- Email: [email protected]
GENETIC ANALYSIS OF THE STEROIDOGENESIS PATHWAY: ASSOCIATIONS WITH ALZHEIMER'S DISEASE RISK AND RELATED PHENOTYPES
Poster Presentations: P3 proteins was quantitated using a l abel-free protein quantification method, and these were competed with the concentrations of A b42, pTau181, and tTau. Results: The MMSE score in AD patients was 21.3 6 4.9, and the average CDR scores were 0.8 6 0.3. All of the CSF samples were sufficient to establish the diagnostic cut-off value of the Ab42/pTau181 and Ab42/ tTau ratios in our laboratory.Fifteen of the 724 protein samples demonstrated a significant correlation with at least one of the AD biomarkers (p < 0.05). Seven of these proteins were previously identified as AD biomarkers, whereas eight were newly found. T he direction of change in the levels of Ab42 was found to be opposite to those of the levels of the Tau proteins in all analytes. Regarding the Ab42 levels, four proteins revealed a significant correlation. Another four proteins demonstrated a significant correlation with both pTau181 and tTau concentrations. We found three proteins to have a significant relationship only with pTau181, whereas two proteins showed a significant correlation only with tTau levels. Interestingly, t here were no analytes that demonstrated a correlation with both Ab42 and Tau proteins simultaneously. The remaining proteins showed a distinct correlation with the combined ratio of Ab42/ pTau181 or Ab42/tTau; however, the relationship with the individual concentrations was statistically negligible. Conclusions: Through our work, we identified new candidate CSF biomarkers of AD. Considering their biological roles, these candidate markers are suggested to be intimately related to AD pathophysiology. Further investigations are needed to identify their values as surrogate biomarkers or therapeutic targets in AD. P3-106
GENETIC ANALYSIS OF THE STEROIDOGENESIS PATHWAY: ASSOCIATIONS WITH ALZHEIMER’S DISEASE RISK AND RELATED PHENOTYPES
Andrea C. Wilson1, Sara Garin1, Tenielle Louise Sandra Porter1, Giuseppe Verdile2, David M. Groth2, Victor L. Villemagne3, David Ames4, Ashley I. Bush5, Kathryn A. Ellis6, Lance Macaulay7, Colin L. Masters8, Stephanie Ruth Rainey-Smith1, Alan Rembach9, Christopher Rowe3, Kevin Taddei10, Ralph N. Martins10, Simon Matthew Laws11, AIBL RESEARCH GROUP12, 1Edith Cowan University, Perth, Australia; 2Curtin University, Perth, Australia; 3Austin Health, Melbourne, Australia; 4 National Ageing Research Institute Inc. (NARI), Parkville, Australia; 5 Florey Institute of Neuroscience & Mental Health, Parkville, Australia; 6St Georges Hospital, Parkville, Australia; 7CSIRO, Parkville, Australia; 8 Florey Institute, UoM, Parkville, Australia; 9Mental Health Research Institute, Melbourne, Australia; 10Edith Cowan University, Joondalup, Australia; 11Edith Cowan University, Perth, Australia; 12Mental Health Research Institute, Perth, Australia. Contact e-mail: tenielle.porter@gmail. com Background: In addition to being the greatest risk factor for Alzheimer’s disease (AD), ageing also results in the deregulation of hormonal homeostasis. The steroidogenesis pathway describes the synthesis of the steroid hormones (progestagens, androgens, estrogens, mineralo- and gluco- corticoids) from cholesterol. Changes in hormone levels, in particular cortisol, testosterone and oestrogen, have been associated with the promotion of neurodegeneration and the aggregation of beta amyloid and tau. This suggests that alterations in steroid synthesis could be associated with an increased risk of developing AD. The study described below aimed to further investigate steroidogenesis with regards to AD. Methods: Through a fine-mapping approach, using tagSNPs (Haploview, r 2 cut-off 0.9), 88 polymorphisms across 15 genes were selected and genotyped within the Australian Imaging, Biomarkers & Lifestyle (AIBL) Study of Aging cohort (1473 samples) and investigated in relation to AD-risk and clinical phenotypes (i.e. neocortical amyloid burden, hippocampal volume and cognitive performance). Variants were also investigated with regards to endogenous hormone levels (i.e. circulating free testosterone (cFT), cortisol, and estradiol). Results: Risk association analyses yielded positive associations between two variants within steroid 5-aplphareductase (SRD5A1; rs518763 & rs248803; increased risk; FDR corrected P value (Q)¼0.045) and one variant within Aldo-keto Reductase family 1, member C3 (AKR1C3; rs4881400; decreased risk; Q¼0.045) and AD in a dominant model. Additionally, in a recessive model a variant (rs6203) in 3-Beta-hydroxysteroid dehydrogenase gene (HSD3B1) was also associated
P667
with increased AD-risk (Q¼0.034). Regression analysis revealed that increased amyloid burden was associated with carrying the minor allele for SRD5A1 rs518763 (P¼0.031), whereas rs248803 within that same gene was associated with decreased hippocampal volume (P¼0.013). Both rs518673 (P¼0.035) and rs248803 (P¼0.044) polymorphisms within SRD5A1 in addition to rs6203 (P¼0.010) in HSD3B1 were associated to poorer cognitive performance on a memory task. Only trends towards associations with measured hormone levels were observed. Conclusions: This project suggests that variations within the steroidogenic pathway modulates the risk towards developing AD and is associated with AD phenotypes. This project is also the first to identify variants within SRD5A1, AKR1C3 and HSD3B1 as having an association with the modulation of AD risk and clinical phenotypes. P3-107
RETINAL IMAGING OF AB DEPOSITS IN AD PATIENTS: FROM HISTOLOGICAL EXAMINATION TO CLINICAL TRIALS
Yosef Koronyo1, David Biggs2, Ernesto Barron3, David R. Hinton4, David S. Boyer5, Dieu-Trang (Sandrine) Fuchs6, Carol A. Miller7, Sally A. Frautschy8, Greg M. Cole8, Steven R. Verdooner9, Keith L. Black1, Maya Koronyo-Hamaoui1, 1Cedars-Sinai Medical Center, Los Angeles, California, United States; 2Neurovision Imaging, LLC, Sacramento, California, United States; 3Doheny Eye Institute, Los Angeles, California, United States; 4Pathology, Neurosurgery, Ophthalmology, Keck School of Medicine, Los Angeles, California, United States; 5Retina Vitreous Associates Medical Group, Los Angeles, California, United States; 6Cedars Sinai Medical Center, Los Angeles, California, United States; 7Keck School of Medicine of USC, Los Angeles, California, United States; 8UCLA and Geriatric Research and Clinical Center, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States; 9 NeuroVision Imaging, LLC, Sacramento, California, United States. Contact e-mail: [email protected] Background: There is an urgent unmet need for noninvasive diagnosis of Alzheimer’s disease (AD) especially at early stages to facilitate prevention or therapeutic intervention. The retina as an extension of the brain can be imaged directly and noninvasively with high resolution and sensitivity. We previously identified hallmark amyloid b-protein (Ab) deposits in postmortem retinas of AD patients and early stage cases. Subsequent studies, found the characteristic brain pathology pTau, Ab-like deposits, and accumulation of Ab 1-42 peptides, in postmortem AD patients’ retina. Methods: To characterize geographical distribution, layer location, and ultrastructural morphology of Ab deposits, we utilized retinal whole mounts and cross sections from MCI, AD patients, and age-matched controls so as to guide the subsequent live imaging protocol. We further translated our noninvasive rodent retinal Ab-plaque imaging approach using curcumin labeling into human trials. Results: Screening of whole mount retinas from MCI and AD patients revealed clusters of abluminal Ab deposits, especially in proximity to blood vessels in the superior and inferior-nasal quadrants. Age-matched controls showed only scarce Ab deposition. In retinal cross sections, Ab deposits were abundant in the innermost layers, and occasionally appeared perivascular and intracellular. Moreover, electron microscopy analysis confirmed the ultrastractural morphology of retinal Ab deposits and fibrils. In pilot clinical trials, we report for the first time the detection of Ab plaques, via curcumin fluorescence, in the retina of live AD patients. A proprietary oral curcumin formulation with high bioavailability and modified scanning confocal ophthalmoscope were utilized. We further developed and optimized a fully automated calculation of a Retinal Amyloid Index (RAI), a quantitative measure of curcumin-labeling amyloid in the retina. Analysis of RAI scores, including Ab plaque number, area and distribution, showed a significant increase in RAI geometric means of AD patients (P ¼ 0.0088), approximately 2.7 times higher than the matched controls. Conclusions: This study demonstrates early accumulation of Ab deposits in AD retina, abundant in the innermost layers and in clusters within distinctive geographical distribution. The feasibility to detect Ab deposits by noninvasive retinal imaging and differentiate between AD patients and controls may present an excellent modality for early diagnosis and monitoring AD therapies.
GENETIC ANALYSIS OF THE STEROIDOGENESIS PATHWAY: ASSOCIATIONS WITH ALZHEIMER’S DISEASE RISK AND RELATED PHENOTYPES
Andrea C. Wilson1, Sara Garin1, Tenielle Louise Sandra Porter1, Giuseppe Verdile2, David M. Groth2, Victor L. Villemagne3, David Ames4, Ashley I. Bush5, Kathryn A. Ellis6, Lance Macaulay7, Colin L. Masters8, Stephanie Ruth Rainey-Smith1, Alan Rembach9, Christopher Rowe3, Kevin Taddei10, Ralph N. Martins10, Simon Matthew Laws11, AIBL RESEARCH GROUP12, 1Edith Cowan University, Perth, Australia; 2Curtin University, Perth, Australia; 3Austin Health, Melbourne, Australia; 4 National Ageing Research Institute Inc. (NARI), Parkville, Australia; 5 Florey Institute of Neuroscience & Mental Health, Parkville, Australia; 6St Georges Hospital, Parkville, Australia; 7CSIRO, Parkville, Australia; 8 Florey Institute, UoM, Parkville, Australia; 9Mental Health Research Institute, Melbourne, Australia; 10Edith Cowan University, Joondalup, Australia; 11Edith Cowan University, Perth, Australia; 12Mental Health Research Institute, Perth, Australia. Contact e-mail: tenielle.porter@gmail. com Background: In addition to being the greatest risk factor for Alzheimer’s disease (AD), ageing also results in the deregulation of hormonal homeostasis. The steroidogenesis pathway describes the synthesis of the steroid hormones (progestagens, androgens, estrogens, mineralo- and gluco- corticoids) from cholesterol. Changes in hormone levels, in particular cortisol, testosterone and oestrogen, have been associated with the promotion of neurodegeneration and the aggregation of beta amyloid and tau. This suggests that alterations in steroid synthesis could be associated with an increased risk of developing AD. The study described below aimed to further investigate steroidogenesis with regards to AD. Methods: Through a fine-mapping approach, using tagSNPs (Haploview, r 2 cut-off 0.9), 88 polymorphisms across 15 genes were selected and genotyped within the Australian Imaging, Biomarkers & Lifestyle (AIBL) Study of Aging cohort (1473 samples) and investigated in relation to AD-risk and clinical phenotypes (i.e. neocortical amyloid burden, hippocampal volume and cognitive performance). Variants were also investigated with regards to endogenous hormone levels (i.e. circulating free testosterone (cFT), cortisol, and estradiol). Results: Risk association analyses yielded positive associations between two variants within steroid 5-aplphareductase (SRD5A1; rs518763 & rs248803; increased risk; FDR corrected P value (Q)¼0.045) and one variant within Aldo-keto Reductase family 1, member C3 (AKR1C3; rs4881400; decreased risk; Q¼0.045) and AD in a dominant model. Additionally, in a recessive model a variant (rs6203) in 3-Beta-hydroxysteroid dehydrogenase gene (HSD3B1) was also associated
P667
with increased AD-risk (Q¼0.034). Regression analysis revealed that increased amyloid burden was associated with carrying the minor allele for SRD5A1 rs518763 (P¼0.031), whereas rs248803 within that same gene was associated with decreased hippocampal volume (P¼0.013). Both rs518673 (P¼0.035) and rs248803 (P¼0.044) polymorphisms within SRD5A1 in addition to rs6203 (P¼0.010) in HSD3B1 were associated to poorer cognitive performance on a memory task. Only trends towards associations with measured hormone levels were observed. Conclusions: This project suggests that variations within the steroidogenic pathway modulates the risk towards developing AD and is associated with AD phenotypes. This project is also the first to identify variants within SRD5A1, AKR1C3 and HSD3B1 as having an association with the modulation of AD risk and clinical phenotypes. P3-107
RETINAL IMAGING OF AB DEPOSITS IN AD PATIENTS: FROM HISTOLOGICAL EXAMINATION TO CLINICAL TRIALS
Yosef Koronyo1, David Biggs2, Ernesto Barron3, David R. Hinton4, David S. Boyer5, Dieu-Trang (Sandrine) Fuchs6, Carol A. Miller7, Sally A. Frautschy8, Greg M. Cole8, Steven R. Verdooner9, Keith L. Black1, Maya Koronyo-Hamaoui1, 1Cedars-Sinai Medical Center, Los Angeles, California, United States; 2Neurovision Imaging, LLC, Sacramento, California, United States; 3Doheny Eye Institute, Los Angeles, California, United States; 4Pathology, Neurosurgery, Ophthalmology, Keck School of Medicine, Los Angeles, California, United States; 5Retina Vitreous Associates Medical Group, Los Angeles, California, United States; 6Cedars Sinai Medical Center, Los Angeles, California, United States; 7Keck School of Medicine of USC, Los Angeles, California, United States; 8UCLA and Geriatric Research and Clinical Center, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, California, United States; 9 NeuroVision Imaging, LLC, Sacramento, California, United States. Contact e-mail: [email protected] Background: There is an urgent unmet need for noninvasive diagnosis of Alzheimer’s disease (AD) especially at early stages to facilitate prevention or therapeutic intervention. The retina as an extension of the brain can be imaged directly and noninvasively with high resolution and sensitivity. We previously identified hallmark amyloid b-protein (Ab) deposits in postmortem retinas of AD patients and early stage cases. Subsequent studies, found the characteristic brain pathology pTau, Ab-like deposits, and accumulation of Ab 1-42 peptides, in postmortem AD patients’ retina. Methods: To characterize geographical distribution, layer location, and ultrastructural morphology of Ab deposits, we utilized retinal whole mounts and cross sections from MCI, AD patients, and age-matched controls so as to guide the subsequent live imaging protocol. We further translated our noninvasive rodent retinal Ab-plaque imaging approach using curcumin labeling into human trials. Results: Screening of whole mount retinas from MCI and AD patients revealed clusters of abluminal Ab deposits, especially in proximity to blood vessels in the superior and inferior-nasal quadrants. Age-matched controls showed only scarce Ab deposition. In retinal cross sections, Ab deposits were abundant in the innermost layers, and occasionally appeared perivascular and intracellular. Moreover, electron microscopy analysis confirmed the ultrastractural morphology of retinal Ab deposits and fibrils. In pilot clinical trials, we report for the first time the detection of Ab plaques, via curcumin fluorescence, in the retina of live AD patients. A proprietary oral curcumin formulation with high bioavailability and modified scanning confocal ophthalmoscope were utilized. We further developed and optimized a fully automated calculation of a Retinal Amyloid Index (RAI), a quantitative measure of curcumin-labeling amyloid in the retina. Analysis of RAI scores, including Ab plaque number, area and distribution, showed a significant increase in RAI geometric means of AD patients (P ¼ 0.0088), approximately 2.7 times higher than the matched controls. Conclusions: This study demonstrates early accumulation of Ab deposits in AD retina, abundant in the innermost layers and in clusters within distinctive geographical distribution. The feasibility to detect Ab deposits by noninvasive retinal imaging and differentiate between AD patients and controls may present an excellent modality for early diagnosis and monitoring AD therapies.