ISSN:
1432-0428
Schlagwort(e):
Keywords Type I diabetes
;
interferon-γ
;
transgenic mice
;
apoptosis
;
insulin secretion
;
tumour necrosis factor.
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Abstract Aims/hypothesis. To examine whether interferon-γ destroys islet beta cells directly or indirectly through lymphocyte activation, or whether direct action of interferon-γ on beta cells by itself induces diabetes without insulitis. Methods. To avoid possible nonspecific breakdown of beta cells by transgenic overexpression of interferon-γ by the insulin promoter, we generated transgenic mice expressing interferon-γ under the control of rat glucagon promoter (RGP-IFN-γ-Tg mice). Results. The absence of insulitis in RGP-IFN-γ-Tg mice enabled us to investigate the direct effects of paracrine interferon-γ. In RGP-IFN-γ-Tg mice, serum concentrations of interferon-γ and tumour necrosis factor-α (TNF-α) were 50 and 6 times higher than those in their littermates, respectively, and glucose-responsive insulin secretion decreased to one-half the level of that in the littermates. Transgenic interferon-γ induced remodelling of beta cells where apoptosis of many beta cells was compensated by their vigorous regeneration and diabetes did not occur in most of the RGP-IFN-γ-Tg mice. Conclusion/interpretation. Interferon-γ alone is insufficient for the complete destruction of beta cells in vivo, and factors other than interferon-γ including activated lymphocytes or other cytokines, are necessary in addition to interferon-γ for the development of Type I (insulin-dependent) diabetes mellitus. [Diabetologia (1999) 42: 566–573]
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s001250051196
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