Effects of leptin on lipopolysaccharide-induced myometrial apoptosis in an in vitro human model of chorioamnionitis

OBJECTIVE: This study was aimed at assessing the role of leptin on human myometrium, by studying its receptor expression in pregnant myometrium and the interaction of leptin with inflammation-induced apoptosis. STUDY DESIGN: Myometrial samples were obtained from women with uncomplicated pregnancies who underwent cesarean delivery at term before labor onset. The effect of leptin on apoptosis was assessed by the incubation of myometrial strips with leptin (10^-10 to 10^-8 mol/L; 48 hours) before lipopolysaccharide treatment (10μg/mL; 48 hours). RESULTS: Long and short leptin receptor isoforms were expressed in myometrial cells of pregnant women. Leptin prevented lipopolysaccharide-induced apoptosis, in a concentration-dependent manner, by down-regulating cleaved caspase-3 and BCL2-associated X protein and up-regulating BCL2 expression. This effect was mediated specifically through leptin receptor stimulation, followed by ERK1/2 signaling pathway activation. CONCLUSION: These results suggest a new potential pathway that is involved in delivery disorders of obese women and propose a role for the leptin-induced inhibition of myometrial apoptosis in the development of such disorders.