bims-hafaim Biomed News
on Heart failure metabolism
Issue of 2022–07–24
six papers selected by
Kyle McCommis, Saint Louis University



  1. Sci Rep. 2022 Jul 18. 12(1): 12258
      Heart failure (HF) is the inability of the heart to pump blood sufficiently to meet the metabolic demands of the body. HF with reduced systolic function is characterized by cardiac hypertrophy, ventricular fibrosis and remodeling, and decreased cardiac contractility, leading to cardiac functional impairment and death. Transverse aortic constriction (TAC) is a well-established model for inducing hypertrophy and HF in rodents. Mice globally deficient in sirtuin 5 (SIRT5), a NAD+-dependent deacylase, are hypersensitive to cardiac stress and display increased mortality after TAC. Prior studies assessing SIRT5 functions in the heart have all employed loss-of-function approaches. In this study, we generated SIRT5 overexpressing (SIRT5OE) mice, and evaluated their response to chronic pressure overload using TAC. Compared to littermate controls, SIRT5OE mice were protected against adverse functional consequences of TAC, left ventricular dilation and impaired ejection fraction. Transcriptomic analysis revealed that SIRT5 suppresses key HF sequelae, including the metabolic switch from fatty acid oxidation to glycolysis, immune activation, and fibrotic signaling pathways. We conclude that SIRT5 is a limiting factor in the preservation of cardiac function in response to experimental pressure overload.
    DOI:  https://doi.org/10.1038/s41598-022-16506-7
  2. J Cell Mol Med. 2022 Jul 20.
      Adrenergic stimulation in the heart activates the protein kinase A (PKA), which phosphorylates key proteins involved in intracellular Ca2+ handling. PKA is held in proximity to its substrates by protein scaffolds, the A kinase anchoring proteins (AKAPs). We have previously identified the transcript of phosphodiesterase 4D interacting protein (Pde4dip; also known as myomegalin), one of the sarcomeric AKAPs, as being differentially expressed following hemodynamic overload, a condition inducing hyperadrenergic state in the heart. Here, we addressed whether PDE4DIP is involved in the adverse cardiac remodelling following hemodynamic stress. Homozygous Pde4dip knockout (KO) mice, generated by CRISPR-Cas9 technology, and wild-type (WT) littermates were exposed to aortocaval shunt (shunt) or transthoracic aortic constriction (TAC) to induce hemodynamic volume overload (VO) or pressure overload (PO), respectively. The mortality, cardiac structure, function and pathological cardiac remodelling were followed up after hemodynamic injuries. The PDE4DIP protein level was markedly downregulated in volume-overloaded- but upregulated in pressure-overloaded-WT hearts. Following shunt or TAC, mortality rates were comparably increased in both genotypes. Twelve weeks after shunt or TAC, Pde4dip-KO animals showed a similar degree of cardiac hypertrophy, dilatation and dysfunction as WT mice. Cardiomyocyte hypertrophy, myocardial fibrosis, reactivation of cardiac stress genes and downregulation of ATPase, Ca2+ transporting, cardiac muscle, slow twitch 2 transcript did not differ between WT and Pde4dip-KO hearts following shunt or TAC. In summary, despite a differential expression of PDE4DIP protein in remodelled WT hearts, Pde4dip deficiency does not modulate adverse cardiac remodelling after hemodynamic VO or PO.
    Keywords:  PKA compartmentalization; cardiac remodelling; pressure overload; volume overload
    DOI:  https://doi.org/10.1111/jcmm.17468
  3. J Am Heart Assoc. 2022 Jul 19. 11(14): e025310
      Background We showed that Beclin-1-dependent autophagy protects the heart in young and adult mice that underwent endotoxemia. Herein, we compared the potential therapeutic effects of Beclin-1 activating peptide, TB-peptide, on endotoxemia-induced cardiac outcomes in young adult and aged mice. We further evaluated lipopolysaccharide (lipopolysaccharide)-induced and TB-peptide treatment-mediated alterations in myocardial metabolism. Methods and Results C57BL/6J mice that were 10 weeks and 24 months old were challenged by lipopolysaccharide using doses at which cardiac dysfunction occurred. Following the treatment of TB-peptide or control vehicle, heart contractility, circulating cytokines, and myocardial autophagy were evaluated. We detected that TB-peptide boosted autophagy, attenuated cytokines, and improved cardiac performance in both young and aged mice during endotoxemia. A targeted metabolomics assay was designed to detect a pool of 361 known metabolites, of which 156 were detected in at least 1 of the heart tissue samples. Lipopolysaccharide-induced impairments were found in glucose and amino acid metabolisms in mice of all ages, and TB-peptide ameliorated these alterations. However, lipid metabolites were upregulated in the young group but moderately downregulated in the aged by lipopolysaccharide, suggesting an age-dependent response. TB-peptide mitigated lipopolysaccharide-mediated trend of lipids in the young mice but had little effect on the aged. (Study registration: Project DOI: https://doi.org/10.21228/M8K11W). Conclusions Pharmacological activation of Beclin-1 by TB-peptide is cardiac protective in both young and aged population during endotoxemia, suggest a therapeutic potential for sepsis-induced cardiomyopathy. Metabolomics analysis suggests that an age-independent protection by TB-peptide is associated with reprograming of energy production via glucose and amino acid metabolisms.
    Keywords:  Beclin‐1; autophagy; cardiac function; cardiac metabolism; endotoxemia; sepsis
    DOI:  https://doi.org/10.1161/JAHA.122.025310
  4. Front Immunol. 2022 ;13 919038
      Cardiac dysfunction is manifested as decline of cardiac systolic function, and multiple cardiovascular diseases (CVDs) can develop cardiac insufficiency. Mitochondrial antiviral signaling (MAVS) is known as an innate immune regulator involved in viral infectious diseases and autoimmune diseases, whereas its role in the heart remains obscure. The alteration of MAVS was analyzed in animal models with non-hypertrophic and hypertrophic cardiac dysfunction. Then, MAVS-deficient mice were generated to examine the heart function, mitochondrial status and energy metabolism. In vitro, CRISPR/Cas9-based gene editing was used to delete MAVS in H9C2 cell lines and the phenotypes of mitochondria and energy metabolism were evaluated. Here we observed reduced MAVS expression in cardiac tissue from several non-hypertrophic cardiac dysfunction models, contrasting to the enhanced MAVS in hypertrophic heart. Furthermore, we examined the heart function in mice with partial or total MAVS deficiency and found spontaneously developed cardiac pump dysfunction and cardiac dilation as assessed by echocardiography parameters. Metabonomic results suggested MAVS deletion probably promoted cardiac dysfunction by disturbing energy metabolism, especially lipid metabolism. Disordered and mitochondrial homeostasis induced by mitochondrial oxidative stress and mitophagy impairment also advanced the progression of cardiac dysfunction of mice without MAVS. Knockout of MAVS using CRISPR/Cas9 in cardiomyocytes damaged mitochondrial structure and function, as well as increased mitochondrial ROS production. Therefore, reduced MAVS contributed to the pathogenesis of non-hypertrophic cardiac dysfunction, which reveals a link between a key regulator of immunity (MAVS) and heart function.
    Keywords:  MAVS; cardiac dysfunction; energy metabolism; mitochondrial dysfunction; oxidative stress
    DOI:  https://doi.org/10.3389/fimmu.2022.919038
  5. Front Cardiovasc Med. 2022 ;9 924787
      Metabolic syndrome is a condition characterized by a clustering of metabolic abnormalities associated with an increased risk of type 2 diabetes and cardiovascular disease. An impaired insulin-stimulated myocardial glucose metabolism has been shown to be a risk factor for the development of cardiovascular disease in patients with type 2 diabetes. Whether cardiac insulin resistance occurs in subjects with metabolic syndrome remains uncertain. To investigate this issue, we evaluated myocardial glucose metabolic rate using cardiac dynamic 18F-FDG-PET combined with euglycemic-hyperinsulinemic clamp in three groups: a group of normal glucose tolerant individuals without metabolic syndrome (n = 10), a group of individuals with type 2 diabetes and metabolic syndrome (n = 19), and a group of subjects with type 2 diabetes without metabolic syndrome (n = 6). After adjusting for age and gender, individuals with type 2 diabetes and metabolic syndrome exhibited a significant reduction in insulin-stimulated myocardial glucose metabolic rate (10.5 ± 9.04 μmol/min/100 g) as compared with both control subjects (32.9 ± 9.7 μmol/min/100 g; P < 0.0001) and subjects with type 2 diabetes without metabolic syndrome (25.15 ± 4.92 μmol/min/100 g; P = 0.01). Conversely, as compared with control subjects (13.01 ± 8.53 mg/min x Kg FFM), both diabetic individuals with metabolic syndrome (3.06 ± 1.7 mg/min × Kg FFM, P = 0.008) and those without metabolic syndrome (2.91 ± 1.54 mg/min × Kg FFM, P = 0.01) exhibited a significant reduction in whole-body insulin-stimulated glucose disposal, while no difference was observed between the 2 groups of subjects with type 2 diabetes with or without metabolic syndrome. Univariate correlations showed that myocardial glucose metabolism was positively correlated with insulin-stimulated glucose disposal (r = 0.488, P = 0.003), and negatively correlated with the presence of metabolic syndrome (r = -0.743, P < 0.0001) and with its individual components. In conclusion, our data suggest that an impaired myocardial glucose metabolism may represent an early cardio-metabolic defect in individuals with the coexistence of type 2 diabetes and metabolic syndrome, regardless of whole-body insulin resistance.
    Keywords:  cardiac 18F-FDG-PET; cardiovascular disease; insulin resistance; metabolic syndrome; myocardial glucose metabolism; type 2 diabetes
    DOI:  https://doi.org/10.3389/fcvm.2022.924787
  6. Cell Death Dis. 2022 Jul 18. 13(7): 621
      Pathological cardiac hypertrophy is an independent risk factor for heart failure and is considered a target for the treatment of heart failure. However, the mechanisms underlying pathological cardiac hypertrophy remain largely unknown. We aimed to investigate the role of angiopoietin-like protein 8 (ANGPTL8) in pathological cardiac hypertrophy. We found that serum ANGPTL8 levels were significantly increased in hypertensive patients with cardiac hypertrophy and in mice with cardiac hypertrophy induced by Ang II or TAC. Furthermore, the secretion of ANGPTL8 from the liver was increased during hypertrophic processes, which were triggered by Ang II. In the Ang II- and transverse aortic constriction (TAC)-induced mouse cardiac hypertrophy model, ANGPTL8 deficiency remarkably accelerated cardiac hypertrophy and fibrosis with deteriorating cardiac dysfunction. Accordingly, both recombinant human full-length ANGPTL8 (rANGPTL8) protein and ANGPTL8 overexpression significantly mitigated Ang II-induced cell enlargement in primary neonatal rat cardiomyocytes (NRCMs) and H9c2 cells. Mechanistically, the antihypertrophic effects of ANGPTL8 depended on inhibiting Akt and GSK-3β activation, and the Akt activator SC-79 abolished the antihypertrophic effects of rANGPTL8 in vitro. Moreover, we demonstrated that ANGPTL8 directly bound to the paired Ig-like receptor PIRB (LILRB3) by RNA-seq and immunoprecipitation-mass screening. Remarkably, the antihypertrophic effects of ANGPTL8 were largely blocked by anti-LILRB3 and siRNA-LILRB3. Our study indicated that ANGPTL8 served as a novel negative regulator of pathological cardiac hypertrophy by binding to LILRB3 (PIRB) and inhibiting Akt/GSK3β activation, suggesting that ANGPTL8 may provide synergistic effects in combination with AT1 blockers and become a therapeutic target for cardiac hypertrophy and heart failure.
    DOI:  https://doi.org/10.1038/s41419-022-05029-8