The Alzheimer's Therapeutics Screening Assay: a high-throughput drug-discovery platform utilizing neurons and microglia derived from human induced pluripotent stem cells and Kinetic Image Cytometry

Alzheimer s DiseaseADthe most common cause of dementiaincreases with ageafflictsmillion people in the USand there is no cureThis phase I project will initiate development of the Alzheimer s Therapeutics Screening AssayATSAwhich will utilize neuronsmicrogliaand astrocytesderived from human induced pluripotent stem cellsA new testing system is desperately needed as previously FDA approved therapeutics for AD have limited and temporary effectsand no new drug has been approved for AD sincethe many failed clinical trials since then illustrate that current preclinical models are not sufficiently predictive for ADAs amyloid beta peptideAplaques accumulate in the brains of AD patientspharmaceutical companies have exhaustively targeted the beta amyloid cascade pathway for drug discoveryHoweverwhile many of these agents reduced plaquesnone effectively slowed or prevented memory loss in clinical trialsFunctional magnetic resonancefMRIstudies show that subjects with amnestic mild cognitive impairmentaMCIa prodromal symptom of ADdisplay hyperactive hippocampal neurons prior to plaque formationsuggesting that dysregulation of neuronal calcium may underlie ADRelatedlymicrogliathe resident immune cells of the brainare activated in AD and secrete glutamate and inflammatory cytokines that may alter neuronal calciumFurthermorethe greatest genetic risk for AD is isoformof apolipoprotein EAPOEand proteolytic fragments of APOEcause dysregulation of intracellular calcium and are toxic to neurons and microgliaFor the ATSAmethods will be developed in which hiPSC neuronsMGandastrocytes are cocultured and ADrelevant stressese gAPOEfragments or Aoligomersaddedand the cells monitored for alterations in calciumor voltageusing Kinetic Image Cytometrya digital microscopy method that quantifies calcium transient activity on a cell by cell basisCell morphologyneuritessynaptic punctaand relevant biomarkers will also be quantifiedThe ATSA will be versatileand phase II goals will include utilizing iPSCs from patients with inherited or sporadic ADrepresenting both genderswill be incorporated to further interrogate AD relevant pathwaysOnce developedthe ATSA platform will enable testing of hundreds of compounds per day to identify those with beneficial effects against AD related stressesThe ATSA will be marketed by Vala Sciences Inc for contract research to pharmaceutical companies developing novel therapeutics for ADand used for internal drug discovery by Vala researchers Alzheimer s DiseaseADthe most common cause of dementiaafflictsmillion people in the USand there is no cureUnfortunatelyno new drug has been approved to treat AD sinceand that one has only partialtemporarybenefitillustrating that current preclinical modelsrodents bioengineered to have AD pathologiesdo not predict effects of the test agents in human beingsThe Alzheimer s Therapeutics Screening AssayATSAto be developed by this project will take advantage of thestem cell revolutionto develop novel therapeutics for ADNeurons and other cell types representing the human brain will be differentiated from human stem cellsthe type of stem cells to be used are reprogrammed cells obtained fromskin punchbiopsies from adult humanshuman embryos are not destroyed to derive this type of stem celland cultured inorwell dishestest agents will then be addedthe activity of the cells recorded and analyzed via automated digital microscopesOnce developedthe ATSA will enable testing of hundreds of compounds per day for potential beneficial effects to accelerate development of effective AD therapeutics