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Updated: Aug 9, 2026
Primary Microglia Isolation from Mixed Glial Cell Cultures of Neonatal Rat Brain Tissue
Published on: August 15, 2012
Mitogen-activated protein kinases activated by lipopolysaccharide and beta-amyloid in cultured rat microglia
Abstract:
To test whether mitogen-activated protein kinases (MAPKs) are involved in microglial activation, pure microglia prepared from 1- to 3-day-old rat brains were activated with either 100 ng/ml lipopolysaccharide (LPS) or 5 nM synthetic beta-amyloid (Abeta) (25-35). The patterns of MAPK activation following LPS and Abeta treatment were very similar. Three MAPK subtypes, p38, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) were activated within 15 min and the activities of p38 and ERK were rapidly reduced to background level within 30 min while that of JNK was maintained for over 1 h. Both inhibitors of p38 (SB203580) and ERK pathway (PD098059) reduced LPS-induced nitric oxide (NO) release and Abeta-induced tumor necrosis factor-alpha (TNF-alpha) release. Furthermore, co-treatment of SB203580 and PD098059 additively reduced NO and TNF-alpha release. These results suggest that MAPK, at least p38 and ERK, mediate LPS-, and Abeta-induced microglial activation.
Insights
Mitogen-activated protein kinases (MAPKs) mediate microglial activation by lipopolysaccharide (LPS) and beta-amyloid (Abeta). Inhibiting p38 and extracellular signal-regulated kinase (ERK) pathways reduced inflammatory responses, suggesting their crucial role.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglia play a critical role in neuroinflammation.
- Mitogen-activated protein kinases (MAPKs) are signaling pathways implicated in cellular responses.
Purpose of the Study:
- To investigate the involvement of MAPKs in microglial activation induced by lipopolysaccharide (LPS) and beta-amyloid (Abeta).
Main Methods:
- Primary microglia cultures from rat brains were stimulated with LPS or synthetic Abeta (25-35).
- MAPK activation (p38, ERK, JNK/SAPK) was assessed.
- The effects of specific MAPK inhibitors (SB203580 for p38, PD098059 for ERK) on nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) release were evaluated.
Main Results:
- LPS and Abeta induced similar MAPK activation patterns, involving p38, ERK, and JNK/SAPK.
- p38 and ERK activation peaked early, while JNK/SAPK activation was sustained.
- Inhibitors of p38 and ERK pathways significantly reduced LPS-induced NO and Abeta-induced TNF-alpha release.
- Combined inhibition additively decreased inflammatory mediator release.
Conclusions:
- MAPK signaling pathways, particularly p38 and ERK, are essential mediators of LPS- and Abeta-induced microglial activation.
- Targeting these MAPK pathways may offer therapeutic strategies for neuroinflammatory conditions.
