Protective effects of [Gly14]-Humanin on beta-amyloid-induced PC12 cell death by preventing mitochondrial dysfunction.
, Liu T
, Wang WX
, Xu JH
, Yang PB
, Lu HX
, Sun QR
, Hu HT
Department of Human Anatomy and Histoembryology, Xi'an Jiaotong University College of Medicine, No.76 Yanta Xi Lu, Xi'an, Shaanxi 710061, People's Republic of China.
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Mitochondrial dysfunction is a hallmark of beta-amyloid (Abeta)-induced neuronal toxicity in Alzheimer's disease (AD), and is considered as an early event in AD pathology. Humanin (HN) and its derivative, [Gly14]-Humanin (HNG), are known for their ability to suppress neuronal death induced by AD-related insults in vitro and in vivo. In the present study, we investigated the neuroprotective effects of HNG on Abeta(25-35)-induced toxicity and its potential mechanisms in PC12 cells. Exposure of PC12 cells to 25muM Abeta(25-35) caused significant viability loss and cell apoptosis. In addition, decreased mitochondrial membrane potential and increased cytochrome c release from mitochondria were also observed after Abeta(25-35) exposure. All these effects induced by Abeta(25-35) were markedly reversed by HNG. Pretreatment with 100nM HNG 6h prior to Abeta(25-35) exposure significantly elevated cell viability, reduced Abeta(25-35)-induced cell apoptosis, stabilized mitochondrial membrane potential, and blocked cytochrome c release from mitochondria. Furthermore, HNG also ameliorated the Abeta(25-35)-induced Bcl-2/Bax ratio reduction and decreased caspase-3 activity in PC12 cells. These results demonstrate that HNG could attenuate Abeta(25-35) -induced PC12 cell injury and apoptosis by preventing mitochondrial dysfunction. Furthermore, these data suggest that mitochondria are involved in the protective effect of HNG against Abeta(25-35).
PMID: 19941922 [PubMed - as supplied by publisher]