A regulated secretory pathway in cultured hippocampal astrocytes
| Autor: | Patrizia Rosa, Nicoletta Corradi, Claudia Verderio, Silvia Coco, Michela Matteoli, Monique Bassetti, Elena Taverna, Federico Calegari |
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| Přispěvatelé: | Calegari, F, Coco, S, Taverna, E, Bassetti, M, Verderio, C, Corradi, N, Matteoli, M, Rosa, P |
| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: |
Population
Golgi Apparatus Golgi Apparatu Biology Cytoplasmic Granules Bradykinin Cell Fractionation Biochemistry Hippocampus PC12 Cells Exocytosis symbols.namesake Hippocampu Chromogranins Cyclic AMP Animals Calcium Signaling education Molecular Biology Secretory pathway Cells Cultured education.field_of_study Animal Ionomycin Protein Neuropeptides Granin Proteins Cell Biology Golgi apparatus Secretory Vesicle PC12 Cell Cell biology Rats Cell Compartmentation Chromogranin Neuropeptide processing Neuropeptide Astrocytes symbols Rat Tetradecanoylphorbol Acetate Cytoplasmic Granule Astrocyte |
| Popis: | Glial cells have been reported to express molecules originally discovered in neuronal and neuroendocrine cells, such as neuropeptides, neuropeptide processing enzymes, and ionic channels. To verify whether astrocytes may have regulated secretory vesicles, the primary cultures prepared from hippocampi of embryonic and neonatal rats were used to investigate the subcellular localization and secretory pathway followed by secretogranin II, a well known marker for dense-core granules. By indirect immunofluorescence, SgII was detected in a large number of cultured hippocampal astrocytes. Immunoreactivity for the granin was detected in the Golgi complex and in a population of dense-core vesicles stored in the cells. Subcellular fractionation experiments revealed that SgII was stored in a vesicle population with a density identical to that of the dense-core secretory granules present in rat pheochromocytoma cells. In line with these data, biochemical results indicated that 40-50% of secretogranin II synthesized during 18-h labeling was retained intracellularly over a 4-h chase period and released after treatment with different secretagogues. The most effective stimulus appeared to be phorbol ester in combination with ionomycin in the presence of extracellular Ca(2+), a treatment that was found to produce a large and sustained increase in intracellular calcium [Ca(2+)](i) transients. Our findings indicate that a regulated secretory pathway characterized by (i) the expression and stimulated exocytosis of a typical marker for regulated secretory granules, (ii) the presence of dense-core vesicles, and (iii) the ability to undergo [Ca(2+)](i) increase upon specific stimuli is present in cultured hippocampal astrocytes. |
| Databáze: | OpenAIRE |
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