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H Kameda

Publications and source records attributed to H Kameda.

At least 19 recordsLinked to original sources
PubMed2001

Effect of PPAR activators on cytokine-stimulated cyclooxygenase-2 expression in human colorectal carcinoma cells.

Cyclooxygenase-2 (COX-2) expression is up-regulated in colorectal cancer tissue. Peroxisome proliferator-activated receptors (PPARs) are expressed in human colorectal tissue and activation of PPARs can alter COX-2 expression. In macrophages, activation of PPARs down-regulates COX-2 expression. We examined the effect of PPARalpha and PPARgamma ligands on untreated and TNF-alpha-induced COX-2 expression in the human colorectal epithelial cell line HT-29. The expression of PPARalpha and PPARgamma was confirmed in these cells. TNF-alpha, an inflammatory cytokine, increased COX-2 expression via the NFkappaB pathway. In the absence of TNF-alpha, WY14643 (PPARalpha activator) caused an increase, while BRL49653 (PPARgamma activator) did not alter COX-2 expression. When HT-29 cells were incubated with TNF-alpha and WY14643, a further increase in COX-2 expression was detected. Incubation with TNF-alpha and BRL49653 caused an additional twofold increase in COX-2 expression. Our results suggest that both PPARalpha signaling and TNF-alpha signaling increase COX-2 expression by independent pathways, while PPARgamma stimulates COX-2 expression by up-regulation of the TNF-alpha pathway.

Adenocarcinoma↗
PubMed2001

Expression of Gab1 lacking the pleckstrin homology domain is associated with neoplastic progression.

An in vitro transformation system of carcinogen-treated Syrian hamster embryo (SHE) cell cultures represents multistep genetic and nongenetic changes that develop during the neoplastic progression of normal cells to tumor cells in vivo. During this neoplastic progression, SHE cells demonstrate an altered response to epidermal growth factor (EGF). In the present report, we examined the role of the adapter protein Gab1 (Grb2-associated binder-1) in the neoplastic progression of SHE cells. We used two asbestos-transformed SHE cell clones in different neoplastic stages: a 10W+8 clone, which is immortal and retains the ability to suppress the tumorigenicity of tumor cells in cell-cell hybrid experiments, and a 10W-1 clone, which has lost this tumor suppressor ability. 10W+8 cells expressed full-length 100-kDa Gab1 and associated 5.2-kb mRNA. Upon repeated cell passaging, 10W-1 cells showed increasing expression of a novel 87-kDa form of Gab1 as well as 4.6-kb mRNA with diminishing expression of the original 100-kDa Gab1. cDNA encoding the 87-kDa Gab1 predicts a form of Gab1 lacking the amino-terminal 103 amino acids (Gab1(Delta1-103)), which corresponds to loss of most of the pleckstrin homology (PH) domain. Gab1(Delta1-103) retains the ability to be phosphorylated in an EGF-dependent manner and to associate with the EGF receptor and SHP-2 upon EGF stimulation. The endogenous expression of Gab1(Delta1-103) in 10W-1 cells appeared closely related to EGF-dependent colony formation in soft agar. Moreover, transfection and expression of Gab1(Delta1-103), but not Gab1, in 10W+8 cells enhanced their EGF-dependent colony formation in soft agar. These results demonstrate that Gab1 is a target of carcinogen-induced transformation of SHE cells and that the expression of a Gab1 variant lacking most of the PH domain plays a specific role in the neoplastic progression of SHE cells.

Agar↗
PubMed2001

Identification of epidermal growth factor receptor- Grb2-associated binder-1-SHP-2 complex formation and its functional loss during neoplastic cell progression.

The adaptor protein Grb2-associated binder-1 (Gab1) is known to bind to the SHP-2 tyrosine phosphatase on epidermal growth factor (EGF) receptor stimulation. To clarify the roles of these two proteins in EGF receptor (EGFR) signaling and determine their possible alteration during neoplastic cell progression, we studied these proteins in a Syrian hamster embryo (SHE) cell line model of neoplastic progression. Specifically, we used asbestos-transformed SHE fibroblasts: the 10W+8 clone, which is immortal but nontumorigenic; and the 10W2T clone, which is tumorigenic. Gab1 was detected, and the EGF-dependent formation of the EGFR-Gab1-SHP-2 complex was observed in 10W+8 cells. After cloning hamster Gab1 cDNA, exogenous expression of Gab1 significantly enhanced EGF-dependent mitogenic activity in 10W+8 cells. On the other hand, Gab1 was not detected in 10W2T cells, and the EGF-dependent association of SHP-2 with EGFR was also absent. Exogenous Gab1 expression in transfected 10W2T cells restored the EGF-dependent association of SHP-2 with EGFR, although it only showed a marginal effect on EGF-dependent mitogenic activity. Thus, Gab1 plays a pivotal role in the EGFR signaling pathway via the formation of the EGFR-Gab1-SHP-2 complex, and alteration in the expression and function of Gab1 is implicated in the neoplastic progression of SHE cells.

Adaptor Proteins, Signal Transducing↗
PubMed2000

A GATA binding site is involved in the regulation of 15-lipoxygenase-1 expression in human colorectal carcinoma cell line, caco-2.

The data presented implicate a GATA binding site in the transcriptional regulation of 15-lipoxygenase-1 (15-LO-1) gene expression in human colorectal carcinoma Caco-2 cells. High expression of GATA-6 mRNA and protein was observed, while GATA-4 mRNA was expressed at a very low level in Caco-2 cells. The expression of GATA-6 was down-regulated, while 15-LO-1 expression was dramatically up-regulated after treatment with sodium butyrate (NaBT). A study using an electrophoretic mobility shift assay indicated that a GATA binding site of the 15-LO-1 promoter region binds to GATA proteins present in both undifferentiated and, to a lesser extent, NaBT-treated (differentiated) Caco-2 cells. Moreover, that DNA binding shift band was disrupted after the addition of GATA-6 antibody in a supershift assay in the absence of NaBT, suggesting that GATA-6 is bound to the GATA binding site of the 15-LO-1 promoter in undifferentiated cells. In contrast, the addition of GATA-6 antibody did not affect the DNA binding ability in NaBT-induced differentiated cells. On the other hand, mutation of the GATA site of the 15-LO-1 promoter decreased the transactivation of the 15-LO-1 promoter as measured by luciferase activity in both FBS and NaBT cultured cells, indicating an unknown GATA binding protein to up-regulate 15-LO-1 expression. These implicate the GATA site at -240 of the proximal region of the 15-LO-1 promoter in the basic transcription of 15-LO-1 gene expression in Caco-2 cells, with GATA-6 acting to repress 15-LO-1 expression.

Arachidonate 15-Lipoxygenase↗
PubMed1999

Relationship between myocardial cation content and injury in reperfused rat hearts treated with cation channel blockers.

A role for K+ and Ca2+ channel blockers in cardiac contractile dysfunction and myocardial ionic imbalance was examined in isolated rat hearts with 35-min ischemia and 60-min reperfusion. The K+ channel blockers glibenclamide (1-30 microM) and sematilide (1-30 microM), Ca2+ channel blockers diltiazem (0.1-3 microM) and nicardipine (0.03-1 microM) and fast Na+ channel blocker tetrodotoxin (0.01-0.3 microM) were delivered for the last 3-min pre-ischemia. Ischemia-induced increase in Na+ content was attenuated by diltiazem and tetrodotoxin at all concentrations employed and by nicardipine at 0.3 microM, whereas the ischemia-induced loss of K+ was suppressed partially by glibenclamide and sematilide and almost completely by the two drugs in combination. Left ventricular developed pressure of untreated hearts did not recover upon reperfusion, which was associated with increases in myocardial Na+ and Ca2+ contents and decreases in K+ and Mg2+ contents. Glibenclamide and sematilide neither enhanced the post-ischemic recovery of left ventricular developed pressure nor affected cation changes during reperfusion. Diltiazem enhanced the recovery of left ventricular developed pressure and attenuated imbalance of the myocardial Na+ during ischemia and of all myocardial cations examined during reperfusion. The effects of nicardipine on these parameters were small. Tetrodotoxin enhanced the recovery of left ventricular developed pressure and reversed the imbalance of all myocardial cations examined during reperfusion in a concentration-dependent manner. The results suggest that blockade of transmembrane flux of K+ during ischemia plays a minor role in the improvement of post-ischemic contractile recovery, rather blockade of transmembrane flux of Na+ attenuates the ischemia and reperfusion injury.

Animals↗
PubMed1999

The linoleic acid metabolite, 13-HpODE augments the phosphorylation of EGF receptor and SHP-2 leading to their increased association.

In previous studies with Syrian hamster embryo fibroblasts, we found that a specific lipoxygenase metabolite of linoleic acid, 13(S)-hydroperoxyoctadecadienoic acid (HpODE), enhanced epidermal growth factor (EGF) signal transduction in a tumor suppressor gene plus phenotype (supB+); with a diminished response to 13(S)-HpODE in a tumor suppressor gene minus phenotype (supB-). This differential response was attributed to differences in the rate of EGF receptor (EGFR) dephosphorylation. To further define the molecular basis for these observations, in this report we examine the interaction of phosphorylated EGFR with the SH2 domain-containing protein tyrosine phosphatase, SHP-2, a positive modulator of EGF dependent cell growth. SHP-2 associated with phosphorylated EGFR to a greater extent in supB+ cells when compared to supB-. This differential association could not be accounted for by differences between suppressor gene phenotypes in SHP-2 protein level or mutations in the molecular sequence. The addition of 13(S)-HpODE stimulated a concentration-dependent increase in EGF-dependent phosphorylation of SHP-2 and its association with EGFR. A more dramatic response was observed in the supB+ cells. Differences in SHP-2 interaction with EGFR may account, in part, for phenotypic differences in the growth rates and responsiveness to EGF between the supB+ and supB- cells. EGFR-SHP-2 association appears to play an important role in the regulation of EGFR signal transduction.

Animals↗
PubMed1999

Association of human leukocyte antigen class II genes with autoantibody profiles, but not with disease susceptibility in Japanese patients with systemic sclerosis.

OBJECT: To examine the role of human leukocyte antigen (HLA) class II genes in the development of systemic sclerosis (SSc) as well as in the clinical and serologic expression of SSc in patients. METHODS: HLA-DRB1, DRB3, DRB4, DQB1, and DPB1 alleles were determined by genotyping; and serum antinuclear antibodies were identified using indirect immunofluorescence, double immunodiffusion and immunoprecipitation. PATIENTS: One hundred and five Japanese patients with SSc and 104 race-matched healthy controls. RESULTS: Frequencies of DRB1 and DQB1 alleles were not different between SSc patients and healthy controls, while DPB1*0901 was marginally increased in SSc patients. In contrast, SSc-related autoantibodies were closely associated with the clinical features. HLA class II genes were detected as follows: anti-DNA topoisomerase I antibody with diffuse cutaneous involvement, pulmonary fibrosis, and DRB1*1502-DQB1*0601-DPB1*0901; anti-U1RNP antibody with overlapping features of lupus and/or myositis and DRB1*0401/*0802-DQB1*0302; and anticentromere antibody with limited cutaneous involvement and DRB1*0101-DQB1*0501-DPB1*0402. In the analysis of the association of HLA class II and the clinical features in SSc patients significant differences were obtained only for the increased frequencies of arthritis and rheumatoid factor in patients with DRB1*0405 compared to those without. CONCLUSION: HLA class II genes strongly influence the production of SSc-related autoantibodies rather than the development of SSc. In addition, SSc is a composite disease of distinctive subsets defined by serum autoantibodies, which have specific clinical and HLA class II associations.

Adolescent↗
PubMed1998

Immunoglobulin allotype gene polymorphisms in systemic sclerosis: interactive effect of MHC class II and KM genes on anticentromere antibody production.

OBJECTIVE: To examine potential interactions between immunoglobulin (Ig)-allotype gene polymorphisms and susceptibility to systemic sclerosis (SSc) as well as serological expression in SSc patients. METHODS: IgG heavy chain allotypes G1M(f, z), G2M(n+, n-), G3M(b, g) and Ig light chain allotype KM(1, (1, 2), 3) were genotyped in 105 Japanese SSc patients and 47 race matched normal controls using polymerase chain reaction (PCR) based methods. Associations of each Ig allotype with SSc related antinuclear antibodies were examined in combination with or without MHC class II alleles. RESULTS: GM/KM genotypic and allelic frequencies were similar in SSc patients and in normal controls. Frequencies of G1M(f) and G2M(n+) were significantly decreased in anticentromere antibody (ACA) positive SSc patients compared with ACA negative SSc patients (p = 0.04 and 0.02, respectively). Conversely, the presence of DQB1*0501 and KM(1, 2) significantly increased the risk of ACA positivity. CONCLUSION: Ig allotype gene polymorphisms were not associated with susceptibility to SSc. Instead, the results suggested that MHC class II and KM genes are associated with autoimmune responses by interactively promoting the production of ACA.

Antibodies, Antinuclear↗
PubMed1998

[A case of systemic lupus erythematosus associated with spinal epidural hematoma].

A 47 year-old Japanese female who showed transverse myelopathy (TM) due to spinal epidural hematoma diagnosed by MRI in the course of systemic lupus erythematosus (SLE) was reported. She was admitted to Keio University Hospital due to paraplegia, anesthesia of lower extremity, urinary disturbance. Neurological examination revealed transverse disturbance of Th 10. Lumbar spinal cord MRI showed irregular mass that located at epidural region of 9th-11th thoracic vertebrae. When the laminectomy of 9th-11th thoracic vertebrae was performed, hematoma (4.5 cm x 1.5 cm in size) was confirmed and removed completely. Post operative condition was stable and symptoms had been improving gradually. It has been reported that TM associated with SLE was closely related to myelitis. In this case, epidural hematoma was a major cause of TM and MRI was very useful for her diagnosis and treatment. This is the rare case of SLE associated with spinal epidural hematoma and was thought as a important case to consider the cause of neurological complication of SLE.

Female↗
PubMed1998

[The efficacy of combination therapy with prednisolone (PSL) and methotrexate (MTX) on radiographic progression in patients with rheumatoid arthritis (RA)].

A case-controlled study was performed, based on early active RA patients treated with MTX; Prednisolone (PSL) was also given in sixteen patients (PSL + MTX group) and each of them was matched for age and sex with a control who have never received PSL (MTX group). No significant differences in radiographic progression were found between the 2 groups. Analysis of radiographic parameters showed that CRP, erythrocyte sedimentation rate, and titers of serum rheumatoid factors after 6 months treatment and their integral amounts during cource were significantly high in the patients with marked radiographic progression. There was no relationship between radiographic progression and treatment with PSL. These results suggested that the indication of PSL therapy for RA is limited for patients with the poor decrease in the level of CRP, erythrocyte sedimentation rate, and rheumatoid factor by MTX treatment.

Anti-Inflammatory Agents↗
PubMed1997

Re-expression of functional P-selectin molecules on the endothelial cell surface by repeated stimulation with thrombin.

P-selectin (GMP-140, PADGEM, CD62P) is a cell adhesion receptor which is believed to play an important role in inflammatory diseases by supporting leucocyte rolling. P-selectin is located on the granule membrane of Weibel-Palade bodies in resting endothelial cells and is expressed on the cell surface during cellular activation with various stimulators such as thrombin. Thereafter, P-selectin is internalized and sorted to the Golgi region and Weibel-Palade bodies again. However, whether P-selectin is re-expressed upon subsequent cellular stimulation has, to date, been unclear. To address this question, we measured the cellular content and surface expression of P-selectin, using indirect immunofluorescence and confocal laser cytometry. Surface expression of P-selectin reached a maximum < 2 min after thrombin stimulation and declined to basal levels after 180 min. Rechallenge with thrombin induced rapid surface re-expression of P-selectin, which was independent of de novo protein synthesis, since cycloheximide did not inhibit re-expression. Moreover, re-expressed P-selectin supported the adherence of HL60 promyelocytic cells. These results clearly demonstrated that functional P-selectin molecule was recycled after repeated stimulation with thrombin, raising the possibility that P-selectin is involved in chronic inflammation.

Endothelium, Vascular↗
PubMed1997

Methotrexate treatment in patients with adult onset Still's disease--retrospective study of 13 Japanese cases.

OBJECTIVE: To evaluate methotrexate treatment in patients with active adult onset Still's disease (AOSD). METHODS: Methotrexate was initially given as a single weekly oral dose of 5 mg and adjusted individually afterwards in 13 patients with active AOSD. Symptoms and laboratory findings were investigated. RESULTS: Signs of AOSD activity disappeared (remission) in eight patients between 3 and 16 weeks after starting methotrexate. In these patients, significant improvements in C reactive protein, erythrocyte sedimentation rate, white blood count, and serum ferritin were observed at 8, 12, 14, and 16 weeks after starting methotrexate, respectively. In six of these eight patients, steroids or non-steroidal anti-inflammatory drugs could be reduced or discontinued. In four patients methotrexate was not effective despite 12 or 16 weeks of treatment, and one patient discontinued treatment after 2 weeks because of severe nausea. Five patients suffered from adverse reactions, including acute interstitial pneumonia (one patient) and liver toxicity (two patients). Five out of eight patients successfully treated with methotrexate were HLA-DR4 positive (four homozygotes), and all the unsuccessfully treated patients were DR2 positive. CONCLUSIONS: Methotrexate is useful for controlling disease activity in AOSD, not only for refractory patients but also for patients who have never taken steroids or for those with steroid associated toxicity. However, serious adverse reactions can occur, as with rheumatoid arthritis. It is important to determine the critical factors, such as the immunogenetic background, that are associated with response to methotrexate treatment.

Adult↗
PubMed1997

Coexistence of serum anti-DNA topoisomerase I and anti-Sm antibodies: report of 3 cases.

We describe 3 Japanese patients having both serum anti-DNA topoisomerase I and anti-Sm antibodies. All 3 patients had typical features of systemic lupus erythematosus, such as glomerulonephritis, in addition to skin thickening and systemic sclerosis related organ involvement, including pulmonary interstitial fibrosis and renal crisis. This is the first report of the coexistence of these 2 disease specific autoantibodies.

Adolescent↗
PubMed1997

[Toxicity of low-dose methotrexate in rheumatoid arthritis--clinical characteristics in patients with MTX-induced pancytopenia and interstitial pneumonitis].

Pancytopenia and interstitial pneumonitis are one of the most serious and unpredictable adverse effects of low dose, pulse methotrexate (MTX) in treating rheumatoid arthritis (RA). It is important to investigate the historical, clinical or immunologic features associated with the development of such toxicity, in order to use MTX more appropriately. Two hundred eighty four patients (female 230 male 54) with rheumatoid arthritis had been treated with pulse weekly oral MTX with a mean follow-up of 33.2 months. Adverse effects which required the discontinuation of MTX occurred in 47 patients (16.5%). Gastrointestinal toxicity occurred most frequently (14 patients) and liver dysfunction occurred in 9 patients. Four patients (1.4%) developed pancytopenia, and six patients (2.1%) developed interstitial pneumonitis. All patients who developed pancytopenia were old female with long history of active, deforming rheumatoid arthritis, The cumulative dose of MTX ranged from 15 mg to 760 mg at the time pancytopenia developed. Impaired renal function, hypoalbuminemia, and multiple medication were observed, and antinuclear antibodies were positive in most patients. It should be noted that severe stomatitis preceded or accompanied with pancytopenia in all patients. Blood counts returned to the normal level in 7 to 14 days. All patients who developed interstitial pneumonitis were old female. The cumulative dose ranged from 65 mg to 580 mg. Pre-existance of lung diseases, history of adverse effects of other DMARDs, the presence of Raynaud's phenomenon, and antinuclear antibodies appeared to be risk factors for interstitial pneumonitis. All patients recovered with high dose of corticosteroid and mechanical ventilation. Such clinical characteristics that are associated with MTX-induced pancytopenia or interstitial pneumonitis should be reminded in the treatment of rheumatoid arthritis with MTX.

Aged↗
PubMed1997

[Successful treatment of toe gangrene with moderate-dose steroid therapy in a patient with systemic sclerosis (CREST syndrome)].

A 68-year-old woman first noticed Raynaud's phenomenon at the age of 35, and she was diagnosed as having systemic sclerosis (SSc) because of cutaneous calcinosis, sclerodactyly, telangiectasia, sausage-like finger, digital pitting scar in 1971. In October, 1994, she was suffered from cold sensation in her right foot, and on November 2 she noticed the painful ulcers on the right toe, which progressed to be gangrenous. Every antiplatelet or thrombolytic agents including PGE1, argatroban, sarpogrelate hydrochloride and urokinase were unsuccessful. Angiograms revealed marked narrowing of bilateral anterior and posterior tibial and peroneal arteries. Prednisolone 30 mg/day was started, which resulted in successful response within 10 days. Large vessel involvement in SSc patients has been reported to be rare, and its treatment remains to be established. We believe our case help understanding the pathophysiology of such rare manifestation in SSc.

Aged↗