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Nitric oxide regulates cell survival in purified cultures of avian retinal neurons: involvement of multiple transduction pathways.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Mejía-García, Telmo A. Paes-De-Carvalho, Roberto |
| Copyright Year | 2007 |
| Abstract | Nitric oxide (NO) is an important signaling molecule in the CNS, regulating neuronal survival, proliferation and differentiation. Here, we explored the mechanism by which NO, produced from the NO donor S-nitroso-acetyl-d-l-penicillamine (SNAP), exerts its neuroprotective effect in purified cultures of chick retinal neurons. Cultures prepared from 8-day-old chick embryo retinas and incubated for 24 h (1 day in culture, C1) were treated or not with SNAP, incubated for a further 72 h (up to 4 days in culture, C4), fixed, and the number of cells estimated, or processed for cell death estimation, by measuring the reduction of the metabolic dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Experimental cultures were run in parallel but were re-fed with fresh medium in the absence or presence of SNAP at culture day 3 (C3), incubated for a further 24 h up to C4, then fixed or processed for the MTT assay. Previous studies showed that the re-feeding procedure promotes extensive cell death. SNAP prevented this death in a concentration- and time-dependent manner through the activation of soluble guanylate cyclase; this protection was significantly reversed by the enzyme inhibitors 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ) or LY83583, and mimicked by 8-bromo cyclic guanosine 5'-phosphate (8Br-cGMP) (GMP) or 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole (YC-1), guanylate cyclase activators. The effect was blocked by the NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO). The effect of NO was also suppressed by LY294002, Wortmannin, PD98059, KN93 or H89, indicating the involvement, respectively, of phosphatidylinositol-3 kinase, extracellular-regulated kinases, calmodulin-dependent kinases and protein kinase A signaling pathways. NO also induced a significant increase of neurite outgrowth, indicative of neuronal differentiation, and blocked cell death induced by hydrogen peroxide. Cyclosporin A, an inhibitor of the mitochondrial permeability transition pore considered an important mediator of apoptosis and necrosis, as well as boc-aspartyl (OMe) fluoromethylketone (BAF), a caspase inhibitor, also blocked cell death induced by re-feeding the cultures. These findings demonstrate that NO inhibits apoptosis of retinal neurons in a cGMP/protein kinase G (PKG)-dependent way, and strengthens the notion that NO plays an important role during CNS development. |
| Starting Page | 1 |
| Ending Page | 4 |
| Page Count | 4 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.uff.br/neuroimuno/Telmo.pdf |
| PubMed reference number | 17116229v1 |
| Volume Number | 100 |
| Issue Number | 2 |
| Journal | Journal of neurochemistry |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | 1-Phosphatidylinositol 3-Kinase Apoptosis Aves Baker's Antifol Calmodulin 1 Caspase Inhibitors Cell Death Cell Survival Cessation of life Chick Embryo Cyclic GMP Cyclic GMP-Dependent Protein Kinases Cyclosporine Dyes Gas Scavengers Guanosine Monophosphate Guanylate Cyclase H 89 Hydrogen Peroxide LY 294002 LY 83583 Mediator brand of benfluorex hydrochloride Metabolic Process, Cellular Necrosis Neuronal Outgrowth Nitric Oxide Otitis Media with Effusion PD 98059 Penicillamine Peroxides Protein D-Aspartate-L-Isoaspartate Methyltransferase Retina Retinal Neurons Retinaldehyde incubated soluble guanylyl cyclase transduction wortmannin |
| Content Type | Text |
| Resource Type | Article |
