Endothelial Tube Maintenance in a HUVEC cell Model for Myotonic Dystrophy Type 1

By Grace Holcomb and Jada Gundy

Faculty mentor: Dr. Ginny Morriss

Myotonic dystrophy type 1 (DM1) is a multi-systemic condition that results in severe muscle weakening and wasting. DM1 is caused by an expanded region of CTG repeats in the 3’ untranslated end of the DMPK gene. Muscles require vasculature to supply nutrients and oxygen for muscle maintenance. A previous study involving muscle wasting in a mouse model for DM1, implicated angiogenic genes as contributors to muscle wasting. The ultimate goal of this project is to test whether myokines are involved in communicating between skeletal muscles and vasculature. As a baseline analysis, we wanted to determine whether expression of expanded-CUG repeats in the human umbilical vein endothelial cell (HUVEC) line would disrupt the maintenance of endothelial tubes. The cell line maintenance and passaging were optimized for ideal cell proliferation. HUVEC cells were differentiated, followed by transfection with DMPK exons 11-15 containing either 960 CUG repeats or no CUG repeats, or no additional DNA. Transfected cells were imaged every 3 to 6 hours over 24 hours. Upon visual analysis, the differentiated cells expressing DMPK with a 960 CUG repeat showed degradation of the endothelial tube network when compared to control groups with and without the DMPK gene in both tube-length and tube-width. The quantification of endothelial tube width and length using ImageJ software will establish a baseline response of the endothelial tubes to CUG repeat expression, which can be used to compare further treatments for phenotypic rescue or the effect of conditioned media from myoblast cultures on endothelial tube maintenance and/or development.