Division of Life Science and Center for Chinese Medicine, The Hong Kong University of Science and Technology, Hong Kong, China.
Shenzhen Key Laboratory of Edible and Medicinal Bioresourses, Shenzhen Research Institute, Shenzhen, China.
J Neurochem. 2018 Aug;146(4):390-402. doi: 10.1111/jnc.14448. Epub 2018 Jul 23.
Acetylcholinesterase (AChE; EC 3.1.1.7) is known to hydrolyze acetylcholine at cholinergic synapses. In mammalian erythrocyte, AChE exists as a dimer (G ) and is proposed to play role in erythropoiesis. To reveal the regulation of AChE during differentiation of erythroblast, erythroblast-like cells (TF-1) were induced to differentiate by application of erythropoietin (EPO). The expression of AChE was increased in parallel to the stages of differentiation. Application of EPO in cultured TF-1 cells induced transcriptional activity of ACHE gene, as well as its protein product. This EPO-induced event was in parallel with erythrocytic proteins, for example, α- and β-globins. The EPO-induced AChE expression was mediated by phosphorylations of Akt and GATA-1; because the application of Akt kinase inhibitor blocked the gene activation. Erythroid transcription factor also known as GATA-1, a downstream transcription factor of EPO signaling, was proposed here to account for regulation of AChE in TF-1 cell. A binding sequence of GATA-1 was identified in ACHE gene promoter, which was further confirmed by chromatin immunoprecipitation (ChIP) assay. Over-expression of GATA-1 in TF-1 cultures induced AChE expression, as well as activity of ACHE promoter tagged with luciferase gene (pAChE-Luc). The deletion of GATA-1 sequence on the ACHE promoter, pAChE -Luc, reduced the promoter activity during erythroblastic differentiation. On the contrary, the knock-down of AChE in TF-1 cultures could lead to a reduction in EPO-induced expression of erythrocytic proteins. These findings indicated specific regulation of AChE during maturation of erythroblast, which provided an insight into elucidating possible mechanisms in regulating erythropoiesis.
乙酰胆碱酯酶（AChE；EC3.1.1.7）已知在胆碱能突触处水解乙酰胆碱。在哺乳动物的红细胞中，AChE 以二聚体（G）的形式存在，并被提议在红细胞生成中发挥作用。为了揭示 AChE 在红母细胞分化过程中的调节作用，用促红细胞生成素（EPO）诱导红母细胞样细胞（TF-1）分化。AChE 的表达与分化阶段平行增加。在培养的 TF-1 细胞中应用 EPO 诱导 ACHE 基因及其蛋白产物的转录活性。这种 EPO 诱导的事件与红细胞蛋白（例如α-和β-球蛋白）平行发生。EPO 诱导的 AChE 表达是通过 Akt 和 GATA-1 的磷酸化介导的；因为 Akt 激酶抑制剂的应用阻断了基因激活。红细胞转录因子也称为 GATA-1，是 EPO 信号转导的下游转录因子，据推测它负责调节 TF-1 细胞中的 AChE。在 ACHE 基因启动子中鉴定到 GATA-1 的结合序列，通过染色质免疫沉淀（ChIP）实验进一步证实。在 TF-1 培养物中过表达 GATA-1 诱导 AChE 表达以及带有荧光素酶基因（pAChE-Luc）的 ACHE 启动子的活性。在 ACHE 启动子上缺失 GATA-1 序列，pAChE-Luc，在红母细胞分化过程中降低启动子活性。相反，在 TF-1 培养物中敲低 AChE 会导致 EPO 诱导的红细胞蛋白表达减少。这些发现表明 AChE 在红母细胞成熟过程中受到特异性调节，这为阐明调节红细胞生成的可能机制提供了深入了解。
