Uterine transcriptomes of bacteria-induced and ovariectomy-induced preterm labor in mice are characterized by differential expression of arachidonate metabolism genes

Objective The purpose of this study was to identify changes in gene expression that are associated with preterm labor induced by either bacteria or ovariectomy. Study design Pregnant mice (14.5 days of gestation) were allocated to: (1) intrauterine injection of heat-inactivated Escherichia coli; (2) media alone; (3) ovariectomy; or (4) sham operation. The uterine transcriptome was studied with photolithographic, very short oligonucleotide-based microarrays, and arachidonate metabolism genes were assayed with quantitative reverse transcriptase–polymerase chain reaction. Significance was determined by analysis of variance. Results Microarray-based gene expression changes in the arachidonate metabolism pathway are associated globally with bacteria-induced preterm labor (P ≤ .0031) and ovariectomy-induced preterm labor (P ≤ .00036). Quantitative real-time reverse transcriptase–polymerase chain reaction measurements demonstrated that bacteria-induced preterm labor substantially increased the expression of genes involved in prostaglandin synthesis. In contrast, ovariectomy-induced preterm labor increased the expression of genes involved in lipoxin, leukotriene, and hydroxyeicosatetraenoic acid synthesis. Conclusion Bacteria-induced and ovariectomy-induced preterm labor each express a different balance of genes that are required for the synthesis of prostaglandins, lipoxins, leukotrienes, and hydroxyeicosatetraenoic acids.