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Curcumin derivatives for amyloid detection using 19F magnetic resonance imaging
Poster Presentations P2
P2-013
CURCUMIN DERIVATIVES FOR AMYLOID DETECTION USING 19F MAGNETIC RESONANCE IMAGING
Hiroyasu Taguchi1, Daijiro Yanagisawa1, Shigehiro Morikawa1, Akihiko Shiino1, Toshiro Inubushi1, Koichi Hirao2, Nobuaki Shirai2, Ikuo Tooyama1, 1Shiga University of Medical Science, Otsu, Japan; 2 Industrial Research Center of Shiga Prefecture, Ritto, Japan. Background: Higuchi and colleagues reported an imaging method using 19F magnetic resonance imaging (MRI) with FSB, which allowed the detection of Aß plaques in AD model mice (Nat Neurosci 8:527, 2005). Although the sensitivity of FSB was very low, this finding indicated that 19FMRI could be a promising tool for the detection of Aß deposition. Recently, we have developed a novel 19F-containing curcumin derivative, FMeC1 as a potential imaging agent (Biomaterials 31:4179, 2010). This study investigated whether FMeC1 is suitable as a 19F-MRI probe to detect Aß deposition in the Tg2576 mouse, a model of AD. Methods: FMeC1 solution was prepared at 10 mg/mL in saline containing 10% Tween 80 immediately before use. Mice were anesthetized with sodium pentobarbital (50mg/kg, i.p.). Subsequently, FMeC1 at a dose of 50 - 200 mg/kg was administered via the tail vein. For imaging, we used a 7.0 T horizontal-bore MR scanner (Unity Inova; Varian). A home-built circular-type surface coil measuring 1.6 cm in diameter and tuned to both the 1H and 19F frequencies (300 MHz and 282 MHz, respectively) was used to collect the data. The total acquisition time for one data set was 50 min. Results: 19F-MRI displayed remarkable levels of 19F signal in the brain of Tg2576 mice at 4 hours after the injection of FMeC1. While no signals were detected in the brain of wild-type mice. Histological analysis showed penetration of the compound across the bloodbrain barrier and binding to Aß plaques in peripherally injected Tg2576 mice. The distribution of Aß deposits in Tg2576 mice was in accordance with the region of the brain in which the 19F signal was imaged. Conclusions: These findings suggest the usefulness of FMeC1 as a 19F-MRI probe for the detection of amyloid deposition in the brain. P2-014
IN VITRO STUDY ON PITTSBURGH COMPOUND-B (PIB) BINDING TO BRAIN AMYLOID PLAQUES IN MOUSE MODELS OFALZHEIMER’S DISEASE (AD)
Zhizhen Zeng, Tsing-Bau Chen, Brett Connolly, Patricia Miller, Stacey O’Malley, Guoxin Wu, Eric Hostetler, Cyrille Sur, Mary Savage, Merck Research Laboratories, West Point, Pennsylvania, United States. Background: Alzheimer’s disease (AD) is the most common cause of dementia in people over age 65. Two main lesions found in AD brains, senile plaques (SPs) and neurofibrilary tangles (NFTs), are pathological hallmarks of AD, and consist of amyloid beta (A-beta) and tau, respectively. One approach of Disease-Modifying treatment of AD is by targeting brain A-beta, which is supported by the finding that A-beta is toxic to neurons. The PET tracer [11C]PIB has been used for imaging amyloid plaques in human AD brain, but shows poor binding to amyloid plaques in animal brains of several animal models of AD, indicating different binding properties of brain amyloid plaques to PIB in those animal models of AD. Methods: Mouse models of AD bearing familial AD (FAD) mutations were used in the study, including transgenic model APPswe, and gene-targeted model APPswe/PS1(P264L), which carries human APP containing Swedish FAD mutations, and the mutant pressenilin-1 (PS-1) expression under the control of the normal PS-1 gene. Autoradiography was performed using frozen brain slices and [3H] PIB. Immunohistochemistry (IHC) was done using adjacent slices and antibodies (6E10 and pE3A-beta, pyroglutamate-modified, N-terminal 3cleaved A-beta) for staining amyloid plaques. Results: Brain slices from 7-month old APPswe/PS1(P264L) mice show little [3H]PIB binding, similar to those from age matched control wild type (WT) mice. Lack of specific [3H]PIB binding in these mouse brain slices is consistent with negative staining of amyloid plaques by IHC with 6E10 antibody in the adjacent sections. In contrast, brain slices from 15-month old APPswe/PS1(P264L) mice show positive[3H]PIB binding to amyloid plaques in cerebral cortex and hippocampus, consistent with positive IHC staining of amyloid plaques in the adjacent slices. However, brain slices from age matched control WT mice show
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little [3H]PIB binding and negative IHC staining of amyloid plaques. Similar to previous report, [3H]PIB exhibits minimal binding in brain slices of aged APPswe mice, though dense amyloid plaques are shown in the adjacent brain slices by IHC. Conclusions: The study demonstrates PIB binds to amyloid plaques in APPswe/PS1(P264L) mouse brain slices. The data support further investigation on in vivo PIB binding in this mouse model of AD. P2-015
THE GAMMA-SECRETASE INHIBITOR BMS708163 CAUSES DOSE-DEPENDENT REDUCTIONS IN CSF Ab40 LEVELS IN PATIENTS WITH MILDTO-MODERATE ALZHEIMER’S DISEASE (AD)
Charles Albright1, Niels Andreasen2, Lennart Minthon3, Kaj Blennow4, Howard Feldman1, Holly Soares1, Flora Berisha5, Paul Rhyne6, Linda Rollin1, Vlad Coric1, Robert Berman1, 1Bristol-Myers Squibb, Wallingford, Connecticut, United States; 2Karolinska Universitetssjukhuset Huddinge, Stockholm, Sweden; 3Universitetssjukhuset MAS, Malmo, Sweden; 4University of Goteborg, Sahlgrenska University Hospital, M€olndal, Sweden; 5Bristol-Myers Squibb, Lawrenceville, New Jersey, United States; 6Bristol-Myers Squibb, Princeton, New Jersey, United States. Background: Gamma-secretase produces several ß-amyloid (Aß) species that accumulate in the AD brain, making this enzyme a prime target for Aß-lowering strategies. BMS-708163 is an oral gamma-secretase inhibitor (GSI) designed for the selective inhibition of Aß production. Phase 1 studies showed that BMS-708163 caused a dose-dependent reduction in CSF Aß40 and Aß42 levels at 50 mg/day in healthy individuals. In a separate study, BMS-708163 caused a dose-dependent increase in CSF Aß1-14, 1-15 and 1-16 levels in mild-to-moderate AD patients, indicating increased alphasecretase cleavage of Aß. The current study evaluated the effects of BMS708163 on CSF Aß38, Aß40, Aß42, tau, and p-tau levels in AD patients. Methods: CN156013 was a randomized, double-blind, placebo-controlled, 24-week phase 2 trial designed to assess the safety and tolerability of BMS708163 in patients with mild-to-moderate AD. Secondary analyses included an evaluation of the pharmacodynamic (PD) effects of BMS-708163 on CSF biomarkers. CSF at trough was collected in a subset of patients (n ¼ 10-13/ group) at baseline, week 12, and week 24. Levels of Aß38 (not reported), Aß40, and Aß42 were measured using assays from Mesoscale Discovery and levels of tau and p-tau were measured using the AlzBio3 assay from Innogenetics. Results: BMS-708163 caused dose-dependent decreases in trough CSF Aß40 levels. Compared with placebo, statistically significant reductions in trough CSF Aß40 levels were observed at 100 mg/day (25%) and 125 mg/day (45%). A comparison to phase 1 data showed that BMS-708163 caused similar PD effects on trough CSF Aß40 levels in healthy individuals and AD patients. Based on these data, peak CSF Aß40 levels were estimated to be lowered 10% at 25 mg/day and 20-25% at 50 mg/day. The overall pattern of trough CSF Aß42 levels was similar to that of CSF Aß40. However, the variability in changes of CSF Aß42 was much greater due to assay variability and disease-related changes. We also observed non-statistically significant reductions in mean CSF tau and p-tau of w10-20% at 50 mg/day. Conclusions: The Aß biomarker results provide evidence that BMS708163 engages its target in a dose-dependent manner and is a centrally active GSI in mild-to-moderate patients with AD at all doses tested. P2-016
PERIPHERAL BLOOD GENE EXPRESSION CORRELATES OF CORTICAL ATROPHY ACROSS COGNITIVELY NORMAL ELDERLY AND MCI
Liana Apostolova1, Kristy Hwang1, Giovanni Copolla1, Jessica Lane1, Fying Gao1, Jeffrey Cummings2, Paul Thompson1, 1UCLA, Los Angeles, California, United States; 2Lou Ruvo Institute, Las Vegas, Nevada, United States. Background: Human genome-wide gene expression studies have generated important knowledge about the unique influences of multiple genes in health and disease. The complex interactions between gene expression and imaging biomarkers in Alzheimer’s disease (AD) and the at-risk state of mild cognitive impairment (MCI) may yield important insights about the genetic influences and pathogenesis of AD. Methods: We collected peripheral blood and 1.5T 3D MPRAGE T1-weighted brain MRI data from 38
P2-013
CURCUMIN DERIVATIVES FOR AMYLOID DETECTION USING 19F MAGNETIC RESONANCE IMAGING
Hiroyasu Taguchi1, Daijiro Yanagisawa1, Shigehiro Morikawa1, Akihiko Shiino1, Toshiro Inubushi1, Koichi Hirao2, Nobuaki Shirai2, Ikuo Tooyama1, 1Shiga University of Medical Science, Otsu, Japan; 2 Industrial Research Center of Shiga Prefecture, Ritto, Japan. Background: Higuchi and colleagues reported an imaging method using 19F magnetic resonance imaging (MRI) with FSB, which allowed the detection of Aß plaques in AD model mice (Nat Neurosci 8:527, 2005). Although the sensitivity of FSB was very low, this finding indicated that 19FMRI could be a promising tool for the detection of Aß deposition. Recently, we have developed a novel 19F-containing curcumin derivative, FMeC1 as a potential imaging agent (Biomaterials 31:4179, 2010). This study investigated whether FMeC1 is suitable as a 19F-MRI probe to detect Aß deposition in the Tg2576 mouse, a model of AD. Methods: FMeC1 solution was prepared at 10 mg/mL in saline containing 10% Tween 80 immediately before use. Mice were anesthetized with sodium pentobarbital (50mg/kg, i.p.). Subsequently, FMeC1 at a dose of 50 - 200 mg/kg was administered via the tail vein. For imaging, we used a 7.0 T horizontal-bore MR scanner (Unity Inova; Varian). A home-built circular-type surface coil measuring 1.6 cm in diameter and tuned to both the 1H and 19F frequencies (300 MHz and 282 MHz, respectively) was used to collect the data. The total acquisition time for one data set was 50 min. Results: 19F-MRI displayed remarkable levels of 19F signal in the brain of Tg2576 mice at 4 hours after the injection of FMeC1. While no signals were detected in the brain of wild-type mice. Histological analysis showed penetration of the compound across the bloodbrain barrier and binding to Aß plaques in peripherally injected Tg2576 mice. The distribution of Aß deposits in Tg2576 mice was in accordance with the region of the brain in which the 19F signal was imaged. Conclusions: These findings suggest the usefulness of FMeC1 as a 19F-MRI probe for the detection of amyloid deposition in the brain. P2-014
IN VITRO STUDY ON PITTSBURGH COMPOUND-B (PIB) BINDING TO BRAIN AMYLOID PLAQUES IN MOUSE MODELS OFALZHEIMER’S DISEASE (AD)
Zhizhen Zeng, Tsing-Bau Chen, Brett Connolly, Patricia Miller, Stacey O’Malley, Guoxin Wu, Eric Hostetler, Cyrille Sur, Mary Savage, Merck Research Laboratories, West Point, Pennsylvania, United States. Background: Alzheimer’s disease (AD) is the most common cause of dementia in people over age 65. Two main lesions found in AD brains, senile plaques (SPs) and neurofibrilary tangles (NFTs), are pathological hallmarks of AD, and consist of amyloid beta (A-beta) and tau, respectively. One approach of Disease-Modifying treatment of AD is by targeting brain A-beta, which is supported by the finding that A-beta is toxic to neurons. The PET tracer [11C]PIB has been used for imaging amyloid plaques in human AD brain, but shows poor binding to amyloid plaques in animal brains of several animal models of AD, indicating different binding properties of brain amyloid plaques to PIB in those animal models of AD. Methods: Mouse models of AD bearing familial AD (FAD) mutations were used in the study, including transgenic model APPswe, and gene-targeted model APPswe/PS1(P264L), which carries human APP containing Swedish FAD mutations, and the mutant pressenilin-1 (PS-1) expression under the control of the normal PS-1 gene. Autoradiography was performed using frozen brain slices and [3H] PIB. Immunohistochemistry (IHC) was done using adjacent slices and antibodies (6E10 and pE3A-beta, pyroglutamate-modified, N-terminal 3cleaved A-beta) for staining amyloid plaques. Results: Brain slices from 7-month old APPswe/PS1(P264L) mice show little [3H]PIB binding, similar to those from age matched control wild type (WT) mice. Lack of specific [3H]PIB binding in these mouse brain slices is consistent with negative staining of amyloid plaques by IHC with 6E10 antibody in the adjacent sections. In contrast, brain slices from 15-month old APPswe/PS1(P264L) mice show positive[3H]PIB binding to amyloid plaques in cerebral cortex and hippocampus, consistent with positive IHC staining of amyloid plaques in the adjacent slices. However, brain slices from age matched control WT mice show
S311
little [3H]PIB binding and negative IHC staining of amyloid plaques. Similar to previous report, [3H]PIB exhibits minimal binding in brain slices of aged APPswe mice, though dense amyloid plaques are shown in the adjacent brain slices by IHC. Conclusions: The study demonstrates PIB binds to amyloid plaques in APPswe/PS1(P264L) mouse brain slices. The data support further investigation on in vivo PIB binding in this mouse model of AD. P2-015
THE GAMMA-SECRETASE INHIBITOR BMS708163 CAUSES DOSE-DEPENDENT REDUCTIONS IN CSF Ab40 LEVELS IN PATIENTS WITH MILDTO-MODERATE ALZHEIMER’S DISEASE (AD)
Charles Albright1, Niels Andreasen2, Lennart Minthon3, Kaj Blennow4, Howard Feldman1, Holly Soares1, Flora Berisha5, Paul Rhyne6, Linda Rollin1, Vlad Coric1, Robert Berman1, 1Bristol-Myers Squibb, Wallingford, Connecticut, United States; 2Karolinska Universitetssjukhuset Huddinge, Stockholm, Sweden; 3Universitetssjukhuset MAS, Malmo, Sweden; 4University of Goteborg, Sahlgrenska University Hospital, M€olndal, Sweden; 5Bristol-Myers Squibb, Lawrenceville, New Jersey, United States; 6Bristol-Myers Squibb, Princeton, New Jersey, United States. Background: Gamma-secretase produces several ß-amyloid (Aß) species that accumulate in the AD brain, making this enzyme a prime target for Aß-lowering strategies. BMS-708163 is an oral gamma-secretase inhibitor (GSI) designed for the selective inhibition of Aß production. Phase 1 studies showed that BMS-708163 caused a dose-dependent reduction in CSF Aß40 and Aß42 levels at 50 mg/day in healthy individuals. In a separate study, BMS-708163 caused a dose-dependent increase in CSF Aß1-14, 1-15 and 1-16 levels in mild-to-moderate AD patients, indicating increased alphasecretase cleavage of Aß. The current study evaluated the effects of BMS708163 on CSF Aß38, Aß40, Aß42, tau, and p-tau levels in AD patients. Methods: CN156013 was a randomized, double-blind, placebo-controlled, 24-week phase 2 trial designed to assess the safety and tolerability of BMS708163 in patients with mild-to-moderate AD. Secondary analyses included an evaluation of the pharmacodynamic (PD) effects of BMS-708163 on CSF biomarkers. CSF at trough was collected in a subset of patients (n ¼ 10-13/ group) at baseline, week 12, and week 24. Levels of Aß38 (not reported), Aß40, and Aß42 were measured using assays from Mesoscale Discovery and levels of tau and p-tau were measured using the AlzBio3 assay from Innogenetics. Results: BMS-708163 caused dose-dependent decreases in trough CSF Aß40 levels. Compared with placebo, statistically significant reductions in trough CSF Aß40 levels were observed at 100 mg/day (25%) and 125 mg/day (45%). A comparison to phase 1 data showed that BMS-708163 caused similar PD effects on trough CSF Aß40 levels in healthy individuals and AD patients. Based on these data, peak CSF Aß40 levels were estimated to be lowered 10% at 25 mg/day and 20-25% at 50 mg/day. The overall pattern of trough CSF Aß42 levels was similar to that of CSF Aß40. However, the variability in changes of CSF Aß42 was much greater due to assay variability and disease-related changes. We also observed non-statistically significant reductions in mean CSF tau and p-tau of w10-20% at 50 mg/day. Conclusions: The Aß biomarker results provide evidence that BMS708163 engages its target in a dose-dependent manner and is a centrally active GSI in mild-to-moderate patients with AD at all doses tested. P2-016
PERIPHERAL BLOOD GENE EXPRESSION CORRELATES OF CORTICAL ATROPHY ACROSS COGNITIVELY NORMAL ELDERLY AND MCI
Liana Apostolova1, Kristy Hwang1, Giovanni Copolla1, Jessica Lane1, Fying Gao1, Jeffrey Cummings2, Paul Thompson1, 1UCLA, Los Angeles, California, United States; 2Lou Ruvo Institute, Las Vegas, Nevada, United States. Background: Human genome-wide gene expression studies have generated important knowledge about the unique influences of multiple genes in health and disease. The complex interactions between gene expression and imaging biomarkers in Alzheimer’s disease (AD) and the at-risk state of mild cognitive impairment (MCI) may yield important insights about the genetic influences and pathogenesis of AD. Methods: We collected peripheral blood and 1.5T 3D MPRAGE T1-weighted brain MRI data from 38