No abstract

Background: Chronic constipation, including functional constipation and constipation-type irritable bowel syndrome, is a prevalent, multifactorial gastrointestinal disorder, and its etiology and pathophysiology remain poorly understood. Recently studies using 16S rRNA-based microbiota profiling have demonstrated dysbiosis of gut microbiota in chronic constipation. Aims: To provide an overview of recent studies for microbiota in chronic constipation and treatments for chronic constipation using probiotics, prebiotics, synbiotics, antibiotics and fecal microbiota transplantation (FMT). Methods: PubMed searches were performed up to 1 August 2018 using keywords: “IBS,” “IBS-C,” “irritable bowel syndrome,” “irritable bowel syndrome with constipation,” “functional constipation,” “chronic constipation” in combination with “gut microbiota,” “dysbiosis,” “gut microflora” for microbiota in chronic constipation, and in combination with “probiotics,” “prebiotics,” “synbiotics,” “antibiotics,” and “fecal microbiota transplantation.” Results: The findings of gut microbiota in functional constipation are inconsistent, and currently no consensus exists. Although no clear consensus exists, compared with healthy subjects, IBS-C patients have a lower level of Actinobacteria, including Bifidobacteria , in their fecal samples and a higher level of Bacteroidetes in their mucosa. In most randomized controlled and parallel-group trials, probiotics, prebiotics, synbiotics, antibiotics, and FMT therapy for chronic constipation were effective with few side effects. However, there are many studies in a small number and the types of probiotics are different, it is difficult to evaluate the effect. Conclusions: Evidence indicates that dysbiosis of gut microbiota may contribute to functional constipation and constipation-type irritable bowel syndrome. Targeting treatments for the dysbiosis of constipation by probiotics, prebiotics, synbiotics, antibiotics, and FMT may be a new option, especially for refractory constipation to conventional therapies.

Uncoupling protein 2 (UCP2) is an important regulator of intracellular reactive oxygen species (ROS) production. We determined the effects of calorie restriction (CR) on the dynamic aspects of mitochondrial ROS production, UCP2, and the nitric oxide (NO)-cGMP pathway in the cardiovascular tissues of type II diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Some rats were on restricted diets (30% reduction from free intake) from age 29 to 42 weeks. Blood glucose, hemoglobin A1c, plasma levels of free fatty acid, triacylglycerol, and plasminogen activator inhibitor-1 in OLETF rats were significantly higher than those in nondiabetic control [Long-Evans Tokushima Otsuka (LETO)] rats at 29 weeks. Mitochondrial ROS production and UCP2 expression significantly increased in the heart and aorta of OLETF rats compared with those in LETO rats. A fibrogenic growth factor, transforming growth factor (TGF)-␤1 in the coronary vessels, endothelial nitric-oxide synthase, and aortic nitrotyrosine were increased in OLETF rats at 42 weeks. In contrast, an index of the NO-cGMP pathway, phosphorylated vasodilator-stimulated phosphoprotein, and superoxide dismutase activity in the aorta were significantly diminished. The relationship between UCP2 and ROS production in the cardiovascular function of diabetic rats being fed a calorie-restricted diet is unknown. These abnormalities in OLETF rats were reversed to normal levels by CR. CR significantly improved the NO-cGMP pathway via normalizing ROS generation in OLETF rats. A decrease in UCP2 expression by CR may be a compensatory mechanism to counteract decreased intracellular oxidative stress. The data suggest that CR may prevent cardiovascular tissues from oxidative stress provoked by diabetes mellitus.Calorie restriction (CR) is shown to improve some diabetic abnormalities in this article. Cardiovascular disease is prevalent in patients with diabetes mellitus. High blood glucose levels, altered insulin signaling, reactive oxygen species (ROS), inflammation, and protein kinase C activation may lead to a decrease in nitric oxide (NO) bioavailability (Endemann and Schiffrin, 2004). It is well known that diabetes mellitus provokes an increase in oxidative stress in vascular cells and cardiomyocytes. High glucose concentrations, which contribute to the pathogenesis of atherosclerosis in patients with diabetes, lead to intracellular oxidative stress (Baynes, 1991;Baynes and Thorpe, 1999).The Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of spontaneous type II diabetes, develops hyperglycemic obesity with hyperinsulinemia and insulin resistance after the age of 25 weeks, similar to patients with noninsulindependent diabetes mellitus. In the aorta from OLETF rats,

It has been proposed in human colorectal cancers (CRC), a minority subset of cancer cells within tumors able to initiate tumor growth, defined as cancer stem cells (CSC). Solid human primary colonic and its ovarian metastatic cancer tissues were collected from fresh surgical samples and subsequent xenografts were established in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. The resulting tumors were disaggregated into single-cell suspensions and a CD133 negative cell line (NANK) was newly established and analyzed by flow cytometry. Surface markers of progenitor cells were immunophenotypically analyzed, and expression of stem cell and cancer-related genes were characterized. Secreted angiogenesis-associated molecules were investigated by proteomic array technology. Finally, different number of NANK was implanted and their tumor-initiating properties were investigated in NOD/SCID mice. Intraperitoneal injection of NANK in NOD/SCID mice induced tumors with developing progressive peritoneal dissemination and ascites. NANK cells maintained a differentiated phenotype and reproduced the full morphologic and phenotypic heterogeneity of their parental lesions. Noticeably, NANK lacked the expression of conventional CSC markers CD133 and CD44, self-renewal genes Oct-4 and Nanog, but showed the expression of an important gastrointestinal development marker CDX-2 and BMI-1 that is essential in regulating the proliferative activity of normal and leukemic stem cells. In addition, NANK secreted high amounts of important angiogeneic cytokines. These results provide a novel and extensive model in human CSC for studying the generation and maintenance of phenotypic heterogeneity in CRC.

Induced pluripotent stem (iPS) cells are pluripotent and are able to unlimitedly proliferate in vitro. This technical breakthrough in creating iPS cells from somatic cells has noteworthy implications for overcoming the immunological rejection and the ethical issues associated with the derivation of embryonic stem cells from embryos. In the current work, we present an efficient hepatic differentiation of mouse iPS cells in vitro. iPS cells were cultured free floating to induce the formation of embryoid bodies (EB) for 5 days. EB were transferred to a gelatin-coated plate and treated with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF) for 3 days to induce definitive endoderm. Cells were further cultured for 8 days with 100 ng/ml hepatocyte growth factor (HGF) to generate hepatocytes. Characterization was performed by RT-PCR assay. Functional analysis for albumin secretion and ammonia removal was also carried out. iPS cellderived hepatocyte-like cells (iPS-Heps) were obtained at the end of the differentiation program. Expression levels of a gestational hepatocyte gene and lineage-specific hepatic genes intensified in iPS-Heps. The production of albumin increased in a time-dependent manner. iPS-Heps were capable of metabolizing ammonia. We present here instant hepatic differentiation of mouse iPS cells using combined 3-day treatments of activin A and bFGF with subsequent 8-day HGF. Our study will be an important step to generate hepatocytes from human iPS cells as a new source for liver-targeted cell therapies.