Abstract
Purpose: The aim of the present study was to examine changes in the expression of intracellular signal-transduction pathways, specifically mitogen-activated protein kinases, following retinal ischemia-reperfusion. Methods: Retinal ischemia was induced by elevating the intraocular pressure in porcine eyes, followed by 5, 12, or 20 h of reperfusion. The results were compared to those of the sham- operated fellow eye. The retinal arteries and neuroretina were isolated separately and examined. Tissue morphology and DNA fragmentation were studied using histology. xtracellular signal-regulated kinase 1 and 2 (ERK1/2), p38, c-junNH2-terminal kinases (JNK), and c-jun protein and mRNA expression were examined using immunofluorescence staining, western blot, and real-time PCR techniques. Results: Pyknotic cell nuclei, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells, and glial fibrillary acidic protein mRNA expression were increased in ischemia, suggesting injury. Phosphorylated ERK1/2 protein levels were increased in the neuroretina following ischemia, while mRNA levels were unaltered. p38 protein and mRNA levels were not affected by ischemia. Immunofluorescence staining for phosphorylated p38 was especially intense in the retinal blood vessels, while only weak in the neuroretina. Phosphorylated JNK protein and mRNA were slightly decreased in ischemia. Phosphorylated c-jun protein and mRNA levels were higher in the neuroretina after ischemiareperfusion. Conclusions: Retinal ischemia-reperfusion alters expression of mitogen-activated protein kinases, particularly ERK1/2, in the neuroretina and retinal arteries. The development of pharmacological treatment targeting these intracellular transduction pathways may prevent injury to the eye following retinal circulatory failure.
| Original language | English |
|---|---|
| Journal | Molecular Vision |
| Volume | 16 |
| Pages (from-to) | 392-407 |
| Number of pages | 16 |
| ISSN | 1090-0535 |
| Publication status | Published - 2010 |
Keywords
- Animals
- Blotting, Western
- Cell Nucleus
- Fluorescent Antibody Technique
- Gene Expression Regulation, Enzymologic
- Glial Fibrillary Acidic Protein
- In Situ Nick-End Labeling
- JNK Mitogen-Activated Protein Kinases
- Mitogen-Activated Protein Kinase 1
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases
- Proto-Oncogene Proteins c-jun
- RNA, Messenger
- Reperfusion Injury
- Retinal Artery
- Retinal Neurons
- Reverse Transcriptase Polymerase Chain Reaction
- Sus scrofa
- p38 Mitogen-Activated Protein Kinases