Light exposure activates retina ganglion cell lysophosphatidic acid acyltransferase and phosphatidic acid phosphatase by a c-Fos-dependent mechanism

DE ARRIBA CERPA, G.A.; GUIDO, M.; BUSSOLINO, D.F.; PASQUARÉ, S.J.; CASTAGNET, P.I.; GIUSTO, N.M.; CACPUTTO, B.L.

JOURNAL OF NEUROCHEMISTRY

WILEY-BLACKWELL PUBLISHING, INC

Año: 1999 vol. 73 p. 1223 - 1235

0022-3042

Abstract: We previously reported that the biosynthesis of phospholipids in the avian retina is altered by light stimulation, increasing significantly in ganglion cells in light and in photoreceptor cells in dark. In the present work, we have determined that light significantly increases theincorporation of [3H]glycerol into retina ganglion cell glycerophospholipids in vivo by a Fos-dependent mechanism because an oligonucleotide antisense to c-fos mRNA substantially blocked the light–dark differences. We also studied in vitro the enzyme activities of phosphatidatephosphohydrolase (PAPase), lysophosphatidate acyltransferase (AT II), and phosphatidylserine synthase from retinas of chickens exposed to light or dark. Higher PAPase I and AT II activities were found in incubations of retinal ganglion cells from animals exposed to light; no increase was observed in preparations obtained from light-exposed animals treated with the c-fos antisenseoligonucleotide. No light–dark differences were found in phosphatidylserine synthase activity. These findings support the idea that a coordinated photic regulation of PAPase I and AT II is taking place in retina ganglion cells. This constitutes a reasonable mechanism to obtain anoverall increased synthesis of glycerophospholipids in stimulated cells that is mediated by the expression of Fos-like proteins.