This experiment tests the TREM2-Alpha-Synuclein Clearance Hypothesis by evaluating whether TREM2 agonism enhances microglial phagocytosis of alpha-synuclein aggregates and protects dopaminergic neurons in Parkinson's Disease models.
Enhanced TREM2 signaling will:
- Increase microglial phagocytosis of alpha-synuclein fibrils
- Reduce extracellular alpha-synuclein accumulation
- Decrease template-directed misfolding and propagation
- Preserve dopaminergic neuron function and survival
| Parameter |
Specification |
| Source |
Human iPSC-derived microglia or primary mouse microglia |
| Genotypes |
TREM2 wild-type, TREM2 knockout, TREM2 R47H variant |
| Treatment |
Alpha-synuclein preformed fibrils (PFF) ± TREM2 agonist |
- Format: Transwell coculture of microglia + dopaminergic neurons ( Lund human mesencephalic cells or iPSC-derived DA neurons)
- Treatment: TREM2 agonist at 0.1, 1, 10 µg/mL
- Duration: 14 days
- Controls: IgG isotype, vehicle, untremed PFF
| Endpoint |
Method |
Readout |
| Alpha-synuclein uptake |
pSER129 immunostaining, flow cytometry |
Phagocytic index |
| Phagocytic capacity |
pHrodo-labeled alpha-synuclein |
Fluorescence intensity |
| Neuronal survival |
TH+ neuron counting, MAP2 |
% survival vs. control |
| Neuroinflammation |
IL-1β, TNF-α ELISA |
Inflammatory cytokines |
| TREM2 expression |
qPCR, Western blot |
mRNA/protein levels |
| Parameter |
Specification |
| Species |
C57BL/6J mice |
| Model |
Alpha-synuclein preformed fibril (PFF) model |
| Age |
10-12 weeks at study start |
| Sex |
Both males and females |
| Group |
n |
Treatment |
| 1 |
12 |
Vehicle (PBS) |
| 2 |
12 |
TREM2 agonist (5 mg/kg) |
| 3 |
12 |
TREM2 agonist (10 mg/kg) |
| 4 |
12 |
IgG isotype control |
| 5 |
12 |
Alpha-synuclein PFF + TREM2 agonist |
| 6 |
12 |
Alpha-synuclein PFF + vehicle |
- Route: Intraperitoneal injection
- Frequency: Twice weekly
- Duration: 12 weeks
- Timing: Started 2 weeks post-PFF injection (established pathology)
| Test |
Timepoint |
Readout |
| Rotarod |
Baseline, Wk 6, Wk 12 |
Latency to fall (seconds) |
| Cylinder test |
Baseline, Wk 6, Wk 12 |
Forelimb use asymmetry |
| Gait analysis |
Wk 12 |
Stride length, swing speed |
| Open field |
Wk 12 |
Total distance, time in center |
¶ Tissue Collection and Analysis
Terminal endpoint: Week 12
| Tissue |
Analysis |
| Substantia nigra |
TH+ neuron counting (stereology) |
| Striatum |
Dopamine content (HPLC), TH fiber density |
| Motor cortex |
pSER129+ aggregates (IHC) |
| Midbrain |
Microglial TREM2 expression (ISH) |
| CSF |
sTREM2 levels (ELISA) |
| Biomarker |
Sample |
Method |
Purpose |
| sTREM2 |
CSF, serum |
ELISA |
Target engagement |
| NF-L |
Serum |
Simoa |
Neurodegeneration marker |
| Alpha-synuclein RT-QuIC |
CSF |
Seed amplification |
Pathology burden |
| IL-1β, TNF-α |
CSF, tissue |
ELISA |
Neuroinflammation |
- Alpha: 0.05
- Power: 0.80
- Expected effect size: 30% improvement in motor function
- Calculated n: 10-12 per group
- Motor function: Rotarod latency (two-way ANOVA with repeated measures)
- Neuronal survival: TH+ neuron count (one-way ANOVA)
- Alpha-synuclein pathology: pSER129+ burden (t-test)
- Biomarker correlation (Pearson correlation)
- Neuroinflammation scores (Kruskal-Wallis)
- Survival analysis (log-rank test)
- TREM2 agonist improves motor performance in PFF model
- Reduced pSER129+ aggregates in substantia nigra
- Enhanced microglial phagocytosis in vitro
- sTREM2 elevation correlates with improved outcomes
- No motor improvement despite target engagement
- TREM2 agonist increases neuroinflammation
- Limited translation from in vitro to in vivo
- All procedures approved by IACUC
- Minimize animal suffering
- Use of both sexes to identify sex-specific effects
- Endpoints designed to detect therapeutic benefit
Created: 2026-03-23 19:30 PT