不同显色指数LED照射对大鼠视网膜ROS/NLRP3的影响

Effect of light-emitting diode exposure with different color rendering indexes on retinal reactive oxygen species/NOD-like receptor family pyrin domain containing protein 3 of rats

目的探讨不同显色指数(CRI)的发光二极管(LED)对大鼠视网膜损伤的机制。方法将20只SD大鼠随机分为正常对照(NC)组(太阳光照明)、低CRI(CRI-L)组(蓝光照明)、中CRI(CRI-M)组(常规LED照明)和高CRI(CRI-H)组(全光谱LED照明),每组5只,每天光照12 h,连续4周。苏木精-伊红(HE)染色评估视网膜形态的变化;DHE染色检测视网膜组织中活性氧(ROS)的含量。通过实时定量聚合酶链反应(RT-qPCR)检测NLRP3、GSDMD和Caspase-1的mRNA表达,并通过免疫组织化学染色测定其蛋白质表达;使用光谱测量仪测量环境光谱。结果CRI-L组大鼠视网膜最薄,其次是CRI-M和CRI-H组。NC组、CRI-L组、CRI-M组及CRI-H组大鼠视网膜组织中ROS荧光强度分别为1.000±0.046、25.060±1.732、14.530±3.776、1.821±0.587。CRI-H组ROS表达水平低于CRI-L组与CRI-M组,差异均有统计学意义(均为P<0.05)。RT-qPCR结果显示,NC组、CRI-L组、CRI-M组及CRI-H组大鼠NLRP3的mRNA相对表达水平分别为1.004±0.005、4.004±0.716、2.027±0.303、0.741±0.069,Caspase-1的mRNA相对表达水平分别为1.010±0.006、4.337±0.345、2.268±0.058、0.713±0.021,GSDMD的mRNA相对表达水平分别为1.000±0.000、2.938±0.559、1.955±0.166、1.213±0.051。与NC组相比,CRI-L组及CRI-M组大鼠的NLRP3、Caspase-1和GSDMD相对表达水平均增加,差异均有统计学意义(均为P<0.05)。免疫组织化学染色结果显示,NC组、CRI-L组、CRI-M组及CRI-H组大鼠视网膜组织中NLRP3光密度值分别为0.3794±0.0022、0.4007±0.0114、0.3790±0.0069、0.3770±0.0075,Caspase-1光密度值分别为0.3672±0.0058、0.4426±0.0411、0.3824±0.0119、0.3806±0.0065,GSDMD光密度值分别为0.1595±0.0134、0.1675±0.0119、0.3976±0.0143、0.3772±0.0228。与NC组相比,CRI-L组大鼠NLRP3、Caspase-1光密度值均增加,CRI-M组和CRI-H组GSDMD光密度值均增加,差异均有统计学意义(均为P<0.05)。各组光谱比较显示,CRI-H组具有较宽的光谱覆盖范围和更接近自然光谱的分布。结论常规LED暴露可诱导大鼠视网膜厚度下降,视网膜组织中ROS表达增加,并上调NLRP3、Caspase-1和GSDMD的表达水平。高CRI的全光谱LED可通过优化其光谱分布通过ROS/NLRP3途径减轻细胞焦亡,具有更好的生物安全性。

Objective To investigate the mechanism of retinal injury in rats caused by light-emitting diodes(LEDs)with different color rendering indexes(CRIs).Methods Totally 20 Sprague-Dawley rats were randomly divided into normal control(NC)group(sunlight),low CRI(CRI-L)group(blue light),medium CRI(CRI-M)group(conventional LED),and high CRI(CRI-H)group(full-spectrum LED),with 5 rats in each group,exposed to light for 12 hours daily for 4 consecutive weeks.Hematoxylin&eosin staining was used to assess morphological changes in the retina.Dihydroethidium staining was employed to detect the levels of reactive oxygen species(ROS)in retinal tissues.The messenger ribonucleic acid(mRNA)expressions of NOD-like receptor family pyrin domain containing protein 3(NLRP3),Gasdermin D(GSDMD)and Caspase-1 were analyzed by real-time quantitative polymerase chain reaction(RT-qPCR),and their protein expressions were measured through immunohistochemical staining.Environmental light spectra were measured using a spectroradiometer.Results Rats in the CRI-L group showed the thinnest retina,followed by the CRI-M group and CRI-H group.The fluorescence intensity of ROS in the NC group,CRI-L group,CRI-M group and CRI-H group was 1.000±0.046,25.060±1.732,14.530±3.776 and 1.821±0.587,respectively.The ROS level in the CRI-H group was significantly lower than that in the CRI-L group and CRI-M group(both P<0.05).RT-qPCR showed that the relative mRNA expression of NLRP3 in the NC group,CRI-L group,CRI-M group and CRI-H group was 1.004±0.005,4.004±0.716,2.027±0.303 and 0.741±0.069,respectively;the relative mRNA expression of Caspase-1 was 1.010±0.006,4.337±0.345,2.268±0.058 and 0.713±0.021,respectively;the relative mRNA expression of GSDMD was 1.000±0.000,2.938±0.559,1.955±0.166 and 1.213±0.051,respectively.Compared with the NC group,the relative expressions of NLRP3,Caspase-1 and GSDMD in the CRI-L group and CRI-M group significantly increased(all P<0.05).The immunohistochemical staining results showed that the fluorescence intensity of NLRP3 in the retina of rats in the NC group,CRI-L group,CRI-M group and CRI-H group was 0.3794±0.0022,0.4007±0.0114,0.3790±0.0069 and 0.3770±0.0075,respectively;the fluorescence intensity of Caspase-1 was 0.3672±0.0058,0.4426±0.0411,0.3824±0.0119 and 0.3806±0.0065,respectively;the fluorescence intensity of GSDMD was 0.1595±0.0134,0.1675±0.0119,0.3976±0.0143 and 0.3772±0.0228,respectively.Compared with the NC group,rats in the CRI-L group showed increased fluorescence intensity of NLRP3 and Caspase-1,and rats in the CRI-M and CRI-H showed increased fluorescence intensity of GSDMD(all P<0.05).The spectral comparison revealed that the CRI-H group had a broader spectral coverage and a distribution closer to natural light spectra.Conclusion Conventional LED exposure can induce a decrease in retinal thickness,upregulate the ROS expression in retinal tissues,and increase the expression levels of NLRP3,Caspase-1 and GSDMD.High CRI full-spectrum LEDs can mitigate pyroptosis through the ROS/NLRP3 pathway by optimizing their spectral distribution,offering better biosafety.