Related Experiment Videos
Interferon-gamma regulation of C3 gene expression in human astroglioma cells
S R Barnum1, J L Jones, E N Benveniste
1Department of Microbiology, University of Alabama, Birmingham 35294.
Abstract:
In this report, we show that the human astroglioma cell line, D54-MG, constitutively expresses C3 mRNA and secretes antigenically detectable C3 protein. The cytokine interferon-gamma (IFN-gamma) enhances C3 mRNA and protein expression by D54-MG cells in a dose- and time-dependent manner. C3 mRNA from both D54-MG cells and primary human adult astrocytes has the same apparent size (5.1-5.2 kb) as C3 mRNA from hepatocyte and monocyte cell lines. Constitutive C3 mRNA levels in D54-MG cells and primary human astrocytes are comparable. Primary rat astrocytes also constitutively express C3 mRNA, which is enhanced upon exposure to IFN-gamma. These data are novel since expression of C3 in other cell types is refractory to IFN-gamma. In the central nervous system (CNS), endogenous complement production by astrocytes, and enhancement by the cytokine IFN-gamma, may contribute to the pathogenesis of inflammatory demyelinating diseases such as multiple sclerosis (MS).
Insights
Astrocytes, a type of brain cell, produce complement C3, a protein involved in inflammation. This production is increased by interferon-gamma (IFN-gamma), potentially contributing to diseases like multiple sclerosis (MS).
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- The complement system plays a role in CNS inflammation.
- Astrocytes are glial cells in the central nervous system (CNS).
- Interferon-gamma (IFN-gamma) is a cytokine involved in immune responses.
Purpose of the Study:
- To investigate the expression of complement C3 in astrocytes.
- To determine the effect of IFN-gamma on C3 expression in astrocytes.
- To explore the potential role of astrocyte-derived C3 in CNS inflammatory diseases.
Main Methods:
- Analysis of C3 mRNA and protein expression in D54-MG astroglioma cells and primary human and rat astrocytes.
- Treatment with varying doses and durations of IFN-gamma.
- Comparison of C3 mRNA size across different cell types.
Main Results:
- D54-MG cells and primary human astrocytes constitutively express C3 mRNA and protein.
- IFN-gamma dose- and time-dependently enhances C3 expression in D54-MG cells.
- Primary rat astrocytes also express C3 mRNA, which is upregulated by IFN-gamma.
- C3 mRNA size in astrocytes is similar to that in hepatocytes and monocytes.
- This IFN-gamma-mediated upregulation of C3 in astrocytes is a novel finding.
Conclusions:
- Astrocytes produce complement C3, and this production is enhanced by IFN-gamma.
- Endogenous complement production by astrocytes, modulated by IFN-gamma, may contribute to the pathogenesis of inflammatory demyelinating diseases like multiple sclerosis (MS).