We use cookies to improve your experience. By continuing to browse this site, you accept our cookie policy.×
Skip main navigation
Aging Health
Bioelectronics in Medicine
Biomarkers in Medicine
Breast Cancer Management
CNS Oncology
Colorectal Cancer
Concussion
Epigenomics
Future Cardiology
Future Medicine AI
Future Microbiology
Future Neurology
Future Oncology
Future Rare Diseases
Future Virology
Hepatic Oncology
HIV Therapy
Immunotherapy
International Journal of Endocrine Oncology
International Journal of Hematologic Oncology
Journal of 3D Printing in Medicine
Lung Cancer Management
Melanoma Management
Nanomedicine
Neurodegenerative Disease Management
Pain Management
Pediatric Health
Personalized Medicine
Pharmacogenomics
Regenerative Medicine

Clearing the amyloid in Alzheimer's: progress towards earlier diagnosis and effective treatments – an update for clinicians

    Prita R Asih

    Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA 6027, Australia

    Separation Science & Metabolomics Laboratory, Murdoch University, Murdoch, WA 6150, Australia

    Authors contributed equally

    Search for more papers by this author

    ,
    Pratishtha Chatterjee

    Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA 6027, Australia

    School of Psychiatry & Clinical Neurosciences, University of Western Australia, Crawley, WA 6009, Australia

    The Cooperative Research Centre for Mental Health, Australia

    Authors contributed equally

    Search for more papers by this author

    ,
    Giuseppe Verdile

    Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA 6027, Australia

    School of Psychiatry & Clinical Neurosciences, University of Western Australia, Crawley, WA 6009, Australia

    School of Biomedical Sciences, Curtin University, Bentley, WA 6102, Australia

    ,
    Veer B Gupta

    Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA 6027, Australia

    The Cooperative Research Centre for Mental Health, Australia

    ,
    Robert D Trengove

    Separation Science & Metabolomics Laboratory, Murdoch University, Murdoch, WA 6150, Australia

    &
    Ralph N Martins

    *Author for correspondence:

    E-mail Address: r.martins@ecu.edu.au

    Centre of Excellence for Alzheimer's Disease Research & Care, School of Medical Sciences, Edith Cowan University, Joondalup, WA 6027, Australia

    School of Psychiatry & Clinical Neurosciences, University of Western Australia, Crawley, WA 6009, Australia

    The Cooperative Research Centre for Mental Health, Australia

    Published Online:https://doi.org/10.2217/nmt.14.29

    SUMMARY 

    A beta (Aβ or β-amyloid) is a key molecule in Alzheimer's disease (AD) pathogenesis. According to the ‘amyloid hypothesis’, the gradual accumulation of Aβ triggers events which results in neuronal loss in regions of the brain involved with memory and learning. Diverse agents have been developed to reduce brain Aβ accumulation or to enhance its clearance. Some have progressed to human trials, however all have failed to improve cognition in patients. This has led researchers to question whether Aβ is really the problem. However, the trials have been targeting end stages of AD, by which stage extensive irreversible neuronal damage has already occurred. Intervention is required preclinically, therefore preclinical AD biomarkers are needed. In this regard, amyloid imaging and cerebrospinal fluid biomarkers are leading the way, with plasma biomarkers and eye tests also being investigated. This review covers the current state of knowledge of Aβ as an early diagnostic biomarker and as a therapeutic target in AD.

    References

    • 1 Brookmeyer R, Johnson E, Ziegler-Graham K, Arrighi HM. Forecasting the global burden of Alzheimer's disease. Alzheimer Dementia 3(3), 186–191 (2007).
    • 2 Whiley L, Sen A, Heaton J et al. Evidence of altered phosphatidylcholine metabolism in Alzheimer's disease. Neurobiol. Aging 35(2), 271–278 (2014).
    • 3 Drolle E, Hane F, Lee B, Leonenko Z. Atomic force microscopy to study molecular mechanisms of amyloid fibril formation and toxicity in Alzheimer's disease. Drug Metabol. Rev. 46(2), 207–223 (2014).
    • 4 Jarrett JT, Berger EP, Lansbury PT Jr. The carboxy terminus of the beta amyloid protein is critical for the seeding of amyloid formation: implications for the pathogenesis of Alzheimer's disease. Biochemistry 32(18), 4693–4697 (1993).
    • 5 Dong S, Duan Y, Hu Y, Zhao Z. Advances in the pathogenesis of Alzheimer's disease: a re-evaluation of amyloid cascade hypothesis. Transl. Neurodegen. 1(1), 18 (2012).
    • 6 Bornebroek M, Haan J, Maat-Schieman ML, Van Duinen SG, Roos RA. Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D): I – A review of clinical, radiologic and genetic aspects. Brain Pathol. 6(2), 111–114 (1996).
    • 7 Kumar-Singh S. Cerebral amyloid angiopathy: pathogenetic mechanisms and link to dense amyloid plaques. Genes Brain Behav. 7(Suppl. 1), 67–82 (2008).
    • 8 Weller RO, Massey A, Newman TA, Hutchings M, Kuo YM, Roher AE. Cerebral amyloid angiopathy: amyloid beta accumulates in putative interstitial fluid drainage pathways in Alzheimer's disease. Am. J. Pathol. 153(3), 725–733 (1998).
    • 9 Yamada M, Naiki H. Cerebral amyloid angiopathy. Prog. Mol. Biol. Translat. Sci. 107, 41–78 (2012).
    • 10 Ittner LM, Gotz J. Amyloid-beta and tau – a toxic pas de deux in Alzheimer's disease. Nat. Rev. Neurosci. 12(2), 65–72 (2011).
    • 11 Sorrentino G Bonavita V. Neurodegeneration and Alzheimer's disease: the lesson from tauopathies. Neurol. Sci. 28(2), 63–71 (2007).
    • 12 Stern Y. Cognitive reserve in ageing and Alzheimer's disease. Lancet Neurol 11(11), 1006–1012 (2012).
    • 13 Wilson RS, Boyle PA, Yu L, Barnes LL, Schneider JA, Bennett DA. Life-span cognitive activity, neuropathologic burden, and cognitive aging. Neurology 81(4), 314–321 (2013).
    • 14 Tanzi RE. A brief history of Alzheimer's disease gene discovery. J. Alzheimers Dis. 33(Suppl. 1), S5–S13 (2013).
    • 15 Jonsson T, Atwal JK, Steinberg S et al. A mutation in APP protects against Alzheimer's disease and age-related cognitive decline. Nature 488(7409), 96–99 (2012).
    • 16 Mawuenyega KG, Sigurdson W, Ovod V et al. Decreased clearance of CNS beta-amyloid in Alzheimer's disease. Science 330(6012), 1774 (2010).
    • 17 Bates KA, Verdile G, Li QX et al. Clearance mechanisms of Alzheimer's amyloid-beta peptide: implications for therapeutic design and diagnostic tests. Mol. Psychiatry 14(5), 469–486 (2009).
    • 18 Miners JS, Barua N, Kehoe PG, Gill S, Love S. Abeta-degrading enzymes: potential for treatment of Alzheimer disease. J. Neuropathol. Exp. Neurol. 70(11), 944–959 (2011).
    • 19 Sharman MJ, Morici M, Hone E et al. APOE genotype results in differential effects on the peripheral clearance of amyloid-beta42 in APOE knock-in and knock-out mice. J. Alzheimers Dis. 21(2), 403–409 (2010).
    • 20 Morris JC, Roe CM, Xiong C et al. APOE predicts amyloid-beta but not tau Alzheimer pathology in cognitively normal aging. Ann. Neurol. 67(1), 122–131 (2010).
    • 21 Miners JS, Jones R, Love S. Differential changes in Abeta42 and Abeta40 with age. J. Alzheimers Dis. 40(3), 727–735 (2014).
    • 22 Reddy PH, Beal MF. Amyloid beta, mitochondrial dysfunction and synaptic damage: implications for cognitive decline in aging and Alzheimer's disease. Trends Mol. Med. 14(2), 45–53 (2008).
    • 23 Aizenstein HJ, Nebes RD, Saxton JA et al. Frequent amyloid deposition without significant cognitive impairment among the elderly. Arch. Neurol. 65(11), 1509–1517 (2008).
    • 24 Holtzman DM, Herz J, Bu G. Apolipoprotein E and apolipoprotein E receptors: normal biology and roles in Alzheimer disease. Cold Spring Harbor Persp. Med. 2(3), a006312 (2012).
    • 25 Deane R, Bell RD, Sagare A, Zlokovic BV. Clearance of amyloid-beta peptide across the blood-brain barrier: implication for therapies in Alzheimer's disease. CNS Neurol. Dis. Drug Target 8(1), 16–30 (2009).
    • 26 Liu CC, Kanekiyo T, Xu H, Bu G. Apolipoprotein E and Alzheimer disease: risk, mechanisms and therapy. Nat. Rev. Neurol. 9(2), 106–118 (2013).
    • 27 Yang DS, Small DH, Seydel U et al. Apolipoprotein E promotes the binding and uptake of beta-amyloid into Chinese hamster ovary cells in an isoform-specific manner. Neuroscience 90(4), 1217–1226 (1999).
    • 28 Tai LM, Mehra S, Shete V et al. Soluble apoE/Abeta complex: mechanism and therapeutic target for APOE4-induced AD risk. Mol. Neurodegen. 9, 2 (2014).
    • 29 Luchsinger JA. Diabetes, related conditions, and dementia. J. Neurol. Sci. 299(1–2), 35–38 (2010).
    • 30 Dash SK. Cognitive impairment and diabetes. Recent Patent Endocr. Metabol. Immune Drug Discov. 7(2), 155–165 (2013).
    • 31 De La Monte SM. Relationships Between Diabetes and Cognitive Impairment. Endocrinol. Metab. Clin. North Am. 43(1), 245–267 (2014).
    • 32 Xu W, Qiu C, Gatz M, Pedersen NL, Johansson B, Fratiglioni L. Mid- and late-life diabetes in relation to the risk of dementia: a population-based twin study. Diabetes 58(1), 71–77 (2009).
    • 33 Strachan MW, Reynolds RM, Frier BM, Mitchell RJ, Price JF. The relationship between Type 2 diabetes and dementia. Br. Med. Bull. 88(1), 131–146 (2008).
    • 34 Zhao WQ, De Felice FG, Fernandez S et al. Amyloid beta oligomers induce impairment of neuronal insulin receptors. FASEB J. 22(1), 246–260 (2008).
    • 35 Bomfim TR, Forny-Germano L, Sathler LB et al. An anti-diabetes agent protects the mouse brain from defective insulin signaling caused by Alzheimer's disease-associated Abeta oligomers. J. Clin. Invest. 122(4), 1339–1353 (2012).
    • 36 Papadopoulos P, Rosa-Neto P, Rochford J, Hamel E. Pioglitazone improves reversal learning and exerts mixed cerebrovascular effects in a mouse model of Alzheimer's disease with combined amyloid-beta and cerebrovascular pathology. PLoS ONE 8(7), e68612 (2013).
    • 37 Freiherr J, Hallschmid M, Frey WH, 2nd et al. Intranasal insulin as a treatment for Alzheimer's disease: a review of basic research and clinical evidence. CNS Drugs 27(7), 505–514 (2013).
    • 38 Brown BM, Peiffer JJ, Sohrabi HR et al. Intense physical activity is associated with cognitive performance in the elderly. Translat. Psychiatr. 2, e191 (2012).
    • 39 Lautenschlager NT, Cox KL, Flicker L et al. Effect of physical activity on cognitive function in older adults at risk for Alzheimer disease: a randomized trial. JAMA 300(9), 1027–1037 (2008).
    • 40 Hu N, Yu JT, Tan L, Wang YL, Sun L, Tan L. Nutrition and the risk of Alzheimer's disease. BioMed Res. Int. 524820 (2013).
    • 41 Solfrizzi V, Panza F, Frisardi V et al. Diet and Alzheimer's disease risk factors or prevention: the current evidence. Expert Rev. Neurother. 11(5), 677–708 (2011).
    • 42 Strozyk D, Blennow K, White LR, Launer LJ. CSF Abeta 42 levels correlate with amyloid-neuropathology in a population-based autopsy study. Neurology 60(4), 652–656 (2003).
    • 43 Moreth J, Mavoungou C, Schindowski K. Is abeta a sufficient biomarker for monitoring anti-abeta clinical studies? A critical review. Front. Aging Neurosci. 5, 25 (2013).
    • 44 Henry MS, Passmore AP, Todd S, Mcguinness B, Craig D, Johnston JA. The development of effective biomarkers for Alzheimer's disease: a review. Int. J. Geriatr. Psychiatr. 28(4), 331–340 (2013).
    • 45 Biagioni MC, Galvin JE. Using biomarkers to improve detection of Alzheimer's disease. Neurodegen. Dis. Manage. 1(2), 127–139 (2011).
    • 46 Rosen C, Hansson O, Blennow K, Zetterberg H. Fluid biomarkers in Alzheimer's disease – current concepts. Mol. Neurodegen. 8, 20 (2013).
    • 47 Andersson M, Zetterberg H, Minthon L, Blennow K, Londos E. The cognitive profile and CSF biomarkers in dementia with Lewy bodies and Parkinson's disease dementia. Int. J. Geriatr. Psychiatry 26(1), 100–105 (2011).
    • 48 Del Campo M, Mollenhauer B, Bertolotto A et al. Recommendations to standardize preanalytical confounding factors in Alzheimer's and Parkinson's disease cerebrospinal fluid biomarkers: an update. Biomarkers Med. 6(4), 419–430 (2012).
    • 49 Parnetti L, Chiasserini D, Eusebi P et al. Performance of abeta1–40, abeta1–42, total tau, and phosphorylated tau as predictors of dementia in a cohort of patients with mild cognitive impairment. J. Alzheimers Dis. 29(1), 229–238 (2012).
    • 50 Lui JK, Laws SM, Li QX et al. Plasma amyloid-beta as a biomarker in Alzheimer's disease: the AIBL study of aging. J. Alzheimers Dis. 20(4), 1233–1242 (2010).
    • 51 Bateman RJ, Xiong C, Benzinger TL et al. Clinical and biomarker changes in dominantly inherited Alzheimer's disease. N. Engl. J. Med. 367(9), 795–804 (2012).
    • 52 Jack CR Jr, Knopman DS, Weigand SD et al. An operational approach to National Institute on Aging-Alzheimer's Association criteria for preclinical Alzheimer disease. Ann. Neurol. 71(6), 765–775 (2012).
    • 53 Jack CR Jr, Holtzman DM. Biomarker modeling of Alzheimer's disease. Neuron 80(6), 1347–1358 (2013).
    • 54 Shaffer JL, Petrella JR, Sheldon FC et al. Predicting cognitive decline in subjects at risk for Alzheimer disease by using combined cerebrospinal fluid, MR imaging, and PET biomarkers. Radiology 266(2), 583–591 (2013).
    • 55 Ikonomovic MD, Klunk WE, Abrahamson EE et al. Post-mortem correlates of in vivo PiB-PET amyloid imaging in a typical case of Alzheimer's disease. Brain 131(Pt 6), 1630–1645 (2008).
    • 56 Mathis CA, Lopresti BJ, Klunk WE. Impact of amyloid imaging on drug development in Alzheimer's disease. Nuclear Med. Biol. 34(7), 809–822 (2007).
    • 57 Shin J, Lee SY, Kim SH, Kim YB, Cho SJ. Multitracer PET imaging of amyloid plaques and neurofibrillary tangles in Alzheimer's disease. NeuroImage 43(2), 236–244 (2008).
    • 58 Bacskai BJ, Frosch MP, Freeman SH et al. Molecular imaging with Pittsburgh Compound B confirmed at autopsy: a case report. Arch. Neurol. 64(3), 431–434 (2007).
    • 59 Morris JC, Roe CM, Grant EA et al. Pittsburgh compound B imaging and prediction of progression from cognitive normality to symptomatic Alzheimer disease. Arch. Neurol. 66(12), 1469–1475 (2009).
    • 60 Resnick SM, Sojkova J, Zhou Y et al. Longitudinal cognitive decline is associated with fibrillar amyloid-beta measured by [11C]PiB. Neurology 74(10), 807–815 (2010).
    • 61 Weigand SD, Vemuri P, Wiste HJ et al. Transforming cerebrospinal fluid Abeta42 measures into calculated Pittsburgh Compound B units of brain Abeta amyloid. Alzheimers Dement. 7(2), 133–141 (2011).
    • 62 Villemagne VL, Ataka S, Mizuno T et al. High striatal amyloid beta-peptide deposition across different autosomal Alzheimer disease mutation types. Arch. Neurol. 66(12), 1537–1544 (2009).
    • 63 Raniga P, Bourgeat P, Fripp J et al. Automated (11)C-PiB standardized uptake value ratio. Acad. Radiol. 15(11), 1376–1389 (2008).
    • 64 Rowe CC, Ellis KA, Rimajova M et al. Amyloid imaging results from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging. Neurobiol. Aging 31(8), 1275–1283 (2010).
    • 65 Okello A, Koivunen J, Edison P et al. Conversion of amyloid positive and negative MCI to AD over 3 years: an 11C-PIB PET study. Neurology 73(10), 754–760 (2009).
    • 66 Bateman RJ, Xiong C, Benzinger TL et al. Clinical and biomarker changes in dominantly inherited Alzheimer's disease. N. Engl. J. Med. 367(9), 795–804 (2012).
    • 67 Rembach A, Watt AD, Wilson WJ et al. Plasma amyloid-beta levels are significantly associated with a transition toward Alzheimer's disease as measured by cognitive decline and change in neocortical amyloid burden. J. Alzheimers Dis. 40(1), 95–104 (2013).
    • 68 Wang T, Xiao S, Liu Y et al. The efficacy of plasma biomarkers in early diagnosis of Alzheimer's disease. Int. J. Geriatr. Psychiatr. (2013).
    • 69 Blennow K, De Meyer G, Hansson O et al. Evolution of Abeta42 and Abeta40 levels and Abeta42/Abeta40 ratio in plasma during progression of Alzheimer's disease: a multicenter assessment. J. Nutr. Health Aging 13(3), 205–208 (2009).
    • 70 Ruiz A, Pesini P, Espinosa A et al. Blood amyloid beta levels in healthy, mild cognitive impairment and Alzheimer's disease individuals: replication of diastolic blood pressure correlations and analysis of critical covariates. PLoS ONE 8(11), e81334 (2013).
    • 71 Fandrich M, Schmidt M, Grigorieff N. Recent progress in understanding Alzheimer's beta-amyloid structures. Trends Biochem. Sci. 36(6), 338–345 (2011).
    • 72 Metti AL, Cauley JA. How predictive of dementia are peripheral inflammatory markers in the elderly? Neurodegener. Dis. Manag. 2(6), 609–622 (2012).
    • 73 Arab L, Sadeghi R, Walker DG, Lue LF, Sabbagh MN. Consequences of aberrant insulin regulation in the brain: can treating diabetes be effective for Alzheimer's disease. Curr. Neuropharmacol. 9(4), 693–705 (2011).
    • 74 Blennow K, Hampel H, Weiner M, Zetterberg H. Cerebrospinal fluid and plasma biomarkers in Alzheimer disease. Nat. Rev. Neurol. 6(3), 131–144 (2010).
    • 75 Pahnke J, Walker LC, Scheffler K, Krohn M. Alzheimer's disease and blood-brain barrier function – why have anti-beta-amyloid therapies failed to prevent dementia progression? Neurosci. Biobehav. Rev. 33(7), 1099–1108 (2009).
    • 76 Nygaard HB. Current and emerging therapies for Alzheimer's disease. Clin. Therapeut. 35(10), 1480–1489 (2013).
    • 77 Gotz J, Eckert A, Matamales M, Ittner LM, Liu X. Modes of Abeta toxicity in Alzheimer's disease. Cell. Mol. Life Sci. 68(20), 3359–3375 (2011).
    • 78 Timmer NM, Kuiperij HB, De Waal RM, Verbeek MM. Do amyloid beta-associated factors co-deposit with Abeta in mouse models for Alzheimer's disease? J. Alzheimers Dis. 22(2), 345–355 (2010).
    • 79 Frost S, Kanagasingam Y, Sohrabi H et al. Retinal vascular biomarkers for early detection and monitoring of Alzheimer's disease. Translat. Psychiatr. 3, e233 (2013).
    • 80 Rowe C, Ellis K, Brown B et al. Cognition, hippocampal volume and fibrillar Aβ burden as predictors of cognitive decline: three-year follow-up results from AIBL. Alzheimer Dement. 8(4), P433 (2012).
    • 81 Kim J, Onstead L, Randle S et al. Abeta40 inhibits amyloid deposition in vivo. J. Neurosci. 27(3), 627–633 (2007).
    • 82 Howlett DR. APP transgenic mice and their application to drug discovery. Histol. Histopathol. 26(12), 1611–1632 (2011).
    • 83 Pharmaceutical Research and Manufacturer's of America. Alzheimer's research: setbacks and stepping stones (2012).
    • 84 ClinicalTrials.gov. US NIH. Studies found for Alzheimer's Organization. www.clinicaltrials.gov.
    • 85 Imbimbo BP, Giardina GA. gamma-secretase inhibitors and modulators for the treatment of Alzheimer's disease: disappointments and hopes. Curr. Topics Med. Chem. 11(12), 1555–1570 (2011).
    • 86 Salloway S, Sperling R, Fox NC et al. Two phase 3 trials of bapineuzumab in mild-to-moderate Alzheimer's disease. N. Engl. J. Med. 370(4), 322–333 (2014).
    • 87 Aisen PS, Gauthier S, Ferris SH et al. Tramiprosate in mild-to-moderate Alzheimer's disease – a randomized, double-blind, placebo-controlled, multi-centre study (the Alphase study). Arch. Med. Sci. 7(1), 102–111 (2011).
    • 88 Loeffler DA. Intravenous immunoglobulin and Alzheimer's disease: what now? J. Neuroinflam. 10(1), 70 (2013).
    • 89 Doody RS, Raman R, Farlow M et al. A Phase 3 trial of semagacestat for treatment of Alzheimer's disease. N. Engl. J. Med. 369(4), 341–350 (2013).
    • 90 Van Es JH, Van Gijn ME, Riccio O et al. Notch/gamma-secretase inhibition turns proliferative cells in intestinal crypts and adenomas into goblet cells. Nature 435(7044), 959–963 (2005).
    • 91 Wong GT, Manfra D, Poulet FM et al. Chronic treatment with the gamma-secretase inhibitor LY-411,575 inhibits beta-amyloid peptide production and alters lymphopoiesis and intestinal cell differentiation. J. Biol. Chem. 279(13), 12876–12882 (2004).
    • 92 Gravitz L. Drugs: a tangled web of targets. Nature 475(7355), S9–11 (2011).
    • 93 Salloway S, Sperling R, Brashear HR. Phase 3 trials of solanezumab and bapineuzumab for Alzheimer's disease. N. Engl. J. Med. 370(15), 1460 (2014).
    • 94 Prins ND, Scheltens P. Treating Alzheimer's disease with monoclonal antibodies: current status and outlook for the future. Alzheimers Res. Ther. 5(6), 56 (2013).
    • 95 Panza F, Solfrizzi V, Imbimbo BP, Tortelli R, Santamato A, Logroscino G. Amyloid-based immunotherapy for Alzheimer's disease in the time of prevention trials: the way forward. Expert Rev. Clin. Immunol. 10(3), 405–419 (2014).
    • 96 Carrera I, Etcheverria I, Fernandez-Novoa L, Lombardi V, Cacabelos R, Vigo C. Vaccine development to treat Alzheimer's disease neuropathology in APP/PS1 transgenic mice. Int. J. Alzheimer's Dis. 2012, 376138 (2012).
    • 97 Winblad B, Graf A, Riviere ME, Andreasen N, Ryan JM. Active immunotherapy options for Alzheimer's disease. Alzheimers Res. Ther. 6(1), 7 (2014).
    • 98 Tan CC, Yu JT, Tan MS, Jiang T, Zhu XC, Tan L. Autophagy in aging and neurodegenerative diseases: implications for pathogenesis and therapy. Neurobiol. Aging 35(5), 941–957 (2014).
    • 99 Wolfe DM, Lee JH, Kumar A, Lee S, Orenstein SJ, Nixon RA. Autophagy failure in Alzheimer's disease and the role of defective lysosomal acidification. Eur. J. Neurosci. 37(12), 1949–1961 (2013).
    • 100 Pickford F, Masliah E, Britschgi M et al. The autophagy-related protein beclin 1 shows reduced expression in early Alzheimer disease and regulates amyloid beta accumulation in mice. J. Clin. Investig. 118(6), 2190–2199 (2008).
    • 101 Bharadwaj PR, Verdile G, Barr RK et al. Latrepirdine (dimebon) enhances autophagy and reduces intracellular GFP-Abeta42 levels in yeast. J. Alzheimers Dis. 32(4), 949–967 (2012).
    • 102 Steele JW, Lachenmayer ML, Ju S et al. Latrepirdine improves cognition and arrests progression of neuropathology in an Alzheimer's mouse model. Mol. Psychiatr. 18(8), 889–897 (2013).
    • 103 Bharadwaj PR, Bates KA, Porter T et al. Latrepirdine: molecular mechanisms underlying potential therapeutic roles in Alzheimer's and other neurodegenerative diseases. Translat. Psychiatr. 3, e332 (2013).
    • 104 Marchesi VT. Alzheimer's disease 2012: the great amyloid gamble. Am. J. Pathol. 180(5), 1762–1767 (2012).
    • 105 Kerbage C, Sadowsky CH, Jennings D, Cagle GD, Hartung PD. Alzheimer's disease diagnosis by detecting exogenous fluorescent signal of ligand bound to Beta amyloid in the lens of human eye: an exploratory study. Front. Neurol. 4, 62 (2013).
    • 106 Kirbas S, Turkyilmaz K, Anlar O, Tufekci A, Durmus M. Retinal nerve fiber layer thickness in patients with Alzheimer disease. J. Neuroophthalmol. 33(1), 58–61 (2013).
    • 107 Mandal PK, Joshi J, Saharan S. Visuospatial perception: an emerging biomarker for Alzheimer's disease. J. Alzheimers Dis. 31(Suppl. 3), S117–S135 (2012).