Protective effects of [Gly14]-Humanin on beta-amyloid-induced PC12 cell death by preventing mitochondrial dysfunction.
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 25 microM Abeta(25-35) caused significant viability loss and cell apoptosis. In addition, decreased mitochondrial membrane potential and increased cytochrome c releases 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 100 nM 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).
Jin
Hui
H
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.
Liu
Tao
T
Wang
Wei-Xi
WX
Xu
Jie-Hua
JH
Yang
Peng-Bo
PB
Lu
Hai-Xia
HX
Sun
Qin-Ru
QR
Hu
Hai-Tao
HT
D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000633:toxicity; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology* / Q000627:therapeutic use; D008564:Membrane Potentials / Q000502:physiology; D053858:Metabolic Networks and Pathways / Q000187:drug effects / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D028361:Mitochondrial Diseases / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D009410:Nerve Degeneration / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016716:PC12 Cells; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000633:toxicity; D051381:Rats
D016229:Amyloid beta-Peptides; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; D018696:Neuroprotective Agents; D010446:Peptide Fragments; C074636:amyloid beta-protein (25-35); C427211:humanin