The effects of insulin and gliclazide therapy on endoplasmic reticulum stress and insulin sensitivity in liver of type 2 diabetic rats
10.3760/cma.j.issn.0578-1426.2012.08.016
- VernacularTitle:胰岛素和格列齐特对糖尿病大鼠肝脏内质网应激和胰岛素敏感性的影响
- Author:
Weiping SUN
;
Yan BI
;
Hua LIANG
;
Mengyin CAI
;
Xiang CHEN
;
Yanhua ZHU
;
Lizhen LIAO
;
Jianping WENG
- Publication Type:Journal Article
- Keywords:
Insulin;
Diabetes mellitus,type 2;
Endoplasmic reticulum;
Stress;
Insulin sensitivity
- From:
Chinese Journal of Internal Medicine
2012;51(8):638-641
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of insulin and gliclazide therapy on endoplasmic reticulum (ER) stress and insulin sensitivity in the liver of type 2 diabetic rats.Methods A high fat diet plus a low-dose of streptozotocin was implemented to create a type 2 diabetic rats which were randomly divided into diabetes mellitus (DM) group,insulin treatment (INS) group and gliclazide treatment (GT)group; and healthy rats were as normal control group.Diabetic rats in INS and GT groups were given neutral protamine hagedorn (NPH) insulin and gliclazide respectively for 3 weeks.Protein expression levels of immunoglobulin binding protein (Bip),spliced X-box binding protein 1 (XBP-ls),phosphorylated c-Jun on serine 73 (p-c-Jun),phosphorylated insulin receptor substrate 1 on serine 307 (p-IRS-1),and glucose-6-phosphatase (G6Pase) in liver homogenate were detected by Western blotting.Results Compared with the normal rats,Bip and XBP-Is in the DM group were up-regulated (0.28 ±0.07 vs 0.90 ±0.10 for Bip;0.41 ± 0.07 vs 0.95 ±0.07 for XBP-1 s; both P ＜ 0.01 ) ; p-c-Jun (0.59 ± 0.18 vs 1.94 ± 0.03 ),p-IRS-1( 1.73 ± 0.18 vs 5.32 ± 0.22) and G6Pase (0.11 ± 0.01 vs 0.45 ± 0.01 ) were increased ( all P values ＜0.01 ).In the INS group,all of aforementioned changes were reversed (0.90 ± 0.10 vs 0.25 ± 0.04 for Bip; 0.95 ±0.07 vs 0.47 ±0.01 for XBP-1s; 1.94 ± 0.03 vs 0.50 ±0.10 for p-c-Jun; 5.32 ± 0.22 vs 1.59 ±0.32 for p-IRS-1 ; 0.45 ±0.01 vs 0.15 ±0.02 for G6Pase,all P values ＜0.01 ).In the GT group,all of aforementioned changes were also attenuated ( 0.90 ± 0.10 vs 0.53 ± 00.02 for Bip ; 0.95 ± 0.07 vs 0.78±0.02 for XBP-1s; 1.94 ±0.03 vs 1.33 ±0.11 for p-c-Jun; 5.32 ±0.22 vs 3.13 ±0.02 for p-IRS-1; 0.45 ± 0.01 vs 0.25 ± 0.01 for G6Pase,all P values ＜ 0.05).Furthermore,all of aforementioned protein levels were down-regulated more obviously in the INS group comparing to the GT group ( all P values ＜ 0.01 ).Conclusions Both insulin and gliclazide therapy could relieve ER stress and e-Jun N-terminal kinase activity and improved insulin sensitivity.The effect of insulin on Bip,XBP-1s,p-c-Jun,p-IRS-1 and G6Pase protein expressions is more obvious than that of glilcazide,which indicates besides lowering glucose,insulin might have protective effects of anti-inflammation,anti-oxidative stress or stimulation of lipid redistribution.
