bims-hafaim Biomed News
on Heart failure metabolism
Issue of 2022–09–18
five papers selected by
Kyle McCommis, Saint Louis University



  1. Pharmacol Res. 2022 Sep 09. pii: S1043-6618(22)00393-0. [Epub ahead of print] 106448
      This study aimed at investigating the SGLT2 expression in human cardiomyocytes. Human studies evaluating cardiomyocyte SGLT2s expression are limited. To better clarify this issue, SGLT2 protein expression was assessed in human hearts of diabetic and non-diabetic patients, and in AC16 human cardiomyocyte cell line. A prospective study with a follow-up of patients who underwent their first heart transplant (HTX) was performed. Explanted heart, basal (1 week after HTX), and final (48 weeks after HTX) endomyocardial biopsies (EMBs) from patients were evaluated for SGLT2 occurrence in cardiomyocyte with immunohistochemistry, immunofluorescence and SGLT2 quantization with both real-time reverse transcription-polymerase chain reaction and Western blot analysis. The immunofluorescence co-localization of SGLT2 in cardiomyocyte evidenced that an increased expression in the explanted heart from diabetic patients compared to non-diabetic (p<0.001). In all final EMBs from diabetic patients, the expression of SGLT2 in cardiomyocyte was increased compared to non-diabetic (p<0.01). This evidence was confirmed by Western blot analysis of SGLT2 protein. In addition, PCR analysis revealed very low mRNA levels in basal EMBs from diabetic and non-diabetic patients (p=NS), whereas final EMBs from diabetic patients showed higher SGLT2 mRNA levels in diabetic compared to non-diabetic patients (p<0.05). Cultured human cardiomyocytes exposed to high-glucose showed increased expression of SGLT2 protein compared to cells exposed to normal glucose (p<0.05). The presence of SGLT2 in cardiomyocytes supports the hypothesis of SGLT2i-mediated impact on metabolic pathways within cardiomyocytes. Moreover, metabolic disorders linked to diabetes may lead promptly to upregulation of SGLT2 levels in human cardiomyocytes.
    Keywords:  Cardiomyocytes; Diabetes Mellitus; SGLT2; cardiovascular Disease
    DOI:  https://doi.org/10.1016/j.phrs.2022.106448
  2. Circulation. 2022 Sep 13. 101161CIRCULATIONAHA122059755
       BACKGROUND: Women and men with heart failure (HF) and preserved ejection fraction may differ in their clinical characteristics and their response to therapy. The aim of this study was to evaluate the influence of sex on the effects of empagliflozin in patients with HF and preserved ejection fraction enrolled in the EMPEROR-Preserved trial (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Preserved Ejection Fraction).
    METHODS: The effects of empagliflozin on the primary outcome of cardiovascular death or hospitalization for HF and on secondary outcomes (including total HF hospitalization, cardiovascular and all-cause mortality, and Kansas City Cardiomyopathy Questionnaire scores) were compared in women and men in the overall cohort and in subgroups defined by left ventricular ejection fraction (41%-49%, 50%-59%, and ≥60%). The effects of empagliflozin on physiological measures, including changes in systolic blood pressure, uric acid, hemoglobin, body weight, and natriuretic peptide levels, were also assessed.
    RESULTS: Of the 5988 patients randomized, 2676 (44.7%) were women. In the placebo arm, women tended to have lower risk for adverse outcomes, including a lower risk of all-cause mortality (hazard ratio, 0.69 [95% CI, 0.56, 0.84]). Compared with placebo, empagliflozin reduced the risk of cardiovascular death or hospitalization for HF to a similar degree in both sexes (hazard ratio, 0.81 [95% CI, 0.69, 0.96] for men; and hazard ratio, 0.75 [95% CI, 0.61, 0.92] for women; Pinteraction=0.54). Sex did not modify the relationship between empagliflozin and outcomes across ejection fraction groups. Similar results were seen for secondary outcomes and physiological measures. Compared with placebo, empagliflozin improved the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score to a similar extent in both sexes (1.38 for men versus 1.63 for women at 52 weeks; Pinteraction=0.77); the results were similar for Kansas City Cardiomyopathy Questionnaire overall summary score and total summary score.
    CONCLUSIONS: Empagliflozin produced similar benefits on outcomes and health status in women and men with HF and preserved ejection fraction.
    REGISTRATION: URL: https://www.
    CLINICALTRIALS: gov; Unique identifier: NCT03057951.
    Keywords:  empagliflozin; health status; heart failure; hospitalization; men; women
    DOI:  https://doi.org/10.1161/CIRCULATIONAHA.122.059755
  3. Cell Metab. 2022 Sep 08. pii: S1550-4131(22)00360-6. [Epub ahead of print]
      Cardiomyopathy and heart failure are common manifestations in mitochondrial disease caused by deficiencies in the oxidative phosphorylation (OXPHOS) system of mitochondria. Here, we demonstrate that the cardiac-specific loss of the assembly factor Cox10 of the cytochrome c oxidase causes mitochondrial cardiomyopathy in mice, which is associated with OXPHOS deficiency, lysosomal defects, and an aberrant mitochondrial morphology. Activation of the mitochondrial peptidase Oma1 in Cox10-/- mice results in mitochondrial fragmentation and induction of the integrated stress response (ISR) along the Oma1-Dele1-Atf4 signaling axis. Ablation of Oma1 or Dele1 in Cox10-/- mice aggravates cardiomyopathy. ISR inhibition impairs the cardiac glutathione metabolism, limits the selenium-dependent accumulation of the glutathione peroxidase Gpx4, and increases lipid peroxidation in the heart, ultimately culminating in ferroptosis. Our results demonstrate a protective role of the Oma1-Dele1-mediated ISR in mitochondrial cardiomyopathy and link ferroptosis to OXPHOS deficiency and mitochondrial disease.
    Keywords:  Atf4; Dele1; Gpx4; Oma1; cardiomyopathy; ferroptosis; glutathione; integrated stress response; mitochondria; selenium
    DOI:  https://doi.org/10.1016/j.cmet.2022.08.017
  4. Front Cardiovasc Med. 2022 ;9 945142
      The ATP consumption in heart is very intensive to support muscle contraction and relaxation. Mitochondrion is the power plant of the cell. Mitochondrial dysfunction has long been believed as the primary mechanism responsible for the inability of energy generation and utilization in heart failure. In addition, emerging evidence has demonstrated that mitochondrial dysfunction also contributes to calcium dysregulation, oxidative stress, proteotoxic insults and cardiomyocyte death. These elements interact with each other to form a vicious circle in failing heart. The role of mitochondrial dysfunction in the pathogenesis of heart failure has attracted increasing attention. The complex signaling of mitochondrial quality control provides multiple targets for maintaining mitochondrial function. Design of therapeutic strategies targeting mitochondrial dysfunction holds promise for the prevention and treatment of heart failure.
    Keywords:  calcium; fusion and fission; heart failure; mitochondria; mitophagy; reactive oxygen species
    DOI:  https://doi.org/10.3389/fcvm.2022.945142
  5. Circulation. 2022 Sep 13. 146(11): 819-821
      
    Keywords:  Editorials; clinical trial; heart failure; metabolism; metabolomics; pharmacology
    DOI:  https://doi.org/10.1161/CIRCULATIONAHA.122.060805