Browsing by Author "Wu, Ming-Shiang"

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A potential role for Helicobacter pylori heat shock protein 60 in gastric tumorigenesis
(2010-02-05)
Lin, Chen-Si
;
He, Pei-Juin
;
Tsai, Nu-Man
;
Li, Chi-Han
;
Yang, Shang-Chih
Helicobacter pylon has been found to promote the malignant process leading to gastric cancer. Heat shock protein 60 of H. pylori (HpHSP60) was previously been identified as a potent immunogene. This Study investigates the role of HpHSP60 in gastric cancer carcinogenesis. The effect of HpHSP60 on cell proliferation, anti-death activity, angiogenesis and cell migration were explored. The results showed that HpHSP60 enhanced migration by gastric cancer cells and promoted tube formation by umbilical vein endothelial cells (HUVECs); however, HpHSP60 did not increase cell Proliferation nor was this protein able to rescue gastric cancer cells from death. Moreover, the results also indicated HpHSP60 had different effects on AGS gastric cancer cells or THP-1 monocytic cells in terms of their expression of pro-inflammatory cytokines, which are known to be important to cancer development. We propose that HpHSP60 may trigger the initiation of carcinogenesis by inducing pro-inflammatory cytokine release and by promoting angiogenesis and metastasis. Thus, this extracellular pathogen-derived HSP60 is potentially a vigorous virulence factor that can act as a carcinogen during gastric tumorigenesis. (C) 2010 Elsevier Inc. All rights reserved.
Antibodies against Helicobacter pylori heat shock protein 60 aggravate HSP60-mediated proinflammatory responses
(2011-08-01)
Liao, Kuang-Wen
;
Lin, Chen-Si
;
Chen, Wen-Liang
;
Yang, Chu-Ting
;
Lin, Ching-Min
Anti-Helicobacter pylori heat shock protein 60 (HpHSP60) antibodies are Usually found in H. pylori-infected patients and are known to be associated with the progression of gastric diseases. However, the effects of these antibodies on the functions of HpHSP60 have not been identified. This study aims to investigate the effects of the interaction between anti-HSP60 antibodies and HpHSP60 on inflammatory responses. Anti-HpHSP60 polyclonal sera and monoclonal antibodies (mAbs) were produced to evaluate their effects on HpHSP60-induced IL-8 and TNF-alpha activity. The results indicated that anti-HpHSP60 polyclonal sera collected from patients infected with H. pylori or from rabbit and mice immunized with HpHSP60 could significantly enhance HpHSP60-mediated IL-8 and TNF-alpha secretion from monocytic THP-1 cells. Similar effects were also found with anti-HpHSP60 mAbs. Further analysis revealed that this phenomenon was only carried out by anti-HpHSP60 antibody but not by other non-specific mAbs. Moreover, the non-specific mAbs decreased the synergism of HpHSP60 and anti-HpHSP60 mAbs in proinflammatory cytokine induction. Herein, we have examined the role of anti-HpHSP60 antibody in host immune responses for the first time. This study demonstrated that H. pylori HSP60/mAbs could modulate helico-bacterial pathogenesis by increasing IL-8 and TNF-alpha production. The pathogen-specific antibodies may execute potential immune functions rather than recognize or neutralize microbes. (C) 2011 Elsevier Ltd. All rights reserved.
Characterizing the polymeric status of Helicobacter pylori heat shock protein 60
(2009-10-16)
Lin, Ching-Yi
;
Huang, Yu-Shan
;
Li, Chi-Han
;
Hsieh, Yuan-Ting
;
Tsai, Nu-Man
Helicobacter pylori heat shock protein 60 (HpHsp60) was first identified as an adhesion molecule associated with H. pylori infection. Here we have analyzed the structure of HpHsp60 via amino acid BLAST, circular dichroism, and electrophoresis and the results indicate that most recombinant HpHsp60 molecules exist as dimers or tetramers, which is quite different from Escherichia coli Hsp60. Treatment of human monocytic cells THP-1 with HpHsp60 was found to up-regulate a panel of cytokines including IL-1 alpha, IL-8, IL-10, IFN-gamma, TNF-alpha, TGF-beta, GRO, and RANTES. Carboxymethylated HpHsp60 molecules with a switched oligomeric status were able to further enhance NF-kappa B-mediated IL-8 and TNF-alpha secretion in THP-1 cells compared to unmodified HpHsp60 molecules. These results indicated that the oligomeric status of HpHsp60s might have an important role in regulating host inflammation and thus help facilitate H. pylori persistent infection. (C) 2009 Elsevier Inc. All rights reserved.
Cholesteryl alpha-D-glucoside 6-acyltransferase enhances the adhesion of Helicobacter pylori to gastric epithelium
(2020-03-13)
Jan, Hau-Ming
;
Chen, Yi-Chi
;
Yang, Tsai-Chen
;
Ong, Lih-Lih
;
Chang, Chia-Chen
Helicobacter pylori, the most common etiologic agent of gastric diseases including gastric cancer, is auxotrophic for cholesterol and has to hijack it from gastric epithelia. Upon uptake, the bacteria convert cholesterol to cholesteryl 6 '-O-acyl-alpha-D-glucopyranoside (CAG) to promote lipid raft clustering in the host cell membranes. However, how CAG appears in the host to exert the pathogenesis still remains ambiguous. Herein we identified hp0499 to be the gene of cholesteryl alpha-D-glucopyranoside acyltransferase (CGAT). Together with cholesteryl glucosyltransferase (catalyzing the prior step), CGAT is secreted via outer membrane vesicles to the host cells for direct synthesis of CAG. This significantly enhances lipid rafts clustering, gathers adhesion molecules (including Lewis antigens and integrins alpha 5, beta 1), and promotes more bacterial adhesion. Furthermore, the clinically used drug amiodarone was shown as a potent inhibitor of CGAT to effectively reduce the bacterial adhesion, indicating that CGAT is a potential target of therapeutic intervention. Jan et al. identify cholesteryl alpha-D- glucopyranoside acyltransferase as a key enzyme in Helicobacter pylori's synthesis of cholesteryl 6'-O-acyl-alpha-D-glucopyranoside, which promotes bacterial adhesion. This study provides insights into the H. pylori-induced pathogenesis and therapeutic strategies against it.
Helicobacter pylori-derived Heat shock protein 60 enhances angiogenesis via a CXCR2-mediated signaling pathway
(2010-06-25)
Lin, Chen-Si
;
He, Pei-Juin
;
Hsu, Wei-Tung
;
Wu, Ming-Shiang
;
Wu, Chang-Jer
Helicobacter pylori is a potent carcinogen associated with gastric cancer malignancy. Recently. H. pylori Heat shock protein 60 (HpHSP60) has been reported to promote cancer development by inducing chronic inflammation and promoting tumor cell migration. This study demonstrates a role for HpHSP60 in angiogenesis, a necessary precursor to tumor growth. We showed that HpHSP60 enhanced cell migration and tube formation, but not cell proliferation, in human umbilical vein endothelial cells (HUVECs). HpHSP60 also indirectly promoted HUVEC proliferation when HUVECs were co-cultured with supernatants collected from HpHSP60-treated AGS or THP-1 cells. The angiogenic array showed that HpHSP60 dramatically induced THP-1 cells and HUVECs to produce the chemotactic factors IL-8 and GRO. Inhibition of CXCR2, the receptor for IL-8 and GRO, or downstream PLC beta 2/Ca2+-mediated signaling, significantly abolished HpHSP60-induced tube formation. In contrast, suppression of MAP K or PI3 K signaling did not affect HpHSP60-mediated tubulogenesis. These data suggest that HpHSP60 enhances angiogenesis via CXCR2/PLC beta 2/Ca2+ signal transduction in endothelial cells. (C) 2010 Elsevier Inc. All rights reserved.
Helicobacter pylori-derived heat shock protein 60 increases the induction of regulatory T cells
(2013-05-01)
Hsu, Wei-Tung
;
Wu, Ming-Shiang
;
Wu, Chang-Jer
;
Chen, Chia-Hung
;
Jian, Ting-Yan
Helicobacter pylori-derived heat shock protein 60 increases the induction of regulatory T-cells associated with persistent infection
(2018-06-01)
Hsu, Wei-Tung
;
Ho, Shu-Yi
;
Jian, Ting-Yan
;
Huang, Han-Ning
;
Lin, Yu-Ling
Local Treg responses are involved in Helicobacter pylori-related inflammation and clinical outcomes after infection, and H. pylori-derived HSP60 (HpHSP60) is an important virulence factor associated with gastric carcinogenesis. This study to investigate the role of HpHSP60 in immunosuppression, particularly with regard to whether it could induce the production of Treg cells. For this purpose, human peripheral blood mononuclear cells (PBMCs) were treated with or without HpHSP60 in the presence of an anti-CD3 mAb to determine the effect of HpHSP60 on cell proliferation. In this report, HpHSP60 decreased the expression of CDK4 to significantly arrest the proliferation of mitogen-stimulated T-cells, which correlated with the induction of Treg cells. Moreover, monocytic cells were essential for the induction of HpHSP60-induced Treg cells via the secretion of IL-10 and TGF-beta after treatment with HpHSP60. Blockage of HpHSP60 with specific monoclonal antibodies significantly reduced the colonization of H. pylori and the expression of Treg cells in vivo. Overall, our results suggest that HpHSP60 could act on macrophages to trigger the expression of IL-10 and TGF-beta, thereby leading to an increase in Treg cells and inhibition of T-cell proliferation.
Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence
(2016-01-01)
Jan, Hau-Ming
;
Chen, Yi-Chi
;
Shih, Yu-Yin
;
Huang, Yu-Chen
;
Tu, Zhijay
Helicobacter pylori infects approximately half of the human population and is the main cause of various gastric diseases. This pathogen is auxotrophic for cholesterol, which it converts upon uptake to various cholesteryl alpha-glucoside derivatives, including cholesteryl 6'-acyl and 6'-phosphatidyl alpha-glucosides (CAGs and CPGs). Owing to a lack of sensitive analytical methods, it is not known if CAGs and CPGs play distinct physiological roles or how the acyl chain component affects function. Herein we established a metabolite-labelling method for characterising these derivatives qualitatively and quantitatively with a femtomolar detection limit. The development generated an MS/MS database of CGds, allowing for profiling of all the cholesterol-derived metabolites. The subsequent analysis led to the unprecedented information that these bacteria acquire phospholipids from the membrane of epithelial cells for CAG biosynthesis. The resulting increase in longer or/and unsaturated CAG acyl chains helps to promote lipid raft formation and thus delivery of the virulence factor CagA into the host cell, supporting the idea that the host/pathogen interplay enhances bacterial virulence. These findings demonstrate an important connection between the chain length of CAGs and the bacterial pathogenicity.
Preferential induction of transforming growth factor-beta production in gastric epithelial cells and monocytes by Helicobacter pylori soluble proteins
(2007-11-01)
Wu, Ming-Shiang
;
Lin, Jaw-Town
;
Hsu, Ping-Ning
;
Lin, Ching-Yi
;
Hsieh, Yuan-Ting
Background. The cytokines induced by Helicobacter pylori, as well as the intricate balance of proinflammatory and anti-inflammatory cytokines, are relevant to the outcomes of H. pylori infection. Transforming growth factor (TGF)-beta and interleukin (IL)-10 are 2 vital anti-inflammatory cytokines that regulate mucosal immunity in various inflammatory and infectious diseases. Methods. To elucidate whether host-bacteria interaction can influence TGF-beta and IL-10 production, we investigated the expression of TGF-beta and IL-10 in various mammalian cell lines preincubated with H. pylori and other enteric bacteria. Results. The amount of TGF-beta protein, but not IL-10, was significantly increased after stimulation with H. pylori, but other enteric bacteria did not induce TGF-beta production. Different H. pylori strains isolated from patients with gastritis, peptic ulcer, gastric cancer and strains with cagA or vacA isogenic mutations showed similar effects on TGF-beta induction, indicating that this effect was a constitutional characteristic of H. pylori and independent of cagA and vacA status. Conclusion. The results imply the presence of a protein factor ( termed "TGF-beta-inducing protein") that induces production of TGF-beta. In view of the multiple effects of TGF-beta, we conclude the TGF-beta-inducing protein of H. pylori might mediate the immune response and contribute to the pathogenesis of H. pylori infection.