Effect of low-protein diet and protein supplementation on the expressions of TNF-alpha, TNFR-I, and TNFR-II in organs and muscle of LPS-injected rats
| Autor: | Khursheed N. Jeejeebhoy, Nilima Raina |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Lipopolysaccharides
Male medicine.medical_specialty Lipopolysaccharide Physiology Endocrinology Diabetes and Metabolism medicine.medical_treatment Biology Injections Intramuscular Receptors Tumor Necrosis Factor chemistry.chemical_compound Low-protein diet Antigen Antigens CD Physiology (medical) Internal medicine medicine Diet Protein-Restricted Animals Receptors Tumor Necrosis Factor Type II Rats Wistar Receptor Muscle Skeletal Tumor Necrosis Factor-alpha Protein supplementation Rats Endocrinology Cytokine chemistry Gene Expression Regulation Liver Organ Specificity Receptors Tumor Necrosis Factor Type I Dietary Supplements Tumor necrosis factor alpha Dietary Proteins Tumor necrosis factor receptor Spleen |
| Zdroj: | American journal of physiology. Endocrinology and metabolism. 286(3) |
| ISSN: | 0193-1849 |
| Popis: | Previous studies had shown that increasing energy intake in anorexic TNF-alpha-treated rats increased morbidity due to stabilization of TNF activity by soluble and membrane TNF receptors (TNFR). Although protein supplementation reduces septic morbidity, its effect on TNF and TNFR is unknown. To determine the effect of low protein intake and supplementation on TNF and TNFR, 30 male Wistar rats weighing 250 g were fed a liquid defined-formula diet for 10 days and randomly allocated to 1) controls (C; n = 6), receiving normal energy and protein energy density of 0.047 MJ/60 ml + normal saline (NS); 2) low protein (LP; n = 6), receiving normal energy but a reduced protein-energy density of 0.012 MJ/60 ml + LPS; 3) refeeding (RF; n = 6), initially depleted on low-protein diet (10 days) and then repleted on normal protein (10 days) while receiving LPS; and 4) pair fed (P-F; n = 12), individual P-F rats being paired with individual LP or RF rats receiving NS. Protein and mRNA expression of TNF-alpha, TNFR-I, and TNFR-II in liver, spleen, and gastrocnemius were measured by Western blot and RT-PCR, respectively. In liver, the changes in TNF-alpha, TNFR-I, and TNFR-II were translational, whereas in spleen the effects were due to a combination of transcription and translation. In gastrocnemius, the effects were transcriptional/translational for TNFRs. In contrast, TNF-alpha mRNA was significantly increased, but TNF-alpha protein expression was reduced in LP rats compared with C and RF groups. In conclusion, protein deficiency in endotoxic rats increases the expression of TNFR-I and TNFR-II in all organs studied and TNF-alpha in selected ones. This increase is suppressed by refeeding protein. A differential pattern between translation and transcription of TNF-alpha and its receptors is present. Our data suggest that protein restriction may be deleterious in sepsis. |
| Databáze: | OpenAIRE |
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