Partial bypass of frataxin deficiency by ISCU M141I restores cytosolic and nuclear Fe–S cluster assembly

Mosbach, V., Maio, N., Hermet, L. et al. Partial bypass of frataxin deficiency by ISCU M141I restores cytosolic and nuclear Fe–S cluster assembly. Cell Death Differ (2026). doi:10.1038/s41418-026-01832-4  

Results reveal a previously unrecognized compartment-specific rescue of Fe-S cluster dependent processes by the ISCU M141I variant in mammalian cells, raising for the first time the possibility of compartmental regulation of Fe-S cluster biogenesis.

Autophagy activation by urolithin-a derivative UA-36 mitigates Friedreich's ataxia pathologies induced by frataxin deficiency

Gong Q, Liu T, Han X, Zhang R, Liu X, Xiong B, Ali T, Huang J, Xie Y, Li S, Yang X. Autophagy activation by urolithin-a derivative UA-36 mitigates Friedreich's ataxia pathologies induced by frataxin deficiency. Mol Biomed. 2026 Jun 4;7(1):82. doi: 10.1186/s43556-026-00457-w. PMID: 42240896; PMCID: PMC13237351. 

 Here, we investigate the therapeutic efficacy and underlying mechanisms of UA-36, a novel water-soluble and bioavailable derivative of urolithin A, in cellular and animal models of FA. In Fxn-knockdown N2a cells, UA-36 significantly restored FXN protein levels, enhanced autophagic flux, improved mitochondrial function, and attenuated oxidative stress–induced damage. In vivo, oral administration of UA-36 for eight weeks in YG8R transgenic mice, a well-established FA model, markedly improved motor coordination, gait performance, and skeletal muscle strength. Histological and ultrastructural analyses revealed substantial protection against cerebellar Purkinje cell loss and iron deposition, cardiac hypertrophy, and the degree of skeletal muscle atrophy and fibrosis. Proteomic analysis of cerebellar tissue demonstrated that UA-36 robustly reprograms the FA-associated molecular landscape by upregulating pathways related to autophagy, mitochondrial biogenesis, oxidative phosphorylation, and redox homeostasis, while suppressing apoptosis and neuroinflammatory signaling. Together, these findings identify UA-36 as a promising lead compound and provide compelling evidence that therapeutic enhancement of autophagy and mitochondrial quality control represents a viable, mechanism-based strategy for the treatment of FA.