Identification of genes regulated by Interleukin - 1β in human endometrial stromal cells

Interleukin-1 beta (IL-1 beta) is an important immune regulatory factor that in human endometrium plays a role in both menstruation and implantation in the event of pregnancy. It promotes inflammatory-like processes and also stimulates tissue remodelling. We present a cDNA microarray study documenting the major effects of IL-1 beta on gene expression in stromal cells from human endometrium. Endometrial stromal cells from five normal healthy women at the mid secretory phase were cultured with or without IL-1 beta at 50 and 500 pg/ml for 48 h. cDNA microarrays were used to compare the levels of gene expression in total RNA isolated from cells stimulated with IL-1 beta. These cDNA arrays were produced containing 15 164 sequence-verified clones, which included genes known to be important in angiogenesis, immune modulators, apoptosis, cell signalling, extracellular matrix (ECM) remodelling and cell cycle regulation. Genes which were regulated by IL-1 beta were identified by analysis of the microarray data using the Significance Analysis of Microarrays software package. Upregulated (n = 23) and downregulated (n = 6) different genes were observed, which changed at least 3-fold, at a false discovery rate of less than 2% (P < 0.02). Our results have identified genes regulated by IL-1 beta, which are involved in leukocyte recruitment, ECM remodelling and other cellular functions. Changes in three genes, IL-8, colony-stimulating factor 2 and aldo-keto reductase family 1 member 1, which were upregulated by IL-1 beta, were verified using real-time PCR. Novel functions regulated by IL-1 beta in endometrium, including genes involved in free radical protection, and fatty acid metabolism were also identified. These results also provide new insights into the role of IL-1 beta in disorders of the endometrium, especially in implantation-related infertility and endometriosis, in which this cytokine plays a major role.