabolic adaptations, positively influenced the decline of citrate synthase activity, and altered the composition of each respiratory chain complex, even though this was again not accompanied by altered ETC complex enzymatic activities. Finally, ultrastructural evidence pointed to a reduction of autophagolytic and degenerative processes with omapatrilat-treatment.

Conclusions

This study describes complex adaptations of the mitochondrial proteome in experimental tachycardia-induced heart failure and shows that a combined RAS-/NEP-inhibition can beneficially influence mitochondrial key pathways.

SUBMITTER: Grois L

PROVIDER: S-EPMC5226780 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

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Publications

Combined Inhibition of the Renin-Angiotensin System and Neprilysin Positively Influences Complex Mitochondrial Adaptations in Progressive Experimental Heart Failure.

Grois Laura L Hupf Julian J Reinders Jörg J Schröder Josef J Dietl Alexander A Schmid Peter M PM Jungbauer Carsten C Resch Markus M Maier Lars S LS Luchner Andreas A Birner Christoph C

PloS one 20170111 1

<h4>Background</h4>Inhibitors of the renin angiotensin system and neprilysin (RAS-/NEP-inhibitors) proved to be extraordinarily beneficial in systolic heart failure. Furthermore, compelling evidence exists that impaired mitochondrial pathways are causatively involved in progressive left ventricular (LV) dysfunction. Consequently, we aimed to assess whether RAS-/NEP-inhibition can attenuate mitochondrial adaptations in experimental heart failure (HF).<h4>Methods and results</h4>By progressive rig ...[more]

PMID: 28076404

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Project description:BACKGROUND:There is a paucity of data about the mechanisms by which sacubitril/valsartan (also known as LCZ696) improves outcomes in patients with heart failure. Specifically, the effects of sacubitril/valsartan on vascular function and NO bioavailability have not been investigated. We hypothesized that sacubitril/valsartan therapy increases circulating NO levels and improves vascular function in the setting of heart failure. METHODS AND RESULTS:Male spontaneously hypertensive rats underwent myocardial ischemia/reperfusion surgery to induce heart failure and were followed for up to 12 weeks with serial echocardiography. Rats received sacubitril/valsartan (68 mg/kg), valsartan (31 mg/kg), or vehicle starting at 4 weeks after reperfusion. At 8 or 12 weeks of reperfusion, animals were euthanized and tissues were collected for ex vivo analyses of NO bioavailability, aortic vascular reactivity, myocardial and vascular histology, and cardiac molecular assays. Left ventricular structure and function were improved by both valsartan and sacubitril/valsartan compared with vehicle. Sacubitril/valsartan resulted in superior cardiovascular benefits, as evidenced by sustained improvements in left ventricular ejection fraction and end-diastolic pressure. Ex vivo vascular function, as measured by aortic vasorelaxation responses to acetylcholine and sodium nitroprusside, was significantly improved by valsartan and sacubitril/valsartan, with more sustained improvements afforded by sacubitril/valsartan. Furthermore, myocardial NO bioavailability was significantly enhanced in animals receiving sacubitril/valsartan therapy. CONCLUSIONS:Sacubitril/valsartan offers superior cardiovascular protection in heart failure and improves vascular function to a greater extent than valsartan alone. Sacubitril/valsartan-mediated improvements in cardiac and vascular function are likely related to increases in NO bioavailability and explain, in part, the benefits beyond angiotensin receptor blockade.

Project description:Aims: We aim to perform a systematic review and meta-analysis examining randomized controlled trials assessing the efficacy and safety of sacubitril/valsartan in patients on renal outcomes, in comparison with the renin-angiotensin-aldosterone system inhibitor (RAASi). Methods: Eligible studies were retrieved on MEDLINE, EMBASE, and Cochrane until September 2021. The primary outcome was the incidence of renal impairment, which was defined as the composite of increases in serum creatinine by >0.3 mg/dl and/or a reduction in eGFR ≥25%, development of ESRD, or renal death. We pooled relative risks (RRs) with 95% confidence intervals (CIs) or the mean difference with 95% CIs for the variables. Results: Our search yielded 10 randomized controlled trials with a total of 18,362 patients. Compared with RAASi treatment, patients treated with sacubitril/valsartan had lower incidence of composite renal impairment (10 studies, 18,362 patients, RR 0.84; 95% CI 0.72-0.96, p = 0.01; I 2 = 22%), ESRD development (3 studies, 13,609 patients, RR 0.53; 95% CI 0.30-0.96, p = 0.03; I 2 = 0%), drug discontinuation due to renal events (4 studies, 9,995 patients, RR 0.58; 95% CI 0.40-0.83, p = 0.003; I 2 = 47%), severe hyperkalemia (6 studies, 16,653 patients, RR 0.80; 95% CI 0.68-0.93, p = 0.01; I 2 = 25%) and a slower eGFR decline (4 studies, 13,608 patients, WMD 0.56; 95% CI 0.36-0.76, p < 0.00001; I 2 = 65%). Subgroup analysis demonstrated that sacubitril/valsartan was associated with a lower incidence of renal impairment in patients with heart failure and preserved ejection fraction (HFpEF), but not in those with heart failure and reduced ejection fraction (HFrEF). The superior renal function preservation of sacubitril/valsartan treatment was not associated with different baseline eGFR levels and follow-up duration. There was a smaller increase in the change in the urine albumin-to-creatinine ratio (UACR) (3 studies, 9,114 patients, SMD 0.06; 95% CI 0.02-0.10, p = 0.003; I 2 = 14%) with sacubitril/valsartan treatment. However, patients with heart failure appeared to have increased microalbuminuria, not patients without HF (p = 0.80 for interaction). Conclusion: Sacubitril/valsartan was associated with a lower incidence of composite renal impairment especially in patients with HFpEF, but higher microalbuminuria in patients with heart failure (both HFrEF and HFpEF) compared with RAASi. The lower incidence of severe hyperkalemia and drug discontinuation due to renal events in patients with sacubitril/valsartan treatment demonstrated its superior safety compared with RAASi.

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Dataset Information

Combined Inhibition of the Renin-Angiotensin System and Neprilysin Positively Influences Complex Mitochondrial Adaptations in Progressive Experimental Heart Failure.

Background

Methods and results

Conclusions

Publications

Combined Inhibition of the Renin-Angiotensin System and Neprilysin Positively Influences Complex Mitochondrial Adaptations in Progressive Experimental Heart Failure.

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