过刊浏览

Humanin 拮抗Aβ31-35 引起的培养皮层神经元胞内Ca2+ 浓度升高

李灵敏, 乔健天, 张策

山西医科大学 病理学教研室； 生理学教研室，太原 030001

摘要

β- 淀粉样蛋白(β-amyloid protein, Aβ)在脑组织中的过多沉积与阿尔茨海默病(Alzheimer’s disease, AD)的发病密切相 关。Aβ 的毒性作用机制目前尚不明确，有研究认为扰乱细胞内钙稳态是其重要机制之一。Aβ 31-35 是一个小的Aβ 活性片 段，具有与完整肽链相同的神经毒作用。Humanin (HN)是一种存在于AD 患者脑组织中具有神经保护作用的多肽，它能 有效抑制Aβ 诱发的神经元死亡。本研究应用Ca2+ 荧光成像技术，检测不同时间给予不同浓度的HN 对Aβ31-35 引起的培养 皮层神经元[Ca2+]i 升高的影响，探讨HN 对Aβ31-35 神经毒的抑制作用是否通过抑制Aβ31-35 所致的细胞内钙稳态紊乱而实现。 结果显示：HN (10 μmol/L)预孵育10 min 部分抑制Aβ31-35 (25 μmol/L)所致的神经元 [Ca2+]i 的升高。当HN 与Aβ31-35 (25 μmol/L) 同时加入时，10 μmol/L HN 未能改变Aβ31-35 (25 μmol/L)引起的神经元[Ca2+]i 升高的幅度，但可延迟[Ca2+]i 的升高；而20 μmol/L HN 明显抑制了Aβ31-35 (25 μmol/L)引起的神经元[Ca2+]i 的升高。以上实验结果提示，Aβ31-35 引起神经细胞内钙稳态 的紊乱是其神经毒作用机制之一；HN 抑制Aβ 31-35 引起的神经元[Ca2+]i 升高具有时间和剂量依赖性。

关键词： 阿尔茨海默病; β - 淀粉样蛋白31-35; Humanin; 胞内钙离子

分类号：R329

[Effects of humanin on elevation of intracellular calcium concentration induced by β-amyloid peptide31-35 in cultured cortical neurons.] [Ariticle in Chinese]

LI Ling-Min, QIAO Jian-Tian, ZHANG Ce

Department of Pathology； Department of Physiology, Shanxi Medical University, Taiyuan 030001, China

Abstract

The disruption of the intracellular Ca2+ homeostasis has been reported to be one of the mechanisms of β-amyloid (Aβ) neurotoxicity in Alzheimer’s disease (AD). Aβ31-35, a small active fragment of Aβ, is believed to possess the similar biological activities of full-length Aβ molecule. Humanin (HN) is a recently identified peptide that suppresses neuronal death initiated by AD-related insults. The present study was to investigate the effects of HN on Aβ31-35-induced elevation of [Ca2+]i in cultured cortical neurons by real-time fluorescence imaging technique using the Ca2+-sensitive dye, Fura-2/AM. The elevation of [Ca2+]i was observed in cultured neurons exposed to Aβ31-35 (25 μmol/L) (F340/F380: 1 042.56±83.54, compared with control group: 804.73±48.23, P<0.05, n=10). Pretreatment of HN (10 μmol/L) for 10 min significantly decreased the elevation of [Ca2+]i induced by Aβ31-35 (25 μmol/L) (F340/F380: 918.79±50.73, compared with Aβ31-35 group, P<0.05, n=10). When neurons were treated with HN and Aβ31-35 simultaneously, HN (10 μmol/L) could not change the elevation of [Ca2+]i induced by Aβ31-35 (F340/F380: 1 036.68±88.96, compared with Aβ31-35 group, P>0.05, n=10), while HN (20 μmol/L) diminished the elevation of [Ca2+]i induced by Aβ31-35 (25 μmol/L) significantly (F340/F380: 898.56±76.46, compared with Aβ31-35 group, P<0.05, n=10). The findings imply that: (1) the disruption of the calcium homeostasis induced by Aβ31-35 is possibly the basis of the neurotoxicity of Aβ31-35 in cultured cortical neurons; (2) HN suppresses the elevation of [Ca2+]i induced by Aβ31-35 in a dose- and time-dependent manner.

Key words: Alzheimer’s disease; Aβ31-35; humanin; [Ca2+]i

收稿日期：2008-11-06　　录用日期：2008-12-22

通讯作者：张策　　E-mail: Cezh2002@yahoo.com

引用本文：

李灵敏, 乔健天, 张策. Humanin 拮抗Aβ31-35 引起的培养皮层神经元胞内Ca2+ 浓度升高[J]. 生理学报 2009; 61 (2): 127-131.

LI Ling-Min, QIAO Jian-Tian, ZHANG Ce. [Effects of humanin on elevation of intracellular calcium concentration induced by β-amyloid peptide31-35 in cultured cortical neurons.] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (2): 127-131 (in Chinese with English abstract).