The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Shengli Yang - One of the best experts on this subject based on the ideXlab platform.
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a metabonomic study of hepatitis b induced liver cirrhosis and hepatocellular carcinoma by using rp lc and hilic coupled with mass spectrometry
Molecular BioSystems, 2009Co-Authors: Chunxia Zhao, Xinjie Zhao, Shengli Yang, Jing Chen, Wenzhao Wang, Xin Lu, Jianren Gu, Guowang XuAbstract:Liver cirrhosis and hepatocellular carcinoma (HCC) are fatal sequelaes of chronic hepatitis B in China. The sera from HCC and cirrhosis were profiled by rapid resolution liquid chromatography coupled with quadrupole time-of-flight (Q-TOF) mass spectrometry. Reversed-phased (RP) liquid chromatography and hydrophilic interaction chromatography (HILIC) were used for the data acquisition. The normalized and combined data were handled by chemometric analysis, and the combination proved to be effective and reliable for the orthogonal projection to latent structures (OPLS) analysis. Metabonomic profiles and the potential biomarkers were found based on the OPLS models. Shared and unique structure (SUS) plots were used for the evaluation of the potential biomarkers. Glycocholic Acid, Glycochenodeoxycholic Acid, taurocholic Acid and taurochenodesoxycholic Acid were found to be potential biomarkers related to liver cirrhosis, while dihydrosphingosine and phytosphingosine were potential diagnostic biomarkers of HCC. The other identified metabolites were considered as common potential biomarkers for the two liver diseases. Correlation networks based on these metabolites were also built for the systemic understanding of these diseases and the possible biological implications are discussed. This metabonomic approach may provide insight into discovery and identification of new diagnostic biomarkers for liver cancer and associated diseases.
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high performance liquid chromatography mass spectrometry for metabonomics potential biomarkers for acute deterioration of liver function in chronic hepatitis b
Journal of Proteome Research, 2006Co-Authors: Jun Yang, Xinjie Zhao, Xiaoli Liu, Chang Wang, Peng Gao, Jiangshan Wang, Shengli YangAbstract:Metabonomics methods have been successfully applied to the drug discovery, toxicology, phytochemistry, and clinical fields. Here, we report a self-developed metabonomics platform which is based on high performance liquid chromatography-mass spectrometry (HPLC-MS) technique and applied to the investigation of acute deterioration of liver function in chronic hepatitis B to find the potential biomarkers. Sera from 50 healthy persons and 37 patients with acute deterioration of liver function in chronic hepatitis B were analyzed by HPLC-MS after removal of proteins. After de-noise, peak detection and peak alignment, the data of metabolites were fed to partial least squares discriminant analysis (PLS-DA) to find the potential biomarkers. According to the corresponding tandem mass results, several potential biomarkers were identified: Lysophosphatidyl Choline (LPC) C18:0, LPC C16:0, LPC C18:1, LPC C18:2, and Glycochenodeoxycholic Acid (GCDCA) (or its isomer glycodeoxycholic Acid (GDCA)). On the basis of the relevant literature and pathway databases, the biological significance of the present study is discussed.
Katsuji Oguchi - One of the best experts on this subject based on the ideXlab platform.
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role of caspases 9 and 4 in Glycochenodeoxycholic Acid induced apoptosis in hepg2 cells
The Showa University Journal of Medical Sciences, 2009Co-Authors: Yuko Udaka, Mayumi Tsuji, Toru Iizaka, Hiromichi Tsuchiya, Keiichiro Ohba, Tomoyuki Matsuoka, Michi Ohta, Katsuji OguchiAbstract:It is believed that hepatocellular damage in human chronic cholestatic liver diseases is caused by the accumulation of hydrophobic bile Acids, such as Glycochenodeoxycholic Acid(GCDCA). Previous reports have shown that GCDCA-induced apoptosis is promoted by both mitochondria-mediated and endoplasmic reticulum(ER)stress-associated pathways in HepG2 cells and that these two pathways are linked by the action of caspase-8 on BAP31. However, the interdependence of multiple pathways remains poorly understood and the role of caspases is unclear. Thus, in the present study, we investigated the interactions among the executioner caspases in GCDCA-induced apoptotic HepG2 cells. Cells were treated for 1-24 h with GCDCA(300μM), in the presence or absence of inhibitors of caspase-9, -4 or -3(each at 30μM). Pretreatment of cells with the caspase-9 inhibitor significantly suppressed GCDCA-induced apoptosis ; however, pretreatment of cells with the caspase-4 inhibitor had no effect. Furthermore, pretreatment of cells with the caspase-9 inhibitor significantly reduced GCDCA-induced increases in caspase-3 and -4 activity, as well as the mRNA expression of BiP, a molecular chaperone located in the ER. In contrast, pretreatment of cells with the caspase-4 inhibitor had no effect. These results suggest that, in GCDCA-treated HepG2 cells, caspase-4 acts downstream of both the proapoptotic Bcl-2 protein Bax and caspase-9. Because the major mechanism underlying GCDCA-induced apoptosis involves a mitochondria-mediated pathway, it is unlikely that caspase-4 has a major role in the initiation and promotion of GCDCA-induced apoptosis.
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interaction between caspase 8 activation and endoplasmic reticulum stress in Glycochenodeoxycholic Acid induced apoptotic hepg2 cells
Toxicology, 2007Co-Authors: Toru Iizaka, Mayumi Tsuji, Yuri Morio, Hideto Oyamada, Katsuji OguchiAbstract:Abstract The accumulation of hydrophobic bile Acid, such as Glycochenodeoxycholic Acid (GCDCA), in the liver has been thought to induce hepatocellular damage in human chronic cholestatic liver diseases. We previously reported that GCDCA-induced apoptosis was promoted by both mitochondria-mediated and endoplasmic reticulum (ER) stress-associated pathways in rat hepatocytes. In this study, we elucidated the relationship between these pathways in GCDCA-induced apoptotic HepG2 cells. HepG2 cells were treated with GCDCA (100–500 μM) with or without a caspase-8 inhibitor, Z-IETD-fluoromethyl ketone (Z-IETD-FMK) (30 μM) for 3–24 h. We demonstrated the presence of both apoptotic pathways in these cells; that is, we showed increases in cleaved caspase-3 proteins, the release of cytochrome c from mitochondria, and the expression of ER resident molecular chaperone Bip mRNA and ER stress response-associated transcription factor Chop mRNA. On the other hand, pretreatment with Z-IETD-FMK significantly reduced the increases, compared with treatment with GCDCA alone. Immunofluorescence microscopic analysis showed that treatment with GCDCA increased the cleavage of BAP31, an integral membrane protein of ER, and pretreatment with Z-IETD-FMK suppressed the increase of caspase-8 and BAP31 cleavage. In conclusion, these results suggest that intact activated caspase-8 may promote and amplify the ER stress response by cleaving BAP31 in GCDCA-induced apoptotic cells.
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involvement of endoplasmic reticulum in Glycochenodeoxycholic Acid induced apoptosis in rat hepatocytes
Toxicology Letters, 2006Co-Authors: Shizuma Tsuchiya, Mayumi Tsuji, Yuri Morio, Katsuji OguchiAbstract:Abstract In chronic cholestatic liver diseases, accumulation of hydrophobic bile Acids is thought to damage hepatocytes. The mechanism of how cells die has been an open debate, but apoptotic pathways are known to involve activation of death receptors and mitochondrial dysfunction. Recently apoptosis via an endoplasmic reticulum (ER) stress-mediated pathway was also found. In this study, we examined whether ER stress is induced in rat hepatocytes by treatment with Glycochenodeoxycholic Acid (GCDCA, 50–300 μM for 1–24 h), and if so, whether ER stress-mediated apoptosis occurs in this system. We determined mobility of intracellular calcium ion, activities of calpain and caspase-12, specific to ER stress-mediated apoptosis, and Bip and Chop mRNA expressions, biomarkers of ER stress. We found that GCDCA induces ER-related calcium release within about ten seconds. Significant increases in activities of calpain and caspase-12 were observed after 15 h of GCDCA treatment. Bip and Chop mRNA expressions were increased with the treated GCDCA dose and incubation time. Cytochrome c release from mitochondria peaked in about 2 h of incubation. These results suggest that ER stress is actually induced by GCDCA, though its role in hepatocellular apoptosis may be smaller than mitochondria-mediated pathway. The presence of ER stress might be important in pathogenesis of cholestatic liver diseases.
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the effect of ursodeoxycholic Acid on Glycochenodeoxycholic Acid induced apoptosis in rat hepatocytes
Toxicology, 2005Co-Authors: Shinichi Utanohara, Mayumi Tsuji, Yuri Morio, Shusuke Momma, Katsuji OguchiAbstract:Abstract Ursodeoxycholic Acid (UDCA) has been widely used for treating cholestatic liver diseases. However, in a recent review of clinical trial articles, its therapeutic benefits were not proven. Therefore, we investigated whether UDCA prevents or potentiates Glycochenodeoxycholic Acid (GCDCA)-induced apoptosis in isolated rat hepatocytes. Hepatocellular cytotoxicity was assessed by lactate dehydrogenase (LDH) release, and apoptosis evaluated by DNA fragmentation, caspase activities, release of cytochrome C from mitochondria, and mitochondrial membrane potential change (Δ ψ ). When hepatocytes were co-incubated with GCDCA and UDCA for a short time (2–6 h), GCDCA-induced LDH release was significantly reduced, while prolonged co-incubation (12–20 h) increased it. Similarly, the same co-incubation for a short time resulted in the inhibition of caspase activities and cytochrome C release, while prolonged incubation enhanced them compared with the incubation with GCDCA alone. Furthermore, UDCA significantly promoted the GCDCA-induced Δ ψ decline after 4 h of incubation. These results demonstrated that UDCA reduced GCDCA-induced apoptosis in short incubation, but potentiated it in prolonged incubation. Based on these, we propose a hypothesis that induction of Δ ψ decrease from earlier stage of incubation may be responsible for the aggravation of GCDCA-induced apoptosis in long-term exposure, and would like to raise caution about clinical long-term use of UDCA.
Peter L M Jansen - One of the best experts on this subject based on the ideXlab platform.
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tauroursodeoxycholic Acid protects rat hepatocytes from bile Acid induced apoptosis via activation of survival pathways
Hepatology, 2004Co-Authors: M H Schoemaker, T E Vrenken, Manon Buisthoman, Laura Conde De La Rosa, Klaas Poelstra, Hidde J Haisma, Peter L M Jansen, Rick Havinga, Han MoshageAbstract:Ursodeoxycholic Acid (UDCA) is used in the treatment of cholestatic liver diseases, but its mechanism of action is not yet well defined. The aim of this study was to explore the protective mechanisms of the taurine-conjugate of UDCA (tauroursodeoxycholic Acid [TUDCA]) against Glycochenodeoxycholic Acid (GCDCA)-induced apoptosis in primary cultures of rat hepatocytes. Hepatocytes were exposed to GCDCA, TUDCA, the glyco-conjugate of UDCA (GUDCA), and TCDCA. The phosphatidylinositol-3 kinase pathway (PI3K) and nuclear factor-kappaB were inhibited using LY 294002 and adenoviral overexpression of dominant-negative IkappaB, respectively. The role of p38 and extracellular signal-regulated protein kinase mitogen-activated protein kinase (MAPK) pathways were investigated using the inhibitors SB 203580 and U0 126 and Western blot analysis. Transcription was blocked by actinomycin-D. Apoptosis was determined by measuring caspase-3, -9, and -8 activity using fluorimetric enzyme detection, Western blot analysis, immunocytochemistry, and nuclear morphological analysis. Our results demonstrated that uptake of GCDCA is needed for apoptosis induction. TUDCA, but not TCDCA and GUDCA, rapidly inhibited, but did not delay, apoptosis at all time points tested. However, the protective effect of TUDCA was independent of its inhibition of caspase-8. Up to 6 hours of preincubation with TUDCA before addition of GCDCA clearly decreased GCDCA-induced apoptosis. At up to 1.5 hours after exposure with GCDCA, the addition of TUDCA was still protective. This protection was dependent on activation of p38, ERK MAPK, and PI3K pathways, but independent of competition on the cell membrane, NF-kappaB activation, and transcription. In conclusion, TUDCA contributes to the protection against GCDCA-induced mitochondria-controlled apoptosis by activating survival pathways.
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resistance of rat hepatocytes against bile Acid induced apoptosis in cholestatic liver injury is due to nuclear factor kappa b activation
Journal of Hepatology, 2003Co-Authors: M H Schoemaker, W M Gommans, Laura Conde De La Rosa, M Homan, Pieter Klok, C Trautwein, Harry Van Goor, Klaas Poelstra, Hidde J Haisma, Peter L M JansenAbstract:Abstract Background/Aims : To examine the extent and mechanisms of apoptosis in cholestatic liver injury and to explore the role of the transcription factor nuclear factor-kappa B in protection against bile Acid-induced apoptosis. Methods : Cholestatic liver injury was induced by bile duct ligation in Wistar rats. Furthermore, primary cultures of rat hepatocytes were exposed to Glycochenodeoxycholic Acid (GCDCA), tauroursodeoxycholic Acid (TUDCA), taurochenodeoxycholic Acid (TCDCA) and to cytokines. Apoptosis was determined by TUNEL-staining, active caspase-3 staining, activation of caspase-8, -9 and -3. Results : Limited hepatocyte apoptosis and an increased expression of NF-κB-regulated anti-apoptotic genes A1 and cIAP2 were detected in cholestatic rat livers. Bcl-2 expression was restricted to bile duct epithelium. In contrast to TCDCA and TUDCA, GCDCA induced apoptosis in a Fas-associated protein with death domain (FADD)-independent pathway in hepatocytes. Although bile Acids do not activate NF-κB, NF-κB activation by cytokines (induced during cholestasis) protected against GCDCA-induced apoptosis in vitro by upregulating A1 and cIAP2. Conclusions : GCDCA induces apoptosis in a mitochondria-controlled pathway in which caspase-8 is activated in a FADD-independent manner. However, bile Acid-induced apoptosis in cholestasis is limited. This could be explained by cytokine-induced activation of NF-κB-regulated anti-apoptotic genes like A1 and cIAP2.
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Resistance of rat hepatocytes against bile Acid-induced apoptosis in cholestatic liver injury is due to nuclear factor-kappa B activation
2003Co-Authors: Schoemaker Marieke, Gommans, Willemijn Maria, Conde De La Rosa, Laura, Buist-homan Manon, Klok Pieter, Trautwein Christian, Van Goor Harry, Poelstra Klaas, Haisma H.j., Peter L M JansenAbstract:Background/Aims: To examine the extent and mechanisms of apoptosis in cholestatic liver injury and to explore the role of the transcription factor nuclear factor-kappa B in protection against bile Acid-induced apoptosis. Methods: Cholestatic liver injury was induced by bile duct ligation in Wistar rats. Furthermore, primary cultures of rat hepatocytes were exposed to Glycochenodeoxycholic Acid (GCDCA), tauroursodeoxycholic Acid (TUDCA), taurochenodeoxycholic Acid (TCDCA) and to cytokines. Apoptosis was determined by TUNEL-staining, active caspase-3 staining, activation of caspase-8, -9 and -3. Results: Limited hepatocyte apoptosis and an increased expression of NF-kappaB-regulated anti-apoptotic genes A1 and cIAP2 were detected in cholestatic rat livers. Bcl-2 expression was restricted to bile duct epithelium. In contrast to TCDCA and TUDCA, GCDCA induced apoptosis in a Fas-associated protein with death domain (FADD)-independent pathway in hepatocytes. Although bile Acids do not activate NF-kappaB, NF-kappaB activation by cytokines (induced during cholestasis) protected against GCDCA-induced apoptosis in vitro by upregulating A1 and cIAP2. Conclusions: GCDCA induces apoptosis in a mitochondria-controlled pathway in which caspase-8 is activated in a FADD-independent manner. However, bile Acid-induced apoptosis in cholestasis is limited. This could be explained by cytokine-induced activation of NF-kappaB-regulated anti-apoptotic genes like A1 and cIAP2. (C) 2003 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights reserved
Dong Hwan Sohn - One of the best experts on this subject based on the ideXlab platform.
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pf2401 sf standardized fraction of salvia miltiorrhiza and its constituents tanshinone i tanshinone iia and cryptotanshinone protect primary cultured rat hepatocytes from bile Acid induced apoptosis by inhibiting jnk phosphorylation
Food and Chemical Toxicology, 2007Co-Authors: Eunjeon Park, Yuzhe Zhao, Younchul Kim, Dong Hwan SohnAbstract:Abstract Bile Acid-induced hepatocyte apoptosis plays an important role in cholestatic liver disease, and the role of apoptosis may be of therapeutic interest in preventing liver disease. The dried root of Salvia miltiorrhiza Bunge (Labiatae) has been used traditionally to treat liver diseases. We investigated the antiapoptotic effects of a standardized fraction of S. miltiorrhiza (PF2401-SF) and its components, tanshinone I, tanshinone IIA, and cryptotanshinone, in primary cultured rat hepatocytes. PF2401-SF was enriched with tanshinone I (11.5%), tanshinone IIA (41.0%), and cryptotanshinone (19.1%). Glycochenodeoxycholic Acid (GCDC)-induced apoptosis, as shown by DNA fragmentation, poly(ADP-ribose) polymerase cleavage, and activation of caspases-8, -9, and -3. PF2401-SF and its components, tanshinone I, tanshinone IIA, and cryptotanshinone showed antiapoptotic activity. Treatment with PF2401-SF or with its components significantly inhibited the generation of intracellular reactive oxygen species. Hydrophobic bile Acids activate c-Jun-NH2-terminal kinase (JNK), p38 mitogen-activated protein kinases (MAPK), and extracellular signal-regulated kinase 1/2, and PF2401-SF inhibited the phosphorylation of JNK and p38. All three components of PF2401-SF inhibited JNK phosphorylation. Addition of inhibitors of MAPK showed that inhibition of JNK decreased apoptosis. These data indicate that PF2401-SF and its components protect hepatocytes from GCDC-induced apoptosis in vitro by inhibiting JNK.
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honokiol reduces oxidative stress c jun nh2 termial kinase phosphorylation and protects against Glycochenodeoxycholic Acid induced apoptosis in primary cultured rat hepatocytes
Planta Medica, 2006Co-Authors: Eunjeon Park, Soyeon Kim, Yuzhe Zhao, Dong Hwan SohnAbstract:Hydrophobic bile Acid-induced apoptosis plays an important role in cholestatic liver disease, and its prevention may be of therapeutic interest. The aim of this study was to investigate the protective effect of honokiol on Glycochenodeoxycholic Acid-induced apoptosis in primary cultured rat hepatocytes. Glycochenodeoxycholic Acid is a hydrophobic bile salt that accumulates intrahepatically during cholestasis and induces hepatocyte apoptosis at pathophysiological concentrations. Primary rat hepatocytes were pretreated with honokiol at concentrations of 40, 20 and 10 μM 5 min before Glycochenodeoxycholic Acid treatment. Incubation of hepatocytes with Glycochenodeoxycholic Acid at a concentration of 100 μM for 4 h induced apoptosis as shown by DNA fragmentation, chromatin condensation and cleavage of poly(ADP-ribose) polymerase. Pretreatment with honokiol at concentrations of 40, 20 and 10 μM significantly inhibited the generation of intracellular reactive oxygen species and reduced activation of caspases-8, -9, and -3 and cleavage of poly-(ADP-ribose) polymerase. Glycochenodeoxycholic Acid treatment up-regulated phosphorylation of stress-activated protein kinase/c-jun-NH2-terminal kinase which was inhibited by honokiol treatment. Inhibition of stress-activated protein kinase/c-jun-NH2-terminal kinase phosphorylation by SP600125 protected hepatocytes from apoptosis induced by Glycochenodeoxycholic Acid. These data indicate that honokiol protects hepatocytes from apoptosis induced by Glycochenodeoxycholic Acid in vitro and this protection may be due to reduced oxidative stress and inhibition of stress-activated protein kinase/c-jun-NH2-terminal kinase phosphorylation.
M H Schoemaker - One of the best experts on this subject based on the ideXlab platform.
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tauroursodeoxycholic Acid protects rat hepatocytes from bile Acid induced apoptosis via activation of survival pathways
Hepatology, 2004Co-Authors: M H Schoemaker, T E Vrenken, Manon Buisthoman, Laura Conde De La Rosa, Klaas Poelstra, Hidde J Haisma, Peter L M Jansen, Rick Havinga, Han MoshageAbstract:Ursodeoxycholic Acid (UDCA) is used in the treatment of cholestatic liver diseases, but its mechanism of action is not yet well defined. The aim of this study was to explore the protective mechanisms of the taurine-conjugate of UDCA (tauroursodeoxycholic Acid [TUDCA]) against Glycochenodeoxycholic Acid (GCDCA)-induced apoptosis in primary cultures of rat hepatocytes. Hepatocytes were exposed to GCDCA, TUDCA, the glyco-conjugate of UDCA (GUDCA), and TCDCA. The phosphatidylinositol-3 kinase pathway (PI3K) and nuclear factor-kappaB were inhibited using LY 294002 and adenoviral overexpression of dominant-negative IkappaB, respectively. The role of p38 and extracellular signal-regulated protein kinase mitogen-activated protein kinase (MAPK) pathways were investigated using the inhibitors SB 203580 and U0 126 and Western blot analysis. Transcription was blocked by actinomycin-D. Apoptosis was determined by measuring caspase-3, -9, and -8 activity using fluorimetric enzyme detection, Western blot analysis, immunocytochemistry, and nuclear morphological analysis. Our results demonstrated that uptake of GCDCA is needed for apoptosis induction. TUDCA, but not TCDCA and GUDCA, rapidly inhibited, but did not delay, apoptosis at all time points tested. However, the protective effect of TUDCA was independent of its inhibition of caspase-8. Up to 6 hours of preincubation with TUDCA before addition of GCDCA clearly decreased GCDCA-induced apoptosis. At up to 1.5 hours after exposure with GCDCA, the addition of TUDCA was still protective. This protection was dependent on activation of p38, ERK MAPK, and PI3K pathways, but independent of competition on the cell membrane, NF-kappaB activation, and transcription. In conclusion, TUDCA contributes to the protection against GCDCA-induced mitochondria-controlled apoptosis by activating survival pathways.
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resistance of rat hepatocytes against bile Acid induced apoptosis in cholestatic liver injury is due to nuclear factor kappa b activation
Journal of Hepatology, 2003Co-Authors: M H Schoemaker, W M Gommans, Laura Conde De La Rosa, M Homan, Pieter Klok, C Trautwein, Harry Van Goor, Klaas Poelstra, Hidde J Haisma, Peter L M JansenAbstract:Abstract Background/Aims : To examine the extent and mechanisms of apoptosis in cholestatic liver injury and to explore the role of the transcription factor nuclear factor-kappa B in protection against bile Acid-induced apoptosis. Methods : Cholestatic liver injury was induced by bile duct ligation in Wistar rats. Furthermore, primary cultures of rat hepatocytes were exposed to Glycochenodeoxycholic Acid (GCDCA), tauroursodeoxycholic Acid (TUDCA), taurochenodeoxycholic Acid (TCDCA) and to cytokines. Apoptosis was determined by TUNEL-staining, active caspase-3 staining, activation of caspase-8, -9 and -3. Results : Limited hepatocyte apoptosis and an increased expression of NF-κB-regulated anti-apoptotic genes A1 and cIAP2 were detected in cholestatic rat livers. Bcl-2 expression was restricted to bile duct epithelium. In contrast to TCDCA and TUDCA, GCDCA induced apoptosis in a Fas-associated protein with death domain (FADD)-independent pathway in hepatocytes. Although bile Acids do not activate NF-κB, NF-κB activation by cytokines (induced during cholestasis) protected against GCDCA-induced apoptosis in vitro by upregulating A1 and cIAP2. Conclusions : GCDCA induces apoptosis in a mitochondria-controlled pathway in which caspase-8 is activated in a FADD-independent manner. However, bile Acid-induced apoptosis in cholestasis is limited. This could be explained by cytokine-induced activation of NF-κB-regulated anti-apoptotic genes like A1 and cIAP2.