A new fluorescent histological marker for ischemic neurons, EA 50: correlated with Fos and Jun/AP-1 immunoreactivity.
Cerebral ischemia/hypoxia induces ischemic neuronal changes characterized by nuclear pyknosis, cytoplasmic shrinkage, and basophilia. The ischemic neurons were shown to exhibit strong and persistent c-fos proto-oncogene. The ischemic neuronal changes and c-fos expression are thought to be the consequence of release of excessive glutamate by the ischemic neurons. In the present study, we investigated with immunohisto-chemistry the subcellular distribution of Fos and Jun/AP-1, the protein products of c-fos and c-jun proto-oncogenes, and compared them with histological changes shown by hematoxylin-eosin and by EA 50 stains. The latter is a stain mixture used traditionally in the Papani-colaou procedure and has a specific affinity for ischemic neurons. The active ingredient is eosin Y, a tetrabrominated derivative of fluorescein. With EA 50, the ischemic neurons stain red and emit a yellow fluorescence, while the non-ischemic neurons are green and non-fluorescent. The subcellular site of eosin Y binding corresponds with Fos and Jun/AP-1; all are concentrated in the nuclei and spread into the perikaryon, dendrites, and axons. The eosin Y-binding appears in neurons that have shown advanced ischemic changes. The dye is thus a good histological marker for damaged neurons, but requires freshly fixed tissues and paraffin sections of less than 4 microns thick. Preincubation of tissue sections in antibodies against Fos and Jun abolishes the eosin Y binding, suggesting that the dye may interact with Fos/Jun/AP-1 protein or other protein products in the ischemic neurons.
Chen
H H
HH
Department of Neurosurgery, National Cheng Kung University, Medical College, Tainan, Taiwan, Republic of China.
Liu
H M
HM
D000818:Animals; D001344:Autopsy; D015415:Biomarkers; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D002531:Cerebellum / Q000378:metabolism / Q000473:pathology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000737:chemistry; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013194:Staining and Labeling / Q000379:methods*
D015415:Biomarkers; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun