Knockdown of Long Noncoding RNAs of Maternally Expressed 3 Alleviates Hyperoxia-Induced Lung Injury via Inhibiting Thioredoxin-Interacting Protein-Mediated Pyroptosis by Binding to miR-18a.

Long-term hyperoxia exposure may cause lung damage with characteristic inflammation. Long noncoding RNA of maternally expressed 3 (MEG3) is up-regulated in lung tissues exposed to hyperoxia; however, the underlying mechanism is unclear. Hyperoxia-induced cells and mouse models were used to study these mechanisms. Molecular assays were used to detect cell viability, cytotoxicity, and expression of miR-18a, MEG3, and inflammatory cytokines. The interaction among MEG3, miR-18a, and thioredoxin-interacting protein (TXNIP) was verified; and pyroptosis-related proteins were analyzed. The in vivo model was established by exposing MEG3 knockdown mice to hyperoxia. Hematoxylin and eosin staining was used to assess pathologic alterations of lung tissues. Hyperoxia suppressed cell viability, induced cell damage, and exacerbated the secretion of IL-1ß and IL-18. Hyperoxia inhibited miR-18a, with increased expression of MEG3, TXNIP, and nonobese diabetic-like receptor family pyrin domain containing 3 (NLRP3). MEG3 aggravated TXNIP expression by binding to miR-18a. Knockdown of MEG3 rescued hyperoxia-induced pyroptosis by up-regulating miR-18a. Furthermore, knockdown of MEG3 inhibited NLRP3 inflammasome activity and caspase-1 signaling by miR-18a. In vivo knockdown of MEG3 and overexpression of miR-18a relieved hyperoxia-induced lung injury via restraining NLRP3 inflammasome-mediated pyroptosis, whereas miR-18a inhibition reversed these effects. In conclusion, knockdown of MEG3 inhibits pyroptosis to alleviate hyperoxia lung injury by suppressing NLRP3 inflammasome and caspase-1 signaling via regulating miR-18a-TXNIP axis.

Roles of the mammalian target of rapamycin (mTOR) signaling pathway in the repair of hyperoxia-induced acute lung injury.

BACKGROUND: Rapamycin inhibits the mammalian target of rapamycin (mTOR) activity and has been proven effective for the treatment of lung injury. OBJECTIVES: The objective of this study was to investigate the roles of the mTOR pathway and its inhibitor rapamycin in the repair of hyperoxia-induced acute lung injury (ALI). MATERIAL AND METHODS: Firstly, premature rat lung fibroblast L929 cells were cultured under different oxygen concentrations (40%, 60%, and 90%). At day 3, 7 and 14 after exposure, MTT assay and flow cytometry were used to evaluate the effect of oxygen stress on cell viability and apoptosis of L929 cells, respectively. Secondly, microscopy, MTT assay and flow cytometry was used to investigate the effect of 10 nM rapamycin on 90% O2 exposed L929 cells. We also used small interfering RNAs (siRNAs) to abrogate the expression of mTOR in 90% O2 exposed L929 cells, and then evaluated the apoptosis and cell viability using flow cytometry and the MTT assay, respectively. In addition, western blot was used to detect the protein expression of Bcl-2, p53, TGF-ß and connective tissue growth factor (CTGF). A hyperoxia-induced lung injury model was established in Sprague Dawley (SD) rats in order to evaluate the histopathological changes in lung tissues and expression of the mTOR pathway and fibrosis related factors. RESULTS: Exposure to 40%, 60% or 90% oxygen all significantly inhibited the growth of L929 cells. Application of 10 nM rapamycin was found to effectively promote apoptosis of 90% O2 exposed L929 cells. In addition, mTOR siRNA promoted the apoptosis and inhibited the growth of L929 cells. Rapamycin inhibited the activation of the mTOR signaling pathway, down-regulated the expression of downstream proteins p70S6K and 4EBP1, reduced the collagen deposition and the production of fibrosis-inducing factors, including TGF-ß and CTGF in hyperoxia-induced lung injury rats. CONCLUSIONS: Rapamycin may be useful for the treatment of hyperoxia-induced acute lung injury (ALI) by inhibiting the activation of mTOR signaling pathway.

Clinical characteristics and prognostic factors in Chinese patients with classical Hodgkin's lymphoma involving extranodal sites: a retrospective single-center.

Objectives: To analyze the clinical characteristics and prognostic factors in Chinese patients with classical Hodgkin's lymphoma (cHL) involving extranodal sites. Methods: Clinical features and outcomes of 68 patients diagnosed with cHL involving extranodal sites from April 2003 to November 2017 were analyzed retrospectively. The data was compared with that of 76 cHL patients without extranodal involvement in the same period. Results: (1) Extranodal involvement was common in Chinese cHL patients. The most common sites were lung (44.1%) and bone (33.8%), followed by bone marrow, liver, pericardium, pleura and other sites. (2) With a median follow-up period of 4.58 years, the 5-year overall survival (OS) of 68 patients with extranodal involvement was significantly poorer than that of 76 patients with only nodal involvement (81.4% vs. 92.8%, p = 0.018). (3) In univariate analysis, lymphocytopenia (p = 0.027), elevated lactate dehydrogenase (LDH) (p = 0.026) and involved lymph node region (LNR) ≥4 (p = 0.044) predicted inferior freedom from progression (FFP) with significant difference. Elder age (p = 0.010), elevated LDH (p = 0.013), elevated platelet (p = 0.044), involved LNR ≥ 4 (p = 0.047) were also statistically significant in OS. Extranodal sites and number of extranodal sites showed no significant difference in FFP and OS. Factors with p-value smaller than 0.100 were evaluated in multivariate analysis, turning out that lymphocytopenia was the only independent adverse prognostic factor in FFP (p = 0.039; HR = 2.595) and OS (p = 0.028; HR = 4.993). Conclusion: Extranodal involvement was frequent in Chinese cHL patients, with lung to be the most commonly involved site. Lymphocytopenia was the only independent adverse prognostic factor.

Relationship between Hepatitis C Virus Infection and Iron Overload.

OBJECTIVE: The aim of this study was to summarize the interactions between hepatitis C virus (HCV) infection and iron overload, and to understand the mechanisms of iron overload in chronic hepatitis C (CHC) and the role iron plays in HCV life cycle. DATA SOURCES: This review was based on data in articles published in the PubMed databases up to January 28, 2017, with the keywords "hepatitis C virus", "iron overload", "iron metabolism", "hepcidin", "translation", and "replication". STUDY SELECTION: Articles related to iron metabolism, iron overload in patients with CHC, or the effects of iron on HCV life cycle were selected for the review. RESULTS: Iron overload is common in patients with CHC. The mechanisms involve decreased hepcidin levels caused by HCV through signal transducer and activator of transcription 3, mitogen-activated protein kinase, or bone morphogenetic protein/SMAD signaling pathways, and the altered expression of other iron-metabolism-related genes. Some studies found that iron increases HCV replication, while other studies found the opposite result. Most of the studies suggest the positive role of iron on HCV translation, the mechanisms of which involve increased expression levels of factors associated with HCV internal ribosome entry site-dependent translation, such as eukaryotic initiation factor 3 and La protein. CONCLUSION: The growing literature demonstrates that CHC leads to iron overload, and iron affects the HCV life cycle in turn. Further research should be conducted to clarify the mechanism involved in the complicated interaction between iron and HCV.

Improvement of chronic hepatitis B by iron chelation therapy in a patient with iron overload: A case report.

RATIONALE: This report describes seroconversion of hepatitis B surface antigen (HBsAg) in a patient with marked iron overload caused by chronic hepatitis B (CHB) after receiving iron chelation therapy and discusses the role of iron chelation therapy in CHB. PATIENT CONCERNS: Increased serum ferritin level for 2 months. DIAGNOSIS: Secondary iron overload and CHB. INTERVENTION: To relieve iron load of the body, the patient underwent regular phlebotomy therapy and deferoxamine (DFO) therapy. During the therapy, serum ferritin and hepatitis B virus (HBV) were monitored and the iron concentration of the liver and heart were followed by T2* of magnetic resonance imaging (MRI) scan. OUTCOMES: Serum ferritin gradually decreased. Approximately 1 year after the therapy, HBsAg turned persistently negative. LESSONS: Iron chelation therapy may attenuate HBV infection.