ObjectiveTo observe the expression of Toll-like receptor 4 (TLR4) and inflammatory cytokines, leucocytic density and permeability in retina of diabetic rat. MethodsA total of 106 Brown Norway rats were randomly divided into experimental group and control group with 53 rats in each group. Diabetic model was established in experimental group by intraperitoneal injection of streptozotocin, and control rats received intraperitoneal injection of an equal volume of citric acid-sodium citrate buffer. Four weeks later, the retinas were collected for further analysis. TLR4 RNA and protein expression were measured by quantitative polymerase chain reaction and Western blot. Inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), monocyte chemo-attractant protein-1 (MCP-1), were measured by enzyme-linked immunosorbent assay in rat retina homogenate. Leukocyte density in the retina was measured by acridine orange fundus angiography. The retinal permeability was evaluated by Evans blue (EB) staining. ResultsTLR4 expression was significantly increased in diabetic rats of experimental group compared with non-diabetic rats of control group (F=1.606, 0.789; P < 0.05). Inflammatory cytokines (TNF-α, IL-1β and MCP-1) were significantly increased in retina of diabetic rats of experimental group versus non-diabetic rat of control group (F=24.622, 5.758, 4.829; P < 0.05). The retinal leukocyte density was (6.2±0.5)×10-5, (2.2±0.3)×10-5 cells/pixel2 in experimental and control group respectively, the difference was statistically significant (F=2.025, P < 0.05). The amount of retinal EB leakage was (23.41±4.47), (13.22±3.59) ng/mg in experimental and control group respectively, the difference was statistically significant (F=21.08, P < 0.05). ConclusionTLR4 and inflammatory cytokines expression, leucocytic density and permeability increased significantly in retina of diabetic rat.
ObjectiveTo observe the expression of inflammatory cytokines in diabetic rats received posterior sub-Tenon capsule injection of triamcinolone acetonide (TA) and pan-retinal photocoagulation. MethodsA total of 48 Brown Norway rats received intraperitoneal injection of streptozotocin to establish the diabetic model. Diabetic rats were randomly divided into experimental group (20 rats), control group (20 rats) and blank group (8 rats). 50 μl TA or saline was injected into the posterior sub-Tenon capsule immediately after the photocoagulation in the experimental group and the control group, respectively. The blank group received no treatment. The mRNA and protein expression level of retinal vascular endothelial growth factor (VEGF), interleukin-6 (IL-6) and tumor necrosis fator-α (TNF-α) were measured by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) at 1, 3, 7 days after laser photocoagulation. ResultsThe mRNA and protein expression of VEGF, IL-6, TNF-α of the experimental group and control group were significantly higher than the blank group, the difference was statistically significant (P < 0.05). The mRNA and protein expression of VEGF, IL-6 and TNF-α of the experimental group were significantly lower than that of the control group. On day 1 after laser photocoagulation, the mRNA expression of VEGF was not statistically significant in the experimental group and control group (P > 0.05), the mRNA and protein expression of VEGF, IL-6, TNF-α of the two groups were statistically significant in the remaining observing time (P < 0.05). ConclusionPosterior sub-Tenon capsule injection of TA can effectively reduce retinal photocoagulation induced VEGF, IL-6, TNF-α expression.