Molecular cues regulating glial migration: a key role for ceramide-1-phosphate?

VERA M; PRADO SPALM F.H.; SIMON M.V.; ROTSTEIN NP

Buenos Aires

Simposio; The role of glia in health and disease in the nervous system: Clinical and basic science walking together; 2017

IBRO

Molecular cues regulating glial migration: a key role for ceramide-1-phosphate?Marcela Vera, F.H. Prado Spalm, M.V. Simón and N.P. Rotstein. Instituto de Investigaciones Bioquímicas de Bahía Blanca, UNS-CONICET, Bahía Blanca, Buenos Aires, Argentina.Retina proliferative diseases are major causes of visual dysfunction. Müller glial cells (MGC), the major glial cell type in the retina, play a key role in these diseases. Most injuries to the retina induce the onset of reactive gliosis, exacerbating proliferation and migration that contribute to visual dysfunction. We have recently established that a sphingolipid, sphingosine-1-phosphate (S1P), promotes glial migration. We have now investigated whether ceramide-1-phosphate (C1P), another sphingolipid known to control proliferation and migration in several cell types, is involved in glial migration. Using pure glial cultures prepared from newborn rat retinas, and the scratch wound assay, we determined that MGC migration in controls was stimulated by exogenous addition of 10 μM C1P. To investigate whether C1P was also involved in MGC migration in controls, we first established by PCR that MGC expressed ceramide kinase (CerK), the enzyme responsible for C1P synthesis. Treatment of glial cultures with NVP231, a CerK inhibitor, completely prevented glial migration, which was not restored by exogenous addition of C1P. We then investigated the signaling pathways involved in C1P effect. Inhibiting the PI3K and the ERK/MAPK pathways, with LY294002 and U0126, respectively, decreased glial migration, both in control and C1P-treated cultures. SP6000, a Jun K inhibitor, also blocked C1P-induced glial migration. C1P activates a cytoplasmic phospholipase A2 (cPLA2) in different cell types. Pre-treatment with ATK, a cPLA2 inhibitor, markedly reduced glial migration in control and C1P-treated cultures.These results suggest that MGC synthesize C1P, which is a central cue for regulating glial cell migration through the activation of cPLA2 and the Jun K, the PI3K and the ERK/MAPK pathways.