Treatment of dilated cardiomyopathy in a mouse model of Friedreich’s ataxia using N-acetylcysteine and identification of alterations in microRNA expression that could be involved in its pathogenesis

• Published in: Pharmacological research 2020-09, Vol.159, p.104994-104994, Article 104994
• Main Authors: Chiang, S., Huang, M.L.H., Richardson, D.R.
• Format: Article
• Language: English
• Subjects: Acetylcysteine - pharmacology; Animals; Antioxidants; Basic-Leucine Zipper Transcription Factors - metabolism; Cardiomyopathy; Cardiomyopathy, Dilated - drug therapy; Cardiomyopathy, Dilated - etiology; Cardiomyopathy, Dilated - genetics; Cardiomyopathy, Dilated - metabolism; Cell Line, Tumor; Disease Models, Animal; Frataxin; Friedreich Ataxia - complications; Friedreich Ataxia - genetics; Gene Expression Regulation; Humans; Iron; Iron-Binding Proteins - genetics; Iron-Binding Proteins - metabolism; Isothiocyanates - pharmacology; Kelch-Like ECH-Associated Protein 1 - metabolism; Mice, Knockout; MicroRNAs - genetics; MicroRNAs - metabolism; Myocytes, Cardiac - drug effects; Myocytes, Cardiac - metabolism; Myocytes, Cardiac - pathology; N-acetylcysteine; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; Sulfoxides - pharmacology
• ISSN: 1043-6618; 1096-1186
• DOI: 10.1016/j.phrs.2020.104994

[Display omitted] •N-acetylcysteine (NAC) attenuated sulforaphane induced NRF2, KEAP1 and BACH1.•NAC given to MCK frataxin knockout (MCK KO) mice demonstrated less body weight loss.•NAC did not rescue the cardiomyopathy in the MCK KO mice.•In MCK KO mice, microRNA-144 (miR-144) was up-regulated, which down-regulates Nrf2.•The screening of miRNA in MCK KO mice showed 23 miRNAs from 756 screened were altered. Deficient expression of the mitochondrial protein, frataxin, leads to a deadly cardiomyopathy. Our laboratory reported the master regulator of oxidative stress, nuclear factor erythroid 2-related factor-2 (Nrf2), demonstrates marked down-regulation after frataxin deletion in the heart. This was due, in part, to a pronounced increase in Keap1. To assess if this can be therapeutically targeted, cells were incubated with N-acetylcysteine (NAC), or buthionine sulfoximine (BSO), which increases or decreases glutathione (GSH), respectively, or the NRF2-inducer, sulforaphane (SFN). While SFN significantly (p < 0.05) induced NRF2, KEAP1 and BACH1, NAC attenuated SFN-induced NRF2, KEAP1 and BACH1. The down-regulation of KEAP1 by NAC was of interest, as Keap1 is markedly increased in the MCK conditional frataxin knockout (MCK KO) mouse model and this could lead to the decreased Nrf2 levels. Considering this, MCK KO mice were treated with i.p. NAC (500- or 1500-mg/kg, 5 days/week for 5-weeks) and demonstrated slightly less (p > 0.05) body weight loss versus the vehicle-treated KO. However, NAC did not rescue the cardiomyopathy. To additionally examine the dys-regulation of Nrf2 upon frataxin deletion, studies assessed the role of microRNA (miRNA) in this process. In MCK KO mice, miR-144 was up-regulated, which down-regulates Nrf2. Furthermore, miRNA screening in MCK KO mice demonstrated 23 miRNAs from 756 screened were significantly (p < 0.05) altered in KOs versus WT littermates. Of these, miR-21*, miR-34c*, and miR-200c, demonstrated marked alterations, with functional clustering analysis showing they regulate genes linked to cardiac hypertrophy, cardiomyopathy, and oxidative stress, respectively.