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Investigation of Macrophage Polarization Using Bone Marrow Derived Macrophages
Published on: June 23, 2013
Rab26 alleviates sepsis-induced immunosuppression as a master regulator of macrophage ferroptosis and polarization
Daohui Gong1, Xueping Liu1, Pengfei Wu1
1Institute of Respiratory Diseases, Department of Pulmonary and Critical Care Medicine, Xinqiao Hospital, Third Military Medical University (Army Medical University), Chongqing, 400037, China.
Abstract:
Macrophage dysfunction is a significant contributor to more than 70 % of sepsis-related deaths, specifically secondary bacterial infections, during the immunosuppression stage of sepsis. Nevertheless, the role of Rab26 in this context remains unclear. In this study, we observed a substantial decrease in Rab26 expression in macrophages during the immunosuppressive phase of sepsis, which was also found to be suppressed by high extracellular levels of HMGB1. During the progression of sepsis, Rab26 deficiency promotes a polarization shift from the M1 to the M2-like phenotype in macrophages, rendering them susceptible to ferroptosis. Subsequent experimentation has revealed that Rab26 deficiency facilitates the degradation of GPX4, thereby aggravating macrophage ferroptosis through the upregulation of levels of lipid ROS, MDA, and ferrous iron induced by RSL3, a ferroptosis inducer. Additionally, Rab26-deficient mice in the immunosuppressed phase of sepsis exhibit heightened susceptibility to secondary infections, leading to exacerbated lung tissue damage and increased mortality rate. Overall, these findings indicate that Rab26 plays a crucial role in sepsis-induced macrophage immunosuppression by regulating macrophage ferroptosis and polarization. Hence, it represents a potential novel target for sepsis therapy.
Insights
Rab26 deficiency in macrophages worsens sepsis by promoting ferroptosis and M2 polarization, increasing susceptibility to secondary infections and mortality. Targeting Rab26 may offer a novel sepsis therapy.
Area of Science:
- Immunology
- Cell Biology
- Molecular Medicine
Background:
- Macrophage dysfunction contributes significantly to sepsis mortality, particularly secondary infections during immunosuppression.
- The specific role of Rab26 in sepsis-induced macrophage dysfunction and immunosuppression is currently unclear.
Purpose of the Study:
- To investigate the role of Rab26 in sepsis-induced macrophage immunosuppression.
- To explore the mechanisms by which Rab26 influences macrophage polarization and ferroptosis during sepsis.
- To evaluate the therapeutic potential of targeting Rab26 in sepsis.
Main Methods:
- Assessed Rab26 expression in macrophages during sepsis.
- Investigated the effect of Rab26 deficiency on macrophage polarization (M1/M2).
- Examined the impact of Rab26 on ferroptosis markers (GPX4, lipid ROS, MDA, ferrous iron) and susceptibility to secondary infections in a mouse model.
Main Results:
- Rab26 expression decreased in macrophages during sepsis, suppressed by high HMGB1.
- Rab26 deficiency promoted M2 polarization and ferroptosis in macrophages.
- Rab26 deficiency led to GPX4 degradation, increased lipid ROS, MDA, and ferrous iron, exacerbating ferroptosis.
- Rab26-deficient mice showed increased susceptibility to secondary infections, lung damage, and mortality during sepsis.
Conclusions:
- Rab26 plays a critical role in regulating macrophage ferroptosis and polarization during sepsis-induced immunosuppression.
- Rab26 deficiency exacerbates sepsis outcomes by promoting ferroptosis and susceptibility to secondary infections.
- Rab26 represents a potential novel therapeutic target for sepsis treatment.
