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Updated: Jul 16, 2026
Isolation of Murine Peritoneal Macrophages to Carry Out Gene Expression Analysis Upon Toll-like Receptors Stimulation
Published on: April 29, 2015
LPS suppresses expression of asialoglycoprotein-binding protein through TLR4 in thioglycolate-elicited peritoneal
Bruce Yong Ma1, Mio Kaihama, Motohiro Nonaka
1Research Center for Glycobiotechnology, Ritsumeikan University, Shiga, 525-8577, Japan. byma@fc.ritsumei.ac.jp
Abstract:
Macrophages are known to express various types of endocytosis receptors that mediate the removal of foreign pathogens. Macrophage asialoglycoprotein-binding protein (M-ASGP-BP) is a Gal/GalNAc-specific lectin, which functions as an endocytosis receptor. We found here that LPS is able to down-regulate the mRNA expression of M-ASGP-BP in a time-dependent manner using thioglycolate-elicited rat and mouse peritoneal macrophages. However, LPS does not modulate the mRNA expression of M-ASGP-BP from macrophages of C3H/HeN mice, which have a point mutation of TLR4, the primary LPS receptor. Furthermore, an inhibitor of NF-kappaB was observed to efficiently block the suppressive effect of LPS on M-ASGP-BP as well as to inhibit the phosphorylated IkappaB. These results demonstrate that the mRNA expression of M-ASGP-BP is down-regulated by the LPS-mediated TLR4 pathway involving NF-kappaB activation, suggesting that engagement of M-ASGP-BP by LPS may yield a negative signal that interferes with the LPS-induced positive signals mediated by proinflammatory cytokines.
Insights
Lipopolysaccharide (LPS) down-regulates macrophage asialoglycoprotein-binding protein (M-ASGP-BP) mRNA expression via the Toll-like receptor 4 (TLR4) pathway. This LPS-mediated suppression involves Nuclear Factor-kappaB (NF-kappaB) activation.
Area of Science:
- Immunology
- Cell Biology
- Molecular Biology
Background:
- Macrophages utilize endocytosis receptors to clear pathogens.
- Macrophage asialoglycoprotein-binding protein (M-ASGP-BP) is a Gal/GalNAc-specific lectin acting as an endocytosis receptor.
Purpose of the Study:
- To investigate the effect of lipopolysaccharide (LPS) on M-ASGP-BP mRNA expression in macrophages.
- To elucidate the molecular pathway involved in LPS-mediated regulation of M-ASGP-BP.
Main Methods:
- Quantitative analysis of M-ASGP-BP mRNA expression in rat and mouse peritoneal macrophages.
- Utilizing macrophages from C3H/HeN mice with a mutated Toll-like receptor 4 (TLR4).
- Employing a Nuclear Factor-kappaB (NF-kappaB) inhibitor to assess its effect on LPS-induced M-ASGP-BP modulation.
Main Results:
- LPS significantly down-regulated M-ASGP-BP mRNA expression in a time-dependent manner.
- This suppressive effect was absent in macrophages from TLR4-mutated mice, indicating TLR4 dependence.
- NF-kappaB inhibition blocked LPS-induced M-ASGP-BP suppression and IkappaB phosphorylation.
Conclusions:
- LPS down-regulates M-ASGP-BP mRNA expression through the TLR4 pathway.
- NF-kappaB activation is essential for the LPS-mediated suppression of M-ASGP-BP.
- LPS binding to M-ASGP-BP may generate a negative signal that counteracts LPS-induced pro-inflammatory responses.
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