B08 Differential sensitivity of aggregate markers in HdhQ150 and YAC128 HD mouse models

Abstract

Huntington's disease (HD), an inherited neurodegenerative disorder that is characterised histologically by the presence of intranuclear inclusions (NIIs) and the loss of neurons in the striatum and cortex. Protein aggregates are a hallmark of several neurodegenerative disorders including HD. These aggregates contain a variety of other proteins including ubiquitin. The present study was designed to determine the sensitivity of the different antibody in inclusion formations in knock-in HdhQ150 and transgenic YAC128 mouse lines. In order to fully assess the different protein deposition patterns in these mouse models, brains were assessed using S830 or ubiquitin immunohistochemistry at 8 and 18 months of age. In 8 months old HdhQ150 and YAC128 carrier mice, ubiquitin antibody showed more diffuse staining with minimum NIIs in the olfactory tubercle, striatum, piriform cortex, cortex and hippocampus. However, at the same age, the S830 antibody showed more specific binding to NIIs in the HdhQ150 but not in YAC128 mice. As would be predicted the deposition of aggregated protein becomes more widespread at later ages. At 18 months of age the HdhQ150 mice showed increased ubiquitin immunoactivity, however there was little difference found in the YAC128 mice. NIIs were visible with the S830 antibody in the HdhQ150 and YAC128 mice at this stage. The present study demonstrates that the differential sensitivity of different antibodies in identifying NIIs between mouse lines, which may reflect confirmatinal changes in protein aggregates.