Year 3

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 have fully characterized two apoE3/3-hiPS cell lines and two apoE4/4-iPS cell lines.

2) We have established NSC lines from human iPS cells with an apoE3/3 or apoE4/4 genotype. The hNSCs have been maintained in suspension or monolayer culture for multiple passages.

3) We demonstrated that apoE4-hNSCs generated ~50% fewer GABAergic interneurons than apoE3-hNSCs in culture. Thus, the detrimental effects of apoE4 on GABAergic interneuron survival, as we observed in vivo in apoE4 knock-in mice (Li G. et al. Cell Stem Cell, 2009, 5:634-645), are recapitulated in cultures of human iPS cell-derived NSCs in vitro.

4) We established protocols in our lab to differentiate human iPS cell-derived NSCs into different types of neurons in cultures.