Human epidemiological studies have shown a clear association of adverse intrauterine environment and an ncreased risk of ischemic heart disease in later adult life. Cocaine abuse among women of childbearing age s prevalent in the United States, and is associated with numerous adverse perinatal outcomes including cardiac dysfunctions. Recently, we have found that prenatal cocaine exposure causes an increase in heart susceptibility to ischemia and reperfusion injury in adult offspring, which may be gender-dependent. Among other mechanisms, numerous studies have demonstrated that PKCe plays a pivotal role of cardioprotection during cardiac ischemia and reperfusion injury. Our preliminary data showed that prenatal cocaine exposure decreased PKCe protein levels selectively in the heart of male, but not female, adult offspring, suggesting an n utero, gender-specific epigenetic programming of PKCe gene expression pattern in the heart. The Droposed studies focus on the underlying mechanisms, and will test the main hypothesis that prenatal cocaine exposure causes a gender-specific increase in DMAmethylation of the PKCe gene and a down- regulation of PKCe gene expression in the heart, resulting in an increased heart susceptibility to ischemia and reperfusion injury in adult male offspring. Four of its main corollaries will be addressed by 4 Specific Aims, which will test whether prenatal cocaine exposure causes 1) a gender-specific increase in heart susceptibility to ischemia and reperfusion injury in adult offspring, 2) a gender-specific down-regulation of PKCe gene expression in the heart, 3) a gender-specific increase in DMA methylation of the PKCe gene in the heart, and 4) whether DMAmethylation of the PKCe gene plays a key role in the prenatal cocaine- induced, gender-specific increase in heart susceptibility to ischemia and reperfusion injury. To achieve these aims, we propose a series of experiments in a pregnant rat model, and will determine the effects of prenatal cocaine exposure on DMA methylation of the PKCe gene, PKCe gene expression, and postischemic recovery of left ventricular function and myocardial infarct size in hearts of male and female fetuses, and male and female juvenile and adult offspring. The results will provide exciting novel insights into molecular mechanisms of epigenetic programming in the gene expression pattern involved in the adverse effects of cocaine on the heart development, and its lifelong pathophysiologic consequences in the adult heart.
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