Helmholtz-Institute for Biomedical Engineering, Division of Stem Cell Biology
Mechanostimulation to direct differentiation of iPSCs and iPSC-derived embryoid bodies.
Project overview. We investigate self-organization of aggregates of iPSCs – so called embryoid bodies – and the impact of hydrogels and mechanical stimulation on their differentiation. (A) Phase contrast images of a self-detaching iPSC colony from vitronectin micro-contact printed substrates. (B) DNA methylation biomarkers to quantify differentiation toward endoderm, mesoderm and ectoderm. (C) Immunofluorescence images of iPSC differentiation in the different hydrogels. IPSCs are stained for DAPI and Phalloidin488 and the lineage specific markers GATA6 (endoderm), Brachyury (mesoderm), and PAX6 (ectoderm).
Institute of Biological Information Processing (IBI-2): Mechanobiology, Forschungszentrum Jülich
Breast gland development and cell invasion in strained microenvironments
Project overview. Workflow to elucidate strain-induced mechanotransduction circuits in normal breast gland and cancer development.
Institute of Molecular and Cellular Anatomy (MOCA), Uniklinik RWTH Aachen
Mechanobiology of human embryo implantation
Project overview. (A) The scheme highlights details of endometrial differentiation during the window of implantation. The junctional complex is redistributed from its apicolateral position to the entire lateral cell border. The apical microvillar brush border is reduced and actin-rich protrusions, so called pinopodes, are formed. The underlying connective tissue compartment is also profoundly changed referred to as decidualization, which includes mesenchymal to epithelial transition of resident fibroblasts into decidual cells and changes in composition and biomechanics of the extracellular matrix. The embryo responds to the contact with the endometrium by increased osmotic pressure and thereby compresses the adjacent endotmetrial epithelium. (B) The traction force plots of endometrial epithelial Ishikawa cell monolayers growing on soft 4 kPa substrates reveal differences in the absence and presence of hormones (E2, estradiol; MPA, medroxyprogesterone acetate). (C) Dispase adhesion assays detect differences in the mechanical stress response in three endometrial epithelial cell lines with different degrees of polarization. (D) The scheme and microscopy image illustrate the workflow to produce standardized, single cell-derived trophoblast spheroids (green) for adhesion tests on endometrial epithelial cell (EEC) monolayers of different origin growing under defined hormonal and mechanophysical conditions.
PULS Group, Institute for Theoretical Physics, FAU Erlangen
Toward quantitative modeling and simulations of structure formation in epithelium – relating tissue topology and homeostasis
Project overview. Quantitative analysis and modeling of interaction of epithelial tissues and the environment. (A) An example of experiments for stretching a colony of MDCK cells. (B) Analysis of experimental images with well-established methods to follow individual cells and quantify different properties of cells such as distribution of cell area as plotted here. (C) Continuum models developed to describe the dynamics of the spatial profile of cell density (n) with cell velocity (v) and active terms (k). The results fit very well with the colony growth experiments. (D) Simulation of growth and stretching of tissues at the level of individual cells (vertex model).
