The major endocannabinoid (eCB) 2-arachidonoylglycerol (2-AG) is a member of the Endocannabinoid System (ECS) that participates in cell proliferation and apoptosis, important events for the homeostasis of biological systems. Placenta formation is one of the most important stages of pregnancy and its development requires a highly regulated proliferation, differentiation and apoptosis of trophoblasts. Anomalies in these processes are associated with gestational pathologies. Here, we intended to study the involvement of 2-AG in cytotrophoblast cell turnover. We found that 2-AG biosynthetic (Diacylglycerol lipase A- DAGLA) and degradation (Monoacylglycerol lipase-MAGL) enzymes are expressed in human cytotrophoblasts and in BeWo cells. Also, 2-AG induces a decrease in cell viability, in a time and concentration-dependent manner and exerts antiproliferative effects. The cell viability loss induced by a 48h-treatment with 2-AG (10 μM) was accompanied by chromatin fragmentation and condensation, morphological features of apoptosis. Additionally, 2-AG induced an increase in caspase 3/7 and 9 activities, loss in mitochondrial membrane potential (ψm) and reactive oxygen/nitrogen species (ROS/RNS) generation, suggesting the activation of the mitochondrial pathway. Moreover, whereas the loss of ψm and ROS/RNS generation were significantly attenuated by both Cannabinoid Receptors 1 and 2 (CB1, CB2) antagonists, the increase in caspase 3/7 and 9 activities and cell viability loss were only reversed by CB2 antagonist; the blockage of the eCB membrane transporter and the cholesterol depletion failed the reversion of 2-AG effects. Therefore, this study supports the importance of cannabinoid signalling during cytotrophoblast cell turnover and that its deregulation may be implicated in altered placental development and poor pregnancy outcome.

PMID:

 24324206
[PubMed – as supplied by publisher]