Pozzo, E. | Search bioRxiv

bioRxiv2022

Long-Term Culture of Patient-Derived Cardiac Organoids Recapitulated Duchenne Muscular Dystrophy Cardiomyopathy and Disease Progression

Duchenne Muscular Dystrophy (DMD) is an X-linked neuromuscular disease which to-date incurable. The major cause of death is dilated cardiomyopathy, however the pathogenesis is unclear as existing cellular and animal models do not fully recapitulate the human disease phenotypes. In this study, we generated cardiac organoids from patient-derived pluripotent stem cells (DMD-CO) and isogenic-corrected controls (DMD-Iso-CO) and studied if DMD-related cardiomyopathy and disease progression occur in the organoids upon long-term culture (up to 93 days). Histological analysis showed that DMD-CO lacks initial proliferative capacity, displayed a progressive loss of -sarcoglycan localization and high stress in endoplasmic reticulum. Additionally, the cardiomyocyte deteriorated over time, and fibrosis and adipogenesis were observed in DMD-CO. RNA sequencing analysis confirmed a distinct transcriptomic profile in DMD-CO which were associated with functional enrichment in hypertrophy/dilated cardiomyopathy, arrhythmia, adipogenesis and fibrosis pathways. Moreover, five miRNAs were identified to be crucial in this dysregulated gene network. In conclusion, we generated patient-derived cardiac organoid model that displayed DMD-related cardiomyopathy and disease progression phenotypes in long-term culture. We envision the feasibility to develop a more complex, realistic and reliable in vitro 3D human cardiac-mimics to study DMD-related cardiomyopathies.

cell biology↗

bioRxiv2021

MyoD-Cre driven alterations in K-Ras and p53 lead to a mouse model with histological and molecular characteristics of human rhabdomyosarcoma with direct translational applications

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, with overall long-term survival rates of about 65-70%. Thus, additional molecular insights and representative models are critical for further identifying and evaluating new treatment modalities. Using MyoD-Cre mediated introduction of mutant K-RasG12D and perturbations in p53 we have developed a novel genetically engineered mouse model (GEMM) for RMS. Specifically, we directly crossed mice expressing MyoD promoter-regulated Cre-recombinase with germline p53Flox or Lox-Stop-Lox (LSL) knock-in alleles expressing oncogenic p53R172H and/or K-RasG12D mutants. The anatomic sites of primary RMS development observed in these mice recapitulated human disease, with the most frequent sites of tumor growth seen in the head, neck, extremities, and abdomen. We have confirmed RMS histology and diagnosis through hematoxylin and eosin (H&E) staining, as well as positive immunohistochemistry (IHC) staining for desmin, myogenin, and phosphotungstic acid hematoxylin (PTAH). We established cell lines from several of the GEMM tumors with the ability to engraft and develop tumors in immunocompetent mice with similar histological and staining features as the primary tumors. Furthermore, injection of syngeneic RMS lines via tail vein had high metastatic potential to the lungs. Transcriptomic analyses of p53R172H/K-RasG12D GEMM-derived tumors showed evidence of high molecular homology with human RMS. Specifically, we noted alterations in gene ontologies including immune response, metabolism and mRNA processing. Finally, pre-clinical use of these murine RMS lines demonstrated similar therapeutic responsiveness to relevant chemotherapy and targeted therapies as human cell line models. Summary StatementWe have developed a new conditional genetically engineered mouse model of rhabdomyosarcoma (RMS) with homologous molecular signature to human RMS that provides valuable pre-clinical models for evaluating novel therapies.

cancer biology↗