Protein kinase B/Akt signalling is required for palmitate-induced beta-cell lipotoxicity.
Diabetes Obes Metab
; 8(2): 228-33, 2006 Mar.
Article
in En
| MEDLINE
| ID: mdl-16448528
ABSTRACT
AIM:
This study was conducted to clarify cell death and survival signals in pancreatic beta-cell lipotoxicity.METHODS:
Rat insulinoma INS-1 cells, with or without expression of dominant-negative mutant of Akt (K179M), were cultured with palmitate (C160) or oleate (C181) and cell numbers were determined by 0.2% eosin dye exclusion assay. The Akt activity was determined by anti-3'-phospho-inositide-dependent protein kinase (Akt)/protein kinase B (PKB) or anti-phospho-Akt (Serine 473) immunoblotting, and nuclear protein nuclear factor-kB (NF-kappaB)-binding activity was by supershift analysis.RESULTS:
Twenty-four hours treatment with palmitate increased the INS-1 cell number at 0.1-0.2 mM but decreased the cell number at 0.5-1 mM. Oleate did not affect cell number at 0.1-1.0 mM. Palmitate dose-dependently increased phosphorylation of 473th serine in Akt/PKB. The K179M form of Akt/PKB abolished palmitate-induced cell proliferation at the low dose and death at the high dose. Nuclear protein NF-kappaB binding was enhanced at 0.2 and 0.5 mM of palmitate but decreased at 1.0 mM.CONCLUSION:
Results suggest that Akt/PKB signalling is involved in palmitate-induced cell death and survival of pancreatic beta cell.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Palmitic Acid
/
Enzyme Inhibitors
/
Insulin-Secreting Cells
/
Proto-Oncogene Proteins c-akt
Limits:
Animals
Language:
En
Journal:
Diabetes Obes Metab
Journal subject:
ENDOCRINOLOGIA
/
METABOLISMO
Year:
2006
Document type:
Article
Affiliation country:
Japón