[Show abstract][Hide abstract] ABSTRACT: Although intestinal microbiota are essential for the development of T cell-mediated colitis, it remains undetermined whether they enhance or suppress the chronic extraintestinal inflammation that often complicates inflammatory bowel diseases. In this study, we investigate the role of intestinal microbiota in the development of colitis and extraintestinal manifestations in a mouse model in which colitis was induced in SCID mice by adoptive transfer of CD4(+)CD45RB(high) T cells. Under specific pathogen-free conditions, these mice developed both colitis and extraintestinal interstitial pneumonia, whereas mice given a mixture of antibiotics did not develop colitis, but, surprisingly, developed Th1/Th17-mediated IP. Irrespective of antibiotic treatment, cotransfer of CD4(+)CD25(+) regulatory T cells suppressed the development of pneumonitis and colitis, with all local CD4(+)CD45RB(high) T cell-derived cells converted to CD44(high)CD62L(-)IL-7Rα(high) effector-memory T cells. Retransfer of CD4(+) effector-memory T cells from the lungs of antibiotic-treated mice with IP not only induced IP in both antibiotic-treated and -untreated recipients but also induced colitis in the untreated recipients. In summary, we have established a unique model of Th1/Th17-mediated IP in microbiota-free and antibiotic-treated mice. This model may be valuable in investigating the immunological mechanisms underlying extraintestinal disorders in patients with inflammatory bowel disease.
No preview · Article · May 2013 · The Journal of Immunology
[Show abstract][Hide abstract] ABSTRACT: The transcription factor Atonal homolog 1 (Atoh1) plays crucial roles in the differentiation of intestinal epithelium cells. Although we have reported that the Atoh1 protein was degraded in colon cancer by aberrant Wnt signaling, a recent study has indicated that the Atoh1 protein is expressed in mucinous colon cancer (MC) and signet ring cell carcinoma (SRCC). However, the roles of the Atoh1 protein in MC are unknown. To mimic MC, a mutated Atoh1 protein was stably expressed in undifferentiated colon cancer cells. Microarray analysis revealed the acquisition of not only the differentiated cell form, but also malignant potential by Atoh1 protein stabilization. In particular, Atoh1 enhanced Wnt signaling, resulting in the induction of Lgr5 as a representative stem cell marker with the enrichment of cancer stem cells. Moreover, the fluorescent ubiquitination-based cell cycle indicator system with time-lapse live imaging demonstrated cell cycle arrest in the G0/G1 phase by Atoh1 protein stabilization. In conclusion, the Atoh1 protein regulates malignant potential rather than the differentiation phenotype of MC, suggesting the mechanism by which MC and SRCC are more malignant than non-mucinous adenocarcinoma.
Full-text · Article · Jan 2013 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract] ABSTRACT: Objective
Interleukin (IL)-7 is mainly produced in bone marrow (BM) that forms the niche for B cells. We previously demonstrated that BM also retains pathogenic memory CD4 T cells in murine models of inflammatory bowel disease (IBD). However, it remains unknown whether BM-derived IL-7 is sufficient for the development of IBD and which cells form the niche for colitogenic memory CD4 T cells in BM.
To address these questions, we developed mice in which IL-7 expression was specific for BM, and identified colitis-associated IL-7-expressing mesenchymal stem cells (MSC) in the BM.
IL-7–/–×RAG-1–/– mice injected with BM cells from IL-7+/+×RAG-1–/– mice, but not from IL-7–/–×RAG-1–/– mice, expressed IL-7 in BM, but not in their colon, and developed colitis when injected with CD4+CD45RBhigh T cells. Cultured BM MSC stably expressed a higher level of IL-7 than that of primary BM cells. IL-7-sufficient, but not IL-7-deficient, BM MSC supported upregulation of Bcl-2 in, and homeostatic proliferation of, colitogenic memory CD4 T cells in vitro. Notably, IL-7–/–×RAG-1–/– mice transplanted with IL-7-sufficient, but not IL-7-deficient, BM MSC expressed IL-7 in BM, but not in their colon, and developed colitis when transplanted with CD4+CD45RBhigh T cells.
We demonstrate for the first time that BM MSC are a major source of IL-7 and play a pathological role in IBD by forming the niche for colitogenic CD4 memory T cells in BM.
[Show abstract][Hide abstract] ABSTRACT: Applications of double-balloon endoscopy (DBE) have expanded widely to areas beyond small-intestine endoscopy. Two endoscopists are required for standard insertion, but it is preferable to have DBE carried out by one endoscopist to optimize control of the procedure and because of human resources issues. We previously reported on the Single-Operator Method, but here we describe newly modified insertion techniques that facilitate and enhance the performance of DBE by a single endoscopist. Our new technique consists of Hooking Technique, Outside Support, Grasp Scope and Overtube, Continuous Overtube Infusion and Double-Overtube Method. These new techniques make it easier to carry out the Single-Operator Method.
No preview · Article · Nov 2012 · Digestive Endoscopy
[Show abstract][Hide abstract] ABSTRACT: Introduction
Inverted Meckel’s diverticulum has usually been misdiagnosed in the cases based on computed tomography images presented in the literature. The final diagnosis was made intra-operatively or by pathology reports after surgery. Despite this, preoperative diagnosis could be made successfully by using endoscopic ultrasound with double-balloon endoscopy prior to surgery.
A 60-year-old Japanese woman with severe anemia complained of several episodes of black stool over the preceding 2 years. Abdominal computed tomography showed a 3.0-cm low-density tumor in the ileum, suggesting a diagnosis of intestinal lipoma. Examination of the tumor by endoscopic ultrasound with double-balloon endoscopy revealed a hypo-echoic layer corresponding to the muscularis propria, and a hyper-echoic layer corresponding to the fat tissue. These findings, which suggested that the tumor included areas outside the intestinal serosa, are not typical for a lipoma, despite the existence of a hyper-echoic layer corresponding to fatty tissue. We then considered a diagnosis of inverted Meckel’s diverticulum.
Lipoma and inverted Meckel’s diverticulum are difficult to differentially diagnose by computed tomography. Polypectomy is the preferred therapeutic approach when a lipoma is present; however, polypectomy in a patient with Meckel’s diverticulum requires full-thickness resection. Situations where polypectomy is performed without preparing for full-thickness resection can be avoided by first making a precise diagnosis using double-balloon endoscopy and endoscopic ultrasound.
Full-text · Article · Sep 2012 · Journal of Medical Case Reports
[Show abstract][Hide abstract] ABSTRACT: We previously reported that IL-7(-/-)RAG(-/-) mice receiving naive T cells failed to induce colitis. Such abrogation of colitis may be associated with not only incomplete T cell maintenance due to the lack of IL-7, but also with the induction of colitogenic CD4(+) T cell apoptosis at an early stage of colitis development. Moreover, NK cells may be associated with the suppression of pathogenic T cells in vivo, and they may induce apoptosis of CD4(+) T cells. To further investigate these roles of NK cells, RAG(-/-) and IL-7(-/-)RAG(-/-) mice that had received naive T cells were depleted of NK cells using anti-asialo GM1 and anti-NK1.1 Abs. NK cell depletion at an early stage, but not at a later stage during colitogenic effector memory T cell (T(EM)) development, resulted in exacerbated colitis in recipient mice even in the absence of IL-7. Increased CD44(+)CD62L(-) T(EM) and unique CD44(-)CD62L(-) T cell subsets were observed in the T cell-reconstituted RAG(-/-) recipients when NK cells were depleted, although Fas, DR5, and IL-7R expressions in this subset differed from those in the CD44(+)CD62L(-) T(EM) subset. NK cell characteristics were the same in the presence or absence of IL-7 in vitro and in vivo. These results suggest that NK cells suppress colitis severity in T cell-reconstituted RAG(-/-) and IL-7(-/-)RAG(-/-) recipient mice through targeting of colitogenic CD4(+)CD44(+)CD62L(-) T(EM) and, possibly, of the newly observed CD4(+)CD44(-)CD62L(-) subset present at the early stage of T cell development.
Full-text · Article · Mar 2012 · The Journal of Immunology
[Show abstract][Hide abstract] ABSTRACT: Adult stem-cell therapy holds promise for the treatment of gastrointestinal diseases. Here we describe methods for long-term expansion of colonic stem cells positive for leucine-rich repeat containing G protein-coupled receptor 5 (Lgr5(+) cells) in culture. To test the transplantability of these cells, we reintroduced cultured GFP(+) colon organoids into superficially damaged mouse colon. The transplanted donor cells readily integrated into the mouse colon, covering the area that lacked epithelium as a result of the introduced damage in recipient mice. At 4 weeks after transplantation, the donor-derived cells constituted a single-layered epithelium, which formed self-renewing crypts that were functionally and histologically normal. Moreover, we observed long-term (>6 months) engraftment with transplantation of organoids derived from a single Lgr5(+) colon stem cell after extensive in vitro expansion. These data show the feasibility of colon stem-cell therapy based on the in vitro expansion of a single adult colonic stem cell.
[Show abstract][Hide abstract] ABSTRACT: P-glycoprotein (P-gp) is an efflux transporter that regulates bioavailability of orally administered drugs at the intestinal epithelium. To develop an in vitro experimental model that mimics P-gp-mediated intestinal drug transport in vivo, we employed normal intestinal epithelium three-dimensionally cultured. Physiological expression of P-gp mRNA and the expression of its protein at the apical membrane were observed in the small intestinal epithelium grown as cystic organoids. Rhodamine123 (Rh123), a substrate for P-gp, was actively transported in the basoapical direction and accumulated in the luminal space, while the epithelial integrity was kept intact. Furthermore, we were able to monitor the whole process of Rh123 transport and its inhibition by verapamil in real-time, from which kinetic parameters for Rh123 transport could be estimated by a mathematical modeling. The method here described to evaluate the dynamics of P-gp-mediated transport in primary intestinal epithelial cells would be instrumental in investigating the physiological function of P-gp and its inhibitors/inducers in vitro.
No preview · Article · Feb 2012 · Biochemical and Biophysical Research Communications
[Show abstract][Hide abstract] ABSTRACT: The transcription factor Atoh1/Hath1 plays crucial roles in the differentiation program of human intestinal epithelium cells (IECs). Although previous studies have indicated that the Notch signal suppresses the differentiation program of IEC, the mechanism by which it does so remains unknown. This study shows that the undifferentiated state is maintained by the suppression of the Hath1 gene in human intestine.
To assess the effect of Notch signaling, doxycycline-induced expression of Notch intracellular domain (NICD) and Hes1 cells were generated in LS174T. Hath1 gene expression was analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Hath1 promoter region targeted by HES1 was determined by both reporter analysis and ChIP assay. Expression of Hath1 protein in ulcerative colitis (UC) was examined by immunohistochemistry.
Hath1 mRNA expression was increased by Notch signal inhibition. However, Hath1 expression was suppressed by ectopic HES1 expression alone even under Notch signal inhibition. Suppression of the Hath1 gene by Hes1, which binds to the 5' promoter region of Hath1, resulted in suppression of the phenotypic gene expression for goblet cells. In UC, the cooperation of aberrant expression of HES1 and the disappearance of caudal type homeobox 2 (CDX2) caused Hath1 suppression, resulting in goblet cell depletion.
The present study suggests that Hes1 is essential for Hath1 gene suppression via Notch signaling. Moreover, the suppression of Hath1 is associated with goblet cell depletion in UC. Understanding the regulation of goblet cell depletion may lead to the development of new therapy for UC.
Full-text · Article · Nov 2011 · Inflammatory Bowel Diseases