| First Author | Hsiao YT | Year | 2021 |
| Journal | Sci Rep | Volume | 11 |
| Issue | 1 | Pages | 6722 |
| PubMed ID | 33762690 | Mgi Jnum | J:304959 |
| Mgi Id | MGI:6695608 | Doi | 10.1038/s41598-021-86209-y |
| Citation | Hsiao YT, et al. (2021) Cardiac mitofusin-1 is reduced in non-responding patients with idiopathic dilated cardiomyopathy. Sci Rep 11(1):6722 |
| abstractText | Prognosis of severe heart failure remains poor. Urgent new therapies are required. Some heart failure patients do not respond to established multidisciplinary treatment and are classified as "non-responders". The outcome is especially poor for non-responders, and underlying mechanisms are largely unknown. Mitofusin-1 (Mfn1), a mitochondrial fusion protein, is significantly reduced in non-responding patients. This study aimed to elucidate the role of Mfn1 in the failing heart. Twenty-two idiopathic dilated cardiomyopathy (IDCM) patients who underwent endomyocardial biopsy of intraventricular septum were included. Of the 22 patients, 8 were non-responders (left ventricular (LV) ejection fraction (LVEF) of < 10% improvement at late phase follow-up). Electron microscopy (EM), quantitative PCR, and immunofluorescence studies were performed to explore the biological processes and molecules involved in failure to respond. Studies in cardiac specific Mfn1 knockout mice (c-Mfn1 KO), and in vitro studies with neonatal rat ventricular myocytes (NRVMs) were also conducted. A significant reduction in mitochondrial size in cardiomyocytes, and Mfn1, was observed in non-responders. A LV pressure overload with thoracic aortic constriction (TAC) c-Mfn1 KO mouse model was generated. Systolic function was reduced in c-Mfn1 KO mice, while mitochondria alteration in TAC c-Mfn1 KO mice increased. In vitro studies in NRVMs indicated negative regulation of Mfn1 by the beta-AR/cAMP/PKA/miR-140-5p pathway resulting in significant reduction in mitochondrial respiration of NRVMs. The level of miR140-5p was increased in cardiac tissues of non-responders. Mfn1 is a biomarker of heart failure in non-responders. Therapies targeting mitochondrial dynamics and homeostasis are next generation therapy for non-responding heart failure patients. |
