TY - JOUR
T1 - Endogenous production of fibronectin is required for self-renewal of cultured mouse embryonic stem cells
AU - Hunt, Geoffrey C.
AU - Singh, Purva
AU - Schwarzbauer, Jean E.
N1 - Funding Information:
We would like to thank Drs. Ihor Lemischka, Christoph Schaniel, and Jane Sottile for helpful advice and reagents, Tina deCoste and the Molecular Biology Department Flow Cytometry Facility for help with FACS analyses, and Leah Owens and Cara Carraher for comments on the manuscript. This research was funded by the National Institutes of Health CA044627 and GM059383 (to J.E.S.), NIH Predoctoral Training Grant CA009528 , and a predoctoral fellowship from the New Jersey Commission on Spinal Cord Research (to G.C.H.).
PY - 2012/9/10
Y1 - 2012/9/10
N2 - Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture.
AB - Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture.
KW - Embryonic stem cell
KW - Extracellular matrix
KW - Fibronectin
KW - Integrin
KW - Self-renewal
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U2 - 10.1016/j.yexcr.2012.06.009
DO - 10.1016/j.yexcr.2012.06.009
M3 - Article
C2 - 22710062
AN - SCOPUS:84863775290
SN - 0014-4827
VL - 318
SP - 1820
EP - 1831
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 15
ER -