The long-term goal of the proposed research is to understand the role of the voltage-dependent anion channel 1 (VDAC1) protein in Alzheimer's disease (AD) pathogenesis. Recent studies using postmortem AD brains, brain tissues from 6-, 12-, and 24-month-old A?PP transgenic mice, and primary neurons from A?PP and tau mice revealed that age, amyloid beta (A?)-, and phosphorylated (phospho) tau-induced mitochondrial dysfunction and oxidative stress are key factors involved in neuronal dysfunction in AD pathogenesis. Researchers have reported that A? is associated with mitochondria localized at synapses and with synaptic damage and mitochondrial dysfunction. Preliminary research revealed that VDAC1, located in the outer membrane of mitochondria, was higher in the cortical tissues from AD patients and was also higher in the cerebral cortices of the 6-, 12-, and 24-month-old A?PP mice. Research also revealed VDAC1 interacting with A? and phospho tau in the AD postmortem brains and in the cerebral cortices from APP, APPxPS1, and 3xAD.Tg mice. Mitochondrial functional analysis indicated increased free radicals, lipid peroxidation levels, and fission-linked GTPase activity, and decreased cytochrome oxidase and ATP levels in the APP transgenic mice. Preliminary research also indicated that A?-induced activated glycogen synthase kinase 3? (GSK3?) reduced hexokinases 1 and 2, and enhanced VDAC1 phosphorylation, leading to defects in mitochondrial structure/function. However, the links between A? and VDAC1 and between phospho tau and VDAC1 are unclear, and the relationship between GSK3? and VDAC1 phosphorylation to mitochondrial dysfunction are unclear. One hypothesis is that A? and phospho tau interact with VDAC1, which disrupts the transport of proteins/metabolites, resulting in defects in oxidative phosphorylation and in ATP synthesis. Another hypothesis is that a partial deficiency of VDAC1 maintains the mitochondrial pore activity in neurons producing A? and phospho tau, which in turn reduce mitochondrial dysfunction/synaptic damage in AD neurons. The proposed research objective is to determine the role of VDAC1 in mitochondrial dysfunction in relation to A? and phospho tau in AD pathogenesis. To this end, the proposed specific aims are: 1) to determine the physiological relevance of the interactions between VDAC1 and A?, and between VDAC1 and phosphorylated tau in relation to VDAC1 phosphorylation and hexokinase reductions in AD neurons, 2) to determine whether reduced VDAC1 maintains mitochondrial pore activity and mitochondrial function in neurons producing A? and 3) phosphorylated tau. The outcomes of the experiments for these aims will provide new insights into the physiological relevance of increased levels of VDAC1 and its interactions with A? and phosphorylated tau in AD pathogenesis~ and will provide critical information that can be used to develop therapies for reducing A?- and phosphorylated tau-induced mitochondrial damage and neuronal dysfunction in AD patients.

Public Health Relevance

Mitochondrial dysfunction is an early and prominent feature of Alzheimer's disease (AD) pathogenesis, but the precise mechanism underlying this dysfunction is still not well understood. The objectives of the proposed research are to determine the physiological relevance of the interactions between mitochondrial outer membrane protein, voltage-dependent anion channel 1 and amyloid beta/phosphorylated tau in AD neurons~ to determine whether partial reduction of voltage-dependent anion channel protein 1 maintains mitochondrial pore activity and mitochondrial function in neurons producing amyloid beta and phosphorylated tau. The outcomes of the proposed experiments will provide critical information that can be used to develop therapies for reducing amyloid beta- and phosphorylated tau-induced mitochondrial damage and neuronal dysfunction in AD patients.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
1R01AG047812-01
Application #
8723663
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Refolo, Lorenzo
Project Start
2014-05-15
Project End
2019-04-30
Budget Start
2014-05-15
Budget End
2015-04-30
Support Year
1
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Oregon Health and Science University
Department
Other Basic Sciences
Type
Primate Centers
DUNS #
City
Portland
State
OR
Country
United States
Zip Code
97239
Kandimalla, Ramesh; Manczak, Maria; Yin, Xiangling et al. (2018) Hippocampal phosphorylated tau induced cognitive decline, dendritic spine loss and mitochondrial abnormalities in a mouse model of Alzheimer's disease. Hum Mol Genet 27:30-40
Reddy, P Hemachandra; Yin, XiangLing; Manczak, Maria et al. (2018) Mutant APP and amyloid beta-induced defective autophagy, mitophagy, mitochondrial structural and functional changes and synaptic damage in hippocampal neurons from Alzheimer's disease. Hum Mol Genet 27:2502-2516
Vijayan, Murali; Kumar, Subodh; Yin, Xiangling et al. (2018) Identification of novel circulatory microRNA signatures linked to patients with ischemic stroke. Hum Mol Genet 27:2318-2329
Reddy, P Hemachandra; Manczak, Maria; Yin, Xiangling et al. (2018) Protective Effects of Indian Spice Curcumin Against Amyloid-? in Alzheimer's Disease. J Alzheimers Dis 61:843-866
Kumar, Subodh; Reddy, P Hemachandra (2018) MicroRNA-455-3p as a Potential Biomarker for Alzheimer's Disease: An Update. Front Aging Neurosci 10:41
Reddy, P Hemachandra; Manczak, Maria; Yin, XiangLing et al. (2018) Synergistic Protective Effects of Mitochondrial Division Inhibitor 1 and Mitochondria-Targeted Small Peptide SS31 in Alzheimer's Disease. J Alzheimers Dis 62:1549-1565
Pradeepkiran, Jangampalli Adi; Reddy, Arubala P; Reddy, P Hemachandra (2018) Pharmacophore-based models for therapeutic drugs against phosphorylated tau in Alzheimer's disease. Drug Discov Today :
Reddy, P Hemachandra (2017) A Critical Assessment of Research on Neurotransmitters in Alzheimer's Disease. J Alzheimers Dis 57:969-974
Bhatti, Jasvinder Singh; Bhatti, Gurjit Kaur; Reddy, P Hemachandra (2017) Mitochondrial dysfunction and oxidative stress in metabolic disorders - A step towards mitochondria based therapeutic strategies. Biochim Biophys Acta Mol Basis Dis 1863:1066-1077
Kuruva, Chandra Sekhar; Reddy, P Hemachandra (2017) Amyloid beta modulators and neuroprotection in Alzheimer's disease: a critical appraisal. Drug Discov Today 22:223-233

Showing the most recent 10 out of 40 publications