Monday, July 15, 2013: Poster Presentations: P2 P347

both size and color represented percent differences in metabolite levels

were easily distinguished across study groups. Edges were directional

and displayed as arrows where size represented percent difference in

flux and color the difference in expression level across study groups.

Colors ranged from green for decreases to brown for zero and orange to

red for increases. Pathways had to be mapped separately and some split

in order to allow visual analyses. Figure 1 shows the cholesterol pathway

comparing the aged with youngest group; note how easily one can assess

the extent of decrease in all metabolites and fluxes. Also note how even in

cases of increased gene expression (red arrows) flux was low because the

substrates were low. Export of maps into image files allowed assembly of

Powerpoint slides for film-strip inspections of pathway changes.

Conclusions: These results demonstrate the value of flux and metabolite

pathway mapping, especially with integrating gene expression changes.

Such complete pathway mapping is only.

P2-004 LONG-TERM TREATMENT WITH

CHOLINESTERASE INHIBITORS RESTORES

HOMEOSTATIC LEVELS OF CALCIUM-

INDEPENDENT PLA2: EVIDENCE OF DISEASE-

MODIFICATION IN ALZHEIMER’S DISEASE

Leda Talib1, Orestes Forlenza2, Sergio Hototian3, Wagner Gattaz4,1Laboratory of Neuroscience (LIM-27), Department and Institute of

Psychiatry, Faculty of Medicine, Un, S~ao Paulo, Brazil; 2University of S~aoPaulo, S~ao Paulo - S.P., Brazil; 3Laboratory of Neuroscience - University of

S~ao Paulo, S~ao Paulo, Brazil; 4USP, S~ao Paulo, Brazil.

Contact e-mail: ledatalib@gmail.com

Background: Decreased PLA2 activity and overactive glycogen synthase

kinase 3-beta (GSK3B) have been consistently found in the brain and pe-

ripheral tissues of patients with Alzheimer’s disease (AD). GSK3B has

a well-established role in the hyperphospholylation of TAU and modulation

of APP processing, and several PLA2 subtypes are critical to neuronal mem-

brane remodeling and subsequent formation of mediators of intracellular

signaling. In addition, reduced activity of calcium-independent PLA 2

(iPLA2) has been found in AD and may predict conversion to dementia in

patients with mild cognitive impairment. In spite of the well accepted symp-

tomatic benefit of cholinesterase inhibitors (CHEIs) on cognition and func-

tionality of patients with AD, little is known about their effects on GSK3B

and PLA2 in spite of both being modulated by cholinergic/muscarinic sig-

naling. Objective: To i nvestigate the effect of long-term treatment with

ChEIs on platelet GSK3B and PLA2 activity of patients with mild and mod-

erate AD. Methods: 36 unmedicated AD patients were recruited to this

study. The control group comprised 21 age-matched, healthy individuals.

Patients and controls were assessed at baseline with clinical and neuropsy-

chological instruments, and reassessed after 3 and 6 months after treatment.

PLA2 activity was determined in platelets by a radio-enzymatic assay. The

expression of total and Ser-9 phosphorylated GSK3B (tGSK3B and

pGSK3B respectively) was determined by Elisa method. Results: At base-

line iPLA2 activity and pGSK3B were decreased in patients with AD com-

paredwith controls (p¼ 0.02 and p¼0.017 respectively); no such differences

were found to c- and sPLA2 or to total GSK3B. After 6 months of

ChEI treatment, we observed a significant increase in iPLA2 activity

(p¼0,035), restoring enzymatic activity similar to that observed among con-

trols and a decrease in total GSK3B expression (p¼0.01) and in GSK3B ra-

tio (p¼0.008).Conclusions:Our preliminary results indicate that long-term

treatment with CHEIs restore homeostatic levels of iPLA2, but have no such

effect on GSK3B. Therefore cholinergic replacement therapy may have dis-

ease-modifying properties in certain biochemical pathways related to mem-

brane phospholipid metabolism, acting independently of GSK3B.

P2-005 LOW PLATELET PLA2 ACTIVITY PREDICTS

CONVERSION FROM MILD COGNITIVE

IMPAIRMENT TO ALZHEIMER’S DISEASE:

A 4-YEAR FOLLOW-UP STUDY

Wagner Gattaz1, Leda Talib2, Evelin Shaeffer3, Breno Diniz4,

Orestes Forlenza3, 1USP, S~ao Paulo, Brazil; 2Laboratory of Neuroscience

(LIM-27), Department and Institute of Psychiatry, Faculty of Medicine, Un,

S~ao Paulo, Brazil; 3Laboratory of Neuroscience - University of S~ao Paulo,

S~ao Paulo, Brazil; 4University of S~ao Paulo, S~ao Paulo, Brazil.

Contact e-mail: forlenza@usp.br

Background: Reduced phospholipase A 2 (PLA 2) activity has been re-

ported in the brain and in blood cells of patients with Alzheimer’s disease

(AD). Individuals with mild cognitive impairment (MCI) are at increased

risk of developing AD. In the present study, we determined the activity of

distinct PLA 2 subgroups (iPLA 2, sPLA 2 and cPLA 2) in older adults

with MCI as compared to patients with mild dementia due to AD and

to cognitively healthy controls. We investigated whether decreased PLA

2 activity at baseline is associated with the progression of MCI to AD

upon follow-up during a period of 4 years. Methods: The activity of

PLA 2 subgroups was determined in platelets from 169 elderly adults (44

AD, 59 amnestic MCI and 66 controls). Progression of MCI to AD was as-

certained by standard clinical criteria for AD upon follow-up. Results: At

baseline, iPLA 2 activity was significantly decreased (p¼ 0.001) in patients

with AD and MCI as compared to controls. Patients with MCI who pro-

gressed to AD during follow-up showed significantly lower iPLA2 activity

at baseline compared to patients with MCI who did not progress to AD (p¼0.009). Moreover, subjects from the control group at baseline who pro-

gressed to MCI during follow-up had lower sPLA2 and cPLA2 (p ¼0.014 and p ¼ 0.009 respectively). Conclusions: Our findings suggest

that low platelet iPLA 2 activity may be a risk marker for AD in subjects

with MCI. Moreover, low sPLA2 and cPLA2 were related to cognitive de-

cline in healthy controls, suggesting a relationship with the very early stages

of the disease. It is conceivable that the determination of PLA 2 activities

may enhance the predictive power of other biomarkers, such as CSF A

b 42 and Tau protein, in the early diagnosis of AD.

P2-006 TN ANTIGEN IN THE BRAIN: A NEWLY

RECOGNIZEDGLYCOPROTEIN INALZHEIMER’S

DISEASE

Parviz Lalezari1, Rukmani Lekhraj2, Bryan Kimiabakhsh2,

Emilce Carrasco2, Diana Casper3, 1Montefiore Medical Center, Albert

Enstein College of Medicine, Bronx, New York, United States; 2Montefiore

Medical Center, Bronx, New York, United States; 3Montefiore Medical

Center and the Albert Einstein College of Medicine, Bronx, New York,

United States. Contact e-mail: Lalezari2@aol.com

Background:Although abnormalities in glycoproteins and glycolipids have

been demonstrated in AD, their relationship to the pathogenesis of the

disease has remained unclear. This study focuses on N-acetylgalactosamine

(GalNAc) O-linked to proteins through serine or threonine that, with the

addition of galactose by the galactosyl transferase enzyme, constitutes

Core 1 glycoproteins. In polyagglutinability syndrome, an erythrocyte

abnormality, and in many malignancies, deficits in the transfer of galactose

to GalNAc cause a reduction in levels of sialic acid and exposure of an

epitope called Tn antigen.We hypothesized that a similar abnormality exists

in AD.Methods: Brain tissue specimens from late-onset AD cases included

hippocampal tissue sections from 14 cases and homogenates from 7 and sec-

tions of frontal cortex from 10 cases and homogenates from 9. Age-matched

controls included 4 sections and 7 homogenates from hippocampus, and

5 sections and 5 homogenates from cortex. Expression of Tn was examined

by immunohistochemistry using a monoclonal anti-Tn antibody. Western

blotting identified Tn-immunoreactive glycoproteins.Results: The distribu-

tion of Tn immunostaining in non-AD brain was generally sparse, with

occasional positive neurons. In contrast, stained pyramidal and granule neu-

rons were more abundant and more intense in AD cases. Neuropil staining

was also observed. In some AD cases, staining was lower in the CA1 region,

which is associated with the greatest neuronal loss. Tn was also present

within the hilus of the dentate gyrus, a region associated with neuronal pro-

genitors. Tn-immunoreactive bandswere identified in both hippocampal and

cortical homogenates, but not in CSF. Band intensities were approximately

two-fold greater in AD cases compared to controls. Preliminary data suggest

that some but not all bands represent glycosylated amyloid and tau proteins.