Clinical and Basic Aspects of Interleukin-17

科学研究費補助金研究成果報告書研究種目: 基盤研究(B)研究期間: 2003～2005課題番号: 15390232研究代表者: 安藤 朗（滋賀医科大学・医学部・講師

IL-17 induces inflammatory responses in human colonic myofibroblasts

科学研究費補助金研究成果報告書研究種目: 基盤研究(B)研究期間: 2001～2002課題番号: 13470119研究代表者: 安藤 朗（滋賀医科大学・医学部・助手

Prebiotic treatment reduced preneoplastic lesions through the downregulation of toll like receptor 4 in a chemo-induced carcinogenic model

Germinated barley foodstuff contains prebiotics which are reported to have anti-cancerous effects in colorectal cancer model, but the detailed mechanism remains unclear. Recent studies revealed that the role of microbiota was strongly related to the regulation of incidence and progression of colorectal cancer. The aim of this study was to examine the anti-neoplastic mechanism by prebiotics. Azoxymethane treated F344 rats were used as the sporadic cancerous model. After azoxymethane injection, either a control or germinated barley foodstuff diet was administered to the rats for another 5 weeks, and the number of abberant crypt foci, toll like receptor 4, Kirsten rat sarcoma viral oncogene homolog, adenomatous polyposis coli tumor suppressor gene and cyclooxygenase 2 mRNA expression of colonic mucosa and cecal short chain fatty acids were examined. The germinated barley food stuff significantly attenuated the number of abberant crypt focis and the expression of toll like receptor 4 and cyclooxygenase 2 mRNA, compared to the control group. In addition, the cecal butyrate production in the germinated barley foodstuff group was significantly higher than that in the control. In conclusion, this prebiotic treatment for colorectal cancer may be useful without causing the adverse effects seen in either anti-cancer drugs or anti-inflammatory drugs

Energy Metabolism in Japanese Patients with Crohn’s Disease

We investigated energy expenditure in hospitalized patients with Crohn’s disease (CD), and determined optimal energy requirements for nutritional therapy. Sixteen patients (5 women and 11 men, mean age 36 year old, mean BMI 18.7 kg/m2) and 8 healthy volunteers were enrolled in this study. Measured resting energy expenditure (mREE) levels were determined by indirect calorimetry. The mREEs in CD patients were significantly higher than those of healthy controls (24.4 ± 2.4 kcal/kg/day vs 21.3 ± 1.7 kcal/kg/day). However, mREEs in CD patients were significantly lower than predicted REEs (pREEs) calculated by the Harris-Benedict equation (26.4 ± 2.5 kcal/kg/day). Furthermore, mREE/pREE values were lower in undernourished patients than in well-nourished patients. CD patients had hyper-metabolic statuses evaluated by mREE/body weight, but increased energy expenditure did not contribute to weight loss in these patients. In conclusion, nutritional therapy with 25–30 kcal/ideal body weight/day (calculated by mREE × active factor) may be optimal for active CD patients, while higher energy intake values pose the risk of overfeeding

Serum Concentrations of Trace Elements in Patients with Crohn’s Disease Receiving Enteral Nutrition

We investigated the trace element status in Crohn’s disease (CD) patients receiving enteral nutrition, and evaluated the effects of trace element-rich supplementation. Thirty-one patients with CD were enrolled in this study. All patients were placed on an enteral nutrition regimen with Elental® (Ajinomoto pharmaceutical. Ltd., Tokyo, Japan). Serum selenium, zinc and copper concentrations were determined by atomic absorption spectroscopy. Serum selenoprotein P levels were determined by an ELISA system. Average serum levels of albumin, selenium, zinc and copper were 4.1 ± 0.4 g/dl, 11.2 ± 2.8 µg/dl, 71.0 ± 14.8 µg/dl, and 112.0 ± 25.6 µg/dl, respectively. In 9 patients of 31 CD patients, serum albumin levels were lower than the lower limit of the normal range. Serum selenium, zinc and copper levels were lower than lower limits in 12 patients, 9 patients and 1 patient, respectively. Serum selenium levels significantly correlated with both serum selenoprotein P levels and glutathione peroxidase activity. Supplementation of selenium (100 µg/day) and zinc (10 mg/day) for 2 months significantly improved the trace element status in CD patients. In conclusion, serum selenium and zinc levels are lower in many CD patients on long-term enteral nutrition. In these patients, supplementation of selenium and zinc was effective in improving the trace element status

Interleukin(IL)-36α and IL-36γ Induce Proinflammatory Mediators from Human Colonic Subepithelial Myofibroblasts

Background: Interleukin (IL)-36 cytokines are recently reported member of the IL-1 cytokine family. However, there is little information regarding the association between IL-36 cytokines and gut inflammation. In the present study, we investigated the biological activity of IL-36α and IL-36γ using human colonic subepithelial myofibroblasts (SEMFs). Methods: The mRNA expression and the protein expression of target molecules in SEMFs were evaluated using real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. The intracellular signaling of IL-36 cytokines was analyzed using Western blot analysis and small interfering RNAs (siRNAs) specific for MyD88 adaptor proteins (MyD88 and IRAK1) and NF-κB p65. Results: IL-36α and IL-36γ significantly enhanced the secretion of IL-6 and CXC chemokines (CXCL1, CXCL2, and CXCL8) by SEMFs. The combination of IL-36α/γ and IL-17A or of IL-36α/γ and tumor necrosis factor (TNF)-α showed a synergistic effect on the induction of IL-6 and CXC chemokines. The mRNA expression of proinflammatory mediators induced by IL-36α and/or IL-36γ was significantly suppressed by transfection of siRNA for MyD88 or IRAK1. Both inhibitors of mitogen activated protein kinases (MAPKs) and siRNAs specific for NF-κBp65 significantly reduced the expression of IL-6 and CXC chemokines induced by IL-36α and/or IL-36γ. Conclusion: These results suggest that IL-36α and IL-36γ contribute to gut inflammation through the induction of proinflammatory mediators

DA-Raf1, a competent intrinsic dominant-negative antagonist of the Ras–ERK pathway, is required for myogenic differentiation

Ras activates Raf, leading to the extracellular-regulated kinase (ERK)–mitogen-activated protein kinase pathway, which is involved in a variety of cellular, physiological, and pathological responses. Thus, regulators of this Ras–Raf interaction play crucial roles in these responses. In this study, we report a novel regulator of the Ras–Raf interaction named DA-Raf1. DA-Raf1 is a splicing isoform of A-Raf with a wider tissue distribution than A-Raf. It contains the Ras-binding domain but lacks the kinase domain, which is responsible for activation of the ERK pathway. As inferred from its structure, DA-Raf1 bound to activated Ras as well as M-Ras and interfered with the ERK pathway. The Ras–ERK pathway is essential for the negative regulation of myogenic differentiation induced by growth factors. DA-Raf1 served as a positive regulator of myogenic differentiation by inducing cell cycle arrest, the expression of myogenin and other muscle-specific proteins, and myotube formation. These results imply that DA-Raf1 is the first identified competent, intrinsic, dominant-negative antagonist of the Ras–ERK pathway