Effect of Docosahexaenoic acid and AuNPs in N2A cells with Aβ

• Main Authors: Lu Wei Ling, 盧瑋翎
• Other Authors: Chiang MingChang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/q97pn7

碩士 === 輔仁大學 === 生命科學系碩士班 === 103 === Alzheimer disease (AD) is a primary type of dementia (60%–80%) and the most prevalent neurodegenerative disorder associated with aging. AD is characterized by progressive loss of memory and cognition, brain atrophy, and accumulation of amyloid plaques and neurofibrillary tangle. However, amyloid beta peptide (Aβ) is the main component of amyloid plaques (extracellular deposits found in the brains of patients with AD). In some studies show that Docosahexaenoic acid (DHA) supplementation caused a significant reduction in Aβ toxic that may have neuroprotection potential. Gold nanoparticles (AuNPs) a novel agent, has good biocompatibility and has been used in biomedical researches. Investigations suggest AuNPs can promote neurite outgrowth of N2A cells and significantly increase the neurite length that can be used as the index of differentiation potential. Recent studies suggested that AuNPs reduced mHtt aggregates in mHtt expressing (Huntington disease, HD) N2A cells. We used the toxin, Aβ, triggered N2A cell as model of AD. DHA and AuNPs were treated to cells respectively. We assessed the effects of Aβ, DHA and AuNPs on cell viability and Live/Dead dye kit in N2A cells. The result of MTT assay, N2A cells were treated with 2.5 M A(1-42) for 72 h, and cell viability was reduced significantly in A by MTT assay. Treatment of 5 M DHA may protect N2A cells from Aβ toxicity in cell viability. Treatment of 5 ppm AuNPs do not protect N2A cells from Aβ toxicity in cell viability. Live/Dead dye activity was detected after A treatment for 72 h, and was significantly different by A. The result of Live/Dead kit showed that treated with the 5M DHA or 5 ppm AuNPs from Aβ toxicity independently, the cell viability has no significant difference compared with 2.5 M Aβ. Microarray analysis was to compare the effect of Aβ with DHA and AuNPs related gene expression in N2A cells. The results showed that 78 genes were up regulated and 144 genes were down regulated in the Aβ trial when compared to the control trial. We confirmed the AuNPs (chemical and physical)can go through the cell membrane inside the N2A cells. The result of Transmission Electron Microscopy, we found that the average mitochondrial was shrinkage necrosis in N2A cells from Aβ toxicity. Treatment of AuNPs (chemical and physical) also made average mitochondrial shrinkage necrosis in N2A cells from Aβ toxicity. The DHA with Aβ trial showed that 390 genes were up-regulated and 355 genes were down-regulated compared to the control trial. The AuNPs with Aβ trial showed that 836 genes were up-regulated and 525 genes were down-regulated compared to the control trial. To extending our understanding, we will use QPCR and Western blot to confirm related gene and protein. Our findings will extend our understanding of the central role of DHA and AuNPs in Aβ-related neuronal impairment, which probably increase risks in neurodegenerative diseases.