PARTICIPATION OF ENDOCANNABINOIDS IN PLACENTAL APOPTOSIS

ABAN C; MARTÍNEZ N,; CAROU C; TRIGUBO D; LEGUIZAMÓN G; FRANCHI A; DAMIANO A; FARINA M

Simposio; VI LatinAmerican Symposium on Maternal-Fetal Interaction & Placenta; 2015

Apoptosis is an important process that plays a major role in the physiologica development of human placenta. It has been observed that an aberrant cell turnover including an increased apoptosis is implicated in the pathogenesis of many disorders of pregnancy.Hypoxia inducible Factors (HIFs) act as key regulators of trophoblast invasión and differentiation through regulation of the expression of different genes. The catalytic HIF1a subunit is expressed in human placentas and can also induce genes involved in cell death.Endocannabinoids (ECs) are bioactive lipids implicated in placental physiology that exert their effect by the activation of cannabinoid receptors CB1 and CB2. ECs, together with their receptors are part of the Endocannabinoid System (ES) and could induce apoptosis in different cell types including cytotrophoblast cells. Previously, we demonstrated that the ES is present in human term placenta.Objective: To investigate the participation of ECs in human placental apoptosis generated by HIF1a.Methods: Explants obtained from normal placentas (n¼8) were cultured with Cobalt chloride (CoCl2, a hypoxia-mimetic agent), Met-AEA (a stable EC agonist) and/or AM251 (a CB1 antagonist). Explant viability was evaluated by MTT assay. Cleaved caspase-3, Bax and Bcl-2 protein expression and caspase-3 activity were determined as apoptotic parameters.Results: CoCl2 treatment induced a decrease in the viability of the placental tissue. Instead, co-incubation with AM251 blocked this effect.Incubation with CoCl2 or Met-AEA increased cleaved caspase 3 (active form) expression. Additionally, we detected an increase in the Bax/Bcl-2 ratio and caspase 3 activity. The expression and enzymatic activity of these proteins diminished after co-incubation with AM251 (p<0.05).Conclusions: Our results suggest that ECs may be involved in the apoptotic events induced by HIF, via a mechanism mediated by CB1 receptor in the human placenta. Further studies are needed to determine their role in pathological conditions.