Biomedical subjects

Kozo Hashimoto

Publications and source records attributed to Kozo Hashimoto.

75 records · Page 5Linked to original sources

PubMed2002

[Serum leptin levels in patients with rheumatoid arthritis are correlated with body mass index].

Leptin, a 16-kD protein of the ob gene product, is produced by adipose tissue and acts on the hypothalamus to suppress neuropeptide Y secretion which reduces the appetite. It has been demonstrated that serum leptin levels in healthy subjects are correlated with body mass index(BMI). Leptin is also produced by stimulation of inflammatory cytokines such as tumor necrosis factor(TNF)-alpha and interleukin(IL)-1. Rheumatoid arthritis(RA) is one of the chronic inflammatory diseases in which high serum cytokine levels are noted. In this study, we measured serum leptin levels(s-leptin) by RIA kit in 20 healthy subjects (10 males and 10 females) and 49 RA patients(14 males and 35 females) and the markers for joint inflammation such as ESR and CRP. There was no difference in s-leptin between controls(male: mean +/- SD = 5.6 +/- 3.0 ng/ml; female: 7.8 +/- 4.5 ng/ml) and RA patients(male: 4.9 +/- 3.2 ng/ml; female: 9.1 +/- 5.7 ng/ml). S-leptin was correlated with BMI in both healthy subjects and RA patients. However, there was no correlation between s-leptin and the values of ESR or CRP, disease stages in RA patients. In conclusion, s-leptin in RA patients reflects BMI but not joint inflammation.

Adult↗

PubMedDate not supplied

High glucose alone, as well as in combination with proinflammatory cytokines, stimulates nuclear factor kappa-B-mediated transcription in hepatocytes in vitro.

Diabetes mellitus is frequently associated with coagulation disorders such as coronary heart disease and stroke. We aimed to clarify the molecular mechanism whereby hyperglycemia causes the procoagulant state. HuH7 human hepatocyte cells were treated with high glucose alone or in combination with proinflammatory cytokines, and the effects on the activity of the transcription factor nuclear factor kappa-B (NF-kappaB), which mediates the expression of acute-phase and coagulation-related genes, were examined. The results showed that increasing the medium glucose concentration from 3 to 24 mM significantly enhanced NF-kappaB-luciferase activity by 40% in the presence of insulin. The effect was promoter specific and not mimicked by comparable hyperosmolality with L-glucose. Proinflammatory cytokines such as interleukin-1 and tumor necrosis factor-alpha (TNF-alpha) also stimulated NF-kappaB-dependent transcription and showed an additive effect with high glucose. Similar effects were obtained on acute-phase or coagulation/fibrinolysis-related gene promoters such as fibrinogen or plasminogen activator inhibitor-1, all of which are shown to have NF-kappaB-mediated transcription. Finally, pretreatment of the cells with an antioxidant PDTC completely abolished the effect of high glucose and markedly attenuated that of TNF-alpha, suggesting the involvement of reactive oxygen species. These results suggest that (1) high glucose as well as proinflammatory cytokines have positive effects on NF-kappaB-mediated transcription in an additive manner and enhance coagulation-related gene expression and (2) the effects are mediated, at least partly, by the generation of oxidative stress and may be responsible for the high prevalence of thrombotic disorders in the metabolic syndrome with diabetes, hyperinsulinemia, obesity, and/or inflammation.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Modulation of interleukin-1 receptors followed by endotoxin lipopolysaccharide treatment in the mouse AtT-20 pituitary tumor cell line.

OBJECTIVE: We have previously reported the characterization and regulation of interleukin-1 (IL-1) receptors utilizing [125I]IL-1 binding assay in male C57BL/6 mice and the mouse AtT-20 pituitary tumor cells. In the present study, we examine IL-1 receptors using an immunoblotting method to further characterize the mechanisms regulating the interactions of IL-1 receptors with endotoxin, lipopolysaccharide (LPS). METHODS: We established Western blotting for IL-1 receptors using AtT-20 mouse pituitary tumor cells. RESULTS: Several bands were seen; however, only the 105-kD band was neutralized with a 5-fold excess of IL-1 receptor- blocking peptides, suggesting that this band is specific for IL-1 receptors. Next, we investigated the effect of LPS and IL-1beta on IL-1 receptors. Treatment of AtT-20 cells with 0.01 microg/ml of LPS did not affect IL-1 receptors. In contrast, 1 microg/ml of LPS significantly increased IL-1 receptors in AtT-20 cells compared with the control group. In addition, [125I]IL-1beta binding was markedly increased followed by 1 microg/ml of LPS. In contrast, 1 nM recombinant human IL-1beta significantly decreased IL-1 receptors in AtT-20 cells compared with the control group although treatment of AtT-20 cells with 0.01 nM IL-1beta did not affect IL-1 receptors. LPS (0.1 and 1 microg/ml) did not affect IL-1beta concentrations in the medium of AtT-20 cell culture. IL-1beta concentrations in the homogenates from AtT-20 cells were significantly decreased after 1 microg/ml of LPS treatment but not after 0.01 microg/ml LPS. CONCLUSIONS: These data demonstrate that LPS and IL-1beta differentially modulate IL-1 receptors in AtT-20 cells and LPS-induced modulation of IL-1 receptors may provide a novel mechanism for the actions of LPS to alter pituitary function during endotoxemia. Additional in vivo studies are necessary to determine the physiological relevance of this in vitro phenomenon.

Animals↗