A downstream LRRK2-Rab10-JIP4 lysosomal stress loop promotes alpha-synuclein re…

Mechanistic description

Even if G2019S mainly elevates the kinase floor, that increase may still become pathogenic by pushing a thresholded downstream program in which swollen lysosomes recruit LRRK2, phosphorylate Rab10, engage JIP4-dependent remodeling, and increase extracellular alpha-synuclein release. This is plausible disease biology and a useful secondary discriminator, but it remains less direct than the baseline-versus-gain question.

Mechanism / pathway

LRRK2,RAB10,JIP4,SNCA
→
neurodegeneration

Evidence for (7)

Lysosomal stress promotes alpha-synuclein release through an LRRK2-Rab10-dependent pathway in macrophage-lineage cells and microglia.

PMID:38313055
LRRK2-dependent lysosomal tubulation and sorting provide a plausible export mechanism downstream of Rab phosphorylation.

PMID:33177079
Microglia rescue neurons from aggregate-induced neuronal dysfunction and death through tunneling nanotubes.

PMID:39059388 2024 Neuron
Parkinson's Disease Genetics and Pathophysiology.

PMID:34236893 2021 Annu Rev Neurosci
Microglia jointly degrade fibrillar alpha-synuclein cargo by distribution through tunneling nanotubes.

PMID:34555357 2021 Cell
The cell biology of Parkinson's disease.

PMID:33749710 2021 J Cell Biol
The LRRK2 kinase substrates RAB8a and RAB10 contribute complementary but distinct disease-relevant phenotypes in human neurons.

PMID:38307024 2024 Stem Cell Reports

Evidence against (2)

Current evidence does not isolate G2019S-specific amplification from a more generic lysosomal stress secretion pathway.

PMID:38313055
Extracellular alpha-syn release can also arise from generalized lysosomal overload, cell injury, or inflammasome-linked secretion.

PMID:38313055

Evidence matrix

7 supporting 2 contradicting

53% posterior support

Supporting

Lysosomal stress promotes alpha-synuclein release through an LRRK2-Rab10-dependent pathway in macrophage-lineage cells and microglia. PMID:38313055
LRRK2-dependent lysosomal tubulation and sorting provide a plausible export mechanism downstream of Rab phosphorylation. PMID:33177079
Microglia rescue neurons from aggregate-induced neuronal dysfunction and death through tunneling nanotubes. PMID:39059388 · 2024 · Neuron
Parkinson's Disease Genetics and Pathophysiology. PMID:34236893 · 2021 · Annu Rev Neurosci
Microglia jointly degrade fibrillar alpha-synuclein cargo by distribution through tunneling nanotubes. PMID:34555357 · 2021 · Cell
The cell biology of Parkinson's disease. PMID:33749710 · 2021 · J Cell Biol
The LRRK2 kinase substrates RAB8a and RAB10 contribute complementary but distinct disease-relevant phenotypes in human neurons. PMID:38307024 · 2024 · Stem Cell Reports

Contradicting

Current evidence does not isolate G2019S-specific amplification from a more generic lysosomal stress secretion pathway. PMID:38313055
Extracellular alpha-syn release can also arise from generalized lysosomal overload, cell injury, or inflammasome-linked secretion. PMID:38313055

Bayesian persona consensus

53% posterior support

1 signal · 1 for / 0 against · agreement 100%

scidex.consensus.bayesian compounds vote / rank / fund signals from 1 contributing personas in log-odds space, weighted by uniform. Prior 50%.

Cite this hypothesis

Citation

etl-backfill (2026). A downstream LRRK2-Rab10-JIP4 lysosomal stress loop promotes alpha-synuclein re…. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-dd0fe43949

BibTeX

@misc{scidex_hypothesis_hdd0fe43,
  title        = {A downstream LRRK2-Rab10-JIP4 lysosomal stress loop promotes alpha-synuclein re…},
  author       = {etl-backfill},
  year         = {2026},
  howpublished = {SciDEX hypothesis},
  url          = {https://prism.scidex.ai/hypotheses/h-dd0fe43949},
  note         = {SciDEX artifact hypothesis:h-dd0fe43949}
}