Taku Iwamoto

Dietary flavonoid naringenin induces regulatory T cells via an aryl hydrocarbon receptor mediated pathway.

The aryl hydrocarbon receptor (AhR), a transcription factor mediating xenobiotic detoxification, plays a considerable role in regulatory T cell (Treg) induction. Tregs regulate the immune system, thus suppressing allergies and autoimmune diseases. This study aims to identify new types of antiallergic dietary factors, with focus on the flavonoids with potential AhR agonistic activity. Among 25 dietary flavonoid samples tested using a reporter assay, 8 showed marked induction of AhR-dependent transcriptional activity. The subsequent T cell proliferation suppression assay identified naringenin as the only sample capable of stimulating Treg induction; notably, this induction was eliminated by cotreatment with AhR antagonists. Indeed, naringenin induced CD4(+)Foxp3(+) Tregs, irrespective of the presence of the transforming growth factor-β (TGF-β), indicating that the conventional TGF-β-dependent signaling pathway might not be involved.

Effects of Chondroitin Sulfate and Its Oligosaccharides on Toll-Like Receptor-Mediated IL-6 Secretion by Macrophage-Like J774.1 Cells

The effects of two types of chondroitin sulphate (CS), CS-A and CS-C, their oligosaccharides (oligo-CSs), and disaccharides (Di-CSs) on toll-like receptor (TLR)-mediated secretion of interleukin (IL)-6 were compared using macrophage-like cell line J774.1. IL-6 secretion in the J774.1 cells was markedly increased by Pam3CS4, LPS, and CpG, the ligands to TLR1/2, 4, and 9 respectively. Among these three ligands, CpG-induced IL-6 was most clearly suppressed by CSs and their digests. Suppression of IL-6 secretion by smaller sized CS-A was stronger than that by intact CS-A, whereas no such size-dependent suppression was apparent for CS-C. Di-4S, the disaccharide unit of the CS-A digest, also showed much stronger suppression than Di-6S, the disaccharide unit of the CS-C digest, and the non-sulfated disaccharide unit, Di-0S. The suppressing activity of oligo-CSs, particularly Di-CSs, against TLR-mediated inflammation was dependent on the CS structure, including the sulfation site.

Establishment of Intestinal Epithelial Cell Lines from Adult Mouse Small and Large Intestinal Crypts

Small and large intestinal epithelial cell (IEC) lines were established from adult murine intestinal crypts. Both established small and large IECs line (named aMoS7 and aMoC1 respectively) expressed epithelial markers. Similarly to IECs isolated from adult mouse intestines, the expression of major histocompatibility complex (MHC) class II molecules was induced by interferon-γ-treatment in both established cell lines. This expression of MHC class II molecules was higher in small intestinal aMoS7 cells than in large intestinal aMoC1 cells. Treatment with lipopolysaccharide and with ligands of Toll-like receptors 1, 2, 3, and 7 induced secretion of interleukin-6 from both adult IEC lines. These results suggest that the aMoS7 and aMoC1 cell lines can serve as useful tools in analyzing the immunological functions of IECs, especially in studying the IEC response to microbial components and its antigen presenting ability.

Effect of taurine on mRNA expression of thioredoxin interacting protein in Caco-2 cells

Taurine (2-aminoethanesulfonic acid), a sulfur-containing β-amino acid, plays an important role in several essential biological processes; although, the underlying mechanisms for these regulatory functions remain to be elucidated, especially at the genetic level. We investigated the effects of taurine on the gene expression profile in Caco-2 cells using DNA microarray. Taurine increased the mRNA expression of thioredoxin interacting protein (TXNIP), which is involved in various metabolisms and diseases. β-Alanine or γ-aminobutyric acid (GABA), which are structurally or functionally related to taurine, did not increase TXNIP mRNA expression. These suggest the expression of TXNIP mRNA is induced specifically by taurine. β-Alanine is also known to be a substrate of taurine transporter (TAUT) and competitively inhibits taurine uptake. Inhibition of taurine uptake by β-alanine eliminated the up-regulation of TXNIP, which suggests TAUT is involved in inducing TXNIP mRNA expression. The up-regulation of TXNIP mRNA expression by taurine was also observed at the protein level. Furthermore, taurine significantly increased TXNIP promoter activity. Our present study demonstrated the taurine-specific phenomenon of TXNIP up-regulation, which sheds light on the physiological function of taurine.

Disaccharide derived from chondroitin sulfate A suppressed CpG-induced IL-6 secretion in macrophage-like J774.1 cells

Interleukin (IL)-6 secretion from macrophage cells is known to be induced by toll-like receptor (TLR) 9 ligands, CpG (microbial DNA sequences containing unmethylated CpG dinucleotides). We have found, using macrophage-like J774.1 cells, that this induction was dramatically suppressed by a disaccharide derived from chondroitin sulfate A (Di-4S), but not by chondroitin sulfate A (CS-A) itself. The suppression of IL-6 secretion by Di-4S occurred at protein and mRNA expression levels. Di-4S inhibited the degradation of interleukin-1 receptor-associated kinase 1 (IRAK1) in the signaling pathway mediated by myeloid differentiation primary response gene (88) (MyD88) when stimulated by TLR9 activation. In addition to suppressing IRAK1 activation, interference with CpG-TLR9 interaction by Di-4S is also suggested to be one of the mechanisms. Oligosaccharides derived from chondroitin sulfates would be effective suppressing agents for the TLR9-mediated inflammation reaction.

Effects of oral administration of glucosylceramide on gene expression changes in hairless mouse skin: comparison of whole skin, epidermis, and dermis.

The beneficial effects of dietary glucosylceramide on the barrier function of the skin have been increasingly reported, but the entire mechanism has not been clarified. By DNA microarray, we investigated changes in gene expression in hairless mouse skin when a damage-inducing AD diet and a glucosylceramide diet (GluCer) were imposed. GluCer administration potentially suppressed the upregulation of six genes and the downregulation of four genes in the AD group. Examination of the epidermal and/or dermal expression of Npr3, Cyp17a1, Col1a1, S100a9, Sprr2f, Apol7a, Tppp, and Scd3 revealed responses of various parts of the skin to the diets. In normal hairless mice, GluCer administration induced an increase in the dermal expression of Cyp17a1 and the epidermal expression of Tppp, and a decrease in the epidermal expression of S100a9. Our results provide information on gene expression not only in whole skin but also in the epidermis and dermis that should prove useful in the search for the mechanisms underlying the effects of GluCer on damaged and normal skin.

Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4+ intestinal intraepithelial lymphocytes.

Small intestinal epithelial cells (sIECs) express major histocompatibility complex class II molecules even in a normal condition, and are known to function as antigen presenting cells (APCs) at least in vitro. These findings raised the possibility that sIECs play an important role in inducing immune responses against luminal antigens, especially those of intestinal intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs). We herein showed that antigenic stimulation with sIECs induced markedly greater secretion of interferon-gamma (IFN-γ) by CD4(+) IELs, but not interleukin (IL)-4, IL-10 and IL-17 although the proliferative response was prominently lower than that with T cell-depleted splenic APCs. In contrast, no enhanced IFN-γ secretion by CD4(+) LPLs and primed splenic CD4(+) T cells was observed when stimulated with sIECs. Taken together, these results suggest that sIECs uniquely activate CD4(+) IELs and induce remarkable IFN-γ secretion upon antigenic stimulation in vivo.

Adipofascial turnover perforator flap for dorsal hand reconstruction based on both the posterior interosseous artery and radial artery.

Alshawi AK, Scott TD. The crepe bandage as an alternative to the Esmarch bandage for upper limb exsanguination: a volumetric comparison study. J Hand Surg Br. 2004, 29: 183–4. Ballal MS, Emms N, O’Donoghue M, Redfern TR. RhysDavies exsanguinator: a haven for bacteria. J Hand Surg Eur. 2007, 32: 452–6. Blond L, Madsen JL. Exsanguination of the upper limb in healthy young volunteers. J Bone Joint Surg Br. 2002, 84: 489–91. Rhys-Davies NC, Stotter AT. The Rhys-Davies exsanguinator. Ann R Coll Surg Engl. 1985, 67: 193–5. Figure 2. (A) Crepe bandage roll placed in the palm. (B) Esmarch bandaging of clenched fist and forearm.

Effects of Food-Derived Collagen Peptides on the Expression of Keratin and Keratin-Associated Protein Genes in the Mouse Skin

Oral ingestion of collagen peptides (CP) has long been suggested to exert beneficial effects on the skin, but the molecular events induced by CP on the skin remain unclear. Here, we investigated the effects of oral CP administration on gene expression in hairless mouse skin and of prolyl-hydroxyproline (Pro-Hyp), a collagen-derived dipeptide, on gene expression in a coculture of mouse skin keratinocytes and fibroblasts. Using microarray analysis, we found that oral administration of CP to hairless mice for 6 weeks induced increased expression of Krtap and Krt genes in the skin. Annotation analysis using DAVID revealed that a group of the up-regulated genes, Gprc5d, Sprr2a1, Krt27 and Krtap16-7, is associated with the development of the epidermis and the hair cycle. In addition, the presence of Pro-Hyp (200 μM) induced an increase in the expression of Krtap16-7, Krtap15, Krtap14 and Krtap8-2 in keratinocytes in coculture, partially resembling the in vivo result. The Pro-Hyp-induced up-regulation of these genes was not observed when keratinocytes were cultured without fibroblasts, suggesting that the presence of fibroblasts is essential for the effects of Pro-Hyp. Our study presents new insights into the effects of CP on the skin, which might link to the hair cycle.

The role of non-enhanced angiography in toe tip transfer with small diameter pedicle

Toe tip transfer allows functional and esthetic reconstruction of the lost fingertip, but it is still uncommon because identification and dissection of donor and recipient veins can be challenging. Nonenhanced angiography (NEA) is a device that emits infrared light at a wavelength of 850 nm, which is exclusively absorbed by hemoglobin. The light penetrates the bones and other soft tissues, effectively visualizing veins in real time. The aim of this report is to present the experience on the preoperative use of nonenhanced angiography for visualization of donor and recipient veins in toe tip transfers in a series of patients.