Highly contractile 3D tissue engineered skeletal muscles from human iPSCs reveal similarities with primary myoblast-derived tissues

Dynamic and Static Workout of In Vitro Skeletal Muscle Tissue through a Weight Training Device

Enhancing muscle strength through workouts is a key factor in improving physical activity and maintaining metabolic profiles. The controversial results concerning the impacts of weight training often arise from clinical experiments that require controlled experimental conditions. In this study, a weight training system for a muscle development model is presented, which is capable of performing weight training motions with adjustable weight loads. Through the implementation of cultured skeletal muscle tissue with floating structures and a flexible ribbon, both isotonic (dynamic change in muscle length) and isometric (static in muscle length) exercises can be performed without the deflection of the tissue. Quantitative analysis of contraction force, changes in metabolic processes, and muscle morphology under different weight training conditions demonstrates the effectiveness of the proposed system. Our proposed system holds potential for establishing effective muscle development and for further applications in rehabilitation training methods.

A knock down strategy for rapid, generic, and versatile modelling of muscular dystrophies in 3D-tissue-engineered-skeletal muscle

BACKGROUND

Human iPSC-derived 3D-tissue-engineered-skeletal muscles (3D-TESMs) offer advanced technology for disease modelling. However, due to the inherent genetic heterogeneity among human individuals, it is often difficult to distinguish disease-related readouts from random variability. The generation of genetically matched isogenic controls using gene editing can reduce variability, but the generation of isogenic hiPSC-derived 3D-TESMs can take up to 6 months, thereby reducing throughput.

METHODS

Here, by combining 3D-TESM and shRNA technologies, we developed a disease modelling strategy to induce distinct genetic deficiencies in a single hiPSC-derived myogenic progenitor cell line within 1 week.

RESULTS

As proof of principle, we recapitulated disease-associated pathology of Duchenne muscular dystrophy and limb-girdle muscular dystrophy type 2A caused by loss of function of DMD and CAPN3, respectively. shRNA-mediated knock down of DMD or CAPN3 induced a loss of contractile function, disruption of tissue architecture, and disease-specific proteomes. Pathology in DMD-deficient 3D-TESMs was partially rescued by a candidate gene therapy treatment using micro-dystrophin, with similar efficacy compared to animal models.

CONCLUSIONS

These results show that isogenic shRNA-based humanized 3D-TESM models provide a fast, cheap, and efficient tool to model muscular dystrophies and are useful for the preclinical evaluation of novel therapies.

Generation of Human-Induced Pluripotent Stem Cells from Peripheral Blood Mononuclear Cells of C9ORF72-Associated Amyotrophic Lateral Sclerosis Patients

Disease modeling of neuromuscular disorders, such as amyotrophic lateral sclerosis (ALS), is hindered by limited accessibility of affected cells. This problem can be overcome by generation of human induced pluripotent stem cells (hiPSC), which can be then differentiated into required cells. Here, we describe the detailed protocol of hiPSC establishment from peripheral blood mononuclear cells (PBMC) of two ALS patients with detected expansion of G4C2 (GGGGCC) repeats in the first intron of C9ORF72 gene, known to be linked with the most common form of familial ALS.Successful PBMC reprogramming with non-integrating Sendai vectors was confirmed by expression of pluripotency markers: OCT4, NANOG, SSEA4, and TRA-1-60 in obtained hiPSC and their ability to differentiate into cells of three germ layers.The generated ALS-patient-specific hiPSC create a possibility for deciphering molecular basis of this devastating neuromuscular disease.