bims-hafaim 2022-10-02 papers

Issue of 2022–10–02
five papers selected by
Kyle McCommis, Saint Louis University

J Am Heart Assoc. 2022 Sep 29. e026728

Long-Term Activation of Glucagon-like peptide-1 receptor by Dulaglutide Prevents Diabetic Heart Failure and Metabolic Remodeling in Type 2 Diabetes.

Saiyang Xie, Min Zhang, Wenke Shi, Yun Xing, Yan Huang, Wen-Xi Fang, Shi-Qiang Liu, Meng-Ya Chen, Tong Zhang, Si Chen, Xiaofeng Zeng, Shasha Wang, Wei Deng, Qizhu Tang.

Background Mechanistic insights of glucagon-like peptide-1 receptor agonists remain incompletely identified, despite the efficacy in heart failure observed in clinical trials. Here, we evaluated the effects of dulaglutide on heart complications and illuminated its underlying mechanism. Methods and Results We used mice with high-fat diet (HFD)/streptozotocin-induced type 2 diabetes to investigate the effects of dulaglutide upon diabetic cardiac dysfunction. After the onset of diabetes, control and diabetic mice were injected subcutaneously with either dulaglutide (type 2 diabetes-dulaglutide and control-dulaglutide groups) or vehicle (type 2 diabetes-vehicle and control-vehicle groups) for 8 weeks. Subsequently, heart characteristics, cardiometabolic profile and mitochondrial morphology and function were evaluated. Also, we analyzed the effects of dulaglutide on neonatal rat ventricular myocytes treated with high glucose plus palmitic acid. In addition, wild type and AMP-activated protein kinase α2 mutant mice were used to evaluate the underlying mechanism. In type 2 diabetes mouse model, dulaglutide ameliorated insulin resistance, improved glucose tolerance, reduced hyperlipidemia, and promoted fatty acid use in the myocardium. Dulaglutide treatment functionally attenuated cardiac remodeling and dysfunction and promoted metabolic reprogramming in diabetic mice. Furthermore, dulaglutide improved mitochondria fragmentation in myocytes, and simultaneously reinstated mitochondrial morphology and function in diabetic hearts. We also found that dulaglutide preserved AMP-activated protein kinase α2-dependent mitochondrial homeostasis, and the protective effects of dulaglutide on diabetic heart was almost abated by AMP-activated protein kinase α2 knockout. Conclusions Dulaglutide prevents diabetic heart failure and favorably affects myocardial metabolic remodeling by impeding mitochondria fragmentation, and we suggest a potential strategy to develop a long-term activation of glucagon-like peptide-1 receptor-based therapy to treat diabetes associated cardiovascular complications.

Keywords: dulaglutide; heart failure; metabolic remodeling; mitochondria; type 2 diabetes

DOI: https://doi.org/10.1161/JAHA.122.026728

J Cell Mol Med. 2022 Sep 25.

Mitochondrial derived peptide MOTS-c prevents the development of heart failure under pressure overload conditions in mice.

Peng Zhong, Jianye Peng, Yewen Hu, Jun Zhang, Caijie Shen.

MOTS-c, a mitochondrial-derived peptide (MDP), has been shown to have multiple biological activities such as antioxidation, anti-inflammation, and anti-apoptosis properties. In the present study, we aimed at evaluating the therapeutic effect of MOTS-c peptide in an animal model of heart failure. The heart failure mouse model was made by transverse aortic constriction (TAC) operations. The MOTS-c peptide was administrated subcutaneously by using an osmotic pump. At the end of the animal experiment, cardiac function was evaluated by echocardiography, and heart tissues were subjected to histological and molecular analysis. In vitro cultured H9C2 cells were used to test the effects of MOTS-c overexpression on cell death in response to H2 O2 stimulation. Our study showed that MOTS-c peptide attenuated TAC-induced cardiac dysfunction and remodelling. In addition, the MOTS-c peptide reduced the inflammatory response and upregulated the antioxidant capacity, coupled with the activation of the AMPK pathway in the heart of the TAC mouse model. In in vitro cultured cardiac cells, overexpression of MOTS-c was shown to activate the AMPK pathway and protect cell apoptosis in response to H2 O2 stimulation. Taken together, our study suggested that MOTS-c peptides may have therapeutic potential in treating HF.

Keywords: MOTS-c; heart failure; inflammation; oxidative stress; pressure overload

DOI: https://doi.org/10.1111/jcmm.17551

Arch Med Sci Atheroscler Dis. 2021 ;6 e209-e214

Ketone bodies and the heart.

Athanasia K Papazafiropoulou, Maximos M Georgopoulos, Nikolaos L Katsilambros.

Ketone bodies are low chain organic substances with four carbon atoms, with β-hydroxybutyric acid and acetone being the main ketone bodies in blood circulation. Under physiological conditions their levels are low while during conditions of oxidative stress, such as exercise, fasting state and acute illness, ketone body levels are increased. Recent findings have shown that in patients with heart failure their plasma concentration is increased. There is a positive correlation between increased energy metabolism of myocardial cells and the levels of β-hydroxybutyric acid and acetone. Furthermore, it has been hypothesized that the mild ketosis caused by sodium glucose cotransporter 2 inhibitors is one of the possible pathogenetic mechanisms explaining the significant cardiovascular and renal benefits observed in patients with type 2 diabetes treated with these agents. The aim of the present review is to summarize the role of ketone bodies in both normal and pathological conditions, such as heart failure.

Keywords: diabetes mellitus; heart failure; ketogenic diet; ketone bodies; β-hydroxybutyric acid

DOI: https://doi.org/10.5114/amsad.2021.112475

Life Sci. 2022 Sep 27. pii: S0024-3205(22)00698-1. [Epub ahead of print] 120998

Acetylation and phosphorylation changes to cardiac proteins in experimental HFpEF due to metabolic risk reveal targets for treatment.

Franziska Koser, Anastasia J Hobbach, Mahmoud Abdellatif, Viktoria Herbst, Clara Türk, Holger Reinecke, Marcus Krüger, Simon Sedej, Wolfgang A Linke.

AIMS: Despite the high prevalence of heart failure with preserved ejection fraction (HFpEF), the pathomechanisms remain elusive and specific therapy is lacking. Disease-causing factors include metabolic risk, notably obesity. However, proteomic changes in HFpEF are poorly understood, hampering therapeutic strategies. We sought to elucidate how metabolic syndrome affects cardiac protein expression, phosphorylation and acetylation in the Zucker diabetic fatty/Spontaneously hypertensive heart failure F1 (ZSF1) rat HFpEF model, and to evaluate changes regarding their potential for treatment.
MAIN METHODS: ZSF1 obese and lean rats were fed a Purina diet up to the onset of HFpEF in the obese animals. We quantified the proteome, phosphoproteome and acetylome of ZSF1 obese versus lean heart tissues by mass spectrometry and singled out targets for site-specific evaluation.
KEY FINDINGS: The acetylome of ZSF1 obese versus lean hearts was more severely altered (21 % of proteins changed) than the phosphoproteome (9 %) or proteome (3 %). Proteomic alterations, confirmed by immunoblotting, indicated low-grade systemic inflammation and endothelial remodeling in obese hearts, but low nitric oxide-dependent oxidative/nitrosative stress. Altered acetylation in ZSF1 obese hearts mainly affected pathways important for metabolism, energy production and mechanical function, including hypo-acetylation of mechanical proteins but hyper-acetylation of proteins regulating fatty acid metabolism. Hypo-acetylation and hypo-phosphorylation of elastic titin in ZSF1 obese hearts could explain myocardial stiffening.
SIGNIFICANCE: Cardiometabolic syndrome alters posttranslational modifications, notably acetylation, in experimental HFpEF. Pathway changes implicate a HFpEF signature of low-grade inflammation, endothelial dysfunction, metabolic and mechanical impairment, and suggest titin stiffness and mitochondrial metabolism as promising therapeutic targets.

Keywords: Diastolic dysfunction; Meta-inflammation; Myocardial stiffness; Obesity; Proteomics

DOI: https://doi.org/10.1016/j.lfs.2022.120998

ESC Heart Fail. 2022 Sep 30.

Homoarginine and creatine deficiency do not exacerbate murine ischaemic heart failure.

Debra J McAndrew, Hannah A Lake, Sevasti Zervou, Edzard Schwedhelm, Jurgen E Schneider, Stefan Neubauer, Craig A Lygate.

AIMS: Low levels of homoarginine and creatine are associated with heart failure severity in humans, but it is unclear to what extent they contribute to pathophysiology. Both are synthesized via L-arginine:glycine amidinotransferase (AGAT), such that AGAT-/- mice have a combined creatine and homoarginine deficiency. We hypothesized that this would be detrimental in the setting of chronic heart failure.
METHODS AND RESULTS: Study 1: homoarginine deficiency-female AGAT-/- and wild-type mice were given creatine-supplemented diet so that both had normal myocardial creatine levels, but only AGAT-/- had low plasma homoarginine. Myocardial infarction (MI) was surgically induced and left ventricular (LV) structure and function assessed at 6-7 weeks by in vivo imaging and haemodynamics. Study 2: homoarginine and creatine-deficiency-as before, but AGAT-/- mice were given creatine-supplemented diet until 1 week post-MI, when 50% were changed to a creatine-free diet. Both groups therefore had low homoarginine levels, but one group also developed lower myocardial creatine levels. In both studies, all groups had LV remodelling and dysfunction commensurate with the development of chronic heart failure, for example, LV dilatation and mean ejection fraction <20%. However, neither homoarginine deficiency alone or in combination with creatine deficiency had a significant effect on mortality, LV remodelling, or on any indices of contractile and lusitropic function.
CONCLUSIONS: Low levels of homoarginine and creatine do not worsen chronic heart failure arguing against a major causative role in disease progression. This suggests that it is unnecessary to correct hArg deficiency in patients with heart failure, although supra-physiological levels may still be beneficial.

Keywords: Animal models; Creatine; Heart failure; Homoarginine; Myocardial infarction; Ventricular function

DOI: https://doi.org/10.1002/ehf2.14183