Role of lipid rafts in human placental nitric oxide production

CINTYA ABAN; SABINA M. MATÉ.; FARINA MARIANA; GUSTAVO LEGUIZAMON; VANESA HERLAX; DAMIANO ALICIA; MARTÍNEZ NORA; ANA FRANCHI

Las Vegas

Congreso; 37 th Annual Pregnancy Meeting de la Society for Maternal-Fetal Medicine; 2017

OBJECTIVE: Abnormal Nitric Oxide (NO) production has beenassociated with pregnancy complications. Anandamide (AEA) is anendocannabinoid produced by the placenta that acts as endogenousligand of cannabinoid (CBs) and vinilloid (TRPV 1) receptors.AEA can modulate NO production. We aim to determine the roleof lipid rafts (LRs) on the differential regulation of AEA on NOproduction.STUDY DESIGN: Placental samples from term labor (TL) (n¼14) andterm no labor (TNL) (n¼15) women were obtained. Placental explantswere incubated with AEA (10 -7 M), capsazepin, antagonist ofTRPV1 (CZP) (10 -6 M), capsaicin, agonist of TRPV1 (CSI) (10 -6);and AM251, antagonist of CB1 receptor (10 -7). Subsequently, nitricoxide synthase (NOS) activity was determined by Bredt & Snydertechnique. Two main components of LRs, Flotillin-1 and caveolin-1(cav-1), were analyzed in detergent resistant membranes obtainedby ultracentrifugation. The expression of CB1, TRPV1, eNOS,caveolin-1, and flotillin-1 was determined by Western Blot analysis.Localization of TRPV1 and CB1 receptors was analyzed byimmunohistochemistry.RESULTS: Activity of NOS was not different between labor and nolabor explants. AEA presented a dual effect increasing NOS activityin (TNL) and decreasing in (TL) explants (p<0,001). This effect wasreverted with CB1 receptor antagonist (AM 251) co-incubation, butnot with TRPV1 antagonist (CZP). CB1 translocate basal membranein TL explants, while eNOS is detected in apical membrane, and colocalizingwith cav-1.CONCLUSION: Anandamide presents a dual effect. While enhancesNOS activity through CB1 in term non-laboring placentas, it decreasesNO production through LRs in placentas from term laboringpatients.