Electrophysiological analysis of healthy and dystrophic 3D bioengineered skeletal muscle tissues

Abstract

Recently, methods for creating three-dimensional (3D) human skeletal muscle tissues from myogenic cell lines have been reported. Bioengineered muscle tissues are contractile and respond to electrical and chemical stimulation. In this study we provide an electrophysiological analysis of healthy and dystrophic 3D bioengineered skeletal muscle tissues. We focus on Duchenne muscular dystrophy (DMD), a fatal muscle disorder involving the skeletal muscle system. The dystrophin gene, which when mutated causes DMD, encodes for the Dystrophin protein, which anchors the cytoskeletal network inside of a muscle cell to the extracellular matrix outside the cell. Here, we enlist a 3D in vitro model of DMD muscle tissue, to evaluate an understudied aspect of DMD, muscle cell electrical properties uncoupled from presynaptic neural inputs. Our data shows that electrophysiological aspects of DMD are replicated in the 3D bioengineered skeletal muscle tissue model. Furthermore, we test a block co-polymer, poloxamer 188, and demonstrate capacity for improving the membrane potential in DMD muscle.Therefore, this study serves as the baseline for a new in vitro method to examine potential therapies directed at muscular disorders.

Dystrophin is a mechanical tension modulator

“…Here, we used cell lines derived from 6 different donors and from biopsies originating from three different muscle groups (Table 1). As recently reported, all of these cell lines are capable of forming functional biomimetic skeletal muscle tissues within 3D protein scaffolds by self-organizing around two vertical posts [42,17] . With these human immortalized myoblast cell lines from healthy and DMD backgrounds, and our previously developed glass bottom chamber for high resolution imaging [22] , we cultured bioengineered skeletal muscles within a 3D fibrin-Geltrex(tm) scaffold over two weeks (Figure 1 a-d).…”

“…For this reason, numerous in vitro strategies have emerged in recent years for cultivating self-organizing, human multinucleated myotubes within 3D extracellular matrix (ECM) scaffolds [31,2,1,22] . Based on this, the first 3D bioengineered human skeletal muscle disease models were reported only recently, and offer great opportunities to further fundamental research and drug development [32,44,42,17,55,51] . By contrast to 2D myotube culture, these approaches support studies of the force generating capacity of normal and DMD muscle tissue upon stimulating a contraction.…”