Nobuhiro Ueno

Heat-killed body of lactobacillus brevis SBC8803 ameliorates intestinal injury in a murine model of colitis by enhancing the intestinal barrier function

Background: Probiotics have been clinically administered to improve intestinal damage in some intestinal inflammations. However, probiotic treatments are not always effective for these intestinal disorders because live bacteria must colonize and maintain their activity under unfavorable conditions in the intestinal lumen when displaying their functions. This study investigated the physiological functions of a heat‐killed body of a novel probiotic, Lactobacillus brevis SBC8803, on the protection of intestinal tissues, the regulation of cytokine production, the improvement of intestinal injury, and the survival rate of mice with dextran sodium sulfate (DSS)‐induced colitis. Methods: Heat shock protein (Hsp) induction and mitogen‐activated protein kinase (MAPK) phosphorylation in intestinal epithelia by heat‐killed L. brevis SBC8803 were examined by Western blotting. The barrier function of intestinal epithelia was measured with [3H]‐mannitol flux in the small intestine under oxidant stress. The effects of the bacteria on improving epithelial injury and cumulative survival rate were investigated with a DSS colitis model. Results: Heat‐killed L. brevis SBC8803 induced Hsps, phosphorylated p38 MAPK, regulated the expression of tumor necrosis factor alpha (TNF‐&agr;), interleukin (IL)‐1&bgr; and IL‐12, and improved the barrier function of intestinal epithelia under oxidant stress. The induction of Hsp and the protective effect were negated by p38 MAPK inhibitor. These functions relieve intestinal impairments and improve the survival rate in mice with lethal colitis. Conclusions: The administration of heat‐killed L. brevis SBC8803 helps to successfully maintain intestinal homeostasis, while also curing intestinal inflammation. A therapeutic strategy using heat‐killed bacteria is expected to be beneficial for human health even in conditions unsuitable for live probiotics because the heat‐killed body is able to exhibit its effects without the requirement of colonization. (Inflamm Bowel Dis 2011;)

The diagnostic accuracy of high-resolution endoscopy, autofluorescence imaging and narrow-band imaging for differentially diagnosing colon adenoma.

BACKGROUND AND STUDY AIMS Conventional colonoscopy can result in unnecessary biopsy or endoscopic resection due to its inability to distinguish adenomas from hyperplastic polyps. This study therefore evaluated the efficacy of high-resolution endoscopy (HRE), autofluorescence imaging (AFI), and narrow-band imaging (NBI) in discriminating colon adenoma from hyperplastic polyps. PATIENTS AND METHODS This was a prospective multicenter study in patients undergoing AFI and NBI examinations. HRE, AFI, and NBI images were classified into two groups based on morphological characteristics, the predominant color intensities, and the visibility of meshed capillary vessels, respectively. Each of the endoscopic photographs were independently evaluated by a single endoscopist. The images were then assessed by three specialists and three residents, the latter having performed < 500 colonoscopies and < 30 NBI and AFI examinations. Diagnostic test statistics were calculated to compare the accuracy in differentiating colon adenoma from hyperplastic polyps for each method. RESULTS A total of 183 patients were enrolled in the study and 339 adenomas and 85 hyperplastic polyps were identified. AFI and NBI could distinguish adenoma from hyperplastic polyps with an accuracy of 84.9 % and 88.4 %, respectively, whereas HRE exhibited an accuracy of 75.9 %. In the 358 lesions in which the AFI diagnosis was consistent with that of NBI, the accuracy, sensitivity, and specificity were high, at 91.9 %, 92.7 %, and 92.9 %, respectively. During the study comparing specialists and residents, AFI and NBI dramatically improved the diagnostic accuracy of residents from 69.1 % to 86.1 % and 84.7 %, respectively. CONCLUSIONS Both AFI and NBI are considered to be feasible tools that can discriminate colon adenoma from hyperplastic polyps, and their use may be particularly beneficial for less-experienced endoscopists.

microRNA-18a induces apoptosis in colon cancer cells via the autophagolysosomal degradation of oncogenic heterogeneous nuclear ribonucleoprotein A1.

It is well known that microRNAs (miRs) are abnormally expressed in various cancers and target the messenger RNAs (mRNAs) of cancer-associated genes. While (miRs) are abnormally expressed in various cancers, whether miRs directly target oncogenic proteins is unknown. The present study investigated the inhibitory effects of miR-18a on colon cancer progression, which was considered to be mediated through its direct binding and degradation of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1). An MTT assay and xenograft model demonstrated that the transfection of miR-18a induced apoptosis in SW620 cells. A binding assay revealed direct binding between miR-18a and hnRNP A1 in the cytoplasm of SW620 cells, which inhibited the oncogenic functions of hnRNP A1. A competitor RNA, which included the complementary sequence of the region of the miR-18a-hnRNP A1 binding site, repressed the effects of miR-18a on the induction of cancer cell apoptosis. In vitro single and in vivo double isotope assays demonstrated that miR-18a induced the degradation of hnRNP A1. An immunocytochemical study of hnRNP A1 and LC3-II and the inhibition of autophagy by 3-methyladenine and ATG7, p62 and BAG3 siRNA showed that miR-18a and hnRNP A1 formed a complex that was degraded through the autophagolysosomal pathway. This is the first report showing a novel function of a miR in the autophagolysosomal degradation of an oncogenic protein resulting from the creation of a complex consisting of the miR and a RNA-binding protein, which suppressed cancer progression.

Transnasal ultrathin endoscopy for placement of a long intestinal tube in patients with intestinal obstruction.

BACKGROUND The technical difficulties related to the insertion of a long intestinal tube into the jejunum under fluoroscopy present a considerable problem in patients with an intestinal obstruction. OBJECTIVE To evaluate the usefulness of endoscopic long intestinal-tube placement with the ultrathin esophagogastroduodenoscope (UT-EGD). DESIGN A prospective randomized clinical trial was conducted. PATIENTS Twenty-eight consecutive patients who presented with an intestinal obstruction were included in the study. INTERVENTION The UT-EGD was inserted nasally into at least the second portion of the duodenum or beyond. After a guidewire was introduced through the working channel, with fluoroscopic guidance, the UT-EGD itself was carefully removed with the guidewire left in place. Next, a hydrophilic intestinal tube was advanced over the guidewire into the jejunum, and then the guidewire was removed. MAIN OUTCOME MEASUREMENTS Primary end points are the total procedure time, the radiation exposure time, and the rate of complications, all compared with the conventional method. RESULTS The mean (+/-SD) total procedure time was 18.7 +/- 8.4 minutes for the UT-EGD method and 39.5 +/- 15.0 minutes for the conventional method, with a significant time difference between the 2 methods (P < .0005). The mean (+/-SD) radiation exposure time was also shorter with the UT-EGD method (11.1 +/- 6.0 minutes) than with the conventional method (30.3 +/- 13.7 minutes) (P < .0005). There were no complications, except for mild nasal bleeding with each method. CONCLUSIONS The UT-EGD method has definite advantages in the placement of a long intestinal tube for patients with an intestinal obstruction in comparison with the conventional method.

TU-100 (Daikenchuto) and Ginger Ameliorate Anti-CD3 Antibody Induced T Cell-Mediated Murine Enteritis: Microbe-Independent Effects Involving Akt and NF-κB Suppression

The Japanese traditional medicine daikenchuto (TU-100) has anti-inflammatory activities, but the mechanisms remain incompletely understood. TU-100 includes ginger, ginseng, and Japanese pepper, each component possessing bioactive properties. The effects of TU-100 and individual components were investigated in a model of intestinal T lymphocyte activation using anti-CD3 antibody. To determine contribution of intestinal bacteria, specific pathogen free (SPF) and germ free (GF) mice were used. TU-100 or its components were delivered by diet or by gavage. Anti-CD3 antibody increased jejunal accumulation of fluid, increased TNFα, and induced intestinal epithelial apoptosis in both SPF and GF mice, which was blocked by either TU-100 or ginger, but not by ginseng or Japanese pepper. TU-100 and ginger also blocked anti-CD3-stimulated Akt and NF-κB activation. A co-culture system of colonic Caco2BBE and Jurkat-1 cells was used to examine T-lymphocyte/epithelial cells interactions. Jurkat-1 cells were stimulated with anti-CD3 to produce TNFα that activates epithelial cell NF-κB. TU-100 and ginger blocked anti-CD3 antibody activation of Akt in Jurkat cells, decreasing their TNFα production. Additionally, TU-100 and ginger alone blocked direct TNFα stimulation of Caco2BBE cells and decreased activation of caspase-3 and polyADP ribose. The present studies demonstrate a new anti-inflammatory action of TU-100 that is microbe-independent and due to its ginger component.

Daikenchuto (TU-100) shapes gut microbiota architecture and increases the production of ginsenoside metabolite compound K

Many pharmaceutical agents not only require microbial metabolism for increased bioavailability and bioactivity, but also have direct effects on gut microbial assemblage and function. We examined the possibility that these actions are not mutually exclusive and may be mutually reinforcing in ways that enhance long‐term of these agents. Daikenchuto, TU‐100, is a traditional Japanese medicine containing ginseng. Conversion of the ginsenoside Rb1 (Rb1) to bioactive compound K (CK) requires bacterial metabolism. Diet‐incorporated TU‐100 was administered to mice over a period of several weeks. T‐RFLP and 454 pyrosequencing were performed to analyze the time‐dependent effects on fecal microbial membership. Fecal microbial capacity to metabolize Rb1 to CK was measured by adding TU‐100 or ginseng to stool samples to assess the generation of bioactive metabolites. Levels of metabolized TU‐100 components in plasma and in stool samples were measured by LC‐MS/MS. Cecal and stool short‐chain fatty acids were measured by GC‐MS. Dietary administration of TU‐100 for 28 days altered the gut microbiota, increasing several bacteria genera including members of Clostridia and Lactococcus lactis. Progressive capacity of microbiota to convert Rb1 to CK was observed over the 28 days administration of dietary TU‐100. Concomitantly with these changes, increases in all SCFA were observed in cecal contents and in acetate and butyrate content of the stool. Chronic consumption of dietary TU‐100 promotes changes in gut microbiota enhancing metabolic capacity of TU‐100 and increased bioavailability. We believe these findings have broad implications in optimizing the efficacy of natural compounds that depend on microbial bioconversion in general.

Collagenous colitis appeared after 6-year administration of lansoprazole

Collagenous colitis (CC) is one of the causes of undefined watery diarrhea, which is histologically accompanied by thickening of the subepithelial collagen layer. CC associated with lansoprazole normally occurs within several weeks after initial administration, but no case presenting after long-term administration of lansoprazole has yet been reported. A 77-year-old male with 6-year history of administration of lansoprazole complained of watery diarrhea and weight loss. Colonoscopy revealed disappearance of vascular networks and red spots in the sigmoid colon. Biopsy specimen showed erosion and collagen bands thickened, so the patient was diagnosed as CC. After lansoprazole discontinuation, the watery diarrhea disappeared and histological abnormalities improved.

Capsule endoscopy is a feasible procedure for identifying a Diphyllobothrium nihonkaiense infection and determining the indications for vermifuge treatment.

Diphyllobothrium is a member of Cestoda family, which is the largest parasite of humans. The diagnosis of diphyllobothriasis is based on the detection of eggs in the stool. Because the remainder of the scolex causes a relapse in diphyllobothriasis, the scolex must be completely discharged to cure the parasite infection. However, the scolex or forefront of the Diphyllobothrium is difficult to detect with gastroduodenoscopy and colonoscopy, because most Diphyllobothrium attach to the jejunal wall. In the present case, capsule endoscopy detected proglottids as well as forefront of the parasite at jejunum. Based on the results of capsule endoscopy, the patient underwent additional vermifuge (anthelminthic) treatment to cure the diphyllobothriasis and discharged a worm measuring 3 m in length with a scolex. Capsule endoscopy is a practical option to determine whether additional vermifuge treatment is required through the detection of the proglottids as well as a scolex or forefront of the parasite.

Soluble bioactive microbial mediators regulate proteasomal degradation and autophagy to protect against inflammation-induced stress

Bifidobacterium breve and other Gram-positive gut commensal microbes protect the gastrointestinal epithelium against inflammation-induced stress. However, the mechanisms whereby these bacteria accomplish this protection are poorly understood. In this study, we examined soluble factors derived from Bifidobacterium breve and their impact on the two major protein degradation systems within intestinal epithelial cells, proteasomes and autophagy. Conditioned media from gastrointestinal Gram-positive, but not Gram-negative, bacteria activated autophagy and increased expression of the autophagy proteins Atg5 and Atg7 along with the stress response protein heat shock protein 27. Specific examination of media conditioned by the Gram-positive bacterium Bifidobacterium breve (Bb-CM) showed that this microbe produces small molecules (<3 kDa) that increase expression of the autophagy proteins Atg5 and Atg7, activate autophagy, and inhibit proteasomal enzyme activity. Upregulation of autophagy by Bb-CM was mediated through MAP kinase signaling. In vitro studies using C2BBe1 cells silenced for Atg7 and in vivo studies using mice conditionally deficient in intestinal epithelial cell Atg7 showed that Bb-CM-induced cytoprotection is dependent on autophagy. Therefore, this work demonstrates that Gram-positive bacteria modify protein degradation programs within intestinal epithelial cells to promote their survival during stress. It also reveals the therapeutic potential of soluble molecules produced by these microbes for prevention and treatment of gastrointestinal disease.

PSEUDO-DIVERTICULAR FORMATION DUE TO A CYTOMEGALOVIRUS INFECTION IN THE COLORECTUM

While cytomegalovirus (CMV) infection presents as various lesions, such as patchy erythema, exudates, erosions and ulcers in the colorectum, no case has been reported where it led to a strong colonic deformity and subsequently to a diverticulum. The present report presents two cases of pseudo-diverticulum caused by a CMV infection in the colorectum. A 70-year-old man presented with severe abdominal pain. A blood examination revealed a high level of C-reactive protein (CRP; 22.08 mg/dL) but a normal number of white blood cells. A cytomegalovirus antigenemia test of his serum was negative. Abdominal computed tomography revealed a stricture and dilatation at the sigmoid colon, which seemed to be a colonic ileus. Colonoscopy showed a deep ulcer at the sigmoid colon. The pathological findings of the biopsy specimen showed inclusion bodies with a strong immunoreactivity for anti-CMV antibody. He was treated with ganciclovir for 1 month. After the anti-CMV therapy, colonoscopy detected a pseudo-diverticulum at the site corresponding to the deep ulcer (Fig. 1). A 70-year-old man was admitted to the hospital with fresh melena. An examination of his peripheral blood revealed severe anemia (hemoglobin 6.9 g/dL). He was positive for serum CMV antigenemia (10/35 000). Colonoscopy detected a deep hemorrhagic ulceration in the rectum. Emergency hemostatic treatment was carried out using a clipping procedure. The patient was treated with ganciclovir for 28 days. Colonoscopy revealed a deformity likely to be a pseudodiverticulum after the treatment at the site corresponding to the ulceration (Fig. 2). These cases are the first evidence to suggest that a deep ulceration due to CMV infection may progress to a pseudodiverticulum after the treatment of a CMV infection. Therefore, patients who present with a large intestinal diverticulum, particularly a rectal diverticulum, which rarely occurs in adulthood, may have a history of severe CMV infections with colonic ileus or hemorrhagic ulcerations.