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Tatsuya Ohkawara

Publications and source records attributed to Tatsuya Ohkawara.

15 recordsLinked to original sources
PubMed2006

Polaprezinc protects human colon cells from oxidative injury induced by hydrogen peroxide: relevant to cytoprotective heat shock proteins.

AIM: To investigate the effect of polaprezinc on cellular damage induced by hydrogen peroxide (H(2)O(2)) in human colon CaCo2 cells. METHODS: CaCo2 cells were treated with polaprezinc (10-100 micromol/L) for 6 h. After polaprezinc treatment, the cells were incubated with H(2)O(2) (20 micromol/L) for 1 h. Cell viability was measured by MTT assay. Western blot analysis for heat shock protein (HSP) 27 and HSP72 in the cells was performed. Moreover, cells were pretreated with quercetin (200 micromol/L), an inhibitor of HSP synthesis, 2 h before polaprezinc treatment, and cell viability and the expression of HSP27 and 72 were assessed in these cells. RESULTS: Polaprezinc significantly protected CaCo2 cells from cell damage induced by H(2)O(2), and up-regulated the expressions of HSP27 and HSP72 in the cells (10, 30 and 100 micromol/L of polaprezinc; 35.0% +/- 7.7%, 58.3% +/- 14.6% and 64.2% +/- 8.2%, respectively. P < 0.01 versus polaprezinc-nontreated cells; 6.0% +/- 4.4%). Quercetin inhibited the up-regulation of HSP27 and HSP72 by polaprezinc and diminished the protective effect of polaprezinc against H(2)O(2)-caused injury in the cells. CONCLUSION: Polaprezinc is a useful therapeutic agent for treatment of colitis and its effects depend on the function of cytoprotective HSP in colon.

Anti-Ulcer Agents↗
PubMed2006

Resistance to experimental colitis depends on cytoprotective heat shock proteins in macrophage migration inhibitory factor null mice.

Macrophage migration inhibitory factor plays an important role in inflammatory diseases. We investigated the role of macrophage migration inhibitory factor (MIF) in the development of dextran sulfate sodium (DSS)-induced colitis using MIF null ((-/-)) mice. MIF(-/-) mice given 3% DSS showed no clinical and histological feature of colitis in contrast to wild-type (WT) mice. Lack of MIF suppressed the up-regulation of TNF-alpha and IFN-gamma as Th1-derived cytokines, and increased the level of IL-4 as Th2-derived cytokine in the colon tissues. Moreover, we found that the expressions of heat shock protein (HSP)40 and HSP70 were markedly up-regulated in the colon of MIF(-/-) mice in response to DSS compared with WT mice. Additionally, quercetin, an inhibitor of HSP synthesis, inhibited the up-regulation of HSP40 and 70 expressions and developed DSS-induced colitis in MIF(-/-) mice. Our findings in this study provide more information in the role of MIF in colitis.

Animals↗
PubMed2006

Macrophage migration inhibitory factor has a proinflammatory activity via the p38 pathway in glucocorticoid-resistant ulcerative colitis.

Macrophage migration inhibitory factor (MIF) is a cytokine that has potent anti-steroid effects and might be implicated in the pathogenesis of Ulecrative colitis (UC). We defined the functional role of MIF in the glucocorticoid (GC)-resistant inflammatory response in UC. Twenty-four colonic samples were obtained from GC responsive cases, GC refractory cases, Crohn's disease and controls. LPMC were isolated from surgical specimens. MIF was strongly expressed at mRNA levels in refractory cases rather than responsive cases with UC and controls. IL-8 production from LPMC was significantly reduced by GC addition in responsive cases but not in refractory cases. In refractory cases, anti-MIF Ab ameliorated GC-resistant IL-8 production and p38-MAPK activity of LPMC. In addition, p38-MAPK antagonist SB230580 also ameliorated GC-resistant IL-8 production. These results suggest that MIF has an additional proinflammatory activity through the p38-MAPK pathway in GC-resistant UC.

Adolescent↗
PubMed2006

Effect of macrophage migration inhibitory factor (MIF) on acute graft-versus-host disease in a murine model of allogeneic stem cell transplantation.

Macrophage migration inhibitory factor (MIF) may play an important role in the pathogenesis of acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). We examined whether MIF has an influence on the development of aGVHD and survival using BALB/c-based MIF knock-out (MIF KO) mice. Although MIF expression was observed in lymphocytes that had infiltrated the liver during aGVHD in both wild-type (WT) and MIF KO mice that received bone marrow cells (BM) and spleen cells (SP) from C57BL/6N mice, no significant difference was found in severity of aGVHD or survival rate between the two groups of mice. However, MIF level had decreased at 1 week after HSCT when MIF KO mice were used as the recipients. In the experiment using MIF KO mice as the donors, the recipient mice transplanted with BM and SP from MIF KO mice had significantly lower aGVHD scores on days 14, 21, and 35 than those in the recipient mice transplanted with BM and SP from WT-BALB/c mice. Histopathological findings supported these observations, showing that the bile ducts and lobules in the liver were destroyed by infiltrating MIF-expressing lymphocytes in the recipients of BM and SP from WT-BALB/c mice, while the bile ducts were not destroyed even by infiltrating MIF-deficient lymphocytes in the recipients of BM and SP from MIF KO mice. Therefore, these findings suggest that MIF has an effect on the development of aGVHD in a murine model of allogeneic stem cell transplantation.

Acute Disease↗
PubMed2006

Protective effects of heat shock protein 70 induced by geranylgeranylacetone on oxidative injury in rat intestinal epithelial cells.

OBJECTIVE: Geranylgeranylacetone (GGA), an anti-ulcer agent, has recently been demonstrated to protect a variety of cells and tissues via induction of heat shock protein (HSP)70 against numerous stresses. We investigated whether GGA induces HSP70 and protects against an oxidative stressor, monocrolamine (NH(2)Cl), in a rat intestinal epithelial cell line (IEC-18). MATERIAL AND METHODS: IEC-18 cells pretreated with GGA (0.1-10 microM) were subjected to injury induced by NH(2)Cl. Cell viability was assessed, and endogenous HSP70 levels were determined by enzyme-linked immunosorbent assay in IEC-18 cells. RESULTS: Treatment with GGA (0.1-10 microM) was found rapidly to elevate HSP70 levels and to protect against NH(2)Cl-induced injury in IEC-18 cells. Furthermore, quercetin, an inhibitor of HSP70 synthesis, diminished the protective effects of GGA in IEC-18 cells upon NH(2)Cl-caused injury. CONCLUSIONS: The results of this study suggest that GGA plays an important role in defense mechanisms against oxidative injury in the intestine, primarily via induction of HSP70.

Animals↗
PubMed2006

Protective effect of geranylgeranylacetone on trinitrobenzene sulfonic acid-induced colitis in mice.

Geranylgeranylacetone (GGA) has recently been reported to have a protective effect against ischemic, injurious and apoptotic stress in several tissues. The aim of this study was to determine the effect of GGA on colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in mice. Colitis was induced by intrarectal instillation of TNBS in 50% ethanol in BALB/c mice. Survival, change in body weight and change in wet colon weight were assessed. Histological score in the colon was evaluated 5 days after TNBS treatment. The level of myeloperoxidase (MPO) activity in the colon was also determined. Immunohistochemistry for CD4 in the colon was performed. In addition, the level of heat shock protein (HSP) 70 in the colon was determined by Western blot analysis. Mice were orally treated with GGA (300 mg/kg) 2 h before and every other day after starting TNBS administration. Treatment with GGA markedly improved the survival rate, and reduced the loss of body weight and loss of wet colon weight in mice with TNBS-induced colitis. GGA also suppressed the increase in MPO activity and the number of CD4-positive cells infiltrating the colons of mice with TNBS-induced colitis. Furthermore, treatment with GGA remarkably up-regulated the expression of HSP70 in the colons of mice with TNBS-induced colitis. Our results provide further evidence that GGA has therapeutic potential for intestinal inflammation.

Animals↗
PubMed2005

Regulation of Toll-like receptor 4 expression in mouse colon by macrophage migration inhibitory factor.

Recent studies have indicated that macrophage migration inhibitory factor (MIF) and Toll-like receptor (TLR) play an important role in the regulation of innate immune responses. In this study, we investigated the effect of MIF on the expression of TLR4, a receptor that recognizes lipopolysaccharide, in colon using MIF-deficient mice. TLR4 mRNA expression in the colon tissues was determined by northern blot analysis. Western blot analysis and immunohistochemistry in the colon tissues were performed to evaluate the expression of TLR4 protein. The expressions of TLR4 mRNA and protein were remarkably down-regulated in colon tissues of MIF-deficient mice compared with wild-type mice and up-regulated by treatment with recombinant MIF. Immunohistochemical study revealed the presence of TLR4-positive staining in mononuclear cells in the lamina propria and intraepithelial mononuclear cells as well as weak staining in epithelial cells and crypts in colon tissues of wild-type mice. In contrast, MIF-deficient mice did not show TLR4-positive staining in the colonic mucosa. In MIF-deficient mice injected with recombinant mouse MIF (rMIF), TLR4-positive staining cells were observed in colon tissues similar to the findings in wild-type mice. Administration of dextran sulfate sodium (DSS) up-regulated the expression of TLR4 in the colons of WT mice but not in those of MIF-deficient mice. Furthermore, pretreatment with rMIF up-regulated the expression of TLR4 in response to DSS in MIF-deficient mice. Our results suggest that MIF affects the expression of TLR4 in mouse colon under both normal and colitic conditions.

Animals↗
PubMed2005

Pathophysiological roles of macrophage migration inhibitory factor in gastrointestinal, hepatic, and pancreatic disorders.

Macrophage migration inhibitory factor (MIF) is a unique protein, participating in inflammation, immune response, and cell growth. MIF was first discovered as a lymphokine involved in delayed hypersensitivity and various macrophage functions, including phagocytosis, spreading, and tumoricidal activity. It has been reported that MIF is associated with the pathogenesis of a variety of diseases. MIF expression was increased at inflammatory sites in diseases such as rheumatoid arthritis and glomerulonephritis. In experimental inflammatory disease, blockade of MIF bioactivity inhibited the severity of disease activity. On the other hand, MIF expression is also increased in tumor lesions, and MIF plays a role as a cell growth factor. MIF has been reported to be constitutively expressed in gut, liver, and pancreas. In patients with gastritis, inflammatory bowel disease, hepatitis, and pancreatitis, MIF expression was remarkably increased in both the serum and the local lesions. Blockade of MIF bioactivity inhibited and prevented inflammation in experimental gastritis, colitis, hepatitis, and pancreatitis. On the other hand, MIF expression was higher than that in normal tissues in colonic carcinomas and hepatocellular carcinoma both in vivo and in vitro. Blockade of MIF bioactivity successfully inhibited tumor cell growth in vivo and in vitro. MIF plays important roles in the pathogenesis of gastrointestinal, hepatic, and pancreatic disorders.

Colonic Neoplasms↗
PubMed2005

Geranylgeranylacetone protects mice from dextran sulfate sodium-induced colitis.

OBJECTIVE: Geranylgeranylacetone (GGA) has recently been reported to induce heat shock protein (HSP) 70, which has a protective function against inflammation. We investigated the therapeutic effects of oral administration of GGA on dextran sulfate sodium (DSS)-induced colitis in mice. MATERIALS AND METHODS: BALB/c mice were given 3% DSS solution orally for 7 days to induce colitis. The disease activity of colitis was assessed clinically every day, and histology in the colon was evaluated at 7 days post-DSS. The levels of myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma in the colon tissues were also examined. In addition, expression of HSPs 25, 40, 70 and 90 in the colon tissue was determined by Western blot analysis. Mice were orally administered GGA (50-500 mg/kg) when treatment of DSS started. RESULTS: It was found that GGA significantly reduced the clinical severity of colitis and suppressed the levels of MPO activity, TNF-alpha and IFN-gamma induced by DSS in the colon. On the other hand, GGA enhanced the expression of HSP70 in the colon of mice given DSS. CONCLUSIONS: Taken together, these results suggest that GGA is a new anti-inflammatory drug that could be useful in the treatment of colitis such as inflammatory bowel disease.

Administration, Oral↗
PubMed2005

Polaprezinc (N-(3-aminopropionyl)-L-histidinato zinc) ameliorates dextran sulfate sodium-induced colitis in mice.

OBJECTIVE: Polaprezinc (N-(3-Aminopropionyl)-L-histidinato zinc), an anti-ulcer drug, has been reported to have an anti-inflammatory action in several inflammatory diseases. The aim of this study was to investigate the effect of polaprezinc on dextran sulfate (DSS)-induced colitis in mice. MATERIAL AND METHODS: Mice with colitis induced by DSS were intrarectally treated with polaprezinc (15 mg/kg) or zinc sulfate (7.5 mg/kg) every day after the administration of DSS for 7 days. Disease activity index (DAI) and histological tissue damage were assessed. Levels of myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma in the colon were measured. Expression of heat shock protein (HSP) 25 and HSP70 in the colon was analyzed by Western blot analysis. RESULTS: DAI and histological scores were remarkably reduced in polaprezinc-treated mice with DSS-induced colitis. Polaprezinc suppressed the increase of MPO activity and the production of TNF-alpha and IFN-gamma in the colon tissues of mice with DSS-induced colitis. Expression of HSP25 and HSP70 was remarkably up-regulated in the colon tissues of polaprezinc-treated mice during DSS treatment. CONCLUSIONS: Polaprezinc suppresses DSS-induced colitis in mice, partly through inhibition of production of pro-inflammatory cytokine, suppression of neutrophils accumulation and cytoprotection by overexpression of HSPs. Polaprezinc could be useful in the treatment of inflammatory bowel diseases.

Analysis of Variance↗
PubMed2002

Amelioration of dextran sulfate sodium-induced colitis by anti-macrophage migration inhibitory factor antibody in mice.

BACKGROUND & AIMS: We investigated the effects of macrophage migration inhibitory factor (MIF) antibodies in experimental colitis-induced dextran sulfate sodium (DSS) and trinitrobenzenesulfonic acid (TNBS) and examined whether plasma levels of MIF were elevated in patients with inflammatory bowel disease (IBD). METHODS: BALB/c or C57BL/6 mice were fed 4% DSS in their drinking water for up to 7 days with and without administration of an anti-MIF antibody every 2 days. The severity of inflammation in the cecum and colon was assessed by clinical signs and histologic scoring. Tissue levels of MIF, tumor necrosis factor (TNF)-alpha, interferon gamma (IFN-gamma), interleukin (IL)-4, and matrix metalloproteinase (MMP)-13 messenger RNA (mRNA) were measured. The effects of anti-MIF antibody on chronic colitis induced by TNBS was assessed in BALB/c mice. Plasma MIF concentrations were assayed in patients with Crohn's disease, ulcerative colitis, and healthy controls. RESULTS: During DSS-induced colitis, colonic MIF mRNA expression was increased. Clinical signs and histopathologic features were significantly improved in animals given anti-MIF antibody. DSS-induced up-regulation of colonic TNF-alpha and IFN-gamma were significantly suppressed in animals given the anti-MIF antibody. Colonic IL-4 was decreased during DSS but restored to baseline by the anti-MIF antibody. The anti-MIF antibody prevented MMP-13 up-regulation by DSS and ameliorated TNBS colitis. Plasma MIF was elevated in patients with Crohn's disease or ulcerative colitis compared with healthy controls. CONCLUSIONS: We conclude that anti-MIF antibodies reduce the severity of experimental colitis and limit the up-regulation of Th1-type cytokines. Anti-MIF antibodies are of potential therapeutic use in IBD.

Animals↗