Deletion of COX-2 is associated with up-regulation of lymphocyte-related gene expression patterns, and down-regulation of rgl1 in tissue from fat-fed apoE^−/− mice.

Microarray analysis indicated 82, 87 and 90 differentially expressed genes (DEGs), respectively, in thymus (a), liver (b) and lung (c) from fat-fed apoE^−/−/COX-2^+/+ and apoE^−/−/COX-2^−/− mice. Volcano plot summaries of these data sets illustrate the distribution of effect size and statistical significance. Gene expression differing between genotypes >1.2-fold with p<0.05 highlighted in red, were considered for pathway analysis. Differential gene expression patterns demonstrated only weak overlap between tissues, but one gene, rgl1, was altered (down-regulated) in all tissues studied (d). Rgl1 down-regulation was confirmed in each tissue of apoE^−/−/COX-2^−/− mice by qPCR (e). Ingenuity pathway analysis of this data showed that in the thymus (f), liver (g) and lung (h), biological pathways/processes related to T- and/or B-lymphocyte function were amongst the most consistently altered pathways in each tissue. Tables show the top 15 altered biological pathways/processes and implicated genes (green: increased expression; red: decreased expression). Statistical testing of microarray data was performed using a linear model for microarray data modified t-test. n = 4.