Year 2

Our goal is to define the factors involved in choroid plexus epithelial (CPe) cell development in mice, then to apply this knowledge to generate CPe cells from mouse and human embryonic stem cells (ESCs) for clinical applications. The first two Aims examine Fgf8 and Lhx2 as promoter and inhibitor, respectively, of CPe fate, and the third Aim is to generate human CPe cells in culture. Unexpectedly, we obtained significant evidence for CPe differentiation from both mouse and human ESCs during year 1 of the award. Our aims for year 2 were therefore modified to accelerate the translation of our findings towards a CPe-based regenerative medicine. This year, we developed a second cell culture system for deriving mouse CPe cells, and established a functional assay for CPe cells in culture, which we used to confirm the function of our derived mouse CPe cells. To sort and purify CPe cells for clinical applications, we began characterizing CPe cell complexity, size, and mitochondrial content by flow cytometry, obtained a mouse line with fluorescent CPe cells, and identified three antibodies that may be useful for sorting human CPe cells. A stereotaxic injection system was built, and institutional approvals were obtained, to establish methods for replacing or transplanting CPe cells in the mouse brain.