Substrate elasticity does not impact DNA methylation changes during differentiation of pluripotent stem cells.

Background Aims: Substrate elasticity may direct cell-fate decisions of stem cells. However, it is largely unclear how matrix stiffness affects the differentiation of induced pluripotent stem cells (iPSCs) and whether this is also reflected by epigenetic modifications.

Methods: We cultured iPSCs on tissue culture plastic (TCP) and polydimethylsiloxane (PDMS) with different Young's modulus (0.

CTCF deletion alters the pluripotency and DNA methylation profile of human iPSCs.

Pluripotent stem cells are characterized by their differentiation potential toward endoderm, mesoderm, and ectoderm. However, it is still largely unclear how these cell-fate decisions are mediated by epigenetic mechanisms. In this study, we explored the relevance of CCCTC-binding factor (CTCF), a zinc finger-containing DNA-binding protein, which mediates long-range chromatin organization, for directed cell-fate determination.

YAP1 is essential for self-organized differentiation of pluripotent stem cells.

Induced pluripotent stem cells (iPSCs) form aggregates that recapitulate aspects of the self-organization in early embryogenesis. Within few days, cells undergo a transition from epithelial-like structures to organized three-dimensional embryoid bodies (EBs) with upregulation of germ layer-specific genes. However, it is largely unclear, which signaling cascades regulate self-organized differentiation.

Epigenetic biomarkers to track differentiation of pluripotent stem cells.

Quality control of induced pluripotent stem cells remains a challenge. For validation of the pluripotent state, it is crucial to determine trilineage differentiation potential toward endoderm, mesoderm, and ectoderm. Here, we report GermLayerTracker, a combination of site-specific DNA methylation (DNAm) assays that serve as biomarker for early germ layer specification.

Cell Cluster Sorting in Automated Differentiation of Patient-specific Induced Pluripotent Stem Cells Towards Blood Cells.

Induced pluripotent stem cells (iPS cells) represent a particularly versatile stem cell type for a large array of applications in biology and medicine. Taking full advantage of iPS cell technology requires high throughput and automated iPS cell culture and differentiation. We present an automated platform for efficient and robust iPS cell culture and differentiation into blood cells.

The spatial self-organization within pluripotent stem cell colonies is continued in detaching aggregates.

Colonies of induced pluripotent stem cells (iPSCs) reveal aspects of self-organization even under culture conditions that maintain pluripotency. To investigate the dynamics of this process under spatial confinement, we used either polydimethylsiloxane (PDMS) pillars or micro-contact printing of vitronectin. There was a progressive upregulation of OCT4, E-cadherin, and NANOG within 70 μm from the outer rim of iPSC colonies.

Rational formulation design of injectable thermosensitive chitosan-based hydrogels for cell encapsulation and delivery.

This work reports a rational design of injectable thermosensitive chitosan systems for cell encapsulation and delivery. Using mixtures of two phosphate salts, beta-glycerophosphate and ammonium hydrogen phosphate, we demonstrate that the pH and the osmolarity can be adjusted separately by varying the molar ratios between the salts and the d-glucosamine monomers. We found the existence of a critical temperature above which gelation time decays following a power-law.

Cell Mechanics in Embryoid Bodies.

Embryoid bodies (EBs) resemble self-organizing aggregates of pluripotent stem cells that recapitulate some aspects of early embryogenesis. Within few days, the cells undergo a transition from rather homogeneous epithelial-like pluripotent stem cell colonies into a three-dimensional organization of various cell types with multifaceted cell-cell interactions and lumen formation-a process associated with repetitive epithelial-mesenchymal transitions. In the last few years, culture methods have further evolved to better control EB size, growth, cellular composition, and organization-e.