Exendin-4 protects murine MIN6 pancreatic ß-cells from interleukin-1ß-induced apoptosis via the NF-κB pathway.
J Endocrinol Invest
; 36(10): 803-11, 2013 Nov.
Article
em En
| MEDLINE
| ID: mdl-23609920
ABSTRACT
BACKGROUND:
Glucagon-like peptide-1 (GLP-1) and its potent analog, exendin-4, are well known to inhibit ß- cell apoptosis and promote ß-cell proliferation. Meanwhile, cytokines, such as interleukin-1ß (IL-1ß), stimulate inducible nitric oxide synthase (iNOS) expression and nitric oxide overproduction leading to ß-cell damage. However, the protective mechanisms of GLP-1 in ß-cells exposed to cytokines have not been fully elucidated.AIMS:
In this study, the protective effects of exendin-4 on IL-1ß-induced apoptosis were investigated in murine MIN6 pancreatic ß-cells. The role of nuclear factor-κB (NF-κB) signaling in this process was also explored.METHODS:
The effects of exendin-4 pre-treatment on IL-1ß-induced apoptosis were investigated by Hoechst/PI and Annexin V/PI staining. Levels of iNOS and NF-κB proteins were investigated by Western blotting and cytoplasmic nitrite levels were determined using Griess reagent.RESULTS:
IL-1ß treatment (range, 5-40 ng/ml) for 24 h was positively correlated with nitrite production (R2=0.9668, p<0.01), a significant increase in the percentage of apoptotic cells (p<0.01) and a concomitant dose-dependent increase in cytoplasmic levels of iNOS and NF-κB p65 activation. N-acetyl- L-cysteine (NAC), NG-nitro-L-arginine methyl ester (L-NAME) and pyrrolidine dithiocarbamate (PDTC), partially rescued apoptotic ß-cells, suggesting involvement of NF-κB-iNOS-nitrite in this process. Exendin-4 (100 nM) treatment significantly decreased IL-1ß-induced apoptosis (p<0.01), downregulated NF-κB activation and subsequently decreased iNOS and nitrite levels in IL-1ß-induced ß-cells (p<0.001), in a similar manner to L-NAME, PDTC and NAC.CONCLUSIONS:
These results suggest that exendin-4 protects against IL-1ß- induced apoptosis in ß-cells via downregulation of the NF- κB-iNOS-nitrite pathway.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Peçonhas
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Transdução de Sinais
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NF-kappa B
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Apoptose
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Células Secretoras de Insulina
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Interleucina-1beta
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Hipoglicemiantes
Limite:
Animals
Idioma:
En
Revista:
J Endocrinol Invest
Ano de publicação:
2013
Tipo de documento:
Article