Tumor necrosis factor-alpha acts as a complete mitogen for primary rat hepatocytes.
Am J Pathol
; 163(2): 465-76, 2003 Aug.
Article
em En
| MEDLINE
| ID: mdl-12875968
ABSTRACT
The cytokine tumor necrosis factor (TNF)-alpha has previously been shown to prime hepatocytes to a state of replicative competence, but has not been shown to act as a complete mitogen for these cells. In the present study we have altered our previously described long-term dimethyl sulfoxide culture system to exclude all known hepatocyte mitogens from the culture media and enable us to directly examine the effects of TNF-alpha on primary rat hepatocytes. We have shown that cells maintained under these culture conditions retain the biochemical and morphological features of well-differentiated hepatocytes. Treatment with TNF-alpha induced DNA synthesis relative to control, to a level not significantly different from that induced by the known hepatocyte mitogen, epidermal growth factor (EGF). Maximal DNA synthesis was induced by treatment with 250 U/ml TNF-alpha for 24 hours. Mitotic figures were observed in cultures treated with TNF-alpha or EGF but not in untreated controls. Treatment of cultures with TNF-alpha, but not EGF, induced activation of both nuclear factor-kappaB p50 homodimers and p50/p65 heterodimers. DNA synthesis induced by TNF-alpha was inhibited by treatment with transforming growth factor-beta. Based on the results of our studies, we conclude that TNF-alpha acts as a complete mitogen for rat hepatocytes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Necrose Tumoral alfa
/
Hepatócitos
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Mitógenos
Limite:
Animals
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Humans
/
Male
Idioma:
En
Revista:
Am J Pathol
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos