Ganglioside GD3 is up-regulated in microglia and regulates phagocytosis following global cerebral ischemia.

Autor: Wang J; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA., Zhang Q; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA., Lu Y; Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, USA., Dong Y; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA., Dhandapani KM; Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, USA., Brann DW; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA., Yu RK; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA.
Jazyk: angličtina
Zdroj: Journal of neurochemistry [J Neurochem] 2021 Aug; Vol. 158 (3), pp. 737-752. Date of Electronic Publication: 2021 Jul 07.
DOI: 10.1111/jnc.15455
Abstrakt: Gangliosides, the major sialic-acid containing glycosphingolipids in the mammalian brain, play important roles in brain development and neural functions. Here, we show that the b-series ganglioside GD3 and its biosynthetic enzyme, GD3-synthase (GD3S), were up-regulated predominantly in the microglia of mouse hippocampus from 2 to 7 days following global cerebral ischemia (GCI). Interestingly, GD3S knockout (GD3S-KO) mice exhibited decreased hippocampal neuronal loss following GCI, as compared to wild-type (WT) mice. While comparable levels of astrogliosis and microglial proliferation were observed between WT and GD3S-KO mice, the phagocytic capacity of the GD3S-KO microglia was significantly compromised after GCI. At 2 and 4 days following GCI, the GD3S-KO microglia demonstrated decreased amoebic morphology, reduced neuronal material engulfment, and lower expression of the phagolysosome marker CD68, as compared to the WT microglia. Finally, by using a microglia-primary neuron co-culture model, we demonstrated that the GD3S-KO microglia isolated from mouse brains at 2 days after GCI are less neurotoxic to co-cultured hippocampal neurons than the WT-GCI microglia. Moreover, the percentage of microglia with engulfed neuronal elements in the co-cultured wells was also significantly decreased in the GD3S-KO mice after GCI. Interestingly, the impaired phagocytic capacity of GD3S-KO microglia could be partially restored by pre-treatment with exogenous ganglioside GD3. Altogether, this study provides functional evidence that ganglioside GD3 regulates phagocytosis by microglia in an ischemic stroke model. Our data also suggest that the GD3-linked microglial phagocytosis may contribute to the mechanism of delayed neuronal death following ischemic brain injury.
(© 2021 International Society for Neurochemistry.)
Databáze: MEDLINE
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