Screening strategy using a filamentous fungus model to repurpose drugs for mitochondrial complex I deficiencies

This study aimed to repurpose FDA-approved drugs for the treatment of mitochondrial complex I diseases.

The NUO-51 protein of the filamentous fungus Podospora anserina is the homolog of the human key catalytic subunit of complex I, NDUFV1. By introducing a pathogenic mutation into P. anserina NUO-51 we created a novel model of complex I deficiency targeting the NDUFV1 subunit. The thermosensitive phenotype of the fungal mutant enabled us to screen a library of nearly one thousand FDA-approved molecules. We have implemented various techniques such as growth analysis, oxygen consumption measurements, complex I activity assays and western blotting on Podospora, Caenorhabditis elegans and human on equivalent NDUFV1 mutant models, treated or untreated with the most effective drugs found during the screen.

We isolated a series of compounds able to rescue the growth defect of the Podospora nuo-51 mutant, including ligands of serotonin receptors or transporters. Among the selected drugs, alverine citrate (ALV) and dapoxetine hydrochloride (DAP) emerged as the most active drugs. Both drugs enhanced respiration and complex I activity, not only in the Podospora mutant, but also in Caenorhabditis elegans worms deficient for the NDUFV1 ortholog and in fibroblasts from patient carrying NDUFV1 mutations.

Together, our work demonstrates the usefulness of Podospora anserina as fungal model for identifying promising therapeutic candidates for complex I diseases, paving the way for future clinical trials.