LRRK2 G2019S mutation contributes to mitochondrial transfer dysfunction in a Drp1-STX17-dependent manner.
Level 5 - mechanism / opinion, no new human data
Bench research using human iPSC-derived in vitro co-culture models
PubMed 41354840 · doi:10.1186/s40035-025-00525-1
What was done
Induced pluripotent stem cells (iPSCs) derived from peripheral blood of one healthy individual and one Parkinson's disease (PD) patient carrying the LRRK2 G2019S mutation were differentiated into dopaminergic (DA) neurons and astrocytes. Astrocyte-DA neuron co-cultures were used to examine mitochondrial transfer after exposure to the environmental toxin rotenone. The researchers assessed the involvement of STX17, TOM20, and Drp1 (including Ser616 phosphorylation) via knockdown and pharmacological intervention with the Drp1 phosphorylation inhibitor DUSP6.
What was found
Rotenone exposure impaired astrocyte-to-DA neuron mitochondrial transfer, with more pronounced impairment in LRRK2 G2019S co-cultures than in healthy control co-cultures. STX17 colocalized with TOM20, and STX17 knockdown disrupted mitochondrial transfer. Drp1 interacted with STX17, and LRRK2 G2019S astrocytes exhibited increased Drp1 phosphorylation at Ser616 upon rotenone exposure along with decreased STX17-TOM20 colocalization. The Drp1 phosphorylation inhibitor DUSP6 restored STX17-TOM20 colocalization, mitochondrial transfer efficiency, and DA neuronal survival. No numerical values or effect sizes were reported in the abstract.
Why it matters
This study identifies impairment of astrocyte-to-neuron mitochondrial transfer via a Drp1-STX17-dependent pathway as a potential mechanism linking genetic (LRRK2 G2019S) and environmental (rotenone) risks in PD. It highlights Drp1 Ser616 phosphorylation as a potential therapeutic target.
Limits
The study is entirely in vitro using iPSC lines from only two individuals (one patient and one control), which risks cell line-specific artifacts. In vitro co-culture does not capture the complexity of intact brain tissue or in vivo pharmacokinetics. No quantitative data or statistical metrics were provided in the abstract.
Cited by
- supports Certain LRRK2 gene variants linked to increased Parkinson's disease risk impair the formation of microtubules used to transfer mitochondria between cells.