A single high dose of dexamethasone increases GAP-43 and synaptophysin in the hippocampus of aged rats
| Autor: | Nela Puškaš, Selma Kanazir, Ivan Zaletel, Milka Perovic, Sabera Ruzdijic, Vesna Tesic, Mirna Jovanović |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Agonist Male medicine.medical_specialty Aging medicine.drug_class Synaptophysin GAP-43 cleavage Biology Hippocampal formation Biochemistry Hippocampus Dexamethasone 03 medical and health sciences 0302 clinical medicine Endocrinology Glucocorticoid receptor GAP-43 Protein Western blot Internal medicine Genetics medicine Hippocampus (mythology) Animals GLCM texture analysis Phosphorylation Rats Wistar Molecular Biology Glucocorticoids medicine.diagnostic_test Calpain Age Factors Cell Biology Up-Regulation 030104 developmental biology αII-spectrin cleavage Proteolysis biology.protein 030217 neurology & neurosurgery GAP-43 phosphorylation medicine.drug |
| Zdroj: | Experimental Gerontology |
| Popis: | The administration of dexamethasone, a synthetic glucocorticoid receptor agonist, has been reported to modulate cognitive performance in both animals and humans. In the present study, we demonstrate the effects of a single high dose of dexamethasone on the expression and distribution of synaptic plasticity-related proteins, growth-associated protein-43 (GAP-43) and synaptophysin, in the hippocampus of 6-, 12-, 18- and 24-month-old rats. Acute dexamethasone treatment significantly altered the expression of GAP-43 at the posttranslational level by modulating the levels of phosphorylated GAP-43 and proteolytic GAP-43-3 fragment. The effect was the most pronounced in the hippocampi of the aged animals. The total GAP-43 protein was increased only in 24-month-old dexamethasone-treated animals, and was concomitant with a decrease in calpain-mediated proteolysis. Moreover, by introducing the gray level co-occurrence matrix method, a form of texture analysis, we were able to reveal the subtle differences in the expression pattern of both GAP-43 and synaptophysin in the hippocampal subfields that were not detected by Western blot analysis alone. Therefore, the current study demonstrates, through a novel combined approach, that dexamethasone treatment significantly affects both GAP-43 and synaptophysin protein expression in the hippocampus of aged rats. |
| Databáze: | OpenAIRE |
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