Dysfunction of Nrf2-regulated cellular defence system and JNK activation induced by high dose of fly Ash particles are associated with pulmonary injury in mouse lungs.

The mechanisms of the exposure to fine particulate matter (PM) as a risk factor for pulmonary injury are not fully understood. The transcription factor, NF-E2-related factor 2 (Nrf2), plays a key role in protection lung against PM insult and cancer chemoprevention. In this study, F3-S fly ash particles from a municipal waste incinerator were evaluated as a PM model. We found that F3-S triggered hierarchical oxidative stress responses involving the prolonged activation of the cytoprotective Nrf2 transcriptional program via Keap1 Cys151 modification, and c-Jun NH2-terminal kinase (JNK) phosphorylation at higher doses. In mouse lungs exposed to fly ash particles at a low dose (10-20 mg/kg), Nrf2 signalling was upregulated, while in those exposed to a high fly ash particle dose (40 mg/kg), there was significant activation of JNK, and this correlated with Nrf2 phosphorylation and the downregulation of antioxidant response element (ARE)-driven genes. The JNK inhibitor, SP600125, reversed Nrf2 phosphorylation, and downregulation of detoxifying enzymes. Silencing JNK expression in mouse lungs using adenoviral shRNA inhibited JNK activation and Nrf2 phosphorylation, promoted ARE-driven gene expression, and reduced pulmonary injury. Furthermore, we found that the 452-515 amino acid region within the Neh1 domain of Nrf2 was required for its interaction with P-JNK. We demonstrated that Nrf2 was an important P-JNK target in fly ash-induced pulmonary toxicity. JNK phosphorylated Nrf2, leading to a dysfunction of the Nrf2-mediated defence system.

Effects of exogenous melatonin on the osmotic regulation and antioxidant capacity of Ginkgo biloba seedlings under salt stress.

We investigated the effects of exogenous melatonin on the osmotic regulation and antioxidant capacity of 4-year-old Ginkgo biloba seedlings under salt stress. There were three treatments, with low (50 mmol·L-1), medium (100 mmol·L-1), and high (200 mmol·L-1) NaCl stress. Leaves were sprayed and the soil was watered with melatonin solution (0, 0.02, 0.1, 0.5 mmol·L-1). The results showed that saline stress significantly inhibited the osmoregulation and antioxidant capacities of G. biloba seedlings. Application of exogenous melatonin at appropriate concentrations (0.02, 0.1 mmol·L-1) under salt stress could promote plant growth, reduce the rate of electrolyte leakage, decrease the content of flavonoids and malonic dialdehyde, and enhance peroxidase and superoxide dismutase activities in leaves. High concentration (0.5 mmol·L-1) of exogenous melatonin would aggravate the oxidative and osmotic stresses. The 0.02 and 0.1 mmol·L-1 exogenous melatonin alleviated osmotic stress and oxidative stress in G. biloba seedlings under salt stress, while the 0.02 mmol·L-1 exogenous melatonin treatment had the best effect on NaCl stress alleviation. Ground diameter, branch width, branch length, electrolyte leakage rate, superoxide dismutase activity, and flavonoids content could be used as the key indices for rapid identification of the degree of salt stress in G. biloba seedlings.

NRF2 has a splicing regulatory function involving the survival of motor neuron (SMN) in non-small cell lung cancer.

The nuclear factor erythroid 2-like 2 (NFE2L2; NRF2) signaling pathway is frequently deregulated in human cancers. The critical functions of NRF2, other than its transcriptional activation, in cancers remain largely unknown. Here, we uncovered a previously unrecognized role of NRF2 in the regulation of RNA splicing. Global splicing analysis revealed that NRF2 knockdown in non-small cell lung cancer (NSCLC) A549 cells altered 839 alternative splicing (AS) events in 485 genes. Mechanistic studies demonstrated that NRF2 transcriptionally regulated SMN mRNA expression by binding to two antioxidant response elements in the SMN1 promoter. Post-transcriptionally, NRF2 was physically associated with the SMN protein. The Neh2 domain of NRF2, as well as the YG box and the region encoded by exon 7 of SMN, were required for their interaction. NRF2 formed a complex with SMN and Gemin2 in nuclear gems and Cajal bodies. Furthermore, the NRF2-SMN interaction regulated RNA splicing by expressing SMN in NRF2-knockout HeLa cells, reverting some of the altered RNA splicing. Moreover, SMN overexpression was significantly associated with alterations in the NRF2 pathway in patients with lung squamous cell carcinoma from The Cancer Genome Atlas. Taken together, our findings suggest a novel therapeutic strategy for cancers involving an aberrant NRF2 pathway.

Survey and analysis of willingness to use mobile medical services and influencing factors of TB patients treated at home.

INTRODUCTION: The objective of this study was to investigate the willingness of patients with tuberculosis (TB) to use mobile medical services (mHealth) and its influencing factors, so as to provide theoretical guidance for optimizing the TB mobile medical platform and improve the willingness of patients to use mHealth. METHODOLOGY: In this cross-sectional study, convenience sampling method was used to investigate patients with TB from the outpatient clinics of two TB specialized hospitals (Beijing Thoracic Tumor and Tuberculosis Hospital and Tuberculosis Prevention and Treatment Hospital of Shaanxi Province) from January to June 2021 using a self-designed questionnaire. RESULTS: Out of 231 patients, only 90 (38.96%) were aware of mHealth services, and 63 (27.27%) had used mHealth services. Among the 63 patients who had used mHealth services, the proportion of mobile medical forms based on WeChat platform was 74.89%. Patients' willingness to use mHealth was scored (11.49 ± 2.53). Univariate analysis showed that the scores of patients' willingness to use mHealth differed by gender and the different ways of affording healthcare (p < 0.05). Regression analysis showed that the influencing factors of willingness to use mHealth in patients with TB included attitude towards use (0.750), health beliefs (0.091) and social impact (0.169) (adjusted R2 = 0.781, p < 0.001). CONCLUSIONS: Patients' awareness of the advantages of the new medical model needs to be improved. Optimized design can improve the willingness of patients to use mHealth services and improve the role of mHealth in patient management.

Transcriptome analysis of potential candidate genes and molecular pathways in colitis-associated colorectal cancer of Mkp-1-deficient mice.

BACKGROUND: The nuclear phosphatase mitogen-activate protein kinase phosphatase-1 (MKP-1) is a key negative regulator of the innate immune response through the regulation of the biosynthesis of proinflammatory cytokines. In colorectal cancer (CRC), which is induced mainly by chronic inflammation, Mkp-1 overexpression was found in addition to disturbances in Mkp-1 functions, which may play a role in cancer development in different types of tumors. However, the potential molecular mechanisms by which Mkp-1 influences CRC development is not clear. Here, we performed global gene expression profiling of Mkp-1 KO mice using RNA sequencing (RNA-seq) to explore the role of Mkp-1 in CRC progression using transcriptome analysis. METHODS: Azoxymethane/dextran sodium sulfate (AOM/DSS) mouse models were used to examine the most dramatic molecular and signaling changes that occur during different phases of CRC development in wild-type mice and Mkp-1 KO mice. Comprehensive bioinformatics analyses were used to elucidate the molecular processes regulated by Mkp-1. Differentially expressed genes (DEGs) were identified and functionally analyzed by Gene Ontology (GO), Kyoto Enrichment of Genes and Genomes (KEGG). Then, protein-protein interaction (PPI) network analysis was conducted using the STRING database and Cytoscape software. RESULTS: Persistent DEGs were different in adenoma and carcinoma stage (238 & 251, respectively) and in WT and MKp-1 KO mice (221& 196, respectively). Mkp-1 KO modulated key molecular processes typically activated in cancer, in particular, cell adhesion, ion transport, extracellular matrix organization, response to drug, response to hypoxia, and response to toxic substance. It was obvious that these pathways are closely associated with cancer development and metastasis. From the PPI network analyses, nine hub genes associated with CRC were identified. CONCLUSION: These findings suggest that MKp-1 and its hub genes may play a critical role in cancer development, prognosis, and determining treatment outcomes. We provide clues to build a potential link between Mkp-1 and colitis-associated tumorigenesis and identify areas requiring further investigation.

Integrated data analysis reveals significant associations of KEAP1 mutations with DNA methylation alterations in lung adenocarcinomas.

KEAP1 regulates the cytoprotection induced by NRF2 and has been reported to be a candidate tumor suppressor. Recent evidence has shown that mutations in several driver genes cause aberrant DNA methylation patterns, a hallmark of cancer. However, the correlation between KEAP1 mutations and DNA methylation in lung cancer has still not been investigated. In this study, we systematically carried out an integrated multi-omics analysis to explore the correlation between KEAP1 mutations and DNA methylation and its effect on gene expression in lung adenocarcinoma (LUAD). We found that most of the DNA aberrations associated with KEAP1 mutations in LAUD were hypomethylation. Surprisingly, we found several NRF2-regulated genes among the genes that showed differential DNA methylation. Moreover, we identified an 8-gene signature with altered DNA methylation pattern and elevated gene expression levels in LUAD patients with mutated KEAP1, and evaluated the prognostic value of this signature in various clinical datasets. These results establish that KEAP1 mutations are associated with DNA methylation changes capable of shaping regulatory network functions. Combining both epigenomic and transcriptomic changes along with KEAP1 mutations may provide a better understanding of the molecular mechanisms associated with the progression of lung cancer and may help to provide better therapeutic approaches.

c-Jun NH2 -Terminal Protein Kinase Phosphorylates the Nrf2-ECH Homology 6 Domain of Nuclear Factor Erythroid 2-Related Factor 2 and Downregulates Cytoprotective Genes in Acetaminophen-Induced Liver Injury in Mice.

BACKGROUND AND AIMS: Acetaminophen (APAP) overdose induces severe liver injury and hepatic failure. While the activation of c-Jun NH2 -terminal kinase (JNK) has been implicated as a mechanism in APAP-induced liver injury, the hepatic defense system controlled by nuclear factor erythroid 2-related factor 2 (Nrf2) plays a central role in the mitigation of APAP toxicity. However, the link between the two signaling pathways in APAP-induced liver injury (AILI) remains unclear. APPROACH AND RESULTS: In this study, we demonstrated that the activation of JNK in mouse liver following exposure to APAP was correlated with the phosphorylation of Nrf2 and down-regulation of the antioxidant response element (ARE)-driven genes, NAD(P)H:quinone dehydrogenase 1, glutathione S-transferase α3, glutathione S-transferase M1, glutathione S-transferase M5, and aldo-keto reductase 1C. The JNK inhibitor, SP600125, or knockdown of JNK by infection of adenovirus expressing JNK small interfering RNA, ameliorated the APAP induced liver toxicity, and inhibited the phosphorylation of Nrf2 and down-regulation of detoxifying enzymes by stabilizing the transcription factor. Mechanistically, JNK antagonized Nrf2- and ARE-driven gene expression in a Kelch-like ECH-associated protein 1-independent manner. Biochemical analysis revealed that phosphorylated JNK (P-JNK) directly interacted with the Nrf2-ECH homology (Neh) 1 domain of Nrf2 and phosphorylated the serine-aspartate-serine motif 1 (SDS1) region in the Neh6 domain of Nrf2. CONCLUSIONS: Mass spectrometric analysis identified serine 335 in the SDS1 region of mNrf2 as the major phosphorylation site for modulation of Nrf2 ubiquitylation by P-JNK. This study demonstrates that Nrf2 is a target of P-JNK in AILI. Our finding may provide a strategy for the treatment of AILI.

Transcriptomic profiling identifies a critical role of Nrf2 in regulating the inflammatory response to fly ash particles in mouse lung.

Exposure to combustion-derived nanoparticles is recognized as a major health hazard, but the molecular responses are still insufficiently described. The transcription factor erythroid 2-related factor 2 (Nrf2, also known as NFE2L2) is a master regulator of the pulmonary defense system against insults by particulate matter. However, its downstream molecular processes are not fully characterized. In the current study, BALB/c wild-type (WT) and Nrf2-/- mice were exposed by intranasal administration to fly ash particles (F3-S; 20 mg/kg BW), which were collected from a municipal waste incinerator in China, for three consecutive days. Using a comparative transcriptomics approach, the pulmonary global gene expression profiles to F3-S exposure were characterized for both genotypes. The preponderance of the differentially-expressed genes (DEGs) in WT mice induced by the fly ash particles, was related to inflammation. Functional enrichment and molecular pathway mapping of the DEGs specific to Nrf2-/- mice exposed to the particles revealed that all of the top 10 perturbed molecular pathways were associated with the inflammatory response. Our study identified a transcriptional signature related to the initial pulmonary injury in mouse upon fly ash exposure, and suggests an anti-inflammatory role of Nrf2 in protecting the lung against such exposure.

Comparative transcriptome analysis reveals Dusp1 as a critical regulator of inflammatory response to fly ash particle exposure in mouse.

Exposure to outdoor concentrations of fine particulate matter (PM2.5) is a leading global health concern. Waste incineration emission has been recognized as a potential major contributor of ambient PM2.5. Respiratory inflammation is a central feature induced by PM2.5 exposure by inhalation. However, the molecular mechanisms are not fully understood. Dual-specificity phosphatase 1 (Dusp1) plays an instrumental role in the regulation of airway inflammation. In this study, fly ash particles (20 mg/kg BW) collected from a municipal waste incinerator in China were given to BALB/c wild-type (WT) and Dusp1-/- mice by intranasal administration daily for three consecutive days. While these particles induced mild inflammation in both genotypes, a significantly higher level of serum interleukin-6 (665 pg/ml) was measured in Dusp1-/- mice challenged with fly ash particles than in their WT counterparts. Genome-wide transcriptome profiling of pulmonary coding genes in response to the exposure were performed in both genotypes by RNA sequencing. We identified 487 differentially-expressed genes (DEGs) in fly ash-challenged Dusp1-/- mice versus their WT counterparts with a log2fold-change >1.5 and p < 0.05. Functional enrichment and molecular pathway mapping of the DEGs specific to Dusp1-/- mice exposed to the particles revealed that the top 10 perturbed molecular pathways were associated with the immune response. Our study demonstrates the anti-inflammatory role of Dusp1 in protecting the lung against insults by fly ash particles, suggesting that Dusp1 might be a therapeutic target for the treatment of PM2.5-induced respiratory diseases.

Interplay of MKP-1 and Nrf2 drives tumor growth and drug resistance in non-small cell lung cancer.

Alterations in KEAP1/ NF-E2 p45-related factor 2 (NFE2L2/Nrf2) signaling pathway have been reported in 23% lung adenocarcinoma patients, suggesting that deregulation of the pathway is a major cancer driver. Here we report that mitogen-activated protein (MAP) kinase phosphatase 1 (MKP-1) drives tumor growth and drug resistance by up regulating transcription factor Nrf2. In non-small cell lung cancer (NSCLC) cells and xenografts, MKP-1 knockdown triggered the down-regulation of the metabolic enzymes and cytoprotective proteins, which are the target genes of Nrf2. Consequently, the cell growth was markedly inhibited with decrease of tumor metabolisms and GSH contents. Moreover, MKP-1 silencing sensitized NSCLC cells to cisplatin treatment. Mechanistically, MKP-1 inhibited the ubiquitylation of Nrf2 via a direct interaction with the transcription factor. Nrf2 was hence stabilized and its transcriptional program was activated. Notably, Nrf2 elevated MKP-1 expression at transcriptional level. In human lung adenoma tumor samples, high levels of expression of MKP-1, Nrf2, and its target gene heme oxygenase 1 were closely correlated. Thus, MKP-1 and Nrf2 form a forward feedback loop in lung cancer cells, which stabilizing and activating Nrf2 to promote anabolic metabolism and GSH biosynthesis. This study uncovers a novel role of MKP-1 in the malignant evolution of cancers.

Systematic Identification of Multi Omics-based Biomarkers in KEAP1 Mutated TCGA Lung Adenocarcinoma.

Mutations in KEAP1 and/or NRF2 genes have been identified across many cancers and the dysregulation of the NRF2 pathway due to these mutations leads to drug and radioresistance in several cancers. Identification of biomarkers associated with these mutations allows the researchers and clinicians to identify the personalized medicine and quicker diagnosis. In this current study, we carried out an integrated, multi-omics, multi-database analysis of exome, transcriptomics data's of KEAP1 mutated TCGA- Lung adenocarcinoma (LUAD) patients against non-mutated counterparts. Finally, we discovered the gene signature associated with KEAP1 mutations, prognostic genes which were highly correlated with the upregulation of the NRF2 pathway in the KEAP1 mutated LUAD patients. Our finding might be useful to identify the early diagnosis of KEAP1 mutated LUAD patients.

Genome-wide global identification of NRF2 binding sites in A549 non-small cell lung cancer cells by ChIP-Seq reveals NRF2 regulation of genes involved in focal adhesion pathways.

Nuclear factor erythroid-derived-2-like 2(NRF2) regulates its downstream genes through binding with antioxidant responsive elements in their promoter regions. Hyperactivation of NRF2 results in oncogenesis and drug resistance in various cancers including non-small cell lung cancer (NSCLC). However, identification of the genes and pathways regulated by NRF2 in NSCLC warrants further investigation. We investigated the global NRF2 genomic binding sites using the high-throughput ChIP-Seq technique in KEAP1 (Kelch-like ECH-associated protein 1)-mutated A549 (NSCLC) cells. We next carried out an integrated analysis of the ChIP-Seq data with transcriptomic data from A549 cells with NRF2-knockdown and RNA-Seq data from TCGA patients with altered KEAP1 to identify downstream and clinically-correlated genes respectively. Furthermore, we applied transcription factor enrichment analysis, generated a protein-protein interaction network, and used kinase enrichment analysis. Moreover, functional annotation of NRF2 binding sites using DAVID v7 identified the genes involved in focal adhesion. Putative focal adhesion genes regulated by NRF2 were validated using qRT-PCR. Further, we selected one novel conserved focal adhesion gene regulated by NRF2-LAMC1 (laminin subunit gamma 1) and validated it using a reporter assay. Overall, the identification of NRF2 target genes paves the way for identifying the molecular mechanism of NRF2 signaling in NSCLC development and therapy. Moreover, our data highlight the complexity of the pathways regulated by NRF2 in lung tumorigenesis.

Synthetic Imine Resveratrol Analog 2-Methoxyl-3,6-Dihydroxyl-IRA Ameliorates Colitis by Activating Protective Nrf2 Pathway and Inhibiting NLRP3 Expression.

Resveratrol (RSV) is a naturally occurring polyphenol that exhibits pleiotropic health benefits, including anticolitis and colon cancer-protective activity. Recently, we identified the novel imine RSV analog (IRA), 2-methoxyl-3,6-dihydroxyl-IRA 3,4,5,4-tetramethoxystilbene (C33), as a putative activator of nuclear factor erythroid 2-related factor 2 (Nrf2). The present study was designed to evaluate the ability of C33 to activate the Nrf2 signaling pathway and its anticolitis effect in comparison to RSV. The anticolitis action of C33 was assessed in a mouse model of colitis induced by dextran sulfate sodium (DSS). The effect of C33 on the Nrf2 signaling pathway was examined in vitro and in vivo. Compared to RSV, C33 triggered a more dramatic increase in the expression of genes downstream of Nrf2 in LS174T cells as well as in the small intestine and colon of wild-type (WT) mice. Correlated with its superior ability to activate the cytoprotective Nrf2 pathway, C33 was significantly better in ameliorating DSS-induced colitis by improving the inflammation score, as well as downregulating the markers of inflammation in WT mice. Moreover, induction of the NOD-like receptors family pyrin domain containing 3 (NLRP3) inflammasome by colitis was also significantly inhibited by the IRA. Nrf2 knockout completely abolished the effects of C33, indicating that Nrf2 is the important mechanistic target of C33 in vivo. In conclusion, the novel IRA, C33, has stronger anticolitis effects than RSV. Further studies are warranted to evaluate C33 as a potential therapeutic agent for inflammatory bowel disease and cancer chemoprevention.

"NRF2 addiction" in lung cancer cells and its impact on cancer therapy.

Nuclear factor erythroid 2-like factor 2 (NRF2) is a master regulator of the antioxidant enzymes and the detoxification proteins that play major roles in redox homeostasis. Although it plays a protective role against tumorigenesis, emerging evidence has shown that the NRF2 pathway is frequently altered in different types of cancer, including lung cancer. NRF2 activation influences many of the hallmarks of cancer and their signaling pathways, mainly apoptosis, proliferation, angiogenesis, metastasis, and metabolic reprogramming to establish cellular metabolic processes leading to "NRF2 addiction" in lung cancer cells. Intriguingly, constitutive activation of NRF2 promotes cancer development as well as resistance to chemotherapy and radiotherapy, and these malignant phenotypes lead to a poor prognosis in lung cancer patients. Therefore, targeted inhibition of the NRF2 together with traditional chemotherapy, radiotherapy, and immunotherapy, may be a promising approach to improving the survival rates of the NRF2-addicted lung cancer cases. Here we summarize the recent advances in NRF2-addicted lung cancer.

Enhancement of Galloylation Efficacy of Stigmasterol and ß-Sitosterol Followed by Evaluation of Cholesterol-Reducing Activity.

In this study, incorporation of gallic acid into typical phytosterols (ß-sitosterol and stigmasterol) through Steglich esterification was optimized employing the protection and deprotection strategy. A novel mechanism leading to side esterification was discovered. Complication of the phenolic hydroxyl groups and side reactions were successfully reduced under the optimized conditions. The structural identity and purity of galloyl stigmasterol and galloyl ß-sitosterol were confirmed by NMR, FT-IR, and HPLC-MS. Evaluation of galloyl ß-sitosterol and galloyl stigmasterol revealed their excellent antioxidant and cholesterol-reducing activities. Significant enhancement of cholesterol-reducing activity by galloylation was unveiled especially for ß-sitosterol. Galloyl ß-sitosterol had slightly better antioxidant activity at ambient temperature and better cholesterol-reducing activity. Molecular modeling suggested that a subtle difference of galloyl ß-sitosterol and galloyl stigmasterol in activities could be attributed to variation of molecular rigidity and conformation. The excellent properties of galloyl ß-sitosterol and galloyl stigmasterol suggested their great potential application in the food industry.

Mkp-1 is required for chemopreventive activity of butylated hydroxyanisole and resveratrol against colitis-associated colon tumorigenesis.

Many dietary compounds show promising protective activity against colon cancer by activating nuclear factor-erythroid 2 related factor 2 (Nrf2). Recently, we reported that mitogen-activated protein kinase phosphatase 1 (Mkp-1) exhibits crosstalk with the Nrf2 signaling pathway, protecting against intestinal inflammation. Here, we present evidence that Mkp-1 is required for the chemopreventive action of the Nrf2 activators butylated hydroxyanisole (BHA) and resveratrol (RSV). In an azoxymethane/dextran sulfate sodium model of colitis-associated tumorigenesis, Mkp-1-/- mice exhibited a phenotype similar to Nrf2-/- mice with significantly more tumors than WT mice. Tumors from Mkp-1-/- mice exhibited higher levels of macrophage infiltration than those from WT mice. This was accompanied by increased expression of nitrotyrosine and p53BP1, markers of oxidative stress and DNA damage, respectively. Moreover, dietary suppression of tumorigenesis using BHA (0.5%) or RSV (300 ppm) supplementation was achieved in WT but not in Mkp-1-/- mice. In adenomas from WT mice, the expression of Mkp-1 was markedly lower than in adjacent normal tissue, concomitant with the down-regulation of Nrf2 and its target genes. Our data revealed that Mkp-1 is required in the protective role of Nrf2 signaling against colitis-associated tumorigenesis.

AKR1B10 expression predicts response of gastric cancer to neoadjuvant chemotherapy.

Effective methods for predicting tumor response to preoperative chemotherapy are required. Aldo-ketoreductase family 1 member B10 (AKR1B10) is predominantly expressed in the gastrointestinal tract and serves an important function in cancer development and progression. The present study investigated whether AKR1B10 expression may predict the therapeutic response of locally advanced gastric cancer. A total of 53 patients with gastric cancer underwent neoadjuvant chemotherapy followed by surgery between January 2006 and December 2015. The protein expression level of AKR1B10 was determined in paraffin-embedded biopsy specimens using immunohistochemistry. Western blotting confirmed that the AKR1B10 protein is primarily localized to the cytoplasm. χ2 and Fisher's exact tests were used to determine the association of AKR1B10 with a number of clinic opathological features. Univariate and multivariate analyses were used to identify the prognostic factors. Survival rates were compared using Kaplan-Meier curves with a log-rank test. The positive rate of AKR1B10 protein expression was 58.5%, whereas 41.5% samples exhibited negative expression. The frequency of AKR1B10-positive gastric cancer samples was increased in patients with lymph node metastasis and decreased in those exhibiting tumor regression. The 5-years overall survival rate for the AKR1B10-positive group was significantly poorer than that for the AKR1B10-negative group. AKR1B10 expression was associated with lymph node metastasis and a poorer prognosis, along with a poor response to neoadjuvant chemotherapy suggesting that AKR1B10 may be a potential predictor for the therapeutic response of locally-advanced gastric cancer.

Using Nrf2/antioxidant response element-dependent signaling to assess the toxicity potential of fly ash particles.

Epidemiological studies have demonstrated an association between ambient particulate pollution and adverse health effects in humans. The antioxidant-responsive element (ARE) cytoprotective system mediated by the transcription factor NF-E2 p45-related factor 2 (Nrf2) serves as a primary defense against the oxidative stress triggered by particulate matter. In this study, using a cell-based ARE-reporter assay, the fine fractions of the fly ash collected from the municipal solid waste incinerators at four cities in China were examined for their ability to activate Nrf2/ARE signaling. We found that, at a non-lethal dose, all the fly ash samples were able to activate the ARE-reporter gene in a dose- and redox-dependent manner, and this was correlated with their cytotoxicity and their ability to induce DNA damage. Study of the kinetics revealed that fly ash particles elicited a prolonged activation of the ARE-reporter activity. Upon exposure to the particles, the ARE-luciferase activity significantly increased in 2 h, reached a peak at 24 h, and remained high level at 72 h. This was in contrast to the transient activation of the ARE-reporter gene triggered by the Nrf2 activators tert-butylhydroquinone and sulforaphane, while ARE-luciferase activity dropped to the basal level at 72 h from the peak at 24 h. These results demonstrate the robustness of using cell-based ARE-reporter assays to evaluate the oxidative potential of fly ash. Our novel findings suggest that the sustained activation of the Nrf2/ARE signaling pathway induced by fly ash particles perturbs cellular redox homeostasis, which in turn contributes to toxicity.

Mkp-1 cross-talks with Nrf2/Ho-1 pathway protecting against intestinal inflammation.

Inflammatory bowel disease (IBD) is associated with intense oxidative stress, contributes to colonic damage and tumorigenesis. Mitogen-activated protein kinase phosphatase 1 (Mkp-1) is an essential negative regulator of the innate immune response. However, its role in colitis, and its association with the nuclear factor-erythroid 2 related factor 2 (Nrf2), a master regulator of cytoprotection program against oxidative stress, in inflammatory response, is elusive. In this study, we found that increased expression of Mkp-1, Nrf2, and heme oxygenase 1 (Ho-1) was correlated in colonic tissues in patients with ulcerative colitis and Crohn's disease, as well as wild-type mice with colitis induced by dextran sodium sulfate (DSS). Mkp-1-/- mice were more susceptible to DSS-induced colitis with more severe crypt injury and inflammation. Mechanistically, directly interacting with the DIDLID motif of Nrf2, Mkp-1 increased Nrf2 stability and positively regulated the constitutive and lipopolysaccharide (LPS)-inducible Nrf2/Ho-1 expression. Conversely, upon exposure to LPS, Nrf2 activated Mkp-1 transcription through the antioxidant response elements in the promoter of Mkp-1. Our results revealed a novel link between Mkp-1 and Nrf2 signaling pathways in protecting against colonic inflammation. Mkp-1 might be a therapeutic target for IBD.