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Jicha GA, Tucker TC, Arnold SM, Nelson PT. Cancer research provides a model for advancing clinical trials in dementia in the era of disease-modifying Alzheimer's-type dementia therapies. Alzheimers Res Ther 2024; 16:184. [PMID: 39164754 PMCID: PMC11337902 DOI: 10.1186/s13195-024-01532-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 07/15/2024] [Indexed: 08/22/2024]
Abstract
Dementia and cancer are multifactorial, widely-feared, age-associated clinical syndromes that are increasing in prevalence. There have been major breakthroughs in clinical cancer research leading to some effective treatments, whereas the field of dementia has achieved comparatively limited success in clinical research. The lessons of cancer research may help those in the dementia research field in confronting some of the dilemmas faced when the clinical care regimen is not entirely safe or efficacious. Cancer clinical trials have assumed that untreated individuals with cancer are at high risk for morbidity and mortality after primary diagnoses. Thus, patients deserve a choice of clinical interventions, either standard of care or experimental, even if the benefits are not certain and the therapy's side effects are potentially severe. The prognosis for many individuals at risk for dementia carries a correspondingly high level of risk for both mortality and severe morbidity, particularly if one focuses on "health-span" rather than lifespan. Caregivers and patients can be strongly impacted by dementia and the many troubling associated symptoms that often go well beyond amnesia. Polls, surveys, and a literature on "dementia worry" strongly underscore that the public fears dementia. While there are institutional and industry hurdles that complicate enrollment in randomized trials, the gravity of the future morbidity and mortality inherent in a dementia diagnosis may require reconsideration of the current protective stance that limits the freedom of at-risk individuals (either symptomatic or asymptomatic) to participate and potentially benefit from ongoing clinical research. There is also evidence from both cancer and dementia research that individuals enrolled in the placebo arms of clinical trials have unexpectedly good outcomes, indicating that participation in clinical trial can have medical benefits to enrollees. To highlight aspects of cancer clinical research that may inform present and future dementia clinical research, this review highlights three main themes: the risk of side effects should be weighed against the often dire consequences of non-treatment; the desirability of long-term incremental (rather than "magic bullet") clinical advances; and, the eventual importance of combination therapies, reflecting that the dementia clinical syndrome has many underlying biological pathways.
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Affiliation(s)
- Gregory A Jicha
- Department of Neurology, University of Kentucky, Lexington, KY, USA
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
| | - Thomas C Tucker
- College of Public Health, University of Kentucky, Lexington, KY, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY, USA
| | - Susanne M Arnold
- Department of Internal Medicine, University of Kentucky, Lexington, KY, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY, USA
| | - Peter T Nelson
- Department of Pathology and Laboratory Medicine, University of Kentucky, Rm 575 Lee Todd Bldg, 789 S. Limestone Ave, Lexington, KY, 40536, USA.
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA.
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Gal J, Vary C, Gartner CA, Jicha GA, Abner EL, Ortega YS, Choucair I, Wilcock DM, Nelson RS, Nelson PT. Exploratory Mass Spectrometry of Cerebrospinal Fluid from Persons with Autopsy-Confirmed LATE-NC. J Mol Neurosci 2024; 74:65. [PMID: 38987361 DOI: 10.1007/s12031-024-02239-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 06/25/2024] [Indexed: 07/12/2024]
Abstract
Common neuropathologies associated with dementia include Alzheimer's disease neuropathologic change (ADNC) and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Biofluid proteomics provides a window into the pathobiology of dementia and the information from biofluid tests may help guide clinical management. Participants (n = 29) had been autopsied and had antemortem CSF draws in a longitudinal cohort of older adults at the University of Kentucky AD Research Center. Cases were designated as LATE-NC + if they had LATE-NC stage > 1 (n = 9); the remaining 20 cases were designated LATE-NC-. This convenience sample of CSF specimens was analyzed in two separate processes: From one group, aliquots were depleted of highly abundant proteins using affinity spin columns. Tryptic digests of sample proteins were subjected to liquid chromatographic separation and mass spectrometry. Relative quantification was performed using Sciex software. Peptides referent to a total of 949 proteins were identified in the samples depleted of abundant proteins, and 820 different proteins were identified in the non-depleted samples. When the Bonferroni/false-discovery statistical correction was applied to account for having made multiple comparison tests, only 4 proteins showed differential expression (LATE-NC + vs LATE-NC-) in the non-depleted samples (RBP4, MIF, IGHG3, and ITM2B). Post hoc western blots confirmed that RBP4 expression was higher in the LATE-NC + cases at the group level. In summary, an exploratory assessment of proteomes of autopsy-confirmed LATE-NC and non-LATE-NC CSF did not demonstrate a clear-cut proteomic fingerprint that distinguished the two groups. There was, however, an increase in RBP4 protein levels in CSF from LATE-NC cases.
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Affiliation(s)
- Jozsef Gal
- Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, KY, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Calvin Vary
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Carlos A Gartner
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Gregory A Jicha
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- Department of Neurology, University of Kentucky, Lexington, KY, USA
| | - Erin L Abner
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- School of Public Health, University of Kentucky, Lexington, KY, USA
| | - Yulica S Ortega
- Center for Molecular Medicine, MaineHealth Institute for Research, Scarborough, ME, USA
| | - Ibrahim Choucair
- Department of Pathology and Laboratory Medicine, University of Kentucky, Rm 575 Todd Building, Lexington, KY, 40536, USA
| | - Donna M Wilcock
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA
- University of Indiana, Indianapolis, IN, USA
| | | | - Peter T Nelson
- Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, USA.
- Department of Pathology and Laboratory Medicine, University of Kentucky, Rm 575 Todd Building, Lexington, KY, 40536, USA.
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Chung M, Carter EK, Veire AM, Dammer EB, Chang J, Duong DM, Raj N, Bassell GJ, Glass JD, Gendron TF, Nelson PT, Levey AI, Seyfried NT, McEachin ZT. Cryptic exon inclusion is a molecular signature of LATE-NC in aging brains. Acta Neuropathol 2024; 147:29. [PMID: 38308693 PMCID: PMC10838224 DOI: 10.1007/s00401-023-02671-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/30/2023] [Accepted: 12/17/2023] [Indexed: 02/05/2024]
Abstract
The aggregation, mislocalization, and phosphorylation of TDP-43 are pathologic hallmarks of several neurodegenerative diseases and provide a defining criterion for the neuropathologic diagnosis of Limbic-predominant Age-related TDP-43 Encephalopathy (LATE). LATE neuropathologic changes (LATE-NC) are often comorbid with other neurodegenerative pathologies including Alzheimer's disease neuropathologic changes (ADNC). We examined whether TDP-43 regulated cryptic exons accumulate in the hippocampus of neuropathologically confirmed LATE-NC cases. We found that several cryptic RNAs are robustly expressed in LATE-NC cases with or without comorbid ADNC and correlate with pTDP-43 abundance; however, the accumulation of cryptic RNAs is more robust in LATE-NC with comorbid ADNC. Additionally, cryptic RNAs can robustly distinguish LATE-NC from healthy controls and AD cases. These findings expand our current understanding and provide novel potential biomarkers for LATE pathogenesis.
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Affiliation(s)
- Mingee Chung
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - E Kathleen Carter
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Austin M Veire
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Jianjun Chang
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA
| | - Nisha Raj
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Department of Human Genetics, Emory University, Atlanta, GA, 30322, USA
| | - Gary J Bassell
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA
| | - Jonathan D Glass
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA
| | - Tania F Gendron
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Peter T Nelson
- Department of Pathology and Sanders-Brown Center On Aging, University of Kentucky, Lexington, KY, 40536, USA
| | - Allan I Levey
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
- Department of Neurology, Emory University, Atlanta, GA, 30322, USA.
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
| | - Zachary T McEachin
- Department of Cell Biology, Emory University, Atlanta, GA, 30322, USA.
- Laboratory for Translational Cell Biology, Emory University, Atlanta, GA, 30322, USA.
- Department of Human Genetics, Emory University, Atlanta, GA, 30322, USA.
- Center for Neurodegenerative Diseases, Emory University, Atlanta, GA, 30322, USA.
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Katsumata Y, Wu X, Aung KZ, Gauthreaux K, Mock C, Forrest SL, Kovacs GG, Nelson PT. Pathologic correlates of aging-related tau astrogliopathy: ARTAG is associated with LATE-NC and cerebrovascular pathologies, but not with ADNC. Neurobiol Dis 2024; 191:106412. [PMID: 38244935 PMCID: PMC10892903 DOI: 10.1016/j.nbd.2024.106412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024] Open
Abstract
Age-related tau astrogliopathy (ARTAG) is detectable in the brains of over one-third of autopsied persons beyond age 80, but the pathoetiology of ARTAG is poorly understood. Insights can be gained by analyzing risk factors and comorbid pathologies. Here we addressed the question of which prevalent co-pathologies are observed with increased frequency in brains with ARTAG. The study sample was the National Alzheimer's Coordinating Center (NACC) data set, derived from multiple Alzheimer's disease research centers (ADRCs) in the United States. Data from persons with unusual conditions (e.g. frontotemporal dementia) were excluded leaving 504 individual autopsied research participants, clustering from 20 different ADRCs, autopsied since 2020; ARTAG was reported in 222 (44.0%) of included participants. As has been shown previously, ARTAG was increasingly frequent with older age and in males. The presence and severity of other common subtypes of pathology that were previously linked to dementia were analyzed, stratifying for the presence of ARTAG. In logistical regression-based statistical models that included age and sex as covariates, ARTAG was relatively more likely to be found in brains with limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and in brains with comorbid cerebrovascular pathology (arteriolosclerosis and/or brain infarcts). However, ARTAG was not associated with severe Alzheimer's disease neuropathologic change (ADNC), or primary age-related tauopathy (PART). In a subset analysis of 167 participants with neurocognitive testing data, there was a marginal trend for ARTAG pathology to be associated with cognitive impairment as assessed with MMSE scores (P = 0.07, adjusting for age, sex, interval between final clinic visit and death, and ADNC severity). A limitation of the study was that there were missing data about ARTAG pathologies, with incomplete operationalization of ARTAG according to anatomic region and pathologic subtypes (e.g., thorn-shaped or granular-fuzzy astrocytes). In summary, ARTAG was not associated with ADNC, whereas prior observations about ARTAG occurring with increased frequency in aging, males, and brains with LATE-NC were replicated. It remains to be determined whether the increased frequency of ARTAG in brains with comorbid cerebrovascular pathology is related to local infarctions or neuroinflammatory signaling, or with some other set of correlated factors including blood-brain barrier dysfunction.
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Affiliation(s)
- Yuriko Katsumata
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, United States of America; Department of Biostatistics, University of Kentucky, Lexington, KY 40506, United States of America
| | - Xian Wu
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, United States of America; Department of Biostatistics, University of Kentucky, Lexington, KY 40506, United States of America
| | - Khine Zin Aung
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, United States of America; Department of Biostatistics, University of Kentucky, Lexington, KY 40506, United States of America
| | - Kathryn Gauthreaux
- National Alzheimer's Coordinating Center, Department of Epidemiology, University of Washington, Seattle, WA 98105, United States of America
| | - Charles Mock
- National Alzheimer's Coordinating Center, Department of Epidemiology, University of Washington, Seattle, WA 98105, United States of America
| | - Shelley L Forrest
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, Canada; Laboratory Medicine Program and Krembil Brain Institute, University Health Network, Toronto, Canada
| | - Gabor G Kovacs
- Tanz Centre for Research in Neurodegenerative Disease, University of Toronto, Toronto, Canada; Laboratory Medicine Program and Krembil Brain Institute, University Health Network, Toronto, Canada
| | - Peter T Nelson
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506, United States of America; Department of Pathology, Division of Neuropathology, University of Kentucky, Lexington, KY, United States of America.
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Niedowicz DM, Katsumata Y, Nelson PT. In severe ADNC, hippocampi with comorbid LATE-NC and hippocampal sclerosis have substantially more astrocytosis than those with LATE-NC or hippocampal sclerosis alone. J Neuropathol Exp Neurol 2023; 82:987-994. [PMID: 37935530 PMCID: PMC10658353 DOI: 10.1093/jnen/nlad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023] Open
Abstract
Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) and hippocampal sclerosis of aging (HS-A) pathologies are found together at autopsy in ∼20% of elderly demented persons. Although astrocytosis is known to occur in neurodegenerative diseases, it is currently unknown how the severity of astrocytosis is correlated with the common combinations of pathologies in aging brains. To address this knowledge gap, we analyzed a convenience sample of autopsied subjects from the University of Kentucky Alzheimer's Disease Research Center community-based autopsy cohort. The subjects were stratified into 5 groups (n = 51 total): pure ADNC, ADNC + LATE-NC, ADNC + HS-A, ADNC + LATE-NC + HS-A, and low-pathology controls. Following GFAP immunostaining and digital slide scanning with a ScanScope, we measured GFAP-immunoreactive astrocytosis. The severities of GFAP-immunoreactive astrocytosis in hippocampal subfield CA1 and subiculum were compared between groups. The group with ADNC + LATE-NC + HS-A had the most astrocytosis as operationalized by either any GFAP+ or strong GFAP+ immunoreactivity in both CA1 and subiculum. In comparison to that pathologic combination, ADNC + HS or ADNC + LATE-NC alone showed lower astrocytosis. Pure ADNC had only marginally increased astrocytosis in CA1 and subiculum, in comparison to low-pathology controls. We conclude that there appeared to be pathogenetic synergy such that ADNC + LATE-NC + HS-A cases had relatively high levels of astrocytosis in the hippocampal formation.
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Gal J, Vary C, Gartner CA, Jicha GA, Abner EL, Ortega YS, Choucair I, Wilcock DM, Nelson R, Nelson P. Exploratory mass spectrometry of cerebrospinal fluid from persons with autopsy-confirmed LATE-NC. RESEARCH SQUARE 2023:rs.3.rs-3252238. [PMID: 37674727 PMCID: PMC10479397 DOI: 10.21203/rs.3.rs-3252238/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Background Common neuropathologies associated with dementia include Alzheimer's disease neuropathologic change (ADNC) and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC). Biofluid proteomics provides a window into the pathobiology of dementia and the information from biofluid tests may help guide clinical management. Methods Participants were recruited from a longitudinal cohort of older adults at the University of Kentucky AD Research Center. A convenience sample of clinically obtained lumbar puncture cerebrospinal fluid (CSF) samples was analyzed from 29 older adults that had autopsy confirmation of the presence or absence of LATE-NC. Nine of the participants had autopsy-confirmed LATE-NC. Antemortem CSF specimens were analyzed in two separate processes: From one group, aliquots were depleted of highly abundant proteins using affinity spin columns. Tryptic digests of sample proteins were subjected to liquid chromatographic separation and mass spectrometry using an Eksigent Ekspert nanoLC 400 system in line with a Sciex 6600+ mass spectrometer. Protein identification was performed using Protein Pilot (Sciex, ver. 5) software, and relative quantification was performed using the SWATH processing microApp in PeakView and MarkerView software (Sciex), respectively. Following data analyses, additional studies were performed using western blots. Results A total of 830 proteins were identified in the samples depleted of abundant proteins, and 730 proteins were identified in the non-depleted samples. Whereas some dementia-related proteins were detected (Aβ peptide and α-synuclein protein), others were not (TDP-43, TMEM106B, and tau proteins). When the Bonferroni correction was applied to correct for multiple comparisons, only 4 proteins showed differential expression (LATE-NC vs non-LATE-NC) in the nondepleted samples (RBP4, MIF, IGHG3 and ITM2B), whereas none showed statistically different changes in the depleted samples. Post-hoc western blots confirmed that RBP4 expression was higher in the LATE-NC cases at the group level, but there was overlap between the levels of RBP4 in LATE-NC and non-LATE-NC cases. Conclusions An exploratory assessment of CSF proteomes of autopsy-confirmed LATE-NC and non-LATE-NC cases from a community-based cohort failed to demonstrate a clear-cut proteomic fingerprint that distinguished the two groups. There was intriguing increase in RBP4 protein levels in CSF from LATE-NC cases. This may provide clues about pathogenetic mechanisms in LATE-NC.
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