Yu-Sen Chai1, Yan-Qing Chen1, Shi-Hui Lin1, Ke Xie1, Chuan-Jiang Wang1, Yuan-Zheng Yang2, Fang Xu3. 1. Department of Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China. 2. Department of Critical Care Medicine, The First Affiliated Hospital of Hainan Medical University, Hainan, China. Electronic address: hhyangyuanzheng@163.com. 3. Department of Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China. Electronic address: xufang828@126.com.
Abstract
OBJECTIVES: Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is one type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Curcumin has been reported to be an anti-inflammatory factor through enhancing the function of regulatory T cells (Tregs). This study aimed to explore the effect of curcumin on the differentiation of Tregs and the role of curcumin in ALI/ARDS. METHODS: A cecal ligation and puncture (CLP)-induced acute lung injury mouse model was used to explore the effect of curcumin in ALI/ARDS. The severity of lung injury was evaluated. Immunohistochemistry of IL-17A and MPO in lung tissue was examined. Treg-related cytokine levels in serum and bronchoalveolar lavage fluid (BALF) were tested. The expression of nuclear factor-kappa B (NF-κB) in lung tissue was detected. Macrophages in lung tissue were detected by immunofluorescence. Splenic CD4+CD25+FOXP3+ Tregs were quantified, and the differentiation of Tregs from naïve CD4 + T cell and STAT5 was evaluated. The expression of IL-10 during naïve CD4 + T cell differentiation in vitro was tested. RESULTS: Curcumin alleviated lung injury in the induced CLP mouse model and suppressed inflammation. IL-17A, MPO-producing neutrophils, and NF-κB p65 expression in lungs of CLP mice decreased significantly after pretreatment with curcumin. We found curcumin could regulate M1/M2 macrophage levels in lungs of CLP mice. This may have been through regulating the differentiation of Tregs and the production of Treg-derived IL-10. Treg-derived IL-10 is the main factor that could affect macrophage polarization. We found curcumin could increase Treg proportions in vivo and up-regulate IL-10 expression in serum and BALF of CLP mice. In our in vitro experiments, we found curcumin could promote Treg differentiation and increase the production of IL-10. CONCLUSIONS: Curcumin can reduce the degree of severity of ALI and uncontrolled inflammation through promoting the differentiation of naïve CD4 + T cells to CD4+ CD25+ FOXP3+ Tregs. Curcumin promotes the conversion of macrophages from M1 to M2. The differentiation of Tregs induced by curcumin may be one source of IL-10 immune modulation.
OBJECTIVES: Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is one type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Curcumin has been reported to be an anti-inflammatory factor through enhancing the function of regulatory T cells (Tregs). This study aimed to explore the effect of curcumin on the differentiation of Tregs and the role of curcumin in ALI/ARDS. METHODS: A cecal ligation and puncture (CLP)-induced acute lung injurymouse model was used to explore the effect of curcumin in ALI/ARDS. The severity of lung injury was evaluated. Immunohistochemistry of IL-17A and MPO in lung tissue was examined. Treg-related cytokine levels in serum and bronchoalveolar lavage fluid (BALF) were tested. The expression of nuclear factor-kappa B (NF-κB) in lung tissue was detected. Macrophages in lung tissue were detected by immunofluorescence. Splenic CD4+CD25+FOXP3+ Tregs were quantified, and the differentiation of Tregs from naïve CD4 + T cell and STAT5 was evaluated. The expression of IL-10 during naïve CD4 + T cell differentiation in vitro was tested. RESULTS:Curcumin alleviated lung injury in the induced CLP mouse model and suppressed inflammation. IL-17A, MPO-producing neutrophils, and NF-κB p65 expression in lungs of CLP mice decreased significantly after pretreatment with curcumin. We found curcumin could regulate M1/M2 macrophage levels in lungs of CLP mice. This may have been through regulating the differentiation of Tregs and the production of Treg-derived IL-10. Treg-derived IL-10 is the main factor that could affect macrophage polarization. We found curcumin could increase Treg proportions in vivo and up-regulate IL-10 expression in serum and BALF of CLP mice. In our in vitro experiments, we found curcumin could promote Treg differentiation and increase the production of IL-10. CONCLUSIONS:Curcumin can reduce the degree of severity of ALI and uncontrolled inflammation through promoting the differentiation of naïve CD4 + T cells to CD4+ CD25+ FOXP3+ Tregs. Curcumin promotes the conversion of macrophages from M1 to M2. The differentiation of Tregs induced by curcumin may be one source of IL-10 immune modulation.