豚鼠形觉剥夺性近视视网膜早基因c-fos的动态表达

目的建立豚鼠形觉剥夺性近视(form-deprivationmyopia,FDM)动物模型,并对豚鼠形觉剥夺性近视形成及恢复过程中视网膜早基因c-fos的动态变化进行观察,研究豚鼠FDM中视网膜信号转导及抑制近视的可能分子机制。方法3周三色豚鼠40只,随机均分为4组:遮盖前组、单眼遮盖1周组、单眼遮盖2周组及去遮盖组。对各组进行视网膜检影和A超测眼轴,分别运用免疫组化和RT-PCR观察各组视网膜c-fos蛋白及mRNA的表达和变化。结果遮盖2周后,遮盖眼较对照眼呈高度相对近视(-8.8 D),视网膜c-fos表达明显下调,双眼屈光度、眼轴和视网膜c-fos的表达差异均有显著性(P<0.05);遮盖2周后,去遮盖1周,去遮盖眼较对照眼呈中度相对近视(-5.9 D),但去遮盖前后屈光度及眼轴差异无显著性(P>0.05),去遮盖眼较对照眼视网膜c-fos的表达明显上调,差异有非常显著性(P<0.01)。结论形觉剥夺能成功诱导豚鼠近视的发生及发展,并抑制视网膜c-fos的表达,而去除形觉剥夺可抑制近视的发展,并诱导视网膜c-fos的表达上调,证明c-fos的表达规律不仅反映外界视觉环境对眼的刺激,并与近视发展规律呈负相关,可能参与视网膜的信号转导和近视的抑制机制。

Changes of c-fos expression induced by form deprivation myopia in guinea pigs

Objective To investigate expression of immediate-early gene c-fos in retina and factors involved in regulation of ocular growth in eyes treated by form deprivation.Methods Forty guinea pigs of three weeks old were randomly assigned to four groups: group 1 underwent monocular form deprivation(MFD) by a opaque headgear for 1 week;group 2 was treated with similar deprivation for 2 weeks;group 3 recovered for 1 week from 2-week deprivation and group 4 free of form deprivation as a normal control.Development in both refraction and axial length of the eye was measured before and during the experimental period.Expression of immediate-early gene c-fos was quantified by immunohistochemistry and RT-PCR.Results The MFD eyes showed significant myopia compared to the contralateral eyes and controlled groups with an increasing axial length and a down-regulated expression of immediate-early gene c-fos(P<0.05).The recovered group had the refractive back to moderate myopia.And the expression of immediate-early gene cfos increased significantly in recovered group(P<0.01).Conclusion Form deprivation myopia can be induced in guinea pigs.The level of expression in immediate-early gene c-fos was significantly correlated with the myopic development.Immediate-early gene c-fos may be a potential factor in the control of eye growth and play an important role in the signal transduction of retina.