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[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

Received: 2008-11-06　　Accepted: 2008-12-22

Corresponding author: 张策　　E-mail: Cezh2002@yahoo.com

Citing This Article：

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).