Exercise Effects in Huntington's Disease

Huntington disease (HD) is an incurable and fatal disorder that affects muscle function and leads to cognitive decline and dementia. HD was long considered a brain disorder but meanwhile it was shown that HD also affects other tissues such as muscle, leading to muscle wasting. Previous studies suggested that the muscle disorder might be caused by an impaired energy metabolism through mitochondrial dysfunction, which also might also contribute to brain pathology.

In muscle tissue of healthy persons, a protein named PGC 1- α seems to regulate many, if not all of the adaptations of muscle metabolism and mitochondrial biogenesis to chronic endurance training. It was shown that PGC 1- α is reduced in muscle tissue of human HD patients and animal models of HD.

We aim investigating whether endurance exercise has the capability of stabilizing and / or reversing PGC-1α dependent decline of muscle function and structure in HD patients, and whether muscle training ameliorates muscular and cardiovascular function, as well as coordination and cognitive decline in HD. To this end, we will train 20 male HD patients using a 6 months progressive endurance exercise program. In order to compare the size effect of exercise between HD patients and healthy individuals, 20 age-matched healthy males will perform the identical exercise regimen as HD patients. Within one week before the training period starts and within one week after it has ended, we will assess metabolic and functional data. In addition, we will analyze muscle tissue samples for muscle fiber structure, metabolic phenotype and cellular pathology. Finally, gene and protein expression analyses will be performed on muscle tissue extracts to gain insights into the molecular regulation of training adaptations in HD.