Experimental Diabetes Research最新文献

Diabetic angiopathy including micro- and macroangiopathy is concerned with high rate of morbidity and mortality in patients with long-standing diabetes. Receptor for advanced glycation end products (RAGE) and its ligands have been considered as important pathogenic triggers for the progression of the vascular injuries in diabetes. The deleterious link between RAGE and diabetic angiopathy has been demonstrated in animal studies. Preventive and therapeutic strategies focusing on RAGE and its ligand axis may be of great importance in relieving diabetic vascular complications and reducing the burden of disease.

Background: Pentoxifylline (PTX) anti-TNF properties are known to exert hepatoprotective effects in various liver injury models. The aim of this study was to investigate whether PTX has beneficial roles in the development of methionine- and choline-deficient-(MCD-) diet-induced NAFLD SD rats in vivo and TNF-α-induced Hep3B cells in vitro.

Methods: SD Rats were classified according to diet (chow or MCD diet) and treatment (normal saline or PTX injection) over a period of 4 weeks: group I (chow + saline, n = 4), group II (chow + PTX), group III (MCD + saline), and group IV (MCD + PTX). Hep3B cells were treated with 100 ng/ml TNF-α (24 h) in the absence or presence of PTX (1 mM).

Results: PTX attenuated MCD-diet-induced serum ALT levels and hepatic steatosis. In real-time PCR and western blotting analysis, PTX decreased MCD-diet-induced TNF-alpha mRNA expression and proapoptotic unfolded protein response by ER stress (GRP78, p-eIF2, ATF4, IRE1α, CHOP, and p-JNK activation) in vivo. PTX (1 mM) reduced TNF-α-induced activation of GRP78, p-eIF2, ATF4, IRE1α, and CHOP in vitro.

Conclusion: PTX has beneficial roles in the development of MCD-diet-induced steatohepatitis through partial suppression of TNF-α and ER stress.

Obesity is recognized as a major health problem worldwide. Genetic factors play a major role in obesity, and genomewide association studies have provided evidence that several common variants within the fat mass- and obesity-associated (FTO) gene are significantly associated with obesity. Very limited data is available on FTO in the Italian population. Aims of our study are to investigate: (1) the association of FTO gene SNPs rs9939609 and rs9930506 with body mass index (BMI) and obesity-related parameters in a large cohort (n = 752) of Italian obese subjects; (2) the association between the two FTO SNPs and age of onset of obesity. Our results demonstrate a strong association between FTO SNPs rs9939609 (P < 0.043) and rs9930506 (P < 0.029) with BMI in the Italian population. FTO rs9930506 was significantly associated with higher BMI in a G allele dose-dependent manner (BMI + 1.4 kg/m² per G allele). We also observed that the association with BMI of the two FTO variants varied with age, with the carriers of the risk alleles developing an increase in body weight earlier in life. In conclusion, our study further demonstrates a role of the genetic variability in FTO on BMI in a large Italian population.

High fructose intake induces an insulin resistance state associated with metabolic syndrome (MS). The effect of vascular inflammation in this model is not completely addressed. The aim of this study was to evaluate vascular remodeling, inflammatory and oxidative stress markers, and atheroma development in high-fructose diet-induced insulin resistance of ApoE-deficient mice (ApoE-KO). Mice were fed with either a normal chow or a 10% w/v fructose (HF) in drinking water over a period of 8 weeks. Thereafter, plasma metabolic parameters, vascular remodeling, atheroma lesion size, inflammatory markers, and NAD(P)H oxidase activity in the arteries were determined. HF diet induced a marked increase in plasma glucose, insulin, and triglycerides in ApoE-KO mice, provoked vascular remodeling, enhanced expression of vascular cell-adhesion molecule-1 (VCAM-1) and matrix metalloprotease 9 (MMP-9) and enlarged atherosclerotic lesion in aortic and carotid arteries. NAD(P)H oxidase activity was enhanced by fructose intake, and this effect was attenuated by tempol, a superoxide dismutase mimetic, and losartan, an Angiotensin II receptor antagonist. Our study results show that high-fructose-induced insulin resistance promotes a proinflammatory and prooxidant state which accelerates atherosclerotic plaque formation in ApoE-KO mice.

Objective: To identify predictors of end-stage proliferative diabetic retinopathy (PDR) in a cohort of individuals with type 2 diabetes mellitus (T2DM) from the Northern Chinese Han population.

Methods: We investigated characteristics of 153 consecutive diabetic patients with end-stage PDR (62 males, 91 females), 123 consecutive PDR patients without end-stage PDR (48 males, 75 females), and 151 normal subjects (63 males, 88 females). Only one eye of each patient or healthy subject was included in this study. Univariate logistic regression models and multivariate logistic regression models were constructed to evaluate the predictors of end-stage PDR.

Results: In univariate analysis, systolic blood pressure, diastolic blood pressure, duration of diabetes, family history of T2DM, and plasminogen activator inhibitor-1 (PAI-1) were significently associated with end-stage PDR. After multivariate analysis, family history of T2DM, plasma PAI-1 levels, smoking, and duration of diabetes were four positive predictors associated with end-stage PDR.

Conclusions: Higher plasma levels of PAI-1 were associated with end-stage PDR in the Northern Chinese Han population with T2DM.

Aim: An exploration of ethnic differences in measures of oxidative stress and endothelial activation in relation to known cardiovascular risk factors within South Asians (SA) and White Europeans (WE) residing in the UK.

Methods: 202 participants within a UK multiethnic population provided biomedical and anthropometric data. Human urinary 2,3-dinor-8-iso-prostaglandin-F1α and plasma ICAM-1 were quantified as measures of oxidative stress and endothelial activation, respectively.

Results: 2,3-Dinor-8-iso-prostaglandin-F1α levels were significantly higher in the SA group compared to WE group (10.36 (95% CI: 9.09, 11.79) versus 8.46 (7.71, 9.29), P = 0.021) after adjustment for age, gender, smoking status, body weight, HbA1c, and medication. Oxidative stress was positively associated with HbA1c (β = 1.08, 95% CI:1.02, 1.14, P = 0.009), fasting (β = 1.06, 95% CI: 1.02, 1.10, P = 0.002), and 2 hr glucose (β = 1.02, 95% CI: 1.00, 1.04, P = 0.052). In each adjusted model, SA continued to have elevated levels of oxidative stress compared to WE. ICAM-1 levels were significantly higher in the composite IGR group compared to the normoglycaemic group (P < 0.001). No ethnic differences in ICAM-1 were observed.

Conclusion: These results suggest that SA are more susceptible to the detrimental effects of hyperglycaemia-induced oxidative stress at lower blood glucose thresholds than WE. Further research into the potential mechanisms involved is warranted.