Shi Fan-Jun, Xie Hai, Zhang Chao-Yang, Qin Hai-Feng, Zeng Xin-Wei, Lou Hui, Zhang Lei, Xu Guo-Tong, Zhang Jing-Fa, Xu Guo-Xu
Department of Ophthalmology, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu Province, China.
Department of Ophthalmology, Changzhou Laser Hospital, Changzhou 213000, Jiangsu Province, China.
Int J Ophthalmol. 2021 Feb 18;14(2):200-208. doi: 10.18240/ijo.2021.02.04. eCollection 2021.
To investigate the changes of Iba-1 and other potential markers for microglia activation in experimental diabetic retinopathy (DR).
Male Sprague-Dawley rats were rendered diabetes intraperitoneal injection of streptozotocin. The retinas were harvested at 1 to 24wk after diabetes onset. Hypoxia-treated mouse microglial cell line (BV2 cells) was employed as the model to mimic diabetic condition. The expressions of Iba-1, CD11b, ICAM-1 as well as the inflammatory factors were examined with real-time polymerase chain reaction, Western blot and immunofluorescence both and .
Compared with age-matched normal control, the number of microglia (Iba-1 positive immunostaining) in diabetic rat retinas was increased from 1 to 24wk of diabetes, which was most obvious at 12wk of diabetes. Iba-1 protein expression detected by Western blot was increased slightly in diabetic rat retinas compared with that in age-matched normal control; however, there was statistically significant between two groups only at 2wk after diabetes onset. The mRNA expression of Iba-1 was decreased significantly at 2 and 4wk of diabetic rat retinas, and remained unchanged at 8 and 12wk of diabetes. In BV2 cells, there was no significant change for the Iba-1 protein expression between normoxia and hypoxia groups; however, its mRNA level was decreased significantly under hypoxia. To further characterize microglial activation, F4/80, CD11b and inflammatory factors were detected both and Compared with normal control, the expressions of F4/80 and CD11b as well as the inflammatory factors, such as ICAM-1, iNOS, COX2, IL-1β and IL-6, were increased significantly both and .
Iba-1 protein expression might not be a sensitive marker to evaluate the activation of microglia in experimental DR. However, Iba-1 immunostaining, in combination with other markers like CD11b and ICAM-1, could be well reflect the activation of microglia. Thus, it is of great importance to explore other potential marker to evaluate the activation of microglia.
研究实验性糖尿病视网膜病变（DR）中Iba-1及其他小胶质细胞活化潜在标志物的变化。
雄性Sprague-Dawley大鼠通过腹腔注射链脲佐菌素诱导糖尿病。在糖尿病发病后1至24周采集视网膜。采用缺氧处理的小鼠小胶质细胞系（BV2细胞）作为模拟糖尿病状态的模型。通过实时聚合酶链反应、蛋白质免疫印迹法和免疫荧光法检测Iba-1、CD11b、ICAM-1以及炎症因子的表达。
与年龄匹配的正常对照组相比，糖尿病大鼠视网膜中小胶质细胞（Iba-1阳性免疫染色）数量在糖尿病发病后1至24周增加，在糖尿病发病12周时最为明显。蛋白质免疫印迹法检测显示，糖尿病大鼠视网膜中Iba-1蛋白表达与年龄匹配的正常对照组相比略有增加；然而，仅在糖尿病发病后2周两组之间存在统计学差异。糖尿病大鼠视网膜在2周和4周时Iba-1的mRNA表达显著降低，在糖尿病发病8周和12周时保持不变。在BV2细胞中，常氧组和缺氧组之间Iba-1蛋白表达无显著变化；然而，在缺氧条件下其mRNA水平显著降低。为进一步表征小胶质细胞活化，同时检测F4/80、CD11b和炎症因子。与正常对照组相比，F4/80和CD11b以及炎症因子如ICAM-1、诱导型一氧化氮合酶、环氧化酶2、白细胞介素-1β和白细胞介素-6的表达均显著增加。
Iba-1蛋白表达可能不是评估实验性DR中小胶质细胞活化的敏感标志物。然而，Iba-1免疫染色与CD11b和ICAM-
