Irradiation leads to apoptosis of Kupffer cells by a Hsp27-dependant pathway followed by release of TNF-α
| Autor: | Hans Christiansen, CF Hess, K. Tello, Margret Rave-Fränk, H. Gürleyen, Bernhard Saile, Giuliano Ramadori, Joszef Dudas |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
Male
Programmed cell death Cell Survival Kupffer Cells Cell HSP27 Heat-Shock Proteins Biophysics Apoptosis Biology digestive system 03 medical and health sciences 0302 clinical medicine Hsp27 Downregulation and upregulation Environmental Science(all) Heat shock protein medicine Animals Rats Wistar Cells Cultured Heat-Shock Proteins bcl-2-Associated X Protein 030304 developmental biology General Environmental Science Original Paper 0303 health sciences Radiation Tumor Necrosis Factor-alpha Kupffer cell Molecular biology Neoplasm Proteins Rats Cell biology medicine.anatomical_structure Caspases 030220 oncology & carcinogenesis biology.protein Tumor necrosis factor alpha |
| Zdroj: | Radiation and Environmental Biophysics |
| ISSN: | 0301-634X |
| DOI: | 10.1007/s00411-008-0170-3 |
| Popis: | In a previous publication, we were able to show that irradiation of Kupffer cells, the liver resident macrophages, leads to an increased TNF-alpha concentration in the culture medium. The pathomechanisms underlying this phenomenon, however, remained to be elucidated. Here, we show that following irradiation of Kupffer cells, the apoptosis rate increased drastically within 48 h. At the same time, the total TNF-alpha concentration in cell lysates of Kupffer cells attached to the culture plate decreased. However, normalization of the TNF-alpha concentration with respect to cell number revealed that TNF-alpha concentration per attached cell remained constant during the observation period. Western blot analysis showed that heat shock protein 27 (Hsp27) is strongly downregulated and bax is upregulated in irradiated Kupffer cells as compared to sham-irradiated cells. Overexpression of Hsp27 in Kupffer cells was shown to prevent the effect of irradiation on bax expression, apoptosis and, at the same time, on increase of TNF-alpha concentration in the Kupffer cell medium. We conclude that irradiation of Kupffer cells leads to apoptosis because of downregulation of Hsp27 and consecutive upregulation of bax expression. Furthermore, we suggest that apoptosis of Kupffer cells leads to an increase of TNF-alpha concentration in the culture medium which may be due to cell death rather than active release or synthesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|