PT  - JOURNAL ARTICLE
AU  - Justyna Okarmus
AU  - Jette Bach Agergaard
AU  - Tina C. Stummann
AU  - Henriette Haukedal
AU  - Malene Ambjørn
AU  - Kristine K. Freude
AU  - Karina Fog
AU  - Morten Meyer
TI  - USP30 inhibition induces mitophagy and reduces oxidative stress in parkin-deficient and CCCP-stressed human iPSC-derived neurons
AID  - 10.1101/2022.06.29.498100
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.06.29.498100
4099  - http://biorxiv.org/content/early/2022/07/02/2022.06.29.498100.short
4100  - http://biorxiv.org/content/early/2022/07/02/2022.06.29.498100.full
AB  - Ubiquitination of mitochondrial proteins plays an important role in the cellular regulation of mitophagy. The E3 ubiquitin ligase parkin (encoded by PARK2) and the ubiquitin-specific protease 30 (USP30) have both been reported to regulate ubiquitination of outer mitochondrial proteins and thereby mitophagy. Loss of E3 ligase activity is thought to be pathogenic in both sporadic and inherited Parkinson’s disease (PD), with loss-of-function mutations in PARK2 being the most frequent cause of autosomal recessive PD.The aim of the present study was to evaluate whether mitophagy induced by USP30 inhibition provides a functional rescue in isogenic human induced pluripotent stem cell-derived dopaminergic neurons with and without PARK2 knockout (KO).Our data show that healthy neurons responded to CCCP-induced mitochondrial damage by clearing the impaired mitochondria and that this process was accelerated by USP30 inhibition. Parkin-deficient neurons showed an impaired mitophagic response to CCCP challenge, although mitochondrial ubiquitination was enhanced. USP30 inhibition promoted mitophagy in PARK2 KO neurons, independently of whether left in basal conditions or treated with CCCP. In PARK2 KO, as in control neurons, USP30 inhibition balanced oxidative stress levels by reducing excessive production of reactive oxygen species. Interestingly, non-dopaminergic neurons, were the main driver of the beneficial effects of USP30 inhibition.Our findings demonstrate that USP30 inhibition is a promising approach to boost mitophagy and improve cellular health, also in parkin-deficient cells, and support the potential relevance of USP30 inhibitors as a novel therapeutic approach in diseases with a need to combat neuronal stress mediated by impaired mitochondria.Competing Interest StatementT.C.S., M.A., and K.F. work for the pharmaceutical company H. Lundbeck A/S.