| Attribute |
Value |
| Study Type |
Preclinical + Clinical Biomarker |
| Duration |
36 months |
| Phase |
Proof-of-Concept |
| Primary Endpoint |
CSF senescence biomarkers correlation with disease progression |
| Secondary Endpoints |
Senolytic treatment effects on motor symptoms, alpha-synuclein pathology |
Cellular senescence in the substantia nigra acts as an upstream driver of dopaminergic neurodegeneration in Parkinson's disease through SASP-mediated neuroinflammation and direct effects on protein aggregation. Senolytic therapy will slow disease progression by clearing senescent cells.
Experiment 1: Senescence Induction in Patient-Derived Neurons
- Cell lines: iPSC-derived dopaminergic neurons from:
- PD patients (LRRK2 G2019S, GBA N370S, idiopathic)
- Healthy controls
- Ataxia-telangiectasia (positive control for senescence)
- Senescence induction:
- Oxidative stress (H₂O₂ 100µM, 2h)
- Mitochondrial toxins (rotenone 1µM, 6h; CCCP 10µM)
- Alpha-synuclein pre-formed fibrils (PFFs, 2µM)
- Assays:
- SA-β-galactosidase staining
- p16INK4a, p21CIP1 immunostaining
- SASP factor secretion (IL-6, IL-8, TNF-α ELISA)
- γH2AX foci counting
- Sample size: 15 lines per group
Experiment 2: SASP-Alpha-Synuclein Crosstalk
- Setup: Co-culture of senescent fibroblasts with healthy dopaminergic neurons
- Readouts:
- Alpha-synuclein phosphorylation (pSer129)
- Oligomer formation (STED microscopy)
- Neuronal viability (MTS assay)
- Intervention arms:
- IL-6 neutralizing antibody
- IL-8 neutralizing antibody
- TGF-β inhibitor
- Senolytic treatment (D+Q)
Experiment 3: Senolytic Efficacy in vitro
- Drugs: Dasatinib (100nM) + Quercetin (10µM), Fisetin (10µM), Navitoclax (1µM)
- Models: Senescent iPSC-derived dopaminergic neurons (induced by oxidative stress)
- Readouts:
- Senescent cell clearance (SA-β-gal reduction)
- Viability of non-senescent cells (selectivity)
- Alpha-synuclein pathology changes
- Mitochondrial function (Seahorse assay)
Experiment 4: Senolytic Treatment in Mouse Models
- Models:
- MitoPark mice (mitochondrial PD model)
- α-synuclein PFF mice (protein aggregation model)
- Aged C57BL/6 mice (senescence model)
- Treatment arms:
- Dasatinib + Quercetin (D+Q) oral, 5 days on/9 days off
- Fisetin dietary supplementation
- Vehicle control
- Assessments:
- Motor behavior (rotarod, cylinder test, gait analysis)
- Dopaminergic neuron survival (TH+ cell count in SNc)
- Alpha-synuclein pathology (pSer129, insoluble aggregates)
- SASP marker levels (IL-6, IL-8 in brain tissue)
- Senescence markers (p16-LacZ reporter)
Experiment 5: Senescence Cell-Type Mapping
- Method: Single-cell RNA sequencing of PD vs. control substantia nigra
- Cell types: Neurons, microglia, astrocytes, oligodendrocytes
- Senescence signatures: p16INK4a, CDKN1A, SASP genes
- Spatial transcriptomics: Spatial localization of senescent cells
Cohort Study: Senescence Biomarkers in PD
- Participants:
- Early-stage PD (n=100, Hoehn & Yahr 1-2)
- Advanced PD (n=100, Hoehn & Yahr 3-4)
- Healthy age-matched controls (n=100)
- Biomarkers:
- Blood: p16INK4a mRNA (PBMCs), senescence-associated secretory phenotype (SASP) factors
- CSF: IL-6, IL-8, TNF-α, TGF-β1, VEGF
- Imaging: TSPO PET for microglial activation (correlate with senescence)
- Correlations:
- Biomarker levels with MDS-UPDRS scores
- Biomarker levels with disease duration
- Longitudinal changes over 18 months
Study: Senolytic Therapy in PD (SENOL-PD Pilot)
- Design: Randomized, double-blind, placebo-controlled
- Intervention: Dasatinib (100mg daily) + Quercetin (500mg daily), 5 days on/9 days off, 12 weeks
- Participants: Early-stage PD (n=30, 15 per arm)
- Endpoints:
- Primary: Safety and tolerability
- Secondary: MDS-UPDRS change, blood senescence biomarkers
- Exploratory: CSF SASP factors, alpha-synuclein seeding activity
- Duration: 12 weeks treatment + 12 weeks follow-up
- Phase 1: n=15 per group provides 80% power to detect 30% difference in senescence markers (α=0.05)
- Phase 2: n=100 per group provides 80% power to detect 0.5 SD difference in biomarkers (α=0.05)
- Phase 3: n=15 per arm provides 80% power to detect 5-point UPDRS improvement (α=0.05)
- Mixed-effects models for longitudinal data
- Multiple comparison correction (Bonferroni)
- Correlation analysis (Pearson/Spearman)
- Kaplan-Meier for progression analysis
- Confirm senescence presence: Elevated senescence markers in PD SNc vs. controls
- Identify drivers: SASP factors that most strongly correlate with pathology
- Validate biomarkers: Blood/CSF biomarkers that track with disease progression
- Establish therapeutic window: Safety and preliminary efficacy of senolytic therapy
- Mechanistic insights: Cell-type specific contribution to neurodegeneration
| Risk |
Mitigation |
| Off-target effects of senolytics |
Careful dose-finding, monitoring of hematologic parameters |
| Biomarker variability |
Multiple biomarkers, longitudinal sampling |
| Species differences |
Use human iPSC models alongside mouse models |
| Limited brain penetration |
Choose drugs with CNS penetration, monitor CSF biomarkers |
| Phase |
Cost |
Notes |
| Phase 1 (Preclinical) |
$800K |
iPSC lines, animal studies, scRNA-seq |
| Phase 2 (Biomarker) |
$400K |
Cohort study, biomarker assays |
| Phase 3 (Pilot trial) |
$600K |
Clinical trial costs |
| Total |
$1.8M |
|
- Pre-IND meeting with FDA for senolytic combination therapy
- Orphan drug designation consideration given limited treatment options
- Biomarker qualification pathway for senescence biomarkers