当前位置： SCI文献检索 > DIABETOLOGIA期刊下所有文献 > Increased insulin demand promotes while pioglitazone prevents pancreatic beta cell apoptosis in Wfs1 knockout mice.

Increased insulin demand promotes while pioglitazone prevents pancreatic beta cell apoptosis in Wfs1 knockout mice.

Abstract：

AIMS/HYPOTHESIS:The WFS1 gene encodes an endoplasmic reticulum (ER) membrane-embedded protein called Wolfram syndrome 1 protein, homozygous mutations of which cause selective beta cell loss in humans. The function(s) of this protein and the mechanism by which the mutations of this gene cause beta cell death are still not fully understood. We hypothesised that increased insulin demand as a result of obesity/insulin resistance causes ER stress in pancreatic beta cells, thereby promoting beta cell death. METHODS:We studied the effect of breeding Wfs1 ( -/- ) mice on a C57BL/6J background with mild obesity and insulin resistance, by introducing the agouti lethal yellow mutation (A ( y ) /a). We also treated the mice with pioglitazone. RESULTS:Wfs1 ( -/- ) mice bred on a C57BL/6J background rarely develop overt diabetes by 24 weeks of age, showing only mild beta cell loss. However, Wfs1 ( -/- ) A ( y ) /a mice developed selective beta cell loss and severe insulin-deficient diabetes as early as 8 weeks. This beta cell loss was due to apoptosis. In Wfs1 ( +/+ ) A ( y ) /a islets, levels of ER chaperone immunoglobulin-binding protein (BiP)/78 kDa glucose-regulated protein (GRP78) and phosphorylation of eukaryotic translation initiation factor 2, subunit alpha (eIF2alpha) apparently increased. Levels of both were further increased in Wfs1 ( -/- ) A ( y ) /a murine islets. Electron micrography revealed markedly dilated ERs in Wfs1 (-/-) A ( y ) /a murine beta cells. Interestingly, pioglitazone treatment protected beta cells from apoptosis and almost completely prevented diabetes development. CONCLUSIONS/INTERPRETATION:Wfs1-deficient beta cells are susceptible to ER stress. Increased insulin demand prompts apoptosis in such cells in vivo. Pioglitazone, remarkably, suppresses this process and prevents diabetes. As common WFS1 gene variants have recently been shown to confer a risk of type 2 diabetes, our findings may be relevant to the gradual but progressive loss of beta cells in type 2 diabetes.

journal_name

Diabetologia

journal_title

Diabetologia

authors

Akiyama M,Hatanaka M,Ohta Y,Ueda K,Yanai A,Uehara Y,Tanabe K,Tsuru M,Miyazaki M,Saeki S,Saito T,Shinoda K,Oka Y,Tanizawa Y

doi

10.1007/s00125-009-1270-6

subject

Has Abstract

pub_date

2009-04-01 00:00:00

pages

653-63

issue

eissn

0012-186X

issn

1432-0428

journal_volume

pub_type

杂志文章

在线工具

Increased insulin demand promotes while pioglitazone prevents pancreatic beta cell apoptosis in Wfs1 knockout mice.