Wei Zheng

Nanjing University, Nan-ching, Jiangsu Sheng, China

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Publications (15)56.37 Total impact

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    ABSTRACT: Epigallocatechin-3-gallate (EGCG) exerts anti-inflammatory properties on immune cells and binds to CD4 molecules. However, the effects of EGCG on CD4(+) T cells remain largely unknown. Here, we found that EGCG enhanced IFN-γ-induced signal transducer and activator of transcription 1 (STAT1) activation in primary CD4(+) T cells from C57BL/6 mice and in a human leukemic CD4(+) T-cell line of Hut 78 cells, while it inhibited the classical pathway of IFN-γ signaling including activating phosphorylations of Janus kinase (JAK) 1, JAK2 and STAT3, forming interferon-γ activated sequence (GAS)-binding STAT1 homodimers, and producing pro-inflammatory chemokine (C-X-C motif) ligand 9 (CXCL9). CD4 blockade did not suppress the increase in IFN-γ-induced STAT1 activation in CD4(+) T cells by EGCG. Furthermore, activation of Src kinase was also triggered by IFN-γ plus EGCG in both Hut 78 and primary CD4(+) T cells. Interestingly, EGCG promoted apoptosis of CD4(+) T cells treated with IFN-γ. The increases in STAT1 activation and apoptosis induced by EGCG in IFN-γ-activated CD4(+) T cells were almost completely abolished by a selective Src family kinase inhibitor, SU6656. Moreover, EGCG alleviates CD4(+) CD45RB(hi) CD25(-) T cell transfer induced colitis with less accumulation of CD4(+) T cells in the colon. In conclusion, the present study reports an alternative activation of STAT1 via Src by EGCG in IFN-γ-activated CD4(+) T cells, which promotes the apoptosis of IFN-γ-activated CD4(+) T cells and contributes to the improvement of T cell-mediated colitis. Our findings suggest a novel role of EGCG in regulating IFN-γ signaling and controlling inflammation.
    International immunopharmacology. 09/2014;
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    ABSTRACT: Triptolide (TP) is a biologically active diterpene triepoxide from the Chinese herb Tripterygium wilfordii Hook f. Here, we identify and explore TAB1 as the binding target of TP in macrophages by using a comprehensive approach combining pull-down assays, in vitro assessments, and pharmaceutical and biological evaluation. We discover that TP inhibits TAK1 kinase activity by interfering with the formation of the TAK1-TAB1 complex, and the binding affinity of TP to TAB1 correlates highly with the inhibitory activity of TP against MAPK pathway activation in macrophages. We also find that the amino acid sequence between positions 373 and 502 of TAB1 is required for TP interaction. Our results suggest that TP could be a selective small-molecule inhibitor of the TAK1-TAB1 complex and that TAB1 could be a potential therapeutic target in inflammatory disease.
    Chemistry & biology 01/2014; · 6.52 Impact Factor
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    ABSTRACT: Post-translational regulation plays a critical role in the control of cell growth and proliferation. The phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ) is the most important post-translational modification. The function of PPARγ phosphorylation has been studied extensively in the past. However, the relationship between phosphorylated PPARγ1 and tumors remains unclear. Here we investigated the role of PPARγ1 phosphorylation in human fibrosarcoma HT1080 cell line. Using the nonphosphorylation (Ser84 to alanine, S84A) and phosphorylation (Ser84 to aspartic acid, S84D) mutant of PPARγ1, the results suggested that phosphorylation attenuated PPARγ1 transcriptional activity. Meanwhile, we demonstrated that phosphorylated PPARγ1 promoted HT1080 cell proliferation and this effect was dependent on the regulation of cell cycle arrest. The mRNA levels of cyclin-dependent kinase inhibitor (CKI) p21(Waf1/Cip1) and p27(Kip1) descended in PPARγ1(S84D) stable HT1080 cell, whereas the expression of p18(INK4C) was not changed. Moreover, compared to the PPARγ1(S84A), PPARγ1(S84D) up-regulated the expression levels of cyclin D1 and cyclin A. Finally, PPARγ1 phosphorylation reduced sensitivity to agonist rosiglitazone and increased resistance to anticancer drug 5-fluorouracil (5-FU) in HT1080 cell. Our findings establish PPARγ1 phosphorylation as a critical event in human fibrosarcoma growth. These findings raise the possibility that chemical compounds that prevent the phosphorylation of PPARγ1 could act as anticancer drugs.
    Experimental Cell Research 01/2014; · 3.56 Impact Factor
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    ABSTRACT: In contrast to T cell priming in the periphery, therapeutic strategies targeting the initiation step of T cell trafficking into the central nervous system (CNS) have not been extensively investigated. In this study, the effect of NSC-87877, a potent SHP-2 inhibitor, on experimental autoimmune encephalomyelitis (EAE) and the unique mechanism were elucidated. C57BL/6 mice were immunized with MOG35-55 and monitored for clinical severity of disease and histopathologic features in the CNS. Levels of cytokines in serum were measured by ELISA. Effects of NSC-87877 on expressions of chemokines and cytokines in the CNS were determined by quantitative PCR. NSC-87877-treated mice developed conventional TH 1 and TH 17 responses but were highly resistant to the induction of EAE. Treatment with NSC-87877 resulted in decreased CNS accumulation of lymphocytes and increased functional expression of the chemokine receptor CXCR7 on CD8(+) T cells. Moreover, adoptive transfer of T cells from 2D2-transgenic mice reconstituted EAE susceptibility in NSC-87877-treated mice, indicating that NSC-87877 only targets the initial migration of pioneer T cells. Furthermore, T cell-conditional SHP-2-deficient mice treated with NSC-87877 were no longer resistant to EAE, suggesting that inhibition of SHP-2 contributes to the amelioration of disease by NSC-87877. NSC-87877 almost completely abolished the development of EAE by blocking the initial infiltration of pioneer CD8(+) T cells into the uninflamed CNS. These results reveal a critical role for SHP-2 in regulating EAE pathogenesis and support NSC-87877 as a potential lead compound for the treatment of relapsing-remitting multiple sclerosis.
    British Journal of Pharmacology 12/2013; · 5.07 Impact Factor
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    ABSTRACT: In situ chemical oxidation (ISCO) can be an effective technology for the remediation of soil and groundwater polluted by organic and inorganic contaminants. This study investigated the oxidation of arsenic(III) (As(III)) and diuron using ferrous activated persulfate-based ISCO. The results indicated that Fe(II)/persulfate oxidation could be an effective method to oxidize As(III) and diuron. Effects of pH, S2O8(2-) and Fe(II) amounts on the destruction of As(III) and diuron were examined in batch experiments. Acidic conditions favored the removal of As(III) and diuron. Four chelating agents, citric acid (CA), Na2S2O3, diethylene triamine pentaacetic acid (DTPA) and ethylene diamine tetraacetic acid disodium (EDTA-Na2) were used in attempt to maintain the quantity of ferrous ion in solution. In our experiments, CA and Na2S2O3 were found to be more effective than DTPA and EDTA-Na2. Our results also revealed a widely practical prospect of inorganic chelating agent Na2S2O3. Hydroxyl and sulfate radical were determined to play key roles in the oxidation process by using ethanol and tertiary butanol as molecular probes. Oxidation of As(III) yielded As(V) via the electron-transfer reaction. In the oxidation process of diuron, a stepwise nucleophilic substitution of chlorine by hydroxyl and a stepwise oxidation process of the methyl on the dimethylurea group by hydroxyl and sulfate radical were proposed.
    Journal of hazardous materials 10/2013; · 4.14 Impact Factor
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    ABSTRACT: Extracellular signal-regulated kinase (ERK) belongs to the mitogen-activated protein kinases (MAPK) superfamily. Aberrant upregulation and activation of ERK cascades may often lead to tumor cell development. However, how ERK is involved in tumor progression is yet to be defined. In current study, we described that ERK undergoes S-nitrosylation by nitric oxide (NO). ERK S-nitrosylation inhibits its phosphorylation and triggers apoptotic program as verified by massive apoptosis in fluorescence staining. The proapoptotic effect of NO induced S-nitrosylation is reversed by NO scavenger Haemoglobin (HB). Furthermore, an S-nitrosylation dead ERK mutant C183A also demolishes the proapoptotic potential of NO and favors cell survival. Therefore, Cys(183) might be a potential S-nitrosylation site in ERK. In addition, S-nitrosylation is a general phenomenon that regulates ERK activity. These findings identify a novel link between NO-mediated S-nitrosylation and ERK regulation, which provide critical insights into the control of apoptosis and tumor development.
    Scientific Reports 05/2013; 3:1814. · 5.08 Impact Factor
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    ABSTRACT: Aim: Malignant melanoma is well known for abundant ROS (reactive oxygen species) that exist in the primary tumor environment. Within this microenvironment, TAMs (tumor-associated macrophages) play substantial roles in multiple steps of tumor development in terms of tumor growth, invasion and metastasis. We therefore aimed to determine whether this high-level ROS in primary melanoma is capable to promote tumor invasiveness by influencing TAM properties. Moreover, we wanted to further investigate probable underlying mechanisms. Results: We characterized malignant melanoma TAMs as heterogeneous phenotype which possesses both M1 and M2 markers. We also revealed a role for high-level intracellular ROS in enhancing pro-invasion signature of TAMs by strongly increasing their TNF-α (tumor necrosis factor α) secretion, which is possibly attributed to ROS-enhanced PPARγ (peroxisome proliferator-activated receptor γ) translocation mediated by MEK-1 (MAPK/ERK kinase 1). Innovation: This is the first study demonstrating that high levels of ROS in primary melanoma environment can influence TAM behaviors. Furthermore, we are also the first to indentify that nucleus-to-cytoplasm translocation of PPARγ is significantly up-regulated by ROS and is responsible for pro-invasiveness capacity of melanoma TAMs. Conclusion: Taken together, our data describe how high level of ROS plays a critical role in enhancing the pro-invasion characteristic of TAMs in malignant melanoma.
    Antioxidants & Redox Signaling 02/2013; · 8.20 Impact Factor
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    ABSTRACT: Hepatocarcinoma cancer (HCC), one of the most malignant cancers, occurs significantly more often in men than in women; however little is known about its underlying molecular mechanisms. Here we identify that 17β-estradiol (E2) could suppress tumor growth via regulating the polarization of macrophages. We show that E2 re-administration reduces tumor growth in orthotopic and xenotopic mice HCC models. E2 functions as a suppressor for macrophage alternative activation and tumor progression by keeping estrogen receptor beta (ERβ) away from interacting with ATP synthase-coupling factor 6 (ATP5J), a part ATP synthetase, thus inhibiting JAK1-STAT6 signaling pathway. These studies introduce a novel mechanism for suppressing male-predominant HCC.
    Journal of Biological Chemistry 08/2012; · 4.65 Impact Factor
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    ABSTRACT: A small molecule, 15b-β-hydroxy-5-N-acetylardeemin (IFB07188), was previously isolated from the fungi Aspergillus terreus. However, the toxicological features of this natural product have never been investigated. In present study, we described the anticancer activities of IFB07188. We found that IFB07188 can decrease the viability and invasive potency of multiple cancer cell lines. Further mechanistic investigation demonstrates that cell cycles are arrested at G2/M phase and the arrest is induced by deregulated cell cycle proteins. A concomitant flow cytometric analysis also shows that IFB07188 can trigger massive apoptosis in a dose-dependent manner. The proapoptotic effect of IFB07188-treated cancer cells is characterized by depolarization of mitochondria membrane potential (Δψ(m)) and positive Hochest staining. Finally, results from invasion assay suggest that IFB07188 can suppress tumor cell invasion independent of apoptosis. Collectively, these data establish that IFB07188 can effectively inhibit cancer cell growth and invasiveness, prompting its potential use in cancer chemotherapy.
    Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 06/2012; 66(7):512-8. · 2.24 Impact Factor
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    ABSTRACT: Triptolide, a diterpene triepoxide, is one of the major components of most functional extracts of Tripterygium wilfordii Hook f, which is known to have various biological effects, including immunosuppressive, anti-inflammatory and anti-tumor functions. We studied the inhibitory effect of triptolide on endotoxemia (ETM)-induced oxidative stress, which was induced in C57BL/6 mice by lipopolysaccharide (LPS) and D-galactosamine (D-GalN). Pretreatment with triptolide decreased the reactive oxygen species (ROS) levels, mortality rate and liver injury after LPS/D-GalN injection. We utilized comprehensive proteomics to identify alterations in liver protein expression during pretreatment with triptolide or N-acetylcysteine (NAC) after LPS/D-GalN injection, 44 proteins were found to be related to oxidative stress, mitochondria, metabolism and signal transduction, and 23 proteins of them seemed to be significantly up- or down-regulated. Furthermore, both triptolide and NAC inhibited activation of c-jun NH2-terminal kinases (JNK) and mitogen-activated protein kinase p38 (p38), phosphorylation of inhibitor of nuclear factor-kappa B (IκB) and activation of nuclear factor-κB (NF-κB). These results demonstrated that triptolide inhibited the activation of JNK and p38 by decreasing ROS levels, which in turn inhibited the hepatic injury. In addition, we set and validated the phosphorylation model of extracellular signal-regulated kinase (ERK) and proposed that triptolide probably induced ERK phosphorylation through inhibiting its dephosphorylation rates. These results showed that triptolide can effectively reduce the oxidative stress and partially rescue the damage in the liver induced by LPS/D-GalN.
    Journal of Cellular Biochemistry 11/2011; 113(3):1022-33. · 3.06 Impact Factor
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    ABSTRACT: Erlotinib is a potent inhibitor of epidermal growth factor receptor tyrosine kinase and has been demonstrated to treat advanced or metastatic non-small cell lung cancer to prolong survival after failure of first-line or second-line chemotherapy. However, little is known about its effects on immune system. In the present study, we aimed to investigate the immunosuppressive activity of erlotinib on T lymphocytes both in vitro and in vivo, and further explore its potential molecular mechanism. Erlotinib exerted a significant inhibition on the T cell proliferation and activation induced by concanavalin A, anti-CD3 plus anti-CD28, staphylococcal enterotoxin B or phorbol myristate acetate respectively in a concentration-dependent manner and it also inhibited the secretion of the proinflammatory cytokines such as IL-2 and IFN-γ of activated T cells. Further study showed that erlotinib caused G0/G1 arrest and suppressed the phosphorylations of c-Raf, ERK and Akt in activated T cells. Moreover, erlotinib significantly ameliorated picryl chloride-induced ear contact dermatitis in a dose-dependent manner in vivo. In summary, these findings suggest that erlotinib may cause the impairment of T-cell-mediated immune response both in vitro and in vivo through inhibiting T cell proliferation and activation, which is closely associated with its potent down-regulation of the c-Raf/ERK cascade and Akt signaling pathway.
    Toxicology and Applied Pharmacology 03/2011; 251(2):130-6. · 3.98 Impact Factor
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    ABSTRACT: In the present study, we aimed to investigate the immunosuppressive activity of jaceosidin, a flavone isolated from Artemisia vestita, on T lymphocytes both in vitro and in vivo, and further explore its potential molecular mechanism. Jaceosidin exerted a significant inhibition on the T cell proliferation and activation induced by concanavalin A (Con A) in a concentration-dependent manner and it also inhibited the secretion of the proinflammatory cytokines such as IL-2, TNF-α and IFN-γ of activated T cells. Further study showed that jaceosidin down-regulated STAT1 activation and T-bet expression in activated T cells. Moreover, in order to investigate the immunosuppressive effect of jaceosidin in vivo, the picryl chloride (PCl)-induced ear contact dermatitis model was performed on BALB/c mice. Jaceosidin significantly ameliorated PCl-induced ear swelling in a dose-dependent manner, which was due to its inhibition of the STAT1/T-bet signaling pathway. In summary, these findings suggest that jaceosidin exerts its immunosuppressive effect both in vitro and in vivo through inhibiting T cell proliferation and activation, which is closely associated with its potent down-regulation of the IFN-γ/STAT1/T-bet signaling pathway.
    European journal of pharmacology 01/2011; 651(1-3):205-11. · 2.59 Impact Factor
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    ABSTRACT: Methylene blue (MB) is a widely studied agent currently under investigation for its properties relating to photodynamic therapy (PDT). Recent studies have demonstrated that MB exhibits profound phototoxicity affecting a variety of tumor cell lines. However, the mechanistic explanation for methylene-blue-mediated photodynamic therapy (MB-PDT) in the context of melanoma therapy is still obscure. In the present study, B16F1 melanoma cells were treated by MB-PDT under different conditions, and thereafter subjected to cell viability detection assays. MB-PDT could induce intense apoptotic cell death through a series of steps beginning with the photochemical generation of reactive oxygen species that activate the caspase-9/caspase-3 apoptosis pathway. Blocking activation of caspase-3 and induction of oxidative stress by caspase inhibitor and by glutathione, respectively, markedly reduced apoptotic cell death in vitro. Importantly, proteomics study defining altered protein expression in treated cells suggests the involvement of several mitochondrial proteins playing important roles in electron transfer chain, implying mitochondrial dysfunction during the treatment. Furthermore, a transplantable mouse melanoma model was utilized to estimate the effectiveness of MB-PDT in vivo. The treated mice displayed decreased tumor size and prolonged survival days, which was associated with enhanced apoptotic cell death. These results, offering solid evidence of the induction of mitochondria-related apoptosis in tumor cells, reveal new aspects of MB-PDT having potential to be a palliative treatment of melanoma.
    Cancer Science 11/2008; 99(10):2019-27. · 3.48 Impact Factor
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    ABSTRACT: Artemisia vestita Wall., a traditional Tibetan medicine, has wide clinical application for inflammatory diseases. However, its molecular mechanism of anti-inflammatory effect is poorly understood. In the present study, we investigated the anti-inflammatory activity and underlying mechanism of the ethanol extract from Artemisia vestita (AV-ext) on lipopolysaccharide (LPS)-induced sepsis. Pretreatment with AV-ext significantly decreased the levels of tumor necrosis factor-alpha (TNF-alpha) in serum and liver and lung tissues, and improved the survival of mice with experimental sepsis. AV-ext also remarkably reduced the expression levels of TNF-alpha, interleukin-1beta and cyclooxygenase-2 in LPS-stimulated RAW 264.7 macrophages and dose dependently suppressed the activation of mitogen-activated protein kinases (MAPKs), such as p38, extracellular signal-regulated kinase (ERK1/2) and c-Jun NH2-terminal kinase (JNK). Furthermore, pretreatment with AV-ext dose dependently inhibited the activation of nuclear factor-kappaB (NF-kappaB), as well as the degradation and phosphorylation of inhibitory kappaB (IkappaB) in LPS-activated RAW 264.7 macrophages. These results collectively reveal that AV-ext inhibits TNF-alpha release from macrophages by suppressing MAPK and NF-kappaB signaling pathways and suggest that AV-ext may be beneficial for the treatment of endotoxin shock or sepsis.
    International Journal of Molecular Medicine 06/2006; 17(5):957-62. · 1.96 Impact Factor
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    ABSTRACT: To provide some pharmacological evidence for its clinical use in inflammatory diseases, anti-inflammatory effect of the aqueous extract from Radix Ophiopogon japonicus (ROJ-ext), a traditional Chinese herb, was examined in mouse and rat models. ROJ-ext significantly inhibited xylene-induced ear swelling and carrageenan-induced paw edema in mice when given orally at doses of 25 and 50 mg/kg. Moreover, ROJ-ext also remarkably suppressed carrageenan-induced pleural leukocyte migration in rats and zymosan A-evoked peritoneal total leukocyte and neutrophil migration in mice, while had no obvious effect on pleural prostaglandin E2 level. Furthermore, two active compounds were isolated from ROJ-ext and identified as ruscogenin and ophiopogonin D. As the results, ROJ-ext, ruscogenin and ophiopogonin D dose-dependently reduced phorbol-12-myristate-13-acetate (PMA)-induced adhesion of HL-60 cells to ECV304 cells, with IC50 of 42.85 microg/ml, 7.76 nmol/l and 1.38 nmol/l, respectively. However, they showed no inhibitory effect on PMA-induced cyclooxygense-2 (COX-2) mRNA expression in ECV304 cells. Ruscogenin and ophiopogonin D also notably decreased zymosan A-induced peritoneal leukocyte migration, in comparison with ROJ-ext. These results demonstrate that ROJ-ext presents remarkable anti-inflammatory activity and ruscogenin and ophiopogonin D are two of its active components, which supported its traditional use in the treatment of various diseases associated with inflammation.
    Biological & Pharmaceutical Bulletin 08/2005; 28(7):1234-8. · 1.85 Impact Factor