Regulation of drugs on abnormal neovascularization of choroidal capillaries in diabetic rats

我们研究了脉络膜功能障碍与血管生成在糖尿病视网膜病变发病机制中的作用。(1)建立了链脲佐菌素(STZ)糖尿病大鼠早期和晚期脉络膜毛细血管体外培养系统。以外植体萌发的微血管数作为体外新生血管的指标。(2)无论有无胎牛血清(FBS)，糖尿病早期脉络膜毛细血管促进新生血管的程度均大于年龄匹配的正常幼鼠的毛细血管。(3)糖基化终末产物N(Epsilon)-(羧甲基)赖氨酸(CML)修饰的蛋白质促进脉络膜新生血管形成。抗CML的单抗6D12可抑制糖尿病对脉络膜新生血管的促进作用，但对正常毛细血管新生血管无影响。(4)糖尿病早期脉络膜毛细血管培养释放较高浓度的血管内皮细胞…与TIL对照组相比，L生长因子水平升高，肿瘤坏死因子-α和血小板衍生生长因子-BB水平有升高趋势。(5)粉防己碱及其相关化合物(KS-1-4)选择性地抑制糖尿病早期脉络膜新生血管形成，并通过血管内皮生长因子和血小板衍生生长因子-BB促进脉络膜新生血管的形成。(6)早期糖尿病不影响视网膜毛细血管的新生，但新生脉络膜毛细血管的形成抑制了共培养的视网膜新生血管。6D12恢复脉络膜毛细血管诱导的视网膜新生血管抑制作用。(7)脉络膜毛细血管促进了正常老年大鼠的新生血管生成，但对晚期糖尿病大鼠无明显影响。6D12抑制AGE诱导的脉络膜新生血管。晚期糖尿病患者的视网膜毛细血管促进新生血管形成，并通过共培养的脉络膜毛细血管增强新生血管形成。综上所述，CML修饰蛋白在脉络膜毛细血管内积聚，释放出血管内皮生长因子、可能的肿瘤坏死因子和血小板衍生生长因子，抑制糖尿病早期视网膜新生血管的形成。然而，CML修饰的蛋白在糖尿病晚期通过脉络膜毛细血管的血管生成活动增强了视网膜新生血管，从而诱导了糖尿病视网膜病变的发生。较少

We investigated roles of choroidal dysfunction with angiogenesis for induction of pathogenesis in diabetic retinopathy. (1) We developed in vitro culture system to study condition of choroidal capillaries in early and advanced stages of streptozotocin (STZ)-diabetic rats. The mumber of microvessels budded from explants was evaluated as index of in vitro neovascularization. (2) Choroidal capillaries in the early stage of diabetes facilitated neovascularization both with and without fetal bovine serum (FBS) to a greater extent than capillaries in age-matched normal young rats. (3) N(epsilon)-(carboxymthyl)lysine (CML)-modified proteins, one of advanced glycation end products facilitated choroidal neovascularization.6D12, a monoclonal antibody against CML, Suppressed the diabetic stale-facilitation of choroidal neovascularization but not neovascularization in normal capillaries. (4) Cultured choroidal capillaries in early stage-diabetes released higher concentration of vascular endothelia … More l growth factor (VEGF) and tended to increase tumor necrosis factor (TNT)-alpha and platelet-derived growth factor (PDGF)-BB, relative to tle Control. (5) Tetrandrine, a principal bis-benzylisoquinoline alkaloid isolated from."Stephania letrandrae S.Moore (root)" and its related synthetic compound (KS-1-4) selectively inhibited choroidal neovascularization ill early stage-diabetes and VEGF- and PDGF-BB-facilitaled choroidal neovascularization. (6) The early stagediabetes did not affect neovascularization of retinal capillaries but newly formed choroidal capillaries suppressed retinal neovascularization in co-culture. 6D12 restored choroidal capillary-induced suppression of the retinal neovascularization. (7) Choroidal capillaries facililaled neovascularizalion in normal older rat but did not change it in advanced stage-diabetes. 6D12 suppressed age-induced choroidal neovascularization. Retinal capillaries in advanced stage-diabetes facilitated neovascularization and were potentiated neovascularization by co-cultured choroidal capillaries. In conclusion, CML-modified proteins accumulated in choroidal capillary release VEGF, probably TNF and PDGF.and suppress the retinal neovascularization in early stage-diabetes. However, CML-modified proteins potentiated retinal neovascularization through the angiogenic activity of choroidal capillaries in the advanced stage-diabetes to induce pathogenesis of diabetic retinopathy. Less