Project description:The cardiovascular restricted transcription factor CHF1/Hey2 has been previously shown to regulate the smooth muscle response to growth factors. To determine how CHF1/Hey2 affects the smooth muscle response to growth factors, we performed a genomic screen for transcripts that are differentially expressed in wild type and knockout smooth muscle cells after stimulation with platelet derived growth factor. We screened 45101 probes representing more than 39,000 transcripts derived from at least 34,000 genes, at eight different time points. We analyzed the expression data utilizing an algorithm based on Bayesian statistics to derive the best polynomial clustering model to fit the expression data. We found that in a total of 9827 transcripts the normalized ratio of knockout to wild type expression diverged more than 3 fold from baseline in at least one time point, and these transcripts separated into 17 distinct clusters. Further analysis of each cluster revealed distinct alterations in gene expression patterns for immediate early genes, transcription factors, matrix metalloproteinases, signaling molecules and other molecules important in vascular biology. Experiment Overall Design: WT and Hey2 knockout mouse aortic smooth muscle cells were treated in parallel with PDGF and harvested at successive time points for RNA extraction and hybridization on Affymetrix microarrays. We sought to identify differentially expressed transcripts through Bayesian statistical methods that would explain the differential response to PDGF observed in vitro.
Project description:To elucidate the role of SIRT1 in adult neural stem cells, we have carried out a genome-wide microarray analysis on cultured adult neurospheres from wildtype (WT) and sirt1 knockout (KO) mice and WT neurospheres treated with DMSO and SIRT1 activator,resveratrol for 24 hours. Then we screened for genes that exhibited opposite changing patterns beween KO-versus-WT and resveratrol-versus-DMSO-treated groups. Our result revealed a significant enrichment of genes involved in metabolic process. And numerous genes involved in cell proliferation and differentiation were represented in these SIRT1-responsive genes. More interestingly, Notch signaling-related genes,such as Dll4, Mib1,Hes5, Heyl, Hey2 and so on, also showed a significant enrichment. Real-time PCR validated the expression of Notch signaling-related genes. These data revealed the regulation of SIRT1 on the self-renewal and differentiation of adult neural stem cells.
Project description:Transcriptional profiling time course of serum deprived quiescent human T98G cells follwing platelet derived growth factor (PDGF) stimulation in the absence and presence of the translation inhibitor, cycloheximide. RNA was harvested at 0.5, 2, and 4 hr following PDGF treatment. Keywords: time course
