Changes in syncytiotrophoblast (hST) membrane lipid composition after insulin treatment

CASTRO-PARODI, MAURICIO; WEBER, KAREN; RECA, ALEJANDRA; CASALI, CECILIA IRENE; . FERNÁNDEZ TOME, MARIA DEL CARMEN; DAMIANO, ALICIA E.

Ciudad Autónoma de Buenos Aires

Jornada; XI I Jornadas anuales de la Sociedad Argentina de Biología; 2010

Sociedad Argentina de Biología

It was previously demonstrated that preeclamptic hST is more rigid than normal hST. Since we observed high serum levels of insulin in preeclamptic women, we hypothesized that insulin may be implicated in the change observed in preclamptic hST. The aim of this study was to evaluate if insulin may alter the lipid composition of hST. Explants from normal term placentas were cultured with different concentrations of insulin during 24 h. Apical (MVM) and basal (BM) membrane vesicles were prepared by differential centrifugation. Lipids were extracted by Bligh-Dyer method, phospholipids (phLs) separated by TLC and quentified by Fiske-Subarrow. Cholesterol was determined by enzymatic method. Insulin treatment produced no changes in the total lipid content until reaching a constant value of 100 μUI/mL of insulin. Such an increase in MVM was correlated with sphingomyelin and phosphatidylcholine content increase and no changes were found in other PhL species and Chol. Our results suggest that insulin may alter lipid composition and in addition membrane fluidity. Further work is needed to clarify the molecular mechanisms implicated in these changes and its role in the pathogenesis of preeclampsia.