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Nelson PT, Dimayuga J, Wilfred BR. MicroRNA in Situ Hybridization in the Human Entorhinal and Transentorhinal Cortex. Front Hum Neurosci 2010; 4:7. [PMID: 20204141 PMCID: PMC2831629 DOI: 10.3389/neuro.09.007.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 01/21/2010] [Indexed: 11/15/2022] Open
Abstract
MicroRNAs (miRNAs) play key roles in gene expression regulation in both healthy and disease brains. To better understand those roles, it is necessary to characterize the miRNAs that are expressed in particular cell types under a range of conditions. In situ hybridization (ISH) can demonstrate cell- and lamina-specific patterns of miRNA expression that would be lost in tissue-level expression profiling. In the present study, ISH was performed with special focus on the human entorhinal cortex (EC) and transentorhinal cortex (TEC). The TEC is the area of the cerebral cortex that first develops neurofibrillary tangles in Alzheimer's disease (AD). However, the reason for TEC's special vulnerability to AD-type pathology is unknown. MiRNA ISH was performed on three human brains with well-characterized clinical and pathological parameters. Locked nucleic acid ISH probes were used referent to miR-107, miR-124, miR-125b, and miR-320. In order to correlate the ISH data with AD pathology, the ISH staining was compared with near-adjacent slides processed using Thioflavine stains. Not all neurons or cortical lamina stain with equal intensity for individual miRNAs. As with other areas of brain, the TEC and EC have characteristic miRNA expression patterns. MiRNA ISH is among the first methods to show special staining characteristics of cells and laminae of the human TEC.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology and Division of Neuropathology, University of Kentucky Medical Center, Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky Lexington, KY, USA
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Nelson PT, Kryscio RJ, Jicha GA, Abner EL, Schmitt FA, Xu LO, Cooper G, Smith CD, Markesbery WR. Relative preservation of MMSE scores in autopsy-proven dementia with Lewy bodies. Neurology 2009; 73:1127-33. [PMID: 19805729 DOI: 10.1212/wnl.0b013e3181bacf9e] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Recent studies raised questions about the severity of cognitive impairment associated with dementia with Lewy bodies (DLB). However, there have been few analyses of large, multicenter data registries for clinical-pathologic correlation. METHODS We evaluated data from the National Alzheimer's Coordinating Center registry (n = 5,813 cases meeting initial inclusion criteria) and the University of Kentucky Alzheimer's Disease Center autopsy series (n = 527) to compare quantitatively the severity of cognitive impairment associated with DLB pathology vs Alzheimer disease (AD) and AD+DLB pathologies. RESULTS Mini-Mental State Examination (MMSE) scores showed that persons with pure DLB had cognitive impairment of relatively moderate severity (final MMSE score 15.6 +/- 8.7) compared to patients with pure AD and AD+DLB (final MMSE score 10.7 +/- 8.6 and 10.6 +/- 8.6). Persons with pure DLB pathology from both data sets had more years of formal education and were more likely to be male. Differences in final MMSE scores were significant (p < 0.01) between pure DLB and both AD+DLB and pure AD even after correction for education level, gender, and MMSE-death interval. Even in cases with extensive neocortical LBs, the degree of cognitive impairment was most strongly related to the amount of concomitant AD-type neurofibrillary pathology. CONCLUSIONS Dementia with Lewy bodies can constitute a debilitating disease with associated psychiatric, motoric, and autonomic dysfunction. However, neocortical Lewy bodies are not a substrate for severe global cognitive impairment as assessed by the Mini-Mental State Examination. Instead, neocortical Lewy bodies appear to constitute or reflect an additive disease process, requiring Alzheimer disease or other concomitant brain diseases to induce severe global cognitive deterioration.
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Affiliation(s)
- P T Nelson
- Department of Pathology, Division of Neuropathology, University of Kentucky Medical Center, 800 S. Limestone, University of Kentucky, Lexington, KY 40536-0230, USA.
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Cognitive decline in Alzheimer's disease is associated with selective changes in calcineurin/NFAT signaling. J Neurosci 2009; 29:12957-69. [PMID: 19828810 DOI: 10.1523/jneurosci.1064-09.2009] [Citation(s) in RCA: 217] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Upon activation by calcineurin, the nuclear factor of activated T-cells (NFAT) translocates to the nucleus and guides the transcription of numerous molecules involved in inflammation and Ca(2+) dysregulation, both of which are prominent features of Alzheimer's disease (AD). However, NFAT signaling in AD remains relatively uninvestigated. Using isolated cytosolic and nuclear fractions prepared from rapid-autopsy postmortem human brain tissue, we show that NFATs 1 and 3 shifted to nuclear compartments in the hippocampus at different stages of neuropathology and cognitive decline, whereas NFAT2 remained unchanged. NFAT1 exhibited greater association with isolated nuclear fractions in subjects with mild cognitive impairment (MCI), whereas NFAT3 showed a strong nuclear bias in subjects with severe dementia and AD. Similar to NFAT1, calcineurin-Aalpha also exhibited a nuclear bias in the early stages of cognitive decline. But, unlike NFAT1 and similar to NFAT3, the nuclear bias for calcineurin became more pronounced as cognition worsened. Changes in calcineurin/NFAT3 were directly correlated to soluble amyloid-beta (Abeta((1-42))) levels in postmortem hippocampus, and oligomeric Abeta, in particular, robustly stimulated NFAT activation in primary rat astrocyte cultures. Oligomeric Abeta also caused a significant reduction in excitatory amino acid transporter 2 (EAAT2) protein levels in astrocyte cultures, which was blocked by NFAT inhibition. Moreover, inhibition of astrocytic NFAT activity in mixed cultures ameliorated Abeta-dependent elevations in glutamate and neuronal death. The results suggest that NFAT signaling is selectively altered in AD and may play an important role in driving Abeta-mediated neurodegeneration.
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Katsel P, Tan W, Haroutunian V. Gain in brain immunity in the oldest-old differentiates cognitively normal from demented individuals. PLoS One 2009; 4:e7642. [PMID: 19865478 PMCID: PMC2764344 DOI: 10.1371/journal.pone.0007642] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 10/04/2009] [Indexed: 11/18/2022] Open
Abstract
Background Recent findings suggest that Alzheimer's disease (AD) neuropathological features (neuritic plaques and NFTs) are not strongly associated with dementia in extreme old (over 90 years of age) and compel a search for neurobiological indices of dementia in this rapidly growing segment of the elderly population. We sought to characterize transcriptional and protein profiles of dementia in the oldest-old. Methods and Findings Gene and protein expression changes relative to non-demented age-matched controls were assessed by two microarray platforms, qPCR and Western blot in different regions of the brains of oldest-old and younger old persons who died at mild or severe stages of dementia. Our results indicate that: i) consistent with recent neuropathological findings, gene expression changes associated with cognitive impairment in oldest-old persons are distinct from those in cognitively impaired youngest-old persons; ii) transcripts affected in young-old subjects with dementia participate in biological pathways related to synaptic function and neurotransmission while transcripts affected in oldest-old subjects with dementia are associated with immune/inflammatory function; iii) upregulation of immune response genes in cognitively intact oldest-old subjects and their subsequent downregulation in dementia suggests a potential protective role of the brain immune-associated system against dementia in the oldest-old; iv) consistent with gene expression profiles, protein expression of several selected genes associated with the inflammatory/immune system in inferior temporal cortex is significantly increased in cognitively intact oldest-old persons relative to cognitively intact young-old persons, but impaired in cognitively compromised oldest-old persons relative to cognitively intact oldest-old controls. Conclusions These results suggest that disruption of the robust immune homeostasis that is characteristic of oldest-old individuals who avoided dementia may be directly associated with dementia in the oldest-old and contrast with the synaptic and neurotransmitter system failures that typify dementia in younger old persons.
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Affiliation(s)
- Pavel Katsel
- Department of Psychiatry, Mount Sinai School of Medicine, New York, New York, USA.
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Nelson PT, Jicha GA, Kryscio RJ, Abner EL, Schmitt FA, Cooper G, Xu LO, Smith CD, Markesbery WR. Low sensitivity in clinical diagnoses of dementia with Lewy bodies. J Neurol 2009; 257:359-66. [PMID: 19795154 DOI: 10.1007/s00415-009-5324-y] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 08/24/2009] [Accepted: 09/11/2009] [Indexed: 11/30/2022]
Abstract
The success of future neurodegenerative disease (ND) therapies depends partly on accurate antemortem diagnoses. Relatively few prior studies have been performed on large, multicenter-derived datasets to test the accuracy of final clinical ND diagnoses in relation to definitive neuropathological findings. Data were analyzed from the University of Kentucky Alzheimer's Disease Center autopsy series and from the National Alzheimer's Coordinating Center (NACC) registry. NACC data are derived from 31 different academic medical centers, each with strong clinical expertise and infrastructure pertaining to NDs. The final clinical diagnoses were compared systematically with subsequent neuropathology diagnoses. Among subjects meeting final inclusion criteria (N = 2,861 for NACC Registry data), the strength of the associations between clinical diagnoses and subsequent ND diagnoses was only moderate. This was particularly true in the case of dementia with Lewy bodies (DLB): the sensitivity of clinical diagnoses was quite low (32.1% for pure DLB and 12.1% for Alzheimer's disease (AD + DLB) although specificity was over 95%. AD clinical diagnoses were more accurate (85.0% sensitivity and 51.1% specificity). The accuracy of clinical DLB diagnoses became somewhat lower over the past decade, due apparently to increased "over-calling" the diagnosis in patients with severe cognitive impairment. Furthermore, using visual hallucinations, extrapyramidal signs, and/or fluctuating cognition as part of the clinical criteria for DLB diagnosis was of minimal utility in a group (N = 237) with high prevalence of severe dementia. Our data suggest that further work is needed to refine our ability to identify specific aging-related brain disease mechanisms, especially in DLB.
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Affiliation(s)
- Peter T Nelson
- Division of Neuropathology, Department of Pathology, University of Kentucky Medical Center, University of Kentucky, Rm 311, Sanders-Brown Building, 800 S. Limestone, Lexington, KY 40536-0230, USA.
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207
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Schneider JA, Arvanitakis Z, Leurgans SE, Bennett DA. The neuropathology of probable Alzheimer disease and mild cognitive impairment. Ann Neurol 2009; 66:200-8. [PMID: 19743450 DOI: 10.1002/ana.21706] [Citation(s) in RCA: 629] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Mixed pathologies are common in older persons with dementia. Little is known about mixed pathologies in probable Alzheimer disease (AD) and about the spectrum of neuropathology in mild cognitive impairment (MCI). The objective of this study was to investigate single and mixed common age-related neuropathologies in persons with probable AD and MCI. METHODS The study included 483 autopsied participants from the Religious Orders Study and the Rush Memory and Aging Project with probable AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria), MCI (amnestic and nonamnestic), or no cognitive impairment. We excluded 41 persons with clinically possible AD and 14 with other dementias. We documented the neuropathology of AD (National Institute on Aging-Reagan criteria), macroscopic cerebral infarcts, and neocortical Lewy body (LB) disease. RESULTS Of 179 persons (average age, 86.9 years) with probable AD, 87.7% had pathologically confirmed AD, and 45.8% had mixed pathologies, most commonly AD with macroscopic infarcts (n = 54), followed by AD with neocortical LB disease (n = 19) and both (n = 8). Of the 134 persons with MCI, 54.4% had pathologically diagnosed AD (58.7% amnestic; 49.2% nonamnestic); 19.4% had mixed pathologies (22.7% amnestic; 15.3% nonamnestic). Macroscopic infarcts without pathologically diagnosed AD accounted for 4.5% of probable AD, 13.3% of amnestic MCI, and 18.6% of nonamnestic MCI. Pure neocortical LB disease was uncommon in all persons with cognitive impairment (<6%). Microscopic infarcts (without macroscopic infarcts) were common as a mixed pathology, but rarely accounted for a clinical diagnosis of probable AD (n = 4) or MCI (n = 3). INTERPRETATION Clinically diagnosed probable AD and MCI, even amnestic MCI, are pathologically heterogeneous disorders, with many persons exhibiting mixed pathologies.
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Affiliation(s)
- Julie A Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA.
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208
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The unsolved relationship of brain aging and late-onset Alzheimer disease. Biochim Biophys Acta Gen Subj 2009; 1790:1124-32. [DOI: 10.1016/j.bbagen.2009.07.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 07/08/2009] [Accepted: 07/10/2009] [Indexed: 11/23/2022]
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Sarsoza F, Saing T, Kayed R, Dahlin R, Dick M, Broadwater-Hollifield C, Mobley S, Lott I, Doran E, Gillen D, Anderson-Bergman C, Cribbs DH, Glabe C, Head E. A fibril-specific, conformation-dependent antibody recognizes a subset of Abeta plaques in Alzheimer disease, Down syndrome and Tg2576 transgenic mouse brain. Acta Neuropathol 2009; 118:505-17. [PMID: 19360426 PMCID: PMC2737113 DOI: 10.1007/s00401-009-0530-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Revised: 03/11/2009] [Accepted: 03/29/2009] [Indexed: 12/20/2022]
Abstract
Beta-amyloid (Abeta) is thought to be a key contributor to the pathogenesis of Alzheimer disease (AD) in the general population and in adults with Down syndrome (DS). Different assembly states of Abeta have been identified that may be neurotoxic. Abeta oligomers can assemble into soluble prefibrillar oligomers, soluble fibrillar oligomers and insoluble fibrils. Using a novel antibody, OC, recognizing fibrils and soluble fibrillar oligomers, we characterized fibrillar Abeta deposits in AD and DS cases. We further compared human specimens to those obtained from the Tg2576 mouse model of AD. Our results show that accumulation of fibrillar immunoreactivity is significantly increased in AD relative to nondemented aged subjects and those with select cognitive impairments (p < 0.0001). Further, there was a significant correlation between the extent of frontal cortex fibrillar deposit accumulation and dementia severity (MMSE r = -0.72). In DS, we observe an early age of onset and age-dependent accumulation of fibrillar OC immunoreactivity with little pathology in similarly aged non-DS individuals. Tg2576 mice show fibrillar accumulation that can be detected as young as 6 months. Interestingly, fibril-specific immunoreactivity was observed in diffuse, thioflavine S-negative Abeta deposits in addition to more mature neuritic plaques. These results suggest that fibrillar deposits are associated with disease in both AD and in adults with DS and their distribution within early Abeta pathology associated with diffuse plaques and correlation with MMSE suggest that these deposits may not be as benign as previously thought.
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Affiliation(s)
- Floyd Sarsoza
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
| | - Tommy Saing
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
| | - Rakez Kayed
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697 USA
| | - Robert Dahlin
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
| | - Malcolm Dick
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
| | | | - Scott Mobley
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
| | - Ira Lott
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Neurology, University of California, Irvine, CA 92697 USA
- Department of Pediatrics, University of California, Irvine, CA 92697 USA
| | - Eric Doran
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Pediatrics, University of California, Irvine, CA 92697 USA
| | - Daniel Gillen
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Statistics, University of California, Irvine, CA 92697 USA
| | - Clifford Anderson-Bergman
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Statistics, University of California, Irvine, CA 92697 USA
| | - David H. Cribbs
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Neurology, University of California, Irvine, CA 92697 USA
| | - Charles Glabe
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697 USA
| | - Elizabeth Head
- Institute for Brain Aging and Dementia, University of California, Irvine, CA 92697 USA
- Department of Neurology, University of California, Irvine, CA 92697 USA
- Department of Molecular and Biomedical Pharmacology, Sanders-Brown Center on Aging, University of Kentucky, 203 Sanders-Brown Building, 800 South Limestone Street, Lexington, KY 40536 USA
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Alzheimer's disease biomarker discovery in symptomatic and asymptomatic patients: experimental approaches and future clinical applications. Exp Gerontol 2009; 45:15-22. [PMID: 19796674 DOI: 10.1016/j.exger.2009.09.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 09/21/2009] [Accepted: 09/24/2009] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly. Current treatments for AD are not as effective as needed, nor is there any definitive antemortem diagnostic. Understanding the biological processes that occur during AD onset and/or progression will improve disease diagnosis and treatment. Recent applications of microarray technologies for analysis of messenger (m) RNA expression profiles have elucidated distinct changes in the brain as a function of AD dementia initiation and progression. However, mRNA analysis underestimates post-transcriptional modifications and therefore provides only a partial view of the molecular changes in the AD brain. Combining mRNA studies with protein expression analysis may provide a more global picture of the biological processes associated with AD dementia. Information gathered could lead to the development of select biological indices (biomarkers) for guiding AD diagnosis and therapy. We will provide a brief background on AD, followed by a review on the applications of microarray, proteomics, as well as microRNA expression profile analysis to develop novel diagnostic strategies that may be useful for the diagnosis AD and for monitoring disease progression. The availability of biomarkers that promote early disease diagnosis, particularly among asymptomatic patients, will lead to the application of personalized medicine in AD.
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211
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Bartzokis G. Alzheimer's disease as homeostatic responses to age-related myelin breakdown. Neurobiol Aging 2009; 32:1341-71. [PMID: 19775776 DOI: 10.1016/j.neurobiolaging.2009.08.007] [Citation(s) in RCA: 382] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 08/13/2009] [Accepted: 08/17/2009] [Indexed: 12/11/2022]
Abstract
The amyloid hypothesis (AH) of Alzheimer's disease (AD) posits that the fundamental cause of AD is the accumulation of the peptide amyloid beta (Aβ) in the brain. This hypothesis has been supported by observations that genetic defects in amyloid precursor protein (APP) and presenilin increase Aβ production and cause familial AD (FAD). The AH is widely accepted but does not account for important phenomena including recent failures of clinical trials to impact dementia in humans even after successfully reducing Aβ deposits. Herein, the AH is viewed from the broader overarching perspective of the myelin model of the human brain that focuses on functioning brain circuits and encompasses white matter and myelin in addition to neurons and synapses. The model proposes that the recently evolved and extensive myelination of the human brain underlies both our unique abilities and susceptibility to highly prevalent age-related neuropsychiatric disorders such as late onset AD (LOAD). It regards oligodendrocytes and the myelin they produce as being both critical for circuit function and uniquely vulnerable to damage. This perspective reframes key observations such as axonal transport disruptions, formation of axonal swellings/sphenoids and neuritic plaques, and proteinaceous deposits such as Aβ and tau as by-products of homeostatic myelin repair processes. It delineates empirically testable mechanisms of action for genes underlying FAD and LOAD and provides "upstream" treatment targets. Such interventions could potentially treat multiple degenerative brain disorders by mitigating the effects of aging and associated changes in iron, cholesterol, and free radicals on oligodendrocytes and their myelin.
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Affiliation(s)
- George Bartzokis
- Department of Psychiatry and Biobehavioral Sciences, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Haroutunian V, Hoffman LB, Beeri MS. Is there a neuropathology difference between mild cognitive impairment and dementia? DIALOGUES IN CLINICAL NEUROSCIENCE 2009. [PMID: 19585952 PMCID: PMC3073531 DOI: 10.31887/dcns.2009.11.2/vharoutunian] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The number of studies that have investigated the neuropathology of mild cognitive impairment (MCI) is small, but growing. In this paper we have restricted our focus to the consideration of the presence and extent of postmortem findings relevant to the neuropathology of Alzheimer's disease. We have drawn from studies that have investigated the postmortem neurobiology of the brains of persons with cognitive function at the interface between unimpaired normal function and mild but definite dementia. The data derived from these studies suggest that i) the brains of persons with MCI evidence significant neuropathological and neurobiological changes relative to those without cognitive impairment; ii) in general, the neuropathological and neurobiological changes are qualitatively similar to those observed in the brains of persons with frank AD-like dementia; and iii) the neuropathological and neurobiological brain changes associated with MCI are quantitatively less than those of persons who meet criteria for dementia. Thus, the available, albeit limited, data suggests that MCI is associated with the early stages of the neurobiological and neuropathological changes that culminate in the florid lesions of AD; including the accumulation of neuritic plaques, neurofibrillary tangles, synaptic and neurotransmitter associated deficits, and significant neuronal cell death.
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Affiliation(s)
- Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY, USA.
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213
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Nelson PT, Abner EL, Schmitt FA, Kryscio RJ, Jicha GA, Santacruz K, Smith CD, Patel E, Markesbery WR. Brains with medial temporal lobe neurofibrillary tangles but no neuritic amyloid plaques are a diagnostic dilemma but may have pathogenetic aspects distinct from Alzheimer disease. J Neuropathol Exp Neurol 2009; 68:774-84. [PMID: 19535994 DOI: 10.1097/nen.0b013e3181aacbe9] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Brains that have many neurofibrillary tangles (NFTs) in medial temporal lobe structures (Braak stage III or IV) but no cortical neuritic plaques (NPs) may be a diagnostic dilemma; they also raise questions about the amyloid cascade hypothesis of Alzheimer disease (AD) in which NFT development is thought to occur downstream of the development of amyloid plaques. To determine the clinical, demographic, and biological factors related to NFT+/NP- cases, we analyzed 26 NFT+/NP- patient brains identified from the University of Kentucky AD Center autopsy cohort (n=502); most of these patients were at least 85 years old and lacked profound antemortem cognitive impairment. A subset of the cases had NFTs in the medulla oblongata. Aberrant trans-activator regulatory DNA-binding protein 43 immunohistochemical staining was seen in 5 of the 26 cases with the clinical diagnoses of AD or mild cognitive impairment. We also queried cases in the National Alzheimer's Coordinating Center Registry (n=5,108) and found 219 NFT+/NP- cases. Those patients had a relatively high likelihood of belonging to a birth cohort with the highest incidence of influenza infection during the 1918 to 1919 pandemic. This observation may link the pathogenesis in NFT+/NP- cases to encephalitis during childhood. We conclude that NFT+/NP- cases comprise approximately 5% of aged individuals in multiple data sets; these cases are not necessarily within the spectrum of AD.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology and Division of Neuropathology, Univerisity of Kentucky, Lexington, Kentucky 40536-0230, USA.
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Nelson PT, Smith CD, Abner EA, Schmitt FA, Scheff SW, Davis GJ, Keller JN, Jicha GA, Davis D, Wang-Xia W, Hartman A, Katz DG, Markesbery WR. Human cerebral neuropathology of Type 2 diabetes mellitus. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:454-69. [PMID: 18789386 PMCID: PMC2834412 DOI: 10.1016/j.bbadis.2008.08.005] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 08/09/2008] [Accepted: 08/14/2008] [Indexed: 12/15/2022]
Abstract
The cerebral neuropathology of Type 2 diabetes (CNDM2) has not been positively defined. This review includes a description of CNDM2 research from before the 'Pubmed Era'. Recent neuroimaging studies have focused on cerebrovascular and white matter pathology. These and prior studies about cerebrovascular histopathology in diabetes are reviewed. Evidence is also described for and against the link between CNDM2 and Alzheimer's disease pathogenesis. To study this matter directly, we evaluated data from University of Kentucky Alzheimer's Disease Center (UK ADC) patients recruited while non-demented and followed longitudinally. Of patients who had come to autopsy (N = 234), 139 met inclusion criteria. These patients provided the basis for comparing the prevalence of pathological and clinical indices between well-characterized cases with (N = 50) or without (N = 89) the premortem diagnosis of diabetes. In diabetics, cerebrovascular pathology was more frequent and Alzheimer-type pathology was less frequent than in non-diabetics. Finally, a series of photomicrographs demonstrates histopathological features (including clinical-radiographical correlation) observed in brains of persons that died after a history of diabetes. These preliminary, correlative, and descriptive studies may help develop new hypotheses about CNDM2. We conclude that more work should be performed on human material in the context of CNDM2.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology, Division of Neuropathology, University of Kentucky Medical Center, Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky, Lexington, KY 40536-0230, USA.
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215
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Neuropathology and cognitive impairment in Alzheimer disease: a complex but coherent relationship. J Neuropathol Exp Neurol 2009; 68:1-14. [PMID: 19104448 DOI: 10.1097/nen.0b013e3181919a48] [Citation(s) in RCA: 429] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Amyloid plaques and neurofibrillary tangles (NFTs) are the pathological hallmarks of Alzheimer disease (AD). There is controversy regarding the use of current diagnostic criteria for AD and whether amyloid plaques and NFTs contribute to cognitive impairment. Because AD is specific to humans, rigorous and comprehensiveclinicopathologic studies are necessary to test and refine hypotheses of AD diagnosis and pathogenesis. Neither the clinical nor the pathological aspects of AD evolve in a linear manner, but thepredictable sequence of AD pathology allows for stage-based correlations with cognitive deterioration. We discuss subsets of patients with clinical dementia who lack amyloid plaques and NFTs and, conversely, whether individuals without antemortem cognitive impairment can harbor severe AD-type pathological findings at autopsy. There are many medical, technical, and anatomical challenges to clinicopathologic studies in AD. For example, at least two thirds of persons older than 80 years have non-AD brain diseases that can effect on cognitive function. We argue that existing data strongly support the hypothesis that both amyloid plaques and NFTs contribute to cognitive impairment.
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216
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Nelson PT, Kryscio RJ, Abner EL, Schmitt FA, Jicha GA, Mendiondo MS, Cooper G, Smith CB, Markesbery WR. Acetylcholinesterase inhibitor treatment is associated with relatively slow cognitive decline in patients with Alzheimer's disease and AD + DLB. J Alzheimers Dis 2009; 16:29-34. [PMID: 19158418 DOI: 10.3233/jad-2009-0926] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Dementia can be caused by different diseases including Alzheimer's disease (AD), dementia with Lewy bodies (DLB), or both (AD + DLB). University of Kentucky AD Center pathologically-diagnosed AD and AD + DLB cases were evaluated who had three or more longitudinal antemortem mental status examinations (n = 156). Patients with important concomitant pathology (n = 5) or patients that were profoundly demented at recruitment (intake MMSE < 20; n = 86) were excluded to strengthen our ability to test the association of specific clinical and pathological indices. Patients with pathologically-diagnosed AD + DLB (n = 25) lost cognitive capacity faster than patients with AD alone (n = 40). In both diseases, treatment with acetylcholinesterase inhibitors was associated with a slower rate of cognitive decline.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology, University of Kentucky Medical Center, University of Kentucky, Lexington, KY, USA.
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217
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Criteria for the neuropathological diagnosis of dementing disorders: routes out of the swamp? Acta Neuropathol 2009; 117:101-10. [PMID: 19052757 DOI: 10.1007/s00401-008-0466-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 11/24/2008] [Accepted: 11/24/2008] [Indexed: 10/21/2022]
Abstract
There are several consensus criteria for both the clinical and neuropathological diagnosis of different types of dementias. The clinical diagnostic accuracy using revised research criteria and newly developed biomarkers (MRI, PET, CSF analysis, genetic markers) ranges from 65 to 96% (for Alzheimer disease) with a specificity of diagnostic criteria versus other dementias of 23-88%. Neuropathological assessment of dementing disorders using immunohistochemistry, molecular biologic and genetic methods can achieve a diagnosis/classification, based on the homogeneous definitions, harmonized inter-laboratory methods and standards for the assessment of nervous system lesions, in about 99%, without, however, being able to clarify the causes/etiology of most of these disorders. Further prospective and concerted clinicopathological studies using revised methodological and validated protocols and uniform techniques are required to establish the nature, distribution pattern and grades of lesions and; thus, to overcome the limitations of the current diagnostic framework. By data fusion this my allow their more uniform application and correlation with the clinical data in order to approach a diagnostic "gold standard", and to create generally accepted criteria for differentiating cognitive disorders from healthy brain aging. The detection of disease-specific pathologies will be indispensable to determinate the efficacy of new therapy options.
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218
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Jicha GA, Schmitt FA, Abner E, Nelson PT, Cooper GE, Smith CD, Markesbery WR. Prodromal clinical manifestations of neuropathologically confirmed Lewy body disease. Neurobiol Aging 2008; 31:1805-13. [PMID: 19026468 DOI: 10.1016/j.neurobiolaging.2008.09.017] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 08/30/2008] [Accepted: 09/30/2008] [Indexed: 11/26/2022]
Abstract
The mild cognitive impairment (MCI) stage of dementia with Lewy bodies (MCI-DLB) has not yet been defined, but is likely to differ in the MCI stage of Alzheimer's disease (MCI-AD). To determine whether clinical features distinguish MCI-DLB and MCI-AD, 9 cases of neuropathologically confirmed MCI-DLB and 12 cases of MCI-AD were compared. No significant differences were found between MCI-DLB and MCI-AD cases in age at death, gender, ApoE status, education, time followed while clinically normal, or duration of MCI. MCI-DLB and MCI-AD cases differed clinically in the expression of Parkinsonism (P=0.012), provoked hallucinations or delirium (P=0.042), or the presence of any of these noncognitive symptoms of DLB (P<0.0001). Letter fluency (P=0.007) was significantly lower and Wechsler Logical Memory I (P=0.019) was significantly higher in MCI-DLB compared to MCI-AD cases. These data demonstrate the feasibility of differentiating underlying pathologic processes responsible for cognitive decline in the preclinical disease state and suggest that further refinement in diagnostic criteria may allow more accurate early detection of prodromal DLB and AD.
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Affiliation(s)
- G A Jicha
- Department of Neurology, University of Kentucky College of Medicine, Lexington, KY 40536, USA.
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219
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Nelson PT, Abner EL, Schmitt FA, Kryscio RJ, Jicha GA, Smith CD, Davis DG, Poduska JW, Patel E, Mendiondo MS, Markesbery WR. Modeling the association between 43 different clinical and pathological variables and the severity of cognitive impairment in a large autopsy cohort of elderly persons. Brain Pathol 2008; 20:66-79. [PMID: 19021630 DOI: 10.1111/j.1750-3639.2008.00244.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We evaluated the association between mini-mental status examination (MMSE) scores proximal to death and the values of 43 different clinical and pathological parameters. Studies were performed using data from 334 elderly, longitudinally evaluated research subjects who had undergone autopsy and satisfied inclusion criteria from an initial study group of 501. Interindividual variance in MMSE scores was used as a surrogate for the severity of cognitive impairment linked to aging (CILA). A statistical linear regression-based model provided a framework for assessing the parameters with significant, direct impact on CILA severity. Strong association between CILA and Alzheimer's disease (AD) pathology, especially isocortical neurofibrillary tangles, was evident. The pattern of association between AD lesion densities with cognitive impairment severity was biologically informative, with neuritic plaques having more impact in relatively high-functioning individuals. Abundant isocortical Lewy bodies tended to be an additive pathology correlating with final MMSE scores approximately 10 points lower. In a subset of cases we found evidence for association between TDP-43-related pathology and CILA severity, independent of AD or hippocampal sclerosis. There was no support for independent association between CILA severity and most evaluated indices including diffuse plaques, argyrophilic grains, heart disease, education level, apolipoprotein E alleles or diabetes.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology and Division of Neuropathology, University of Kentucky Medical Center, Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky, Lexington, KY, USA.
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220
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Nelson PT, Abner EL, Scheff SW, Schmitt FA, Kryscio RJ, Jicha GA, Smith CD, Patel E, Markesbery WR. Alzheimer's-type neuropathology in the precuneus is not increased relative to other areas of neocortex across a range of cognitive impairment. Neurosci Lett 2008; 450:336-9. [PMID: 19010392 DOI: 10.1016/j.neulet.2008.11.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/03/2008] [Accepted: 11/04/2008] [Indexed: 11/18/2022]
Abstract
We studied Alzheimer's disease (AD) pathology in the precuneus and surrounding brain areas. Anatomically, the precuneus corresponds to the medial portion of human cerebral cortical Brodmann Area 7. This study utilized patients from the University of Kentucky Alzheimer's Disease Center autopsy cohort. Data from 47 brains were used comprising patients of differing antemortem cognitive impairment severities, each with longitudinal clinical data and extensive neuropathological data. We assessed whether the precuneus and surrounding areas are differentially vulnerable to AD-type pathological lesions (diffuse amyloid plaques, neuritic amyloid plaques, and neurofibrillary tangles). Eleven areas of brain were evaluated for each case: amygdala, hippocampal CA1, subiculum, entorhinal cortex, frontal cortex, superior and middle temporal gyri, inferior parietal lobule, occipital cortex, posterior cingulate gyrus, Brodmann Area 31, and the precuneus proper. Like other areas of neocortex, the precuneus demonstrated increased diffuse and neuritic amyloid plaques early in the evolution in AD, and increased neurofibrillary tangles late in AD. Correcting for the antemortem cognitive status of the patients, there was no evidence of an increase in the density of AD-type pathology in the precuneus or neighboring areas relative to other areas of cerebral neocortex. Our results are not consistent with the idea that the precuneus is involved in a special way with plaques or tangles relative to other areas of neocortex.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology and Division of Neuropathology, University of Kentucky Medical Center, Sanders-Brown Center on Aging and Alzheimer's Disease Center, University of Kentucky, Lexington, KY 40536, USA.
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221
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Haroutunian V, Schnaider-Beeri M, Schmeidler J, Wysocki M, Purohit DP, Perl DP, Libow LS, Lesser GT, Maroukian M, Grossman HT. Role of the neuropathology of Alzheimer disease in dementia in the oldest-old. ACTA ACUST UNITED AC 2008; 65:1211-7. [PMID: 18779425 DOI: 10.1001/archneur.65.9.1211] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Neuritic plaques (NPs) and neurofibrillary tangles (NFTs) in the brain, especially in the hippocampus, entorhinal cortex, and isocortex, are hallmark lesions of Alzheimer disease and dementia in the elderly. However, this association has not been extensively studied in the rapidly growing population of the very old. OBJECTIVE To assess the relationship between estimates of cognitive function and NP and NFT pathologic conditions in 317 autopsied persons aged 60 to 107 years. DESIGN We studied the relationship between severity of dementia and the density of these characteristic lesions of Alzheimer disease in young-old, middle-old, and oldest-old persons. The relationship of the severity of dementia as measured by the Clinical Dementia Rating scale to the density of NPs and NFTs was then assessed in each age group. PARTICIPANTS Three hundred seventeen brains of persons aged 60 years and older were selected to have either no remarkable neuropathological lesions or only NP and NFT lesions. Brains with any other neuropathological conditions, either alone or in addition to Alzheimer disease findings, were excluded. The study cohort was then stratified into the youngest quartile (aged 60-80 years), middle 2 quartiles (aged 81-89 years), and oldest quartile (aged 90-107 years). RESULTS While the density of NPs and NFTs rose significantly by more than 10-fold as a function of the severity of dementia in the youngest-old group, significant increases in the densities of NPs and NFTs were absent in the brains of the oldest-old. This lack of difference in the densities of NPs and NFTs was due to reduced lesion densities in the brains of oldest-old persons with dementia rather than to increased density of these lesions in the brains of nondemented oldest-old persons. CONCLUSIONS These findings suggest that the neuropathological features of dementia in the oldest-old are not the same as those of cognitively impaired younger-old persons and compel a vigorous search for neuropathological indices of dementia in this most rapidly growing segment of the elderly population.
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Affiliation(s)
- Vahram Haroutunian
- James J. Peters VA Medical Center, 130 W Kingsbridge Rd, Bronx, NY 10468, USA.
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222
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Amyloid beta-peptide levels in laser capture microdissected cornu ammonis 1 pyramidal neurons of Alzheimer's brain. Neuroreport 2008; 19:1085-9. [PMID: 18596605 DOI: 10.1097/wnr.0b013e328302c858] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Deposition of the amyloid beta-peptide (Abeta) is a pathophysiological event associated with Alzheimer's disease. Although much is known about the molecular composition of extracellular Abeta deposits, the role of the intracellular pool of Abeta is not fully understood. We investigated whether Abeta levels are increased in cornu ammonis 1 pyramidal neurons of Alzheimer's disease hippocampus, using laser capture microdissection to isolate the neurons and enzyme-linked immunosorbent assay for quantification. Our results showed increased Abeta42 levels and an elevated Abeta42/Abeta40 ratio in neurons from sporadic as well as from familial cases of Alzheimer's disease, whereas Abeta40 levels remain unchanged between the cases and controls. We speculate that intracellular accumulation of Abeta42 increase vulnerability of cornu ammonis 1 pyramidal neurons in Alzheimer's disease.
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223
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Woltjer RL, Sonnen JA, Sokal I, Rung LG, Yang W, Kjerulf JD, Klingert D, Johnson C, Rhew I, Tsuang D, Crane PK, Larson EB, Montine TJ. Quantitation and mapping of cerebral detergent-insoluble proteins in the elderly. Brain Pathol 2008; 19:365-74. [PMID: 18652590 DOI: 10.1111/j.1750-3639.2008.00190.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Accumulation of abnormal protein aggregates, detergent-insoluble (DI) proteins and amyloid in the brain are shared features of many neurodegenerative diseases. Previous studies correlating DI proteins and cognitive performance are limited. We addressed these limitations using two sets of autopsy brains, one selected from our Alzheimer's Disease Research Center and the other an unselected series from Adult Changes in Thought (ACT), a population-based study of brain aging. We observed concentrations of 11 proteins and 6 protein variants that can be grouped into three highly correlated clusters: amyloid (A)beta, tau and alpha-synuclein (alpha-syn). While abnormal proteins from each cluster independently correlated with cognitive performance in ACT participants, only increased soluble Abeta oligomers in temporal cortex and increased DI Abeta 42 and DI alpha-syn in prefrontal cortex were negatively correlated with cognitive performance. These data underscore the therapeutic imperative to suppress processes leading to accumulation of soluble Abeta oligomers, DI Abeta 42 and DI alpha-syn, highlight an at least partially independent contribution to cognitive impairment and raise the possibility that the priority for therapeutic targets may vary by brain region in a typical elderly US population.
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Affiliation(s)
- Randall L Woltjer
- Department of Pathology Oregon Health Sciences University, Portland, OR 97239-3098, USA.
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224
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Abstract
Aging-related neurodegenerative diseases (NDs) are the culmination of many different genetic and environmental influences. Prior studies have shown that RNAs are pathologically altered during the inexorable course of some NDs. Recent evidence suggests that microRNAs (miRNAs) may be a contributing factor in neurodegeneration. miRNAs are brain-enriched, small ( approximately 22 nucleotides) non-coding RNAs that participate in mRNA translational regulation. Although discovered in the framework of worm development, miRNAs are now appreciated to play a dynamic role in many mammalian brain-related biochemical pathways, including neuroplasticity and stress responses. Research about miRNAs in the context of neurodegeneration is accumulating rapidly, and the goal of this review is to provide perspective for these new data that may be helpful to specialists in either field. An overview is provided about the normal functions for miRNAs, including some of the newer concepts related to the human brain. Recently published studies pertaining to the roles of miRNAs in NDs--including Alzheimer's disease, Parkinson's disease and triplet repeat disorders-are described. Finally, a discussion is included with theoretical syntheses and possible future directions in exploring the nexus between miRNA and ND research.
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Affiliation(s)
- Peter T Nelson
- Department of Pathology, University of Kentucky, Lexington, KY, USA.
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225
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The expression of microRNA miR-107 decreases early in Alzheimer's disease and may accelerate disease progression through regulation of beta-site amyloid precursor protein-cleaving enzyme 1. J Neurosci 2008; 28:1213-23. [PMID: 18234899 DOI: 10.1523/jneurosci.5065-07.2008] [Citation(s) in RCA: 612] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
MicroRNAs (miRNAs) are small regulatory RNAs that participate in posttranscriptional gene regulation in a sequence-specific manner. However, little is understood about the role(s) of miRNAs in Alzheimer's disease (AD). We used miRNA expression microarrays on RNA extracted from human brain tissue from the University of Kentucky Alzheimer's Disease Center Brain Bank with near-optimal clinicopathological correlation. Cases were separated into four groups: elderly nondemented with negligible AD-type pathology, nondemented with incipient AD pathology, mild cognitive impairment (MCI) with moderate AD pathology, and AD. Among the AD-related miRNA expression changes, miR-107 was exceptional because miR-107 levels decreased significantly even in patients with the earliest stages of pathology. In situ hybridization with cross-comparison to neuropathology demonstrated that particular cerebral cortical laminas involved by AD pathology exhibit diminished neuronal miR-107 expression. Computational analysis predicted that the 3'-untranslated region (UTR) of beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) mRNA is targeted multiply by miR-107. From the same RNA material analyzed on miRNA microarrays, mRNA expression profiling was performed using Affymetrix Exon Array microarrays on nondemented, MCI, and AD patients. BACE1 mRNA levels tended to increase as miR-107 levels decreased in the progression of AD. Cell culture reporter assays performed with a subset of the predicted miR-107 binding sites indicate the presence of at least one physiological miR-107 miRNA recognition sequence in the 3'-UTR of BACE1 mRNA. Together, the coordinated application of miRNA profiling, Affymetrix microarrays, new bioinformatics predictions, in situ hybridization, and biochemical validation indicate that miR-107 may be involved in accelerated disease progression through regulation of BACE1.
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226
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Neuropathology--for the living and the future. J Neuropathol Exp Neurol 2007; 66:1057-8. [PMID: 18090914 DOI: 10.1097/nen.0b013e31815d8c10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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