Nicotine Promotes AβPP Nonamyloidogenic Processing via RACK1-Dependent Activation of PKC in SH-SY5Y-AβPP695 Cells
Nicotine Promotes AβPP Nonamyloidogenic Processing via RACK1-Dependent Activation of PKC in SH-SY5Y-AβPP695 Cells
复制标题
尼古丁通过 SH-SY5Y-AβPP695 细胞中 RACK1 依赖性 PKC 激活促进 AβPP 非淀粉样蛋白生成过程
DOI：
10.3233/jad-200003
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发表时间：
2020-01-01
影响因子：
4
通讯作者：
Dong, Zhifang
中科院分区：
文献类型：
--
作者：
He, Wenting;Tu, Man;Dong, Zhifang
背景资料：由淀粉样蛋白-β前体蛋白（A β PP）淀粉样蛋白生成加工产生的淀粉样蛋白-β（A β）肽的积累是阿尔茨海默病（AD）最显著的疾病标志之一。尼古丁能够促进α-分泌酶介导的A β PP非淀粉样蛋白生成加工，并增加sA β PP α和83个氨基酸（C83）的C端片段的释放。目的：研究尼古丁对稳定表达人Swedish突变型A β PP 695的SH-SY 5 Y细胞A β PP加工的影响方法：在尼古丁处理6 h的SH-SY 5 YA β PP 695细胞中，测量A β PP及其C-末端片段（包括C99、C89和C83）的表达。蛋白激酶C（PKC）拮抗剂Ro 30 -8220或激动剂PMA用于确定PKC在A β PP加工中的作用。结果：尼古丁暴露6 h后，α-分泌酶（ADAM 10）和C83的表达量呈剂量依赖性增加，而A β PP的表达量则呈剂量依赖性增加。而β-分泌酶（BACE 1）、A β PP淀粉样蛋白生成加工产物C89和C99以及A β肽（包括A β（40）和A β（42））保持不变。尼古丁还可上调细胞膜上磷酸化PKC（P-PKC）和RACK 1的表达。PKC拮抗剂Ro 30 -8220处理可抑制尼古丁引起的ADAM 10和C83的升高。结论：尼古丁通过RACK 1依赖性激活PKC，有效地促进SH-SY 5 Y-A β PP 695细胞A β PP非淀粉样蛋白生成过程，可能是治疗AD的潜在分子。
Background: Accumulation of amyloid-beta (A beta) peptides, generated from amyloid-beta precursor protein (A beta PP) amyloidogenic processing, is one of the most salient disease hallmarks of Alzheimer's disease (AD). Nicotine is able to promote alpha-secretase-mediated A beta PP nonamyloidogenic processing and increase the release of sA beta PP alpha and C-terminal fragment of 83 amino acids (C83). However, the potential molecular mechanism remains elusive.Objective: The aim of the present study was to investigate the effect of nicotine on A beta PP processing in SH-SY5Y cells that stably express human Swedish mutant A beta PP695 (SH-SY5Y-A beta PP695).Methods: The expression of A beta PP and its C-terminal fragments including C99, C89, and C83, was measured in SH-SY5YA beta PP695 cells treated with nicotine for 6 h. Protein kinase C (PKC) antagonist Ro30-8220 or agonist PMA was used to determine the role of PKC in A beta PP processing. Lentivirus-mediated shRNA targeting receptor for activated C-kinase 1 (RACK1) gene was added into the media to knockdown RACK1 expression, and then A beta PP processing was examined.Results: The results showed that 6 h of nicotine exposure increased the expression of alpha-secretase (ADAM10) and C83 in a dose dependent manner. While the beta-secretase (BACE1), A beta PP amyloidogenic processing products C89 and C99 as well as A beta peptides (including A beta(40) and A beta(42)) remained unchanged. We also found that nicotine elevated the expression of phosphorylated PKC (P-PKC) and RACK1 on the cytomembrane. PKC antagonist Ro30-8220 treatment prevented the increase of ADAM10 and C83 by nicotine. Genetic knockdown RACK1 significantly inhibited P-PKC, and consequently abolished the increase of ADAM10 and C83 by nicotine.Conclusion: Taken together, these results indicate that nicotine effectively promotes A beta PP nonamyloidogenic processing via RACK1-dependent activation of PKC in SH-SY5Y-A beta PP695 cells and could be a potential molecule for AD treatment.