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Objective: Chronic intestinal inflammation is a risk factor for colorectal cancer (CRC) initiation and development. Diets that are rich in Western style fats have been shown to promote CRC. This study was conducted to investigate the role of intestinal microbiome in American ginseng-mediated CRC chemoprevention in a mouse model. The population and diversity of enteric microbiome were evaluated after the ginseng treatment.Methods: Using an azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced gut inflammation and tumorigenesis mouse model, the effects of oral American ginseng on high fat diet-associated enteric pathology were determined. After establishment of a 16S rRNA illumina library from fecal samples, MiSeq sequencing was carried out to reveal the microbial population. The alpha and beta diversities of microbiome were analyzed.Results: American ginseng significantly attenuated AOM/DSS-induced colon inflammation and tumorigenesis by reducing the colitis score and colon tumor multiplicity. The MiSeq results showed that the majority of sequences fell into three phyla: Firmicutes, Bacteroidetes and Verrucomicrobia. Further, two significant abundance shifts at the family level, Bacteroidaceae and Porphyromonadaceae, were identified to support ginseng’s anti-colitis and anti-tumor effects. In addition, alpha and beta diversity data demonstrated that ginseng led to a profound recovery from the AOM/DSS-induced dysbiosis in the microbial community.Conclusion: Our results suggest that the CRC chemopreventive effects of American ginseng are mediated through enteric microbiome population-shift recovery and dysbiosis restoration. Ginseng’s regulation of the microbiome balance contributes to the maintenance of enteric homeostasis. [ABSTRACT FROM AUTHOR]

The aim of this study was to express the cloned skate anion exchanger 1 (skAE1) in Xenopus oocytes and determine whether the differences in monovalent cation permeabilities in hypotonically stimulated skate and trout erythrocytes could be due to differences in the presence or absence of intracellular channel regulators between the two species or in the intrinsic permeability properties of the channels themselves. The expressed protein (skAE1) was inserted into the oocyte cell membrane and facilitated both Cl- exchange and taurine transport. Expression of skAE1 in oocytes showed similar monovalent cation permeabilities as previously reported for skate erythrocytes and different from both trout erythrocytes and trAE1 expressed in Xenopus oocytes. These results show that the skAE1 expressed in oocytes functions in a manner similar to that of the osmolyte channel in hypotonically activated skate erythrocytes and supports the hypothesis that differences in the monovalent cation permeabilities of the osmolyte channels in skate and trout RBCs resides in the differences in permeability properties of the channels between the two species. [ABSTRACT FROM AUTHOR]

During cell swelling, cells release organic osmolytes via a volume-activated channel as part of the regulatory volume decrease. The erythrocyte membrane protein AE1 (band 3), has been shown to be involved in regulatory volume responses of fish erythrocytes. Previous studies showed that the expression of trout AE1 in Xenopus laevis oocytes induces band 3 anion exchange activity and organic osmolyte channel activity. However, an endogenous swelling-activated anion channel, IClswell, is present in Xenopus oocyte membranes. Therefore, it is not yet known whether a new organic osmolyte channel is formed or whether the endogenous channel, IClswell, is activated when trout AE1 is expressed in the oocytes. The purpose of this study was to determine whether the expression of trout AE1 in Xenopus oocytes leads to the formation and membrane insertion of a new organic osmolyte channel or activates IClswell. To differentiate between the two possibilities, we compared the time courses, pH profiles and inhibitor sensitivities of both trout AE1 and IClswell. The results of taurine-uptake experiments show that the time courses and pH levels for optimum expression of trout AE1 and IClswell differ significantly. The inhibitor sensitivities of the organic osmolyte channel mediated by trout AE1 and IClswell are also significantly different, strongly suggesting that the expression of trout AE1 in Xenopus oocytes does not activate IClswell, but rather forms a new organic osmolyte channel. [ABSTRACT FROM AUTHOR]

Na-K-Cl cotransport stoichiometry and affinities for Na, K and Cl were determined in flounder intestine. Measurement of simultaneous NaCl and RbCl influxes resulted in ratios of 2.2 for Cl/Na and 1.8 for Cl/Rb. The effect of Na and Rb on Rb influx showed first order kinetics with K1/2 values of 5 and 4.5 mM and Hill coefficients of 0.9 and 1.2, respectively. The effect of Cl on rubidium influx showed a sigmoidal relationship with K1/2 of 20 mM and a Hill coefficient of 2.0. The effects of variations in Na and Cl concentration on short-circuit current (Isc) were also determined. The K1/2 for Na was 7 mM with a Hill coefficient of 0.9 and the K1/2 for Cl was 46 mM with a Hill coefficient of 1.9. Based on the simultaneous influx measurements, a cotransport stoichiometry of 1Na:1K:2Cl is concluded. The Hill coefficients for Cl suggest a high degree of cooperativity between Cl binding sites. Measurements of the ratio of net Na and Cl transepithelial fluxes under short-circuit conditions (using a low Na Ringer solution to minimize the passive Na flux) indicate that the Cl/Na flux ratio is approximately 2:1. Therefore, Na recycling from serosa to mucosa does not significantly contribute to the Isc. Addition of serosal ouabain (100 microM) inhibited Rb influx, indicating that Na-K-Cl cotransport is inhibited by ouabain. This finding suggests that a feedback mechanism exists between the Na-K-ATPase on the basolateral membrane and the apical Na-K-2Cl cotransporter. [ABSTRACT FROM AUTHOR]

This article was originally published with the wrong title. [ABSTRACT FROM AUTHOR]