TY - JOUR
T1 - Molecular pathophysiology of impaired glucose metabolism, mitochondrial dysfunction, and oxidative DNA damage in Alzheimer's disease brain
AU - Abolhassani, Nona
AU - Leon, Julio
AU - Sheng, Zijing
AU - Oka, Sugako
AU - Hamasaki, Hideomi
AU - Iwaki, Toru
AU - Nakabeppu, Yusaku
N1 - Funding Information:
This work was partly supported by grants from the Japan Society for the Promotion of Science (22221004, 15K15085), and the Science Research Grant for Dementia R&D from the Japan Agency for Medical Research and Development(AMED). Julio Leon is a research student under the MEXT (Ministry of Education, Culture, Sports, Science, and Technology, Japan) Scholarship Program. We thank associate professor Kunihiko Sakumi and assistant professor Daisuke Tsuchimoto for helpful discussions and assistant professor Antonio Jr. Prudente Formacion for English editing, and Setsuko Kitamura, Tsukasa Kuwano and Kaoru Nakabeppu for their technical assistance.
Publisher Copyright:
© 2016 Elsevier Ireland Ltd
PY - 2017/1/15
Y1 - 2017/1/15
N2 - In normal brain, neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. It has been shown that insulin resistance impairs glucose metabolism and mitochondrial function, thus increasing production of reactive oxygen species. Recent progress in Alzheimer's disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Among possible oxidative DNA lesions, 8-oxoguanine (8-oxoG) is highly accumulated in the brain of AD patients. Previously we have shown that incorporating 8-oxoG in nuclear and mitochondrial DNA promotes MUTYH (adenine DNA glycosylase) dependent neurodegeneration. Moreover, cortical neurons prepared from MTH1 (8-oxo-dGTPase)/OGG1 (8-oxoG DNA glycosylase)-double deficient adult mouse brains is shown to exhibit significantly poor neuritogenesis in vitro with increased 8-oxoG accumulation in mitochondrial DNA in the absence of antioxidants. Therefore, 8-oxoG can be considered involved in the neurodegenerative process in AD brain. In mild cognitive impairment, mitochondrial dysfunction and oxidative damage may induce synaptic dysfunction due to energy failures in neurons thus resulting in impaired cognitive function. If such abnormality lasts long, it can lead to vicious cycles of oxidative damage, which may then trigger the neurodegenerative process seen in Alzheimer type dementia.
AB - In normal brain, neurons in the cortex and hippocampus produce insulin, which modulates glucose metabolism and cognitive functions. It has been shown that insulin resistance impairs glucose metabolism and mitochondrial function, thus increasing production of reactive oxygen species. Recent progress in Alzheimer's disease (AD) research revealed that insulin production and signaling are severely impaired in AD brain, thereby resulting in mitochondrial dysfunction and increased oxidative stress. Among possible oxidative DNA lesions, 8-oxoguanine (8-oxoG) is highly accumulated in the brain of AD patients. Previously we have shown that incorporating 8-oxoG in nuclear and mitochondrial DNA promotes MUTYH (adenine DNA glycosylase) dependent neurodegeneration. Moreover, cortical neurons prepared from MTH1 (8-oxo-dGTPase)/OGG1 (8-oxoG DNA glycosylase)-double deficient adult mouse brains is shown to exhibit significantly poor neuritogenesis in vitro with increased 8-oxoG accumulation in mitochondrial DNA in the absence of antioxidants. Therefore, 8-oxoG can be considered involved in the neurodegenerative process in AD brain. In mild cognitive impairment, mitochondrial dysfunction and oxidative damage may induce synaptic dysfunction due to energy failures in neurons thus resulting in impaired cognitive function. If such abnormality lasts long, it can lead to vicious cycles of oxidative damage, which may then trigger the neurodegenerative process seen in Alzheimer type dementia.
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U2 - 10.1016/j.mad.2016.05.005
DO - 10.1016/j.mad.2016.05.005
M3 - Article
C2 - 27233446
AN - SCOPUS:84971602504
VL - 161
SP - 95
EP - 104
JO - Mechanisms of Ageing and Development
JF - Mechanisms of Ageing and Development
SN - 0047-6374
IS - Pt A
ER -