A water channel closely related to rat brain aquaporin 4 is expressed in acid- and pepsinogen-secretory cells of human stomach

AbstractWe isolated a cDNA clone encoding a water channel protein, aquaporin (AQP), from human stomach. The encoded protein consisted of 323 amino acid residues, containing six putative transmembrane domains. The protein was designated human aquaporin 4 (hAQP4) because of its 94% sequence similarity to rat brain AQP4. Expression of hAQP4 cRNA in Xenopus oocytes resulted in a significant increase in osmotic water permeability, indicating that this protein functions as a water channel. Northern blot analysis demonstrated a strong signal of hAQP4 mRNA in brain, lung, and skeletal muscle as well as in stomach. Immunohistochemical experiments with human stomach tissues showed that hAQP4 as a protein is expressed mainly in cells located in the glandular portion of the fundic mucosa. These include chief cells which secrete pepsinogen and parietal cells which secrete hydrochloric acid. These results strongly indicate that hAQP4 is a principal factor involved in the osmotic regulation of pepsinogen and acid secretion in the stomach

Transcriptional repression and DNA hypermethylation of a small set of ES cell marker genes in male germline stem cells

BACKGROUND: We previously identified a set of genes called ECATs (ES cell-associated transcripts) that are expressed at high levels in mouse ES cells. Here, we examine the expression and DNA methylation of ECATs in somatic cells and germ cells. RESULTS: In all ECATs examined, the promoter region had low methylation levels in ES cells, but higher levels in somatic cells. In contrast, in spite of their lack of pluripotency, male germline stem (GS) cells expressed most ECATs and exhibited hypomethylation of ECAT promoter regions. We observed a similar hypomethylation of ECAT loci in adult testis and isolated sperm. Some ECATs were even less methylated in male germ cells than in ES cells. However, a few ECATs were not expressed in GS cells, and most of them targets of Oct3/4 and Sox2. The Octamer/Sox regulatory elements were hypermethylated in these genes. In addition, we found that GS cells express little Sox2 protein and low Oct3/4 protein despite abundant expression of their transcripts. CONCLUSION: Our results suggest that DNA hypermethylation and transcriptional repression of a small set of ECATs, together with post-transcriptional repression of Oct3/4 and Sox2, contribute to the loss of pluripotency in male germ cells

Toll-like receptor-2-activating bifidobacteria strains differentially regulate inflammatory cytokines in the porcine intestinal epithelial cell culture system: Finding new anti-inflammatory immunobiotics

A total of 23 strains of bifidobacteria taxonomically belonging to five species were tested for their potent immunomodulatory effect using a combination of two methods: the NF-κB-reporter assay using a toll-like receptor 2-expressing transfectant (HEK pTLR2 system) and the mitogenic assay using porcine Peyer's patches immunocompetent cells. Among the four preselected strains from different immunomodulatory groups, Bifidobacterium breve MCC-117 was able to efficiently modulate the inflammatory response triggered by enterotoxigenic Escherichia coli (ETEC) in a porcine intestinal epithelial (PIE) cell line. Moreover, using PIE cells and swine Peyer's patches immunocompetent cell co-culture system, we demonstrated that the immunoregulatory effect of B. breve MCC-117 was related to the capacity of the strain to influence PIE and immune cell interactions, leading to the stimulation of regulatory T cells. The results suggested that bifidobacteria that express high activity in both the HEK pTLR2 and the mitogenic assays may behave like potential anti-inflammatory strains. The combination of the HEK pTLR2 system, the evaluation of mitogenic activity and PIE cells will be of value for the development of new immunologically functional foods and feeds that could prevent inflammatory intestinal disorders. Although our findings should be proven in appropriate experiments in vivo, the results of the present work provide a scientific rationale for the use of B. breve MCC-117 to prevent ETEC-induced intestinal inflammation.Fil: Fujie, Hitomi. Tohoku University; JapónFil: Villena, Julio Cesar. Tohoku University; Japón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Tohno, Masanori. National Agricultural Research Organization. National Institute of Livestock and Grassland Science. Functional Feed Research Team; JapónFil: Morie, Kyoko. Tohoku University; JapónFil: Shimazu, Tomoyuki. Tohoku University; JapónFil: Aso, Hisashi. Tohoku University; JapónFil: Suda, Yoshihito. Miyagi University; JapónFil: Shimosato, Takeshi. Shinshu University; JapónFil: Iwabuchi, Noriyuki. Morinaga Milk Industry Co. Ltd. Food Science and Technology Institute; JapónFil: Xiao, Jin-Zhong. Morinaga Milk Industry Co. Ltd. Food Science and Technology Institute; JapónFil: Yaeshima, Tomoko. Morinaga Milk Industry Co. Ltd. Food Science and Technology Institute; JapónFil: Iwatsuki, Keiji. Morinaga Milk Industry Co. Ltd. Food Science and Technology Institute; JapónFil: Saito, Tadao. Tohoku University; JapónFil: Numasaki, Muneo. Josai University; JapónFil: Kitazawa, Haruki. Tohoku University; Japó

Molecular insights of a CBP/β-catenin-signaling inhibitor on nonalcoholic steatohepatitis-induced liver fibrosis and disorder

Nonalcoholic steatohepatitis (NASH) is a progressive fibrotic disease associated with an increased risk of developing hepatocellular carcinoma; at present, no efficient therapeutic strategy has been established. Herein, we examined the efficacy of PRI-724, a potent inhibitor of CBP/β-catenin signaling, for treating NASH-related liver fibrosis and disorder and characterized its mechanism.Choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD)-fed mice exhibited NASH-induced liver fibrosis that is characterized by steatosis, lobular inflammation, hepatocellular injury and collagen fibrils. To examine the therapeutic effect, CDAHFD-fed mice were administered PRI-724.Serum levels of ALT and pro-fibrotic molecule, i.e. Mac-2 bp, alpha smooth muscle actin, type I and type III collagens, decreased significantly. mRNA levels of the matrix metalloproteinases Mmp8 and Mmp9 in the liver were significantly increased, and increases in the abundance of MMP9-producing neutrophils and macrophages were observed. Marco+Mmp9+Cd68+ Kupffer cells were only observed in the livers of mice treated with PRI-724, and Mmp9 expression in Marco+Cd68+ Kupffer cells increased 4.3-fold. Moreover, hepatic expression of the lipid metabolism regulator, pyruvate dehydrogenase kinase 4 and liver lipid droplets also decreased significantly.PRI-724-treated NASH mice not only recovered from NASH-related liver fibrosis through the effect of PRI-724 down-regulating the expression of pro-fibrotic genes and up-regulating the expression of anti-fibrotic genes, but they also recovered from NASH-induced liver disorder. PRI-724, a selective CBP/β-catenin inhibitor, thus shows a potent therapeutic effect for NASH-related liver fibrosis and for decreasing adipose tissue in the liver