长波长缺失的连续光谱对小鼠屈光发育和实验性近视的影响及机制研究

In the previous studies,"outdoor time" has been proved to be an independent protective factor against myopia,which might be related to the mechanism that the inhibitory effect of high intensity light on myopia was mediated by dopamine (DA) pathway. However, it has also been proved that the inhibitory effect of "outdoor time"was not associated with the difference between the outdoor full-spectrum light and the indoor RGB light .It has been found that the long wavelength monochromatic light could promote the development of animal experimental myopia, which suggest us that the long-wavelength filtered continuous spectrum light may inhabit the progress of myopia.In this study, 3-week-old wild-type mouse, traditional D1 receptor knockout mouse,tissue specific D1 knockdown mouse,D1-RFP transgenetic mouse will be respectively reared in the full spectrum light and long-wavelength filtered continuous spectrum light,with or without lens-induced mopia treatment for 4 weeks,and combined with the intraperitoneal injection of dopamine D1 receptor agonists or antagonists among the tissue specific D1 knockdown mouse.They will undergo the measurements of refractive development parameters, the check of DA metabolite DOPAC content in vitreous, and the express of D1 receptor on retina and sclera, which aim to explain whether the long-wavelength filtered continuous spectrum light has an effect on the ocular growth and experimental myopia development,whether DA and D1 receptor are involved in this process, as well as the action site of D1 receptor and its mechanisms, and provide a theory evidence for the prevention and control of juvenile myopia.

既往研究发现“户外活动时长”是近视眼的独立保护因素，其机制是通过多巴胺（DA）通路介导的高强度光照对近视的抑制作用；户外全光谱光源与室内RGB光源的差异被证实不是户外活动时长抑制近视眼的机制，但长波长单色光促进动物实验性近视进展的研究结果提示：滤掉长波长的连续光谱可能抑制近视进展。本研究利用3周龄的野生型小鼠、全身D1受体敲除小鼠、视网膜或巩膜组织特异性D1受体敲减小鼠及D1－RFP转基因小鼠，用负透镜诱导实验性近视（LIM）,在全光谱或长波长缺失的连续光谱环境中饲养4周，并给组织特异性D1受体敲减小鼠腹腔注射多巴胺D1受体激动剂或拮抗剂，通过检测屈光发育参数、眼部玻璃体内DA代谢产物DOPAC的含量、视网膜和巩膜上D1受体的表达，明确长波长缺失的连续光谱是否对小鼠的屈光发育和实验性近视有影响，DA和D1受体是否参与此过程，D1受体在其中的作用部位和作用机制，为青少年近视防控提供理论依据。

随着青少年视力问题的日益加剧，青少年近视防控已经成为国策，受到举国重视。但是近视形成和发展的机制尚不清楚，户外活动、阿托品等用于控制近视发展的手段其作用机制也尚未明确。.户外活动抑制近视进展可能与户外自然光的光照强度和光谱特性有关。自然光具有高强度、全光谱的双重特性。我们通过特定的滤波装置（获得国家发明专利），得到3种不同的长波长缺失的连续光谱，并测试其在高、中、低光强照射下对豚鼠屈光发育的影响，研究发现，高强度光照能抑制近视进展和眼轴增长。在相对高的光照强度下(4000lux)，是光照强度而非光谱性质影响实验动物的屈光发育。当光照降至一定强度后(400lux、50lux)，滤掉特定长波长后的连续光谱能抑制实验动物的眼轴增长。.除了户外活动以外，阿托品控制近视的有效性已被多项临床试验证实。我们通过对形觉剥夺性近视（FDM）豚鼠玻璃体腔注射阿托品溶液，揭示了高浓度阿托品抑制短期FDM过程中所伴随的眼球形态及功能变化，首次发现阿托品在抑制豚鼠FDM进展的过程中引起被遮盖眼的脉络膜、全层视网膜及感光细胞层增厚，并使明适应ERGa波振幅升高，表明阿托品对外层视网膜具有保护作用，该保护作用可能主要针对视锥细胞。.有研究表明眼球巩膜上胶原纤维的大小和数量的减少是近视持续发展的发病机制之一，因此增强巩膜的机械力学强度可能是治疗近视的有效策略之一。京尼平已被证明是一种对巩膜胶原交联的安全有效的药物，有潜在的治疗近视的功效。我们进一步研究了京尼平可能引起的巩膜基因蛋白表达变化而产生对控制近视有益作用的分子机制，发现与正常对照眼相比，豚鼠近视眼巩膜中的 miR-29 簇和 MMP2 的表达增加，而 COL1A1 却减少。而经京尼平处理过的近视眼中却逆转了它们的表达这些影响。此外，我们发现 COL1A1 是 miR-29a和miR-29b 的直接靶向目标。我们的研究结果表明，京尼平可能通过下调豚鼠近视模型中的 miR-29 簇来增加 COL1A1 的表达。.该项目至今共发表SCI文章3篇，获得国家发明专利1项，培养博士毕业生2名。