Inflammatory neuronal loss in the substantia nigra induced by systemic lipopolysaccharide is prevented by knockout of the P2Y 6 receptor in mice

Inflammation may contribute to multiple brain pathologies. One cause of inflammation is lipopolysaccharide/endotoxin (LPS), the levels of which are elevated in blood and/or brain during bacterial infections, gut dysfunction and neurodegenerative diseases, such as Parkinson's disease. How inflam...

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Bibliographic Details
Authors: Milde, Stefan, van Tartwijk, Francesca W., Vilalta, Anna, Hornik, Tamara C., Dundee, Jacob M., Puigdellívol Cañadell, Maria del Mar, Brown, Guy C.
Format: article
Status:Published version
Publication Date:2021
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/186581
Online Access:https://hdl.handle.net/2445/186581
Access Level:Open access
Keyword:Mort cel·lular
Micròglia
Malaltia de Parkinson
Tronc de l'encèfal
Malalties cerebrals
Endotoxines
Cell death
Microglia
Parkinson's disease
Brain stem
Brain diseases
Endotoxins
Description
Summary:Inflammation may contribute to multiple brain pathologies. One cause of inflammation is lipopolysaccharide/endotoxin (LPS), the levels of which are elevated in blood and/or brain during bacterial infections, gut dysfunction and neurodegenerative diseases, such as Parkinson's disease. How inflammation causes neuronal loss is unclear, but one potential mechanism is microglial phagocytosis of neurons, which is dependent on the microglial P2Y6 receptor. We investigated here whether the P2Y6 receptor was required for inflammatory neuronal loss. Intraperitoneal injection of LPS on 4 successive days resulted in specific loss of dopaminergic neurons (measured as cells staining with tyrosine hydroxylase or NeuN) in the substantia nigra of wild-type mice, but no neuronal loss in cortex or hippocampus. This supports the hypothesis that neuronal loss in Parkinson's disease may be driven by peripheral LPS. By contrast, there was no LPS-induced neuronal loss in P2Y6 receptor knockout mice. In vitro, LPS-induced microglial phagocytosis of cells was prevented by inhibition of the P2Y6 receptor, and LPS-induced neuronal loss was reduced in mixed glial-neuronal cultures from P2Y6 receptor knockout mice. This supports the hypothesis that microglial phagocytosis contributes to inflammatory neuronal loss, and can be prevented by blocking the P2Y6 receptor, suggesting that P2Y6 receptor antagonists might be used to prevent inflammatory neuronal loss in Parkinson's disease and other brain pathologies involving inflammatory neuronal loss.