A ketogenic diet improves the prognosis in a mouse model of peritoneal dissemination without tumor regression.

Peritoneal dissemination describes a state where tumor cells spread to the surface of the peritoneum and become engrafted. Peritoneal dissemination reduces the quality of life and prognosis of cancer patients. Currently, there are few effective therapies or preventative treatments for peritoneal dissemination. The aim of this study was to evaluate a ketogenic diet, characterized by high fat, moderate protein and low carbohydrate content, as a novel therapy in a mouse model of peritoneal dissemination. BALB/c mice were intraperitoneally inoculated with colon 26, a murine colon adenocarcinoma cell line, to induce experimental peritoneal dissemination. After tumor inoculation, mice were fed a regular or ketogenic diet. A longer survival time and better health status score, related to improved behavior, was observed in the ketogenic diet group compared with the regular diet group. In addition, the weight of ascites was significantly smaller and the anemia symptoms, number of red blood cell, hemoglobin and hematocrit, were improved in the ketogenic diet group compared with the regular diet group. However, the tumor weight was not significantly smaller in the ketogenic diet group compared with the regular diet group. These data suggest that a ketogenic diet might be a potential preventive therapy for peritoneal dissemination.

Decreased abundance of Faecalibacterium prausnitzii in the gut microbiota of Crohn's disease.

BACKGROUND AND AIMS: Dysbiosis is thought to be relevant to the etiology and pathogenesis of Crohn's disease (CD). In this study, we investigated the abundance of Faecalibacterium prausnitzii, as well as Bilophila wadsworthia, in the gut microbiota of Japanese CD patients. METHODS: Forty-seven CD patients and 20 healthy controls were enrolled. Abundance of F. prausnitzii in fecal samples was quantified by real-time polymerase chain reaction. The gut microbiota profile was evaluated by terminal restriction fragment length polymorphisms. RESULTS: The abundance of F. prausnitzii significantly decreased in CD patients compared with healthy subjects. B. wadsworthia was scarcely detected in the same samples. Among CD patients, the Crohn's Disease Activity Index, C-reactive protein levels, and erythrocyte sedimentation rate were significantly lower, and serum albumin levels were significantly higher in the high F. prausnitzii group compared with the low group. Terminal restriction fragment length polymorphisms analysis showed that fecal bacterial communities of CD patients differed from those of healthy individuals. The changes in simulated bacterial composition indicated that class Clostridia, including genus Faecalibacterium, was significantly less abundant in CD patients as compared with healthy individuals. The bacterial diversity measured by the Shannon Diversity Index was significantly reduced in CD patients compared with healthy individuals. CONCLUSION: The decreased abundance of class Clostridia, including F. prausnitzii, may translate into a reduction of commensal bacteria-mediated, anti-inflammatory activities in the mucosa, which are relevant to the pathophysiology of CD. In contrast, the role of B. wadsworthia was suspected to be minimal.

Neutralization of complement component C5 ameliorates the development of dextran sulfate sodium (DSS)-colitis in mice.

The complement system is a potent effector of innate immunity. To elucidate the pathophysiological role of the complement system in inflammatory bowel disease, we evaluated the effects of anti-C5 antibodies on the development of dextran sulfate sodium-induced colitis in mice. Dextran sulfate sodium-colitis was induced in BALB/c mice with intraperitoneal administrations of anti-C5 antibodies (1 mg/body [DOSAGE ERROR CORRECTED]) every 48 h. Tissue samples were evaluated by standard histological procedures. The mucosal mRNA expression of the inflammatory cytokines was analyzed by real-time PCR. Body weight loss in the mice was completely blocked by the administration of anti-C5 antibody. The disease activity index was significantly lower in the anti-C5 antibody-treated mice than the dextran sulfate sodium mice. The colonic weight/length ratio, histological colitis score and mucosal myeloperoxidase activity were significantly lower in the anti-C5 antibody-treated mice than the dextran sodium sulfate mice. The administration of the anti-C5 antibody significantly reduced the mucosal expression of mRNAs for tumor necrosis factor-α, interleukin-1ß and interleukin-6. In conclusion, the complement system plays a role in the development of dextran sodium sulfate-induced experimental colitis.

Development and Characterization of a Cancer Cachexia Rat Model Transplanted with Cells of the Rat Lung Adenocarcinoma Cell Line Sato Lung Cancer (SLC).

Cancer cachexia is a complex malnutrition syndrome that causes progressive dysfunction. This syndrome is accompanied by protein and energy losses caused by reduced nutrient intake and the development of metabolic disorders. As many as 80% of patients with advanced cancer develop cancer cachexia; however, an effective targeted treatment remains to be developed. In this study, we developed a novel rat model that mimics the human pathology during cancer cachexia to elucidate the mechanism underlying the onset and progression of this syndrome. We subcutaneously transplanted rats with SLC cells, a rat lung adenocarcinoma cell line, and evaluated the rats' pathophysiological characteristics. To ensure that our observations were not attributable to simple starvation, we evaluated the characteristics under tube feeding. We observed that SLC-transplanted rats exhibited severe anorexia, weight loss, muscle atrophy, and weakness. Furthermore, they showed obvious signs of cachexia, such as anemia, inflammation, and low serum albumin. The rats also exhibited weight and muscle losses despite sufficient nutrition delivered by tube feeding. Our novel cancer cachexia rat model is a promising tool to elucidate the pathogenesis of cancer cachexia and to conduct further research on the development of treatments and supportive care for patients with this disease.

The solute carrier family 15A4 regulates TLR9 and NOD1 functions in the innate immune system and promotes colitis in mice.

BACKGROUND & AIMS: Solute carrier family 15 (SLC15) A4 is a proton-coupled histidine and oligopeptide cotransporter expressed by the immune and nervous systems and associated with disorders such as inflammatory bowel diseases and systemic lupus erythematosus. High levels of SLC15A4 transcripts were observed in human antigen-presenting cells, including dendritic cells, activated macrophages, and B cells. However, the roles of SLC15A4 in the immune regulation are not known. We investigated the function of SLC15A4 in the innate immune system. METHODS: We created SLC15A4-deficient (SLC15A4(-/-)) mice and compared Toll-like receptor 9 and NOD1-dependent innate immune responses between SLC15A4(-/-) and control (SLC15A4(+/+)) mice. RESULTS: SLC15A4 deficiency impaired CpG-induced production of interleukin-12, interleukin-15, and interleukin-18 by dendritic cells. Correspondingly, SLC15A4(-/-) mice developed a less severe form of Th1-dependent colitis than SLC15A4(+/+) mice. Increased lysosomal histidine, in the absence of SLC15A4, appears to negatively regulate Toll-like receptor 9 function by inhibiting the proteolytic activities of cathepsins B and L. SLC15A4(-/-) mice also had a severe defect in NOD1-dependent cytokine production, indicating that SLC15A4 functions as a transporter of the NOD1 ligand. CONCLUSIONS: SLC15A4 promotes colitis through Toll-like receptor 9 and NOD1-dependent innate immune responses. Histidine homeostasis within intracellular compartments is important for eliciting effective innate immune responses.

Terminal-restriction fragment length polymorphism (T-RFLP) analysis for changes in the gut microbiota profiles of indomethacin- and rebamipide-treated mice.

BACKGROUND/AIMS: We investigated the effects of indomethacin and rebamipide on the gut microbiota profiles using terminal restriction fragment polymorphism (T-RFLP) analysis. MATERIALS AND METHODS: Female C57BL/6J mice were given indomethacin (10 mg/kg, s.c.) once a day and 2.5 mg rebamipide orally 3 times a day. After 7 days, they were sacrificed, and luminal contents were obtained from the ileum and cecum. The gut microbiota communities were analyzed by T-RFLP analysis with BslI digestion. RESULTS: T-RFLP analyses showed that rebamipide and indomethacin had no significant effects on the gut microbiota profiles in the ileum and cecum. In contrast, the combination of rebamipide + indomethacin induced a significant change in the gut microbiota. The changes in the microbiota composition induced by the combination of rebamipide + indomethacin were characterized by the increase in the orders Bifidobacteriales and Lactobacillales, the genera Bacteroides and Prevotella and the family Clostridiaceae. The diversity of the gut microbiota community generated by the combination of rebamipide + indomethacin was significantly higher than those induced by either rebamipide or indomethacin alone. CONCLUSION: The combination of rebamipide + indomethacin induces remarkable changes in the gut microbiota composition and diversity. The clinical activity of rebamipide on nonsteroidal anti-inflammatory drug-induced intestinal injury may be exerted through a modulation of the gut microbiota.

Spatiotemporal regulation of intracellular trafficking of Toll-like receptor 9 by an inhibitory receptor, Ly49Q.

Toll-like receptor (TLR) 9 recognizes unmethylated microorganismal cytosine guanine dinucleotide (CpG) DNA and elicits innate immune responses. However, the regulatory mechanisms of the TLR signaling remain elusive. We recently reported that Ly49Q, an immunoreceptor tyrosine-based inhibitory motif-bearing inhibitory receptor belonging to the natural killer receptor family, is crucial for TLR9-mediated type I interferon production by plasmacytoid dendritic cells. Ly49Q is expressed in plasmacytoid dendritic cells, macrophages, and neutrophils, but not natural killer cells. In this study, we showed that Ly49Q regulates TLR9 signaling by affecting endosome/lysosome behavior. Ly49Q colocalized with CpG in endosome/lysosome compartments. Cells lacking Ly49Q showed a disturbed redistribution of TLR9 and CpG. In particular, CpG-induced tubular endolysosomal extension was impaired in the absence of Ly49Q. Consistent with these findings, cells lacking Ly49Q showed impaired cytokine production in response to CpG-oligodeoxynucleotide. Our data highlight a novel mechanism by which TLR9 signaling is controlled through the spatiotemporal regulation of membrane trafficking by the immunoreceptor tyrosine-based inhibitory motif-bearing receptor Ly49Q.

A novel highly concentrated enteral nutrition formula, EN-P05, shows nutritional effectiveness comparable to the approved OSN-001 in gastrostomized rats.

Enteral nutrition is beneficial support administered as oral supplements or via tube feeding for patients with long-term inability to meet nutritional requirements orally. However, because of the high volumes administered, vomiting and gastroesophageal reflux are often encountered in patients receiving enteral nutrition. EN-P05 is a novel, highly concentrated enteral nutrition formula that was developed to reduce dosing volume and that satisfies the Japanese recommended daily allowance for most vitamins and trace elements, even in patients who require low-calorie control, such as home-care patients. However, whether EN-P05 can provide nutritional management equivalent to that provided by approved formulas has remained unknown. To investigate the nutritional effectiveness of EN-P05, we evaluated body weight gain, serum chemistry parameters, nitrogen balance, and fat absorption in 7-week-old gastrostomized rats that received either EN-P05 or OSN-001 for 2 weeks. No difference in organ or carcass weight was found between the groups. No significant between-group differences were observed in serum albumin, total protein, triglycerides, or total cholesterol, nor in nitrogen retention or fat absorption rate. No adverse effects associated with administration of EN-P05 were found. These results suggest that EN-P05 can provide the same nutritional management as approved formulas, even when administered in smaller volume.

Tacrolimus (FK506) suppresses TNF-α-induced CCL2 (MCP-1) and CXCL10 (IP-10) expression via the inhibition of p38 MAP kinase activation in human colonic myofibroblasts.

In order to investigate the molecular mechanisms underlying the immunosuppressive effects of tacrolimus (FK506) on intestinal inflammation, we examined whether FK506 effects cytokine/chemokine secretion in human colonic myofibroblasts. Human colonic myofibroblasts were isolated from normal human colonic tissue. The mRNA and protein expression for human CCL2 and CXCL10 were analyzed by real-time PCR and ELISA, respectively. p38 MAP kinase activation was evaluated by western blotting. Tacrolimus (1 µM) suppressed tumor necrosis factor (TNF)-α-induced CCL2 and CXCL10 mRNA expression, but did not modulate TNF-α-induced interleukin (IL)-6 or CXCL8 mRNA expression. Dose-dependent, inhibitory effects of tacrolimus on CCL2 and CXCL10 expression were observed at the mRNA and protein levels. Significant inhibitory effects of tacrolimus were observed at concentrations as low as 0.5 µM for CCL2 and 0.1 µM for CXCL10, respectively. TNF-α-induced CCL2 and CXCL10 expression depended on p38 MAP kinase activation, and tacrolimus strongly inhibited the TNF-α-induced phosphorylation of p38 MAP kinase. Tacrolimus did not affect interferon (IFN)-γ-induced signaling transducer and activator of transcription (STAT)-1 phosphorylation, nor did it modulate CXCL10 mRNA and protein expression. In conclusion, tacrolimus suppressed CCL2 and CXCL10 expression in human colonic myofibroblasts. These inhibitory effects of tacrolimus may play key roles in the therapeutic effects of colonic inflammation in inflammatory bowel disease (IBD) patients.