Diabetic retinopathy is a serious complication of diabetes and is the leading cause of blindness in people with diabetes. At present, there are many views on the pathogenesis of diabetic retinopathy, including the changes of retinal microenvironment caused by high glucose, the formation of advanced glycation end products, oxidative stress injury, inflammatory reaction and angiogenesis factor. These mechanisms produce a common pathway that leads to retinal degeneration and microvascular injury in the retina. In recent years, cell regeneration therapy plays an increasingly important role in the process of repairing diseases. Different types of stem cells have neurological and vascular protection for the retina, but the focus of the target is different. It has been reported that stem cells can regulate the retinal microenvironment and protect the retinal nerve cells by paracrine production, and can also reduce immune damage through potential immunoregulation, and can also differentiate into damaged cells by regenerative function. Combined with the above characteristics, stem cells show the potential for the repair of diabetic retinopathy, this stem cell-based regenerative therapy for clinical application provides a pre-based evident. However, in the process of stem cell transplantation, homogeneity of stem cells, cell delivery, effective homing and transplantation to damaged tissue is still a problem of cell therapy.
ObjectiveTo observe the serum vascular endothelial growth factor (VEGF), apelin and heme oxygenase-1 (HO-1) levels in patients with type 2 diabetes mellitus (T2DM) and to explore their their relationship with diabetic retinopathy (DR).MethodsA total of 208 patients with T2DM and 50 healthy subjects (control group) from the Central Hospital of Western Hainan during January 2014 and December 2017 were selected in this study. Vision, slit lamp microscope, indirect ophthalmoscope and FFA examinations were performed on all the subjects. According to the results of the examinations combined with the DR clinical staging criteria, the patients were divided into non-DR (NDR) group, non-proliferative DR (NPDR) group, and proliferative DR (PDR) group, with 72, 76 and 60 patients in each, respectively. The clinical data of each group were recorded, and the levels of fasting blood glucose (FPG), HbA1c, total cholesterol (TC), three acylglycerol (TG), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), VEGF, apelin and HO-1 were detected in each group. The receiver operating characteristic curve (ROC) were used to analyze the value of VEGF, apelin and HO-1 in predicting the occurrence of PDR. Correlation analysis of serum VEGF, Apelin and HO-1 with clinical parameters in PDR patients by Pearson correlation analysis.ResultsThe level of VEGF (56.82±10.16 vs 91.74±22.83, 140.15±36.40, 195.28±42.26 pg/ml) and apelin (2.95±0.53 vs 4.68±0.74, 7.25±1.13, 10.16±1.35 ng/ml) in PDR group were significantly higher than those in NPDR, NDR and control groups (F=17.306, 21.814; P＜0.05). The level of HO-1 (50.37±10.14 vs 43.58±8.16, 30.25±6.28, 22.60±4.72 mmol/L) in PDR group was significantly lower than those in NPDR, NDR and control groups (F=15.827, P＜0.05). The ROC curve analysis showed that the best cut-off values of serum VEGF, apelin and HO-1 were 162.50 pg/ml, 8.30 ng/ml, 27.13 mmol/L, and the three combined to predict PDR of AUC (95%CI) was 0.906 (0.849−0.962), and their sensitivity (90.3%) and specificity (83%) were better. The correlation analysis showed that the VEGF, apelin and HO-1 of PDR patients were correlated with the course of diabetes (r=0.382, 0.416, −0.36; P＜0.05), FPG (r=0.438, 0.460, −0.397; P＜0.05) and HbAlc (r=0.375, 0.478, −0.405; P＜0.05), and the serum VEGF were correlated with apelin and HO-1 (r=0.793, −0.594; P＜0.01).ConclusionElevated serum VEGF and apelin levels and reduced HO-1 levels are associated with the progression of DR, and the three combination helps predict the occurrence of PDR.
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR). MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot. ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05). ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.
Objective To investigate if insulin can affect the expression of vascular endothelial growth factor (VEGF) in the retina of streptozotocin-induced diabetic rats. Methods A total of 60 male SpragueDawley rats were randomly divided into sodium citrate buffer control group (CIT-CON, n=30) and STZ-induced diabetic group (STZ-DM, n=30). At the 16th week, 24 rats from CIT-CON group at random were randomly divided to group A (sodium citrate buffer control group, n=12) and group B (sodium citrate buffer plus insulin group, n=12). The remaining 6 rats from as CIT-CON group served as negative control. At the same time, 24 rats from STZDM group at random were randomly divided to group C (STZinduced diabetic group, n=12) and group D (STZ-induced diabetic plus insulin group, n=12). The remaining 6 rats from STZ-DM group also served as negative control. 4 IU of insulin was injected subcutaneously to rats of group B and D. Immunohistochemistry, Western blot and Real-time polymerase chain reaction (RT-PCR) were used to measure the expression level of VEGF protein and mRNA respectively. RESULTS Insulin significantly increased the VEGF mRNA (7.71plusmn;0.25 vs 5.36plusmn;0.37, t test Plt;0.05) and protein expression (0.4925plusmn;0.0122 vs 0.4272plusmn;0.0110, t test Plt;0.05) in the retina of CITCON rats. However, in retina of STZDM rats, insulin had no effect on VEGF mRNA (8.92plusmn;0.27 vs 9.05plusmn;0.28, t test, Pgt;0.05) and protein expression (0.5152plusmn;0.0109 vs 0.5099plusmn;0.0100, t test Pgt;0.05). Conclusions Insulin had no effect on VEGF expression in the retina of STZ-DM rats.
ObjectiveTo investigate the role of apelin, glycosylated hemoglobin (HbA1c), cholesterol (TC), triglyceride (TG), High density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC) in the development and progress of diabetic retinopathy (DR). MethodsThe serum concentration of apelin, HbA1c, TC, TG, HDLC and LDLC were measured in 30 normal control subjects and 90 patients with type 2 diabetic mellitus, including 30 cases without DR (NDR), 30 with non-proliferative DR (NPDR), 30 with proliferative DR (PDR). These data were analyzed by SPSS for windows 13.0. ResultsThe serum concentration of apelin, HbA1c, TC, HDLC, LDLC were significantly higher in NDR, NPDR, PDR group than those in control group (F=403.06, 5.45, 4.27, 201.56, 4.90;P < 0.05). The serum concentration of TG has no significantly difference (F=2.19, P > 0.05). The serum concentration of apelin, HbA1c, TC, LDLC were significantly higher in NDR, NPDR, PDR group than those in control group (t=0.30, 0.58, 0.79;P < 0.05), the serum concentration of HDLC were significantly lower than those in control group(t=0.79, P < 0.01). There were significantly positive correlation between the progression of DR and the serum concentration of apelin, HbA1c, TC, LDLC(r=0.962, 0.562, 0.935;P < 0.05). There were significantly negative correlation between the progression of DR and the serum concentration of HDLC(r=-0.753, P < 0.01). There were correlation between apelin and HbA1c, LDLC and HDLC(r=0.956, 0.741, -0.691;P < 0.01). ConclusionOur data demonstrated that serum apelin levels increased significantly in patients with diabetic retinopathy, and are closely related to blood sugar, blood lipid metabolic abnormalities.
Objective To observe the genetic predisposition of complement C5 gene polymorphisms in proliferative diabetic retinopathy (PDR) in Chongqing Han population. Methods 400 type 2 diabetes (T2D) patients (case group) and 600 age- and sex-matched healthy controls (control group) were enrolled in this study. There were 8 PDR patients in case group. All the subjects were Han ethnic people. The immune-related representative SNP locus of C5 gene including rs2269067, rs7040033, rs7027797 were screened by linkage disequilibrium analysis. Locus rs1017119 was selected by TagSNP and was around the above three loci. Subjects′ peripheral venous blood was collected and DNA was extracted. Genotyping was examined by PCR-restriction fragment length polymorphism method. The level of C5 plasma protein was measured by enzyme-linked immunoabsorbent assay. Results The frequency of GG genotype of rs2269067 was significantly increased in PDR patients in cases group compared with controls (Pc=3.4×10-5, OR=1.87, 95%CI=1.43 - 2.44；P=3.1×10-6). There was no differences in frequency of G, CC and CG genotype of rs2269067 between two groups (P=1.4×10-4, 1.000, 1.0×10-6). There were no differences in frequency of G, CC, CG, GG genotype of rs7040033, rs1017119, and rs7027797 between two groups (P > 0.05). The production of C5 plasma protein was significantly increased in case group as compare with control group (P=0.0004). An increased production of C5 plasma protein was observed in rs2269067 GG genotype cases compared to CG or CC cases (P=0.003, 0.001). Conclusion C5 rs2269067 GG genotype may be associated with the PDR of T2D in Chongqing Han population.
Objective To observe the correlation between postmenopausal estrogen levels and diabetic retinopathy (DR) in women. Methods Thirty-nine menopause female patients with type 2 diabetes mellitus and 17 menopause subjects (control group) were enrolled in this study. Control subjects aged from 53 to 82 years, with the mean age of (69.80±8.32) years. Diabetes mellitus patients aged from 56 to 84 years, with the mean age of (70.50±8.27) years; diabetes duration ranged from 3 to 23 years, with the average course of diabetes (11.40±7.97) years. DR diagnosis was according to the results of fundus fluorescein angiography, and thus the 39 patients were divided into DR group (19 patients) and non-DR (NDR) group (20 patients). There was no significant difference in age and menopause duration between the three groups (t=0.347, 0.485;P＞0.05). There was significant difference in diabetes course (t=2.748,P＜0.05). Compared with NDR group, fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) were significantly increased (t=6.130, 5.322, 4.574, 2.426, 4.033), high density lipoprotein cholesterol (HDL-C) was significantly lower (t=3.917), the difference was statistically significant (P＜0.05). The level of estradiol (E2) was measured by radioimmunoassay. The differences of E2 levels between the three groups were compared. Logistic regression analysis was used to analyze the influencing factors of DR. Results The levels of E2 in control group, DR group and NDR group were (42.38±8.64), (21.49±9.81) and (32.72±10.51) pg/ml, respectively. The level of E2 in DR group was significantly lower than that in NDR group and control group (t=3.443, 10.110;P＜0.05). Logistic regression analysis showed that the duration of diabetes mellitus [coefficients =0.166, odds ratio (OR)=1.181,P= 0.016], FBG (coefficients=1.162,OR=4.014,P=0.001), TC (coefficients=3.212,OR=10.820,P=0.002), TG (coefficients=1.649,OR=5.203,P= 0.030) and LDL-C (coefficients=1.605,OR= 4.976,P=0.003) were the risk factors for DR; E2 (coefficients=−0.100,OR=0.904,P=0.004) and HDL-C (coefficients=−4.460,OR=0.012,P=0.002) were the protective factors for DR. Conclusion The estrogen level of postmenopausal women have a certain correlation with the development of DR, it may be one of the protective factor of DR.