Generation of human induced pluripotent stem cell (hiPSC) lines derived from three patients carrying the pathogenic CRYAB (A527G) mutation and one non-carrier family member.

A newly identified pathogenic variant (A527G) in alpha B-crystallin (αB-crystallin) has been linked to congenital cataract and young-onset dilated cardiomyopathy (DCM) within a Dutch family, although the disease mechanism remains unclear. Four human induced pluripotent stem cell (hiPSC) clones were generated from three symptomatic patients carrying the A527G variant, and one healthy proband. Peripheral blood mononuclear cells (PBMCs) were reprogrammed using integration-free Sendai viral pluripotency vectors. The established hiPSCs clones exhibited regular ESC-like morphology, expression of pluripotency markers, and normal karyotyping. These hiPSC lines can facilitate future studies to understand the chaperone function and its role in DCM disease progression.

Generation, High-Throughput Screening, and Biobanking of Human-Induced Pluripotent Stem Cell-Derived Cardiac Spheroids.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are of paramount importance for human cardiac disease modeling and therapeutics. We recently published a cost-effective strategy for the massive expansion of hiPSC-CMs in two dimensions (2D). Two major limitations are cell immaturity and a lack of three-dimensional (3D) arrangement and scalability in high-throughput screening (HTS) platforms. To overcome these limitations, the expanded cardiomyocytes form an ideal cell source for the generation of 3D cardiac cell culture and tissue engineering techniques. The latter holds great potential in the cardiovascular field, providing more advanced and physiologically relevant HTS. Here, we describe an HTS-compatible workflow with easy scalability for the generation, maintenance, and optical analysis of cardiac spheroids (CSs) in a 96-well-format. These small CSs are essential to fill the gap present in current in vitro disease models and/or generation for 3D tissue engineering platforms. The CSs present a highly structured morphology, size, and cellular composition. Furthermore, hiPSC-CMs cultured as CSs display increased maturation and several functional features of the human heart, such as spontaneous calcium handling and contractile activity. By automatization of the complete workflow, from the generation of CSs to functional analysis, we increase intra- and inter-batch reproducibility as demonstrated by high-throughput (HT) imaging and calcium handling analysis. The described protocol allows modeling of cardiac diseases and assessing drug/therapeutic effects at the single-cell level within a complex 3D cell environment in a fully automated HTS workflow. In addition, the study describes a straightforward procedure for long-term preservation and biobanking of whole-spheroids, thereby providing researchers the opportunity to create next-generation functional tissue storage. HTS combined with long-term storage will substantially contribute to translational research in a wide range of areas, including drug discovery and testing, regenerative medicine, and the development of personalized therapies.