title: Image-based quantification and mathematical modeling of spatial heterogeneity in ESC colonies.
abstract: Pluripotent embryonic stem cells (ESCs) have the potential to differentiate into cells of all three germ layers. This unique property has been extensively studied on the intracellular, transcriptional level. However, ESCs typically form clusters of cells with distinct size and shape, and establish spatial structures that are vital for the maintenance of pluripotency. Even though it is recognized that the cells' arrangement and local interactions play a role in fate decision processes, the relations between transcriptional and spatial patterns have not yet been studied. We present a systems biology approach which combines live-cell imaging, quantitative image analysis, and multiscale, mathematical modeling of ESC growth. In particular, we develop quantitative measures of the morphology and of the spatial clustering of ESCs with different expression levels and apply them to images of both in vitro and in silico cultures. Using the same measures, we are able to compare model scenarios with different assumptions on cell-cell adhesions and intercellular feedback mechanisms directly with experimental data. Applying our methodology to microscopy images of cultured ESCs, we demonstrate that the emerging colonies are highly variable regarding both morphological and spatial fluorescence patterns. Moreover, we can show that most ESC colonies contain only one cluster of cells with high self-renewing capacity. These cells are preferentially located in the interior of a colony structure. The integrated approach combining image analysis with mathematical modeling allows us to reveal potential transcription factor related cellular and intercellular mechanisms behind the emergence of observed patterns that cannot be derived from images directly.
authors.affiliation: Institute for Medical Informatics and Biometry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Herberg
authors.affiliation: Institute for Medical Informatics and Biometry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zerjatke
authors.affiliation: Center for Information Services and High Performance Computing, Technische Universität Dresden, Dresden, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: de Back
authors.affiliation: Institute for Medical Informatics and Biometry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Glauche
authors.affiliation: Institute for Medical Informatics and Biometry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Roeder
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002454:Cell Differentiation; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D019295:Computational Biology / Q000379:methods; D003198:Computer Simulation; D003470:Culture Media / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D053605:Leukemia Inhibitory Factor / Q000494:pharmacology; D051379:Mice; D008856:Microscopy, Fluorescence; D008962:Models, Theoretical; D039904:Pluripotent Stem Cells / Q000166:cytology*; D049490:Systems Biology / Q000379:methods
chemical_list: D003470:Culture Media; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse
keywords: cell-cell interactions; embryonic stem cells; image quantification; quantitative measures; spatial modeling; transcription factor heterogeneity