Objective-Preterm delivery is often associated with increased cytokine and chemokine production. These studies sought to characterize the expression of the chemokine, monocyte chemotactic protein-1 (MCP-1), in mice during lipopolysaccharide (LPS)-induced preterm delivery.Methods-Uterine and other tissues were harvested from CD-1 mice on gestational day 15 after intrauterine LPS injection. Quantitative real-time reverse-transcriptase polymerase chain reactions (qRT-PCR) determined MCP-1 and toll-like receptor 4 (TLR4) mRNA expression during the 24 hours after LPS. MCP-1 protein expression was determined using a cytokine/chemokine protein array, by ELISA and by immunohistochemistry.Results-Intrauterine LPS injection caused preterm delivery in CD-1 mice between 12 and 24 hours. Expression of MCP-1 mRNA significantly increased at 2 and 6 hours, while TLR4 expression did not significantly change over 24 hours. MCP-1 protein levels peaked by 2 to 6 hours in maternal serum, liver, lung, kidney and uterus. Immunohistochemistry confirmed MCP-1 in myometrium and endometrium.Discussion-These studies have provided evidence suggesting that MCP-1 potentially plays an important role during the proinflammatory immune response leading to preterm labor in the mouse.

Preterm delivery (PTD) has been associated with inflammation along with activation of the coagulation pathway. These studies sought to characterize the expression of several coagulation pathway genes including plasminogen activator inhibitor 1 (PAI-1), tissue factor (TF), protease-activated receptor 1 (Par1), protease-activated receptor 2 (Par2), fibrinogen-like protein 2 (Fgl2), and thrombomodulin (TM) during lipopolysaccharide (LPS)-induced PTD in day 15 pregnant CD-1 mice. Western blot studies confirmed protein expression for PAI-1, Par1, Par2, Fgl2, and TM in the mouse uterus. Quantitative reverse transcriptase polymerase chain reaction (RT-PCR) confirmed increased PAI-1 messenger RNA (mRNA) in the uteri, lung, kidney, and liver tissues at 2 to 6 hours after LPS injection. In contrast, TF expression significantly decreased by 12 hours in uterine tissue; whereas, its expression was unchanged in the other maternal tissues. The uterine mRNA for Par1, Par2, Fgl2, and TM remained stable. In summary, these studies have confirmed expression of coagulation pathway genes within the pregnant uterus; some of which are modulated during LPS-induced PTD.