Update tissue-networks.rst

docs/tissue-networks.rst

@@ -27,3 +27,16 @@ To estimate shared transcription factor regulation between genes, we collected b
 
 MSigDB purturbations and miRNA:
 Chemical and genetic perturbation (c2:CGP) and microRNA target (c3:MIR) profiles were downloaded from the Molecular Signatures Database (MSigDB). Each gene pair's score was the sum of shared profiles weighted by the specificity of each profile
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+Examples
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+IL1B in blood vessel
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+We examined and experimentally verified the tissue-specific molecular response of blood vessel cells to stimulation by IL-1β (IL1B), a proinflammatory cytokine. We anticipated that the genes most tightly connected to IL1B in the blood vessel network would be among those responding to IL-1β stimulation in blood vessel cells. We tested this hypothesis by profiling the gene expression of human aortic smooth muscle cells (HASMCs; the predominant cell type in blood vessels) stimulated with IL-1β. 
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+Examination of the genes whose expression was significantly upregulated at 2 h after stimulation showed that 18 of the 20 IL1B network neighbors were among the top 500 most upregulated genes in the experiment (P = 2.07 × 10−23). The blood vessel network was the most accurate tissue network in predicting this experimental outcome; none of the other 143 tissue-specific networks or the tissue-naive network performed as well when evaluated by each network's ability to predict the result of IL-1β stimulation on the cells. 
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+.. figure:: http://www.nature.com/ng/journal/v47/n6/images/ng.3259-F2.jpg
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+We anticipated that the genes most tightly connected to IL1B in the blood vessel network would be among those responding to IL-1β stimulation in blood vessel cells (a) The 20 genes most tightly connected to IL1B in the blood vessel network are shown. These genes are predicted to respond to IL-1β stimulation in blood vessel. (b) The bar plot shows the differential expression levels of the 20 IL1B neighbors measured in a microarray experiment at 0 h and 2 h after IL-1β stimulation in HASMCs, which constitute most of the blood vessel. Each bar represents the gene's log ratio of mean expression at 2 h over its mean expression at 0 h. Error bars represent regularized pooled standard errors estimated by LIMMA (n = 4 biological replicates). Eighteen of the 20 IL1B network neighbors (labeled in bold) were found to be among the most significantly differentially expressed genes at 2 h relative to 0 h (P = 1.95 × 10−23).