Key result
Stiff laminin surfaces drive mature β-MyHC expression in human pluripotent stem cell-derived cardiomyocytes.
Maturation of human embryonic stem cell-derived cardiomyocytes into an adult ventricular phenotype requires multiple distinct stimuli, as β-MyHC expression is driven by substrate stiffness while MLC2v expression depends more on growth factors.
Answers are grounded in this paper and cite their sources.
Substrate-matrix effects on hESC-CM maturation warrant caution before clinical use; leaves open optimal combinations for adult ventricular phenotype.
To fully exploit the potential of human pluripotent stem cell-derived cardiomyocytes, ideally they should acquire a mature, adult ventricular-like phenotype. Predominant expression of the β-isoform of myosin heavy chain (β-MyHC) and the ventricular isoform of myosin regulatory light chain 2 (MLC2v) is a marker of human adult cardiac ventricle. Yet predominant co-expression of these isoforms is rarely reported by current culture protocols. Here, we assessed the impact of different substrates on β-MyHC and MLC2v expression in single human embryonic stem cell-derived CMs (hESC-CMs). As substrates, surface materials with differing stiffness as defined by Young’s modulus were combined with either laminin, a single-component coating, or Matrigel, a multi-component coating including growth factors. Semi-quantitative single-cell immunofluorescence analysis demonstrated that surfaces with supraphysiological stiffness in combination with laminin are sufficient for promotion of predominant β-MyHC expression, but not for predominant MLC2v expression in hESC-CMs. Accordingly, mechanical stimuli likely promote expression of β-MyHC in these cultures. Culture on matrices with a lower stiffness than glass in combination with growth factor-containing Matrigel led to only moderate increases in MLC2v expression, possibly more dependent on growth factors, suggesting different regulation of expression. Integrin-related downstream signal transducers, integrin-linked and cardiac troponin I-interacting kinase, as well as modulation of intracellular Ca 2+ -concentration and epigenetic signaling did not affect MyHC/MLC2 isoform expression. The data indicate that expression of adult ventricular markers β-MyHC and MLC2v depends on different stimuli like substrate stiffness and growth factors. To conclude, multiple stimuli appear to be necessary to promote an adult ventricular phenotype.
No takes yet. Share an insight, caveat, or question.
Osten et al. (2025) studied In vitro human embryonic stem cell-derived cardiomyocytes. Substrate stiffness and coating (laminin vs Matrigel) vs. Different substrate combinations was evaluated on Proportion of exclusively β-MyHC and MLC2v expressing cells. Surfaces with supraphysiological stiffness combined with laminin promoted predominant β-MyHC expression, while lower stiffness matrices with Matrigel moderately increased MLC2v expression in hESC-CMs.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: