Carbon monoxide controls microglial erythrophagocytosis by regulating CD36 surface expression to reduce the severity of hemorrhagic injury

Abstract: Microglial erythrophagocytosis is crucial in injury response to hemorrhagic stroke. We hypothesized that regulation of microglial erythrophagocytosis via HO‐1/CO depends on a pathway involving reactive oxygen species (ROS) and CD36 surface‐expression. The microglial BV‐2 cell line and primary microglia (PMG) were incubated +/−blood and +/−CO‐exposure. PMG isolated from tissue‐specific HO‐1‐deficient (LyzM‐Cre‐Hmox1 fl/fl) and CD36 −/− mice or siRNA against AMPK (AMP‐activated protein kinase) were used to test our hypothesis. In a murine subarachnoid hemorrhage (SAH) model, we compared neuronal injury in wild‐type and CD36 −/− mice. Readouts included vasospasm, microglia activation, neuronal apoptosis, and spatial memory. We observed increased microglial HO‐1‐expression after blood‐exposure. A burst in ROS‐production was seen after CO‐exposure, which led to increased amounts of phosphorylated AMPK with subsequently enhanced CD36 surface‐expression. Naïve PMG from LyzM‐Cre‐Hmox1 fl/fl mice showed reduced ROS‐production and CD36 surface‐expression and failed to respond to CO with increased CD36 surface‐expression. Lack of HO‐1 and CD36 resulted in reduced erythrophagocytosis that could not be rescued with CO. Erythrophagocytosis was enhanced in BV‐2 cells in the presence of exogenous CO, which was abolished in cells treated with siRNA to AMPK. CD36 −/− mice subjected to SAH showed enhanced neuronal cell death, which resulted in impaired spatial memory function. We demonstrate that microglial phagocytic function partly depends on a pathway involving HO‐1 with changes in ROS‐production, phosphorylated AMPK, and surface expression of CD36. CD36 was identified as a crucial component in blood clearance after hemorrhage that ultimately determines neuronal outcome. These results demand further investigations studying the potential neuroprotective properties of CO

Location
Deutsche Nationalbibliothek Frankfurt am Main
Extent
Online-Ressource
Language
Englisch
Notes
Glia. - 68, 11 (2020) , 2427-2445, ISSN: 1098-1136

Keyword
Hirnblutung
Kohlenmonoxid
Mikroglia
Phagozytose

Event
Veröffentlichung
(where)
Freiburg
(who)
Universität
(when)
2020
Creator

DOI
10.1002/glia.23864
URN
urn:nbn:de:bsz:25-freidok-1673370
Rights
Der Zugriff auf das Objekt ist unbeschränkt möglich.
Last update
25.03.2025, 1:52 PM CET

Data provider

This object is provided by:
Deutsche Nationalbibliothek. If you have any questions about the object, please contact the data provider.

Associated

Time of origin

  • 2020

Other Objects (12)