Related Experiment Videos
Induction of metalloelastase mRNA in murine peritoneal macrophages by diethylmaleate
1Department of Biochemistry, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Ibaraki 305, Japan.
Abstract:
Macrophage-specific metalloelastase (MME) hydrolyzes elastin and other matrix proteins and plays an important physiological role in tissue remodeling and pathological tissue destruction. We have examined the effects of diethylmaleate (DEM), an electrophilic agent that reacts with sulfhydryls, on the expression of MME mRNA in mouse peritoneal macrophages. Quantification of MME mRNA by Northern blot analysis revealed that basal mRNA levels were quite low in freshly isolated cells, although mRNA levels increased markedly and reached a steady level within 12 h when cells were cultured in a serum-supplemented RPMI 1640 medium. When macrophages were challenged with DEM at 0.05-1.0 mM for 8 h the expression of the MME gene was enhanced further. In the presence of 0.1 mM DEM, the level of the MME mRNA increased 2-fold compared to the control levels after 6-9 h and decreased to control levels in 24 h. Other electrophilic agents, catechol and 1-chloro-2,4-dinitrobenzene, also enhanced MME gene expression. However, oxidative stress agents such as hydrogen peroxide, menadione, paraquat (an O-2 generator), sodium arsenite and cadmium chloride had no effect on MME gene expression. These results indicate that the electrophilic agents selectively enhance the expression of MME mRNA during primary culture of the macrophages.
Insights
Electrophilic agents like diethylmaleate significantly increase macrophage-specific metalloelastase (MME) mRNA levels in mouse macrophages. This selective gene expression highlights a novel pathway influenced by electrophilic compounds.
Area of Science:
- Biochemistry
- Molecular Biology
- Immunology
Background:
- Macrophage-specific metalloelastase (MME) is crucial for tissue remodeling and destruction.
- MME hydrolyzes elastin and other matrix proteins.
- Understanding MME regulation is vital for studying inflammatory and degenerative diseases.
Purpose of the Study:
- To investigate the effect of electrophilic agents on MME gene expression in mouse peritoneal macrophages.
- To determine if oxidative stress agents impact MME mRNA levels.
Main Methods:
- Primary culture of mouse peritoneal macrophages.
- Northern blot analysis for MME mRNA quantification.
- Treatment with diethylmaleate (DEM) and other electrophilic/oxidative stress agents.
Main Results:
- Basal MME mRNA levels were low but increased upon cell culture.
- DEM (0.05-1.0 mM) significantly enhanced MME mRNA expression in a time-dependent manner.
- Other electrophilic agents also increased MME mRNA, while oxidative stress agents had no effect.
Conclusions:
- Electrophilic agents selectively upregulate MME mRNA expression in macrophages.
- This suggests a specific signaling pathway activated by electrophiles.
- Findings provide insights into MME regulation in macrophage function.