Proteostasis Network Collapse Drives Neurodegeneration with No Way to Restore It

Cells maintain protein quality through chaperones, the proteasome, and autophagy. This system collapses with age, allowing misfolded proteins to accumulate — causing Alzheimer's (amyloid/tau), Parkinson's (alpha-synuclein), and cataracts. ISRIB dramatically improved memory in aged mice but has not yet translated to humans.

The heat shock response diminishes ~50% in aged cells. Proteasome activity drops (20S and 26S). Chaperone-mediated autophagy (CMA) declines. ISRIB (eIF2B activator) improved memory in aged mice by modulating the integrated stress response. Ana Maria Cuervo identified LAMP2A as rate-limiting for CMA. Proteostasis Therapeutics attempted to drug this network but dissolved, illustrating the difficulty.

Why It Matters

Protein misfolding diseases affect 50M+ worldwide. Alzheimer's costs US $355B/year (projected $1T by 2050). Cataracts are leading cause of blindness globally (65M people). NIH Alzheimer's budget: $3.7B/year.

Startup Approach

Develop optimized ISRIB analog with better pharmacokinetics for age-related cognitive decline (not Alzheimer's specifically). Or develop LAMP2A stabilizer to enhance CMA across tissues. Target mild cognitive impairment (MCI) as initial indication.

NIH Funding

NIA Geroscience portfolio includes proteostasis as core pillar. NIH Alzheimer's budget $3.7B/year. NIH Reporter: 300+ active grants on proteostasis and aging.

Who's Working On It

Peter Walter (UCSF/Altos Labs, ISRIB discoverer), Ana Maria Cuervo (Einstein, CMA), F. Ulrich Hartl (Max Planck, chaperone biology)