RESUMO
Background: As a damage-associated molecular pattern, the myeloid-related protein 8/14 (MRP8/14) heterodimer mediates various inflammatory diseases, such as sepsis. However, how MRP8/14 promotes lung injury by regulating the inflammatory response during endotoxemia remains largely unknown. This study aims at illuminating the pathological functions of MRP8/14 in endotoxemia. Methods: An endotoxemic model was prepared with wild-type and myeloid cell-specific Mrp8 deletion (Mrp8ΔMC) mice for evaluating plasma cytokine levels. Lung injury was evaluated by hematoxylin and eosin (H&E) staining, injury scoring and wet-to-dry weight (W/D) ratio. The dynamic profile of interferon γ (IFNγ)-inducible protein 10 (IP-10) mRNA expression induced by macrophage MRP8/14 was determined by quantitative real-time polymerase chain reaction (qPCR). Immunoblotting was used to evaluate the increase in IP-10 level induced by activation of the JAK-STAT signaling pathway. Luciferase reporter assay was performed to detect the involvement of IRF7 in Ip-10 gene transcription. In vivo air pouch experiments were performed to determine the biological function of IP-10 induced by MRP8/14. Results: Experiments with Mrp8ΔMC mice showed that MRP8/14 promoted the production of cytokines, including IP-10, in the bronchoalveolar lavage fluid (BALF) and lung injury in endotoxic mice. The result of qPCR showed sustained expression of Ip-10 mRNA in macrophages after treatment with MRP8/14 for 12 h. Neutralization experiments showed that the MRP8/14-induced Ip-10 expression in RAW264.7 cells was mediated by extracellular IFNß. Western blotting with phosphorylation-specific antibodies showed that the JAK1/TYK2-STAT1 signaling pathway was activated in MRP8/14-treated RAW264.7 cells, leading to the upregulation of Ip-10 gene expression. IRF7 was further identified as a downstream regulator of the JAK-STAT pathway that mediated Ip-10 gene expression in macrophages treated with MRP8/14. In vivo air pouch experiments confirmed that the IFNß-JAK1/TYK2-STAT1-IRF7 pathway was required for chemokine (C-X-C motif) receptor 3 (CXCR3)+ T lymphocyte migration, which promoted lung injury in the context of endotoxemia. Conclusions: In summary, our study demonstrates that MRP8/14 induces sustained production of IP-10 via the IFNß-JAK1/TYK2-STAT1-IRF7 pathway to attract CXCR3+ T lymphocytes into lung tissues and ultimately results in lung injury by an excessive inflammatory response in the context of endotoxemia.
RESUMO
PURPOSE: To explore the clinicopathological features of sclerosing angiomatoid nodular transformation (SANT) of the spleen. METHODS: The clinicopathological data of 26 SANT patients were analyzed. RESULT: There were 15 men and 11 women, aged 23-62 years (mean: 43.9 years; median: 43 years). Twenty patients were found during health check-ups. Magnetic resonance imaging had significantly higher specificity than other imaging modes in the diagnosis of SANT. Macroscopically, the lesions were gray-red and gray-white, along with well-demarcated nodules. Microscopy showed multiple angiomatoid nodules embedded in hyperplastic fibrous tissues and dense collagen fiber; the angiomatoid structures inside the nodules had varied morphology. Patchy and nodular fresh and old hemorrhages were observed in each lesion. Proliferative fibroblasts were seen in the stroma, along with infiltration of a few mixed inflammatory cells. Serum tumor markers were negative. Fourteen patients (53.8 %) had benign or malignant lesions in other parts of the body, including the liver, kidneys, and adrenal and pituitary glands which were similar to von Hippel-Lindau (VHL) syndrome. The reasons for occurrence of SANT may be as follows: hemangioma/lymphangioma or splenic congestion with extensive hemorrhage and secondary changes. CONCLUSIONS: SANT is a rare benign vascular lesion with some clinical manifestations similar to VHL syndrome. Patients have good prognosis after tumor removal.
