激活蛋白1(AP-1)在豚鼠进展性近视巩膜重塑中与Ⅰ型胶原的表达关系研究

Expression changes of activator protein 1 and its correlation with collagen Ⅰ in the sclera remodeling of progressive myopia in guinea pigs

目的研究近视眼巩膜重塑中激活蛋白-1(activator protein 1,AP-1)的动态表达变化以及与Ⅰ型胶原表达之间的关系。方法选取出生1周左右的三色豚鼠75只,随机抽取50只遮盖左眼建立形觉剥夺近视组(FDM组,50眼),其右眼作为自身对照组(50眼),其余25只豚鼠双眼均未做任何处理作为空白对照组(50眼),分别测量并记录空白对照组和FDM组豚鼠在遮盖前(0周)及遮盖后2周、4周、6周及遮盖4周去遮盖1周(4/-1周)时的双眼屈光度及眼轴长度。于上述5时间点分别处死豚鼠并制备巩膜组织切片,采用免疫组织化学染色法及逆转录PCR(RT-PCR)技术检测各组豚鼠巩膜中遮盖不同时间点AP-1和Ⅰ型胶原蛋白及mRNA的表达量并分析二者之间的关系。结果遮盖前空白对照组、自身对照组、FDM组的豚鼠屈光度均为远视,差异无统计学意义(P> 0. 05),FDM组由遮盖前(0周)时的远视眼(2. 09±0. 31) D到遮盖2周、4周、6周及4/-1周后逐渐变成近视眼[(-1. 23±0. 68) D、(-4. 17±0. 58) D、(-7. 07±0. 55) D、(-2. 67±0. 59) D],眼轴长度由遮盖0周(5. 93±0. 38) mm到遮盖2周、4周、6周及4/-1周后逐渐增加[(6. 62±0. 37) mm、(7. 30±0. 35) mm、(7. 99±0. 31) mm、(6. 97±0. 32) mm],与空白对照组、自身对照组比较,遮盖后各个时间点FDM组豚鼠近视屈光度明显升高,眼轴测量值明显增加,差异均有统计学意义(均为P <0. 05)。各组巩膜组织均有AP-1和Ⅰ型胶原蛋白与mRNA表达,遮盖前空白对照组、自身对照组与FDM组豚鼠巩膜组织中AP-1和Ⅰ型胶原蛋白及mRNA表达量的差异均无统计学意义(均为P> 0. 05),随着遮盖时间的延长,FDM组中AP-1和Ⅰ型胶原蛋白表达量均逐渐减弱(均为P <0. 05),AP-1和Ⅰ型胶原的mRNA表达也相应逐渐下调(均为P <0. 05),两者具有高度正相关性。结论在近视巩膜重塑过程中,AP-1可能作为转化生长因子-β1的下游信号转录因子参与调控Ⅰ型胶原的合成与降解。

Objective To investigate the dynamic changes of activator protein 1(AP-1)expression and analyze its relationship with collagenⅠexpression in myopic sclera collagen remodeling.Methods Totally 75 one-week-old guinea pigs were selected,fifty of them were extracted randomly to establish the form deprivation myopia(FDM)group by occluding their left eyes(FDM group,50 eyes),while their right eyes were sacrificed as the self-control group(50 eyes).Eyes of the 25 untreated guinea pigs were referred to as the normal control group(50 eyes).Binocular diopter and axial length of guinea pigs in the normal control group and FDM group were measured and recorded before occlusion and at the coverage of 2,4,6 weeks and consecutive occluding for 4 weeks followed by uncovering for 1 week(4/-1weeks),respectively.The guinea pigs were sacrificed at the above five time points and the scleral sections were prepared.The expression of AP-1 and collagenⅠin the sclera of guinea pigs covered at different time points was detected by immunohistochemistry and reverse transcription-polymerase chain reaction(RT-PCR)and the relationship between them was analyzed.Results The diopter of the guinea pigs in the normal control group,the self-control group and the FDM group were all hyperopic before occluding of eyes,and there was no significant differences between them(P >0.05).The diopter in the FDM group was gradually changed from hyperopia(2.09±0.31)D before occlusion to myopia after occlusion for 2,4,6 weeks and 4/-1 weeks[(-1.23±0.68)D,(-4.17±0.58)D,(-7.07±0.55)D,(-2.67±0.59)D],and the axial length was gradually increased correspondingly from(5.92±0.38)mm to[(6.62±0.37)mm,(7.30±0.35)mm,(7.99±0.31)mm and(6.97±0.32)mm].The diopter and axial length of guinea pigs in FDM group were increased significantly at each time point after occlusion compared with the normal control group and the self-control group.The differences were statistically significant(all P<0.05).The protein and mRNA expressions of AP-1 and collagenⅠwere both found in scleral tissues of all groups.The differences in the protein and mRNA expression of AP-1 and collagenⅠin the FDM group was not statistically significant before occlusion compared with the normal control group and the self-control group(all P >0.05).With the prolongation of occlusion time,the protein expressions of AP-1 and collagenⅠin the FDM group were gradually weakened(all P<0.05),the mRNA expression were also gradually down-regulated(all P<0.05),and there was positive correlation between them.Conclusion AP-1 is likely to be the downstream transcription factor of transforming growth factor-β1(TGF-β1),which can regulate the synthesis and degradation of collagenⅠin myopic sclera remodeling.