Gene expression profiling of cultured cells from brainstem of spontaneously hypertensive and Wistar Kyoto rats

Hypertension is a multifactor disease that possibly involves alterations in gene expression in hypertensive relative to normotensive subjects that are largely unknown. In this study we used high-density oligoarrays to compare gene expression profiles in cultured neurons and glia from pons and medulla oblongata of newborn spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats, a widely documented animal model of hypertension. We found 358 genes differentially expressed between SHR and WKY brainstem cells that preferentially map to 24 metabolic/signaling pathways. Some of the pathways and regulated genes identified herein are obviously related to blood pressure regulation; however there are several genes differentially expressed in SHR not yet associated to hypertension or participating in blood pressure regulation. These constitute a rich resource for the identification and characterization of novel genes involved in hypertension development, or associated to phenotypical differences observed in SHR relative to WKI. In conclusion, this study describes for the first time the gene profiling pattern of brainstem cells from SHR and WKY rats, which opens up new possibilities and strategies of investigation and possible therapeutics to hypertension, as well as for the understanding of the brain contribution in this pathology. Keywords: Gene expression profiling of cultured cells from brainstem of spontaneously hypertensive and normotensive Wistar Kyoto rats Global measurements of gene expression from normotensive and hypertensive were obtained using the CodeLink Expression Bioarray System (GE Healthcare, UK), which interrogates 34,000 annotated genes and ESTs expressed in the rat genome. Each rat strain was hybridized in three independent biological replicates. Target labeling and hybridization was performed strictly as recommended by the array manufacturer. CodeLink Expression Analysis software (GE Healthcare) was used to extract background-subtracted spot intensities from microarray images. Measurements that were bellow the intensity of negative controls plus 2 standard deviations were excluded. Only genes with valid measurements in all three biological replicates of normotensive or hypertensive animals were further analyzed. To make experiments comparable, intensity data from different hybridizations were normalized by the quantile method