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Steiner K, Yilmaz SN, Gern A, Marksteiner J, Faserl K, Villunger M, Sarg B, Humpel C. From Organotypic Mouse Brain Slices to Human Alzheimer Plasma Biomarkers: A Focus on Microglia. Biomolecules 2024; 14:1109. [PMID: 39334874 PMCID: PMC11430359 DOI: 10.3390/biom14091109] [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: 08/08/2024] [Revised: 08/22/2024] [Accepted: 08/28/2024] [Indexed: 09/30/2024] Open
Abstract
Alzheimer's disease is a severe neurodegenerative disorder, and the discovery of biomarkers is crucial for early diagnosis. While the analysis of biomarkers in cerebrospinal fluid is well accepted, there are currently no blood biomarkers available. Our research focuses on identifying novel plasma biomarkers for Alzheimer's disease. To achieve this, we employed a technique that involves coupling human plasma to mouse organotypic brain slices via microcontact prints. After culturing for two weeks, we assessed Iba1-immunopositive microglia on these microcontact prints. We hypothesized that plasma from Alzheimer's patients contains factors that affect microglial migration. Our data indicated that plasma from Alzheimer's patients significantly inhibited the migration of round Iba1-immunoreactive microglia (13 ± 3, n = 24, p = 0.01) compared to healthy controls (50 ± 16, n = 23). Based on these findings, we selected the most promising plasma samples and conducted mass spectrometry using a differential approach, and we identified four potential biomarkers: mannose-binding protein C, macrophage receptor MARCO, complement factor H-related protein-3, and C-reactive protein. Our method represents a novel and innovative approach to translate research findings from mouse models to human applications.
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Affiliation(s)
- Katharina Steiner
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.S.); (S.N.Y.); (A.G.)
| | - Sakir Necat Yilmaz
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.S.); (S.N.Y.); (A.G.)
- Department of Histology and Embryology, Faculty of Medicine, Mersin University, Mersin 33110, Turkey
| | - Alessa Gern
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.S.); (S.N.Y.); (A.G.)
| | - Josef Marksteiner
- Department of Psychiatry and Psychotherapy A, Hall State Hospital, 6060 Hall in Tirol, Austria;
| | - Klaus Faserl
- Protein Core Facility, Institute of Medical Biochemistry, CCB-Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.F.); (M.V.); (B.S.)
| | - Mathias Villunger
- Protein Core Facility, Institute of Medical Biochemistry, CCB-Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.F.); (M.V.); (B.S.)
| | - Bettina Sarg
- Protein Core Facility, Institute of Medical Biochemistry, CCB-Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.F.); (M.V.); (B.S.)
| | - Christian Humpel
- Laboratory of Psychiatry and Experimental Alzheimer’s Research, Medical University of Innsbruck, 6020 Innsbruck, Austria; (K.S.); (S.N.Y.); (A.G.)
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Sudwarts A, Thinakaran G. Alzheimer's genes in microglia: a risk worth investigating. Mol Neurodegener 2023; 18:90. [PMID: 37986179 PMCID: PMC10662636 DOI: 10.1186/s13024-023-00679-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
Despite expressing many key risk genes, the role of microglia in late-onset Alzheimer's disease pathophysiology is somewhat ambiguous, with various phenotypes reported to be either harmful or protective. Herein, we review some key findings from clinical and animal model investigations, discussing the role of microglial genetics in mediating perturbations from homeostasis. We note that impairment to protective phenotypes may include prolonged or insufficient microglial activation, resulting in dysregulated metabolomic (notably lipid-related) processes, compounded by age-related inflexibility in dynamic responses. Insufficiencies of mouse genetics and aggressive transgenic modelling imply severe limitations in applying current methodologies for aetiological investigations. Despite the shortcomings, widely used amyloidosis and tauopathy models of the disease have proven invaluable in dissecting microglial functional responses to AD pathophysiology. Some recent advances have brought modelling tools closer to human genetics, increasing the validity of both aetiological and translational endeavours.
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Affiliation(s)
- Ari Sudwarts
- Byrd Alzheimer's Center and Research Institute, University of South Florida, Tampa, FL, 33613, USA.
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
| | - Gopal Thinakaran
- Byrd Alzheimer's Center and Research Institute, University of South Florida, Tampa, FL, 33613, USA.
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
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Cai W, Wu T, Chen N. The Amyloid-Beta Clearance: From Molecular Targets to Glial and Neural Cells. Biomolecules 2023; 13:313. [PMID: 36830682 PMCID: PMC9953441 DOI: 10.3390/biom13020313] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023] Open
Abstract
The deposition of amyloid-beta (Aβ) plaques in the brain is one of the primary pathological characteristics of Alzheimer's disease (AD). It can take place 20-30 years before the onset of clinical symptoms. The imbalance between the production and the clearance of Aβ is one of the major causes of AD. Enhancing Aβ clearance at an early stage is an attractive preventive and therapeutic strategy of AD. Direct inhibition of Aβ production and aggregation using small molecules, peptides, and monoclonal antibody drugs has not yielded satisfactory efficacy in clinical trials for decades. Novel approaches are required to understand and combat Aβ deposition. Neurological dysfunction is a complex process that integrates the functions of different types of cells in the brain. The role of non-neurons in AD has not been fully elucidated. An in-depth understanding of the interactions between neurons and non-neurons can contribute to the elucidation of Aβ formation and the identification of effective drug targets. AD patient-derived pluripotent stem cells (PSCs) contain complete disease background information and have the potential to differentiate into various types of neurons and non-neurons in vitro, which may bring new insight into the treatment of AD. Here, we systematically review the latest studies on Aβ clearance and clarify the roles of cell interactions among microglia, astroglia and neurons in response to Aβ plaques, which will be beneficial to explore methods for reconstructing AD disease models using inducible PSCs (iPSCs) through cell differentiation techniques and validating the applications of models in understanding the formation of Aβ plaques. This review may provide the most promising directions of finding the clues for preventing and delaying the development of AD.
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Affiliation(s)
| | | | - Ning Chen
- Tianjiu Research and Development Center for Exercise Nutrition and Foods, Hubei Key Laboratory of Exercise Training and Monitoring, College of Sports Medicine, Wuhan Sports University, Wuhan 430079, China
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Warden AS, Han C, Hansen E, Trescott S, Nguyen C, Kim R, Schafer D, Johnson A, Wright M, Ramirez G, Lopez-Sanchez M, Coufal NG. Tools for studying human microglia: In vitro and in vivo strategies. Brain Behav Immun 2023; 107:369-382. [PMID: 36336207 PMCID: PMC9810377 DOI: 10.1016/j.bbi.2022.10.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/11/2022] [Accepted: 10/13/2022] [Indexed: 11/06/2022] Open
Abstract
Microglia may only represent 10% of central nervous system (CNS) cells but they perform critical roles in development, homeostasis and neurological disease. Microglia are also environmentally regulated, quickly losing their transcriptomic and epigenetic signature after leaving the CNS. This facet of microglia biology is both fascinating and technically challenging influencing the study of the genetics and function of human microglia in a manner that recapitulates the CNS environment. In this review we provide a comprehensive overview of existing in vitro and in vivo methodology to study human microglia, such as immortalized cells lines, stem cell-derived microglia, cerebral organoids and xenotransplantation. Since there is currently no single method that completely recapitulates all hallmarks of human ex vivo adult homeostatic microglia, we also discuss the advantages and limitations of each existing model as a practical guide for researchers.
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Affiliation(s)
- Anna S Warden
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Claudia Han
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emily Hansen
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Samantha Trescott
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Celina Nguyen
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Roy Kim
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Danielle Schafer
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA
| | - Avalon Johnson
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Madison Wright
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gabriela Ramirez
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark Lopez-Sanchez
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nicole G Coufal
- Sanford Consortium for Regenerative Medicine, La Jolla, CA 92037, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA.
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