Related Experiment Videos
Water-soluble antioxidants inhibit macrophage recognition of oxidized erythrocytes
M Beppu1, T Watanabe, A Yokota
1School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
Abstract:
Effect of exogenously added water-soluble antioxidants on the mouse macrophage lectin-like receptor activity for oxidized erythrocytes was investigated. A monolayer of thioglycollate-induced mouse peritoneal macrophages was preincubated with each of the antioxidants at 37 degrees C for 1 h, and the binding for mouse erythrocytes oxidized with ADP-chelated Fe(III) was examined. The binding was decreased by preincubation of macrophages with ascorbic acid-related compounds including ascorbic acid, erythorbic acid and dehydroascorbic acid in a dose-dependent fashion at relatively high concentrations above 10 microM. The binding was similarly decreased by preincubation of macrophages with catechin compounds including epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate in a dose-dependent fashion at 0.01-100 microM. The binding was more effectively decreased by preincubation of macrophages with thiol-related compounds including glutathione, oxidized glutathione, glutathione isopropyl ester and N-acetylcysteine in a dose dependent fashion at relatively low doses below 1 microM. These results showed that water-soluble antioxidants especially glutathione and its derivatives reduced the ability of macrophages to bind oxidized erythrocytes, suggesting that the activity of lectin-like receptors of macrophages for oxidized erythrocytes was regulated by oxidative mechanisms.
Insights
Water-soluble antioxidants, particularly glutathione, reduce macrophage binding of oxidized erythrocytes. This suggests macrophage lectin-like receptor activity is regulated by oxidative mechanisms, impacting immune cell function.
Area of Science:
- Immunology
- Biochemistry
- Cell Biology
Background:
- Macrophages play a crucial role in immune responses, including the clearance of oxidized erythrocytes.
- Lectin-like receptors on macrophages are involved in recognizing and binding to oxidized cells.
- Oxidative stress can influence cellular functions, including receptor activity.
Purpose of the Study:
- To investigate the effect of water-soluble antioxidants on the lectin-like receptor activity of mouse macrophages for oxidized erythrocytes.
- To determine which types of antioxidants and at what concentrations modulate this binding activity.
Main Methods:
- Thioglycollate-induced mouse peritoneal macrophages were cultured as a monolayer.
- Macrophages were preincubated with various water-soluble antioxidants (ascorbic acid derivatives, catechin derivatives, thiol compounds) at 37°C for 1 hour.
- The binding of oxidized mouse erythrocytes (oxidized with ADP-chelated Fe(III)) to the preincubated macrophages was quantified.
Main Results:
- Ascorbic acid and catechin compounds decreased erythrocyte binding in a dose-dependent manner at concentrations above 10 microM and 0.01-100 microM, respectively.
- Thiol compounds, including glutathione and its derivatives, significantly reduced erythrocyte binding at lower doses (below 1 microM).
- Glutathione and its derivatives demonstrated the most effective reduction in binding.
Conclusions:
- Water-soluble antioxidants, especially thiol compounds like glutathione, can modulate macrophage lectin-like receptor activity.
- The binding of oxidized erythrocytes to macrophages is regulated by oxidative mechanisms.
- These findings highlight a potential role for antioxidants in regulating macrophage-mediated clearance of oxidized cells.