Effect of tumour necrosis factor-alpha on proliferation, activation and protein synthesis of rat hepatic stellate cells.
J Hepatol
; 27(6): 1067-80, 1997 Dec.
Article
em En
| MEDLINE
| ID: mdl-9453433
ABSTRACT
BACKGROUND/AIMS:
Hepatic stellate cells represent the principal matrix-synthesising cells of damaged liver and are targets of a number of cytokines currently under investigation. The study analyses the effects of tumour necrosis factor-alpha and interferon-gamma on proliferation, "activation" and protein synthesis of hepatic stellate cells.METHODS:
Primary cultures of hepatic stellate cells were exposed to tumour necrosis factor-alpha and interferon-gamma. Cell proliferation was studied by 3H-thymidine and bromo-deoxy-uridine incorporation. Protein synthesis was analysed using immunoprecipitation, Western- and Northern blotting techniques.RESULTS:
Proliferation of hepatic stellate cells was reduced by tumor necrosis factor-alpha and interferon-gamma, while "activation" of hepatic stellate cells as assessed by expression of smooth muscle alpha-actin and of TGF-beta/activin type I receptor was induced by tumour necrosis factor-alpha but downregulated by interferon-gamma. Tumour necrosis factor-alpha increased the synthesis of distinct extracellular matrix proteins, particularly of fibronectin and tenascin, but decreased collagen type III expression. In contrast, interferon-gamma reduced the synthesis of all connective tissue proteins tested. Among the protease inhibitors, interferon-gamma induced C1-esterase inhibitor synthesis, while tumour necrosis factor-alpha stimulated plasminogen activator inhibitor type 1 production.CONCLUSIONS:
Tumour necrosis factor-alpha and interferon-gamma decrease proliferation of hepatic stellate cells, while "activation" of hepatic stellate cells and synthesis of proteins involved in matrix metabolism are regulated in a differential, cytokine-specific manner, suggesting that both cytokines play an important role in liver repair.
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Base de dados:
MEDLINE
Assunto principal:
Inibidores de Proteases
/
Proteínas da Matriz Extracelular
/
Fator de Necrose Tumoral alfa
/
Adipócitos
/
Fígado
Limite:
Animals
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article