The goal of this proposal is to determine the isoform-specific effects of apolipoprotein (apo) E on the development of induced pluripotent stem (iPS) cells into functional neurons both in vitro and in mice. Toward this goal, we have made significant progress in all three aims in the past year, as summarized below.
1) We demonstrated that apoE4-miPSC-derived mNSCs had a greater “age-dependent (passage-dependent)” decrease in generation and/or survival of MAP2-positive neurons in cultures.
2) We also demonstrated that apoE4-miPSC-derived mNSCs had an even greater “age-dependent (passage-dependent)” decrease in generation and/or survival of GAD67-positive GABAergic neurons, as seen in vivo in apoE4 knock-in mice (Li et al., Cell Stem Cell, 2009, 5:634–645).
3) We expanded the pilot study reported last year and confirmed the detrimental effect of apoE4 on GABAergic interneuron development/survival of hiPS cell-derived hNSCs. ApoE4 also increased tau phosphorylation, one of the pathological hallmarks of Alzheimer’s disease, in neurons derived from apoE4-hiPS cells.
4) We established a protocol to transplant apoE-miPS cell-derived mNSCs into mouse brains. The transplanted apoE-mNSCs developed into neurons and astrocytes and integrated into the neural circuitry.