Expression of genes involved in inflammation and growth - does sampling site in human full-term placenta matter?

Objective: To investigate the placental gene expression of substances in the inflammatory cascade and growth factors at nine different well-defined sampling sites in full-term placentas from 12 normal weight healthy non-smoking women with an uncomplicated singleton pregnancy. Methods: All placentas (six girls and six boys) were delivered vaginally. Quantitative real-time polymerase chain reaction was used to analyze toll receptor-2 and -4, interleukin-6 and -8, tumor necrosis factor-alpha, leptin, ghrelin, insulin-like growth factor-1 and -2, hepatocyte growth factor, hepatocyte growth factor receptor and insulin receptor (IR). Results: The leptin gene and the IR gene showed higher expression in lateral regions near the chorionic plate compared to central regions near the basal plate (P = 0.028 and P=0.041, respectively). Conclusion: Our results suggest that the sampling site may influence the gene expression for leptin and IR in placental tissue obtained from full-term normal pregnancies. We speculate that this may be due to differences in placental structure and perfusion and may be important when future studies are designed.