Transcriptome Profiling Reveals PHLDA1 as a Novel Molecular Marker for Ischemic Cardiomyopathy

Ischemic cardiomyopathy (ICM) represents a worldwide health issue owning to its high sudden death rate. Easy diagnosis and effective treatment of ICM are still lacking. Identification of novel molecular markers will help illustrate the pathophysiology of ICM and facilitate its diagnosis and targeted treatment. Transcription profiling could be an easy and efficient way for identifying new markers. However, the mega data in the available database may contain a large number of false-positive hits. To identify the true marker for ICM, we systematically compared available microarray datasets in the GEO database and identified 26 genes that are shared by all datasets. We further verified the expression pattern of these 26 genes in ICM rat model. Only 12 genes show significant differential expression in our animal model. Among them, we focused on PHLDA1, a well-documented pro-apoptotic factor. Expression of PHLDA1 was elevated in both ischemic cardiac cell lines and in rat model. Overexpression of PHLDA1 promotes apoptosis of cardiac muscle cell. Meanwhile, PHLDA1 not only inhibited AKT pathway, but also activated p53 pathway. We thus confirmed PHLDA1 as a true molecular marker for ICM.