Chemical modulation of Miro1 alleviates cell-type-specific vulnerabilities in Friedreich's ataxia.

Friedreich's ataxia (FA) is marked by early-onset sensory neurodegeneration and cardiomyopathy. We establish a human dual-cell model of FA by differentiating sensory neurons and cardiomyocytes from the same patients, enabling parallel molecular profiling of disease-relevant cell types. Proteomic analysis reveals distinct, cell-type-specific pathway disruptions in response to frataxin deficiency. Leveraging this platform, we investigate Miro1 reducer 3 (MR3), a selective chemical probe binding Miro1, a mitochondrial outer membrane protein implicated in redox regulation in FA. MR3 treatment modulates molecular signatures in a cell-type-dependent manner, altering pathways related to cardiac contractility in cardiomyocytes and synaptic function in sensory neurons. Mechanistically, MR3 reduces mitochondrial reactive oxygen species and restores membrane potential in FA sensory neurons via potential allosteric reshaping of Miro1 protein. We expand the chemical diversity of this scaffold by conducting ligand-based virtual screening of over 3 billion compounds and identifying previously uncharacterized Miro1 ligands with improved docking and neuroprotective capacity.