VIP INDUCES GLUCOSE UPTAKE THROUGH PKA/MAPK/PI3K SIGNALING PATHWAYS AND REGULATES AMINO ACID TRANSPORT IN TROPHOBLAST CELLS

E SOCZEWSKI; C PÉREZ LEIRÓS; V HAUK; R RAMHORST; F MERECH; D PAPARINI; D VOTA

Mar del Plata

Congreso; LXIII Reunión Anual SAIC; 2018

SAIC

Appropriate trophoblast (Tb) metabolism is crucial to allow nutrient transport across the placenta. Alterations of this process may lead to placental insufficiency associated to fetal growth restriction. Glucose and amino acids are essential substrates for the placenta and the fetus and its transfer depends on specific carrier proteins such as GLUT and mainly System A (SNATs) and System L, respectively. mTOR is a serine-threonine kinase activated by PI3K pathway that regulates the expression/activation of amino acid transporters and its role on GLUT transporters in mouse skeletal muscle has been reported. The vasoactive intestinal peptide (VIP) activates cAMP/PKA, PKC and MAPK pathways. VIP expression is regulated by mTOR in central nervous system.We havepreviously demonstrated that VIP induces mTOR and GLUT1 mRNA expression as well as glucose uptake through mTOR pathways in Tb cells. Here we analyzed the mechanisms involved in VIP-mediated glucose uptake and the role of VIP in the regulation of amino acid uptake in Tb cells. We used two human Tb cell lines, Swan-71 and BeWo. SNAT1/VIP expression was evaluated by qRT-PCR and flow cytometry. Glucose uptake was measured by flow cytometry using the fluorescent analogue 2-NBDG, and System A activity by incorporation of a specific radiolabelled substrate, 14C-MeAIB, using a scintillation counter. Pharmacological inhibition of PKA and MAPK but not PKC pathways prevented VIP-mediated glucose uptake. Inhibition of PI3K also impaired VIP effect (n=5; p