Regulation of neurite outgrowth from differentiated human neuroepithelial cells: a comparison of the activities of prothrombin and thrombin
| ISSN: | 0264-6021 |
|---|---|
| Přístupová URL adresa: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4f289bd5527e6722f39f86155be74af8 https://pubmed.ncbi.nlm.nih.gov/8948457 |
| Rights: | OPEN |
| Přírůstkové číslo: | edsair.doi.dedup.....4f289bd5527e6722f39f86155be74af8 |
| Autor: | G R Brown, C J Campbell, Phillip H. Gallimore, Michael Finney, T R V Pagliuca, D P Brant, Christopher J. Kirk, Andrew S. Turnell, Richard J. Grand, Robert H. Michell |
| Rok vydání: | 1995 |
| Předmět: |
Neurite
Inositol Phosphates Blotting Western Hirudin Biology Phosphatidylinositols Biochemistry Dephosphorylation Phosphatidylinositol 3-Kinases Thrombin Thrombin receptor medicine Neurites Humans Phosphorylation Molecular Biology Cells Cultured Cell Differentiation Cell Biology Hirudins Protein-Tyrosine Kinases Molecular biology Phosphotransferases (Alcohol Group Acceptor) Calcium Prothrombin Tyrosine kinase Intracellular medicine.drug circulatory and respiratory physiology Research Article |
| Zdroj: | The Biochemical journal. 308 |
| ISSN: | 0264-6021 |
| Popis: | The mechanism by which thrombin and prothrombin control neurite retraction was studied in Ad12E1HER10 human neuroepithelial cells. Morphological changes in differentiated cells were apparent within minutes of the addition of very low concentrations of thrombin (3 pM). Higher concentrations (2 nM) of prothrombin were required to elicit a similar response. Doses of thrombin and prothrombin sufficient to cause neurite retraction stimulated protein tyrosine kinase activity. Protein tyrosine kinase activation also correlated positively with thrombin- and prothrombin-induced phosphoinositide 3-kinase activation and InsP6 dephosphorylation. However, thrombin-stimulated Ins(1,4,5)P3 generation and intracellular Ca2+ mobilization only occurred at concentrations in excess of those needed to induce retraction. No fluctuations in Ins(1,4,5)P3 were detected after stimulation with prothrombin, and no rapid synchronized release of Ca2+ was observed, even at very high concentrations. Prothrombin did, however, cause small oscillations in the intracellular Ca2+ concentration, similar to those produced by low concentrations of thrombin, after approximately 30 min. We conclude that prothrombin- and thrombin-induced neurite retractions are not dependent on PtdIns(4,5)P2 and Ca2+ mobilization, but are more probably mediated through an effector mechanism involving protein tyrosine kinase activation. No intracellular Ca2+ mobilization, protein tyrosine kinase activity or neurite retraction was observed after treatment of cells with proteolytically inactive mutant thrombin (S205-->A). Prothrombin-mediated intracellular Ca2+ mobilization and neurite retraction were inhibited by hirudin, which was shown to interact with thrombin but not prothrombin. It is concluded that cleavage of prothrombin to thrombin is a necessary prerequisite for biological activity on differentiated Ad12E1HER10 cells and that differences in agonist concentration are capable of coupling the thrombin receptor to different pathways within the cell. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|