Signaling of fatty acids on proliferating and differentiating SH-SY5Y cells

CARRERO RIVEROS MA; CÓRSICO B; GIMENEZ E; TOSCANI AM; FALOMIR LOCKHART LJ

Córdoba

Workshop; AvH Kolleg 2017 Córdoba; 2017

Alexander von Humboldt Club Argentina

Fatty acids (FAs) are essential cellular components and are abundant in the nervous system, acting as structural blocks for the synthesis of membrane phospholipids and performing metabolic functions. Recently, it has been shown that lipids exhibit also regulatory functions, bind to specific receptors triggering second messenger´s systems and regulating gene expression. There are two families of FAs receptors: Free Fatty Acid Receptors (FFARs), and Peroxisome Proliferator-Activated Receptor (PPARs), Central nervous system is enriched in poly-unsaturated fatty acids (PUFAs), such as arachidonic acid (AA) that participates in the regulation of membrane fluidity, axonal growth, development and inflammatory response. Alterations in lipid metabolism are associated to cognitive impairment and neurodegenerative diseases but the molecular mechanisms behind this have not yet been defined.The human cell line SH-SY5Y is often used as in vitro model of neuronal function and differentiation. They express dopaminergic markers and, as such, have been used to study Parkinson's disease. SH-SY5Y cells can be differentiated into a neuron-like phenotype by incubation with 10 M all-trans retinoic acid (RA) for 7 to 10 days. The aim of the present study is to analyze the regulatory effects of FAs in proliferation and differentiation of SH-SY5Y cells. We observed that SH-SY5Y differentiation is associated with an increase in Akt expression and phosphorylation and, unlike dopaminergic precursors, a decrease in tyrosine hydroxilase (TH). We observed that PA and AA activate Akt signaling pathway in undifferentiated cells through FFAR1 and FFAR4. Our results reveal a new role for FAs in neuronal differentiation. Although they play a key role in neuron physiology by regulating membrane fluidity, PUFAs can also activate signaling cascades downstream membrane receptors. The differentiation of SH-SY5Y cells also induces changes in their morphology. To obtain quantitative, we are currently developing a fluorescence microscopy-based assay to image single cells and quantify changes on its morphology due to the effect of FAs during. Characterization of the molecular events related to the activation of lipid receptors in the nervous system will provide us a framework to further understand their role in neurophysiology and Parkinson?s disease, where PUFAs are particularly affected by oxidative stress.