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burden, both SDS soluble and insoluble, in the brain of APP/PS1 mice. No

significant changes were observed in the levels of full-length APP, alpha- or

beta-C-terminal fragments; however, TBHQ significantly increased plasma

Ab level, suggesting that TBHQ decreases brain Ab burden not by decreas-

ing APP production or altering the processing of APP through a- or b-sec-

retases but probably by increasing excretion of Ab from the brain. PAI-1 is

a physiological inhibitor of tPA and uPA, which converts plasminogen into

plasmin, a serum protease playing an important role in Ab degradation. We

showed previously that PAI-1 protein level was increased in the brain of

APP/PS1 transgenic mice and in AD patients while knockout of the PAI-1

gene reduced Ab burden in APP/PS1 mice. Here we further showed that

TBHQ treatment significantly reduced PAI-1 protein level in the brain of

APP/PS1 mice, accompanied by an increase in tPA activity. Conclusions:

Together the data suggest that TBHQ treatment reduces brain Ab burden

in APP/PS1mice probably by inhibiting PAI-1 gene expression, which leads

to increasedAb degradation through plasmin, and by increasing excretion of

Ab from the brain. These results suggest a therapeutic value of TBHQ in the

treatment of AD.

P4-040 MEMORY SELF-APPRAISAL AND PET OF BRAIN

AMYLOID AND TAU IN PERSONS WITHOUT

DEMENTIA

David A. Merrill, Prabha Siddarth, Linda M. Ercoli, Alison C. Burggren,

Vladimir Kepe, Jeanne Kim, Helen Lavretsky, S.-C. Huang,

Susan Bookheimer, Jorge R. Barrio, Gary W. Small, UCLA, Los Angeles,

CA, USA. Contact e-mail: dmerrill@mednet.ucla.edu.

Background: As people age, the rate of self-reported memory complaints

increases. Whether such reports of memory symptoms parallel actual

changes in brain pathology is unknown. The pathological hallmarks of Alz-

heimer’s disease, amyloid senile plaques and tau neurofibrillary tangles, be-

gin to accumulate years before the development of dementia. Positron

emission tomography scans after intravenous injections of 2-(1-{6-[(2-[F-

18]fluoroethyl)(methyl)amino]-2-naphthyl}ethylidene)malononitrile

(FDDNP) provide a measure of plaques and tangles in vivo. Here we inves-

tigate whether self-reported memory complaints are associated with in-

creased cerebral FDDNP-PET binding. Methods: Design: Cross-sectional

clinical study. Setting:A university research institute. Participants:Volun-

teer sample of 57 middle-aged and older persons without dementia (mean

age, 66.3+10.6 years) including 25 with normal aging and 32 with mild cog-

nitive impairment (MCI), a risk state for Alzheimer’s disease. Main Out-

come Measures: The four factor scores of the Memory Functioning

Questionnaire (MFQ), which indicate frequency of forgetting, seriousness

of forgetting, retrospective functioning, and mnemonics use; FDDNP bind-

ing in medial and lateral temporal cortex, posterior cingulate gyrus, parietal

cortex, and frontal cortex regions of interest. Results: After controlling for

age, higher reported frequency of forgetting correlated significantly with

FDDNP binding globally (r ¼ -0.33, p ¼ .02) and in medial temporal (r

¼ -0.29, p ¼ 0.05), parietal (r ¼ -0.30, p ¼.03), and frontal (r ¼ -0.35, p

¼ 0.01) regions. The remaining MFQ scales were not significantly related

to FDDNP binding levels, and no significant differences were found be-

tween the normal aging and MCI subjects. Conclusions: These findings

suggest that self-awareness of memory loss, in particular the reported fre-

quency of forgetting,may reflect the extent of cerebral amyloid and tau brain

pathology in peoplewithout dementia. Such self-perceivedmemory abilities

might predict and track neuropathological changes in the brain years before

symptoms of dementia emerge.

P4-041 RESTRICTED V-GENES USAGE OF MOUSE

HUMORAL RESPONSE AGAINST THE EFRH

IMMUNODOMINANT EPITOPE OFAb

Remy Robert1, Marie-Paule Lefranc2, Anahit Ghochikyan3,

Michael G. Agadjanyan3, David H. Cribbs4, William E. Van Nostrand5,

Kim L. Wark1, Olan Dolezal1, 1CSIRO, Parkville, Australia; 2CNRS,

Montpellier, France; 3Institute for Molecular Medicine, Huntington Beach,

CA, USA; 4Institute for Brain Aging and Dementia, University of California

at Irvine, Irvine, CA, USA; 5Department of Medicine, Stony Brook Uni-

versity, Stony Brook, NY, USA.

Background:Over the last decade, success in experimental and clinical tri-

als using transgenic mice have provided great hope for antibodies as thera-

peutic strategies to treat Alzheimer’s Disease. Although, these approaches

have thus far produced undesirable side effects in humans, antibody thera-

pies remain one of the most promising treatments attracting considerable in-

vestment from both academics and pharmaceutical companies.Methods: In

this study, we analyzed the V-genes of eleven independently isolated mono-

clonal antibodies raised against the 3EFRH6 sequence, located at the N-ter-

minal region of the amyloid-b-peptide (Ab). Results: Surprisingly, we

found a high and unusual level of restriction in the VH/VL pairing of these

antibodies. We designed and produced a range of recombinant Fab con-

structs by variable domain exchange, HCDR3 loop replacement, germline

segment insertion and point mutations. All the Fab fragments were tested

and compared by surface plasmon resonance on Ab1-16 and high molecular

weight oligomers. Conclusions: The results emphasize the importance of

germline encoded residues and provide insight into how to elicit a humoral

immune response in order to generate conformational mouse monoclonal

antibodies.

P4-042 THE ROLE OF OXIDATIVE STRESS AND

AUTOPHAGY IN AMYLOID BETA-PROTEIN

TOXICITY TO CULTURED NEUROBLASTOMA

CELLS

Lin Zheng1, Nodi Dehvari2, Eirikur Benedikz2, Richard Cowburn3,

Alexei Terman4, Angel Cedazo-Minguez2, Jan Marcusson1, 1Linkoping

University, Linkoping, Sweden; 2Karolinska Institute, Stockholm, Sweden;3AstraZeneca R&D, Sodertalje, Sweden; 4Karolinska University Hospital,

Stockholm, Sweden. Contact e-mail: lin.zheng@liu.se.

Background: Increasing evidence suggests the toxicity of intracellular am-

yloid beta-protein (Ab) to neurons and the involvement of lysosomes in this

process in Alzheimer’s disease (AD). We have previously shown that oxida-

tive stress enhances autophagy and leads to intralysosomal accumulation of

Ab in cultured neuroblastoma cells. Furthermore, we have found that oxida-

tive stress can induce neuronal death through autophagy of Ab and conse-

quent lysosomal membrane permeabilization in cultured HEK293 cells.

Methods: To further investigate the involvement of autophagy in Ab cyto-

tocicity, we compared the effects of hyperoxia (exposure of cells to 40%

ambient oxygen for five days) in retinoic acid differentiated neuroblastoma

SH-SY5Y (neuronal-like) cells that were stably transfected with APPwt, or

APPswe or vector only. Autophagy was detected by immunofluorecsence

microscopy (immunoreactivity to LC3 and LAMP-2), western blotting (us-

ing antibodies to LC3) and electron microscopy. Reactive oxygen species

(ROS) were assessed by flow cytometry (DCFH oxidation method). Re-

sults:Hyperoxia-exposed neuroblastoma cells showed an increased content

of Ab-containing lysosomes/autophagic vacuoles, enhanced apoptosis, as

well as increased ROS production as compared to cells cultured at normoxic

conditions. This effect of hyperoxia was more pronounced in Ab-overpro-

ducing cells (vector<APPwt<APPswe). Furthermore, an inhibitor of mac-

roautophagy 3-methyladenine (3MA), prevented these effects of hyperoxia

in all neuroblastoma cell lines used in the study.Conclusions: These results

suggest that autophagy of Ab is crucial for oxidant-induced apoptosis in cul-

tured neuroblastoma cells. Theymay help better understanding of the mech-

anisms behind neuronal loss in AD and suggest new therapeutic approaches

for its management.

P4-043 ASSESSINGHEALTHRELATEDRESOURCE USE IN

NORMAL ELDERS AND SUBJECTS WITH MILD

COGNITIVE IMPAIRMENT

Carolyn Zhu1, Mary Sano1, Steven Ferris2, Paul Aisen3, 1Mount Sinai

School of Medicine, New York, NY, USA; 2New York University, New York,

NY, USA; 3University of California at San Diego, San Diego, CA, USA.

Contact e-mail: carolyn.zhu@mssm.edu.