Image_1_MCC950 Ameliorates Acute Liver Injury Through Modulating Macrophage Polarization and Myeloid-Derived Suppressor Cells Function.JPEG

Acute liver injury (ALI) raises high mortality rates due to a rapid pathological process. MCC950, a highly selective nod-like receptor family pyrin domain containing 3 (NLRP3) inhibitor, has already been reported to show strong hepatoprotective effects in many different liver diseases. In this study, we unveiled the role of MCC950 in carbon tetrachloride (CCl4)-induced ALI and its underlying molecular mechanisms on days 1, 2, and 3. MCC950 could significantly inhibit liver injury, evidenced by decreased serum alamine aminotransferase (ALT) and aspartate aminotransferase (AST) levels on days 1 and 2, increased Albumin (ALB) level on day 3, and decreased histological score during the whole period. Moreover, lower M1 macrophage related to pro-inflammatory genes expression was observed in MCC950-treated ALI mice on day 1, while MCC950 pretreatment also polarized macrophage to M2 phenotype indicating anti-inflammatory response on days 2 and 3. Additionally, MDSC was significantly increased in blood, liver, and spleen in ALI mice at different time courses. Specifically, upregulated myeloid-derived suppressor cell (MDSC) proportions were found in blood and spleen on days 1 and 2, but showed decreased trend on day 3. However, liver MDSC numbers were increased on days 2 and 3, but no significance on day 1. In conclusion, MCC950 pretreatment alleviates CCl4-induced ALI through enhanced M2 macrophage and MDSC function at different time points of ALI. Further understanding of MCC950 in ALI may be a new potential therapeutic strategy.</p

Image_2_Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma.tif

BackgroundDespite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.ObjectivesWe sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.MethodsCockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.ResultsCockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.ConclusionsThese results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.</p

Image_1_Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma.tif

BackgroundDespite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.ObjectivesWe sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.MethodsCockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.ResultsCockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.ConclusionsThese results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.</p

DataSheet_1_Type II alveolar epithelial cell aryl hydrocarbon receptor protects against allergic airway inflammation through controlling cell autophagy.pdf

RationaleAryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, has been considered as an important regulator for immune diseases. We have previously shown that AhR protects against allergic airway inflammation. The underlying mechanism, however, remains undetermined.ObjectivesWe sought to determine whether AhR specifically in type II alveolar epithelial cells (AT2) modulates allergic airway inflammation and its underlying mechanisms.MethodsThe role of AhR in AT2 cells in airway inflammation was investigated in a mouse model of asthma with AhR conditional knockout mice in AT2 cells (Sftpc-Cre;AhRf/f). The effect of AhR on allergen-induced autophagy was examined by both in vivo and in vitro analyses. The involvement of autophagy in airway inflammation was analyzed by using autophagy inhibitor chloroquine. The AhR-regulated gene profiling in AT2 cells was also investigated by RNA sequencing (RNA-seq) analysis.ResultsSftpc-Cre;AhRf/f mice showed exacerbation of allergen-induced airway hyperresponsiveness and airway inflammation with elevated Th2 cytokines in bronchoalveolar lavage fluid (BALF). Notably, an increased allergen-induced autophagy was observed in the lung tissues of Sftpc-Cre;AhRf/f mice when compared with wild-type mice. Further analyses suggested a functional axis of AhR-TGF-β1 that is critical in driving allergic airway inflammation through regulating allergen-induced cellular autophagy. Furthermore, inhibition of autophagy with autophagy inhibitor chloroquine significantly suppressed cockroach allergen–induced airway inflammation, Th2 cytokines in BALFs, and expression of autophagy-related genes LC3 and Atg5 in the lung tissues. In addition, RNA-seq analysis suggests that autophagy is one of the major pathways and that CALCOCO2/NDP52 and S1009 are major autophagy-associated genes in AT2 cells that may contribute to the AhR-mediated cockroach allergen–induced airway inflammation and, subsequently, allergic asthma.ConclusionThese results suggest that AhR in AT2 cells functions as a protective mechanism against allergic airway inflammation through controlling cell autophagy.</p

Image_3_Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma.tif

BackgroundDespite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.ObjectivesWe sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.MethodsCockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.ResultsCockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.ConclusionsThese results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.</p

Image_5_Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma.tif

BackgroundDespite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.ObjectivesWe sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.MethodsCockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.ResultsCockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.ConclusionsThese results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.</p

Image_4_Epithelial Aryl Hydrocarbon Receptor Protects From Mucus Production by Inhibiting ROS-Triggered NLRP3 Inflammasome in Asthma.tif

BackgroundDespite long-standing recognition in the significance of mucus overproduction in asthma, its etiology remains poorly understood. Muc5ac is a secretory mucin that has been associated with reduced pulmonary function and asthma exacerbations.ObjectivesWe sought to investigate the immunological pathway that controls Muc5ac expression and allergic airway inflammation in asthma.MethodsCockroach allergen-induced Muc5ac expression and aryl hydrocarbon receptor (AhR) signaling activation was examined in the human bronchial epithelial cells (HBECs) and mouse model of asthma. AhR regulation of Muc5ac expression, mitochondrial ROS (Mito-ROS) generation, and NLRP3 inflammasome was determined by AhR knockdown, the antagonist CH223191, and AhR-/- mice. The role of NLRP3 inflammasome in Muc5ac expression and airway inflammation was also investigated.ResultsCockroach allergen induced Muc5ac overexpression in HBECs and airways of asthma mouse model. Increased expression of AhR and its downstream genes CYP1A1 and CYP1B1 was also observed. Mice with AhR deletion showed increased allergic airway inflammation and MUC5AC expression. Moreover, cockroach allergen induced epithelial NLRP3 inflammasome activation (e.g., NLRP3, Caspase-1, and IL-1β), which was enhanced by AhR knockdown or the antagonist CH223191. Furthermore, AhR deletion in HBECs led to enhanced ROS generation, particularly Mito-ROS, and inhibition of ROS or Mito-ROS subsequently suppressed the inflammasome activation. Importantly, inhibition of the inflammasome with MCC950, a NLRP3-specifc inhibitor, attenuated allergic airway inflammation and Muc5ac expression. IL-1β generated by the activated inflammasomes mediated cockroach allergen-induced Muc5ac expression in HBECs.ConclusionsThese results reveal a previously unidentified functional axis of AhR-ROS-NLRP3 inflammasome in regulating Muc5ac expression and airway inflammation.</p

DataSheet_2_Type II alveolar epithelial cell aryl hydrocarbon receptor protects against allergic airway inflammation through controlling cell autophagy.xlsx

RationaleAryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, has been considered as an important regulator for immune diseases. We have previously shown that AhR protects against allergic airway inflammation. The underlying mechanism, however, remains undetermined.ObjectivesWe sought to determine whether AhR specifically in type II alveolar epithelial cells (AT2) modulates allergic airway inflammation and its underlying mechanisms.MethodsThe role of AhR in AT2 cells in airway inflammation was investigated in a mouse model of asthma with AhR conditional knockout mice in AT2 cells (Sftpc-Cre;AhRf/f). The effect of AhR on allergen-induced autophagy was examined by both in vivo and in vitro analyses. The involvement of autophagy in airway inflammation was analyzed by using autophagy inhibitor chloroquine. The AhR-regulated gene profiling in AT2 cells was also investigated by RNA sequencing (RNA-seq) analysis.ResultsSftpc-Cre;AhRf/f mice showed exacerbation of allergen-induced airway hyperresponsiveness and airway inflammation with elevated Th2 cytokines in bronchoalveolar lavage fluid (BALF). Notably, an increased allergen-induced autophagy was observed in the lung tissues of Sftpc-Cre;AhRf/f mice when compared with wild-type mice. Further analyses suggested a functional axis of AhR-TGF-β1 that is critical in driving allergic airway inflammation through regulating allergen-induced cellular autophagy. Furthermore, inhibition of autophagy with autophagy inhibitor chloroquine significantly suppressed cockroach allergen–induced airway inflammation, Th2 cytokines in BALFs, and expression of autophagy-related genes LC3 and Atg5 in the lung tissues. In addition, RNA-seq analysis suggests that autophagy is one of the major pathways and that CALCOCO2/NDP52 and S1009 are major autophagy-associated genes in AT2 cells that may contribute to the AhR-mediated cockroach allergen–induced airway inflammation and, subsequently, allergic asthma.ConclusionThese results suggest that AhR in AT2 cells functions as a protective mechanism against allergic airway inflammation through controlling cell autophagy.</p