Establishment of a novel mouse model of ulcerative colitis with concomitant cytomegalovirus infection: in vivo identification of cytomegalovirus persistent infected cells.

BACKGROUND: Human cytomegalovirus (HCMV) infection is considered to be an exacerbating factor in patients with ulcerative colitis (UC). However, the pathogenicity of HCMV in the exacerbation of UC remains unclear. The lack of a model mimicking UC with HCMV infection has posed a challenge for research into the pathogenic mechanism of HCMV in flare of UC. Therefore, the aim of our study was to establish a new mouse model of UC with HCMV infection. METHODS: We established latent murine CMV (MCMV) infection in T-cell receptor α knockout (TCR-α KO) mice at an early age by adjustment of viral dose. Next, we performed immunohistochemical analysis in various organs of infected adult TCR-α KO mice to prove the correlation between MCMV infection and development of colitis. We then assessed colitis histologically and cytokine expression in the colon of infected and uninfected TCR-α KO mice. Finally, the types of MCMV-infected cells in the inflamed colon were examined by immunohistochemical analysis. RESULTS: MCMV antigen-positive cells reappeared predominantly in the inflamed colon of TCR-α KO mice. Severe colitis developed in the infected TCR-α KO mice compared with uninfected mice, and Th1/Th17 and Th2 responses were strongly induced. MCMV-infected cells were mainly perivascular stromal cells including pericytes, expressing platelet-derived growth factor receptor-beta (PDGFR-ß) and CXC chemokine ligand 12 (CXCL12). CONCLUSIONS: In this study, we established, to our knowledge, the first mouse model of UC with HCMV infection. This model is an excellent tool for clarifying the detailed pathogenicity of HCMV in the exacerbation of UC and developing new treatment strategy for active UC with HCMV infection.

Heparan sulfate on intestinal epithelial cells plays a critical role in intestinal crypt homeostasis via Wnt/ß-catenin signaling.

Heparan sulfate (HS), a constituent of HS proteoglycans (HSPGs), is a linear polysaccharide present on the cell surface. HSPGs modulate functions of several growth factors and signaling molecules. We examined whether small intestinal epithelial HS plays some roles in crypt homeostasis using intestinal epithelium cell (IEC)-specific HS-deficient C57Bl/6 mice. Survival rate after total body irradiation was significantly reduced in HS-deficient mice due to profound intestinal injury. HS-deficient IECs exhibited Wnt/ß-catenin pathway disruption, decreased levels of ß-catenin nuclear localization, and reduced expression of Wnt target genes, including Lgr5 during crypt regeneration. Moreover, epithelial HS increased Wnt binding affinity of IECs, promoted phosphorylation of Wnt coreceptor LRP6, and enhanced Wnt/ß-catenin signaling following ex vivo stimulation with Wnt3a, whereas activation of canonical Wnt signaling following direct inhibition of glycogen synthase kinase-3ß by lithium chloride was similar between HS-deficient and wild-type mice. Thus HS influences the binding affinity of IECs to Wnt, thereby promoting activation of canonical Wnt signaling and facilitating regeneration of small intestinal crypts after epithelial injury.

Prior use of immunomodulatory drugs improves the clinical outcome of endoscopic balloon dilation for intestinal stricture in patients with Crohn's disease.

BACKGROUND: Endoscopic balloon dilation is a promising procedure to improve symptoms of intestinal stricture in patients with Crohn's disease (CD). However, the long-term efficacy of endoscopic balloon dilation combined with immunomodulatory drugs remains unclear. The aim of the present study is to investigate whether prior use of immunomodulatory drugs affects the clinical outcome of endoscopic balloon dilation for intestinal stricture in CD. PATIENTS AND METHODS: Between January 2004 and December 2011, 83 dilations were carried out in 25 patients with CD. Median follow-up period was 46 months. Patients were categorized into two groups based on their medications at the first endoscopic balloon dilation: early immunomodulatory drug-induction group (early IM-induction group) in which patients were already treated with immunomodulatory drugs before the dilation; and post-immunomodulatory drug-induction group (post-IM-induction group) in which patients were not yet treated withimmunomodulatory drugs before dilation. We compared the long-term cumulative non-surgical rate and the mean number of dilation procedures per patient between early and post-IM-induction groups to clarify the influence of prior use of immunomodulatory drugs on the clinical outcome of endoscopic balloon dilation. RESULTS: There was a significant difference in the mean number of dilation procedures per patient between the early IM-induction and post-IM-induction groups (P = 0.04), although no significant difference in the cumulative non-surgical rate was observed between the two groups (P = 0.14). CONCLUSION: Prior use of immunomodulatory drugs may improve the clinical outcome of endoscopic balloon dilation for intestinal stricture in CD.

Effect and safety of granulocyte-monocyte adsorption apheresis for patients with ulcerative colitis positive for cytomegalovirus in comparison with immunosuppressants.

BACKGROUND: Cytomegalovirus (CMV) infection exacerbates ulcerative colitis (UC) refractory to immunosuppressive therapies (IMT). However, the underlying UC remained active in some UC patients, despite the fact that CMV-DNA in colonic mucosa became negative after antiviral therapy. Therefore, new therapeutic strategies for UC patients concomitant with CMV infection in mucosa are required. AIMS: The aim of this study was to evaluate the effect and safety of granulocyte-monocyte adsorption apheresis (GMA) in UC patients positive for CMV infection after antiviral therapy. METHODS: From October 2003 to December 2008, 64 patients with UC refractory to IMT, including steroids and immunomodulators, were enrolled in this retrospective, observational, multicenter study, which was reviewed and approved by the Institutional Review Board of Kyoto University. CMV infection was investigated by 3 methods (histologic examination, CMV antigenemia, and polymerase chain reaction). We investigated the clinical outcomes of GMA and IMT after 2 weeks of treatment with ganciclovir. RESULTS: Thirty-one (48.4%) of 64 patients with UC refractory to IMT were positive for CMV. Of the 31 patients, 4 (12.9%) underwent colectomy. Twenty-seven patients (87.1%) underwent antiviral therapy. Of those 27 patients, 7 achieved remission following antiviral therapy alone. Of the remaining 20 patients who did not achieve remission despite the disappearance of CMV-DNA, 11 and 9 patients were treated with additional GMA (GMA group) and IMT (IMT group), respectively. Of 11 patients (GMA group), 9 achieved remission and 2 underwent colectomy. Out of the remaining 9 patients (IMT group), 4 achieved remission and 5 underwent colectomy. CMV-DNA was not detected in 11 patients after GMA, but it was detected again in all 5 patients of the IMT group who underwent colectomy. The total colectomy rate in UC patients positive for CMV was 35.5% (11/31). In addition, colectomy-free survival in the CMV relapse (+) group was estimated to be 12.9% at 65 months, while that in the CMV relapse (-) group was estimated to be 100% at 60 months. CONCLUSION: The colectomy ratio tends to be high in refractory UC patients with recurrent CMV reactivation or infection. Therefore, GMA might be a safe and effective treatment for UC patients positive for CMV because it does not induce CMV reactivation.

Role of heat shock protein 47 in intestinal fibrosis of experimental colitis.

BACKGROUND AND AIMS: Intestinal fibrosis is a clinically important issue of inflammatory bowel disease (IBD). It is unclear whether or not heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, plays a critical role in intestinal fibrosis. The aim of this study is to investigate the role of HSP47 in intestinal fibrosis of murine colitis. METHODS: HSP47 expression and localization were evaluated in interleukin-10 knockout (IL-10KO) and wild-type (WT, C57BL/6) mice by immunohistochemistry. Expression of HSP47 and transforming growth factor-ß1 (TGF-ß1) in colonic tissue was measured. In vitro studies were conducted in NIH/3T3 cells and primary culture of myofibroblasts separated from colonic tissue of IL-10KO (PMF KO) and WT mice (PMF WT) with stimulation of several cytokines. We evaluated the inhibitory effect of administration of small interfering RNA (siRNA) targeting HSP47 on intestinal fibrosis in IL-10KO mice in vivo. RESULTS: Immunohistochemistry revealed HSP47 positive cells were observed in the mesenchymal and submucosal area of both WT and IL-10 KO mice. Gene expressions of HSP47 and TGF-ß1 were significantly higher in IL-10KO mice than in WT mice and correlated with the severity of inflammation. In vitro experiments with NIH3T3 cells, TGF-ß1 only induced HSP47 gene expression. There was a significant difference of HSP47 gene expression between PMF KO and PMF WT. Administration of siRNA targeting HSP47 remarkably reduced collagen deposition in colonic tissue of IL-10KO mice. CONCLUSIONS: Our results indicate that HSP47 plays an essential role in intestinal fibrosis of IL-10KO mice, and may be a potential target for intestinal fibrosis associated with IBD.

[A case of jejunal adenocarcinoma with serum DUPAN-2 elevation].

A 50-year-old woman was admitted to our hospital because of abdominal pain and vomiting. Ileus with ulcerated jejunal tumor was diagnosed and biopsy revealed adenocarcinoma. Because her serum level of DUPAN-2 was high, she was examined by PET scan, which revealed that she had a left ovarian mass in addition to the jejunal tumor. Surgical resection was performed: both tumors were adenocarcinoma, but the ovarian tumor was considered to be metastatic clinically and histologically. Immunostaining for DUPAN-2 was positive in the both tumors. The serum level of DUPAN-2 returned to normal after the surgery, and has been within normal limits for about 3 years without any additional therapy. This case shows a possible relation between small bowel adenocarcinoma and DUPAN-2.

Immunosuppressive effects of tacrolimus on macrophages ameliorate experimental colitis.

BACKGROUND: Tacrolimus is a novel immunomodulator for inflammatory bowel diseases. Immunosuppressive effects of tacrolimus on T cells are well known; however, the effects of tacrolimus on macrophages remain unclear. The aim of this study was to investigate the effects of tacrolimus on activated macrophages and to examine its efficacy in murine colitis models. METHODS: Proinflammatory cytokine production from lipopolysaccharide (LPS)-stimulated peritoneal macrophages of IL-10-knockout (KO) mice with and without tacrolimus was measured. We investigated the effects of tacrolimus on nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and caspase activation in macrophages and the induction of apoptosis in macrophages in vitro and examined the in vivo apoptotic effect of tacrolimus on colonic macrophages in IL-10-KO mice. We evaluated the effect of the rectal administration of tacrolimus on colonic inflammation in IL-10-KO mice and dextran sulfate sodium (DSS)-induced colitis in CB.17/SCID mice. RESULTS: Proinflammatory cytokine production from tacrolimus-treated macrophages was significantly lower than that from untreated cells. Tacrolimus suppressed LPS-induced activation of both NF-κB and MAPK in macrophages and induced apoptosis of macrophages via activation of caspases 3 and 9. Rectal administration of tacrolimus evoked apoptosis of colonic macrophages in IL-10-KO mice. Moreover, the rectal administration of tacrolimus ameliorated colitis in IL-10-KO mice and DSS-induced colitis in CB.17/SCID mice. Gene expression of inflammatory cytokines in colonic mucosa was significantly lower in tacrolimus-treated mice than in untreated mice. CONCLUSIONS: Tacrolimus suppresses the function of activated macrophages and promotes their apoptosis, which may lead to the amelioration of colonic inflammation.

Spontaneous rupture of liver plasmacytoma mimicking hepatocellular carcinoma.

Extramedullary plasmacytoma of the liver is rare. Here, we report a case presenting with rupture of extramedullary plasmacytoma of the liver. She had a past history of multiple myeloma with IgA lambda type. Her serum was positive for hepatitis C virus infection and exhibited elevated levels of serum protein induced by vitamin K absence or antagonist-II. She was initially diagnosed as rupture of hepatocellular carcinoma (HCC) and then treated with transarterial chemoembolization (TACE) since bloody ascites and formation of hematoma were seen around hyper-vascular liver tumors on computed tomography. However, the clinical course of this case after TACE was atypical for HCC rupture, as shown by the development of a huge intra-abdominal abscess extending from the liver tumor. Immuno-histochemical analysis of the tumor biopsy specimen revealed massive infiltration of plasma cells expressing IgA and lambda chain. To our knowledge, this is the first case of rupture of extramedullary liver plasmacytoma.

Combination of Endoscopic Resection and Heat Ablation Is a Promising Endoscopic Therapy for Adenoma-Like Dysplastic Lesion in Chronic Ulcerative Colitis.

In January 2007, a 74-year-old male was admitted to our hospital for treatment of an adenoma-like dysplastic lesion (ALM). He had a four-year history of ulcerative colitis. Endoscopic findings revealed that a protruded lesion with an approximate size of 3 cm at the splenic flexure was surrounded by pseudopolyps. Lifting of the tumor was poor despite injection of normal saline around it. Therefore, the combination of endoscopic resection and heat ablation therapy with argon plasma coagulation was performed. Histopathological examination of the resected specimen showed tubular adenoma with high-grade atypia. Endoscopic examination 15 months after this treatment revealed no occurrence of ALM. Whether or not there is a possibility of local recurrence after ablation therapy in addition to endoscopic resection performed in this case remains unclear. However, this endoscopic therapy is a promising option for ALM in chronic ulcerative colitis.