早期发育中缺乏 IRBP 的小鼠眼睛过度生长。
Exaggerated eye growth in IRBP-deficient mice in early development.
机构信息
Department of Ophthalmology, Emory University, Atlanta, Georgia 30322, USA.
出版信息
Invest Ophthalmol Vis Sci. 2011 Jul 29;52(8):5804-11. doi: 10.1167/iovs.10-7129.
PURPOSE
Because interphotoreceptor retinoid-binding protein (IRBP) is expressed before being needed in its presumptive role in the visual cycle, we tested whether it controls eye growth during development.
METHODS
The eyes of congenic IRBP knockout (KO) and C57BL/6J wild-type (WT) mice ranging in age from postnatal day (P)2 to P440 were compared by histology, laser micrometry, cycloplegic photorefractions, and partial coherence interferometry.
RESULTS
The size and weight of IRBP KO mouse eyes were greater than those of the WT mouse, even before eye-opening. Excessive ocular enlargement started between P7 and P10, with KO retinal arc lengths becoming greater compared with WT from P10 through P30 (18%; P < 0.01). The outer nuclear layer (ONL) of KO retinas became 20% thinner between P12 to P25, and progressed to 38% thinner at P30. At P30, there were 30% fewer cones per vertical section in KO than in WT retinas. Bromodeoxyuridine (BrdU) labeling indicated the same number of retinal cells were born in KO and WT mice. A spike in apoptosis was observed in KO outer nuclear layer at P25. These changes in size were accompanied by a large decrease in hyperopic refractive error, which reached -4.56 ± 0.70 diopters (D) versus +9.98 ± 0.993 D (mean ± SD) in WT, by postnatal day 60 (P60). CONCLUSIONS; In addition to its role in the visual cycle, IRBP is needed for normal eye development. How IRBP mediates ocular development is unknown.
目的
由于视黄醇结合蛋白（IRBP）在其在视觉循环中的预期作用之前表达，我们测试了它是否在发育过程中控制眼睛生长。
方法
通过组织学、激光微测、睫状肌麻痹光折射和部分相干干涉测量，比较了年龄在出生后第 2 天（P2）至 P440 之间的同基因 IRBP 敲除（KO）和 C57BL/6J 野生型（WT）小鼠的眼睛。
结果
IRBP KO 小鼠的眼睛大小和重量均大于 WT 小鼠，甚至在睁眼之前。过度的眼球增大始于 P7 至 P10 之间，KO 视网膜弧长从 P10 至 P30 开始比 WT 长（18%；P < 0.01）。KO 视网膜外核层（ONL）在 P12 至 P25 之间变薄了 20%，在 P30 时变薄了 38%。在 P30 时，KO 视网膜中每垂直切片的锥体数比 WT 少 30%。溴脱氧尿苷（BrdU）标记表明 KO 和 WT 小鼠中产生的视网膜细胞数量相同。在 P25 时，KO 外核层中观察到细胞凋亡增加。这些大小变化伴随着远视屈光不正的大幅下降，在 P60 时达到-4.56 ± 0.70 屈光度（D）与+9.98 ± 0.993 D（均值±SD）相比，WT 眼。
结论
除了在视觉循环中的作用外，IRBP 还需要正常的眼睛发育。IRBP 如何介导眼球发育尚不清楚。
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