血管内皮生长抑制因子在糖尿病视网膜病变大鼠中的表达

目的 观察血管内皮生长抑制因子（VEGI）及其相关因子在糖尿病（DM）大鼠外周血、玻璃体液及视网膜组织中的表达，探讨VEGI在糖尿病视网膜病变（DR）发病机制中的作用。方法 70只6周龄雄性Wistar大鼠，随机分为空白对照组（10只），DM 1、3、6个月组（各20只）。DM大鼠模型建立后，分别于1、3、6个月时取大鼠外周血、玻璃体液、全眼球。酶联免疫吸附测定法检测肿瘤坏死因子样配体1/血管内皮生长抑制因子251（TL1A/VEGI 251）、血管内皮生长因子（VEGF）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）在血清及玻璃体液浓度，石蜡切片免疫组织化学法检测各因子在视网膜组织中的表达，苏木素 伊红（HE）染色评价各组大鼠DR进程。比较空白对照组和DM实验组间大鼠血清、玻璃体液及视网膜组织中TL1A、VEGF、TNF-α、IL-1β的表达差异。结果 分析采用单因素方差分析、独立样本t检验和最小显著差法检验。结果 空白对照组、DM 1、3、6个月组大鼠血清TL1A浓度分别为（92.09±2.05）、（118.36±8.30）、（85.90±7.51）、（78.90±4.88） ng/L，组间血清TL1A浓度比较，差异有统计学意义（F=77.405，P＜0.05）。从空白对照组到DM 1、3、6个月组，大鼠血清TNF-α、IL-1β浓度均呈升高趋势，4组间血清TNF-α、IL-1β浓度比较，差异有统计学意义（F=3.508、15.416，P＜0.05）。VEGF浓度在DM 1个月时升高，DM 3个月时下降，DM 6个月时再次升高，但4组间VEGF浓度比较，差异无统计学意义（F=1.242，P＞0.05）。各组大鼠玻璃体液TL1A浓度分别为（91.50±8.18）、（67.03±6.74）、（47.44±4.92）、（46.01±4.62） ng/L，组间TL1A浓度比较，差异有统计学意义（F=114.777，P＜0.05）。从空白对照组到DM 1、3、6个月组，大鼠玻璃体液VEGF、TNF-α、IL-1β浓度均呈升高趋势，4组间VEGF、TNF-α、IL-1β比较，差异有统计学意义（F=8.816、4.392、3.635，P＜0.05）。免疫组织化学检测结果显示，DM 1、3个月组大鼠视网膜TL1A表达吸光度［A，旧称光密度（OD）］值均较空白对照组降低（t=6.851、6.066，P＜0.05），但DM 6个月组与空白对照组的TL1A表达A值比较，差异无统计学意义（t=1.401，P＞0.05）；DM各组大鼠视网膜VEGF和TNF-α表达A值均较空白对照组显著升高（t_VEGF=-4.709、-16.406、-9.228，P＜0.05；t _TNF-α=-4.703、-6.583、-17.762，P＜0.05）；DM 1、6个月组大鼠视网膜IL-1β表达A值均较空白对照组显著升高（t=-4.108、-3.495，P＜0.05），但DM 3个月组与空白对照组IL-1β表达A值比较，差异无统计学意义（t=-0.997，P＞0.05）。HE染色结果显示，空白对照组与DM 1个月组大鼠视网膜组织结构基本正常；DM 3个月组大鼠视网膜组织水肿，细胞排列紊乱；DM 6个月组大鼠视网膜组织明显水肿，神经节细胞核染色加深，内丛状层可见大量新生血管，内核层细胞排列紊乱、水肿，可见大量脂肪空泡，视网膜各层结构不清晰。结论 VEGI可能通过与VEGF、TNF-α、IL-1β等因子的相互作用参与DR的发生发展过程。

Expression of vascular endothelial growth inhibitor in diabetic retinopathy rats

Objective To observe the expression of vascular endothelial growth inhibitor (VEGI,TL1A), vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in diabetes rats′ serum, vitreous and retina, and discuss the role of VEGI in the pathogenesis of diabetic retinopathy (DR). Methods A total of p70 adult male Wistar rats were randomly divided into 4 groups, the control group (10 rats), the diabetes mellitus (DM) 1 month group (20 rats), the DM 3 month group (20 rats) and the DM 6 month group (20 rats). Cytokines of serum and vitreous were determined by enzyme-linked immunosorbent assay (ELISA), and the concentrations of the cytokines in the retina were determined by immunohistochemistry on paraffin retinal sections. Hematoxylin-eosin (HE) staining of retina was used to estimate the pathological change of DR. The results were analyzed by one-way analysis of variances, independent samplest-test and LSD test. Results The serum TL1A levels of the control group, the DM 1 month group, the DM 3 month group and the DM 6 month group rats were (92.09±2.05), (118.36±8.30), (85.90±7.51) and (78.90±4.88) ng/L respectively, the level of TL1A in serum of the DM 1 month group, the DM 3 month group and the DM 6 month group were significantly lower than that of the control group (F=77.405, P＜0.05). The concentration of serum TNF-α and IL-1β increased after DM model was established (F=3.508, 15.416;P＜0.05); the VEGF level in serum showed no difference between the groups (F=1.242, P＞0.05). The vitreous TL1A levels of the control group, the DM 1 month group, the DM 3 month group and the DM 6 month group were (91.50±8.18), (67.03±6.74), (47.44±4.92) and (46.01±4.62) ng/L respectively, every DM groups showed significant difference with the control group (F=114.777,P＜0.05); VEGF level in vitreous increased from 1 month after DM model was established (F=8.816,P＜0.05); TNF-α and IL-1β level in vitreous also showed an upward tendency (F=4.392,3.635;P＜0.05). Paraffin section immunohistochemistry showed that the absorbance (also called optical density) of TL1A of the DM 1 month group and the DM 3 month group were significantly lower than that of the control group (t=6.851, 6.066;P＜0.05), but the DM 6 month group showed no difference with the control group (t=1.401,P＞0.05); the level of VEGF and TNF-α in DM groups were higher than that of the control group (t _VEGF=-4.709, -16.406, -9.228;t _TNF-α=-4.703, -6.583, -17.762;P＜0.05); the level of IL-1β were significantly higher in the DM 1 month group and the DM 6 month group (t=-4.108, -3.495;P＞0.05); but the DM 3 month showed no difference with the control group (t=-0.997,P＞0.05). HE staining of retina showed that the retina of the control group and the DM 1 month group had normal retinal structures, the DM 3 month group had retinal edema and disorganization, the DM 6 month group had severe retinal edema, deep stain of ganglion cells, and more neovascularization in inner plexiform layer. Conclusion VEGI is involved in the pathogenesis of DR, and it might interacts with VEGF, TNF-α and IL-1β to affect the development of DR