ABSTRACT
BACKGROUND: Obliterative bronchiolitis (OB) remains the major complication limiting long-term survival of patients after lung transplantation. We aimed to explore the effects of the selective NACHT, LRR, and PYD domains-containing protein 3 (Nlrp3) inflammasome inhibitor MCC950 on the pathogenesis of OB. METHODS: Mouse orthotopic tracheal transplants were performed to mimic OB. MCC950 (50 mg/kg) or saline was intraperitoneally injected daily. The luminal occlusion rate and collagen deposition were evaluated by hematoxylin and eosin and Masson's trichrome staining, respectively. Infiltration of CD4+, CD8+ T cells, and neutrophils was detected with immunohistochemical staining. The frequencies of T helper 1 cell (Th1), T helper 17 cell (Th17), and regulatory T cells (Treg) were measured by flow cytometry. Cytokine levels were measured by ELISA kits. RESULTS: MCC950 treatment significantly inhibited Nlrp3 inflammasome activation after allogeneic tracheal transplant and markedly decreased the luminal occlusion rate and collagen deposition in the allograft. The numbers of infiltrating CD4+, CD8+ T cells, and neutrophils in the allograft were also significantly reduced by MCC950 treatment. MCC950 dramatically decreased the frequencies of Th1/Th17 cells and the levels of interferon gamma/interleukin (IL)-17A and increased the Treg cell frequencies and IL-10 level; however, these effects were abolished by the addition of IL-1ß and IL-18 both in vitro and in vivo. OB was also rescued by the addition of IL-1ß and/or IL-18. CONCLUSIONS: Blocking Nlrp3 inflammasome activation with MCC950 ameliorates OB lesions. The mechanistic analysis showed that MCC950 regulated the balance of Th1/Th17 and Treg cells and that this process is partially mediated by inhibition of IL-1ß and IL-18. Therefore, targeting the Nlrp3 inflammasome is a promising strategy for controlling OB after lung transplantation.
Subject(s)
Bronchiolitis Obliterans/drug therapy , Heterocyclic Compounds, 4 or More Rings/pharmacology , Inflammasomes/antagonists & inhibitors , Lung Transplantation/adverse effects , Postoperative Complications/drug therapy , Sulfones/pharmacology , Animals , Bronchiolitis Obliterans/immunology , Disease Models, Animal , Furans , Heterocyclic Compounds, 4 or More Rings/therapeutic use , Humans , Indenes , Inflammasomes/immunology , Male , Mice , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Postoperative Complications/immunology , Sulfonamides , Sulfones/therapeutic use , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/immunology , Th1 Cells/drug effects , Th1 Cells/immunology , Th17 Cells/drug effects , Th17 Cells/immunology , Trachea/transplantationABSTRACT
Lung ischemia-reperfusion (IR) occurs in many circumstances and leads to impaired lung function. The NACHT, LRR and PYD domains-containing protein 3 (Nlrp3) inflammasome is reportedly activated during lung IR. Mcc950 is a recently developed Nlrp3 inhibitor. The aim of our study was to test the efficacy of Mcc950 on lung IR injury and to investigate the role of reactive oxygen species (ROS) in Nlrp3 inflammasome activation using a murine lung IR model. The results of the current study confirmed that Nlrp3 was upregulated and activated during lung IR, and inhibiting oxidative stress by the ROS scavenger edaravone attenuated Nlrp3 inflammasome activation. Mcc950 pretreatment significantly alleviated IR-induced lung injury by reducing production of the proinflammatory cytokines Il-1ß and Il-18 and inhibiting neutrophil infiltration and cell apoptosis. Protein coimmunoprecipitation revealed that Mcc950 partially blocked the interaction between Nlrp3 and Nek7 (NimA-related protein kinase 7). Therefore, we conclude that ROS-dependent activation of the Nlrp3 inflammasome contributed to lung IR injury. Mcc950 significantly reduced lung IR injury by blocking Nlrp3 inflammasome activation, and the mechanism was partially attributed to inhibition of the interaction between Nlrp3 and Nek7. Thus, Mcc950 is a promising treatment for the prevention of lung IR injury.
Subject(s)
Anti-Inflammatory Agents/therapeutic use , Inflammasomes/antagonists & inhibitors , Lung Injury/drug therapy , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Pneumonia/drug therapy , Reperfusion Injury/drug therapy , Animals , Inflammasomes/analysis , Inflammasomes/immunology , Interleukin-18/analysis , Interleukin-18/immunology , Interleukin-1beta/analysis , Interleukin-1beta/immunology , Lung Injury/immunology , Lung Injury/pathology , Male , Mice, Inbred C57BL , NLR Family, Pyrin Domain-Containing 3 Protein/analysis , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Neutrophil Infiltration/drug effects , Pneumonia/immunology , Pneumonia/pathology , Reactive Oxygen Species/immunology , Reperfusion Injury/immunology , Reperfusion Injury/pathologyABSTRACT
14-3-3ζ is overexpressed in several cancers, including esophageal squamous cell carcinoma (ESCC), and plays an important role in tumorigenesis. However, the mechanisms underlying its tumorigenesis remain unclear. Here we report that 14-3-3ζ was upregulated in ESCC tumors, compared with adjacent normal tissues; 14-3-3ζ levels were positively correlated with ESCC lymph node metastasis and recurrence. Overexpression of 14-3-3ζ promoted the tumor growth and invasion of ESCC in vitro and in vivo, whereas depletion of 14-3-3ζ suppressed these effects. Moreover, 14-3-3ζ reduces expression of genes mediating S1P/S1PR2 signaling, and this effect is mediated through activation of NF- κ B. Taken together, 14-3-3ζ contributes to ESCC tumorigenesis and progression through repressing S1PR2 signaling and may act as a new therapeutic target for ESCC.
