Investigating the effects of Apelin-13 on pre-vascularization of engineered skeletal muscle

Tissue-engineered skeletal muscle is a promising platform for in vitro modeling of human muscle diseases and pharmacological testing. However, most engineered skeletal muscle tissues contain only muscle and fibroblasts, lacking the complexity of native muscle, which also includes motorneurons, macrophages, vasculature, etc. The Bursac Lab has been developing a pre-vascularizing engineered skeletal muscle with contractile function comparable to that of avascular, muscle-only engineered tissues. In an effort to improve this platform, we have started to investigate the effects of Apelin-13, previously shown to improve skeletal muscle function in vivo and angiogenesis of endothelial cells in vitro. The main hypothesis of this work has been that Apelin-13 will simultaneously improve both angiogenesis and contractile function of pre-vascularized engineered skeletal muscle. To test this hypothesis, I have been characterizing angiogenesis of human endothelial progenitor cells (EPCs) using a 16-hour Tube Formation Assay with varying concentrations of Apelin-13. By imaging the resulting endothelial networks and quantifying total tube length and area, I expect to show that supplementation of Apelin-13 can promote angiogenesis of EPCs. If successful, I will continue these studies by treating muscle-EPC co-cultures with Apelin-13 and quantifying the effects on muscle structure, function, and formation and stability of vascular networks.