Masashi Ohno

Analysis of endoscopic brush samples identified mucosa-associated dysbiosis in inflammatory bowel disease

BackgroundThe mucosa-associated gut microbiota directly modulates epithelial and mucosal function. In this study, we investigated the mucosa-associated microbial community in patients with inflammatory bowel disease (IBD), using endoscopic brush samples.MethodsA total of 174 mucus samples from 43 patients with ulcerative colitis (UC), 26 with Crohn’s disease (CD) and 14 non-IBD controls were obtained by gentle brushing of mucosal surfaces using endoscopic cytology brushes. The gut microbiome was analyzed using 16S rRNA gene sequencing.ResultsThere were no significant differences in microbial structure among different anatomical sites (the ileum, cecum and sigmoid colon) within individuals. There was, however, a significant difference in microbial structure between CD, UC and non-IBD controls. The difference between CD and non-IBD controls was more marked than that between UC patients and non-IBD controls. α-Diversity was significantly lower in UC and CD patients than non-IBD controls. When comparing CD patients with non-IBD controls, the phylum Proteobacteria was significantly increased and the phyla Firmicutes and Bacteroidetes were significantly reduced. These included a significant increase in the genera Escherichia, Ruminococcus (R. gnavus), Cetobacterium, Actinobacillus and Enterococcus, and a significant decrease in the genera Faecalibacterium, Coprococcus, Prevotella and Roseburia. Comparisons between CD and UC patients revealed a greater abundance of the genera Escherichia, Ruminococcus (R. gnavus), Clostridium, Cetobacterium, Peptostreptococcus in CD patients, and the genera Faecalibacterium, Blautia, Bifidobacterium, Roseburia and Citrobacter in UC patients.ConclusionsMucosa-associated dysbiosis was identified in IBD patients. CD and UC may be distinguishable from the mucosa-associated microbial community structure.

Influence of potassium-competitive acid blocker on the gut microbiome of Helicobacter pylori-negative healthy individuals

We read with great interest two recent reports by Imhann et al 1 and Jackson et al .2 Through large population-cohort study, each group revealed that gastric acid inhibition by long-term use of proton pump inhibitors (PPIs) changes the gut microbiome to predispose to enteric infection including Clostridium difficile (CD) . Potassium-competitive acid blockers (P-CABs) have been reported to exert more potent gastric acid suppression than PPIs.3 ,4 The inhibitory effect of vonoprazan (TAK-438), a new P-CAB, on H+, K+-ATPase in vitro is approximately 400 times more potent than that of PPI (lansoprazole) (inhibitory concentration (IC)50 of vonoprazan 0.019 μM and lansoprazole 7.6 μM).5 We describe below that vonoprazan induces more complex alteration of the gut microbiome as compared with lansoprazole. We enrolled serum Helicobacter pylori IgG-negative healthy individuals to eliminate the influence of H. pylori infection on gastric acid secretion (see online supplementary table S1). The PPI group (n=11) took 30 mg of lansoprazole daily for 4 weeks, and the P-CAB group …

Nanoparticle curcumin ameliorates experimental colitis via modulation of gut microbiota and induction of regulatory T cells

Background and Aims Curcumin is a hydrophobic polyphenol derived from turmeric, a traditional Indian spice. Curcumin exhibits various biological functions, but its clinical application is limited due to its poor absorbability after oral administration. A newly developed nanoparticle curcumin shows improved absorbability in vivo. In this study, we examined the effects of nanoparticle curcumin (named Theracurmin) on experimental colitis in mice. Methods BALB/c mice were fed with 3% dextran sulfate sodium (DSS) in water. Mucosal cytokine expression and lymphocyte subpopulation were analyzed by real-time PCR and flow cytometry, respectively. The profile of the gut microbiota was analyzed by real-time PCR. Results Treatment with nanoparticle curcumin significantly attenuated body weight loss, disease activity index, histological colitis score and significantly improved mucosal permeability. Immunoblot analysis showed that NF-κB activation in colonic epithelial cells was significantly suppressed by treatment with nanoparticle curcumin. Mucosal mRNA expression of inflammatory mediators was significantly suppressed by treatment with nanoparticle curcumin. Treatment with nanoparticle curcumin increased the abundance of butyrate-producing bacteria and fecal butyrate level. This was accompanied by increased expansion of CD4+ Foxp3+ regulatory T cells and CD103+ CD8α− regulatory dendritic cells in the colonic mucosa. Conclusions Treatment with nanoparticle curcumin suppressed the development of DSS-induced colitis potentially via modulation of gut microbial structure. These responses were associated with induction of mucosal immune cells with regulatory properties. Nanoparticle curcumin is one of the promising candidates as a therapeutic option for the treatment of IBD.

Pyoderma Gangrenosum with Ulcerative Colitis Successfully Treated by the Combination of Granulocyte and Monocyte Adsorption Apheresis and Corticosteroids

A 36-year-old woman was admitted to our hospital due to swelling and redness of the left lateral malleolus and dorsum of the left foot with severe pain, with a flare-up of ulcerative colitis (UC). A pathologic examination by skin biopsy led to a diagnosis of pyoderma gangrenosum (PG). She was treated with the intravenous administration of prednisolone (60 mg/day), and granulocyte and monocyte adsorption apheresis (GMA) was performed twice-a-week for 5 weeks. This treatment dramatically improved both the skin and colonic mucosal lesions. These results suggest that a combination of GMA and corticosteroids might be recommendable to induce the remission of serious PG complicated with UC.

Expression of Interleukin-26 is upregulated in inflammatory bowel disease

AIM To investigate interleukin (IL)-26 expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD) and the function of IL-26. METHODS Human colonic subepithelial myofibroblasts (SEMFs) were isolated from colon tissue surgically resected. The expression of IL-26 protein and its receptor complex was analyzed by immunohistochemistry. The gene expression induced by IL-26 was evaluated by real-time polymerase chain reaction. Intracellular signaling pathways were evaluated by immunoblotting and specific small interfering (si) RNA transfection. RESULTS The mRNA and protein expression of IL-26 were significantly enhanced in the inflamed mucosa of patients with IBD. IL-26 receptor complex was expressed in colonic SEMFs in vivo and in vitro. IL-26 stimulated the mRNA expression of IL-6 and IL-8 in colonic SEMFs. The inhibitors of mitogen-activated protein kinases and phosphoinositide 3-kinase, and siRNAs for signal transducers and activator of transcription 1/3, nuclear factor-kappa B and activator protein-1 significantly reduced the mRNA expression of IL-6 and IL-8 induced by IL-26. CONCLUSION These results suggest that IL-26 plays a role in the pathophysiology of IBD through induction of inflammatory mediators.

Ameliorating effects of bortezomib, a proteasome inhibitor, on development of dextran sulfate sodium-induced murine colitis

We examined the effect of bortezomib, a proteasome inhibitor, on the development of dextran sulfate sodium (DSS)-induced colitis in mice. DSS-colitis was induced by the administration of 3% DSS in water in C57BL/6J mice. Bortezomib was intraperitoneally administered daily for 9 days from the start of DSS. Ubiquitination of IκBα was evaluated by immunoblot. Bortezomib significantly ameliorated DSS-induced body weight loss and reduced the disease activity. The translocation of NF-κBp65 into the nucleus was markedly suppressed in the DSS + bortezomib group compared to the DSS group, but this difference was not detected in submucosal tissue. Ubiquitinated IκBα in the cytoplasm of colon epithelial cells was increased in the DSS + bortezomib group compared to the DSS group. In HT-29 cells, bortezomib blocked tumor necrosis factor-α (TNF-α)-induced nuclear translocation of NF-κB and this was accompanied by an increase in ubiquitinated IκBα in the cytoplasm. The mRNA expression of inflammatory mediators in colonic epithelial cells was significantly reduced by the treatment of bortezomib. Bortezomib inhibited the nuclear translocation of NF-κB in colonic epithelial cells by suppressing the degradation of IκBα and contributed to an improvement in DSS colitis. Our study suggests that bortezomib may be a new treatment option for IBD.

Astaxanthin, a xanthophyll carotenoid, prevents development of dextran sulphate sodium-induced murine colitis

Astaxanthin is a xanthophyll carotenoid, which possesses strong scavenging effect on reactive oxygen species. In this study, we examined the effect of astaxanthin on dextran sulfate sodium (DSS)-induced colitis in mice. Experimental colitis was induced by the oral administration of 4% w/v DSS in tap water in C57BL/6J mice. Astaxanthin was mixed with a normal rodent diet (0.02 or 0.04%). Astaxanthin significantly ameliorated DSS-induced body weight loss and reduced the disease activity index. The ameliorating effects was observed in a dose-dependent manner. Immunochemical analyses showed that astaxanthin markedly suppressed DSS-induced histological inflammatory changes (inflammatory cell infiltration, edematous changes and goblet cell depletion). Plasma levels of malondialdehyde and 8-hydroxy-2-deoxyguanosine were significantly reduced by the administration of 0.04% astaxanthin. Astaxanthin significantly suppressed the mucosal mRNA expression of IL-1β, IL-6, TNF-α, IL-36α and IL-36γ. Astaxanthin blocked the DSS-induced translocation of NF-κB p65 and AP-1 (c-Jun) into the nucleus of mucosal epithelial cells, and also suppressed DSS-induced mucosal activation of MAPKs (ERK1/2, p38 and JNK). In conclusion, astaxanthin prevented the development of DSS-induced colitis via the direct suppression of NF-κB, AP-1 and MAPK activation. These findings suggest that astaxanthin is a novel candidate as a therapeutic option for the treatment of inflammatory bowel disease.