Convergence hypothesis: PINK1/Parkin-mediated mitophagy dysfunction in neurons and TREM2-mediated microglial mitophagy failure represent a unified convergence point driving both Parkinson's disease (PD) and Alzheimer's disease (AD) pathophysiology.
PD-specific mechanism: PINK1 kinase phosphorylates Parkin (PRKN) and ubiquitin at mitochondrial outer membrane, triggering clearance of damaged mitochondria. In PD, mutations in PINK1 (PARK6) or PRKN (PARK2) impair this clearance, leading to mitochondrial ROS spillover that accelerates α-synuclein aggregation. The α-synuclein (SNCA) feedback loop then further inhibits mitochondrial complex I (NDUFS7), creating a vicious cycle.
AD-specific mechanism: TREM2 R47H/haploinsufficiency in AD reduces microglial mitophagic capacity, preventing clearance of mitochondrial debris from synapses. Accumulated mitochondrial damage elevates regional oxidative stress, which hyperphosphorylates tau (MAPT) via GSK3B activation and drives amyloid-beta (APP/ABCA1) aggregation. The tau feedback loop further suppresses complex I efficiency, creating a parallel vicious cycle.
Curated pathway from expert analysis
flowchart TD
A["Damaged Mitochondria<br/>ROS and Depolarization"]
B["PINK1 Accumulation<br/>Outer Membrane Signal"]
C["PRKN Parkin Recruitment<br/>Ubiquitin Phosphorylation"]
D["Mitophagosome Formation<br/>STUB1 and Autophagy Adaptors"]
E["TREM2 Microglial Mitophagy<br/>Innate Immune Energy Control"]
F["Failed Mitochondrial Clearance<br/>Inflammatory ROS Loop"]
G["PD SNCA and AD Tau Abeta Convergence<br/>Neurodegeneration"]
A --> B
B --> C
C --> D
E --> D
D -.->|"when impaired"| F
F --> G
style C fill:#1a237e,stroke:#4fc3f7,color:#4fc3f7
style G fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9aNo linked papers recorded for this hypothesis yet.
No clinical trials data linked to this hypothesis yet.
No curated ClinVar variants loaded for this hypothesis.
Run scripts/backfill_clinvar_variants.py to fetch P/LP/VUS variants.
No DepMap CRISPR Chronos data found for PINK1,PRKN,TREM2,STUB1,NDUFS7.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
No resource usage or linked notebooks recorded for this hypothesis yet.
| Prediction | Predicted | Observed | Status | Conf |
|---|---|---|---|---|
| iPSC-derived microglia from TREM2 R47H AD patients with PINK1/PRKN knockdown will show synergistic exacerbation of mitophagy failure, with intracellular Abeta42 increasing more than either interventio | — | — no observation — | open | 0.72 |
| Post-mortem PD substantia nigra and AD prefrontal cortex both show reduced Parkin and TREM2 protein by >40% compared to age-matched controls. | — | — no observation — | open | 0.75 |