Related Experiment Video
Updated: Aug 25, 2026
Bone Marrow-derived Macrophage Production
Published on: November 22, 2013
Identification of macrophage/microglia activation factor (MAF) associated with late endosomes/lysosomes in microglial
Anja U Bräuer1, Robert Nitsch, Nicolai E Savaskan
1Institute of Cell Biology and Neurobiology, Center for Anatomy, Charité University Medical School Berlin, Philippstr. 12, D-10115 Berlin, Germany.
Abstract:
Damage to the central nervous system triggers rapid activation and specific migration of glial cells towards the lesion site. There, glial cells contribute heavily to secondary neuronal changes that take place after lesion. In an attempt to identify the molecular cues of glial activation following brain trauma we performed differential display reverse transcription-polymerase chain reaction screenings from lesioned and control hippocampus. Here we report on the identification of the macrophage/microglia activation factor (MAF), a new membrane protein with seven putative transmembrane domains. Expression analysis revealed that MAF is predominantly expressed in microglial cells in the brain, and is upregulated following brain lesion. Overexpression of MAF in non-glial cells shows an intracellular codistribution with the lysosomal marker endosome/lysosome-associated membrane protein-1 (lamp-1). Furthermore, MAF-transfected cells show that MAF is primarily associated with late endosomes/lysosomes, and that this association can be disrupted by activation of protein kinase C-dependent pathways. In conclusion, these results imply that MAF is involved in the dynamics of lysosomal membranes associated with microglial activation following brain lesion.
Insights
Researchers identified macrophage/microglia activation factor (MAF), a novel protein involved in glial cell activation after brain trauma. MAF is upregulated in microglial cells and associated with lysosomal membranes during brain lesion response.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Central nervous system (CNS) injury triggers glial cell activation and migration to lesion sites.
- Glial cells play a critical role in secondary neuronal damage following CNS trauma.
- Understanding the molecular mechanisms of glial activation is crucial for developing therapeutic strategies.
Purpose of the Study:
- To identify molecular cues responsible for glial activation following brain trauma.
- To characterize a newly discovered membrane protein, macrophage/microglia activation factor (MAF).
Main Methods:
- Differential display reverse transcription-polymerase chain reaction (DD-RT-PCR) screening of lesioned and control hippocampus.
- Expression analysis of MAF in brain tissue.
- Overexpression studies of MAF in non-glial cells to determine its cellular localization and interactions.
Main Results:
- Identification of macrophage/microglia activation factor (MAF), a novel membrane protein with seven transmembrane domains.
- MAF is predominantly expressed in microglial cells and its expression is upregulated after brain lesion.
- MAF is localized to late endosomes/lysosomes, and its association with these organelles is modulated by protein kinase C pathways.
Conclusions:
- MAF is implicated in the dynamic changes of lysosomal membranes during microglial activation post-brain lesion.
- These findings provide insights into the molecular regulation of glial responses to CNS injury.
- MAF represents a potential target for modulating neuroinflammatory processes.
