Hsp90 Inhibitors For Neurodegeneration is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
HSP90 (Heat Shock Protein 90) inhibitors represent a promising therapeutic strategy for neurodegenerative diseases by targeting proteostasis dysfunction, a hallmark of disorders characterized by misfolded protein accumulation. HSP90 is a molecular chaperone that plays a critical role in folding, stabilization, and quality control of numerous client proteins, including many implicated in neurodegeneration. By inhibiting HSP90, these compounds promote the clearance of toxic protein aggregates through the proteasome and autophagy pathways.
HSP90 is an abundant cytosolic chaperone (1-2% of total cellular protein) essential for cellular proteostasis:
| Property | Details |
|---|---|
| Structure | Homodimer, each monomer ~90 kDa |
| ATPase Cycle | ATP binding → conformational change → hydrolysis → client protein folding |
| Client Proteins | ~200 known, including kinases, transcription factors, receptors |
| Co-chaperones | Hsp70, Hsp40, Hop, CHIP, p23 |
In neurodegenerative diseases, HSP90 plays a paradoxical role:
Protective Function
Pathogenic Function
HSP90 inhibitors shift the equilibrium toward protein degradation:
ATPase Inhibition
Client Protein Degradation
Heat Shock Response Activation
| Property | Details |
|---|---|
| Class | Synthetic small molecule |
| Target | HSP90 (N-terminal) |
| Affinity | IC50 ~ 2 nM |
| Status | Clinical trials in oncology; preclinical in neurodegeneration |
Key features:
| Property | Details |
|---|---|
| Class | Natural product derivative |
| Target | HSP90 |
| Affinity | IC50 ~ 20-65 nM |
| Status | Preclinical; clinical trials in oncology |
Key features:
| Property | Details |
|---|---|
| Class | Natural product derivative |
| Target | HSP90 |
| Status | Clinical trials in oncology |
Key features:
| Property | Details |
|---|---|
| Class | Purine scaffold |
| Target | HSP90 (selective) |
| Status | Clinical trials in oncology; preclinical in neurodegeneration |
Key features:
| Compound | Class | Status |
|---|---|---|
| NVP-HSP990 | Synthetic | Preclinical |
| KW-2478 | Synthetic | Preclinical |
| AT13387 | Synthetic | Preclinical |
| XL888 | Synthetic | Preclinical |
| Compound | Model | Key Findings |
|---|---|---|
| Ganetespib | 3xTg AD mice | Reduces Aβ and tau pathology; improves cognition |
| 17-AAG | APP/PS1 mice | Reduces amyloid plaques |
| PU-H71 | Tauopathy models | Clears tau aggregates |
Mechanisms:
| Compound | Model | Key Findings |
|---|---|---|
| Ganetespib | α-synuclein models | Reduces α-synuclein aggregation |
| 17-DMAG | MPTP model | Protects dopaminergic neurons |
| 17-AAG | α-synuclein tg mice | Improves motor function |
Mechanisms:
| Compound | Model | Key Findings |
|---|---|---|
| 17-DMAG | SOD1 mice | Extends survival |
| Ganetespib | TDP-43 models | Reduces TDP-43 pathology |
| 17-AAG | SOD1 G93A mice | Improves motor function |
Mechanisms:
| Compound | Model | Key Findings |
|---|---|---|
| 17-DMAG | R6/2 mice | Reduces mutant huntingtin; improves motor function |
| Ganetespib | Cell models | Promotes huntingtin clearance |
| HSP90 inhibitors | Various | Reduce aggregation, improve phenotype |
Mechanisms:
| Disease | Compound | Evidence |
|---|---|---|
| Frontotemporal Dementia | Various | Reduces tau and TDP-43 pathology |
| Prion Disease | 17-AAG | Reduces PrPsc in cell models |
| Multiple System Atrophy | Ganetespib | Active in α-synuclein models |
HSP90 inhibitors may be combined with:
Heat Shock Response Side Effects
On-target Effects
Brain Penetration
Therapeutic Window
Selective Brain-Penetrant Inhibitors
Allosteric Inhibitors
Proteostasis Modulation
Combination Therapies
HSP90 inhibitors offer a unique approach to neurodegenerative disease by enhancing proteostasis through modulation of the chaperone system. By inhibiting HSP90, these compounds promote the clearance of toxic protein aggregates (Aβ, tau, α-synuclein, mutant huntingtin, TDP-43) while activating protective heat shock responses. Ganetespib, PU-H71, and 17-DMAG have shown promising results in preclinical models of AD, PD, ALS, and HD. Key challenges include brain penetration, therapeutic window optimization, and managing on-target toxicity. The field is moving toward combination approaches that enhance proteostasis through multiple mechanisms.
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