In vivo overexpression of frataxin causes toxicity mediated by iron-sulfur cluster deficiency

Autor: Claudia Huichalaf, Tyler L. Perfitt, Anna Kuperman, Renea Gooch, Ramesh C. Kovi, Karrie A. Brenneman, Xian Chen, Dinesh Hirenallur-Shanthappa, Tiffany Ma, Basel T. Assaf, Ingrid Pardo, Tania Franks, Laura Monarski, Ting-Wen Cheng, Kevin Le, Chunyan Su, Suryanarayan Somanathan, Laurence O. Whiteley, Christine Bulawa, Marko J. Pregel, Alain Martelli
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Molecular Therapy: Methods & Clinical Development, Vol 24, Iss , Pp 367-378 (2022)
Druh dokumentu: article
ISSN: 2329-0501
DOI: 10.1016/j.omtm.2022.02.002
Popis: Friedreich's ataxia is a rare disorder resulting from deficiency of frataxin, a mitochondrial protein implicated in the synthesis of iron-sulfur clusters. Preclinical studies in mice have shown that gene therapy is a promising approach to treat individuals with Friedreich's ataxia. However, a recent report provided evidence that AAVrh10-mediated overexpression of frataxin could lead to cardiotoxicity associated with mitochondrial dysfunction. While evaluating an AAV9-based frataxin gene therapy using a chicken β-actin promoter, we showed that toxic overexpression of frataxin could be reached in mouse liver and heart with doses between 1 × 1013 and 1 × 1014 vg/kg. In a mouse model of cardiac disease, these doses only corrected cardiac dysfunction partially and transiently and led to adverse findings associated with iron-sulfur cluster deficiency in liver. We demonstrated that toxicity required frataxin's primary function by using a frataxin construct bearing the N146K mutation, which impairs binding to the iron-sulfur cluster core complex. At the lowest tested dose, we observed moderate liver toxicity that was accompanied by progressive loss of transgene expression and liver regeneration. Together, our data provide insights into the toxicity of frataxin overexpression that should be considered in the development of a gene therapy approach for Friedreich's ataxia.
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