Chen Kui, Lu You, Peng Fang, Yu Hui-Ling, Wu Jia-Yan, Tan Yan, Zhao Yan-Xin
Department of Neurology, Shanghai Tenth People's Hospital, Tongji University, School of Medicine, 301 Middle Yanchang Road, Shanghai 200072, P. R. China.
Department of Neurology & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, P. R. China.
J Integr Neurosci. 2020 Mar 30;19(1):51-64. doi: 10.31083/j.jin.2020.01.1203.
encodes transglutaminase 6, which catalyzes the covalent crosslinking of proteins through transamination reactions. Variants in have been identified as the cause of spinocerebellar ataxia type 35. However, we found 12 variants of low frequency among 308 patients with Parkinson's disease using next-generation sequencing technologies and multiple ligation-dependent probe amplification, including two variants p.R111C and p.L517W, which have been reported to affect functions of transglutaminase 6 in spinocerebellar ataxia type 35 cases. The characteristics of these carriers were summarized. To clarify the role of variants in Parkinson's disease, we constructed the plasmids of wild-type and p.R111C, p.P359L, p.L517W to transfect A53T-SH-SY5Y cells and conducted transglutaminase assay, western blots, immunofluorescence, and cell viability assay. Results revealed that the distribution and expression levels of transglutaminase 6 were not affected by variants. However, the variants showed lower transglutaminase activity than wild-type transglutaminase 6. The overexpression of wild-type was proved to relieve the cell damage, down-regulate the level of α-synuclein and enhance autophagy. These effects were weakened in cells transfected with mutant plasmids. Our results suggested that there may be some relationship between and Parkinson's disease. carriers in Parkinson's disease patients presented with typical parkinsonism but progressed slower. The high expression level of wild-type transglutaminase 6 may protect cells by decreasing α-synuclein and enhancing autophagy.
编码转谷氨酰胺酶6，该酶通过转氨反应催化蛋白质的共价交联。已确定该基因的变异是35型脊髓小脑共济失调的病因。然而，我们使用下一代测序技术和多重连接依赖探针扩增，在308例帕金森病患者中发现了12个低频变异，其中包括两个变异p.R111C和p.L517W，据报道这两个变异在35型脊髓小脑共济失调病例中会影响转谷氨酰胺酶6的功能。总结了这些变异携带者的特征。为了阐明该基因变异在帕金森病中的作用，我们构建了野生型该基因以及p.R111C、p.P359L、p.L517W的质粒，转染A53T-SH-SY5Y细胞，并进行转谷氨酰胺酶检测、蛋白质印迹、免疫荧光和细胞活力检测。结果显示，转谷氨酰胺酶6的分布和表达水平不受该基因变异的影响。然而，这些变异的转谷氨酰胺酶活性低于野生型转谷氨酰胺酶6。野生型该基因的过表达被证明可减轻细胞损伤、下调α-突触核蛋白水平并增强自噬。在用突变型该基因质粒转染的细胞中，这些作用减弱。我们的结果表明该基因与帕金森病之间可能存在某种关系。帕金森病患者中的该基因变异携带者表现出典型的帕金森综合征，但进展较慢。野生型转谷氨酰胺酶6的高表达水平可能通过降低α-突触核蛋白和增强自噬来保护细胞。
