| 1. |
- Venero, J. L., et al.
(författare)
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ARG1 expression in basal forebrain microglia modulates hippocampal innervation and cognition during postnatal development
- 2023
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Ingår i: Glia. - : John Wiley & Sons. - 0894-1491 .- 1098-1136. ; 71:Suppl. 1, s. E512-E512
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Diversity within microglia, the resident brain immune cells, is reported. Whether microglial subsets constitute different subtypes with intrinsic properties and unique functions has not been fully elucidated. Here, we describe a microglial subtype characterized by the expression of the enzyme Arginase-1, i.e.Arg1+microglia, which is found predominantly in the cholinergic neuron-rich forebrain region during early postnatal development. Arg1+microgliacontain cellular inclusions and exhibit a distinct molecular signature including upregulation of genes such as Apoe, Clec7a, Igf1, Lgals3and Mgl2. Arg1-knockout in microglia results in a deficient cholinergic innervation along with impaired dendritic spine maturation in the hippocampus where cholinergic neurons project, impaired long-term potentiation and cognitive behavioural deficiencies in female mice. Our results expand on microglia diversity and provide insights into distinctive spatiotemporal functions exerted by microglial subtypes.
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| 2. |
- Grabert, K, et al.
(författare)
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Proteome integral solubility alteration high-throughput proteomics assay identifies Collectin-12 as a non-apoptotic microglial caspase-3 substrate
- 2023
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Ingår i: Cell death & disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 14:3, s. 192-
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Tidskriftsartikel (refereegranskat)abstract
- Caspases are a family of proteins mostly known for their role in the activation of the apoptotic pathway leading to cell death. In the last decade, caspases have been found to fulfill other tasks regulating the cell phenotype independently to cell death. Microglia are the immune cells of the brain responsible for the maintenance of physiological brain functions but can also be involved in disease progression when overactivated. We have previously described non-apoptotic roles of caspase-3 (CASP3) in the regulation of the inflammatory phenotype of microglial cells or pro-tumoral activation in the context of brain tumors. CASP3 can regulate protein functions by cleavage of their target and therefore could have multiple substrates. So far, identification of CASP3 substrates has been performed mostly in apoptotic conditions where CASP3 activity is highly upregulated and these approaches do not have the capacity to uncover CASP3 substrates at the physiological level. In our study, we aim at discovering novel substrates of CASP3 involved in the normal regulation of the cell. We used an unconventional approach by chemically reducing the basal level CASP3-like activity (by DEVD-fmk treatment) coupled to a Mass Spectrometry screen (PISA) to identify proteins with different soluble amounts, and consequently, non-cleaved proteins in microglia cells. PISA assay identified several proteins with significant change in their solubility after DEVD-fmk treatment, including a few already known CASP3 substrates which validated our approach. Among them, we focused on the Collectin-12 (COLEC12 or CL-P1) transmembrane receptor and uncovered a potential role for CASP3 cleavage of COLEC12 in the regulation of the phagocytic capacity of microglial cells. Taken together, these findings suggest a new way to uncover non-apoptotic substrates of CASP3 important for the modulation of microglia cell physiology.
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| 3. |
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| 4. |
- Stratoulias, Vassilis, et al.
(författare)
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ARG1-expressing microglia show a distinct molecular signature and modulate postnatal development and function of the mouse brain
- 2023
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Ingår i: Nature Neuroscience. - : Nature Publishing Group. - 1097-6256 .- 1546-1726. ; 26:6, s. 1008-1020
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Tidskriftsartikel (refereegranskat)abstract
- Molecular diversity of microglia, the resident immune cells in the CNS, is reported. Whether microglial subsets characterized by the expression of specific proteins constitute subtypes with distinct functions has not been fully elucidated. Here we describe a microglial subtype expressing the enzyme arginase-1 (ARG1; that is, ARG1+ microglia) that is found predominantly in the basal forebrain and ventral striatum during early postnatal mouse development. ARG1+ microglia are enriched in phagocytic inclusions and exhibit a distinct molecular signature, including upregulation of genes such as Apoe, Clec7a, Igf1, Lgals3 and Mgl2, compared to ARG1- microglia. Microglial-specific knockdown of Arg1 results in deficient cholinergic innervation and impaired dendritic spine maturation in the hippocampus where cholinergic neurons project, which in turn results in impaired long-term potentiation and cognitive behavioral deficiencies in female mice. Our results expand on microglia diversity and provide insights into microglia subtype-specific functions.
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