Monocyte chemotactic protein-1 expression is increased in human gestational tissues during term and preterm labor

Objective: Microarray analysis was used to characterize the labor-selective transcriptome of the human myometrium during labor. One highly up-regulated transcript, monocyte chemotactic protein-1 (MCP-1), was further characterized. Methods: Expression of MCP-1 was evaluated in the myometrium, the placenta, the gestational membranes (GM) and the amniotic fluid (AF) by real time RT-PCR, Northern blot analysis and ELISA. The level of immunoreactive (IR) MCP-1 content of primary myometrial cultures treated with inflammatory cytokines was quantified by ELISA. Results: Up-regulation of the myometrial MCP-1 transcript in term laboring patients was demonstrated by microarray and confirmed by real time (RT)-PCR and Northern blot analysis. Increased MCP-1 transcripts were demonstrated in GM during term labor. The IR content of myometrial MCP-1 was increased during term labor and in the AF from patients experiencing preterm delivery. Levels of IR MCP-1 increased in myometrial cultures in response to interleukin 1-beta. Conclusion: The expression of myometrial MCP-1 was significantly increased during term labor and was similarly increased in vitro in response to interleukin 1-beta, a pro-inflammatory substance known to play a role in preterm birth. The increased IR content of MCP-1 within the AF preceding preterm delivery may render this protein a useful predictor of preterm birth.