Adult neural progenitor cells from Huntington's disease mouse brain exhibit increased proliferation and migration due to enhanced calcium and ROS signals

Abstract

Objectives: Huntington's disease (HD) is an inherited human neurodegenerative disorder characterized by uncontrollable movement, psychiatric disturbance and cognitive decline. Impaired proliferative/differentiational potentials of adult neural progenitor cells (ANPCs) have been thought to be a pathogenic mechanism involved in it. In this study, we aimed to elucidate intrinsic properties of ANPCs subjected to neurodegenerative condition in YAC128 HD mice. Materials and methods: ANPCs were isolated from the SVZ regions of 4-month-old WT and YAC128 mice. Cell proliferation, migration and neuronal differentiation in vitro were compared between these two genotypes with/without Ca2+ inhibitors or ROS scavenger treatments. Differences in ANPC proliferation and differentiation capabilities in vivo between the two genotypes were evaluated using Ki-67 and Doublecortin (DCX) immunofluorescence respectively. Results: Compared to WT ANPCs, YAC128 ANPCs had significantly enhanced cell proliferation, migration and neuronal differentiation in vitro, accompanied by increased Ca2+ and ROS signals. Raised proliferation and migration in YAC128 ANPCs were abolished by Ca2+ signalling antagonists and ROS scavenging. However, in vivo, HD ANPCs failed to show any elevated proliferation or differentiation. Conclusions: Increased Ca2+ signalling and higher level of ROS conferred HD ANPC enhancement of proliferation and migration potentials. However, the in vivo micro-environment did not support endogenous ANPCs to respond appropriately to neuronal loss in these YAC128 mouse brains.