2015 Journal of tissue engineering and regenerative medicine
* Inducing endoderm differentiation by modulating mechanical properties of soft substrates.
- Early embryonic stem cell (ESC) differentiation is marked by the formation of three germ layers from which all tissues types arise. Conventionally, ESCs are differentiated by altering their chemical microenvironment. Recently however, it was established that a mechanical microenvironment can also contribute towards cellular phenotype commitment. In this study, we report how the cellular mechanical microenvironment of soft substrates affects the differentiation and phenotypic commitment of ESCs. Mouse ESCs were cultured in a fibrin hydrogel matrix in 2D and 3D cultures. The gelation characteristics of the substrates were modulated by systematically altering the fibrinogen concentration and the fibrinogen-thrombin crosslinking ratio. Analysis of the ESCs cultured on different substrate conditions clearly illustrated the strong influence that substrate physical characteristics assert on cellular behaviours. Specifically, it was found that ESCs had a higher proliferation rate in gels of lower stiffness. Early differentiation events were studied by analyzing the gene and protein expression levels of early germ layer markers. Our results revealed that lower substrate stiffness elicited stronger upregulation of endoderm related genes Sox17, Afp and Hnf4 compared to stiffer substrates. While both 2D and 3D cultures showed a similar response, the effects were much stronger in 3D culture. These results suggest that physical cues can be used to modulate ESC differentiation into clinically relevant tissues such as liver and pancreas.
=>表現すること, 式, 表現, 表示, 言い回し, 表現法, 表情
Overview of noun expression
The noun expression has 9 senses (first 6 from tagged texts)
1. (23) expression, look, aspect, facial expression, face -- (the feelings expressed on a person's
face; "a sad expression"; "a look of triumph"; "an angry face")
2. (18) expression, manifestation, reflection, reflexion -- (expression without words; "tears are an
expression of grief"; "the pulse is a reflection of the heart's condition")
3. (15) expression, verbal expression, verbalism -- (the communication (in speech or writing) of
your beliefs or opinions; "expressions of good will"; "he helped me find verbal expression for my
ideas"; "the idea was immediate but the verbalism took hours")
4. (5) saying, expression, locution -- (a word or phrase that particular people use in particular
situations; "pardon the expression")
5. (4) formulation, expression -- (the style of expressing yourself; "he suggested a better
formulation"; "his manner of expression showed how much he cared")
6. (4) formula, expression -- (a group of symbols that make a mathematical statement)
7. expression -- ((genetics) the process of expressing a gene)
8. construction, grammatical construction, expression -- (a group of words that form a constituent
of a sentence and are considered as a single unit; "I concluded from his awkward constructions that
he was a foreigner")
9. expression -- (the act of forcing something out by squeezing or pressing; "the expression of milk
from her breast")
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