Biomedical subjects

E Fukawa

Publications and source records attributed to E Fukawa.

11 recordsLinked to original sources

PubMed2002

Thrombin-induced expression of RANTES mRNA through protease activated receptor-1 in human synovial fibroblasts.

OBJECTIVE: To examine the effects of thrombin on RANTES mRNA expression through protease activated receptor in synovial fibroblasts in patients with rheumatoid arthritis (RA). METHODS: A semiquantitative reverse transcriptase-polymerase chain reaction and reporter gene assay were performed using cultured human synovial fibroblasts from patients with RA. The up regulatory effects of thrombin on RANTES mRNA expression were tested. In addition, the roles of protease activated receptors (PARs) were analysed. RESULTS: PAR-1 and PAR-3, but not PAR-4, were expressed in synovial fibroblasts. Thrombin induced RANTES mRNA expression in a time dependent manner in synovial fibroblasts expressing PAR-1. A reporter gene assay showed that thrombin-induced RANTES gene expression was through PAR-1, but not PAR-3. CONCLUSIONS: Thrombin induced RANTES mRNA expression through a PAR-1 mediated pathway, possibly indicating that thrombin has an important role in migration of inflammatory cells by RANTES to the synovium in patients with RA.

Apoptosis Regulatory Proteins↗

PubMed2001

Bile acids regulate RANTES gene expression through its cognate NF-kappaB binding sites.

Regulated upon activation, normal T-cells expressed and secreted (RANTES) mainly migrates memory type CD4+ T-lymphocytes to inflamed tissues. In this study, we examined effects of bile acids on RANTES gene expression in human hepatoma cells. Upon stimulation with hydrophobic bile acids, RANTES proteins were clearly increased. Semiquantitative RT-PCR analysis revealed that chenodeoxycholic acid (CDCA) induced RANTES mRNA expression. Moreover, RANTES was transcriptionally induced in two hepatoma cell lines by CDCA, presumably via its cognate NF-kappaB binding sites in the RANTES promoter. Electrophoretic mobility shift assay revealed that hydrophobic bile acids induced DNA-binding activity of NF-kappaB. Additionally, the magnitude of inducibility was closely associated with the hydrophobicity of bile acids. In conclusion, we might indicate that bile acids induced RANTES gene expression in human hepatoma cells, possibly suggesting that bile acids play an important role in migration of inflammatory cells by RANTES to the liver in patients with primary biliary cirrhosis.

Antibodies↗

PubMed1999

Human T cell leukemia virus type I-associated myelopathy in a patient with systemic lupus erythematosus.

A case of human T cell leukemia virus type I (HTLV-1) associated myelopathy (HAM)/tropical spastic paraparesis (TSP) with 14-year history of systemic lupus erythematosus (SLE) is reported. For 9 years, the numbness of the feet and sacral region progressed with occasional urinary incontinence and constipation. She was admitted to hospital due to gait disturbance and aggravation of SLE and the diagnosis of HAM/TSP was confirmed, indicating that HTLV-1 infection is associated with the development of not only HAM/TSP but also SLE.

Blotting, Western↗

PubMed1997

Effect of 1 alpha-hydroxyvitamin D3 on serum levels of thyroid hormones in hyperthyroid patients with untreated Graves' disease.

We performed a randomized, open prospective study to determine the effect of 1 alpha-hydroxyvitamin D3 [1 alpha (OH)D3] on hyperthyroidism in patients with untreated Graves' disease. At the time of entry into the study, 30 patients were randomly assigned to receive a daily dose of 30 mg methimazole (MMI) (group A, n = 15) or the same dose of MMI supplemented with 1.5 micrograms 1 alpha (OH)D3 (group B, n = 15). These treatment regimens were continued for 24 weeks, and physicians were allowed to adjust MMI dosage during follow-up visits. Blood samples were collected, and serum concentrations of free triiodothyronine (FT3), free thyroxine (FT4), T3, T4, thyrotropin (TSH), alkaline phosphatase (ALP), and TSH-receptor antibody (TRAb) were determined. During the follow-up periods, all patients became euthyroid. The dose of MMI was not significantly different between these two groups. In contrast, decreases in mean serum FT3 and FT4 levels, as well as in mean serum T3 and T4 levels, were greater in group B. Correspondingly, the reciprocal increase in the mean TSH level was more prominent in group B. Mean TRAb levels did not differ between the two groups. Mean serum ALP levels in group B were significantly lower than in group A at 24 weeks. Thus, we suggest that concomitant administration of 1 alpha (OH)D3 is useful for treating hyperthyroidism in patients with Graves' disease.

Adolescent↗

PubMed1995

Identification and characterization of guanine nucleotide-sensitive melatonin receptors in chicken brain.

Specific melatonin receptors present in crude membrane preparations of chicken forebrain were identified by specific binding activity of 2-[125I]iodomelatonin and melatonin-dependent inhibition of forskolin-stimulated adenylate cyclase activity by a pertussis toxin-sensitive mechanism. The membrane-bound melatonin receptors were successfully solubilized with digitonin, and the ligand binding activity was shown to be preserved in solubilized membranes when compared with that of crude membranes. In both fractions, melatonin receptors consisted of two binding components with picomolar and nanomolar affinity. The ligand binding activity of solubilized receptors was decreased after treatment with guanine nucleotides, and guanosine 5'-(gamma-thio)triphosphate (GTP gamma S) induced a transformation of the high affinity receptors to low affinity state. Moreover, [35S]GTP gamma S was indicated to bind to solubilized membranes in a melatonin-dependent fashion. These results demonstrate the existence of functional melatonin receptors--G proteins coupling in digitonin-solubilized membranes of chicken forebrain membranes.

Animals↗

PubMed1995

Natural course of diabetic peripheral neuropathy in spontaneous-onset diabetic Chinese hamsters.

We investigated metabolic and pathological changes in the peripheral nerve of the spontaneous-onset diabetic Chinese hamster. Electrophysiological examination revealed that the motor nerve conduction velocity was significantly decreased at 10 months and afterwards, however, the F-wave latency was significantly increased at 5 months and afterwards. Concerning sciatic nerve contents of sorbitol, myo- and scyllo-inositol, the content of sorbitol was not significantly increased at 5 months, but, myo- and scyllo-inositol were significantly decreased at 5 months and thereafter. At 10 and 15 months, however, sciatic nerve content of sorbitol was significantly increased. On morphological examination, loss of large myelinated fiber and reciprocal increase in degenerative fiber were also seen in sciatic nerve, but not in tibial nerve, at 5 months. At 15 months, these morphological changes were also found in the tibial as well as the sciatic nerve. Thus, we may hypothesize that F-wave latency is useful in the detection of initial diabetic neuropathy, and that the initial pathological changes in diabetic neuropathy of diabetic Chinese hamsters are predominantly found in the proximal site of peripheral nerves.

Aging↗

PubMed1994

Relative glucocorticoid potency revisited.

To determine the relative potency of synthetic glucocorticoids, glucocorticoid receptor expressing cells were transfected with a hormone-inducible reporter gene, and were cultured in the presence of various glucocorticoid ligands. Hormonal inducibility was determined by means of a chloramphenicol acetyltransferase assay. Dexamethasone and prednisolone, as well as cortisol, induced the expression of the reporter gene in a dose-dependent fashion. The relative potency of each ligand was in this order when inducibility was quantitatively assessed. In conclusion, the transcription assay described here may be a convenient and alternative method to evaluate the relative potency of given glucocorticoids.

Animals↗

PubMed1994

Homologous down-regulation of the glucocorticoid receptor down-modulates cellular hormone responsiveness in human histiocytic lymphoma U937 cells.

One of the determinants of cellular responsiveness to glucocorticoid hormone is the concentration of the receptor protein. It is well-known that cellular receptor levels are down-regulated by the cognate ligands, but the biological significance of this homologous down-regulation of the receptor has not yet been completely understood. We showed that in human histiocytic lymphoma cell line U937 the cellular glucorticoid receptor was homologously down-regulated by means of both ligand binding and Western immunoblot experiments. Reduction of the receptor was saturable, and the receptor levels tended to return to the levels before treatment after 3-day culture in the presence of the hormone. Next, using the cells which were pretreated with the hormone for 0 to 3 days, hormonal inducibility of the transiently-transfected reporter gene and the inhibitory effect of the hormone on cellular 3-O-methyl glucose uptake were determined. Hormonal inducibility of the reporter gene was progressively reduced, and thereafter tended to be restored, apparently in accordance with the cyclic change in amount of the receptor. The glucose uptake inhibiting effect of the hormone also revealed this cyclic pattern. In summary, in U937 cells glucocorticoid receptor was homologously down-regulated and may play a pivotal role in attenuating hormone responsiveness.

3-O-Methylglucose↗

PubMed1993

Repression of glucocorticoid receptor function by the anti-rheumatic gold compound aurothiomalate.

We describe functional interaction between the anti-rheumatic water-soluble gold compound aurothiomalate and glucocorticoid receptors. Aurothiomalate contains gold in the Au(I) state, and Au(I) alone, not thiomalate or malate, reduced the ligand-binding activity of the glucocorticoid receptor. Au(I) also interfered with the productive interaction between the glucocorticoid receptor and the cognate target DNA sequences and repressed the transactivation function of the receptor. Thus, Au(I) variably modulates glucocorticoid receptor-mediated intracellular signals.

Animals↗

PubMed1993

Successful treatment of refractory polymyositis with pulse intravenous cyclophosphamide and low-dose weekly oral methotrexate therapy.

A 36-year-old woman gradually developed dysphagia and muscle weakness of the lower extremities. Diagnosis of polymyositis was given from elevation of serum creatine kinase and pathological findings of a muscle biopsy. Despite oral prednisolone and intravenous pulse methylprednisolone therapy, her muscle weakness persisted, and then pulse intravenous cyclophosphamide (IVCY) therapy was initiated and repeated five times in total, which resulted in significant improvement in muscle strength. Thereafter, weekly administration of methotrexate at low dosage further normalized the serum creatine kinase level. We may conclude that IVCY and low-dose weekly methotrexate together could be an alternative in refractory polymyositis.

Administration, Oral↗

PubMed1992

In vitro monitoring activation by the ligands and specific DNA-binding of the glucocorticoid receptors.

The glucocorticoid receptor is a member of the steroid and thyroid hormone receptor superfamily and acts as a ligand-activated transcription factor. To reconstitute the molecular mechanisms underlying the cellular response to soluble receptor ligands, we have exploited a cell-free system that exhibits glucocorticoid-induced activation of the latent cytosolic glucocorticoid receptor to an active DNA-binding species. We demonstrate here that cytosol from a rat hepatoma cell, M1.19, contains glucocorticoid receptor-specific immunoreactivities and target DNA-binding activities. Moreover, specific DNA-binding activities of M1.19 cytosol were dose-dependently induced by dexamethasone treatment, and linearly correlated with the hormonal induction of chloramphenicol acetyltransferase activity at the corresponding concentrations. These results indicate that the cytosolic glucocorticoid receptor could be converted in a DNA-binding form under cell-free conditions and the ligand appears to play a crucial role in the direct control of the level of functional activity of a given ligand-receptor complex.

Animals↗