Zhongmei Wen

Xanthohumol ameliorates lipopolysaccharide (LPS)-induced acute lung injury via induction of AMPK/GSK3β-Nrf2 signal axis

Abundant natural flavonoids can induce nuclear factor-erythroid 2 related factor 2 (Nrf2) and/or AMP-activated protein kinase (AMPK) activation, which play crucial roles in the amelioration of various inflammation- and oxidative stress-induced diseases, including acute lung injury (ALI). Xanthohumol (Xn), a principal prenylflavonoid, possesses anti-inflammation and anti-oxidant activities. However, whether Xn could protect from LPS-induced ALI through inducing AMPK/Nrf2 activation and its downstream signals, are still poorly elucidated. Accordingly, we focused on exploring the protective effect of Xn in the context of ALI and the involvement of underlying molecular mechanisms. Our findings indicated that Xn effectively alleviated lung injury by reduction of lung W/D ratio and protein levels, neutrophil infiltration, MDA and MPO formation, and SOD and GSH depletion. Meanwhile, Xn significantly lessened histopathological changes, reactive oxygen species (ROS) generation, several cytokines secretion, and iNOS and HMGB1 expression, and inhibited Txnip/NLRP3 inflammasome and NF-κB signaling pathway activation. Additionally, Xn evidently decreased t-BHP-stimulated cell apoptosis, ROS generation and GSH depletion but increased various anti-oxidative enzymes expression regulated by Keap1-Nrf2/ARE activation, which may be associated with AMPK and GSK3β phosphorylation. However, Xn-mediated inflammatory cytokines and ROS production, histopathological changes, Txnip/NLRP3 inflammasome and NF-κB signaling pathway in WT mice were remarkably abrogated in Nrf2-/- mice. Our experimental results firstly provided a support that Xn effectively protected LPS-induced ALI against oxidative stress and inflammation damage which are largely dependent upon upregulation of the Nrf2 pathway via activation of AMPK/GSK3β, thereby suppressing LPS-activated Txnip/NLRP3 inflammasome and NF-κB signaling pathway.

Consumption of, and factors influencing consumption of, fruit and vegetables among elderly Chinese people.

OBJECTIVE There is substantial evidence that the low intake of fruit and vegetables (FV) is a major risk factor for many nutrition-related non-communicable diseases. The purpose of our study was to assess FV consumption and the variables that influence FV consumption among Chinese people age 60 and older. METHODS Twenty-four-hour dietary recall data from the 1991, 1993, 1997, 2000, 2004, 2006, and 2009 China Health and Nutrition Surveys were used to collect the FV intake and sociodemographic variables examined in this article. Data were analyzed using t tests, χ(2) tests, and logistic regression. RESULTS Between 1991 and 2009, elderly Chinese adults experienced an improvement in dietary FV intake. The FV consumption increased from 325.7 g/d in 1991 to 379.0 g/d in 2009. During this 18-y period, the proportion of daily consumers increased from 11.0% to 32.5% for fruit and remained over 95% for vegetables. Age, gender, educational attainment, community, activity level, marital status, and drinking were significantly associated with FV consumption. CONCLUSION The findings of this study indicated that FV intake among elderly adults in China was lower than the minimum of 400 g/d recommended by the World Health Organization. Greater public health efforts and approaches are needed to promote FV consumption in elderly Chinese adults.

Butein induces cell apoptosis and inhibition of cyclooxygenase‑2 expression in A549 lung cancer cells.

Butein is a flavonoid isolated from the bark of Rhus verniciflua Stokes and the flowers of Butea monosperma, and is known to be a potential therapeutic drug for treating inflammation and cancer. Cyclooxygenase (COX) converts arachidonic acid to prostanoids, and increased expression of its isoform, COX‑2, has been observed in lung cancer tissue. The aim of the present study was to investigate expression alteration of COX‑2 in A549 lung cancer cells following butein treatment at the mRNA and protein levels by quantitative polymerase chain reaction and western blotting, respectively. It was observed that COX‑2 mRNA and protein levels were significantly downregulated in the butein treatment group in comparison with the control group (P<0.05). In addition, the effects of butein on proliferation and apoptosis were evaluated. The data demonstrated that butein induces cell‑cycle arrest and apoptosis in human lung cancer cells. These results indicated that butein may be a promising candidate drug for lung cancer treatment.

Esculentoside A Attenuates Allergic Airway Inflammation via Activation of the Nrf-2 Pathway

Background: The role of airway inflammation and inflammation-induced oxidative stress in the pathogenesis and progression of chronic inflammatory airway diseases has received increasing attention in recent years. We investigated the potential anti-inflammatory and antioxidative effects of esculentoside A (EsA), a saponin isolated from the Chinese herb Phytolacca esculenta, in comparison to dexamethasone, a potent corticosteroid, in a murine model of allergic asthma. Methods: EsA was added to cultures of A549 cells at different concentrations or for different lengths of time, and nuclear factor erythroid 2-related factor 2 (Nrf-2) translocation and heme oxygenase 1 expression were monitored. Mice treated with or without EsA and Nrf-2 siRNA were sensitized and challenged with ovalbumin (OVA) and developed airway inflammation and oxidative lung damage. The Th2-type cytokine levels and inflammatory cells in bronchoalveolar lavage fluid (BALF) and the serum immunoglobulin production and adhesion molecule expression in the lung tissues were measured. The activities of related antioxidases and glutathione were measured using assay kits. Results: EsA enhanced nuclear Nrf-2 translocation in both A549 cells and the lungs of OVA-challenged mice. Airway inflammation induced by OVA was reduced. Additionally, EsA increased mRNA expression of antioxidant enzymes regulated by Nrf-2, leading to a reduction in Th2 cytokines and the expression of adhesion molecule mRNA in the BALF and lung tissues. Inhibition of Nrf-2 by siRNA abrogated the regulatory effects of EsA on inflammation and oxidant stress. Conclusions: This is the first study to illustrate that EsA acts as a novel Nrf-2 activator, which modulates the oxidative stress pathway to improve lung injury and ameliorate the development of airway inflammation.

ADAM17 silencing suppresses the migration and invasion of non-small cell lung cancer.

A disintegrin and metalloprotease (ADAM) 17 has been implicated in the tumor progression of various types of solid tumor; however, little is known about its role in non-small cell lung carcinoma (NSCLC). The present study evaluated whether the downregulation of ADAM17 affects cell proliferation, the cell cycle, cell migration and cell invasion in NSCLC. A recombinant lentiviral small hairpin RNA (shRNA) expression vector carrying ADAM17 was constructed and then infected into A549 cells, a human NSCLC cell line. Cell proliferation, cell cycle progression, cell migration and cell invasion were determined following the downregulation of ADAM17 by siRNA. It was revealed that downregulation of ADAM17 expression using an RNA silencing approach in A549 tumor cells significantly suppressed cell proliferation and invasion in vitro, and tumor growth in vivo. These data suggested that ADAM17 is an important regulator of the tumorigenic properties of human NSCLC and may be used as a potential anticancer therapeutic target in NSCLC.

Exposure to PM2.5 induces aberrant activation of NF-κB in human airway epithelial cells by downregulating miR-331 expression.

Exposure to particulate matter (PM) with an aerodynamic diameter≤2.5μm (PM2.5) induces reactive oxygen species (ROS) and pro-inflammatory cytokine production, leading to airway epithelial injury. However, the mechanisms underlying the toxicity of PM2.5 have not been clarified. Here, we show that exposure to PM2.5 induces sustained activation of the nuclear factor kappa B (NF-κB) signaling in human airway epithelial Beas-2B (B2B) cells. In addition, PM2.5 exposure significantly decreased miR-331 expression in B2B cells, which was abrogated by inhibition of ROS or phosphoinositide 3-kinase (PI3K)/Akt pathway. Induction of miR-331 overexpression attenuated the PM2.5 exposure-induced NF-kBp65 nuclear translocation, IL-6 and IL-8 expression in B2B cells. Furthermore, miR-331 targeted the inhibitor of NF-κB kinase beta (IKK-β) by down-regulating the IKK-β-regulated luciferase activity in HEK293 cells. Moreover, induction of miR-331 over-expression inhibited IKK-β expression while induction of IKK-β over-expression prevented the inhibition of miR-331 on the PM2.5 exposure-induced NF-kBp65 nuclear translocation, IL-6 and IL-8 expression in B2B cells. Therefore, PM2.5 exposure decreased miR-331 expression via the ROS/PI3K/Akt pathway, resulting in an increase in the IKK-β expression and sustained NF-κB activation in human airway epithelial cells. Our findings may provide new insights into the molecular mechanisms underlying the toxicity of PM2.5 exposure and aid in design of new therapeutic strategies to prevent PM2.5-induced toxicity.

Isoliquiritigenin Activates Nuclear Factor Erythroid-2 Related Factor 2 to Suppress the NOD-Like Receptor Protein 3 Inflammasome and Inhibits the NF-κB Pathway in Macrophages and in Acute Lung Injury

Among the cellular response mechanisms, the nuclear factor erythroid-2 related factor 2 (Nrf2) pathway is considered a survival pathway that alleviates oxidative injury, while both the NOD-like receptor protein 3 (NLRP3) and NF-κB pathways are pro-inflammatory pathways that cause damage to cells. These pathways are implicated in the development and resolution of acute lung injury (ALI). Isoliquiritigenin (ISL), a flavonoid from the liquorice compound, is suggested to be a regulator of the above pathways, but the mechanisms of how the NLRP3/NF-κB pathway interacts with Nrf2 and its protective effects in ALI remain unknown. In the present study, ISL inhibited reactive oxygen species (ROS) generation and cytotoxicity induced by t-BHP and pro-inflammatory enzymes production induced by LPS in RAW 264.7 cells. Such cytoprotective effects coincided with the induction of AMP-activated protein kinase (AMPK)/Nrf2/antioxidant response element (ARE) signaling and the suppression of the NLRP3 and NF-κB pathways. Consistent with these findings, ISL treatment significantly alleviated lung injury in LPS-induced ALI mice, which was reflected by reductions in histopathological changes, pulmonary edema, and protein leakage. At the same time, the increased levels of inflammatory cell exudation and pro-inflammatory mediators, the enhanced production of ROS, myeloperoxidase, and malondialdehyde, and the depleted expression of GSH and superoxide dismutase induced by LPS were ameliorated by ISL. Furthermore, ISL notably activated AMPK/Nrf2/ARE signaling and inhibited LPS-induced NLRP3 and NF-κB activation in the lung. Moreover, although inhibition of the LPS-induced histopathological changes and ROS production were attenuated in Nrf2-deficient mice, the repression of the NLRP3 and NF-κB pathways by ISL was Nrf2-dependent and Nrf2-independent, respectively. In conclusion, our results are the first to highlight the beneficial role and relevant mechanisms of ISL in LPS-induced ALI and provide novel insight into its application.

Alleviation of severe inflammatory responses in LPS-exposed mice by Schisantherin A.

In this study, we aimed to investigate our hypothesis starting that Schisantherin A (SchA), which exerts significant anti-inflammatory effects in vitro, could reduce the pulmonary inflammatory response in an acute lung injury (ALI) model. ALI was induced in mice by exposure to lipopolysaccharide (LPS, 20 mg/kg), and the inflammatory mediator production, neutrophil infiltration, and histopathological changes were evaluated. SchA at a dose of 100 mg/kg significantly improved survival rate of mice injected with LPS. The levels of TNF-α and IL-6 in bronchoalveolar lavage fluid (BALF) and the histopathological changes due to the injury were significantly inhibited when SchA was administered before or after LPS insult, and the infiltration of neutrophils and macrophages in lung tissues induced by LPS were suppressed by SchA. Additionally, pretreatment with SchA notably blocked the activation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPKs). Taken together, SchA showed obvious anti-inflammatory effects in an LPS-induced ALI model via blockage of the NF-κB and MAPK pathways. Thus, SchA may be an innovative therapy for inflammatory diseases.

Diosmetin Alleviates Lipopolysaccharide-Induced Acute Lung Injury through Activating the Nrf2 Pathway and Inhibiting the NLRP3 Inflammasome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common clinical syndrome of diffuse lung inflammation with high mortality rates and limited therapeutic methods. Diosmetin, an active component from Chinese herbs, has long been noticed because of its antioxidant and anti-inflammatory activities. The aim of this study was to evaluate the effects of diosmetin on LPS-induced ALI model and unveil the possible mechanisms. Our results revealed that pretreatment with diosmetin effectively alleviated lung histopathological changes, which were further evaluated by lung injury scores. Diosmetin also decreased lung wet/dry ratios, as well as total protein levels, inflammatory cell infiltration and proinflammatory cytokine (eg. TNF-α, IL-1β and IL-6) overproduction in bronchoalveolar lavage fluid (BALF). Additionally, increased MPO, MDA and ROS levels induced by LPS were also markly suppressed by diosmetin. Furthermore, diosmetin significantly increased the expression of Nrf2 along with its target gene HO-1 and blocked the activation of NLRP3 inflammasome in the lung tissues, which might be central to the protective effects of diosmetin. Further supporting these results, in vitro experiments also showed that diosmetin activated Nrf2 and HO-1, as well as inhibited the NLRP3 inflammasome in both RAW264.7 and A549 cells. The present study highlights the protective effects of diosmetin on LPS-induced ALI via activation of Nrf2 and inhibition of NLRP3 inflammasome, bringing up the hope of its application as a therapeutic drug towards LPS-induced ALI.

Strong evidence for LncRNA ZNRD1-AS1, and its functional Cis- eQTL locus contributing more to the susceptibility of lung cancer

Long noncoding RNAs (IncRNAs), involved in cancer biology, contributing to essential cancer cell functions such as proliferation, invasion, and metastasis, have received increasing attention recently. Human Zinc ribbon domain containing 1 (ZNRD1) has been confirmed to be involved in carcinogenesis and development of multiple cancers. ZNRD1-AS1, a lncRNA in the upstream region of ZNRD1 which could down-regulate the expression of ZNRD1, has been identified as a possible component in carcinogenesis. The underlying relations of ZNRD1-AS1 with lung cancer development and metastasis remain obscure. In current study, we first evaluated the expression ZNRD1-AS1 and ZNRD1 among lung cancer tissues and corresponding normal tissues, which showed higher expression of ZNRD1-AS1 and lower expression of ZNRD1. To reveal the underlying mechanisms, we then investigated the associations between ZNRD1 eQTLs SNPs in ZNRD1-AS1 and risk of lung cancer in Han Chinese populations. G allele of SNP rs9261204 was significantly associated with an increased risk of lung cancer when compared with A allele (OR: 1.45; 95% CI: 1.19–1.75; P = 1.06 × 10−4). A weaker, but similar effect was also observed in bladder cancer. SNP rs3757328 was also associated with increased risk of lung cancer (OR: 1.34; 95% CI: 1.07–1.67; P = 0.011). Our findings first confirmed the contribution of LncRNA ZNRD1-AS1 to the development of lung cancer in Asian population.