miR-29 appears to inhibit PINK1-PRKN-mediated mainly through ATG9A, with two rare ATG9A variants behaving as loss-of-function in cells.
Evidence
This mechanistic cell study used genome-wide imaging miRNA screening, RNA sequencing, ATG9A silencing and rescue assays, and experimental testing of two rare EOPD-cohort ATG9A variants.
Caveat
Disease relevance is uncertain because the rare variants were nominated from an EOPD patient cohort and functionally tested in cells rather than proven causal in patients.
Simplified
UNLABELLED: Loss-of-function mutations in the genes encoding PINK1 and PRKN result in early-onset Parkinson disease (EOPD). Together, the encoded enzymes direct a neuroprotective pathway that ensures the elimination of damaged mitochondria via autophagy. We performed a genome-wide high-content imaging miRNA screen for inhibitors of the PINK1-PRKN pathway and identified all three members of the miRNA family 29 (miR-29). RNA sequencing revealed target genes regulated by miR-29 and identified ATG9A as a candidate gene. SiRNA-mediated ATG9A silencing phenocopied the effects of miR-29 and suppressed the initiation of PINK1-PRKN-mediated . In addition, expression of ATG9A was able to rescue the effects of miR-29a, suggesting that ATG9A is primarily responsible for the inhibitory effect of miR-29. In an EOPD patient cohort, we further discovered two rare, potentially deleterious,missense variants (p.R631W and p.S828L) and tested them experimentally in cells. Strikingly, neither EOPDvariant was able to rescue the phenotype suggesting they both act as loss-of-function mutations and might contribute to the etiology of disease. Together, our study validates miR-29 and its target gene ATG9A as novel regulators of PINK1-PRKN signaling. It further serves as proof-of-concept with the identification of novel, potentially disease-relevant EOPD variants specifically in mitophagy-regulating genes. The nomination of biological pathways is important for the stratification and treatment of patients that suffer from devastating diseases, such as EOPD. ATG9A ATG9A
SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s44477-026-00029-w.
Key numbers
50%
Decrease in PRKN translocation
Reduction in PRKN translocation observed with miR-29a transfection.
208
EOPD cohort size
Total number of individuals screened for ATG9A mutations in the study.
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