Protein Detection in Blood with Single-Molecule Imaging

Abstract

drug discovery is their immature state relative to the adult myocardium. In this research, 3D cardiac microtissues (CMTs) were generated using hiPSC-CMs to recapitulate the structural, functional and metabolic properties of normal and diseased adult ventricular myocardium. CMTs were treated with ontologically defined biochemical interventions (thyroid hormone, dexamethasone and insulin-like growth factor, TDI) to promote the maturation of hiPSC-CMs. The effects of TDI treatment on both structural and functional (biomechanical, Ca2þ handling and electrophysiology) properties at the tissue level were characterized. Also, the molecular correlates of maturation of the hiPSC-CMs in the CMTs were studied by gene expression, proteomics studies. Our data demonstrate that TDI treatment improves both the structure and function of CMTs. Structurally, the hiPSC-CMs show improved alignment and longer sarcomere length, as shown by immunofluorescence and confocal microscopy. Functionally, CMTs' static and dynamic force both increase following TDI treatment, and cardiac electrophysiology assessed by optical mapping showing that the CMTs are electrically coupled. TDI-treated CMTs exhibited both chronotropic and inotropic response to isoproterenol treatment. The enhanced functional properties that this maturation approach yields have the potential to yield improved hiPSC derived cardiac model systems that can advance both mechanistic studies and the development of new therapies for the treatment of cardiac diseases.