title: Differential regulation of morphology and stemness of mouse embryonic stem cells by substrate stiffness and topography.
abstract: The maintenance of stem cell pluripotency or stemness is crucial to embryonic development and differentiation. The mechanical or physical microenvironment of stem cells, which includes extracellular matrix stiffness and topography, regulates cell morphology and stemness. Although a growing body of evidence has shown the importance of these factors in stem cell differentiation, the impact of these biophysical or biomechanical regulators remains insufficiently characterized. In the present study, we applied a micro-fabricated polyacrylamide hydrogel substrate with two elasticities and three topographies to systematically test the morphology, proliferation, and stemness of mESCs. The independent or combined impact of the two factors on specific cell functions was analyzed. Cells are able to grow effectively on both polystyrene and polyacrylamide substrates in the absence of feeder cells. Substrate stiffness is predominant in preserving stemness by enhancing Oct-4 and Nanog expression on a soft polyacrylamide substrate. Topography is also a critical factor for manipulating stemness via the formation of a relatively flattened colony on a groove or pillar substrate and a spheroid colony on a hexagonal substrate. Although topography is less effective on soft substrates, it plays a role in retaining cell stemness on stiff, hexagonal or pillar-shaped substrates. mESCs also form, in a timely manner, a 3D structure on groove or hexagonal substrates. These results further the understanding of stem cell morphology and stemness in a microenvironment that mimics physiological conditions.
authors: Center of Biomechanics and Bioengineering and Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Dongyuan
authors: D
authors: Lü
authors: Center of Biomechanics and Bioengineering and Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Chunhua
authors: C
authors: Luo
authors: Center of Biomechanics and Bioengineering and Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Chen
authors: C
authors: Zhang
authors: Center of Biomechanics and Bioengineering and Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
authors: Zhan
authors: Z
authors: Li
authors: Center of Biomechanics and Bioengineering and Key Laboratory of Microgravity (National Microgravity Laboratory), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: mlong@imech.ac.cn.
authors: Mian
authors: M
authors: Long
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D049109:Cell Proliferation / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism
chemical_list: D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3
keywords: Morphology; Stem cell; Stemness; Stiffness; Topography