Nutritional effects on NF-kappaB/IkappaB activity in weight-gaining and -losing rats
| Autor: | Khursheed N. Jeejeebhoy, Nilima Raina |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Male
medicine.medical_specialty Immunology Spleen Biology Weight Gain Biochemistry Sepsis chemistry.chemical_compound Western blot Internal medicine Weight Loss medicine Immunology and Allergy Animals Rats Wistar Receptor Molecular Biology Lung medicine.diagnostic_test Tumor Necrosis Factor-alpha Myocardium NF-kappa B NF-κB Hematology DNA medicine.disease Rats IκBα Endocrinology medicine.anatomical_structure chemistry Tumor necrosis factor alpha I-kappa B Proteins Protein Binding |
| Zdroj: | Cytokine. 22(6) |
| ISSN: | 1043-4666 |
| Popis: | Background: We had previously reported metabolic abnormalities in TNF-treated weight-gaining (WG) rats, associated with increased soluble and membrane TNF receptors. Objective: On the basis of these findings, we hypothesized that stabilization of TNF in circulation in WG animals by these receptors augmented the action of TNF. TNF influences cellular function through the activation of NF-κB, by its release from IκBα and translocation to the nucleus where it regulates gene transcription. This study was designed to determine whether NF-κB binding was increased in WG rats in comparison with weight-losing (WL) rats. Design: Twenty two male Wistar rats weighing 200–220 g were fed a liquid-defined formula diet for 10 days and divided as follows: (i) WG rats ( n =11) receiving an energy density of 0.35 MJ per 60 ml and (ii) WL rats ( n =11) receiving an energy density of 0.09 MJ per 60 ml. Nuclear extracts from heart, liver, lung, spleen and gastrocnemius were used for NF-κB measurements by electrophoretic mobility shift assay. Tissue lysates from heart and lung were used for IκBα measurements by Western blot analysis. Results: There was increased NF-κB binding in the lung and heart extracts of the WG rats as compared with WL rats. There was no difference in the binding activity between WG and WL rats in the spleen, liver and gastrocnemius extracts. In lung and heart lysates, IκBα protein expression was decreased in WG rats as compared with the WL rats. We conclude that there is increased organ-specific TNF activity in WG rats because of increased binding of NF-κB to the nucleus and reduced IκBα levels in the lung and heart. Conclusions: The findings are consistent with increased TNF activity resulting in the release of NF-κB from the NF-κB/IκBα complex and translocation to the nucleus. The nuclear translocation of NF-κB observed in the heart and lung suggests that nutrition may influence the action of TNF in these vital organs in sepsis. This finding is potentially of great significance, as pulmonary and cardiac failure are the main causes of death in sepsis. |
| Databáze: | OpenAIRE |
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