Evidence for coregulation of myocardial gene expression by MEF2 and NFAT in human heart failure.
BACKGROUND
Pathological stresses induce heart failure in animal models through activation of multiple cardiac transcription factors (TFs) working cooperatively. However, interactions among TFs in human heart failure are less understood. Here, we use genomic data to examine the evidence that 5 candidate TF families coregulate gene expression in human heart failure.


RESULTS
RNA isolates from failing (n=86) and nonfailing (n=16) human hearts were hybridized with Affymetrix HU133A arrays. For each gene on the array, we determined conserved MEF2, NFAT, NKX , GATA , and FOX binding motifs within the -1-kb promoter region using human-murine sequence alignments and the TRANSFAC database. Across 9076 genes expressed in the heart, TF-binding motifs tended to cluster together in nonrandom patterns within promoters of specific genes (P values ranging from 10(-2) to 10(-21)), suggesting coregulation. We then modeled differential expression as a function of TF combinations present in promoter regions. Several combinations predicted increased odds of differential expression in the failing heart, with the highest odds ratios noted for genes containing both MEF2 and NFAT binding motifs together in the same promoter region (peak odds ratio, 3.47; P=0.005).


CONCLUSIONS
These findings provide genomic evidence for coregulation of myocardial gene expression by MEF2 and NFAT in human heart failure. In doing so, they extend the paradigm of combinatorial regulation of gene expression to the human heart and identify new target genes for mechanistic study. More broadly, we demonstrate how integrating diverse sources of genomic data yields novel insight into human cardiovascular disorders.
Putt
Mary E
ME
Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
Hannenhalli
Sridhar
S
Lu
Yun
Y
Haines
Philip
P
Chandrupatla
Hareesh R
HR
Morrisey
Edward E
EE
Margulies
Kenneth B
KB
Cappola
Thomas P
TP
D016208:Databases, Factual; D005786:Gene Expression Regulation; D006333:Heart Failure / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009206:Myocardium / Q000378:metabolism*; D018006:Myogenic Regulatory Factors / Q000235:genetics / Q000378:metabolism*; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016017:Odds Ratio; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic
D018006:Myogenic Regulatory Factors; D050778:NFATC Transcription Factors