Yoshikazu Ohtsuka

MIP-2 secreted by epithelial cells increases neutrophil and lymphocyte recruitment in the mouse intestine

BACKGROUND Invasion of the intestinal mucosa by leucocytes is a characteristic of intestinal inflammation but the role of the epithelium in orchestrating this recruitment has not been examined in vivo. Cultured intestinal epithelial cells secrete a wide variety of chemokines, often in response to agents present in the intestinal lumen. Macrophage inflammatory protein 2 (MIP-2) is a chemokine that attracts neutrophils, and its secretion from intestinal epithelial cells is enhanced by inflammatory stimuli such as interleukin 1β. We hypothesised that the production of MIP-2 by epithelial cells would increase leucocyte migration into the intestine. AIM To study the effects of a chemokine secreted from intestinal epithelial cells in vivo. METHODS MIP-2 was expressed in the mouse intestinal epithelium using an epithelial cell specific promoter from the gene encoding the intestinal fatty acid binding protein. The intestines of these transgenic mice were then analysed. RESULTS Epithelial cells from transgenic mice expressed MIP-2 but wild-type mice did not. Neutrophil recruitment, examined by myeloperoxidase (MPO) staining and total MPO activity per unit weight of intestine, was significantly increased in transgenic mice in both the small intestine and proximal colon, and this was blocked by anti-MIP-2 antibody treatment. Both intraepithelial and lamina propria lymphocytes were also increased in transgenic mice. They showed chemotactic activity to MIP-2 in the Boyden chambers and expressed MIP-2 receptor (CXCR-2) mRNA confirmed by reverse transcription-polymerase chain reaction. CONCLUSION These experiments are the first to show a functional role for epithelial chemokines in vivo and reveal an unexpected role for the neutrophil chemokine MIP-2 in controlling mucosal lymphocyte migration.

Effects of bifidobacterium breve supplementation on intestinal flora of low birth weight infants

Abstract Background : It is known that the bifidobacteria flora play important roles in mucosal host defense and can prevent infectious diseases. Because bacterial populations develop during the first day of life, the authors examined whether the early administration of bifidobacteria has a positive effect on the health of low birth weight infants.

The estimated incidence of cystic fibrosis in Japan.

BACKGROUND It is believed that the incidence of cystic fibrosis (CF) among Asiatic races, including the Japanese, is very rare. This epidemiological study was carried out to investigate the incidence of CF in Japan. METHODS We collected literature describing CF cases among pure Japanese and found 124 cases reported as CF during the 43 years from 1951, when the first case was reported, to 1993. Only 104 cases (57 male and 47 female patients) of 124 cases met our diagnostic criteria. RESULTS A simple calculation based on the number of reported CF cases and of live births after 1980 suggested that the incidence of CF is about 1 in 350,000 in the Japanese population. Twenty-nine (27.9% of the total) of 30 patients diagnosed in the neonatal period presented symptoms of meconium ileus, an incidence higher than that reported for the white population. CONCLUSIONS Our study results suggest that the incidence of CF in the Japanese population is even rarer than had been estimated before and that there is a genetic difference between northern European and Japanese populations.

Bifidobacterium breve enhances transforming growth factor beta1 signaling by regulating Smad7 expression in preterm infants.

Objectives: Transforming growth factor (TGF) &bgr;1 displays a broad spectrum of activities in mucosal regulation, including induction of oral tolerance, potent anti-inflammatory effects, mucosal IgA expression and effects on epithelial cell proliferation and differentiation. The present study examined the effect of probiotics on the immunologic system of preterm infants in relation to TGF-&bgr; signaling. Methods: Subjects comprised 19 preterm infants divided into 2 groups: receiving Bifidobacterium breve supplementation (B. breve group) and without supplementation (controls). Blood samples were collected from both groups on days 0, 14 and 28 after birth. Serum cytokine levels were measured using enzyme-linked immunosorbent assay, and expression levels of the TGF-&bgr; signaling molecule, Smad, were examined using semiquantitative reverse transcriptase-polymerase chain reaction. Results: Serum TGF-&bgr;1 level was elevated on day 14 and remained elevated on day 28 in the B. breve group. Level of messenger RNA expression was enhanced for Smad3 and reduced for Smad7 (antagonistic Smad) after B. breve administration relative to levels in controls on day 28. Conclusions: These results demonstrated that the administration of B. breve to preterm infants can up-regulate TGF-&bgr;1 signaling and may possibly be beneficial in attenuating inflammatory and allergic reactions in these infants.

Effects of highly purified eicosapentaenoic acid on erythrocyte fatty acid composition and leukocyte and colonic mucosa leukotriene B4 production in children with ulcerative colitis.

Background n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a treatment for ulcerative colitis (UC). However, the efficacy of n-3 PUFAs against UC has not been examined in children. Therefore, the authors investigated the effects of eicosapentaenoic acid (EPA) on fatty acid composition and leukotriene (LT) production in children with UC. Methods For 2 months the authors administered highly purified EPA ethyl ester (EPA-E) (1.8 g/d) to children with UC in remission. Colonic mucosal histology, fatty acid composition of erythrocyte membrane phospholipids, and LTB4 production by leukocytes and colonic mucosa were measured before and 2 months after the initiation of EPA-E treatment. Results No patients relapsed during the study period, and no significant differences were detected in laboratory findings obtained before and 2 months after the initiation of EPA-E ingestion. There were no significant differences in mucosal histologic scores before and 2 months after EPA-E treatment. The EPA levels in erythrocyte membranes 2 months after the initiation of EPA-E treatment were significantly higher than before treatment, but the other fatty acids showed no significant changes. LTB4 production by leukocytes and rectal mucosa after 2 months of EPA-E treatment was significantly lower than before treatment. Conclusion EPA-E treatment increased the levels of EPA in erythrocytes and decreased LTB4 levels produced by leukocytes and colonic mucosa. To assess the concomitant clinical changes, we should examine the long-term effects of EPA-E ingestion on the maintenance of remission in children with UC.

Dextran sulfate sodium-induced inflammation is enhanced by intestinal epithelial cell chemokine expression in mice.

Dextran sulfate sodium (DSS) induces an inflammatory bowel disease-like colitis in animals. To determine the contribution of epithelium to inflammation in the intestine, we examined the effects of DSS in transgenic mice that specifically secrete macrophage inflammatory protein-2 (MIP-2) from the intestinal epithelium. We first confirmed the production of MIP-2 from intestinal epithelial cells by Western blots in transgenic mice. MIP-2 transgenic mice were therefore an appropriate model to examine the role of epithelial cell chemokines in an inflammatory state induced by DSS. We then examined the neutrophil migration into the intestine and the effect of DSS on this migration by myeloperoxidase staining. There was an increase of myeloperoxidase-positive neutrophils in the intestine from wild-type and transgenic mice after the DSS treatment. Furthermore, the increase of neutrophils under stimulation with DSS was confirmed quantitatively by measuring specific tissue myeloperoxidase activities. It was significantly greater in DSS-treated MIP-2 transgenic mice than in wild-type mice in both the small intestine and colon. These results suggest that the inflammatory effects of DSS on both small intestine and colon are enhanced by MIP-2 secreted by epithelial cells in the transgenic mice. In conclusion, intestinal epithelial cells can act in concert with other inflammatory stimuli in maintaining inflammation.

Effects of oral administration of bifidobacterium breve on fecal lactic acid and short-chain fatty acids in low birth weight infants.

Objectives:Short-chain fatty acids (SCFAs) are known to provide energy to colonocytes, whereas overproduction of SCFAs can cause mucosal injury in premature infants. Our objective was to investigate the effects of the oral administration of Bifidobacterium breve M-16V (B breve) on fecal lactic acid and SCFAs in low birth weight (LBW) infants. Patients and Methods:Fecal lactic, acetic, propionic, and butyric acids from 66 premature infants were analyzed by high-performance liquid chromatography at 0, 2, and 4 weeks after birth. The subjects included 22 extremely LBW (ELBW, <1000 g), 22 very LBW (VLBW, <1500 g), and 22 LBW (<2500 g) infants. The infants were divided into two groups: those with and those without B. breve supplementation. Results:In the control groups, fecal acetic acid and total SCFA concentrations were significantly increased at 2 weeks in the VLBW and LBW infants (P < 0.05) and at 4 weeks in the ELBW, VLBW, and LBW infants (P < 0.01 for each) compared with those at week 0. Fecal lactic acid concentrations showed a similar pattern during follow-up, but the differences were not significant. Four weeks after B breve administration, the fecal butyric acid concentrations were significantly decreased in the ELBW and VLBW infants (P < 0.05 each), and the ratio of the acetic acid concentrations to the total SCFAs was significantly increased compared with those of the control groups in the ELBW (P < 0.05), VLBW (P < 0.05), and LBW infants (P < 0.01). Conclusions:Oral administration of B breve reduces the production of butyric acid, which may be helpful in protecting LBW infants from digestive diseases such as necrotizing enterocolitis.

Antigen-specific T-cell responses in patients with non-IgE-mediated gastrointestinal food allergy are predominantly skewed to TH2

Age (mo) 12 38.0 (26.5-60.0) 65 2.0 (1.0-4.0) Male/female sex 12 7/5 65 40/25 Day of onset 12 — 65 32.5 (7.0-115.5) Symptoms at onset Vomiting 12 0% (0/12) 65 53.8% (35/65) Bloody stool 12 0% (0/12) 65 47.7% (31/65) Diarrhea 12 0% (0/12) 65 47.7% (31/65) Failure to thrive 12 0% (0/12) 65 38.4% (22/65) Lethargy 12 0% (0/12) 65 38.4% (22/65) Fever 12 0% (0/12) 65 18.5% (12/65) Eczema 12 100% (12/12) 65 7.7% (5/65) Wheeze 12 33.3% (3/12) 65 0% (0/65) Laboratory data Milk-specific IgE (IU/mL) 12 56.95 (11.74-90.8) 65 <0.34 (<0.34)

Studies of anti-inflammatory effects of Rooibos tea in rats.

Background:  Rooibos tea is known to be caffeine free with abundant flavonoids. Aspalathin and nothofagin, the main flavonoids contained in Rooibos tea, have stronger anti‐oxidative activity than other flavonoids.

Increased mucosal expression of GATA-3 and STAT-4 in pediatric ulcerative colitis

Background:  Serum pro‐inflammatory cytokine levels are frequently elevated in the acute phase of pediatric inflammatory bowel disease (IBD). Because the role of pro‐inflammatory cytokine in the acute phase of pediatric IBD has not been well investigated, the serum levels of pro‐inflammatory cytokines and the expression of Th1 and Th2 signaling molecules in mucosa from the acute phase of pediatric IBD were examined.