NFATc2 is a necessary mediator of calcineurin-dependent cardiac hypertrophy and heart failure.
One major intracellular signaling pathway involved in heart failure employs the phosphatase calcineurin and its downstream transcriptional effector nuclear factor of activated T-cells (NFAT). In vivo evidence for the involvement of NFAT factors in heart failure development is still ill defined. Here we reveal that nfatc2 transcripts outnumber those from other nfat genes in the unstimulated heart by severalfold. Transgenic mice with activated calcineurin in the postnatal myocardium crossbred with nfatc2-null mice revealed a significant abrogation of calcineurin-provoked cardiac growth, indicating that NFATc2 plays an important role downstream of calcineurin and validates the original hypothesis that calcineurin mediates myocyte hypertrophy through activation of NFAT transcription factors. In the absence of NFATc2, a clear protection against the geometrical, functional, and molecular deterioration of the myocardium following biomechanical stress was also evident. In contrast, physiological cardiac enlargement in response to voluntary exercise training was not affected in nfatc2-null mice. Combined, these results reveal a major role for the NFATc2 transcription factor in pathological cardiac remodeling and heart failure.
Bourajjaj
Meriem
M
Hubrecht Institute and Interuniversity Cardiology Institute Netherlands, Royal Netherlands Academy of Sciences, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
Armand
Anne-Sophie
AS
da Costa Martins
Paula A
PA
Weijts
Bart
B
van der Nagel
Roel
R
Heeneman
Sylvia
S
Wehrens
Xander H
XH
De Windt
Leon J
LJ
D000818:Animals; D019703:Calcineurin / Q000378:metabolism*; D006332:Cardiomegaly / Q000503:physiopathology*; D006333:Heart Failure / Q000503:physiopathology*; D051379:Mice; D008822:Mice, Transgenic; D009206:Myocardium / Q000737:chemistry; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms
D050778:NFATC Transcription Factors; C494007:Nfatc2 protein, mouse; D020033:Protein Isoforms; D019703:Calcineurin