Astrocytes express multiple phagocytic receptors including MEGF10 (multiple EGF-like domains 10) that enable direct synaptic material engulfment independent of microglial activation. This hypothesis proposes that targeted upregulation of astrocytic MEGF10 expression can provide more precise temporal and spatial control over synaptic pruning compared to microglial TREM2 activation. MEGF10 functions through recognition of phosphatidylserine exposure on synaptic terminals marked for elimination, triggering astrocytic process extension and direct engulfment of synaptic material. Unlike the inflammatory cascades associated with microglial activation, astrocytic MEGF10-mediated pruning operates through gentler phagocytic mechanisms that preserve local tissue architecture. The hypothesis predicts that astrocyte-specific MEGF10 overexpression using GFAP-driven vectors will enhance developmental synaptic refinement in neural circuits while avoiding the potential neuroinflammatory side effects of microglial stimulation.
...Curated pathway from expert analysis
flowchart TD
A["Amyloid-beta Plaques<br/>Phospholipid Ligands"]
B["TREM2 Receptor<br/>Ligand Binding"]
C["TYROBP/DAP12<br/>ITAM Phosphorylation"]
D["SYK Kinase<br/>Activation"]
E["PLCG2<br/>IP3 + DAG Generation"]
F["Ca2+ Release<br/>Cytoskeletal Remodeling"]
G["Microglial Phagocytosis<br/>Plaque Compaction"]
A --> B
B --> C
C --> D
D --> E
E --> F
F --> G
style A fill:#b71c1c,stroke:#ef9a9a,color:#ef9a9a
style G fill:#1b5e20,stroke:#81c784,color:#81c784No linked papers recorded for this hypothesis yet.
No curated PDB or AlphaFold mapping for MEGF10 yet. Search RCSB →
Median TPM across 13 brain regions for MEGF10 from GTEx v10.
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 MEGF10.
Run python3 scripts/backfill_hypothesis_depmap.py to populate.
| Prediction | Predicted | Observed | Status | Conf |
|---|---|---|---|---|
| IF we directly compare astrocyte-targeted MEGF10 overexpression versus microglial TREM2 activation (via PLX3397 diet + AAV-TREM2) in juvenile mice (P21-P35), THEN the MEGF10 condition will show equiva | MEGF10 overexpression achieves comparable synaptic pruning efficiency to TREM2 activation while maintaining microglial surveillance state; serum cytokine levels | — no observation — | pending | 0.58 |
| IF we inject GFAP-driven AAV-MEGF10 into adult mouse prefrontal cortex to overexpress astrocytic MEGF10 (compared to AAV-GFP control), THEN synaptic density will decrease by ≥15% and PSD95 puncta will | Significant reduction in excitatory synaptic markers (PSD95, vGLUT1) and decreased dendritic spine density in the injected region, without elevation of inflamma | — no observation — | pending | 0.65 |