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Combinatorial fibronectin and laminin signaling promote highly efficient cardiac differentiation of human embryonic stem cells.

Sa S, Wong L, McCloskey KE - Biores Open Access (2014)

Bottom Line: Moreover, the LN receptor integrin β4 (ITGB4) and FN receptor integrin β5 (ITGB5) genes, jointly with increased phosphorylated focal adhension kinase and phosphorylated extracellular signal-regulated kinases (p-ERKs), were up-regulated over 13-fold in H7 and H9 cultured on 70:30 FN:LN compared with gelatin.Blocking studies confirmed the role of all these molecules in CM specification, suggesting that the 70:30 FN:LN ECM promotes highly efficient differentiation of CMs through the integrin-mediated MEK/ERK signaling pathway.Lastly, the data suggest that FN:LN-induced signaling utilizes direct cell-to-cell signaling from distinct ITGB4(+) and ITGB5(+) cells.

View Article: PubMed Central - PubMed

Affiliation: Graduate Group in Biological Engineering & Small-Scale Technologies, University of California , Merced, California.

ABSTRACT
Cardiomyocytes (CMs) differentiated from human embryonic stem cells (hESCs) are a promising and potentially unlimited cell source for myocardial repair and regeneration. Recently, multiple methodologies-primarily based on the optimization of growth factors-have been described for efficient cardiac differentiation of hESCs. However, the role of extracellular matrix (ECM) signaling in CM differentiation has not yet been explored fully. This study examined the role of ECM signaling in the efficient generation of CMs from both H7 and H9 ESCs. The hESCs were differentiated on ECM substrates composed of a range of fibronectin (FN) and laminin (LN) ratios and gelatin and evaluated by the fluorescence activated cell scanning (FACS) analysis on day 14. Of the ECM substrates examined, the 70:30 FN:LN reproducibly generated the greatest numbers of CMs from both hESC lines. Moreover, the LN receptor integrin β4 (ITGB4) and FN receptor integrin β5 (ITGB5) genes, jointly with increased phosphorylated focal adhension kinase and phosphorylated extracellular signal-regulated kinases (p-ERKs), were up-regulated over 13-fold in H7 and H9 cultured on 70:30 FN:LN compared with gelatin. Blocking studies confirmed the role of all these molecules in CM specification, suggesting that the 70:30 FN:LN ECM promotes highly efficient differentiation of CMs through the integrin-mediated MEK/ERK signaling pathway. Lastly, the data suggest that FN:LN-induced signaling utilizes direct cell-to-cell signaling from distinct ITGB4(+) and ITGB5(+) cells.

No MeSH data available.


Related in: MedlinePlus

Schematic drawing summarizing the mechanisms for ECM signaling in cardiomyocyte differentiation. The FN:LN ECM activates integrin, FAK, and MEK/ERK pathways, and in turn leads to the specification of cardiomyocyte differentiation from hESCs.
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f6: Schematic drawing summarizing the mechanisms for ECM signaling in cardiomyocyte differentiation. The FN:LN ECM activates integrin, FAK, and MEK/ERK pathways, and in turn leads to the specification of cardiomyocyte differentiation from hESCs.

Mentions: Because integrins and growth factors share common elements in their signaling pathways, there are many opportunities for integrin signals to modulate growth factor signals and for growth factors to modulate integrin signaling.56 Moreover, these activation pathways can be intercepted at a number of locations. For example, Raf activation is thought to be downstream of integrin-regulated p21-activated kinase, whereas MEK activation is downstream of integrin-regulated FAK.57,58 Combining current dogma on integrin signaling with our integrin data, a partial mechanism is proposed (Fig. 6). Integrin signaling on distinct cells begins with the clustering of dimeric (α,β) integrin receptors on distinct cells followed by induced recruitment of focal adhesion proteins (e.g., vinculin, paxillin, talin) and subsequent activation of integrin-associated signaling cascades, which among others, include such protein as FAK and src.59 Additional arrows are included because integrins can also intersect MAP kinase pathways at multiple points, including activation of Raf, activation of MEK, and nuclear translocation of Erk, thus enhancing or mitigating the effects of growth factor signaling, acting as genuine signaling receptors themselves.56


Combinatorial fibronectin and laminin signaling promote highly efficient cardiac differentiation of human embryonic stem cells.

Sa S, Wong L, McCloskey KE - Biores Open Access (2014)

Schematic drawing summarizing the mechanisms for ECM signaling in cardiomyocyte differentiation. The FN:LN ECM activates integrin, FAK, and MEK/ERK pathways, and in turn leads to the specification of cardiomyocyte differentiation from hESCs.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4120929&req=5

f6: Schematic drawing summarizing the mechanisms for ECM signaling in cardiomyocyte differentiation. The FN:LN ECM activates integrin, FAK, and MEK/ERK pathways, and in turn leads to the specification of cardiomyocyte differentiation from hESCs.
Mentions: Because integrins and growth factors share common elements in their signaling pathways, there are many opportunities for integrin signals to modulate growth factor signals and for growth factors to modulate integrin signaling.56 Moreover, these activation pathways can be intercepted at a number of locations. For example, Raf activation is thought to be downstream of integrin-regulated p21-activated kinase, whereas MEK activation is downstream of integrin-regulated FAK.57,58 Combining current dogma on integrin signaling with our integrin data, a partial mechanism is proposed (Fig. 6). Integrin signaling on distinct cells begins with the clustering of dimeric (α,β) integrin receptors on distinct cells followed by induced recruitment of focal adhesion proteins (e.g., vinculin, paxillin, talin) and subsequent activation of integrin-associated signaling cascades, which among others, include such protein as FAK and src.59 Additional arrows are included because integrins can also intersect MAP kinase pathways at multiple points, including activation of Raf, activation of MEK, and nuclear translocation of Erk, thus enhancing or mitigating the effects of growth factor signaling, acting as genuine signaling receptors themselves.56

Bottom Line: Moreover, the LN receptor integrin β4 (ITGB4) and FN receptor integrin β5 (ITGB5) genes, jointly with increased phosphorylated focal adhension kinase and phosphorylated extracellular signal-regulated kinases (p-ERKs), were up-regulated over 13-fold in H7 and H9 cultured on 70:30 FN:LN compared with gelatin.Blocking studies confirmed the role of all these molecules in CM specification, suggesting that the 70:30 FN:LN ECM promotes highly efficient differentiation of CMs through the integrin-mediated MEK/ERK signaling pathway.Lastly, the data suggest that FN:LN-induced signaling utilizes direct cell-to-cell signaling from distinct ITGB4(+) and ITGB5(+) cells.

View Article: PubMed Central - PubMed

Affiliation: Graduate Group in Biological Engineering & Small-Scale Technologies, University of California , Merced, California.

ABSTRACT
Cardiomyocytes (CMs) differentiated from human embryonic stem cells (hESCs) are a promising and potentially unlimited cell source for myocardial repair and regeneration. Recently, multiple methodologies-primarily based on the optimization of growth factors-have been described for efficient cardiac differentiation of hESCs. However, the role of extracellular matrix (ECM) signaling in CM differentiation has not yet been explored fully. This study examined the role of ECM signaling in the efficient generation of CMs from both H7 and H9 ESCs. The hESCs were differentiated on ECM substrates composed of a range of fibronectin (FN) and laminin (LN) ratios and gelatin and evaluated by the fluorescence activated cell scanning (FACS) analysis on day 14. Of the ECM substrates examined, the 70:30 FN:LN reproducibly generated the greatest numbers of CMs from both hESC lines. Moreover, the LN receptor integrin β4 (ITGB4) and FN receptor integrin β5 (ITGB5) genes, jointly with increased phosphorylated focal adhension kinase and phosphorylated extracellular signal-regulated kinases (p-ERKs), were up-regulated over 13-fold in H7 and H9 cultured on 70:30 FN:LN compared with gelatin. Blocking studies confirmed the role of all these molecules in CM specification, suggesting that the 70:30 FN:LN ECM promotes highly efficient differentiation of CMs through the integrin-mediated MEK/ERK signaling pathway. Lastly, the data suggest that FN:LN-induced signaling utilizes direct cell-to-cell signaling from distinct ITGB4(+) and ITGB5(+) cells.

No MeSH data available.


Related in: MedlinePlus