PARENT SESSION
Pregnancy and Parturition
588
EXPRESSION OF SUPPRESSOR OF CYTOKINE SIGNALING (SOCS)-1, SOCS-2, AND SOCS-3 IN HUMAN PLACENTA AND GESTATIONAL MEMBRANES: EFFECTS OF LABOR AND INTRAUTERINE INFECTION.
Bowen, Jennifer1,2, Blumenstein, Marion1,2, Marvin, Keith1,2, Keelan, Jeffrey1,2, Mitchell, Murray1,2, 1 2
ABSTRACT- Cytokines are critical paracrine and autocrine regulators in human pregnancy and parturition. Inflammatory cytokines secreted by the placenta and fetal membranes in association with the onset of labor or in response to bacterial infection are believed to play an important role in the initiation of uterine contractions, membrane rupture and delivery. Some anti-inflammatory cytokines, such as interleukin-10, may also alter their behavior under these conditions to increase and sustain inflammatory changes. The suppressor of cytokine signaling (SOCS) proteins negatively regulate signal transduction by a number of cytokines, including inflammatory and anti-inflammatory cytokines that affect gestational tissues. The presence of SOCS-1 and its role as a negative regulator of prolactin signaling have been reported in the decidua of rats. However, the distribution and roles of SOCS proteins have not been described for human gestational tissues. Using reverse transcription-polymerase chain reaction, we investigated whether the genes for SOCS-1, SOCS-2 and SOCS-3 were expressed in human villous placenta, amnion and choriodecidua obtained from deliveries at term and preterm. Samples were obtained from term deliveries with (n=4) and without (n=4) exposure to labor and from preterm, labored deliveries with (n=4) and without (n=4) intrauterine infection. Messenger RNAs for the three SOCS proteins were expressed in all tissues under conditions in which inflammatory cytokines are elevated in the uterine environment (labor, infection) and also under conditions in which these cytokines are comparatively low (no labor, no infection). Production of SOCS proteins in human gestational tissues under these conditions is being investigated using Western blot analysis. Initial studies have examined SOCS-2 protein in the presence or absence of labor at term. Our results indicate that SOCS-2 protein is present in the villous placenta following exposure to labor but is not detectable in placenta obtained from caesarian section deliveries (no labor) or in amnion or choriodecidua from either condition. In contrast, preliminary results suggest that SOCS-1 and SOCS-3 are present in the fetal membranes at term. These results may provide an explanation for differential actions of cytokines in gestational tissues.
KEY WORDS: pregnancy, parturition, cytokine, suppressor of cytokine signaling