白细胞介素-1β对大鼠视网膜Muller细胞磷酸化的信号转导及转录活化因子3表达的影响

Interleukin-1β promotes the expression of pSTAT3 in rat retinal Miiller cells

目的观察不同浓度白细胞介素-1β（IL-1β）对大鼠视网膜Muller细胞磷酸化的信号转导及转录活化因子3（pSTAT3）表达的影响。方法将体外培养的Sprague—Dawley（SD）大鼠Muller细胞分别以0．0、0．1、1．0、5．0、10．0ng／ml浓度的IL-1β刺激24h后，免疫荧光法和蛋白质印迹（Western botting）检测细胞内pSTAT3的表达改变。SD大鼠32只，随机分为对照组、100、500、1000ng／ml组，每组均为8只大鼠。分别将磷酸缓冲液（PBS）配制的浓度分别为100、500、1000ng／ml的IL-1β注人大鼠的左眼玻璃体腔中，对照组大鼠左眼玻璃体腔注射相同容积的PBS，24h后采用同样方法检测pSTAT3在视网膜的表达情况。结果免疫荧光法和Westernbotting检测结果显示，IL-1β刺激24h后，IL-1β浓度为0．0ng／ml时，pSTAT3在细胞核内有极少量表达，当浓度达到1．0ng／ml后，pSTAT3在细胞核内的表达随浓度增加而升高，差异有统计学意义（F=46．64，43．78；P〈0．01）。对照组大鼠视网膜内无明显pSTAT3的表达，当浓度达到100．0ng／ml后，pSTAT3在视网膜内的表达随浓度增加而升高，差异有统计学意义（F=73．53，43．70；P〈0．01）；pSTAT3主要表达于内核层和神经节细胞层。双荧光标记显示，对照组大鼠视网膜内无pSTAT3表达，胶质纤维酸性蛋白（GFAP）主要表达于神经节细胞层，并向视网膜色素上皮层呈丝状放射；从100ng／ml IL-1β刺激24h后起，内核层就出现颗粒状GFAP和pSTAT3的双标染色。结论IL-1β可以上调Muller细胞pSTAT3的表达，这可能是Muller细胞发生反应性胶质活化的通路之一。

Objective To observe the influence of interleukin-1β （IL-1β） on the expression of phosphorylated signal transducers and activators of transcription 3 （pSTAT 3） in rat retinal Muller cells. Methods For in vitro study cultured Mtiller cells were treated with IL-1β of different concentrations （0, 0.1, 1, 5 and 10 ng/ml） for 24 hours. For in vivo study, 32 Sprague-Dawley（SD）rats were divided into 4 groups randomly （control group, 100,500 and 1000 ng/ml group） with 8 rats in each group. After 24 hours of injection with phosphate buffered solution （PBS）, or 100, 500, 1000 ng/ml IL-D into the vitreous cavities of the above rats, retinas were harvested. The expressions of pSTAT3 in cultured Muller cells or treated retinas were evaluated by indirect immunofluorescence and western blotting. Results After 24 hours of incubation without IL-1β, pSTAT3 has little expression in cultured Muller ceils, but was up-regulated by 1 ng/ml or higher IL-1β in a dosage-dependent manner （F： 46.64, 43.78; P〈0.01）. pSTAT3 was not expressed in adult rat retina, but was up-regulated by vitreous injection of 100 ng/ml or higher IL-1β in a dosage-dependent manner （F= 73.53, 43.70; P〈0.01）. pSTAT3 expressed mainly in inner nuclear layer and ganglion cell layer. Double-labeling showed that there was no co-staining of pSTAT3 and glial fibrillary acidic protein （GFAP） in retina of control group, but there were many co-stained Muller cells in retinas treated with IL-1β. Conclusions Expression of pSTAT3 in Muller cells could be activated by IL-1β which may represent one pathway link to reactive gliosis.