Related Experiment Video
Updated: Aug 15, 2026
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Lipopolysaccharide-activated SHP-1-deficient motheaten microglia release increased nitric oxide, TNF-alpha, and
Jie Zhao1, Diane M Brooks, Diana I Lurie
1Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy and Allied Health Sciences, University of Montana, Missoula, MT 59812, USA.
Abstract:
Accumulating evidence suggests a deleterious role for activated microglia in facilitating neuronal death by producing neurocytotoxic substances during injury, infection, or neurodegenerative diseases. After cochlear ablation, abnormal microglial activation accompanied by increased neuronal loss within the auditory brainstem occurs in motheaten (me/me) mice deficient in the protein tyrosine phosphatase SHP-1. To determine whether abnormally activated microglia contribute to neuronal death in me/me mice, primary microglial cultures from me/me and wild-type mouse cortices were stimulated by the bacterial endotoxin lipopolysaccharide (LPS) to evaluate the secretion of the neurotoxic mediators nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta). Me/me microglia release significantly greater amounts of all three mediators compared with wild-type microglia. However, the increased release of these compounds in microglia lacking SHP-1 does not appear to occur through activation of extracellular signal-regulated kinase (ERK), p38 kinase subgroups of mitogen-activated protein (MAP) kinases, or increases in NF-kappaB-inducing kinase (NIK). These results suggest that abnormal microglial activation and release of neurotoxic compounds may potentiate neuronal death in deafferented cells and can thus potentiate neurodegeneration in the me/me brainstem. Our data also indicate that SHP-1 is engaged in signaling pathways in LPS-activated microglia, but not through regulation of the ERK and p38 MAP kinases.
Insights
Motheaten mice with deficient SHP-1 show abnormal microglial activation and release more neurotoxic substances, contributing to neuronal death in the brainstem. This suggests SHP-1 regulates microglial responses in neuroinflammation.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Activated microglia can cause neuronal death by releasing neurotoxic substances.
- Motheaten (me/me) mice, lacking protein tyrosine phosphatase SHP-1, exhibit abnormal microglial activation and neuronal loss in the auditory brainstem after cochlear ablation.
Purpose of the Study:
- To investigate if abnormally activated microglia contribute to neuronal death in me/me mice.
- To evaluate the role of SHP-1 in microglial activation and neurotoxic mediator release.
Main Methods:
- Primary microglial cultures from me/me and wild-type mice were stimulated with lipopolysaccharide (LPS).
- Secretion of nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta) was measured.
- Signaling pathways including ERK, p38 MAP kinases, and NIK were assessed.
Main Results:
- Me/me microglia released significantly higher amounts of NO, TNF-alpha, and IL-1beta compared to wild-type microglia.
- The increased mediator release in me/me microglia did not involve activation of ERK, p38 MAP kinases, or NIK.
- SHP-1 is involved in signaling pathways in LPS-activated microglia, but not via ERK or p38 MAP kinases.
Conclusions:
- Abnormal microglial activation and enhanced neurotoxic compound release in SHP-1 deficient microglia may worsen neuronal death in deafferented cells.
- These findings suggest a role for SHP-1 in regulating microglial inflammatory responses and neuroprotection.
