Key Laboratory of Protein Chemistry and Developmental Biology, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.
The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, #7 Jinsui Road, Guangzhou, Guangdong 510230, China.
Curr Mol Med. 2019;19(1):48-53. doi: 10.2174/1566524019666190311094313.
It has been well established that sumoylation acts as an important regulatory mechanism that controls many different cellular processes. We and others have shown that sumoylation plays an indispensable role during mouse eye development. Whether sumoylation is implicated in ocular pathogenesis remains to be further studied. In the present study, we have examined the expression patterns of the de-sumoylation enzymes (SENPs) in the in vitro cataract models induced by glucose oxidase and UVA irradiation.
Four-week-old C57BL/6J mice were used in our experiments. Lenses were carefully dissected out from mouse eyes and cultured in M199 medium for 12 hours. Transparent lenses (without surgical damage) were selected for experimentation. The lenses were exposed to UVA for 60 min or treated with 20 mU/mL glucose oxidase (GO) to induce cataract formation. The mRNA levels were analyzed with qRT-PCR. The protein levels were determined with western blot analysis and quantitated with Image J.
GO treatment and UVA irradiation can induce cataract formation in lens cultured in vitro. GO treatment significantly down-regulated the mRNA levels for SENPs from 50% to 85%; on the other hand, expression of seven SENP proteins under GO treatment appeared in 3 situations: upregulation for SENP1, 2 and 6; downregulation for SENP 5 and 8; and unchanged for SENP3 and 7. UVA irradiation upregulates the mRNAs for all seven SENPs; In contrast to the mRNA levels for 7 SENPs, the expression levels for 6 SENPs (SENP1-3, 5-6 and 8) appeared down-regulated from 10% to 50%, and only SENP7 was slightly upregulated.
Our results for the first time established the differentiation expression patterns of 7 de-sumoylation enzymes (SENPs) under treatment by GO or UVA, which provide preliminary data to link sumoylation to stress-induced cataractogenesis.
泛素化作用作为一种重要的调控机制，控制着许多不同的细胞过程，这一点已得到充分证实。我们和其他人已经表明，泛素化在小鼠眼睛发育过程中起着不可或缺的作用。泛素化是否与眼部发病机制有关仍有待进一步研究。在本研究中，我们检查了去泛素化酶（SENPs）在葡萄糖氧化酶和 UVA 照射诱导的体外白内障模型中的表达模式。
本实验使用 4 周龄 C57BL/6J 小鼠。从老鼠眼睛中小心地取出晶状体，并在 M199 培养基中培养 12 小时。选择透明晶状体（无手术损伤）进行实验。晶状体暴露于 UVA 照射 60 分钟或用 20mU/ml 葡萄糖氧化酶（GO）处理以诱导白内障形成。用 qRT-PCR 分析 mRNA 水平。用 Western blot 分析测定蛋白质水平，并用量化图像 J 进行定量。
GO 处理和 UVA 照射可诱导体外培养的晶状体白内障形成。GO 处理显著下调 SENPs 的 mRNA 水平，从 50%下调至 85%；另一方面，GO 处理下 7 种 SENP 蛋白的表达出现 3 种情况：SENP1、2 和 6 上调；SENP5 和 8 下调；SENP3 和 7 不变。UVA 照射上调所有 7 种 SENPs 的 mRNA；与 7 种 SENP 的 mRNA 水平相反，6 种 SENP（SENP1-3、5-6 和 8）的表达水平从 10%下调至 50%，只有 SENP7 略有上调。
我们的研究结果首次建立了 GO 或 UVA 处理下 7 种去泛素化酶（SENPs）的差异表达模式，为泛素化与应激诱导性白内障形成的关系提供了初步数据。
