Strengthening cardiac therapy pipelines using human pluripotent stem cell-derived cardiomyocytes

Advances in hiPSC isolation and reprogramming and hPSC-CM differentiation have prompted their therapeutic application and utilization for evaluating potential cardiovascular safety liabilities. In this perspective, we showcase key efforts toward the large-scale production of hiPSC-CMs, implementation of hiPSC-CMs in industry settings, and recent clinical applications of this technology. The key observations are a need for traceable gender and ethnically diverse hiPSC lines, approaches to reduce cost of scale-up, accessible clinical trial datasets, and transparent guidelines surrounding the safety and efficacy of hiPSC-based therapies.

Cardiovascular Functions of Ena/VASP Proteins: Past, Present and Beyond

Actin binding proteins are of crucial importance for the spatiotemporal regulation of actin cytoskeletal dynamics, thereby mediating a tremendous range of cellular processes. Since their initial discovery more than 30 years ago, the enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) family has evolved as one of the most fascinating and versatile family of actin regulating proteins. The proteins directly enhance actin filament assembly, but they also organize higher order actin networks and link kinase signaling pathways to actin filament assembly. Thereby, Ena/VASP proteins regulate dynamic cellular processes ranging from membrane protrusions and trafficking, and cell-cell and cell-matrix adhesions, to the generation of mechanical tension and contractile force. Important insights have been gained into the physiological functions of Ena/VASP proteins in platelets, leukocytes, endothelial cells, smooth muscle cells and cardiomyocytes. In this review, we summarize the unique and redundant functions of Ena/VASP proteins in cardiovascular cells and discuss the underlying molecular mechanisms.

Membranes for Modelling Cardiac Tissue Stiffness In Vitro Based on Poly(trimethylene carbonate) and Poly(ethylene glycol) Polymers

Despite the increased expenditure of the pharmaceutical industry on research and development, the number of drugs for cardiovascular diseases that reaches the market is decreasing. A major issue is the limited ability of the current in vitro and experimental animal models to accurately mimic human heart disease, which hampers testing of the efficacy of potential cardiac drugs. Moreover, many non-heart-related drugs have severe adverse cardiac effects, which is a major cause of drugs’ retraction after approval. A main hurdle of current in vitro models is their inability to mimic the stiffness of in vivo cardiac tissue. For instance, poly(styrene) petri dishes, which are often used in these models, have a Young’s modulus in the order of GPa, while the stiffness of healthy human heart tissue is <50 kPa. In pathological conditions, such as scarring and fibrosis, the stiffness of heart tissue is in the >100 kPa range. In this study, we focus on developing new membranes, with a set of properties for mimicry of cardiac tissue stiffness in vitro, based on methacrylate-functionalized macromers and triblock-copolymers of poly(trimethylene carbonate) and poly(ethylene glycol). The new membranes have Young’s moduli in the hydrated state ranging from 18 kPa (healthy tissue) to 2.5 MPa (pathological tissue), and are suitable for cell contraction studies using human pluripotent stem-cell-derived cardiomyocytes. The membranes with higher hydrophilicity have low drug adsorption and low Young’s moduli and could be suitable for drug screening applications.

Unlocking Personalized Biomedicine and Drug Discovery with Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Fit for Purpose or Forever Elusive?

In recent decades, drug development costs have increased by approximately a hundredfold, and yet about 1 in 7 licensed drugs are withdrawn from the market, often due to cardiotoxicity. This review considers whether technologies using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) could complement existing assays to improve discovery and safety while reducing socioeconomic costs and assisting with regulatory guidelines on cardiac safety assessments. We draw on lessons from our own work to suggest a panel of 12 drugs that will be useful in testing the suitability of hiPSC-CM platforms to evaluate contractility. We review issues, including maturity versus complexity, consistency, quality, and cost, while considering a potential need to incorporate auxiliary approaches to compensate for limitations in hiPSC-CM technology. We give examples on how coupling hiPSC-CM technologies with Cas9/CRISPR genome engineering is starting to be used to personalize diagnosis, stratify risk, provide mechanistic insights, and identify new pathogenic variants for cardiovascular disease.