Stein Eye Institute, University of California, Los Angeles, 100 Stein Plaza, Los Angeles, CA, 90095, USA.
Department of Psychiatry and Neurology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Sci Rep. 2020 Nov 12;10(1):19683. doi: 10.1038/s41598-020-76879-5.
Rbfox proteins regulate alternative splicing, mRNA stability and translation. These proteins are involved in neurogenesis and have been associated with various neurological conditions. Here, we analyzed Rbfox2 expression in adult and developing mouse retinas and the effect of its downregulation on visual function and retinal transcriptome. In adult rodents, Rbfox2 is expressed in all retinal ganglion cell (RGC) subtypes, horizontal cells, as well as GABAergic amacrine cells (ACs). Among GABAergic AC subtypes, Rbfox2 was colocalized with cholinergic starburst ACs, NPY (neuropeptide Y)- and EBF1 (early B-cell factor 1)-positive ACs. In differentiating retinal cells, Rbfox2 expression was observed as early as E12 and, unlike Rbfox1, which changes its subcellular localization from cytoplasmic to predominantly nuclear at around P0, Rbfox2 remains nuclear throughout retinal development. Rbfox2 knockout in adult animals had no detectable effect on retinal gross morphology. However, the visual cliff test revealed a significant abnormality in the depth perception of Rbfox2-deficient animals. Gene set enrichment analysis identified genes regulating the RNA metabolic process as a top enriched class of genes in Rbfox2-deficient retinas. Pathway analysis of the top 100 differentially expressed genes has identified Rbfox2-regulated genes associated with circadian rhythm and entrainment, glutamatergic/cholinergic/dopaminergic synaptic function, calcium and PI3K-AKT signaling.
Rbfox 蛋白调节选择性剪接、mRNA 稳定性和翻译。这些蛋白参与神经发生，并与各种神经疾病有关。在这里，我们分析了 Rbfox2 在成年和发育中的小鼠视网膜中的表达，以及其下调对视觉功能和视网膜转录组的影响。在成年啮齿动物中，Rbfox2 表达于所有视网膜神经节细胞 (RGC) 亚型、水平细胞以及 GABA 能无长突细胞 (AC)。在 GABA 能 AC 亚型中，Rbfox2 与胆碱能星爆 AC、NPY（神经肽 Y）和 EBF1（早期 B 细胞因子 1）阳性 AC 共定位。在分化的视网膜细胞中，早在 E12 就观察到 Rbfox2 的表达，与 Rbfox1 不同，Rbfox1 在 P0 左右从细胞质到主要核的亚细胞定位发生变化，Rbfox2 在整个视网膜发育过程中保持核定位。成年动物中的 Rbfox2 缺失对视网膜大体形态没有可检测到的影响。然而，视觉悬崖测试显示 Rbfox2 缺陷动物在深度知觉上存在显著异常。基因集富集分析确定调节 RNA 代谢过程的基因是 Rbfox2 缺失视网膜中最丰富的基因类别。对前 100 个差异表达基因的通路分析确定了 Rbfox2 调节的与昼夜节律和驯化、谷氨酸能/胆碱能/多巴胺能突触功能、钙和 PI3K-AKT 信号相关的基因。
