Muscular dystrophies represent a group of debilitating disorders marked by progressive deterioration of muscle tissue. Given the mechanical underpinnings of these disorders, the development of effective treatments necessitates disease models that mimic the mechanical loads present in the human body. We introduce a novel in vitro system, Cytostretcher 3D, designed to simulate the mechanical characteristics of muscular dystrophies. By subjecting induced pluripotent stem cell (iPSC)-derived tissues of healthy and Duchenne Muscular Dystrophy (DMD) phenotypes to relevant mechanical stresses, Cytostretcher 3D reveals phenotypic distinctions, highlighting the system’s utility for disease modeling and drug discovery.
We generated 3D musculoskeletal tissues from human iPSCs, representing healthy and DMD phenotypes, using the commercially available MantarrayTM two-post tissue platform. Tissue testing was conducted at least 14 days after casting tissues. Using a motor-based stretching paradigm, we implemented tensile testing in Cytostretcher 3D and evaluated the mechanical properties of tissues. To recreate the eccentric loading patterns experienced in vivo, Cytostretcher 3D was programmed to apply custom electromechanical stimulation waveforms. Tissue functionality was assessed by measuring their contractile force in the MantarrayTM system, and injury-induced damage was validated by measuring the release of Creatine kinase in the culture media.
Our system effectively identified the elevated mechanical stiffness associated with DMD. Moreover, the combination of electrical plus mechanical stimulation uniquely resulted in functional impairment that was sustained for 24 hours and accompanied by the release of creatine kinase 2 hrs post-injury.
Our system offers a novel experimental framework for a more comprehensive characterization and replication of diseases with a mechanical basis, facilitating more precise and streamlined therapeutic investigations. The adaptable nature of electromechanical stimulation permits the scalable reproduction of diverse tissue stress patterns in vitro. The functional and molecular alterations observed in our findings align with in vivo indications of mechanical injury, underscoring the practicality of our system.