Relationships of vascular endothelial growth factor (VEGFA) with stage of diabetic retinopathy and disease duration in patients with type 2 diabetes mellitus

Background: As there is currently an epidemic of type 2 diabetes mellitus (T2DM), increasing attention should be paid to diabetic retinopathy (DR), a major complication of the disease which can lead to disability and blindness. Increased levels of growth factors (mainly, vascular endothelial growth factor (VEGFA)), angiogenesis factors, and cytokines in the aqueous humor have been reported in DR. Purpose: To identify the relationship of VEGFA with the stage of DR and duration of disease in T2DM through (1) investigation of the effect of increased aqueous VEGFA level on DR complications and (2) estimation of the sensitivity of clinical and laboratory indicators to the amount of VEGFA in the aqueous humor. Materials and Methods: Totally, 302 persons (604 eyes) were included in the study. Patients with T2DM were divided into three groups according to the severity of DR: Group 1 (no retinopathy, 76 patients), Group 2 (non-proliferative DR, 64 patients), and Group 3 (proliferative DR, 64 patients). The control group included 98 individuals with no T2DM or DR. Aqueous humor VEGFA levels were measured using enzyme-linked immunosorbent assay kits from eBioscience. Statistical analyses were performed using SPSS 11.0, MedCalc v.15.11.0 and Medstat Software. Results: Regression analyses demonstrated that aqueous VEGFA level directly and significantly influences the stage of DR and diabetes duration at baseline (P = 2.27E-08 and P =6.15E-05, respectively). In addition, increased aqueous VEGFA levels significantly influence the probability of developing neovascularization in the ocular tissue, vitreous hemorrhage or PDR (P < 0.05). An increase in the probability of developing optic disc neovascularization, retinal neovascularization, vitreous hemorrhage, vitreoretinal neovascularization, or PDR occurs with an increase in aqueous VEGFA level above 992 pg/mL, 923 pg/mL, 1005 pg/mL, 1022 pg/mL; and 926 pg/mL, respectively. Conclusion: Elevated aqueous VEGFA levels are a potent pathogenic factor for progression of DR in patients with T2DM

The effect of N-stearoylethanolamine on adipocytes free cholesterol content and phospholipid composition in rats with obesity-induced insulin resistance

Obesity induces molecular changes that promote associated disorders, such as insulin resistance (IR) and type 2 diabetes. Low insulin sensitivity occurs primarily due to defects in the pathway of insulin action in target tissues, and there is a hypothesis that IR may originate in adipose tissue and is followed by dyslipidemia. In this study using methods of thin-layer and gas-liquid chromatography we investigated free cholesterol content and phospholipid composition of adipocytes of obesity-induced IR rats and its changes induced by the N-stearoylethanolamine (NSE) administration. The results we obtained demonstrated that free cholesterol content significantly increased in adipocytes of IR rats compared to control. The analysis of phospholipid composition indicated a reduction of phosphatidylcholine and the total content of phosphatidylinositol with phosphatidylserine, whereas the content of lysophosphatidylcholine, sphingomyelin and phosphatidylethanolamine increased in IR group compared to control. NSE administration caused a statistically significant decrease in total cholesterol level and had a considerable effect on normalization of individual phospholipids content. As far as NSE administration caused a statistically significant decrease in free cholesterol level and had a considerable effect on normalization of individual phospholipids content of adipocytes, we can consider NSE as a prospective compound worthy more complex investigation of its action under the pathological conditions

Blood coagulation and aortic wall integrity in rats with obesity-induced insulin resistance

Obesity is an important factor in pathogenesis of disorders caused by chronic inflammation. Diet-induced obesity leads to dyslipidemia and insulin resistance (IR) that in turn provoke the development of type 2 diabetes and cardiovascular diseases. Thus, the aim of this work was to investigate the possible pro-atherogenic effects in the blood coagulation system and aortic wall of rats with obesity-induced IR. The experimental model was induced by a 6-month high-fat diet (HFD) in white rats. Blood samples were collected from 7 control and 14 obese IR rats. Prothrombin time (PT) and partial activated thromboplastin time (APTT) were performed by standard methods using Coagulometer Solar СТ 2410. Fibrinogen concentration in the blood plasma was determined by the modified spectrophotometric method. Levels of protein C (PC), prothrombin and factor X were measured using specific chromogenic substrates and activa­ting enzymes from snake venoms. Platelet aggregation was measured and their count determined using Aggregometer Solar AP2110. The aorta samples were stained by hematoxylin and eosin according to Ehrlich. Aortic wall thickness was measured using morphometric program Image J. Statistical analysis was performed using Mann-Whitney U Test. The haemostasis system was characterized by estimation of the levels of individual coagulation factors, anticoagulant system involvement and platelet reactivity. PT and APTT demonstrated that blood coagulation time strongly tended to decrease in obese IR rats in comparison to the control group. It was also detec­ted that 30% of studied obese IR rats had decreased factor X level, 40% had decreased level of prothrombin whereas fibrinogen concentration was slightly increased up to 3 mg/ml in 37% of obese IR rats. A prominent decrease of anticoagulant PC in blood plasma of obese rats was detected. Obese IR rats also had increased platelet count and higher rate of platelet aggregation in comparison to control animals. Histological analysis identified the disruption of aorta endothelium and tendency for the thickening of the aorta wall in the group with obesity-induced IR compared to the group of control rats. Changes of individual coagulation factors were assumed as the evidence of imbalance in the blood coagulation system. Increase of fibrinogen level, drop in PC concentration and pathological platelet reactivity were taken to corroborate the development of low-grade inflammation in obese IR rats. Instant generation of small amounts of thrombin in their blood plasma is expected. Since the aorta morphology assay detected the trend of its wall to thicken and the emergence of disruptions, we assumed there were initial stages of atherosclerosis and the danger of developing atherothrombosis. We detected an increase of blood coagulability and changes in aorta morphology in rats with obesity-induced IR which we assume indicate early development of atherosclerosis