CTG expansion and early proliferative arrest of DM1 myoblastes
Myotonic Dystrophy type I is the most common neuromuscular pathology at adult age. DM1 is characterized by a multisystemic but variable phenotype, correlated with the size of the CTG expansion. Skeletal muscle tissue is particularly affected showing myotonic symptoms and atrophy. Myoblasts, responsible for skeletal muscle growth and repair, present in DM1 patients a reduced proliferative capacity compared to cells isolated from non-affected individuals. During a previous study, p16INK4A was identified as the trigger of this abnormal proliferative arrest in DM1 myoblasts, but mechanisms activating this pathway are still unknown. In this study, we attempted to decrypt these mechanisms, particularly the potential links between CTG expansions, oxidative stress sensitivity and early activation of the p16 pathway leading to myoblasts senescence