Cluster analysis of genome-wide expression differences in disease-unaffected ileal mucosa in inflammatory bowel diseases
DOI: 10.1109/ICCABS.2011.5729884 Conference: IEEE 1st International Conference on Computational Advances in Bio and Medical Sciences, ICCABS 2011, Orlando, FL, USA, February 3-5, 2011
Whole human genome (Agilent) expression profiling was conducted on disease-unaffected ileal RNA collected from the proximal margin of resected ileum from 47 ileal Crohn's disease (CD), 27 ulcerative colitis (UC) and 25 control patients without inflammatory bowel diseases (IBD). Cluster analysis combined with significance analysis of microarrays (SAM) and principal component analysis (PCA) and was used to reduce the data dimension to identify geneprobe clusters associated with early pathogenic changes in ileal CD and UC. Ingenuity Pathway Analysis (IPA) was used to identify the biological pathways associated with each cluster. We reduced the dimensions of the 26,765 gene probe set to 43 gene-probe clusters. Most of these clusters could be labeled as related to different biological pathways, such as Paneth cell antimicrobial peptides, the formation of organized lymphoid structures, or nuclear receptor signaling and xenobiotic metabolism. Molecular phylogenetic 16S rRNA sequence analysis was completed on 83 DNA samples from the same samples used to generate the gene expression profiles. We conducted an exploratory study to determine if the first principle component (PC1) of these clusters could be linked to specific phyla/subphyla taxa.
Available from: Xiaofei Chen
[Show abstract] [Hide abstract]
ABSTRACT: In this work, we propose a novel genetic pathway discovery and comparison analysis framework integrating newly generated gene expression microarray data and existing biological pathway information. Starting with the significance analysis of microarray (SAM), a list of differentially expressed genes among groups is obtained. This gene list is then imported to the Ingenuity Pathway Analysis (IPA) to yield potentially relevant biological pathways. Finally, a newly-developed covariate structural equation modeling method is applied to evaluate gene-gene interactions and group difference. We illustrate this novel comparative pathway analysis pipeline using the whole human genome expression profiling data collected from a study of inflammatory bowel diseases (IBD) with 99 subjects from three phenotypic groups: ileal Crohn's disease (CD), ulcerative colitis (UC) and control non-IBD.
Available from: ncbi.nlm.nih.gov
[Show abstract] [Hide abstract]
ABSTRACT: Culture-independent microbiological technologies that interrogate complex microbial populations without prior axenic culture, coupled with high-throughput DNA sequencing, have revolutionized the scale, speed and economics of microbial ecological studies. Their application to the medical realm has led to a highly productive merger of clinical, experimental and environmental microbiology. The functional roles played by members of the human microbiota are being actively explored through experimental manipulation of animal model systems and studies of human populations. In concert, these studies have appreciably expanded our understanding of the composition and dynamics of human-associated microbial communities (microbiota). Of note, several human diseases have been linked to alterations in the composition of resident microbial communities, so-called dysbiosis. However, how changes in microbial communities contribute to disease etiology remains poorly defined. Correlation of microbial composition represents integration of only two datasets (phenotype and microbial composition). This article explores strategies for merging the human microbiome data with multiple additional datasets (e.g. host single nucleotide polymorphisms and host gene expression) and for integrating patient-based data with results from experimental animal models to gain deeper understanding of how host-microbe interactions impact disease.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.