Poster Presentations P2
P324 P2-216
ANTI-AMNESTIC AND NEUROPROTECTIVE ACTIVITIES OF ANAVEX2-73: A NEW AMINOTETRAHYDROFURAN DERIVATIVE ACTING AS A MIXED MUSCARINIC/SIGMA-1 LIGAND, IN PHARMACOLOGICAL AND PATHOLOGICAL MODELS OF AMNESIA
Vanessa Villard1, Julie Espallergues1, Alexandre Vamvakides2, Tangui Maurice1, 1UM2/Inserm U.710/EPHE, Montpellier Cedex 05, France; 2ANAVEX Life Science, Pallini, Greece. Contact e-mail: aliev03@ gmail.com Background: Tetrahydro-N,N-dimethyl-2,2-diphenyl-3-furanmethanamine (ANAVEX2-73) is a new sigma-1 receptor (S1R) ligand, with a sub-micromolar affinity (IC50¼860 nM & Ki¼710 nM) and low affinities (IC50¼3.35.2 mM) for M1-M4 muscarinic receptors. No affinity was found for sigma-2 receptors. Methods: The anti-amnesic abilities of ANAVEX2-73 were examined in several models of pharmacological and pathological amnesia in mice submitted to a short-term and long-term memory test, spontaneous alternation and passive avoidance, respectively. Results: The compound failed to affect the learning abilities alone, but reversed in a bell-shaped manner the deficits induced by the M1 muscarinic antagonist scopolamine, the NMDA receptor antagonist dizocilpine, or the central injection of amyloid beta(2535)-peptide (Ab25-35), a nontransgenic mouse model of Alzheimer’s disease (AD). These effects were blocked by a pre-injection of the S1R antagonist BD1047, confirming an action at S1R sites. Moreover, we examined the neuroprotective effects of ANAVEX2-73 in Ab-treated mice. Central injection of Ab25-35 into the mouse brain induces within 7 days histological and biochemical changes, oxidative stress and learning deficits. Injection of scrambled Ab peptide was used as control. ANAVEX2-73 was injected once, 20 min before Ab25-35 and 7 days before the behavioral tests and biochemical analyses. ANAVEX2-73 dose-dependently prevented the appearance of Ab25-35-induced learning deficits, at 30-1000 mg/kg, the same dose-range as observed for acute anti-amnesic effects. ANAVEX2-73 prevented the Ab25-35-induced increase in lipid peroxidation and caspase-3 expression in the hippocampus. Conclusions: The neuroprotective effects at the behavioral and biochemical levels were differentially sensitive to pre-treatments with either BD1047 or scopolamine, indicating a mixed mechanism of action involving S1R and muscarinic systems. P2-217
SILVER NANOPARTICLES AS ALTERNATE STRATEGIES FOR DRUG DELIVERY TO ALZHEIMER BRAIN
Gjumrakch Aliev1, Jesu´s Daza1, Amanda Lipsitt2, Marı´a Martı´nezAgu¨ero1, Hector H. Palacios2, Kathryn Fischbach3, Mark E. Obrenovich4, Joseph C. LaManna5, Valentin Bragin6, Ludis Morales1, 1Pontificia Universidad Javeriana, Bogota´, Colombia; 2Department of Infectious Diseases, Medicine University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; 3The University of Texas at San Antonio, San Antonio, TX, USA; 4Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; 5Department of Physiology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; 6Stress Relief Center, Brooklyn, NY, USA. Contact e-mail:
[email protected] Background: One of the biggest problems and challenges in the development of new drugs and/or treatment strategies for AD is the difficulty of passing the drugs across the blood brain barrier (BBB). The use of nanoparticles in drug delivery therapy holds much promise in targeting remote tissues. The object of the proposed study is to illuminate how injection of silver nanoparticles in the brain lead to leaking on the BBB, and therefore elucidate the possibility of penetrating into the areas of the brain which are most damaged by AD. Methods: We investigated the ultrastructural distribution of nanoparticles (silver ion, 5 nm) in the rat brain hippocampal tissue one and four days after the intra-peritoneal (i.p.) injection. At the end of the experiment perfusion fixation brain tissue was collected for the future electron microscopic analysis. Results: Control animals which received vehicle injection revealed typical ultrastructural morphology of brain microvessels and neurons as we described earlier. The animals that received nanoparticle injection
showed different degrees of brain lesions after one and especially after four days. The vascular and neuronal damage correlates with the presence of nanoparticles in hippocampal tissue. After one and four days of silver injection, varying sizes of silver aggregates were seen throughout the neuronal cell bodies. The accumulation of the silver particles was also associated with the extracellular matrix, which was observed to coexist in the presence of a flake-like structure surrounding the neuronal tissue after four days of silver injection, and appeared to be a permanent feature of the hippocampal tissue. Conclusions: Our study indicates for the first time that i.p. injected silver nanoparticles are definitely able to cross the BBB and can penetrate into the cell cytoplasm and induce underlying cellular changes, which can be used for drug delivery. Further research in this area should include more specific cellular and subcellular mechanisms such as targeting mitochondria, which appears to be a main target for the cell viability, and therefore a prime target for selective treatment strategies. P2-218
CONCENTRATION OF DONEPEZIL TO THERAPEUTIC RESPONSE IN ALZHEIMER’S DISEASE
Yuan-Han Yang1, Su-Hwei Chen2, Mei-Chuan Chou1, Chiou-Lian Lai1, Ching-Kuan Liu1, 1Department of Neurology, Kaohsiung Medical University, Kaohsiung, Taiwan; 2Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan. Contact e-mail:
[email protected] Background: Donepezil, one of the cholinesterase inhibitors, is currently considering the main therapeutic agent to Alzheimer’s disease (AD). However, about 40% of AD patients who do not respond well to such medicine. Meanwhile, increasingly taking higher dose of donepezil has been announced in recent donepezil trials, but we do not know whether taking higher dose of donepezil will benefit AD patients and what the relationships, if any, between plasma concentration of donepezil and therapeutic outcomes. Methods: Newly diagnosed AD patients taking donepezil 5 mg and receiving a series of neuropsychological assessments, including mini-mental status examination (MMSE) and clinical dementia rating (CDR) scale every 6 month were recruited from Alzheimer’s disease research center at Kaohsiung Medical University, a medical center in southern Taiwan. Diagnosis of AD was made according to DSM-IV criteria. The good response of donepezil therapy was regarded as individual’s second MMSE score was the same or higher than his first one, and vice versa in poor response. Blood sample was obtained for Apolipoprotein E4 (ApoE4) genotype and for measurement of donepezil plasma concentration by capillary electrophoresis with Beckman P/ACE MDQ system (Fullerton, CA, USA). Logistic regression analysis was conducted in this study. Results: Eighty-one newly diagnosed mild AD patients taking donepezil 5 mg per day were recruited. Sixty percents of these AD patients were considered good response group with their donepezil concentration: 53.746 31.30 ng/mL (mean 6 SD) at the steady state in contrast to the poor response group with the concentration: 61.98 633.44 ng/ mL. After adjusting other co-variables, we found that the initial MMSE score [p¼0.002, odds ratio (OR)¼1.346, 95%CI¼1.111-1.630] and donepezil plasma concentration (p¼0.023, OR¼1.024, 95%CI¼1.003-1.045) were independently associated with the therapeutic response, not ApoE4 genotype (p¼0.172), age (p¼0.209), education (p¼0.083), and gender (p¼0.359). Conclusions: Higher plasma concentration of donepezil is not associated with the improved cognitive function in AD patient. Adequate dose of donepezil to AD patient could be monitored objectively. P2-219
RESTORATIVE EFFECTS OF BDNF GENE DELIVERY INTO ENTORHINAL CORTEX IN APP TRANSGENIC MICE
Alan H. Nagahara1, Brock E. Schroeder1, Giovanni Coppola2, Ling Wang1, Armin Blesch1, Edward Rockenstein1, Daniel Geschwind2, Eliezer Masliah1, Edward H. Koo1, Mark H. Tuszynski1, 1University of California San Diego, La Jolla, CA, USA; 2University of California Los Angeles, Los Angeles, CA, USA. Contact e-mail:
[email protected] Background: Profound neuronal dysfunction and synapse loss in the entorhinal cortex and hippocampus lead to early impairment of short-term
