Aquaporin 4 knockdown exacerbates streptozotocin-induced diabetic retinopathy through aggravating inflammatory response
Aquaporin 4 knockdown exacerbates streptozotocin-induced diabetic retinopathy through aggravating inflammatory response
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DOI：
10.1016/j.exer.2012.02.013
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发表时间：
2012-05-01
影响因子：
3.4
通讯作者：
Li, Wen-Jie
中科院分区：
文献类型：
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作者：
Cui, Bei;Sun, Jin-Hua;Li, Wen-Jie
糖尿病视网膜病变是视力下降和获得性失明的主要原因。已知糖尿病会改变视网膜水选择通道水通道蛋白4 （AQP4）的表达量。然而，AQP4在糖尿病视网膜病变中的功能和影响尚不清楚。本研究采用Sprague-Dawley大鼠腹腔注射链脲佐菌素诱导糖尿病。2周后，玻璃体内注射AQP4 shRNA (r)慢病毒颗粒或阴性慢病毒颗粒给眼。通过定量逆转录聚合酶链反应（qRT-PCR）和Western blotting分析证实基因传递。8周后，用埃文斯蓝染料测定BRB分解。获得视网膜切片图像并确定视网膜的厚度。采用吖啶橙白细胞荧光法测定视网膜白斑。采用qRT-PCR法检测大鼠IL-1 β、IL-6、细胞间粘附分子1 （ICAM-1）、胶质纤维酸性蛋白（GFAP）、血管内皮生长因子（VEGF） mRNA水平。将AQP4 shRNA (r)慢病毒颗粒或阴性慢病毒颗粒转染rMC-1细胞，研究其对高糖诱导炎症的影响。与IL-1 β或IL-6孵育，检测其对rMC-1细胞中AQP4表达的影响。在目前的工作中，我们发现AQP4在糖尿病大鼠视网膜中的表达增强。AQP4敲低导致糖尿病大鼠视网膜血管通透性、视网膜厚度、促炎因子表达、VEGF和GFAP表达增加等视网膜病变加重。AQP4敲低可增强高糖诱导的rMC-1细胞中促炎细胞因子的表达。此外，AQP4敲低可增强rMC-1细胞向培养基中释放IL-6和VEGF。此外，我们发现与IL-1 β或IL-6孵育可抑制rMC-1细胞中AQP4的表达。这些结果表明，链脲佐菌素诱导糖尿病导致AQP4表达代偿性升高，AQP4下调通过加重炎症反应加重糖尿病视网膜病变，至少在一定程度上是这样。因此，通过AQP4调节视网膜功能可能会减轻糖尿病视网膜病变，为糖尿病视网膜病变的治疗提供了一种有前景的治疗策略。(c) 2012年Elsevier Ltd.出版。
Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Diabetes is known to alter the amount of retinal expression of the water-selective channels aquaporin 4 (AQP4). However, the function and impact of AQP4 in diabetic retinopathy is not well understood. In the present work, diabetes was induced by intraperitoneal injection of streptozotocin in Sprague-Dawley rats. Two weeks later, AQP4 shRNA (r) lentiviral particles or negative lentiviral particles were delivered by intravitreal injection to the eyes. Gene delivery was confirmed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blotting analysis. Eight weeks later, BRB breakdown was measured using Evans blue dye. Images of retinal sections were obtained and the thicknesses of the retinas were determined. Retinal leukostasis measurement was performed using acridine orange leukocyte fluorography. The mRNA levels of IL-1 beta, IL-6, intercellular adhesion molecule 1 (ICAM-1), glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined using qRT-PCR method. AQP4 shRNA (r) lentiviral particles or negative lentiviral particles were transfected into rMC-1 cells to investigate its effect on inflammation induced by high glucose. Incubation with IL-1 beta or IL-6 was performed to test their effect on AQP4 expression in rMC-1 cells. In the current work, it was found that AQP4 expression was enhanced in the retina of diabetic rats. AQP4 knockdown led to exacerbation of retinopathy including enhancing retinal vascular permeability, retinal thickness, pro-inflammatory factors expression, and VEGF and GFAP expression in retinas of diabetic rats. AQP4 knockdown enhanced the expression of pro-inflammatory cytokines induced by high glucose in rMC-1 cells. In addition, AQP4 knockdown enhanced the release of IL-6 and VEGF from rMC-1 cells into the medium. Moreover, it was found that incubation with IL-1 beta or IL-6 suppressed AQP4 expression in rMC-1 cells. These results suggested that streptozotocin injection induced diabetes resulted in compensatory increases of AQP4 expression, and downregulation of AQP4 exacerbated diabetic retinopathy through aggravating inflammatory response, at last in part. Therefore, regulation of retinal function by AQP4 may attenuate diabetic retinopathy, offering a promising therapeutic strategy for diabetic retinopathy. (c) 2012 Published by Elsevier Ltd.