MIF is among the proinflammatory cytokines increased by LPS in the human trophoblast line

Abstract

Infection is increasingly considered to contribute to pathological conditions in pregnancy. The placenta acts as a protective immunological fetomaternal barrier which recognizes microbes by pattern recognition receptors on the trophoblast. Lipopolysaccharide (LPS) is a cell wall constituent of Gram-negative bacteria that elicits a strong immune response. In this study, LPS from E. coli was used to treat the HTR-8/SVneo trophoblast cell line and examine its influence on cytokines IL-6, IL-8 and MIF using real-time PCR, metalloproteinases (MMP)-2 and -9 by gelatin zymography, and Western analysis of integrin subunits α1 and β1, all known to contribute to migration of human trophoblasts in vitro. The results described herein for the first time, show that MIF mRNA and secreted MIF protein were significantly elevated (2.5-3- and 2-fold, respectively) in LPS-treated cells. MMP-2 and MMP-9 levels were increased, as well as cell migration, as judged by a wound-healing test, however, no changes in the studied integrin subunits, cell viability or cell numbers were observed. The data obtained furthers our understanding of LPS actions on the trophoblast in vitro, additionally implicate MIF, and suggest that infection in vivo could indeed alter the functional characteristics of the trophoblast.