Excitatory amino acid-induced AP-1 DNA binding activity in müller glia

✍ Scribed by A. M. López-Colomé; J. Murbartián; Dr. Arturo Ortega

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 540 KB
• Volume: 41
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490410205

✦ Synopsis

The effect of L-glutamate (L-Glu) and its structural analogs N-methyl-D-aspartate (NMDA), quisqualate (QA), and kainate (KA) on the DNA binding activity of the Activator Protein 1 (AP-1) and the Ca*+/cAMP Responsive Element Binding Protein (CREB) families of transcription factors was examined in cultured chick retinal Muller glia cells. L-Glu, NMDA, and KA evoked a dose and time dependent increase in AP-1 DNA binding activity and had no effect on CREB binding. The order of potency for stimulating AP-1 DNA binding was NMDAZGlu>KA>>QA. L-Glu responses were partially blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and by 3-[RS)-2-carboxypiperazin-4-yl)]-propyl-l-phosphonate (CPP) indicating that the increase in DNA binding is mediated both by an a-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/Iow affinity KA and a NMDA subtypes of L-Glu receptors. Since Muller glia L-Glu receptors are probably mediators of the efficacy of the excitatory transmission in the retina, the present findings suggest that a stimulustranscription coupling triggered by L-Glu in the glial cells might have a role in the long-term modulation of these synapses.