Insights from knock-out models concerning postischemic release of TNFα from isolated mouse hearts
| Autor: | J.-C. Reil, Stefanie Gilles, L.M. Matrisian, H. Drexler, Bernhard F. Becker, Stefan Zahler, Andreas Brandl, Ulrich Welsch, L. Hültner |
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| Rok vydání: | 2007 |
| Předmět: |
Male
medicine.medical_specialty Heart Ventricles medicine.medical_treatment Myocardial Ischemia Ischemia In Vitro Techniques Cycloheximide Histamine Release Mice chemistry.chemical_compound Internal medicine medicine Animals Mast Cells Receptor Interleukin 6 Molecular Biology Mice Knockout Protein Synthesis Inhibitors biology Interleukin-6 Tumor Necrosis Factor-alpha Myocardium Cardiac muscle Heart medicine.disease Mast cell Mice Inbred C57BL Cytokine medicine.anatomical_structure Endocrinology chemistry Receptors Tumor Necrosis Factor Type I Matrix Metalloproteinase 7 Immunology biology.protein Tumor necrosis factor alpha Cardiology and Cardiovascular Medicine |
| Zdroj: | Journal of Molecular and Cellular Cardiology. 42:133-141 |
| ISSN: | 0022-2828 |
| Popis: | The inflammatory cytokine tumor necrosis factor alpha (TNFalpha) is controversially discussed in ischemia/reperfusion damage of the heart. Purpose of this study was to elucidate cellular sources of TNFalpha and parameters which possibly influence its release in the heart following ischemia. Isolated hearts of mice were subjected to 15 min of global ischemia and 90 min of reperfusion. We employed hearts of various mice knock-out strains (interleukin-6(-/-), matrix metalloprotease-7(-/-), mast-cell deficient WBB6F1-Kit(W)/Kit(W-v), TNF-R1(-/-)) and wildtype mice, the latter perfused without and with infusion of cycloheximide or TNFalpha-cleaving-enzyme inhibitor (TAPI-2). Normoxic control hearts showed basal release of TNFalpha during the whole experiment. Immunohistology identified cardiac mast cells, macrophages and endothelial cells as main sources. TNFalpha release was stimulated during postischemic reperfusion, occurring in a two-peak pattern: directly after ischemia (0-10 min) and again after 60-90 min. The first peak mainly reflects tissue washout of TNFalpha accumulated during ischemia. The second, protracted peak arose continuously from the basal level and was abolished by protein synthesis inhibitor cycloheximide. Both properties are characteristic for de novo synthesis of TNFalpha, e.g., in cardiac muscle cells. However, immunohistological staining for TNFalpha failed in cardiomyocytes after 90 min of reperfusion. In contrast to hearts of TNF-R1(-/-) and Kit(W/W-v)-mice, those of IL-6(-/-) and MMP-7(-/-) mice lacked the late TNFalpha peak. TAPI did not suppress release of TNFalpha. While autostimulation via TNF-R1 also does not seem obligatory and mast cell can be ignored as source of the second peak, IL-6 may support de novo synthesis of TNFalpha. Additionally, TNFalpha release may essentially involve cleavage of membrane bound TNFalpha by MMP-7. |
| Databáze: | OpenAIRE |
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