Advanced Treatments and Emerging Therapies for Dystrophin- Deficient Cardiomyopathies

Dystrophinopathies are characterized by skeletal and cardiac muscle complications because of a lack or shortened DYSTROPHIN protein. Ventilation assistance and corticosteroid treatment have positively affected life outcome but lead to an increased incidence of cardiomyopathy. Cardiomyopathy is now the leading cause of death in patients with dystrophinopathy. Thus, coherent guidelines for cardiac care have become essential and need to be communicated well. Progression of cardiac complications in patients with dystrophinopathy diverges from standard dilated cardiomyopathy development and monitoring and medical care for dystrophinopathy. This chapter summarizes current guidelines and recommendations for monitoring and clinical treatment of cardiac complications in patients with dystrophinopathy and provides a thorough survey of emerging therapies focusing on cardiac outcomes

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 is incurable. The major cause of death is dilated cardiomyopathy however, its 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 induced pluripotent stem cells (DMD-COs) and isogenic-corrected controls (DMD-Iso-COs) 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-COs lack initial proliferative capacity, displayed a progressive loss of sarcoglycan localization and high stress in endoplasmic reticulum. Additionally, cardiomyocyte deterioration, fibrosis and aberrant adipogenesis were observed in DMD-COs over time. RNA sequencing analysis confirmed a distinct transcriptomic profile in DMD-COs which was 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

Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes to Model Chronic Cardiac Disorders

Cardiomyopathy is a leading cause of death in patients affected by Alström syndrome (ALMS) and Duchenne muscular dystrophy (DMD). Both disorders have a genetic origin, caused by mutations in the ALMS1 and DMD gene, respectively. Despite intense research, their precise pathologic function remains unclear. With the discovery of human embryonic (ESCs) and induced pluripotent stem cells (iPSCs) efforts have been made towards directing stem cell differentiation to the cardiovascular lineage. The generation of cardiovascular cells from human pluripotent stem cells (PSCs) provides a renewable source of human cardiomyocytes (CMs) to model heart-associated disorders in vitro. Moreover, PSCs hold potential for other clinical applications, including drug screening and toxicity testing as well as regenerative medicine. However, a major obstacle to more extensive use is their immature phenotype. Here, we described cardiac differentiation strategies from human PSCs to obtain more mature CMs for disease modeling purposes. Through the addition of Activin A (ActA) during early cardiac induction, we induced an endodermal-like cell subpopulation, which enhanced the early maturation state of PSC-derived CMs (PSC-CMs), probably through CRIPTO-1 signaling. Interestingly, this ActA-induced embryoid body (EB)-based CM differentiation model could reveal a persistent proliferation activity of postnatal CMs, suggesting defects in the CM cell cycle of ALMS patients with certain ALMS1 gene mutations. Moreover, via CRISPR/Cas9 gene editing, we could correct the genetic mutation, restoring ALMS1 protein expression levels and consequently rehabilitate the mitogenic cardiomyopathy in ALMS iPSC-CMs. Another strategy to increase the maturity of iPSC-CMs is to further differentiate them embedded in an extracellular matrix (ECM), mimicking the tissue-like environment. We developed human three-dimensional (3D) engineered heart tissue (EHT) constructs to address cardiomyopathy-related disease mechanisms in the DMD pathology, given that dystrophin (DYS) has a structural and signaling function in the heart. First, we addressed a more immature phenotype within iPSC-CMs that were differentiated in a classical two-dimensional (2D) monolayer protocol compared to iPSC-CMs that were further matured in a 3D differentiation environment. Secondly, we confirmed and identified potential mediators in DMD-induced cardiomyopathy, showing significantly dysregulated RNA transcripts. In conclusion, we described 3D EB and EHT cardiac differentiation systems from iPSCs isolated from ALMS and DMD patients to obtain more mature CMs. Our stem cell-based models could be of high interest to elucidate disease mechanisms, eventually pointing out novel therapeutic targets to ameliorate or tackle disease onset or progression.CHAPTER 1. INTRODUCTION & AIMS CHAPTER 2. ACTIVIN A MODULATES CRIPTO-1/HNF4α CELLS TO GUIDE CARDIAC DIFFERENTIATION FROM HUMAN EMBRYONIC STEM CELLS CHAPTER 3. MODELING ALSTRÖM SYNDROME-ASSOCIATED CARDIOMYOPATHY: “A DEAF HEART” PROMOTED PROLIFERATION CHAPTER 4. A THREE-DIMENSIONAL TISSUE ENGINEERED HUMAN INDUCED PLURIPOTENT STEM CELL MODEL TO STUDY DYSTROPHIC CARDIOMYOPATHY CHAPTER 5. SUMMARY, GENERAL DISCUSSION & FUTURE PERSPECTIVES CHAPTER 6. NEDERLANDSE SAMENVATTINGnrpages: 260status: publishe

Stem Cell Technology in Cardiac Regeneration: A Pluripotent Stem Cell Promise

Despite advances in cardiovascular biology and medical therapy, heart disorders are the leading cause of death worldwide. Cell-based regenerative therapies become a promising treatment for patients affected by heart failure, but also underline the need for reproducible results in preclinical and clinical studies for safety and efficacy. Enthusiasm has been tempered by poor engraftment, survival and differentiation of the injected adult stem cells. The crucial challenge is identification and selection of the most suitable stem cell type for cardiac regenerative medicine. Human pluripotent stem cells (PSCs) have emerged as attractive cell source to obtain cardiomyocytes (CMs), with potential applications, including drug discovery and toxicity screening, disease modelling and innovative cell therapies. Lessons from embryology offered important insights into the development of stem cell-derived CMs. However, the generation of a CM population, uniform in cardiac subtype, adult maturation and functional properties, is highly recommended. Moreover, hurdles regarding tumorigenesis, graft cell death, immune rejection and arrhythmogenesis need to be overcome in clinical practice. Here we highlight the recent progression in PSC technologies for the regeneration of injured heart. We review novel strategies that might overcome current obstacles in heart regenerative medicine, aiming at improving cell survival and functional integration after cell transplantation.publisher: Elsevier articletitle: Stem Cell Technology in Cardiac Regeneration: A Pluripotent Stem Cell Promise journaltitle: EBioMedicine articlelink: http://dx.doi.org/10.1016/j.ebiom.2017.01.029 content_type: article copyright: © 2017 Published by Elsevier B.V.status: publishe

Stem Cell Technology in Cardiac Regeneration: A Pluripotent Stem Cell Promise

Despite advances in cardiovascular biology and medical therapy, heart disorders are the leading cause of death worldwide. Cell-based regenerative therapies become a promising treatment for patients affected by heart failure, but also underline the need for reproducible results in preclinical and clinical studies for safety and efficacy. Enthusiasm has been tempered by poor engraftment, survival and differentiation of the injected adult stem cells. The crucial challenge is identification and selection of the most suitable stem cell type for cardiac regenerative medicine. Human pluripotent stem cells (PSCs) have emerged as attractive cell source to obtain cardiomyocytes (CMs), with potential applications, including drug discovery and toxicity screening, disease modelling and innovative cell therapies. Lessons from embryology offered important insights into the development of stem cell-derived CMs. However, the generation of a CM population, uniform in cardiac subtype, adult maturation and functional properties, is highly recommended. Moreover, hurdles regarding tumorigenesis, graft cell death, immune rejection and arrhythmogenesis need to be overcome in clinical practice. Here we highlight the recent progression in PSC technologies for the regeneration of injured heart. We review novel strategies that might overcome current obstacles in heart regenerative medicine, aiming at improving cell survival and functional integration after cell transplantation

In the heart of the in vivo reprogramming.

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Pluripotent Stem Cells for Treating Heart Diseases

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Methotrexate and Valproic Acid Affect Early Neurogenesis of Human Amniotic Fluid Stem Cells from Myelomeningocele

Myelomeningocele (MMC) is a severe type of neural tube defect (NTD), in which the backbone and spinal canal do not close completely during early embryonic development. This condition results in serious morbidity and increased mortality after birth. Folic acid significantly reduces, and conversely, folate antagonist methotrexate (MTX) and valproic acid (VPA) increase the occurrence of NTDs, including MMC. How these pharmacological agents exactly influence the early neurulation process is still largely unclear. Here, we characterized human amniotic fluid-derived stem cells (AFSCs) from prenatally diagnosed MMC and observed an effect of MTX and VPA administration on the early neural differentiation process. We found that MMC-derived AFSCs highly expressed early neural and radial glial genes that were negatively affected by MTX and VPA exposure. In conclusion, we setup a human cell model of MMC to study early neurogenesis and for drug screening purposes. We also proposed the detection of early neural gene expression in AFSCs as an additional MMC diagnostic tool