By Jessie Bronski

Faculty Mentor: Ginny Morriss

Abstract

Myotonic dystrophy 1 (DM1) is a multisystemic disease that affects a variety of organ systems characterized by muscle weakness and wasting. DM1 is caused by expanded CTG repeats in the 3’ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. Nonaffected individuals carry fewer than 35 CTG repeats, whereas in DM1 affected individuals the number can range from 35 to greater than 100, with greater number of repeats correlating to earlier onset and increasing severity of the symptoms. The repeats create an expanded DMPK mRNA that sequesters Muscleblind-like (MBNL-1) proteins, preventing them from performing normal splicing functions, leading to symptoms of DM1. Magnesium is one of the most abundant cations present in the body, playing an essential role in muscle growth, viability, and myogenic gene regulation. Prior studies provide evidence that additional amounts of magnesium through supplement or diet, may aid in preventing age-related skeletal muscle loss, indicating magnesium potential in prevention of muscle degradation in patients with Myotonic Dystrophy. To test this, Wilusz MB-C and Wilusz MB-DM480 cell lines were treated with 0, 2.5, 5, and 10 mM of magnesium for 24 hours prior to testing. Trypan blue was then used to measure cell viability by counting the number of alive and dead cells present. A Three-way Anova was initially run with magnesium concentrations, cell type, and cell viability. Magnesium was found to be nonsignificant and removed from further analysis. A Two Way Anova showed no significant interaction between cell type and cell viability. The Two Way Anova was significant for cell type (p = 0.0208) and cell viability (p = 3.32 x 10-13). Normality and constant variance assumptions were violated, resulting in a resampling method being required. The results from the resampling method were approximately the same as Two Way Anova with cell type (p = 0.0203) and cell viability (p = 2 x10-16) being significant, providing evidence that cell type and cell viability have an effect on cell number.