Expression and regulation of chemerin during rat pregnancy

BackgroundChemerin is an adipocytokine that is expressed in different fat deposits and has been shown to play an important role in adaptive and innate immunity due to its activity as a chemoattractant. Chemerin acts as a ligand for the G protein-coupled receptor chemokine - like receptor 1 (CMKLR1). Chemerin has been shown to regulate the development and metabolic function of adipocytes, liver and muscle tissue.ObjectiveThere is evidence indicating that several adipocytokines play an important role in placenta. This study aimed to investigate the regulation of chemerin in rat and human placentas throughout gestation.Design and settingChemerin was examined in rat and human placentas using immunohistochemistry. The chemerin expression pattern in the placenta and adipose tissue of female Sprague Dawley rats on days 12, 16, 19 and 21 of gestation (each of these days represents a group of 12 rats) was determined using TaqMan probe-based quantitative real-time PCR. Rat chemerin serum levels were analyzed with ELISA on days 8, 12, 16, 19 and 21 and compared to virgin controls.ResultsChemerin expression was detected in the cytoplasm of rat placental trophoblastic cells and third trimester human placental cytotrophoblast and Hofbauer’s cells. The serum chemerin levels of rats decreased significantly as gestation progressed. Furthermore, placental chemerin mRNA levels rose significantly at day 16 of gestation and decreased significantly towards the end of the gestation period.ConclusionTaken together, this data suggests that chemerin may be an important regulator of maternal-fetal metabolism and metabolic homeostasis during pregnancy.