Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.
Exp Eye Res. 2011 Nov;93(5):700-9. doi: 10.1016/j.exer.2011.09.001. Epub 2011 Sep 14.
The DBA/2J (D2) and C57BL6 (B6) mouse strains are widely used in research as models for anxiety, addiction and chronic glaucoma. D2, but not B6, animals develop elevated intraocular pressure (IOP) that leads to progressive degeneration of retinal ganglion cell (RGC) axons and perikarya. Here we compare the expression and localization of intracellular ryanodine receptor (RyR) Ca(2+) store mechanisms in retinas from D2 and B6 animals. A subset of experiments included retinas from D2-Gpnmb(+) mice as strain-specific controls for D2s. RT-PCR analysis showed 6-8 -fold upregulation RyR1, but not RyR2 or RyR3 transcripts, in D2 retinas. The upregulation was more pronounced in D2 retinas categorized as exhibiting moderate or severe glaucoma eyes compared to eyes with no/little glaucoma. In B6 retinas, RyR1 was expressed in neuronal perikarya/processes across all three retinal layers whereas little labeling was observed in astrocyte, microglial or Müller cell processes. In contrast, RyR1 antibodies strongly labeled radial processes of in D2 Müller glia, in which the staining colocalized with the activated glial stress marker GFAP. RyR1 staining in 1 month-old D2-Gpnmb(+) strain resembled expression in B6 retinas whereas moderate RyR1, but not GFAP, localization to Müller glia was observed in 10-12 months - old D2-Gpnmb(+) eyes. Both RyR1-ir and GFAP-ir were augmented in the microbead injection model of acute experimental glaucoma. We conclude that RyR1 exhibits differential expression and localization in two ubiquitously used mouse lines. While RyR1 signals can be regulated in a strain-specific manner, our data also suggest that RyR1 transcription is induced by early glial activation and/or elevation in intraocular pressure.
DBA/2J（D2）和 C57BL6（B6）小鼠品系被广泛用于焦虑、成瘾和慢性青光眼的研究模型。D2 但不是 B6 动物会出现眼内压（IOP）升高，导致视网膜神经节细胞（RGC）轴突和胞体进行性变性。在这里，我们比较了 D2 和 B6 动物视网膜中细胞内ryanodine 受体（RyR）钙储存机制的表达和定位。部分实验包括 D2-Gpnmb（+）小鼠的视网膜作为 D2 的品系特异性对照。RT-PCR 分析显示，D2 视网膜中 RyR1 的转录物上调了 6-8 倍，但 RyR2 或 RyR3 转录物没有上调。在被归类为中度或重度青光眼眼的 D2 视网膜中，上调更为明显，而在没有/很少青光眼的眼中则不明显。在 B6 视网膜中，RyR1 在所有三个视网膜层的神经元胞体/突起中表达，而在星形胶质细胞、小胶质细胞或 Müller 细胞突起中几乎没有标记。相比之下，RyR1 抗体在 D2 Müller 胶质细胞的放射状突起中强烈标记，其染色与激活的胶质应激标志物 GFAP 共定位。1 个月大的 D2-Gpnmb（+）品系的 RyR1 染色类似于 B6 视网膜的表达，而在 10-12 个月大的 D2-Gpnmb（+）眼中观察到中等强度的 RyR1，但不是 GFAP，定位于 Müller 胶质细胞。微珠注射急性实验性青光眼模型中，RyR1-ir 和 GFAP-ir 均增加。我们得出结论，RyR1 在两种广泛使用的小鼠品系中表现出差异表达和定位。虽然 RyR1 信号可以以品系特异性的方式调节，但我们的数据还表明，RyR1 转录是由早期胶质细胞激活和/或眼内压升高诱导的。
