Contribution of the clock gene DEC2 to VEGF mRNA upregulation by modulation of HIF1α protein levels in hypoxic MIO-M1 cells, a human cell line of retinal glial (M?ller) cells
Contribution of the clock gene DEC2 to VEGF mRNA upregulation by modulation of HIF1α protein levels in hypoxic MIO-M1 cells, a human cell line of retinal glial (M?ller) cells
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时钟基因 DEC2 通过调节缺氧 MIO-M1 细胞（视网膜胶质细胞 (M?ller) 细胞系）中的 HIF1α 蛋白水平来促进 VEGF mRNA 上调
DOI：
10.1007/s10384-018-0622-5
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发表时间：
2018
影响因子：
2.4
通讯作者：
Kubota Toshiaki
中科院分区：
文献类型：
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作者：
Kusunose Naoki;Akamine Takahiro;Kobayashi Yoshiyuki;Yoshida Shigeo;Kimoto Kenichi;Yasukochi Sai;Matsunaga Naoya;Koyanagi Satoru;Ohdo Shigehiro;Kubota Toshiaki
目的时钟基因是分子时钟的组成部分。它们的故障被认为会增加患多种疾病的风险，包括癌症。血管内皮生长因子(VEGF)在血管生成中起关键作用，其表达水平受肿瘤细胞时钟基因的调控。眼科疾病，如老年性黄斑变性、增殖性糖尿病视网膜病变和新生血管性青光眼，也与眼内血管生成异常和血管内皮生长因子上调有关。在本研究中，我们旨在揭示眼内时钟基因与血管内皮生长因子之间的关系。研究设计实验室研究方法制备氧诱导视网膜病变(OIR)小鼠，模拟眼内低氧条件。用去铁胺(DFO)模拟人Müler细胞系MIO-M1细胞的低氧状态。结果在OIR小鼠视网膜中，Vegf和时钟基因Dec2的表达水平一过性升高，且二者的时间分布呈正相关。在DFO诱导的模拟缺氧条件下，DEC2基因敲除后MIO-M1细胞中VEGFmRNA的表达显著降低(26.7%)(P<；0.05)。在针对DEC2基因的小干扰RNA处理的MIO-M1细胞中，HIF1α蛋白的水平也显著降低了60.2%(P<；0.05)。此外，HIF1α水平在高表达DEC2的MIO-M1细胞中显著增加(P<；0.05)。结论DEC2在低氧条件下通过调节HIF1α水平上调视网膜血管内皮生长因子基因的表达。
PurposeClock genes are components of the molecular clock. Their malfunction is thought to increase the risk of numerous diseases, including cancer. Vascular endothelial growth factor (VEGF) has a pivotal role in angiogenesis, and its expression levels are controlled by clock genes in tumor cells. Ophthalmic diseases such as age-related macular degeneration, proliferative diabetic retinopathy, and neovascular glaucoma are also associated with abnormal angiogenesis followed by upregulation of VEGF in the eye. In the present study, we aimed to uncover the relationship between clock genes and VEGF in the eye.Study designLaboratory investigationMethodsOxygen-induced retinopathy (OIR) mice were prepared to mimic hypoxic conditions in the eye. Deferoxamine (DFO) was used to mimic hypoxic conditions in human Müller cell line MIO-M1 cells. Expression levels of mRNA and protein were quantified by quantitative reverse transcription polymerase chain reaction and Western blot analysis, respectively.ResultsIn the retinas of OIR mice, the expression levels ofVegfand the clock geneDec2increased transiently, and their temporal profiles were correlated. Knockdown ofDEC2resulted in a significant (26.7%) reduction ofVEGFexpression in MIO-M1 cells under hypoxia-mimicking conditions induced by DFO (P< .05). Levels of HIF1α protein were also reduced significantly, by 60.2%, in MIO-M1 cells treated with siRNA against theDEC2gene (P< .05). Moreover, HIF1α levels showed a significant (2.5-fold) increase in MIO-M1 cells overexpressingDEC2(P< .05).ConclusionDEC2 could upregulate retinalVEGFgene expression through modulation of HIF1α levels under hypoxic conditions.