Adipokines, an adipose tissue and placental product with biological functions during pregnancy

Abstract

Latter half of pregnancy is characterized by a "physiological diabetogenic state" since changes in insulin-sensitivity have been well documented. These changes ensure continuous supply of nutrients to the growing fetus. In the last years the role of adipocyte-derived signaling molecules, collectively known as adipokines has been object of different in vitro and in vivo studies. Of interest, adipokines and/or their receptors are expressed in the placental tissue which, therefore, can contribute to development of maternal insulin-resistance and, as a consequence, fetal growth. Leptin, adiponectin, and resistin represent the most well studied adipokines and, with the exception of adiponectin, their serum and placental levels increase as pregnancy progresses. High levels of adipokines have also been detected in umbilical plasma hence suggesting a possible role on fetal development and metabolism; however, it remains still unclear if such adipokines can directly stimulate fetal tissues development acting as growth factors. In addition to their well known metabolic effects, we also reported studies describing the role of adipokines in promoting proliferation and invasiveness of trophoblast cells and affecting local angiogenic processes. These observations strongly suggest that adipokines, by alternatively interfering with placental development, may affect pregnancy outcome and fetal growth. However, further studies are needed to better understand the local regulation of their expression. © 2012 International Union of Biochemistry and Molecular Biology, Inc.

Relationship of circulating adipokines to body composition in pregnant women

“…34 It is hypothesized that maternal circulation of leptin is important for mobilization of fat deposits to ensure energy availability for the fetus. 35 Because measurement of plasma leptin in this study occurred within a narrow gestational timeframe (35-39 weeks), we do not believe differences in placental leptin production were responsible for the differences in leptin concentration seen between normal weight and overweight/obese pregnant women.…”

Increased risk for the development of preeclampsia in obese pregnancies: weighing in on the mechanisms

“…Human studies suggest that preeclamptic patients express exaggerated metabolic profiles, including hyperleptinemia, hyperinsulinemia, insulin resistance, and hyperlipidemia, which precedes the appearance of the clinical symptoms (25,38,100,169). Intriguingly, in vitro and in vivo studies have shown that depending on the concentration of obesity-related metabolic factors, there are beneficial or detrimental effects on placentalfetal development and vascular function (33,62). We and others (146) believe that obese pregnant women having an extremely abnormal metabolic profile are at increased risk to develop PE.…”

La chémérine

“…Chez la femme, les concentrations sériques de plusieurs adipocytokines, comme la leptine [46,47], la visfatine [46], la résistine [46,47], ainsi que celle du TNF- [47], sont plus élevées en fin de grossesse, alors que les taux d'adiponectine circulante [46,47] sont diminués. De la même manière, la concentration de chémérine augmente au cours de la grossesse chez la femme, contrairement à ce hyperinsulinémie prolongée provoque une augmentation de la concentration de chémérine chez des individus sains [36].…”