Muscular cell cultures show features of dysfunction and apoptosis in Huntington's disease

Mutated huntingtin is widely expressed in tissues of Huntington’s disease (HD) patients. In the brain, mutated protein leads to neuronal death and formations of huntingtin positive inclusions. To gain insight into the cellular abnormalities induced by endogenous mutated huntingtin in tissues of HD patients, the authors analysed huntingtin immunoreactivity, viability, and apoptotic system activation in myoblast cultures obtained from seven HD patients (two presymptomatic patients) and nine controls. Myoblasts, from both presymptomatic and symptomatic HD patients, present robust cellular abnormalities in vitro, namely htt positive inclusion formation and apoptotic event, including mitochondrial depolarisation and increased caspase activities. Our findings strongly suggest that mutant huntingtin is toxic to cells early in life, even outside the central nervous system.