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Lista S, Imbimbo BP, Grasso M, Fidilio A, Emanuele E, Minoretti P, López-Ortiz S, Martín-Hernández J, Gabelle A, Caruso G, Malaguti M, Melchiorri D, Santos-Lozano A, Imbimbo C, Heneka MT, Caraci F. Tracking neuroinflammatory biomarkers in Alzheimer's disease: a strategy for individualized therapeutic approaches? J Neuroinflammation 2024; 21:187. [PMID: 39080712 PMCID: PMC11289964 DOI: 10.1186/s12974-024-03163-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 06/28/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Recent trials of anti-amyloid-β (Aβ) monoclonal antibodies, including lecanemab and donanemab, in early Alzheimer disease (AD) showed that these drugs have limited clinical benefits and their use comes with a significant risk of serious adverse events. Thus, it seems crucial to explore complementary therapeutic approaches. Genome-wide association studies identified robust associations between AD and several AD risk genes related to immune response, including but not restricted to CD33 and TREM2. Here, we critically reviewed the current knowledge on candidate neuroinflammatory biomarkers and their role in characterizing the pathophysiology of AD. MAIN BODY Neuroinflammation is recognized to be a crucial and contributing component of AD pathogenesis. The fact that neuroinflammation is most likely present from earliest pre-stages of AD and co-occurs with the deposition of Aβ reinforces the need to precisely define the sequence and nature of neuroinflammatory events. Numerous clinical trials involving anti-inflammatory drugs previously yielded unfavorable outcomes in early and mild-to-moderate AD. Although the reasons behind these failures remain unclear, these may include the time and the target selected for intervention. Indeed, in our review, we observed a stage-dependent neuroinflammatory process in the AD brain. While the initial activation of glial cells counteracts early brain Aβ deposition, the downregulation in the functional state of microglia occurs at more advanced disease stages. To address this issue, personalized neuroinflammatory modulation therapy is required. The emergence of reliable blood-based neuroinflammatory biomarkers, particularly glial fibrillary acidic protein, a marker of reactive astrocytes, may facilitate the classification of AD patients based on the ATI(N) biomarker framework. This expands upon the traditional classification of Aβ ("A"), tau ("T"), and neurodegeneration ("N"), by incorporating a novel inflammatory component ("I"). CONCLUSIONS The present review outlines the current knowledge on potential neuroinflammatory biomarkers and, importantly, emphasizes the role of longitudinal analyses, which are needed to accurately monitor the dynamics of cerebral inflammation. Such a precise information on time and place will be required before anti-inflammatory therapeutic interventions can be considered for clinical evaluation. We propose that an effective anti-neuroinflammatory therapy should specifically target microglia and astrocytes, while considering the individual ATI(N) status of patients.
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Affiliation(s)
- Simone Lista
- i+HeALTH Strategic Research Group, Department of Health Sciences, Miguel de Cervantes European University (UEMC), 47012, Valladolid, Spain.
| | - Bruno P Imbimbo
- Department of Research and Development, Chiesi Farmaceutici, 43122, Parma, Italy
| | | | | | | | | | - Susana López-Ortiz
- i+HeALTH Strategic Research Group, Department of Health Sciences, Miguel de Cervantes European University (UEMC), 47012, Valladolid, Spain
| | - Juan Martín-Hernández
- i+HeALTH Strategic Research Group, Department of Health Sciences, Miguel de Cervantes European University (UEMC), 47012, Valladolid, Spain
| | - Audrey Gabelle
- CMRR, Memory Resources and Research Center, Montpellier University of Excellence i-site, 34295, Montpellier, France
| | - Giuseppe Caruso
- Oasi Research Institute-IRCCS, 94018, Troina, Italy
- Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy
| | - Marco Malaguti
- Department for Life Quality Studies, Alma Mater Studiorum, University of Bologna, 40126, Bologna, Italy
| | - Daniela Melchiorri
- Department of Physiology and Pharmacology, Sapienza University, 00185, Rome, Italy
| | - Alejandro Santos-Lozano
- i+HeALTH Strategic Research Group, Department of Health Sciences, Miguel de Cervantes European University (UEMC), 47012, Valladolid, Spain
- Physical Activity and Health Research Group (PaHerg), Research Institute of the Hospital, 12 de Octubre ('imas12'), 28041, Madrid, Spain
| | - Camillo Imbimbo
- Department of Brain and Behavioral Sciences, University of Pavia, 27100, Pavia, Italy
| | - Michael T Heneka
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 4367, Esch-Belval, Luxembourg.
| | - Filippo Caraci
- Oasi Research Institute-IRCCS, 94018, Troina, Italy.
- Department of Drug and Health Sciences, University of Catania, 95125, Catania, Italy.
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Nabizadeh F, Seyedmirzaei H, Karami S. Neuroimaging biomarkers and CSF sTREM2 levels in Alzheimer's disease: a longitudinal study. Sci Rep 2024; 14:15318. [PMID: 38961148 PMCID: PMC11222555 DOI: 10.1038/s41598-024-66211-w] [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: 10/27/2023] [Accepted: 06/28/2024] [Indexed: 07/05/2024] Open
Abstract
Understanding the exact pathophysiological mechanisms underlying the involvement of triggering receptor expressed on myeloid cells 2 (TREM2) related microglia activation is crucial for the development of clinical trials targeting microglia activation at different stages of Alzheimer's disease (AD). Given the contradictory findings in the literature, it is imperative to investigate the longitudinal alterations in cerebrospinal fluid (CSF) soluble TREM2 (sTREM2) levels as a marker for microglia activation, and its potential association with AD biomarkers, in order to address the current knowledge gap. In this study, we aimed to assess the longitudinal changes in CSF sTREM2 levels within the framework of the A/T/N classification system for AD biomarkers and to explore potential associations with AD pathological features, including the presence of amyloid-beta (Aβ) plaques and tau aggregates. The baseline and longitudinal (any available follow-up visit) CSF sTREM2 levels and processed tau-PET and Aβ-PET data of 1001 subjects were recruited from the ADNI database. The participants were classified into four groups based on the A/T/N framework: A+ /TN+ , A+ /TN- , A- /TN+ , and A- /TN- . Linear regression analyses were conducted to assess the relationship between CSF sTREM2 with cognitive performance, tau and Aβ-PET adjusting for age, gender, education, and APOE ε4 status. Based on our analysis there was a significant difference in baseline and rate of change of CSF sTREM2 between ATN groups. While there was no association between baseline CSF sTREM2 and cognitive performance (ADNI-mem), we found that the rate of change of CSF sTREM2 is significantly associated with cognitive performance in the entire cohort but not the ATN groups. We found that the baseline CSF sTREM2 is significantly associated with baseline tau-PET and Aβ-PET rate of change only in the A+ /TN+ group. A significant association was found between the rate of change of CSF sTREM2 and the tau- and Aβ-PET rate of change only in the A+ /TN- group. Our study suggests that the TREM2-related microglia activation and their relations with AD markers and cognitive performance vary the in presence or absence of Aβ and tau pathology. Furthermore, our findings revealed that a faster increase in the level of CSF sTREM2 might attenuate future Aβ plaque formation and tau aggregate accumulation only in the presence of Aβ pathology.
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Affiliation(s)
- Fardin Nabizadeh
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
- Alzheimer's Disease Institute, Tehran, Iran.
| | - Homa Seyedmirzaei
- School of Medicine, Tehran University of Medical Science, Tehran, Iran
- Interdisciplinary Neuroscience Research Program (INRP), Tehran University of Medical Sciences, Tehran, Iran
| | - Shaghayegh Karami
- School of Medicine, Tehran University of Medical Science, Tehran, Iran
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3
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Wang R, Zhan Y, Zhu W, Yang Q, Pei J. Association of soluble TREM2 with Alzheimer's disease and mild cognitive impairment: a systematic review and meta-analysis. Front Aging Neurosci 2024; 16:1407980. [PMID: 38841103 PMCID: PMC11150578 DOI: 10.3389/fnagi.2024.1407980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/03/2024] [Indexed: 06/07/2024] Open
Abstract
Objective Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) is a potential neuroinflammatory biomarker linked to the pathogenesis of Alzheimer's disease (AD) and mild cognitive impairment (MCI). Previous studies have produced inconsistent results regarding sTREM2 levels in various clinical stages of AD. This study aims to establish the correlation between sTREM2 levels and AD progression through a meta-analysis of sTREM2 levels in cerebrospinal fluid (CSF) and blood. Methods Comprehensive searches were conducted in PubMed, Embase, Web of Science, and the Cochrane Library to identify observational studies reporting CSF and blood sTREM2 levels in AD patients, MCI patients, and healthy controls. A random effects meta-analysis was used to calculate the standardized mean difference (SMD) and 95% confidence intervals (CIs). Results Thirty-six observational studies involving 3,016 AD patients, 3,533 MCI patients, and 4,510 healthy controls were included. CSF sTREM2 levels were significantly higher in both the AD [SMD = 0.28, 95% CI (0.15, 0.41)] and MCI groups [SMD = 0.30, 95% CI (0.13, 0.47)] compared to the healthy control group. However, no significant differences in expression were detected between the AD and MCI groups [SMD = 0.09, 95% CI (-0.09, 0.26)]. Furthermore, increased plasma sTREM2 levels were associated with a higher risk of AD [SMD = 0.42, 95% CI (0.01, 0.83)]. Conclusion CSF sTREM2 levels are positively associated with an increased risk of AD and MCI. Plasma sTREM2 levels were notably higher in the AD group than in the control group and may serve as a promising biomarker for diagnosing AD. However, sTREM2 levels are not effective for distinguishing between different disease stages of AD. Further investigations are needed to explore the longitudinal changes in sTREM2 levels, particularly plasma sTREM2 levels, during AD progression. Systematic review registration https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024514593.
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Affiliation(s)
| | | | | | | | - Jian Pei
- Department of Acupuncture, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Winfree RL, Nolan E, Dumitrescu L, Blennow K, Zetterberg H, Gifford KA, Pechman KR, Seto M, Petyuk VA, Wang Y, Schneider J, Bennett DA, Jefferson AL, Hohman TJ. Variants in the MS4A cluster interact with soluble TREM2 expression on biomarkers of neuropathology. Mol Neurodegener 2024; 19:41. [PMID: 38760857 PMCID: PMC11101336 DOI: 10.1186/s13024-024-00727-7] [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: 08/04/2023] [Accepted: 04/11/2024] [Indexed: 05/19/2024] Open
Abstract
Recent evidence suggests that Alzheimer's disease (AD) genetic risk variants (rs1582763 and rs6591561) of the MS4A locus are genome-wide significant regulators of soluble TREM2 levels such that the minor allele of the protective variant (rs1582763) is associated with higher sTREM2 and lower AD risk while the minor allele of (rs6591561) relates to lower sTREM2 and higher AD risk. Our group previously found that higher sTREM2 relates to higher Aβ40, worse blood-brain barrier (BBB) integrity (measured with the CSF/plasma albumin ratio), and higher CSF tau, suggesting strong associations with amyloid abundance and both BBB and neurodegeneration complicate interpretation. We expand on this work by leveraging these common variants as genetic tools to tune the interpretation of high CSF sTREM2, and by exploring the potential modifying role of these variants on the well-established associations between CSF sTREM2 as well as TREM2 transcript levels in the brain with AD neuropathology. Biomarker analyses leveraged data from the Vanderbilt Memory & Aging Project (n = 127, age = 72 ± 6.43) and were replicated in the Alzheimer's Disease Neuroimaging Initiative (n = 399, age = 73 ± 7.39). Autopsy analyses were performed leveraging data from the Religious Orders Study and Rush Memory and Aging Project (n = 577, age = 89 ± 6.46). We found that the protective variant rs1582763 attenuated the association between CSF sTREM2 and Aβ40 (β = -0.44, p-value = 0.017) and replicated this interaction in ADNI (β = -0.27, p = 0.017). We did not observe this same interaction effect between TREM2 mRNA levels and Aβ peptides in brain (Aβ total β = -0.14, p = 0.629; Aβ1-38, β = 0.11, p = 0.200). In contrast to the effects on Aβ, the minor allele of this same variant seemed to enhance the association with blood-brain barrier dysfunction (β = 7.0e-4, p = 0.009), suggesting that elevated sTREM2 may carry a much different interpretation in carriers vs. non-carriers of this allele. When evaluating the risk variant (rs6591561) across datasets, we did not observe a statistically significant interaction against any outcome in VMAP and observed opposing directions of associations in ADNI and ROS/MAP on Aβ levels. Together, our results suggest that the protective effect of rs1582763 may act by decoupling the associations between sTREM2 and amyloid abundance, providing important mechanistic insight into sTREM2 changes and highlighting the need to incorporate genetic context into the analysis of sTREM2 levels, particularly if leveraged as a clinical biomarker of disease in the future.
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Affiliation(s)
- Rebecca L Winfree
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA.
- Pharmacology Department, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Emma Nolan
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Epidemiology Doctoral Program, School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - Logan Dumitrescu
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 431 41, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 431 41, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine A Gifford
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kimberly R Pechman
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Mabel Seto
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Vladislav A Petyuk
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Yanling Wang
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Julie Schneider
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
- Department of Pathology, Rush University Medical Center, Chicago, IL, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Angela L Jefferson
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy J Hohman
- Vanderbilt Memory and Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Pharmacology Department, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
- Epidemiology Doctoral Program, School of Medicine, Vanderbilt University, Nashville, TN, USA
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5
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Süße M, Kloetzer C, Strauß S, Ruhnau J, Overeem LH, Bendig M, Schulze J, Reuter U, Vogelgesang A, Fleischmann R. Increased CX3CL1 in cerebrospinal fluid and ictal serum t-tau elevations in migraine: results from a cross-sectional exploratory case-control study. J Headache Pain 2024; 25:46. [PMID: 38561692 PMCID: PMC10985871 DOI: 10.1186/s10194-024-01757-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/24/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND To date, migraine is diagnosed exclusively based on clinical criteria, but fluid biomarkers are desirable to gain insight into pathophysiological processes and inform clinical management. We investigated the state-dependent profile of fluid biomarkers for neuroaxonal damage and microglial activation as two potentially relevant aspects in human migraine pathophysiology. METHODS This exploratory study included serum and cerebrospinal fluid (CSF) samples of patients with migraine during the headache phase (ictally) (n = 23), between attacks (interictally) (n = 16), and age/sex-matched controls (n = 19). Total Tau (t-Tau) protein, glial fibrillary acidic protein (GFAP), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), and neurofilament light chain (NfL) were measured with the Neurology 4-plex kit on a Single Molecule Array SR-X Analyzer (Simoa® SR-X, Quanterix Corp., Lexington, MA). Markers of microglial activation, C-X3-C motif chemokine ligand 1 (CX3CL1) and soluble triggering receptor expressed on myeloid cells 2 (sTREM2), were assessed using an immunoassay. RESULTS Concentrations of CX3CL1 but not sTREM2 were significantly increased both ictally and interictally in CSF but not in serum in comparison to the control cohort (p = 0.039). ROC curve analysis provided an AUC of 0.699 (95% CI 0.563 to 0.813, p = 0.007). T-Tau in serum but not in CSF was significantly increased in samples from patients taken during the headache phase, but not interictally (effect size: η2 = 0.121, p = 0.038). ROC analysis of t-Tau protein in serum between ictal and interictal collected samples provided an AUC of 0.729 (95% CI 0.558 to 0.861, p = 0.006). The other determined biomarkers for axonal damage were not significantly different between the cohorts in either serum or CSF. DISCUSSION CX3CL1 in CSF is a novel potential fluid biomarker of migraine that is unrelated to the headache status. Serum t-Tau is linked to the headache phase but not interictal migraine. These data need to be confirmed in a larger hypothesis-driven prospective study.
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Affiliation(s)
- Marie Süße
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany.
| | - Christine Kloetzer
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Sebastian Strauß
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Johanna Ruhnau
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Lucas Hendrik Overeem
- Department of Neurology With Experimental Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
- International Graduate Program Medical Neurosciences, Humboldt Graduate School, 10117, Berlin, Germany
| | - Merle Bendig
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Juliane Schulze
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Uwe Reuter
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
- Department of Neurology With Experimental Neurology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Antje Vogelgesang
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
| | - Robert Fleischmann
- Department of Neurology, University Medicine Greifswald, Ferdinand-Sauerbruch-Str. 1, 17475, Greifswald, Germany
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6
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Wang L, Nykänen NP, Western D, Gorijala P, Timsina J, Li F, Wang Z, Ali M, Yang C, Liu M, Brock W, Marquié M, Boada M, Alvarez I, Aguilar M, Pastor P, Ruiz A, Puerta R, Orellana A, Rutledge J, Oh H, Greicius MD, Le Guen Y, Perrin RJ, Wyss-Coray T, Jefferson A, Hohman TJ, Graff-Radford N, Mori H, Goate A, Levin J, Sung YJ, Cruchaga C. Proteo-genomics of soluble TREM2 in cerebrospinal fluid provides novel insights and identifies novel modulators for Alzheimer's disease. Mol Neurodegener 2024; 19:1. [PMID: 38172904 PMCID: PMC10763080 DOI: 10.1186/s13024-023-00687-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 11/28/2023] [Indexed: 01/05/2024] Open
Abstract
Triggering receptor expressed on myeloid cells 2 (TREM2) plays a critical role in microglial activation, survival, and apoptosis, as well as in Alzheimer's disease (AD) pathogenesis. We previously reported the MS4A locus as a key modulator for soluble TREM2 (sTREM2) in cerebrospinal fluid (CSF). To identify additional novel genetic modifiers of sTREM2, we performed the largest genome-wide association study (GWAS) and identified four loci for CSF sTREM2 in 3,350 individuals of European ancestry. Through multi-ethnic fine mapping, we identified two independent missense variants (p.M178V in MS4A4A and p.A112T in MS4A6A) that drive the association in MS4A locus and showed an epistatic effect for sTREM2 levels and AD risk. The novel TREM2 locus on chr 6 contains two rare missense variants (rs75932628 p.R47H, P=7.16×10-19; rs142232675 p.D87N, P=2.71×10-10) associated with sTREM2 and AD risk. The third novel locus in the TGFBR2 and RBMS3 gene region (rs73823326, P=3.86×10-9) included a regulatory variant with a microglia-specific chromatin loop for the promoter of TGFBR2. Using cell-based assays we demonstrate that overexpression and knock-down of TGFBR2, but not RBMS3, leads to significant changes of sTREM2. The last novel locus is located on the APOE region (rs11666329, P=2.52×10-8), but we demonstrated that this signal was independent of APOE genotype. This signal colocalized with cis-eQTL of NECTIN2 in the brain cortex and cis-pQTL of NECTIN2 in CSF. Overexpression of NECTIN2 led to an increase of sTREM2 supporting the genetic findings. To our knowledge, this is the largest study to date aimed at identifying genetic modifiers of CSF sTREM2. This study provided novel insights into the MS4A and TREM2 loci, two well-known AD risk genes, and identified TGFBR2 and NECTIN2 as additional modulators involved in TREM2 biology.
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Affiliation(s)
- Lihua Wang
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Niko-Petteri Nykänen
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Daniel Western
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Priyanka Gorijala
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Jigyasha Timsina
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Fuhai Li
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Zhaohua Wang
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Muhammad Ali
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Chengran Yang
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Menghan Liu
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - William Brock
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
| | - Marta Marquié
- Networking Research Center on Neurodegenerative Disease (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Research Center and Memory Clinic, ACE Alzheimer Center Barcelona, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Mercè Boada
- Networking Research Center on Neurodegenerative Disease (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Research Center and Memory Clinic, ACE Alzheimer Center Barcelona, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Ignacio Alvarez
- Memory Disorders Unit, Department of Neurology, University Hospital Mutua Terrassa, Terrassa, Spain
| | - Miquel Aguilar
- Memory Disorders Unit, Department of Neurology, University Hospital Mutua Terrassa, Terrassa, Spain
| | - Pau Pastor
- Unit of Neurodegenerative diseases, Department of Neurology, University Hospital Germans Trias i Pujol and The Germans Trias i Pujol Research Institute (IGTP) Badalona, Barcelona, Spain
| | - Agustín Ruiz
- Networking Research Center on Neurodegenerative Disease (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Research Center and Memory Clinic, ACE Alzheimer Center Barcelona, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Raquel Puerta
- Networking Research Center on Neurodegenerative Disease (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Research Center and Memory Clinic, ACE Alzheimer Center Barcelona, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Adelina Orellana
- Networking Research Center on Neurodegenerative Disease (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
- Research Center and Memory Clinic, ACE Alzheimer Center Barcelona, Universitat Internacional de Catalunya, Barcelona, Spain
| | - Jarod Rutledge
- Wu-Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Hamilton Oh
- Wu-Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | | | - Yann Le Guen
- Wu-Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Richard J Perrin
- Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Tony Wyss-Coray
- Wu-Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
| | - Angela Jefferson
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy J Hohman
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | | | - Alison Goate
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Johannes Levin
- Department of Neurology, University Hospital of Munich, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Yun Ju Sung
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA
- Division of Biostatistics, Washington University School of Medicine, BJC Institute of Health, 425 S. Euclid Ave, Box 8134, St. Louis, MO, 63110, USA
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA.
- NeuroGenomics and Informatics Center, Washington University School of Medicine, St. Louis, MO, USA.
- Hope Center for Neurologic Diseases, Washington University, St. Louis, MO, USA.
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Alkhalifa AE, Al-Ghraiybah NF, Odum J, Shunnarah JG, Austin N, Kaddoumi A. Blood-Brain Barrier Breakdown in Alzheimer's Disease: Mechanisms and Targeted Strategies. Int J Mol Sci 2023; 24:16288. [PMID: 38003477 PMCID: PMC10671257 DOI: 10.3390/ijms242216288] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
The blood-brain barrier (BBB) is a unique and selective feature of the central nervous system's vasculature. BBB dysfunction has been observed as an early sign of Alzheimer's Disease (AD) before the onset of dementia or neurodegeneration. The intricate relationship between the BBB and the pathogenesis of AD, especially in the context of neurovascular coupling and the overlap of pathophysiology in neurodegenerative and cerebrovascular diseases, underscores the urgency to understand the BBB's role more deeply. Preserving or restoring the BBB function emerges as a potentially promising strategy for mitigating the progression and severity of AD. Molecular and genetic changes, such as the isoform ε4 of apolipoprotein E (ApoEε4), a significant genetic risk factor and a promoter of the BBB dysfunction, have been shown to mediate the BBB disruption. Additionally, receptors and transporters like the low-density lipoprotein receptor-related protein 1 (LRP1), P-glycoprotein (P-gp), and the receptor for advanced glycation end products (RAGEs) have been implicated in AD's pathogenesis. In this comprehensive review, we endeavor to shed light on the intricate pathogenic and therapeutic connections between AD and the BBB. We also delve into the latest developments and pioneering strategies targeting the BBB for therapeutic interventions, addressing its potential as a barrier and a carrier. By providing an integrative perspective, we anticipate paving the way for future research and treatments focused on exploiting the BBB's role in AD pathogenesis and therapy.
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Affiliation(s)
| | | | | | | | | | - Amal Kaddoumi
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, 720 S. Donahue Dr., Auburn, AL 36849, USA; (A.E.A.); (N.F.A.-G.); (J.O.); (J.G.S.); (N.A.)
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Schlepckow K, Morenas-Rodríguez E, Hong S, Haass C. Stimulation of TREM2 with agonistic antibodies-an emerging therapeutic option for Alzheimer's disease. Lancet Neurol 2023; 22:1048-1060. [PMID: 37863592 DOI: 10.1016/s1474-4422(23)00247-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/29/2023] [Accepted: 06/29/2023] [Indexed: 10/22/2023]
Abstract
Neurodegenerative disorders, including Alzheimer's disease, are associated with microgliosis. Microglia have long been considered to have detrimental roles in Alzheimer's disease. However, functional analyses of genes encoding risk factors that are linked to late-onset Alzheimer's disease, and that are enriched or exclusively expressed in microglia, have revealed unexpected protective functions. One of the major risk genes for Alzheimer's disease is TREM2. Risk variants of TREM2 are loss-of-function mutations affecting chemotaxis, phagocytosis, lipid and energy metabolism, and survival and proliferation. Agonistic anti-TREM2 antibodies have been developed to boost these protective functions in patients with intact TREM2 alleles. Several anti-TREM2 antibodies are in early clinical trials, and current efforts aim to achieve more efficient transport of these antibodies across the blood-brain barrier. PET imaging could be used to monitor target engagement. Data from animal models, and biomarker studies in patients, further support a rationale for boosting TREM2 functions during the preclinical stage of Alzheimer's disease.
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Affiliation(s)
- Kai Schlepckow
- German Centre for Neurodegenerative Diseases, Munich, Germany
| | - Estrella Morenas-Rodríguez
- Memory Unit, Department of Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain; Group of Neurogenerative Diseases, Hospital Universitario 12 de Octubre Research Institute (imas12), Madrid, Spain
| | - Soyon Hong
- UK Dementia Research Institute, Institute of Neurology, University College London, London, UK
| | - Christian Haass
- German Centre for Neurodegenerative Diseases, Munich, Germany; Metabolic Biochemistry, Biomedical Centre, Faculty of Medicine, Ludwig-Maximilians University, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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Španić Popovački E, Babić Leko M, Langer Horvat L, Brgić K, Vogrinc Ž, Boban M, Klepac N, Borovečki F, Šimić G. Soluble TREM2 Concentrations in the Cerebrospinal Fluid Correlate with the Severity of Neurofibrillary Degeneration, Cognitive Impairment, and Inflammasome Activation in Alzheimer's Disease. Neurol Int 2023; 15:842-856. [PMID: 37489359 PMCID: PMC10366813 DOI: 10.3390/neurolint15030053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/21/2023] [Accepted: 07/05/2023] [Indexed: 07/26/2023] Open
Abstract
BACKGROUND Individuals with specific TREM2 gene variants that encode for a Triggering Receptor Expressed on Myeloid cells 2 have a higher prevalence of Alzheimer's disease (AD). By interacting with amyloid and apolipoproteins, the TREM2 receptor regulates the number of myeloid cells, phagocytosis, and the inflammatory response. Higher TREM2 expression has been suggested to protect against AD. However, it is extremely difficult to comprehend TREM2 signaling in the context of AD. Previous results are variable and show distinct effects on diverse pathological changes in AD, differences between soluble and membrane isoform signaling, and inconsistency between animal models and humans. In addition, the relationship between TREM2 and inflammasome activation pathways is not yet entirely understood. OBJECTIVE This study aimed to determine the relationship between soluble TREM2 (sTREM2) levels in cerebrospinal fluid (CSF) and plasma samples and other indicators of AD pathology. METHODS Using the Enzyme-Linked Immunosorbent Assay (ELISA), we analyzed 98 samples of AD plasma, 35 samples of plasma from individuals with mild cognitive impairment (MCI), and 11 samples of plasma from healthy controls (HC), as well as 155 samples of AD CSF, 90 samples of MCI CSF, and 50 samples of HC CSF. RESULTS CSF sTREM2 levels were significantly correlated with neurofibrillary degeneration, cognitive decline, and inflammasome activity in AD patients. In contrast to plasma sTREM2, CSF sTREM2 levels in the AD group were higher than those in the MCI and HC groups. Moreover, concentrations of sTREM2 in CSF were substantially higher in the MCI group than in the HC group, indicating that CSF sTREM2 levels could be used not only to distinguish between HC and AD patients but also as a biomarker to detect earlier changes in the MCI stage. CONCLUSIONS The results indicate CSF sTREM2 levels reliably predict neurofibrillary degeneration, cognitive decline, and inflammasome activation, and also have a high diagnostic potential for distinguishing diseased from healthy individuals. To add sTREM2 to the list of required AD biomarkers, future studies will need to include a larger number of patients and utilize a standardized methodology.
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Affiliation(s)
- Ena Španić Popovački
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, 10000 Zagreb, Croatia
| | - Mirjana Babić Leko
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, 10000 Zagreb, Croatia
| | - Lea Langer Horvat
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, 10000 Zagreb, Croatia
| | - Klara Brgić
- Department of Neurosurgery, University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
| | - Željka Vogrinc
- Laboratory for Neurobiochemistry, Department of Laboratory Diagnostics, University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
| | - Marina Boban
- Department of Neurology, University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Nataša Klepac
- Department of Neurology, University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Fran Borovečki
- Department of Neurology, University Hospital Centre Zagreb, Kišpatićeva 12, 10000 Zagreb, Croatia
- School of Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Goran Šimić
- Department of Neuroscience, Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, 10000 Zagreb, Croatia
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Soluble TREM2 in body fluid in Alzheimer's disease and Parkinson's disease. Neurol Sci 2023:10.1007/s10072-023-06729-5. [PMID: 36913148 DOI: 10.1007/s10072-023-06729-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/02/2023] [Indexed: 03/14/2023]
Abstract
BACKGROUND Previous studies showed conflicting results regarding soluble triggering receptor expressed on myeloid cells 2 (sTREM2) level alteration in body fluid in Alzheimer's disease (AD) and Parkinson's disease (PD). METHODS We applied the STATA 12.0 software to compute standard mean difference (SMD) and 95% confidence interval (CI). RESULTS The study showed elevated sTREM2 level in cerebrospinal fluid (CSF) in AD, mild cognitive impairment (MCI), and preclinical AD (pre-AD) patients, compared to healthy controls (HCs) with random effects models (AD: SMD 0.28, 95% CI 0.12 to 0.44, I2 = 77.6%, p < 0.001; MCI: SMD 0.29, 95% CI 0.09 to 0.48, I2 = 89.7%, p < 0.001; pre-AD: SMD 0.24, 95% CI 0.00 to 0.48, I2 = 80.8%, p < 0.001). The study showed no significant difference in sTREM2 level in plasma between AD patients and HCs with a random effects model (SMD 0.06, 95% CI - 0.16 to 0.28, I2 = 65.6%, p = 0.008). The study showed no significant difference in sTREM2 level in CSF or plasma between PD patients and HCs with random effects models (CSF: SMD 0.33, 95% CI - 0.02 to 0.67, I2 = 85.6%, p < 0.001; plasma: SMD 0.37, 95% CI - 0.17 to 0.92, I2 = 77.8%, p = 0.011). CONCLUSIONS In conclusion, the study highlighted the CSF sTREM2 as a promising biomarker in the different clinical stages of AD. More studies were essential to explore the CSF and plasmatic concentrations of sTREM2 alteration in PD.
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Stecker M. A Perspective: Challenges in Dementia Research. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:1368. [PMID: 36295529 PMCID: PMC9609997 DOI: 10.3390/medicina58101368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/21/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022]
Abstract
Although dementia is a common and devastating disease that has been studied intensely for more than 100 years, no effective disease modifying treatment has been found. At this impasse, new approaches are important. The purpose of this paper is to provide, in the context of current research, one clinician's perspective regarding important challenges in the field in the form of specific challenges. These challenges not only illustrate the scope of the problems inherent in finding treatments for dementia, but can also be specific targets to foster discussion, criticism and new research. One common theme is the need to transform research activities from small projects in individual laboratories/clinics to larger multinational projects, in which each clinician and researcher works as an integral part. This transformation will require collaboration between researchers, large corporations, regulatory/governmental authorities and the general population, as well as significant financial investments. However, the costs of transforming the approach are small in comparison with the cost of dementia.
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Affiliation(s)
- Mark Stecker
- Fresno Institute of Neuroscience, Fresno, CA 93720, USA
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