Assessing the Degree of Differentiation in Myotubes derived from Patients with GNE Myopathy

Abstract

GNE Myopathy (GNEM) is an extremely rare autosomal recessive disease that causes muscle wasting due to mutations in the GNE gene. The GNE protein is important for the synthesis of the sugar sialic acid (SA), and such mutations lead to a decrease in SA. Therapies in development seek to restore SA to the muscle, but such therapies are difficult to quantify. A robust biomarker is vital for assessing changes in sialylation that would occur after a therapy, and our lab aims to use myotubes derived from GNEM patient converted myoblasts to do so. However, first, the extent of differentiation of these cells must be determined. If myotubes have not fully differentiated, data may be skewed. Therefore, in order to successfully determine an effective biomarker, we first sought to determine the extent to which cells have fully differentiated into myotubes. To do so, we determined the fusion index as well as expression of myosin heavy chain (MHC) and desmin via immunohistochemistry in myotubes from converted myoblasts. Here, we show the extent of differentiation of myotubes derived from GNEM patients as compared to those derived from their unaffected family members.Support or Funding InformationThis work was supported by funds from the Beta Beta Beta Research Scholarship Foundation Fund.