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Shen XZ, Koo MW, Cho CH. Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa. World J Gastroenterol 2001; 7:496-9. [PMID: 11819816 PMCID: PMC4688660 DOI: 10.3748/wjg.v7.i4.496] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense.
METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7 d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500 mL·L-1, i.g.) was used to induce gastric mucosa damage.
RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500 mL·L-1 ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 ± 4.2) mm2 was significantly lower (P < 0.01) than the corresponding control (53.7 ± 8.1) mm2.
CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.
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77
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Zhou SY, Mei QB, Liu L, Guo X, Qiu BS, Zhao DH, Cho CH. Delivery of glucocorticoid conjugate in rat gastrointestinal tract and its treatment for ulcerative colitis. Acta Pharmacol Sin 2001; 22:761-4. [PMID: 11749853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
AIM To evaluate colonic delivery and therapeutic effect of the newly synthesized dexamethasone (DX)-dextran (500 000) conjugate (DXD50) in the rat. METHODS The amount of dexamethasone was measured in the contents from different parts of rat gastrointestinal tract and in plasma after ig conjugate. Therapeutic effect of conjugate and DX was tested in trinitrobenzenesulfonic acid-induced colitis in rat. Repair of colitis was assessed by measuring colonic ulceration area, colon weight, and colonic myeloperoxidase (MPO) activity. Systemic immunosuppression of DX was evaluated with weight of thymus and spleen and lymphocyte count in peripheral blood from rat with ulcerative colitis. RESULTS Dexamethasone released from conjugate was mainly distributed in contents of cecum and colon. When DXD50 and DX 0.25 micromol . kg-1 . d-1 were used ig to treat ulcerative colitis in rat, the ulcerative area of colon was reduced by 55.6 % and 33.3 %, respectively whereas colon weight was reduced by 17.9 % and 2.6 %, respectively. The conjugate had no effect on lymphocyte count in peripheral blood, spleen weight, and thymus weight of rat which could be reduced markedly by the same dose of DX (P < 0.05 vs control). CONCLUSION DXD50, which could specifically deliver DX to large intestine, is a promising agent in the treatment of human inflammatory bowel disease.
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78
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Wang WP, Guo X, Koo MW, Wong BC, Lam SK, Ye YN, Cho CH. Protective role of heme oxygenase-1 on trinitrobenzene sulfonic acid-induced colitis in rats. Am J Physiol Gastrointest Liver Physiol 2001; 281:G586-94. [PMID: 11447040 DOI: 10.1152/ajpgi.2001.281.2.g586] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Preliminary studies showed that the inducible form of heme oxygenase (HO-1) was induced and played a protective role in the process of inflammation. The present study investigated the possible role of HO-1 in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats. We measured HO-1 activity in TNBS-induced colitis in rats and analyzed the severity of colitis along with altered HO activity by assessing lesion area and myeloperoxidase activity. HO-1 mRNA and protein expressions were determined at different time points after TNBS induction. Free radical production and inducible nitric oxide synthase (iNOS), which participate in oxidative injury, were also assayed. HO activity and HO-1 gene expression increased markedly after TNBS induction. Administration with tin mesoporphyrin (SnMP), a HO inhibitor, potentiated the colonic damage along with a reduction in HO-1 activity. Furthermore, the reduction of HO-1 expression by SnMP also enhanced reactive oxygen species and iNOS expression, both of which were dramatically increased after the TNBS enema. L-Arginine pretreatment further aggravated the injurious action of SnMP. Our results indicate that HO-1 plays a protective role in the colonic damage induced by the TNBS enema, and the preventive effects probably result from decreased free radical production and inhibition of iNOS expression in colonic tissues.
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79
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Robinson GW, Urquidi J, Singh S, Cho CH. Protein denaturation described by a two-state structural model of liquid water. Cell Mol Biol (Noisy-le-grand) 2001; 47:757-65. [PMID: 11728091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Our laboratory has been involved in expounding an outer neighbor molecular-level structural theory for liquid water in the supercooled and ordinary thermodynamic regimes. This theory, which depends on transformations with increasing temperature or pressure, is consistent with all the properties of this substance, including the ten or so "anomalies", and has been recently used to explain the effect that surrounding water has on proteins. For example, the sharp decrease in the hydration entropies of polar groups can be explained through a consideration of the promotion of ice-Ih-type bonding structure at the expense of the less stable ice-II-type bonding structure. These structural transformations occur in the local neighborhood of the polar group. In this paper we discuss this outer neighbor two-state structural theory for liquid water, the role it plays in explaining water's anomalous properties and its description of protein denaturation both as a function of temperature and pressure.
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Abstract
BACKGROUND Male patients with gastritis are found to have a high risk of developing peptic ulcer diseases. However, how gastritis or gender difference affects gastric ulcer formation is unclear. The present study aimed to investigate the relationship between ethanol-induced acute gastritis and gastric ulcer formation in rats. METHODS Acute gastritis or gastric ulcer was induced in the rat stomach by 80% ethanol or 60% acetic acid, respectively. Rats were killed either with gastritis alone or thereafter at day 1, 3 or 6 after ulcer induction. The number of proliferating and apoptotic cells, the mucosal mucus and prostaglandin E(2) (PGE(2)) level were also determined. RESULTS Male rats with acute gastritis potentiated gastric ulcer formation, while gastritis in female rats prevented ulceration. Female rats with gastritis had a significantly faster ulcer-healing rate. More apoptotic cells were found in the gastritis groups, but only the female gastritis group produced more proliferating cells and had a decrease in the apoptosis-over-proliferation ratio. The mucus level was higher in female rats after ulcer induction. Mucosal PGE(2) level was higher in female rats with acute gastritis. Both mucus and PGE(2) were increased during ulcer healing in both genders. CONCLUSIONS This study shows that gender difference plays a role in the pathogenesis of ulcer formation. The number of cells with apoptosis or proliferation determines, in part, the gender difference on gastric ulcer formation in rats. Gastric PGE(2) not only contributes to this process, but also together with gastric mucus participates in the ulcer-healing process in the stomach.
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81
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Zhou JJ, Pei JM, Wang GY, Wu S, Wang WP, Cho CH, Wong TM. Inducible HSP70 mediates delayed cardioprotection via U-50488H pretreatment in rat ventricular myocytes. Am J Physiol Heart Circ Physiol 2001; 281:H40-7. [PMID: 11406466 DOI: 10.1152/ajpheart.2001.281.1.h40] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To test the hypothesis that heat-shock proteins (HSPs) mediate delayed cardioprotection of prior kappa-opioid receptor (kappa-OR) stimulation, we first correlated cellular injury and viability with the expression of HSP70s in isolated rat ventricular myocytes subjected to prior kappa-OR stimulation with the selective agonist trans-(+/-)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]benzeneacetamide (U-50488H) and delayed lethal simulated ischemia (LSI). Cell injury and viability were indicated by lactate dehydrogenase release and trypan blue exclusion, respectively. The reduced injury and increased viability after pretreatment with U-50488H were concentration dependent and correlated directly with the expression of both stress-inducible (HSP70) and constitutive (HSC70) proteins. The effects mimic those with metabolic inhibition preconditioning (MIP). The cardioprotection against LSI by pretreatment with U-50488H and MIP was abolished and antagonized, respectively, via blockade of the kappa-OR by its selective antagonist, nor-binaltorphimine. We also found that blockade of the production of HSP70 but not HSC70 blocked the inhibitory effect of pretreatment with U-50488H on injury and viability. These observations provide evidence that stress-inducible HSP70 mediates delayed cardioprotection of prior kappa-OR stimulation.
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82
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Ye YN, Liu ES, Li Y, So HL, Cho CC, Sheng HP, Lee SS, Cho CH. Protective effect of polysaccharides-enriched fraction from Angelica sinensis on hepatic injury. Life Sci 2001; 69:637-46. [PMID: 11476185 DOI: 10.1016/s0024-3205(01)01153-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A polysaccharides-enriched fraction from the root of Angelica sinensis, which is known for its antiulcer action on the gastrointestinal tract, was isolated and studied for its hepato-protective effect in rodents. Intra-gastric administration of Angelica sinensis polysaccharides-enriched fraction (AP) at the doses of 50 or 75 mg/kg dose-dependently prevented liver toxicity induced by acetaminophen in mice but did not affect the serum acetaminophen concentration. It normalized the rises of serum alanine transferase (ALT) and hepatic nitric oxide synthase (NOS) activities and the decrease of glutathione level in the liver. It also reduced the hepatic malondialdehyde (MDA) concentration. The protective effect was less evident in the carbon tetrachloride (CCl4)-treated animals including mice and rats. In the rat the elevated serum ALT level was unaffected though the MDA level was similarly reduced by the higher dose of AP. In these animals, CCl4 increased the hepatic glutathione level instead while the NOS activity remained unchanged. These findings suggest that the pathogenic mechanisms of both acetaminophen and CCl4 are different. AP is more effective in the protection against liver damage induced by acetaminophen, which is associated with the glutathione depletion and nitric oxide synthase activation in the liver.
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83
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Ye YN, Liu ES, Shin VY, Koo MW, Li Y, Wei EQ, Matsui H, Cho CH. A mechanistic study of proliferation induced by Angelica sinensis in a normal gastric epithelial cell line. Biochem Pharmacol 2001; 61:1439-48. [PMID: 11331080 DOI: 10.1016/s0006-2952(01)00625-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It has been reported that an extract from Angelica sinensis mainly consisting of polysaccharides (95%) prevented ethanol- or indomethacin-induced gastric mucosal damage (Cho CH et al. Planta Med 2000;66:348-51). However, it is not known whether Angelica sinensis has a direct stimulatory effect on the healing of gastric mucosal lesions. To study the hypothesis that Angelica sinensis has a direct mucosal healing effect in rats and in isolated gastric epithelial cells, we assessed the wound repair in both animals and normal cell culture (RGM-1), as well as [3H]thymidine incorporation, ornithine decarboxylase (ODC) activity, and ODC protein and c-Myc protein expression after different treatments in RGM-1 cells. We found that Angelica sinensis crude extract (ASCE) dose-dependently enhanced gastric ulcer healing in rats and promoted wound repair in RGM-1 cells. It also significantly stimulated [3H]thymidine incorporation and ODC activity in RGM-1 cells in a concentration-dependent manner. ODC and c-Myc protein expression was also increased as a result of this process. DL-alpha-difluoromethyl-ornithine repressed the [3H]thymidine incorporation and ODC activity induced by ASCE. Pretreatment with c-Myc antisense oligodeoxynucleotides blocked the stimulatory action of ASCE on [3H]thymidine incorporation and ODC protein expression. These data suggest that ASCE has a direct mucosal healing effect on gastric epithelial cells, while ODC and c-Myc are closely associated with this effect.
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84
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Lee SH, Naulleau P, Goldberg KA, Cho CH, Jeong S, Bokor J. Extreme-ultraviolet lensless Fourier-transform holography. APPLIED OPTICS 2001; 40:2655-2661. [PMID: 18357280 DOI: 10.1364/ao.40.002655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We demonstrate 100-nm-resolution holographic aerial image monitoring based on lensless Fourier-transform holography at extreme-UV (EUV) wavelengths, using synchrotron-based illumination. This method can be used to monitor the coherent imaging performance of EUV lithographic optical systems. The system has been implemented in the EUV phase-shifting point-diffraction interferometer recently developed at Lawrence Berkeley National Laboratory. Here we introduce the idea of the holographic aerial image-recording technique and present imaging performance characterization results for a 10x Schwarzschild objective, a prototype EUV lithographic optic. The results are compared with simulations, and good agreement is obtained. Various object patterns, including phase-shift-enhanced patterns, have been studied. Finally, the application of the holographic aerial image-recording technique to EUV multilayer mask-blank defect characterization is discussed.
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85
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Oh DK, Cho CH, Lee JK, Kim SY. Increased erythritol production in fed-batch cultures of Torula sp. by controlling glucose concentration. J Ind Microbiol Biotechnol 2001; 26:248-52. [PMID: 11464275 DOI: 10.1038/sj.jim.7000122] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2000] [Accepted: 01/16/2001] [Indexed: 11/08/2022]
Abstract
The effect of glucose concentration on erythritol production by Torula sp. was investigated. The maximum volumetric productivity of erythritol was obtained at an initial glucose concentration of 300 g l(-1) in batch culture. The volumetric productivity was maximal at a controlled glucose concentration of 225 g l(-1), reducing the lag time of the erythritol production. A fed-batch culture was established with an initial glucose concentration of 300 g l(-1) and with a controlled glucose concentration of 225 g l(-1) in medium containing phytic acid as a phosphate source. In this fed-batch culture, a final erythritol production of 192 g l(-1) was obtained from 400 g l(-1) glucose in 88 h. This corresponded to a volumetric productivity of 2.26 g l(-1) h(-1) and a 48% yield.
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Wong BC, Wang WH, Berg DE, Fung FM, Wong KW, Wong WM, Lai KC, Cho CH, Hui WM, Lam SK. High prevalence of mixed infections by Helicobacter pylori in Hong Kong: metronidazole sensitivity and overall genotype. Aliment Pharmacol Ther 2001; 15:493-503. [PMID: 11284778 DOI: 10.1046/j.1365-2036.2001.00949.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Diversity in metronidazole susceptibility and genotypes of Helicobacter pylori have been reported with varying results in different areas. AIMS To investigate the prevalence of multiple strain infection in a symptomatic Chinese population and to determine the metronidazole susceptibility pattern and genotypic characteristics of these infecting strains. METHODS Gastric biopsies from antrum, body and cardia were taken during upper endoscopy in symptomatic patients referred to our department. Pooled cultures and single colony isolates were obtained and tested for metronidazole susceptibility and random amplified polymorphic DNA (RAPD) fingerprint patterns. RESULTS A total of 461 isolates were successfully cultured from 46 patients. Fifty-seven per cent of subjects had metronidazole-resistant strains. Among them, 77% carried a mixture of sensitive and resistant strains, non-uniformly distributed in the gastric mucosa. Mixed genotypes were found by RAPD typing in 24% of subjects. These did not correlate with the metronidazole susceptibility/resistance pattern. CONCLUSION H. pylori infections with mixed metronidazole sensitive/resistant strains and mixed genotypes are common in Hong Kong. This makes it prudent to use bacterial strains from several biopsy sites when testing for traits such as drug resistance or virulence in relation to disease.
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Wang HY, Ma L, Li Y, Cho CH. The role of nitric oxide on cigarette smoke-induced programmed cell death in the gastric mucosa. Scand J Gastroenterol 2001; 36:235-40. [PMID: 11305508 DOI: 10.1080/003655201750074438] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND This study was designed to investigate the effect of cigarette smoking on apoptosis in the gastric mucosa and the role of nitric oxide (NO) in the gas phase and extracts in the tar phase in this pathological process. METHODS Male Sprague-Dawley rats and human gastric epithelial cell line AGS were used in the study. RESULTS Cigarette smoking significantly increased apoptotic bodies in the rat gastric mucosa. However, neither filtered cigarette smoke, in which most of the substances in the tar phase were removed, nor oral administration of the two cigarette smoke extracts produced any effect on apoptosis. Interestingly, in this experiment pretreatment with a NO donor, the chloroform extract (CE) could significantly increase apoptosis. In in vitro study, only the CE induced DNA fragmentation, which could be elevated further by preincubation with a NO donor. The same extract also elevated inducible nitric oxide synthase (iNOS) activity. Inhibition of iNOS by N(G)-nitro-L-arginine methylester hydrochloride (L-NAME) partially abolished CE-induced apoptosis. CONCLUSIONS These findings suggested that exogenous and endogenous NO had a synergistic effect with substances in the tar phase to induce programmed cell death in gastric epithelial cells both in vivo and in vitro.
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88
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Jung N, Kim DS, Kwon HY, Yi YW, Kim D, Kang AD, Cho CH, Hong SS, Lee HS, Bae I. Suppression of collagen-induced arthritis with histone H1. Scand J Rheumatol 2001; 29:222-5. [PMID: 11028842 DOI: 10.1080/030097400750041352] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Besides roles in nucleus mediating the condensation of DNA into chromatin, the involvement of histones in autoimmune diseases, hormone regulation, and killing leukemia cells has been reported. In order to investigate the functions of histones on an autoimmune disease, histone H1 was injected into collagen-induced arthritis (CIA) mice. A dramatic suppression of CIA by histone H1 was observed at a dose of 1 mg/kg bodyweight of mouse. In addition, the increased level of anti-inflammatory cytokine IL-10 was detected in cultured splenocytes from the mouse treated with histone H1. These findings suggest that histone H1 suppresses the collagen-induced arthritis, possibly by increasing the level of IL-10 production.
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Abstract
BACKGROUND/AIMS Patients with peptic ulcer diseases have a high prevalence of coexisting chronic gastritis. The mechanism of how gastritis leads to gastric ulcer formation is yet to be determined. The purpose of this study was to clarify the relationship between gastritis and gastric ulcer in rats. METHODS Ethanol (80% v/v, p.o.) was given repeatedly in rats to induce subchronic gastritis. Gastric ulcer was then induced by 60% acetic acid. RESULTS Findings showed that subchronic gastritis potentiated gastric ulcer formation. It also produced more apoptotic cells, together with an overexpression of tumor necrosis factor-alpha (TNF alpha) in the gastric mucosa. Inhibition of the production/release of TNF alpha by pentoxifylline prevented the increase in apoptosis and the enhancement of susceptibility to ulcerative damage by subchronic gastritis. However, such subchronic gastritis did not further affect the rate of ulcer healing in these animals. CONCLUSION The induction of gastritis resulted in an activation of TNF alpha expression followed by apoptosis in the gastric mucosa. This could lead to an increase in the severity of ulcerative damage in the stomach.
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90
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Jiang XH, Wong BC, Yuen ST, Jiang SH, Cho CH, Lai KC, Lin MC, Kung HF, Lam SK, Chun-Yu Wong B. Arsenic trioxide induces apoptosis in human gastric cancer cells through up-regulation of p53 and activation of caspase-3. Int J Cancer 2001. [PMID: 11146441 DOI: 10.1002/1097-0215(200002)9999:9999<::aid-ijc1039>3.0.co;2-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Arsenic trioxide (As(2)O(3)) can induce clinical remission in patients suffering from acute promyelocytic leukemia, through induction of apoptosis and activation of caspases. We investigated the potential use of As(2)O(3) in human gastric cancer and its possible mechanisms. Human gastric cancer cell lines AGS and MKN-28 were treated with various concentrations (0.1 to 100 microM) of As(2)O(3) for 24 to 72 hr. Apoptosis was determined by acridine orange staining, flow cytometry and DNA fragmentation. Protein levels of p53, p21(waf1/cip1), c-myc, bcl-2 and bax were detected by Western blotting. Effects of As(2)O(3) on caspase-3 protease activity, its protein concentration and cleavage of poly(ADP)-ribose polymerase (PARP) were also studied. As(2)O(3) inhibited cell growth and induced apoptosis in both cell lines, though AGS cells were more sensitive. As(2)O(3) induced apoptosis in AGS cells in a concentration- and time-dependent manner. Treatment resulted in a marked increase in p53 protein levels as early as 4 hr. Co-incubation with p53 anti-sense oligo-nucleotide suppressed As(2)O(3)-induced intracellular p53 over-expression and apoptosis. As(2)O(3) increased the activity of caspase-3, with appearance of its 17 kDa peptide fragment, and cleavage of PARP, with appearance of the 85 kDa cleavage product, both in parallel with the induction of apoptosis. Both the tripeptide caspase inhibitor zVAD-fmk and the specific caspase-3 inhibitor DEVD-fmk partially suppressed As(2)O(3)-induced caspase-3 activation and apoptosis. As(2)O(3) inhibits cell growth and induces apoptosis in gastric cancer cells, involving p53 over-expression and activation of caspase-3. The potential use of this compound in the treatment of gastric cancer is worth further investigation.
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91
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Jiang XH, Wong BC, Yuen ST, Jiang SH, Cho CH, Lai KC, Lin MC, Kung HF, Lam SK, Chun-Yu Wong B. Arsenic trioxide induces apoptosis in human gastric cancer cells through up-regulation of p53 and activation of caspase-3. Int J Cancer 2001. [PMID: 11146441 DOI: 10.1002/1097-0215(200002)9999:9999%3c::aid-ijc1039%3e3.0.co;2-d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Arsenic trioxide (As(2)O(3)) can induce clinical remission in patients suffering from acute promyelocytic leukemia, through induction of apoptosis and activation of caspases. We investigated the potential use of As(2)O(3) in human gastric cancer and its possible mechanisms. Human gastric cancer cell lines AGS and MKN-28 were treated with various concentrations (0.1 to 100 microM) of As(2)O(3) for 24 to 72 hr. Apoptosis was determined by acridine orange staining, flow cytometry and DNA fragmentation. Protein levels of p53, p21(waf1/cip1), c-myc, bcl-2 and bax were detected by Western blotting. Effects of As(2)O(3) on caspase-3 protease activity, its protein concentration and cleavage of poly(ADP)-ribose polymerase (PARP) were also studied. As(2)O(3) inhibited cell growth and induced apoptosis in both cell lines, though AGS cells were more sensitive. As(2)O(3) induced apoptosis in AGS cells in a concentration- and time-dependent manner. Treatment resulted in a marked increase in p53 protein levels as early as 4 hr. Co-incubation with p53 anti-sense oligo-nucleotide suppressed As(2)O(3)-induced intracellular p53 over-expression and apoptosis. As(2)O(3) increased the activity of caspase-3, with appearance of its 17 kDa peptide fragment, and cleavage of PARP, with appearance of the 85 kDa cleavage product, both in parallel with the induction of apoptosis. Both the tripeptide caspase inhibitor zVAD-fmk and the specific caspase-3 inhibitor DEVD-fmk partially suppressed As(2)O(3)-induced caspase-3 activation and apoptosis. As(2)O(3) inhibits cell growth and induces apoptosis in gastric cancer cells, involving p53 over-expression and activation of caspase-3. The potential use of this compound in the treatment of gastric cancer is worth further investigation.
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92
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Jiang XH, Wong BC, Yuen ST, Jiang SH, Cho CH, Lai KC, Lin MC, Kung HF, Lam SK, Chun-Yu Wong B. Arsenic trioxide induces apoptosis in human gastric cancer cells through up-regulation of p53 and activation of caspase-3. Int J Cancer 2001; 91:173-9. [PMID: 11146441 DOI: 10.1002/1097-0215(200002)9999:9999<::aid-ijc1039>3.0.co;2-d] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Arsenic trioxide (As(2)O(3)) can induce clinical remission in patients suffering from acute promyelocytic leukemia, through induction of apoptosis and activation of caspases. We investigated the potential use of As(2)O(3) in human gastric cancer and its possible mechanisms. Human gastric cancer cell lines AGS and MKN-28 were treated with various concentrations (0.1 to 100 microM) of As(2)O(3) for 24 to 72 hr. Apoptosis was determined by acridine orange staining, flow cytometry and DNA fragmentation. Protein levels of p53, p21(waf1/cip1), c-myc, bcl-2 and bax were detected by Western blotting. Effects of As(2)O(3) on caspase-3 protease activity, its protein concentration and cleavage of poly(ADP)-ribose polymerase (PARP) were also studied. As(2)O(3) inhibited cell growth and induced apoptosis in both cell lines, though AGS cells were more sensitive. As(2)O(3) induced apoptosis in AGS cells in a concentration- and time-dependent manner. Treatment resulted in a marked increase in p53 protein levels as early as 4 hr. Co-incubation with p53 anti-sense oligo-nucleotide suppressed As(2)O(3)-induced intracellular p53 over-expression and apoptosis. As(2)O(3) increased the activity of caspase-3, with appearance of its 17 kDa peptide fragment, and cleavage of PARP, with appearance of the 85 kDa cleavage product, both in parallel with the induction of apoptosis. Both the tripeptide caspase inhibitor zVAD-fmk and the specific caspase-3 inhibitor DEVD-fmk partially suppressed As(2)O(3)-induced caspase-3 activation and apoptosis. As(2)O(3) inhibits cell growth and induces apoptosis in gastric cancer cells, involving p53 over-expression and activation of caspase-3. The potential use of this compound in the treatment of gastric cancer is worth further investigation.
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Ye YN, Koo MW, Li Y, Matsui H, Cho CH. Angelica sinensis modulates migration and proliferation of gastric epithelial cells. Life Sci 2001; 68:961-8. [PMID: 11213366 DOI: 10.1016/s0024-3205(00)00994-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A crude extract from Angelica sinensis (ASCE), which mainly consists of polysaccharides, prevents ethanol- or indomethacin-induced gastric mucosal damage and promotes ulcer healing. The aim of this study was to test the hypothesis that ASCE has a direct stimulating effect on gastric epithelial cells for wound healing. We found that ASCE significantly promoted the migration of epithelial cells over an artificial wound on the surface of an RGM-1 monolayer. The extract also stimulated DNA synthesis in a dose-dependent manner and concomitantly increased EGF mRNA expression. Co-incubation of ASCE with anti-EGF antibody reduced the speed of migration and the DNA synthesis, which however were still higher than the control without ASCE. These results strongly suggest that ASCE has a direct wound healing effect on gastric mucosa, and this is acting partially through an EGF-mediated pathway.
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Jiang XH, Wong BCY, Yuen ST, Jiang SH, Cho CH, Lai KC, Lin MCM, Kung HF, Lam SK. Arsenic trioxide induces apoptosis in human gastric cancer cells through up-regulation of p53 and activation of caspase-3. Int J Cancer 2001. [DOI: 10.1002/ijc.1442] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ko JK, Sham NF, Guo X, Cho CH. Beneficial intervention of experimental colitis by passive cigarette smoking through the modulation of cytokines in rats. J Investig Med 2001; 49:21-9. [PMID: 11217144 DOI: 10.2310/6650.2001.34087] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Epidemiologic observations have indicated that cigarette smoking decreases the risk of ulcerative colitis, but the modes of action remain anonymous. The present study aimed to investigate the beneficial effects of passive cigarette smoking using an animal colitis model. We hypothesized that the underlying mechanisms may involve immunoregulation of cytokines. METHODS Experimental colitis was induced in rats by enema administration of 2,4-dinitrobenzene sulfonic acid (DNBS). Passive cigarette smoking by rats was performed for 1 hour once daily, from 3 days before DNBS enema until they were sacrificed on day 8. Other groups of DNBS-treated rats received therapeutic treatment of cyclosporin A or pentoxifylline, a tumor necrosis factor (TNF)-alpha inhibitor. Macroscopic and histologic damage were graded, and the colonic levels of different cytokines and the levels/activities of parameters related to neutrophil activation were also measured. RESULTS DNBS-induced colonic damage was improved in passive-cigarette-smoking rats. This was accompanied by attenuation of the elevated colonic myeloperoxidase and inducible nitric oxide synthase activities and leukotriene B4 level. Likewise, the augmentation in colonic levels of TNF-alpha, interleukin (IL)-1 beta, and IL-6 in colitis rats was also alleviated by passive cigarette smoking. In contrast, the deprivation of colonic IL-10 during colitis was preserved in cigarette-smoking rats. These effects were similarly accomplished by pentoxifylline and, to some degree, by cyclosporin A. CONCLUSIONS The results support the idea that the beneficial effects of passive cigarette smoking in experimental colitis involved immunoregulation of cytokines in colonic tissues.
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Abstract
It has been confusing as to what roles nitric oxide (NO) has in different physiological and pathological mechanisms in various diseases. In the gastrointestinal tract, NO can be either protective or deleterious in different disorders. This depends on what type of nitric oxide synthase (NOS) is involved in these pathological conditions. Constitutive NOS (cNOS) is responsible for production of NO in physiological context. In contrast, inducible NOS (iNOS) produces NO in pathophysiological circumstances. NO is implicated in mechanisms maintaining the integrity of the gastric epithelium. In this connection, it regulates gastric blood flow and directly stimulates gastric mucus secretion by activating soluble guanylate cyclase. A blockade of NO production resulted in an impairment of the vascular response and the subsequent alkaline flux in the lumen. This would impair the restitution process. Endogenous NO also contributes to the inhibition of acid secretion in the stomach. Indeed the adverse action of cigarette smoking on ulcer healing is largely dependent on the deficiency of cNOS and a subsequent depression of gastric blood flow and angiogenesis. To this end, NO may act as a crucial signal to promote endothelial cell differentiation into vascular tubes. In experimental colitis, NO derived from iNOS, together with other free radicals contribute significantly to the inflammatory response in the colon. It is also involved in the ulcerogenic effect of passive smoking on colitis. The mechanism is likely mediated through the interaction with superoxide to produce peroxynitrite, a strong oxidizing agent that initiates lipid peroxidation. In conclusion, NO in low concentration derived from cNOS is cytoprotective by directly acting as an inducer of defense responses in the gastrointestinal tract. However, higher concentrations of NO from iNOS exhibit toxic effects through nitrosative and oxidative stress.
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Cho CH, Kim SS, Jeong MJ, Lee CO, Shin HS. The Na+ -Ca2+ exchanger is essential for embryonic heart development in mice. Mol Cells 2000; 10:712-22. [PMID: 11211878 DOI: 10.1007/s10059-000-0712-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The cardiac Na+ -Ca2+ exchanger 1 (NCX1) is thought to be the major calcium extrusion mechanism and to play an important role in the regulation of intracellular calcium in the heart. The Na+ -Ca2+ exchanger is particularly abundant in the heart, although it is found in a variety of other tissues. To investigate the role of NCX1, we have generated NCX1-deficient mice. Mice heterozygous for the NCX1 mutation showed no discernable phenotype, grew normally, and were fertile; however, no viable homozygote was observed among 175 offspring obtained from intercrosses of heterozygotes. All the homozygous mutant mice died in utero before E10.5. Morphological analysis indicated that homozygotes of NCX1 mutation at E9.5 died with an underdeveloped heart with a dilated pericardium. Microscopic analysis of these embryos showed myocardial cell loss due to apoptosis. The apoptosis was first observed in E8.5 mutant heart. Areas outside the heart appeared normal in the mutant embryos at E8.5. In contrast, at E9.0, various regions of mutant embryos showed extensive cell loss. These results suggest that mutant embryos die owing to cardiac abnormalities caused by apoptotic cell loss, indicating that NCX1 is essential for normal development of the heart.
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Ko JK, Cho CH. Alcohol drinking and cigarette smoking: a "partner" for gastric ulceration. ZHONGHUA YI XUE ZA ZHI = CHINESE MEDICAL JOURNAL; FREE CHINA ED 2000; 63:845-54. [PMID: 11195134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Alcohol consumption and cigarette smoking are two etiologic factors that have a close relationship with peptic ulcer diseases. Chronic active gastritis is reportedly associated with chronic alcohol ingestion. Nonetheless, the inflammatory changes are likely to be related to concurrent Helicobacter pylori infection that is common among alcoholics. Moreover, chronic alcoholism is also correlated with the presence of gastric metaplasia. Both clinically and experimentally, alcohol had been shown to affect the mucosal barrier and histology. These ulcerogenic effects play a crucial role in altering gastric mucosal defense mechanisms. Cigarette smoking is coupled with the initiation and prolongation of gastric ulcers. Epidemiologic data show that cigarette smoking increases both the incidence and relapse rate of peptic ulcer diseases and also delays ulcer healing in humans. Retrospective studies also indicate that cigarette smoking is a key factor in inducing ulcer diseases rather than a linked behavior. The general detrimental effects of cigarette smoking in the gastric mucosa include reduction of circulating epidermal growth factor, increase in tissue free radical production and the presence of free radicals in smoke, together with reduction of mucosal constitutive nitric oxide synthase activity. Furthermore, the alteration of normal gastric mucosal blood flow and angiogenesis and the suppression of cell proliferation contribute largely to the delay in ulcer healing in cigarette smokers. Concurrent consumption of alcohol and cigarette smoking significantly increases the risk of gastric ulcers. In animal experiments, cigarette smoking potentiated ethanol-induced gastric mucosal damage. The reduction of mucus secretion, increase in leukotriene B4 level, increased activities of inducible nitric oxide synthase, xanthine oxidase and myeloperoxidase, and the expression of adhesion molecules in the gastric mucosa accompanied such potentiating effects. Substances other than nicotine in cigarette smoke may also contribute to the above effects.
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Naulleau PP, Cho CH, Gullikson EM, Bokor J. Transmission phase gratings for EUV interferometry. JOURNAL OF SYNCHROTRON RADIATION 2000; 7:405-10. [PMID: 16609228 DOI: 10.1107/s0909049500010670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2000] [Accepted: 07/28/2000] [Indexed: 05/08/2023]
Abstract
The performance of the recently developed EUV phase-shifting point diffraction interferometer (PS/PDI) depends heavily on the characteristics of the grating beamsplitter used in the implementation. Ideally, such a grating should provide throughput of better than 25% and diffraction efficiency, defined as the ratio of the first-diffracted-order power to the zero-order power, variable in the range from approximately 10 to 500. The optimal method for achieving these goals is by way of a phase grating. Also, PS/PDI system implementation issues favor the use of transmission gratings over reflection gratings. Here, the design, fabrication, and characterization of a recently developed transmission phase grating developed for use in EUV interferometry is described.
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Kwon KY, Park CK, Cho CH, Cho WH, Chang ES. Ultrastructural evaluation of preservation and reperfusion effects of low potassium dextran glucose solution in canine allograft lungs. Transplant Proc 2000; 32:2439-41. [PMID: 11120234 DOI: 10.1016/s0041-1345(00)01733-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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