State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
Diabetes Obes Metab. 2012 Jul;14(7):644-53. doi: 10.1111/j.1463-1326.2012.01584.x. Epub 2012 Mar 15.
KH902 is a fusion protein that can bind vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) through its binding ligand taken from the domains of VEGF receptor 1 and VEGF receptor 2 (VEGFR2). This study was to investigate the effects of intravitreal injection of KH902 on the retinas of streptozotocin-induced diabetic rats.
Two weeks after induction of diabetes, the left eyes of diabetic rats in each group received an intravitreal injection of phosphate-buffered saline (PBS), Avastin or KH902 solution, respectively. Four weeks after intravitreal injection, retinal electrophysiological function and the integrity of inner blood retinal barrier (iBRB) were measured by electroretinogram and Evans blue perfusion. The protein levels of VEGF signal pathway were assayed by western blot. The expression and distribution of claudin-5 and occludin were analysed by double immunofluorescent staining under confocal microscope. The expression of VEGFR2 and PlGF was measured by immunohistochemistry.
Four weeks after intravitreal injection, KH902-treated rats had better retinal electrophysiological function, less retinal vessel leakage and lower levels of VEGFR2, PI3K, AKT, p-AKT, p-ERK and p-SRC than PBS or Avastin-treated rats. The distribution of claudin-5 and occludin in the retinal vessels of diabetic rats treated by KH902 was smoother and more uniform than those of diabetic rats treated by PBS or Avastin. The expression of PlGF and VEGFR2 in KH902-treated rats was decreased compared with those in PBS or Avastin-treated rats.
KH902 could improve retinal electrophysiological function and inhibit the breakdown of iBRB by inhibiting the expression of VEGFR2, PlGF and PI3K, and the activation of SRC, AKT and ERK.
KH902 是一种融合蛋白，可通过其从血管内皮生长因子受体 1 和血管内皮生长因子受体 2（VEGFR2）的结合配体结合域中获取的结合配体来结合血管内皮生长因子（VEGF）和胎盘生长因子（PlGF）。本研究旨在探讨玻璃体内注射 KH902 对链脲佐菌素诱导的糖尿病大鼠视网膜的影响。
糖尿病诱导后 2 周，各组大鼠左眼分别玻璃体内注射磷酸盐缓冲液（PBS）、阿瓦斯汀或 KH902 溶液。玻璃体内注射后 4 周，通过视网膜电图和 Evans 蓝灌注测量视网膜电生理功能和内血视网膜屏障（iBRB）的完整性。通过 Western blot 测定 VEGF 信号通路的蛋白水平。通过共聚焦显微镜下的双重免疫荧光染色分析 Claudin-5 和 Occludin 的表达和分布。通过免疫组化测定 VEGFR2 和 PlGF 的表达。
玻璃体内注射 4 周后，与 PBS 或阿瓦斯汀治疗的大鼠相比，KH902 治疗的大鼠视网膜电生理功能更好，视网膜血管渗漏更少，VEGFR2、PI3K、AKT、p-AKT、p-ERK 和 p-SRC 水平更低。与 PBS 或阿瓦斯汀治疗的糖尿病大鼠相比，KH902 治疗的糖尿病大鼠视网膜血管中 Claudin-5 和 Occludin 的分布更平滑、更均匀。与 PBS 或阿瓦斯汀治疗的大鼠相比，KH902 治疗的大鼠 PlGF 和 VEGFR2 的表达减少。
KH902 通过抑制 VEGFR2、PlGF 和 PI3K 的表达以及 SRC、AKT 和 ERK 的激活，可改善视网膜电生理功能并抑制 iBRB 的破坏。
