Ryuyo Suzuki

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.

Circadian clock gene Period2 regulates a time-of-day–dependent variation in cutaneous anaphylactic reaction

BACKGROUND IgE-mediated immediate-type skin reaction shows a diurnal rhythm, although the precise mechanisms remain uncertain. Period2 (Per2) is a key circadian gene that is essential for endogenous clockworks in mammals. OBJECTIVE This study investigated whether Per2 regulates a time-of-day-dependent variation in IgE-mediated immediate-type skin reaction. METHODS The kinetics of a passive cutaneous anaphylactic reaction were compared between wild-type mice and mice with a loss-of-function mutation of Per2 (mPer2(m/m) mice). The effects of adrenalectomy, aging, and dexamethasone on the kinetics of a passive cutaneous anaphylactic reaction were also examined. In addition, the extent of IgE-mediated degranulation in bone marrow-derived mast cells (BMMCs) was compared between wild-type and mPer2(m/m) mice. RESULTS A time-of-day-dependent variation in a passive cutaneous anaphylactic reaction observed in wild-type mice was absent in mPer2(m/m) mice and in adrenalectomized and aged mice associated with the loss of rhythmic secretion of corticosterone. In addition, mPer2(m/m) mice showed decreased sensitivity to the inhibitory effects of dexamethasone on the passive cutaneous anaphylactic reactions. IgE-mediated degranulation in BMMCs was comparable between wild-type and mPer2(m/m) mice, but Per2 mutation decreased sensitivity to the inhibitory effects of dexamethasone on IgE-mediated degranulation in BMMCs. CONCLUSION A circadian oscillator, Per2, regulates a time-of-day-dependent variation in a passive cutaneous anaphylactic reaction in mice. Per2 may do so by controlling the rhythmic secretion of glucocorticoid from adrenal glands and/or by gating the glucocorticoid responses of mast cells to certain times of the day (possibly when Per2 levels are high in mast cells).

Usefulness of nonbreath-hold 1-shot magnetic resonance cholangiopancreatography for the evaluation of choledochal cyst in children.

Objective: The aim of this study was to clarify the usefulness of magnetic resonance cholangiopancreatography (MRCP) for the evaluation of choledochal cyst in children. Subjects and methods: MRCP was performed preoperatively in 33 patients. The MRCP findings were compared with those of endoscopic retrograde cholangiopancreatography or intraoperative cholangiopancreatography. Results: In all 33 patients, MRCP could detect choledochal cyst. The detection rate of a cyst in the main pancreatic duct was 62.2%, of abnormal union of the pancreaticobiliary junction (AUPBJ) was 53.3%, of dilatation or abnormalities of the main pancreatic duct was 75.0% and of a protein plug or stone was 76.9%. In patients under 2 years of age (group A), these findings were significantly lower than those of patients above 2 years of age (group B) [main pancreatic duct: 16.6% (1/6) vs 73.1% (19/26), P < 0.01; AUPBJ: 0.0% (0/6) vs 66.7% (16/24), P < 0.05; and protein plug or stone: 0.0% (0/2) vs 90.9% (10/11), P < 0.05]. The detection rate of AUPBJ in the patients with fusiform dilatation was superior to that of those with cystic dilatation [70% (14/20) vs 20% (2/10), P < 0.05]. In the patients with fusiform dilatation, the detection rate in group A was significantly lower than that in group B [0.0% (0/3) vs 82.4% (14/17), P < 0.01]; however, there was no significant difference between the 2 groups in the detection of cystic dilatation. Conclusion: In patients older than 2 years, MRCP should be the first-choice method for confirming the diagnosis and for ensuring accurate visualization of the pancreaticobiliary system.

Critical role of transcription factor PU.1 in the expression of CD80 and CD86 on dendritic cells

In this study, we investigated the role of a transcription factor, PU.1, in the regulation of CD80 and CD86 expression in dendritic cells (DCs). A chromatin immunoprecipitation assay revealed that PU.1 is constitutively bound to the CD80 and CD86 promoters in bone marrow-derived DCs. In addition, co-expression of PU.1 resulted in the transactivation of the CD80 and CD86 promoters in a reporter assay. The binding of PU.1 to cis-enhancing regions was confirmed by electromobility gel-shift assay. As expected, inhibition of PU.1 expression by short interfering RNA (siRNA) in bone marrow-derived DCs resulted in marked down-regulation of CD80 and CD86 expression. Moreover, overexpression of PU.1 in murine bone marrow-derived lineage-negative cells induced the expression of CD80 and CD86 in the absence of monocyte/DC-related growth factors and/or cytokines. Based on these results, we conclude that PU.1 is a critical factor for the expression of CD80 and CD86. We also found that subcutaneous injection of PU.1 siRNA or topical application of a cream-emulsified PU.1 siRNA efficiently inhibited murine contact hypersensitivity. Our results suggest that PU.1 is a potential target for the treatment of immune-related diseases.

GATA2 Is a Critical Transactivator for the Human IL1RL1/ST2 Promoter in Mast Cells/Basophils OPPOSING ROLES FOR GATA2 and GATA1 IN HUMAN IL1RL1/ST2 GENE EXPRESSION

Background: The IL1RL1/ST2 gene encodes the receptor for IL-33, which is important for Th2 responses. Results: GATA2 knockdown reduced the expression of human IL1RL1/ST2 in KU812 and LAD2 cells and in human primary peripheral basophils. Conclusion: GATA2, but not GATA1, is a critical transcription factor for expression of human IL1RL1/ST2 in mast cell/basophil lineages. Significance: GATA2 and GATA1 exhibit distinctive roles in the expression of human IL1RL1/ST2. The IL1RL1/ST2 gene encodes a receptor for IL-33. Signaling from IL1RL1/ST2 induced by IL-33 binding was recently identified as a modulator of the Th2 response. The target cells for IL-33 are restricted in some hematopoietic lineages, including mast cells, basophils, eosinophils, Th2 cells, natural killer cells, and dendritic cells. To clarify the molecular mechanisms of cell type-specific IL1RL1/ST2 expression in mast cells and basophils, transcriptional regulation of the human IL1RL1/ST2 promoter was investigated using the mast cell line LAD2 and the basophilic cell line KU812. Reporter assays suggested that two GATA motifs just upstream of the transcription start site in the ST2 promoter are critical for transcriptional activity. These two GATA motifs possess the capacity to bind GATA1 and GATA2 in EMSA. ChIP assay showed that GATA2, but not GATA1, bound to the ST2 promoter in LAD2 cells and that histone H3 at the ST2 promoter was acetylated in LAD2 cells, whereas binding of GATA1 and GATA2 to the ST2 promoter was detected in KU812 cells. Knockdown of GATA2 mRNA by siRNA reduced ST2 mRNA levels in KU812 and LAD2 cells and ST2 protein levels in LAD2 cells; in contrast, GATA1 siRNA transfection up-regulated ST2 mRNA levels in KU812 cells. The ST2 promoter was transactivated by GATA2 and repressed by GATA1 in coexpression analysis. When these siRNAs were introduced into human peripheral blood basophils, GATA2 siRNA reduced ST2 mRNA, whereas GATA1 siRNA up-regulated ST2 mRNA. These results indicate that GATA2 and GATA1 positively and negatively control human ST2 gene transcription, respectively.

Magnetic resonance cholangiopancreatography in assessing the cause of acute pancreatitis in children.

Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive method of obtaining images of the pancreaticobiliary tract. Recent advances in MR technology and image quality have made it easy to diagnose structural abnormalities of the pancreaticobiliary tract (SAPBT) in children. To examine the usefulness of MRCP in assessing the cause of acute pancreatitis in children, we performed MRCP in 16 patients with acute pancreatitis. The study population was divided into two groups according to the cause of acute pancreatitis as follows: group 1 consisted of seven patients sonographically diagnosed with choledochal cysts; and group 2 consisted of nine patients with no obvious cause of acute pancreatitis. Non–breath-hold MRCP using the half-Fourier, single-shot, fast spin-echo imaging method was performed within 7 days after the onset of pancreatitis. Abnormal union of the pancreaticobiliary junction was detected in six of seven group 1 patients and in one of nine group 2 patients. Pancreatic divisum was detected in one patient of group 1, but could not be confirmed in one patient of group 2. Dilatation of the main pancreatic duct was detected in one patient of group 1 and in three patients of group 2. Our results suggest that MRCP is a useful, noninvasive method of identifying and ruling out SAPBT as a cause of acute pancreatitis in children with early-stage pancreatitis.

Effects of Bifidobacterium breve on inflammatory gene expression in neonatal and weaning rat intestine

Introduction:To examine the immune-modulatory effects of probiotics during early infancy, Bifidobacterium breve M-16V (B. breve) was administered to rat pups during the newborn or weaning period, and the expression of inflammatory genes was investigated using a cDNA microarray and real-time PCR.Results:After B. breve administration, significant increases in the numbers of Bifidobacterium in both the cecum and colon were confirmed during the newborn period. The numbers of upregulated and downregulated genes were greater during the weaning period than in the newborn period and were greatest in the colon, with fewer genes altered in the small intestine and the fewest in the spleen. The expression of inflammation-related genes, including lipoprotein lipase (Lpl), glutathione peroxidase 2 (Gpx2), and lipopolysaccharide-binding protein (Lbp), was significantly reduced in the colon during the newborn period. In weaning rat pups, the expression of CD3d, a cell surface receptor–linked signaling molecule, was significantly enhanced in the colon; however, the expression of co-stimulatory molecules was not enhanced.Discussion:Our findings support a possible role for B. breve in mediating anti-inflammatory and antiallergic reactions by modulating the expression of inflammatory molecules during the newborn period and by regulating the expression of co-stimulatory molecules during the weaning period.Methods:Gene expression in the intestine was investigated after feeding 5×108 cfu of B. breve every day to the F344/Du rat from days 1 to 14 (newborn group) and from days 21 to 34 (weaning group). mRNA was extracted from intestine, and the expression of inflammatory gene was analyzed by microarray and real-time PCR.

Lissencephaly with marked ventricular dilation, agenesis of corpus callosum, and cerebellar hypoplasia caused by TUBA1A mutation

We described the clinical course and pathological findings in a child with TUBA1A mutation. MRI revealed marked ventricular dilation with thin cortex, poorly differentiated basal ganglia, agenesis of corpus callosum, cerebellar hypoplasia with preserved vermis at 2 months of age. No gain of developmental milestones was observed until she died with respiratory failure at 23 months of age. A de novo missense mutation of c.1096G>A (G366R) was identified in TUBA1A gene. Pathological findings included a lack in lamination in the cerebral cortex, absent corpus callosum without Probst bundle, blurred demarcation among the striatum, internal capsule and globus pallidus in association with irregular running of myelinated fibers, cerebellar hypoplasia with irregular undulation in the dentate nucleus and inferior olivary nucleus, absent olfactory bulbs and tracts, and pyramidal tract hypoplasia. These findings are consistent with previous reports and will be a clue to diagnosis of TUBA1A mutation.

Microarray analysis of mucosal biopsy specimens in neonates with rectal bleeding: is it really an allergic disease?

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Monitoring 6-thioguanine nucleotide concentrations in Japanese children and adolescents with inflammatory bowel disease.

Background and Aim:  6‐Mercaptopurine (6‐MP) and azathioprine (AZA) are widely used as maintenance therapy in children with inflammatory bowel disease (IBD). However, proper 6‐thioguanine nucleotide (6‐TGN) concentrations in Japanese children with IBD have not been reported.