The microglial translocator protein (TSPO) in Alzheimer's disease reflects a phagocytic phenotype.

Autor: Garland EF; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK., Antony H; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK., Kulagowska L; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK., Scott T; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK., Rogien C; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK., Bottlaender M; Paris-Saclay University, CEA, CNRS, Service Hospitalier Frederic Joliot, Orsay, Inserm, BioMaps, France.; UNIACT Neurospin, CEA, Gif-Sur-Yvette, France., Nicoll JAR; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.; Department of Cellular Pathology, University Hospital Southampton NHS Trust, Southampton, UK., Boche D; Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK. d.boche@soton.ac.uk.
Jazyk: angličtina
Zdroj: Acta neuropathologica [Acta Neuropathol] 2024 Nov 14; Vol. 148 (1), pp. 62. Date of Electronic Publication: 2024 Nov 14.
DOI: 10.1007/s00401-024-02822-x
Abstrakt: Translocator protein (TSPO) is a mitochondrial protein expressed by microglia, ligands for which are used as a marker of neuroinflammation in PET studies of Alzheimer's disease (AD). We previously showed increasing TSPO load in the cerebral cortex with AD progression, consistent with TSPO PET scan findings. Here, we aim to characterise the microglial phenotype associated with TSPO expression to aid interpretation of the signal generated by TSPO ligands in patients. Human post-mortem sections of temporal lobe (TL) and cerebellum (Cb) from cases classified by Braak group (0-II, III-IV, V-VI; each n = 10) were fluorescently double labelled for TSPO and microglial markers: Iba1, HLA-DR, CD68, MSR-A and CD64. Quantification was performed on scanned images using QuPath software to assess the microglial phenotype of TSPO. Qualitative analysis was also performed for TSPO with GFAP (astrocytes), CD31 (endothelial cells) and CD163 (perivascular macrophages) to characterise the cellular profile of TSPO. The percentage of CD68 + TSPO + double-labelled cells was significantly higher than for other microglial markers in both brain regions and in all Braak stages, followed by MSR-A + TSPO + microglia. Iba1 + TSPO + cells were more numerous in the cerebellum than the temporal lobe, while CD64 + TSPO + cells were more numerous in the temporal lobe. No differences were observed for the other microglial markers. TSPO expression was also detected in endothelial cells, but not detected in astrocytes nor in perivascular macrophages. Our data suggest that TSPO is mainly related to a phagocytic profile of microglia (CD68 + ) in human AD, potentially highlighting the ongoing neurodegeneration.
Competing Interests: Declarations Conflict of interests The authors report no competing interests. Ethical approval The study was carried out in accordance with relevant guidelines and regulations under the South–West Dementia Brain Bank ethical approval (NRES Committee South–West Central Bristol, REC reference: 08/H0106/28 + 5).
(© 2024. The Author(s).)
Databáze: MEDLINE
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