Regulation of retinal inflammation by rhythmic expression of MiR-146a in diabetic retina.
Regulation of retinal inflammation by rhythmic expression of MiR-146a in diabetic retina.
复制标题
DOI：
10.1167/iovs.13-13076
复制
发表时间：
2014-05
影响因子：
4.4
通讯作者：
Qi Wang;Svetlana N. Bozack;Yuanqing Yan;M. Boulton;M. Grant;J. Busik
中科院分区：
文献类型：
--
作者：
Qi Wang;Svetlana N. Bozack;Yuanqing Yan;M. Boulton;M. Grant;J. Busik
目的慢性炎症和昼夜节律失调参与了糖尿病视网膜病变的发病机制。MicroRNAs(MiRNAs)可以调节炎症和生物钟机制。我们测试了一种假设，即糖尿病患者miR-146a表达的日节律改变有助于视网膜炎症。方法非糖尿病大鼠和STZ诱导的糖尿病大鼠处于12/12光/暗周期，每隔2小时处死一次，持续72小时。人视网膜内皮细胞与地塞米松同步化。实时荧光定量聚合酶链式反应和免疫印迹法检测MIR-146a、IL-1受体相关激酶1、IL-1β、血管内皮生长因子和细胞间黏附分子-1以及时钟基因的表达。为了调节miR-146a的表达水平，使用了模拟物和抑制剂。结果糖尿病抑制视网膜钟表机械负臂幅度(PER1)和正臂幅度(BMal1)。除了时钟基因，miR-146a及其靶基因IRAK1也表现出反相的每日振荡；然而，这些模式在糖尿病视网膜中消失了。这种节律模式的丧失与ICAM-1、IL-β和血管内皮生长因子表达的增加有关。人视网膜内皮细胞有较强的miR-146a表达，符合昼夜节律模式；然而，从糖尿病供体分离的HREC降低了miR-146a的幅度，但增加了IRAK1和ICAM-1的幅度。在HRECs中，miR-146a模拟物或抑制剂作用48h后，ICAM-1mRNA和蛋白表达水平分别下降1.6和1.7倍或1.5和1.6倍。结论糖尿病引起的miR-146a昼夜节律紊乱和miR-146a控制下的炎症途径可能与糖尿病视网膜病变的发生有关。
PURPOSE Chronic inflammation and dysregulation of circadian rhythmicity are involved in the pathogenesis of diabetic retinopathy. MicroRNAs (miRNAs) can regulate inflammation and circadian clock machinery. We tested the hypothesis that altered daily rhythm of miR-146a expression in diabetes contributes to retinal inflammation. METHODS Nondiabetic and STZ-induced diabetic rats kept in 12/12 light/dark cycle were killed every 2 hours over a 72-hour period. Human retinal endothelial cells (HRECs) were synchronized with dexamethasone. Expression of miR-146a, IL-1 receptor-associated kinase 1 (IRAK1), IL-1β, VEGF and ICAM-1, as well as clock genes was examined by real-time PCR and Western blot. To modulate expression levels of miR-146a, mimics and inhibitors were used. RESULTS Diabetes inhibited amplitude of negative arm (per1) and enhanced amplitude of the positive arm (bmal1) of clock machinery in retina. In addition to clock genes, miR-146a and its target gene IRAK1 also exhibited daily oscillations in antiphase; however, these patterns were lost in diabetic retina. This loss of rhythmic pattern was associated with an increase in ICAM-1, IL-β, and VEGF expression. Human retinal endothelial cells had robust miR-146a expression that followed circadian oscillation pattern; however, HRECs isolated from diabetic donors had reduced miR-146a amplitude but increased amplitude of IRAK1 and ICAM-1. In HRECs, miR-146a mimic or inhibitor caused 1.6- and 1.7-fold decrease or 1.5- and 1.6-fold increase, respectively, in mRNA and protein expression levels of ICAM-1 after 48 hours. CONCLUSIONS Diabetes-induced dysregulation of daily rhythms of miR-146a and inflammatory pathways under miR-146a control have potential implications for the development of diabetic retinopathy.