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Generation and characterization of embryonic stem cell lines derived from the YAC128 mouse model of Huntington disease. Thiele, Jenny

Abstract

Huntington Disease (HD) is an autosomal dominant neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the Huntingtin gene. Patients typically present in mid-life with progressive motor dysfunction, cognitive deficits, and neuropsychiatric abnormalities. Recently, researchers have provided evidence that HD is associated with significant pathology in peripheral tissues as well. At the current time no effective treatment has been proven to alter or cure progression of HD which leads to complete loss of independence and eventual death an average of 20 years after disease onset. The ability to model Huntington disease in animals has enabled studies which have provided new insights into the mechanisms of HD pathogenesis. However, the development of simple cell culture-based systems will be useful to accelerate our research efforts into the basic underlying pathogenic pathways of HD and will allow dissection of cellular interactions and the identification of novel targets for intervention that offer the greatest hope of a cure. The YAC mouse model of HD expresses full-length human Huntingtin with either 18 polyglutamines (YAC18) or 128 polyglutamines (YAC128), and develops age-dependent cognitive deficits, motor dysfunction, and selective striatal neurodegeneration similar to that seen in human HD patients. I have generated novel embryonic stem (ES) cell lines from wild-type, YAC18 and YAC128 mice on two genetic backgrounds. These cell lines have been cultured under defined conditions over long periods of time, and express characteristic markers of pluripotency, such as alkaline phosphatase, Oct-4 and Nanog. Neurons and macrophages derived from these novel cell lines using established in vitro protocols have been characterized via immunocytochemistry and challenged in functional assays. To confirm results attained from functional assays in our ES-derived macrophages, I examined primary macrophages and microglia cultures derived from the YAC mice and determined the functional response of these cells to endotoxin stimulation. Primary cell cultures isolated from YAC128 mice produced significantly more IL-6 than wild-type cultures. In comparison, with the same endotoxin stimulation, YAC18 primary macrophages and microglia responded with similar levels of IL-6 release as cultures of wild-type cells, suggesting that the over-activity in the YAC128 cytokine response is caused by the mutant Huntingtin transgene.

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Attribution-NonCommercial-NoDerivatives 4.0 International