Expression of the Huntington's disease transgene in neural stem cell cultures from R6/2 transgenic mice

Huntington's disease (HD) is an inherited neurodegenerative disorder resulting in neuronal cell death in discrete brain regions due to an expanded CAG repeat of the huntingtin gene. The transgenic mouse model R6/2 expresses exon 1 of the human huntingtin gene with >150 CAG repeats, which produces mutant HD protein with an expanded poly-glutamine tract. We have established a neuronal stem cell system deriving from transgenic HD R6/2 neonatal brains as a renewable source for neurons and glia to facilitate studies of HD neuropathology and therapies. These R6/2 stem cell cultures can be cryopreserved and revived. Thawed neural progenitors can be expanded, established as continuous cell lines, and induced to differentiate into glia and neurons. Using standard culture conditions, there was no detectable morphological difference between wild type and HDR6/2 cells. Western analysis reveals that R6/2, but not wild type neurospheres, express the expanded repeat transgenic protein. Immunocytochemistry reveals that at a higher antibody concentration, huntingtin can be localized in the nucleus and the cytoplasm of wild type and R6/2 cells. We conclude that the R6/2 neuronal stem cell culture is a valuable tool for investigating HD pathogenesis and potential genetic or pharmacological interventions.