TY - JOUR
T1 - MEF2 transcriptional activity maintains mitochondrial adaptation in cardiac pressure overload
AU - el Azzouzi, Hamid
AU - van Oort, Ralph J.
AU - van der Nagel, Roel
AU - Sluiter, Wim
AU - Bergmann, Martin W.
AU - De Windt, Leon J.
PY - 2010/1
Y1 - 2010/1
N2 - The transcription factor MEF2 is a downstream target for several hypertrophic signalling pathways in the heart, suggesting that MEF2 may act as a valuable therapeutic target in the treatment of heart failure. In this study, we investigated the potential benefits of overall MEF2 inhibition in a mouse model of chronic pressure overloading, by subjecting transgenic mice expressing a dominant negative form of MEF2 (DN-MEF2 Tg) in the heart, to transverse aortic constriction (TAC). Histological analysis revealed no major differences in cardiac remodelling between DN-MEF2 Tg and control mice after TAC. Surprisingly, echocardiographic analysis revealed that DN-MEF2 Tg mice had a decrease in cardiac function compared with control animals. Analysis of the mitochondrial respiratory chain showed that DN-MEF2 Tg mice displayed lower expression of NADH dehydrogenase subunit 6 (ND6), part of mitochondrial Complex I. The reduced expression of ND6 in DN-MEF2 Tg mice after pressure overload correlated with an increase in cell death secondary to overproduction of reactive oxygen species (ROS). Our data suggest that MEF2 transcriptional activity is required for mitochondrial function and its inhibition predisposes the heart to impaired mitochondrial function, overproduction of ROS, enhanced cell death, and cardiac dysfunction, following pressure overload.
AB - The transcription factor MEF2 is a downstream target for several hypertrophic signalling pathways in the heart, suggesting that MEF2 may act as a valuable therapeutic target in the treatment of heart failure. In this study, we investigated the potential benefits of overall MEF2 inhibition in a mouse model of chronic pressure overloading, by subjecting transgenic mice expressing a dominant negative form of MEF2 (DN-MEF2 Tg) in the heart, to transverse aortic constriction (TAC). Histological analysis revealed no major differences in cardiac remodelling between DN-MEF2 Tg and control mice after TAC. Surprisingly, echocardiographic analysis revealed that DN-MEF2 Tg mice had a decrease in cardiac function compared with control animals. Analysis of the mitochondrial respiratory chain showed that DN-MEF2 Tg mice displayed lower expression of NADH dehydrogenase subunit 6 (ND6), part of mitochondrial Complex I. The reduced expression of ND6 in DN-MEF2 Tg mice after pressure overload correlated with an increase in cell death secondary to overproduction of reactive oxygen species (ROS). Our data suggest that MEF2 transcriptional activity is required for mitochondrial function and its inhibition predisposes the heart to impaired mitochondrial function, overproduction of ROS, enhanced cell death, and cardiac dysfunction, following pressure overload.
KW - MEF2
KW - NADH dehydrogenase subunit 6
KW - Transverse aortic constriction
KW - Mitochondria
KW - Heart failure
KW - Reactive oxygen species
U2 - 10.1093/eurjhf/hfp165
DO - 10.1093/eurjhf/hfp165
M3 - Article
C2 - 20023039
VL - 12
SP - 4
EP - 12
JO - European journal of heart failure
JF - European journal of heart failure
SN - 1388-9842
IS - 1
ER -