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.
ObjectiveTo observe the changes in open probability and protein expression of large conductance Ca2+-activated K+ (BK) channel in retinal vascular smooth muscle cells (RVSMCs) of diabetic rats. MethodsStreptozotocin (STZ)-induced rat diabetic animal model was established by STZ injection intraperitoneally.RVSMCs were isolated by enzyme digestion. The BK currents in control and diabetic groups were recorded by patch clamp technique in single channel configuration. BK channel protein expression in control and diabetic group were measured by Western blot. ResultsCompared with control group, the NP0 of BK channels in diabetic group were significantly increased (t=4.260, P < 0.05). Compared with control group, there was no significant difference inα-subunit protein expression in diabetic group in RVSMCs (t=10.126, P > 0.05); however, β1-subunit protein expression was remarkably increased in diabetic group (t=5.146, P < 0.05). ConclusionThe NP0 of BK channels andβ1-subunit protein expression are increased in RVSMCs of diabetic rats.
Objective To investigate the prevalence rate and risk factors of diabetic retinopathy (DR) in residents aged 50 and above in Binhu Area, Wuxi City. Methods Stratified cluster random sampling method was used to investigate the prevalence of DR of residents aged 50 and above from January to December 2010. Detailed medical history, general examination, visual acuity, slit lamp microscope, direct ophthalmoscopy and blood sample testing were conducted for all selected subjects. DR diagnostic criteria refer to the 2002 International DR classification criteria. Unilateral or bilateral DR was both considered as DR patients.χ2 test was used for statistical analysis of risk factors, and independent risk factors were screened by SPSS 17.0 software. Results A total of 6150 residents underwent the examination with a participating rate of 91.5%. Seven hundred and three residents were diagnosed as with diabetes, in which 40 were unable to record the fundus condition due to opaque refractive media. Among the rest 663 diabetic patients, 36 (5.4%) were DR patients. There were 34 non-proliferative DR (5.1%) and two proliferative DR (0.3%). The duration of diabetes and fasting blood-glucose were the independent risk factor of DR (r=0.008, 0.009; P＜0.05). Conclusions The prevalence rate of DR is low in the residents aged 50 and above in Binhu Area, Wuxi City. The duration of diabetes and fasting blood-glucose level were confirmed as the independent risk factor of DR.
Objective To investigate the causes of blindness and low vision of the people over 50 years old in Binhu Area of Wuxi City. Methods Cluster sampling was used in randomly selected individuals over 50 years old in 28 villages. The oculopathy related to blindness and low vision of the people over 50 years old were analyzed. The vision acuity lt;0.05 was defined as blindness, while 0.05-0.3 was defined as low vision. SPSS 17.0 software was used to analyze the data. Results Totally 6150 individuals were examined. The bilateral blindness and low vision was found in 47 and 84 individuals, unilateral blindness and low vision was found in 201 and 214 individuals. Among 201 unilateral blindness individuals, there were 55 individuals have low vision in the other eye. In the 295 blind eyes, there are 116 eyes (39.32%) with cataract, 31 eyes (10.51%) with high myopia macular degeneration, and 28 (9.49%) eyes with atrophy eyeballs. In the 437 low vision eyes, there are 223 eyes (51.03%) with cataract, 41 (9.38%) eyes with high myopia macular degeneration, and 41 (9.38%) eyes with age-related macular degeneration. Conclusion Cataract is the first cause leading to blindness and low vision, followed by age-related macular degeneration, high myopia macular degeneration and atrophy eyeballs.