DOCOSAHEXAENOIC ACID SUPPLEMENTATION DURING PREGNANCY MODULATES THE GENE EXPRESSION OF SOME FATTY ACID TRANSPORT PROTEINS IN HUMAN PLACENTA

Abstract

Introduction: The placental transfer of fatty acids is a complex process mediated by specific carrier proteins from membranes and cytosol. Nevertheless, the underlying mechanisms for the preferential materno-fetal transfer of long-chain polyunsaturated fatty acids (LC-PUFA) are still poorly understood. The aim of this study is to evaluate the effects of nutritional supplements with docosahexaenoic acid (DHA) and folic acid on the placental mRNA expression of proteins that may regulate fatty acid transfer. Methods: We recruited 137 pregnant women from Granada (Spain) who received from the week 20 until delivery different nutritional supplements: placebo; MTHF supplemented with 400 ug folic acid; DHA supplemented with 500 mg DHA + 150 mg EPA; and DHA + MTHF (400ug folic acid, 500 mg DHA, 150 mg EPA ). Placental tissue was sampled at birth, fatty acid profile analyzed by gas-liquid chromatography, and mRNA expression of placental fatty acid transport proteins-1 (FATP-1) and-4 (FATP-4), heart- fatty acid binding protein (H-FABP) by real time-PCR. Results: No significant difference was found in the gene expression of fatty acid transport proteins FATP-1, FATP-4 or H-FABP among the 4 groups. There was a positive correlation of DHA % in placental phospholipids with mRNA expression of membrane proteins FATP-1 (R = +0.364, P = 0.001) and FATP-4 (R = +0.387, P < 0.001). Arachidonic acid/DHA ratio (AA/DHA) was inversely correlated with FATP-1 and FATP-4, respectively, in all placental lipid fractions except for cholesterol esters (phospholipids: R = −0.287, P = 0.007; R = −0.335, P = 0.002; NEFA: R = −0.213, P = 0.005; R = −0.235, P = 0.032; triglycerides: R= −0.310, P = 0.004; R = −0.407, P < 0.001). In contrast, the cytosolic protein H-FABP was not correlated with LC-PUFA. Conclusion: In uncomplicated pregnancies the mRNA expressions of membrane placental proteins FATP-1 and FATP-4 are related to placental accumulation of DHA and AA, respectively, whereas there is no correlation with expression of the cytosolic protein H-FABP.