摘要背景 极低频电磁辐射产生的热效应与人类癌症的关系及其对眼表的影响已有较多研究.但眼球暴露于极低频电磁场(ELF-EMFs)下是否会导致巩膜的病理改变,从而影响近视的发生、发展目前鲜见报道. 目的 研究ELF-EMFs作用下人胚胎眼巩膜成纤维细胞(HFSFs)的分子病理改变及其在近视发生发展中的可能机制.方法 对HFSFs进行体外培养和传代,根据细胞是否暴露于50 Hz电磁场分为暴露组和对照组,应用实时定量聚合酶链反应( real-time PCR)法检测不同磁场强度(0、0.1、0.2、0.5、1.0 mT)、不同暴露时间(0、6、12、24、36、48 h)下HFSFs中Ⅰ型胶原蛋白(COL1A1)、基质金属蛋白酶2(MMP-2)的基因表达水平变化,同时应用CCK-8法检测两组HFSFs的细胞增生情况,并以细胞免疫荧光法对HFSFs中COL1A1和MMP-2蛋白的表达进行确认.结果 与对照组相比,暴露组在磁场强度0.2 mT下作用6h可见HFSFs中COL1A1 mRNA的表达下调,差异有统计学意义(对照组:0.099±0.008,暴露组:0.050±0.004;P=0.009),且表达量随着磁场强度的增加而减少；在磁场强度0.1 mT下暴露24 h,HFSFs细胞中的MMP-2 mRNA表达上调,差异有统计学意义(对照组:0.009±0.001,暴露组:0.018±0.003:P=0.038),并随着暴露时间的延长表达增强.磁场强度0.2 mT下暴露24 h,HFSFs细胞增牛的吸光度(A450)值明显下降,差异有统计学意义(P=0.009);免疫荧光分析也显示暴露组HFSFs细胞中COL1A1表达下调,MMP-2表达上调.结论 ELF-EMFs暴露可在一定范围内影响体外培养的HFSFs的增生及COL1 A1的合成,可能是诱导巩膜发生病理性重塑进而导致近视发生、发展的危险因素之一.

abstractsBackground The effects of extremely low frequency electromagnetic fields (ELF-EMFs) on public health have attracted wide attentions.The association of the thermal effect of ELF-EMFs with cancer and ocular tissue damage has been of concern.However,the pathological changes of scleral tissue after exposure to ELF-EMFs as well as the relationship between these changes and myopia are still poorly understood. Objective The present study was to investigate the molecular pathological changes of human fetal scleral fibroblasts (HFSFs) after exposure to ELF-EMFs in vitro and to explore the possible mechanism in the occurrence and development of myopia.Methods HFSFs were cultured and passaged and then exposed to 50 Hz electromagnetic fields,and HFSFs that did not receive the irradiation of ELF-EMFs were used as the control group.The expression of collagen type Ⅰ (COL1A1 ) mRNA and matrix metalloproteinase-2 (MMP-2) mRNA in cultured HFSFs were detected by real-time qualitative polymerase chain reaction (real-time PCR) under different magnetic field intensites (0,0.1,0.2,0.5,1.0 mT) and different exposure time (0,6,12,24,36,48 hours).Cell proliferation assay of HFSFs was detected by the cell counting kit 8 ( CCK8 ) assay.The expression levels of COL1 A1 and MMP-2 proteins in HFSFs were further confirmed by immunofluorescence staining. Results The expression of COL1A1 mRNA was significantly down-regulated under the exposure of 0.2 mT ELF-EMFs for 6 hours,in comparison with the control group;moreover,it decreased in parallel with the increased of flux density (0.099±0.008 vs.0.050±0.004) (P =0.009 ).The expression of MMP-2mRNA was up-regulated conspicuously after exposure to 0.1 mT ELF-EMFs for 24 hours,and it increased with exposure time in comparison with the control group ( 0.009 ±0.001 vs.0.018±0.003 ) ( P =0.038 ).Proliferation of HFSFs (A450) was inhibited following the exposure to 0.2 mT ELF-EMFs for 24 hours in comparison with the control group (P =0.009 ).The expression of COL1 A1 in the experimental group was decreased,compared with the control group,but the expression of MMP-2 was increased. Conclusions ELF-EMFs inhibit the proliferation of HFSFs and expression of COL1 A1 in HFSFs,which might be one of the reasons for the development of myopia.