TY - JOUR
T1 - Conditional expression of SV40 T-antigen in mouse cardiomyocytes facilitates an inducible switch from proliferation to differentiation
AU - Rybkin, Igor I.
AU - Markham, David W.
AU - Yan, Zhen
AU - Bassel-Duby, Rhonda
AU - Williams, R. Sanders
AU - Olson, Eric N.
PY - 2003/5/2
Y1 - 2003/5/2
N2 - Studies of cardiac muscle gene expression and signaling have been hampered by the lack of immortalized cardiomyocyte cell lines capable of proliferation and irreversible withdrawal from the cell cycle. With the goal of creating such cell lines, we generated transgenic mice using cardiac-specific cis-regulatory elements from the mouse Nkx2.5 gene to drive the expression of a simian virus 40 large T-antigen (TAg) gene flanked by sites for recombination by Cre recombinase. These transgenic mice developed tumors within the ventricular myocardium. Cells isolated from these tumors expressed cardiac markers and proliferated rapidly during serial passage in culture, without apparent senescence. However, they were unable to exit the cell cycle and failed to exhibit morphological features of terminal differentiation. Introduction of Cre recombinase to these cardiac cell lines by adenoviral delivery resulted in the elimination of TAg expression, accompanied by rapid cessation of cell division, and increase in cell size without an apparent induction of cellular differentiation. Incubation of cells lacking TAg in serumdeficient media with various pharmacological agents (norepinephrine, phenylephrine, or bone morphogenetic protein-2/4) or constitutively active calcium/calmodulin-dependent protein kinase I and/or calcineurin led to the formation of sarcomeres and up-regulation of cardiac genes involved in excitation-contraction coupling. The combination of TAg expression under the control of an early cardiac promoter and Cre-mediated recombination allowed us to derive an immortal cell line from the ventricular myocardium that could be controllably withdrawn from the cell cycle. The conditional expression of TAg in this manner permits propagation and regulated growth termination of cell types that are otherwise unable to be maintained in cell culture and may have applications for cardiac repair technologies.
AB - Studies of cardiac muscle gene expression and signaling have been hampered by the lack of immortalized cardiomyocyte cell lines capable of proliferation and irreversible withdrawal from the cell cycle. With the goal of creating such cell lines, we generated transgenic mice using cardiac-specific cis-regulatory elements from the mouse Nkx2.5 gene to drive the expression of a simian virus 40 large T-antigen (TAg) gene flanked by sites for recombination by Cre recombinase. These transgenic mice developed tumors within the ventricular myocardium. Cells isolated from these tumors expressed cardiac markers and proliferated rapidly during serial passage in culture, without apparent senescence. However, they were unable to exit the cell cycle and failed to exhibit morphological features of terminal differentiation. Introduction of Cre recombinase to these cardiac cell lines by adenoviral delivery resulted in the elimination of TAg expression, accompanied by rapid cessation of cell division, and increase in cell size without an apparent induction of cellular differentiation. Incubation of cells lacking TAg in serumdeficient media with various pharmacological agents (norepinephrine, phenylephrine, or bone morphogenetic protein-2/4) or constitutively active calcium/calmodulin-dependent protein kinase I and/or calcineurin led to the formation of sarcomeres and up-regulation of cardiac genes involved in excitation-contraction coupling. The combination of TAg expression under the control of an early cardiac promoter and Cre-mediated recombination allowed us to derive an immortal cell line from the ventricular myocardium that could be controllably withdrawn from the cell cycle. The conditional expression of TAg in this manner permits propagation and regulated growth termination of cell types that are otherwise unable to be maintained in cell culture and may have applications for cardiac repair technologies.
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U2 - 10.1074/jbc.M213102200
DO - 10.1074/jbc.M213102200
M3 - Article
C2 - 12590133
AN - SCOPUS:0037507281
SN - 0021-9258
VL - 278
SP - 15927
EP - 15934
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 18
ER -