HSP90-incorporating chaperome networks as biosensor for disease-related pathways in patient-specific midbrain dopamine neurons.

Environmental and genetic risk factors contribute to Parkinson's Disease (PD) pathogenesis and the associated midbrain dopamine (mDA) neuron loss. Here, we identify early PD pathogenic events by developing methodology that utilizes recent innovations in human pluripotent stem cells (hPSC) and chemical sensors of HSP90-incorporating chaperome networks. We show that events triggered by PD-related genetic or toxic stimuli alter the neuronal proteome, thereby altering the stress-specific chaperome networks, which produce changes detected by chemical sensors. Through this method we identify STAT3 and NF-κB signaling activation as examples of genetic stress, and phospho-tyrosine hydroxylase (TH) activation as an example of toxic stress-induced pathways in PD neurons. Importantly, pharmacological inhibition of the stress chaperome network reversed abnormal phospho-STAT3 signaling and phospho-TH-related dopamine levels and rescued PD neuron viability. The use of chemical sensors of chaperome networks on hPSC-derived lineages may present a general strategy to identify molecular events associated with neurodegenerative diseases.

Cortical Differentiation of Human Pluripotent Cells for In Vitro Modeling of Alzheimer's Disease.

Stem cell models of Alzheimer's disease provide an opportunity to study the mechanisms underlying disease pathology at a resolution that is not possible in animal models. Furthermore, the ability to reprogram patient somatic cells to a pluripotent state ensures that the disease can be investigated in the correct genetic context. Here, we describe the directed differentiation of human pluripotent cells to cortical progenitors by recapitulating key developmental signaling events in vitro. Over a timeframe that mirrors human development, these progenitors give rise to functional lower and upper layer neurons. We also describe biochemical and imaging based methods to analyse key APP and Tau phenotypes in neurons generated from pluripotent stem cells from individuals with either monogenic familial Alzheimer's disease or Down's syndrome.