牛磺酸对视网膜感光细胞光损伤及NFkB/caspase-1表达的影响  

EFFECTS OF TAURINE ON APOPTOSIS OF PHOTORECEPTORS AND NFκB/CASPASE-1 PATHWAY IN PHOTOCHEMICAL DAMAGE

作　　者：陈卡[1] 糜漫天[1] 余小平[1] 

机构地区：[1]第三军医大学营养与食品卫生学教研室,重庆400038

出　　处：《营养学报》2006年第4期296-299,共4页Acta Nutrimenta Sinica

基　　金：国家自然科学基金(No.30200228)

摘　　要：目的:观察牛磺酸对光化学损伤后感光细胞凋亡的影响,并探讨其防护机制。方法:70只SD大鼠随机分为对照组(control),牛磺酸组(taurine,Tau),分别喂饲标准饲料或添加4%Tau饲料15d后接受3000±200lx持续0、1、3、6、9、12、24h光照,用TUNEL法检测感光细胞凋亡并计算凋亡指数(apoptoticindex,AI),免疫印迹法测定caspase-1和核内p65蛋白表达水平,RT-PCR法检测IκBamRNA。结果:光照9h后Tau组出现凋亡细胞,且多个时相点该组AI值显著低于对照(P<0.05);短期光照(3h/6h)诱导p65核转位,Tau组核内p65量显著高于对照组(P<0.05),长时程光照后(12h/24h)对照组核内p65显著降低,Tau组仍有较高表达;光照1h后对照组IκBamRNA迅速升高,而Tau组在光照3、6h后升高较显著。视网膜caspase-1蛋白随光照时间延长表达增高,Tau组显著低于对照组对应时相点(P<0.05)。结论:牛磺酸抑制视网膜光化学损伤中感光细胞凋亡,可能与其维持NFκB激活状态进而下调caspase-1表达有关。Objective： To observe the effects of taurine （Tau） on photoreceptor apoptosis and investigate the mechanism. Method： Seventy rats were randomly divided into control group （Cont） and 4% taurine supplementation group （Tau）. The subjects were exposed to the cool white light （3000± 200 lx）for 0, 1, 3, 6, 9, 12 or 24 h. The apoptotic index （AI） of photoreceptor was evaluated by TUNEL method. Meanwhile, levels of p65 in nuclear and caspase-1 were determined by Western-blot analysis and Ir,.Ba mRNA was detected by RT-PCR. Results： After 9 h exposure, scattered TUNEL positive photoreceptors were found in Tau group, and each AI was lower than the corresponding control （P〈0.05）. Short-term exposure （3 h/6 h） induced p65 translocation into nuclear, and its level was relatively higher in Tau group （P〈0.05）, though p65 in nuclear in control group was decreased after prolonged exposure （12 h/24 h）, but remained higher in Tau group. Ir, Ba mRNA was elevated dramatically after lh exposure in control group while in Tau group the changes were marked after 3h. Caspase-1 in Tau group was lower than that in control （P〈0.05） . Conclusion： Taurine can partially prevent photoreceptors from apoptosis in photochemical damage, which may be correlated with keeping NFkB active and further down-regulation of caspase-1 expression.

关 键 词：牛磺酸 凋亡 NF K B P65 IKBa mRNA CASPASE-1 

分 类 号：R779.1[医药卫生—眼科]