Validation of 3D-muscle on chip platform for patient oriented preclinical studies in Duchenne Muscular Dystrophy

Moving towards patient oriented preclinical studies on Duchenne muscular dystrophy (DMD) and other rare neuromuscular diseases is essential for elucidating pathological mechanisms and validating tailored therapeutic strategies. In this context, organ-on-chip technologies have emerged as promising platforms for their ability to mimic the complexity of human organs in vitro as well as for rapid and ethical drug screening. Validation of this technology requires reproducibility and high throughput number for robust and repeatable preclinical data. Here, we present a large study on functional fibrin- based skeletal muscle on chips from immortalized precursors obtained from DMD patients harboring different mutations on the dystrophin gene (DMD1, with a stop codon mutation on exon 59 and DMD2, a patient carrying a 48-50 deletion), with the main aim to carry on an independent validation on the suitability of the approach for phenotypic profiling. The results highlighted key differences in muscle functionality between healthy and dystrophic tissues, particularly in their ability to generate force and resist fatigue over time. However, these differences attenuated over time upon maintenance of a physiological environment and the absence of continuous nerve-like stimulation, suggesting that the main alteration resides in a delay of myogenic program. Given the role of dystrophin and the known aggravating factors in the presentation and progression of DMD, contraction stress and/or an inflammatory environment may be necessary to unveil dystrophic-related alterations in structure and function of the 3D muscle organoids, in order to reproduce more closely the patients’ pathology.