AK098656: a new biomarker of coronary stenosis severity in hypertensive and coronary heart disease patients.

BACKGROUND: AK098656 may be an adverse factor for coronary heart disease (CHD), especially in patients with hypertension. This study aimed to analyze the effect of AK098656 on CHD and CHD with various complications. METHODS: A total of 117 CHD patients and 27 healthy control subjects were enrolled in the study. Plasma AK098656 expression was determined using the quantitative real-time polymerase chain reaction. Student's t-test was used to compare AK098656 expression levels in different groups. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to quantify the discrimination ability between CHD patients and health controls and between CHD and CHD + complications patients. The relationship between AK098656 and coronary stenosis was analyzed using Spearman's correlation. RESULTS: AK098656 expression was remarkably higher in CHD patients than in healthy controls (P = 0.03). The ROC curve revealed an effective predictive AK098656 expression value for CHD risk, with an AUC of 0.656 (95% CI 0.501-0.809). Moreover, AK098656 expression was increased in CHD + complications patients compared to CHD patients alone (P = 0.005), especially in patients with hypertension (CHD + hHTN, P = 0.030). The ROC curve revealed a predictive AK098656 prognostic value for discriminating between CHD and CHD + hHTN patients, with an AUC of 0.666 (95% CI 0.528-0.805). There was no significant difference in AK098656 expression in CHD patients with diabetes mellitus compared to CHD patients alone. In addition, AK098656 expression in CHD patients was positively correlated with stenosis severity (R = 0.261, P = 0.006). CONCLUSION: AK098656 expression was significantly increased in patients with CHD, especially those with hypertension, and its expression level was positively correlated with the degree of coronary stenosis. This implied that AK098656 may be a risk factor for CHD and can potentially be applied in clinical diagnosis or provide a novel target for treatment.

Dipeptidyl peptidase-4 (DPP4) inhibitor sitagliptin alleviates liver inflammation of diabetic mice by acting as a ROS scavenger and inhibiting the NFκB pathway.

As a common chronic metabolic disease, the development of diabetes mellitus (DM) may also be accompanied by liver damage and inflammatory disorders. Sitagliptin is an inhibitor of dipeptidyl peptidase-4 (DPP4, also known as CD26), which is clinically used for DM treatment. However, the mechanism of sitagliptin's efficiency in liver diseases is largely unknown. In this study, mice suffering from streptozotocin (STZ) exhibit elevated liver DPP4 expression and activity, as well as inflammatory and chronic liver injury phenotype, whereas specifically inhibiting the activity of DPP4 in mouse liver tissues and hepatocytes by sitagliptin contributes to decreased cytokines, oxidative stress, cell apoptosis, and inflammation in STZ-induced diabetic mice. Moreover, sitagliptin reduced TNFα or LPS-induced cellular reactive oxygen species (ROS) level, cell apoptosis, and protein expression in the NFκB signaling pathway in HepG2 cells or primary mouse hepatocytes. Altogether, our study confirms that sitagliptin may protect liver tissue by alleviating ROS production and NFκB signaling activation, providing a putative mechanism for preventing the development of diabetic liver disease.

MicroRNA-20a-5p Ameliorates Non-alcoholic Fatty Liver Disease via Inhibiting the Expression of CD36.

Fatty acid translocase CD36 (CD36) plays an important role in the initiation and pathogenesis of chronic liver disease and non-alcoholic fatty liver disease (NAFLD). The purpose of this study is to investigate the regulation of microRNA-20a-5p (miR-20a-5p) on CD36 in the pathogenesis of NAFLD. Human plasma samples were obtained from NAFLD patients and healthy controls. Mice were fed with high-fat diet to induce an in vivo NAFLD model. Histology staining was performed to examine the morphology and lipid deposition of mouse liver tissue. Real-time PCR, dual-luciferase assay, and western blotting were employed to detect the relationship between miR-20a-5p and CD36. The expression level of miR-20a-5p was decreased in NAFLD patients, HFD mice, and free fatty acid (FFA)-treated HepG2 cells or primary mouse hepatocytes, accompanied by increased lipid production in hepatocytes. MiR-20a-5p suppressed the expression of CD36 to reduce lipid accumulation via binding to its 3'-untranslated region (UTR). However, under the condition of interference with CD36, further inhibition of miR-20a-5p would not cause lipid over-accumulation. In this study, we found that miR-20a-5p played a protective role in lipid metabolic disorders of NAFLD by targeting CD36, which indicated the prospect of miR-20a-5p as a biomarker and treatment target for NAFLD.

Angiopoietin-like 3 Is a Potential Biomarker for Retinopathy in Type 2 Diabetic Patients.

PURPOSE: To investigate whether angiopoietin-like 3 (ANGPTL3) and angiopoietin-like 4 (ANGPTL4) are differentially associated with the severity of retinopathy in patients with type 2 diabetes mellitus (T2DM). DESIGN: Cross-sectional study. METHODS: Serum levels of ANGPTL3, ANGPTL4, high-sensitivity C-reactive protein (CRP), vascular adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), and vascular endothelial growth factor (VEGF) were quantified by ELISA. Retinal images were recorded to assess the grade of diabetic retinopathy (DR). Multivariable-adjusted logistic analysis was performed to estimate the association of each biomarker and DR stage. RESULTS: Among 1192 T2DM patients, 426 (35.7%) had nonproliferative diabetic retinopathy (NPDR) and 56 (4.5%) had proliferative diabetic retinopathy (PDR). After adjusting for covariables, the odds ratios expressing the risk of having DR vs no DR (n = 710 vs 482) were 1.23 (95% confidence interval [CI], 1.08-1.40, P = .002) for ANGPTL3; 0.90 (95% CI, 0.79-1.02; P = .095) for ANGPTL4; and 1.14 (95% CI, 1.00-1.29; P = .044) for VEGF. The risk of having no DR vs NPDR (n = 710 vs 426) was 1.16 (95% CI, 1.01-1.32; P = .036) for ANGPTL3; 0.90 (95% CI, 0.79-1.04; P = .15) for ANGPTL4; and 1.14 (95% CI, 1.00-1.31; P = .045) for VEGF. The odds ratios of having NPDR vs PDR (n = 426 vs 56) was 1.47 (95% CI, 1.03-2.10; P = .035) for serum ANGPTL3; 0.96 (95% CI, 0.69-1.35; P = .83) for ANGPTL4; and 1.05 (95% CI, 0.77-1.45; P = .74) for VEGF. CONCLUSIONS: ANGPTL3 is independently and strongly associated with DR progression in all stages. Blockade of ANGPTL3 signal in retina might postpone the onset and development of DR in T2DM patients.

Angiopoietin-Like Protein 4 Is a High-Density Lipoprotein (HDL) Component for HDL Metabolism and Function in Nondiabetic Participants and Type-2 Diabetic Patients.

BACKGROUND: ANGPTL4 (angiopoietin-like protein 4) is a LPL (lipoprotein lipase) inhibitor and is present in high-density lipoprotein (HDL). However, it is not defined whether ANGPTL4 in HDLs could affect HDL metabolism and function in type 2 diabetes mellitus (T2DM). METHODS AND RESULTS: ANGPTL4 levels in the circulation and HDLs were quantified in nondiabetic participants (n=201, 68.7% females) and T2DM patients (n=185, 66.5% females). HDLs were isolated from nondiabetic controls and T2DM patients to assess cholesterol efflux or subjected to endothelial lipase (EL)-overexpressed HEK293 cells for EL hydrolysis in vitro. The association between ANGPTL4 in HDLs and HDL components and function was analyzed in nondiabetic participants or diabetic patients, respectively. Plasma or HDLs of ANGPTL4+/+ and ANGPTL4-/- mice was subjected for cholesterol efflux or EL hydrolysis, respectively. ANGPTL4 levels in the plasma and HDLs were 1.7- and 2.0-fold higher in T2DM patients than nondiabetic controls, respectively (P<0.0001). Multivariable analysis demonstrated that per 1 doubling increase of ANGPTL4 levels in HDLs, the changes amounted to +0.27% cholesterol efflux (P=0.03), +0.06 µg/mL apolipoprotein A-I (P=0.09) and -9.41 µg/L serum amyloid A (P=0.02) in nondiabetic controls. In T2DM patients, the corresponding estimates were -0.06% cholesterol efflux (P=0.10), -0.06 µg/mL apolipoprotein A-I (P=0.38), and +3.64 µg/L serum amyloid A (P=0.72). HDLs isolated from ANGPTL4-/- mice showed accelerated hydrolysis by EL and reduced cholesterol efflux compared with ANGPTL4+/+ littermates. CONCLUSIONS: Physically, ANGPTL4 in HDLs protected HDLs from hydrolysis. Resulting from increased circulating ANGPTL4 levels in T2DM, ANGPTL4 levels in HDLs were elevated but with compromised inhibitory effect on EL, leading to increased HDL hydrolysis and dysfunction.

Different relationship between ANGPTL3 and HDL components in female non-diabetic subjects and type-2 diabetic patients.

BACKGROUND: Angiopoietin-like protein 3 (ANGPTL3) is a major lipoprotein regulator and shows positive correlation with high-density lipoprotein-cholesterol (HDL-c) in population studies and ANGPTL3 mutated subjects. However, no study has looked its correlation with HDL components nor with HDL function in patients with type 2 diabetes mellitus (T2DM). METHODS: We studied 298 non-diabetic subjects and 300 T2DM patients who were randomly recruited in the tertiary referral centre. Plasma levels of ANGPTL3 were quantified by ELISA. Plasma samples were fractionated to obtain HDLs. HDL components including apolipoprotein A-I (apoA-I), triglyceride, serum amyloid A (SAA), phospholipid and Sphingosine-1-phosphate were measured. HDLs were isolated from female controls and T2DM patients by ultracentrifugation to assess cholesterol efflux against HDLs. A Pearson unadjusted correlation analysis and a linear regression analysis adjusting for age, body mass index and lipid lowering drugs were performed in male or female non-diabetic participants or diabetic patients, respectively. RESULTS: We demonstrated that plasma level of ANGPTL3 was lower in female T2DM patients than female controls although no difference of ANGPTL3 levels was detected between male controls and T2DM patients. After adjusting for confounding factors, one SD increase of ANGPTL3 (164.6 ng/ml) associated with increase of 2.57 mg/dL cholesterol and 1.14 µg/mL apoA-I but decrease of 47.07 µg/L of SAA in HDL particles of non-diabetic females (p < 0.05 for cholesterol and SAA; p < 0.0001 for apoA-I). By contrast, 1-SD increase of ANGPTL3 (159.9 ng/ml) associated with increase of 1.69 mg/dl cholesterol and 1.25 µg/mL apoA-I but decrease of 11.70 µg/L of SAA in HDL particles of female diabetic patients (p < 0.05 for cholesterol; p < 0.0001 for apoA-I; p = 0.676 for SAA). Moreover, one SD increase of ANGPTL3 associated with increase of 2.11 % cholesterol efflux against HDLs in non-diabetic females (p = 0.071) but decrease of 1.46 % in female T2DM patients (p = 0.13) after adjusting for confounding factors. CONCLUSIONS: ANGPTL3 is specifically correlated with HDL-c, apoA-I, SAA and HDL function in female non-diabetic participants. The decrease of ANGPTL3 level in female T2DM patients might contribute to its weak association to HDL components and function. ANGPTL3 could be considered as a novel therapeutic target for HDL metabolism for treating diabetes.

Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs) in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF) treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on "VEGF uncoupling with nitric oxide" and "competitive angiopoietin 1/angiopoietin 2" mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics.