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Updated: May 15, 2025
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Inactivation of microglial LXRβ in early postnatal mice impairs microglia homeostasis and causes long-lasting
Keyi Lv1, Yi Luo1, Tianyao Liu1
1Department of Military Cognitive Psychology, School of Psychology, Third Military Medical University (Army Medical University), Chongqing 400038, China.
Abstract:
Microglia, the largest population of brain immune cells, play an essential role in regulating neuroinflammation by removing foreign materials and debris and in cognition by pruning synapses. Since liver X receptor β (LXRβ) has been identified as a regulator of microglial homeostasis, this study examined whether its removal from microglia affects neuroinflammation and cognitive function. We used a cell-specific tamoxifen-inducible Cre-loxP-mediated recombination to remove LXRβ from microglia specifically. We now report that ablation of LXRβ in microglia in early postnatal life led to a reduction in microglial numbers, distinct morphological changes indicative of microglial activation, and enhanced synapse engulfment accompanied by cognitive deficits. Removal of LXRβ from microglia in adult mice caused no cognitive defects. RNAseq analysis of microglia revealed that loss of LXRβ led to reduced expression of SAll1, a master regulator of microglial homeostasis, while increasing expression of genes associated with microglial activation and CNS disease. This study demonstrates distinctly different functions of microglial LXRβ in developing and adult mice and points to long-term consequences of defective LXRβ signaling in microglia in early life.
Insights
Removing liver X receptor β (LXRβ) from developing microglia impairs brain immune cell function and causes cognitive deficits. Adult removal shows no cognitive impact, highlighting early-life LXRβ importance.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglia are key brain immune cells regulating neuroinflammation and cognition.
- Liver X receptor β (LXRβ) is implicated in microglial homeostasis.
Purpose of the Study:
- To investigate the impact of LXRβ ablation in microglia on neuroinflammation and cognitive function.
- To determine if the timing of LXRβ removal influences its effects.
Main Methods:
- Utilized tamoxifen-inducible Cre-loxP system for cell-specific LXRβ deletion in microglia.
- Assessed microglial numbers, morphology, synapse engulfment, and cognitive performance.
- Performed RNAseq analysis to identify gene expression changes.
Main Results:
- Early postnatal ablation of microglial LXRβ reduced microglial numbers and caused activation.
- LXRβ-deficient microglia exhibited enhanced synapse engulfment and cognitive deficits.
- Adult LXRβ removal did not result in cognitive impairment.
- Loss of LXRβ decreased SAll1 expression and increased genes linked to microglial activation and CNS disease.
Conclusions:
- Microglial LXRβ plays distinct roles in early development versus adulthood.
- Defective LXRβ signaling in early life has lasting consequences on microglial function and cognition.
- LXRβ is crucial for maintaining microglial homeostasis and preventing neuroinflammation.
