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Project description:Longitudinal zonation of epithelial cells across the mammalian small intestine defines five domains of nutrient absorption. We then performed gene expression profiling analysis using data obtained from RNA-seq of 4 different cells at two time points.
2023-11-28 | GSE201858 | GEO
Project description:Longitudinal zonation of epithelial cells across the mammalian small intestine defines five domains of nutrient absorption.
2023-11-28 | GSE201857 | GEO
Project description:Longitudinal zonation of epithelial cells across the mammalian small intestine defines five domains of nutrient absorption.
2023-11-28 | GSE201855 | GEO
Project description:Longitudinal zonation of epithelial cells across the mammalian small intestine defines five domains of nutrient absorption.
2023-12-21 | GSE251695 | GEO
Project description:Longitudinal zonation of epithelial cells across the mammalian small intestine defines five domains of nutrient absorption.
2023-12-21 | GSE251694 | GEO
Project description:Acetylcholine (ACh) is critical in controlling epithelial ion transport and hence water movements for gut hydration. Here we review the mechanism of cholinergic control of epithelial ion transport across the mammalian intestine. The cholinergic nervous system affects basal ion flux and can evoke increased active ion transport events. Most studies rely on measuring increases in short-circuit current (ISC = active ion transport) evoked by adding ACh or cholinomimetics to intestinal tissue mounted in Ussing chambers. Despite subtle species and gut regional differences, most data indicate that, under normal circumstances, the effect of ACh on intestinal ion transport is mainly an increase in Cl- secretion due to interaction with epithelial M3 muscarinic ACh receptors (mAChRs) and, to a lesser extent, neuronal M1 mAChRs; however, AChR pharmacology has been plagued by a lack of good receptor subtype-selective compounds. Mice lacking M3 mAChRs display intact cholinergically-mediated intestinal ion transport, suggesting a possible compensatory mechanism. Inflamed tissues often display perturbations in the enteric cholinergic system and reduced intestinal ion transport responses to cholinomimetics. The mechanism(s) underlying this hyporesponsiveness are not fully defined. Inflammation-evoked loss of mAChR-mediated control of epithelial ion transport in the mouse reveals a role for neuronal nicotinic AChRs, representing a hitherto unappreciated braking system to limit ACh-evoked Cl- secretion. We suggest that: i) pharmacological analyses should be supported by the use of more selective compounds and supplemented with molecular biology techniques targeting specific ACh receptors and signalling molecules, and ii) assessment of ion transport in normal tissue must be complemented with investigations of tissues from patients or animals with intestinal disease to reveal control mechanisms that may go undetected by focusing on healthy tissue only.
| S-EPMC2014671 | biostudies-other
Project description:Colorectal cancers (CRCs) are composed of an amalgam of cells with distinct genotypes and phenotypes. Here, we reveal a previously unappreciated heterogeneity in the biosynthetic capacities of CRC cells. We discover that the majority of ribosomal DNA transcription and protein synthesis in CRCs occurs in a limited subset of tumor cells that localize in defined niches. The rest of the tumor cells undergo an irreversible loss of their biosynthetic capacities as a consequence of differentiation. Cancer cells within the biosynthetic domains are characterized by elevated levels of the RNA polymerase I subunit A (POLR1A). Genetic ablation of POLR1A-high cell population imposes an irreversible growth arrest on CRCs. We show that elevated biosynthesis defines stemness in both LGR5+ and LGR5- tumor cells. Therefore, a common architecture in CRCs is a simple cell hierarchy based on the differential capacity to transcribe ribosomal DNA and synthesize proteins.
| S-EPMC9006079 | biostudies-literature
Project description:Saudi Arabia has no permanent lakes or rivers but has wet meadows, which are desert wetlands temporarily formed due to the seasonal rainfall. This work investigates the environmental variables' impact on the vegetation pattern in the desert-wetland ecosystem in Taif highlands. Forty-one stands were randomly selected representing three main habitats (wet meadows, slopes, and terraces) to study their floristic features and vegetation analysis. A total of 142 species were recorded belonging to 111 genera and 45 families in the desert wetlands of Taif Province. About 64.1% were natural plants, while 25.4% were segetal weeds, 7.7% were aquatic plants, and 2.8% were plants that escaped from cultivation. Therophytes dominated over the other life forms, and mono-regional taxa were the dominant chorotype. Multivariate analysis of the recorded plants produced eight vegetation groups; four of them (A: Potamogeton nodosus-Nasturtium officinale, B: Lemna gibba-Leptochloa fusca, C: Typha domingensis- Xanthium strumarium and D: Conyza stricta- Cyperus longus) represented the wet meadows, while two (E: Acacia gerrardii- Commicarpus plumbagineus and H: Osteospermum vaillantii- Eragrostis Pilosa) for slopes and other two (F: Argemone ochroleuca-Cyperus rotundus and G: Pulicaria undulata- Solanum incanum) for the desert terraces. The vegetation zonation was clear, which started from real aquatic species in the wet meadows passing through mixed vegetation in the slopes and ended with proper xerophytic vegetation in the terraces. Conyza stricta- Cyperus longus community had the highest species diversity, while that of Potamogeton nodosus-Nasturtium officinale had the lowest. The principal component analysis indicated that HCO3, NO3, Mg, Cl, Ca, and pH values were the most effective soil variable. The presence of several segetal weeds suggests the alteration of the natural status of the desert-wetland ecosystem, and thus the conservation of these natural habitats becomes urgent.
| S-EPMC8176040 | biostudies-literature
Project description:Members of the Ets transcription factor family are widely expressed in both the developing and mature mammalian intestine, but their biological functions remain primarily uncharacterized. We used a dominant repressor transgene approach to probe the function of epithelial Ets factors in the homeostasis of the crypt-villus unit, the functional unit of the small intestine. We show that targeted expression in small intestinal epithelium of a fusion protein composed of the Engrailed repressor domain and the Erm DNA-binding domain (En/Erm) results in marked disruption of normal crypt-villus homeostasis, including a cell-autonomous disturbance of epithelial maturation, increased epithelial transit, severe villus dysmorphogenesis, and crypt dysmorphogenesis. The epithelial maturation disturbance is independent of the regulation of TGFbetaRII levels, in contrast to Ets-mediated epithelial differentiation during development; rather, regulation of Cdx2 expression may play a role. The villus dysmorphogenesis is independent of alterations in the crypt-villus boundary and inappropriate beta-catenin activation, and thus appears to represent a new mechanism controlling villus architectural organization. An Analysis of animals mosaic for En/Erm expression suggests that crypt nonautonomous mechanisms underlie the crypt dysmorphogenesis phenotype. Our studies thus uncover novel Ets-regulated pathways of intestinal homeostasis in vivo. Interestingly, the overall En/Erm phenotype of disturbed crypt-villus homeostasis is consistent with recently identified Ets function(s) in the restriction of intestinal epithelial tumorigenesis.
| S-EPMC2671360 | biostudies-literature
Project description:Upwelling areas are shaped by enhanced primary production in surface waters, accompanied by a well-investigated planktonic succession. Although bacteria play an important role in biogeochemical cycles of upwelling systems, little is known about bacterial community composition and its development during upwelling events. The aim of this study was to investigate the succession of bacterial assemblages in aging upwelled water of the Benguela upwelling from coastal to offshore sites. Water from the upper mixed layer at 12 stations was sampled along two transects from the origin of the upwelling to a distance of 220 km. 16S rRNA gene amplicon sequencing was then used in a bacterial diversity analysis and major bacterial taxa were quantified by catalyzed reporter deposition-fluorescence in situ hybridization. Additionally, bacterial cell numbers and bacterial production were assessed. Community statistical analysis revealed a reproducible zonation along the two transects, with four clusters of significantly different microbial assemblages. Clustering was mainly driven by phytoplankton composition and abundance. Similar to the temporal succession that occurs during phytoplankton blooms in temperate coastal waters, operational taxonomic units (OTUs) affiliated with Bacteroidetes and Gammaproteobacteria were dominant during algal blooming whereas "Pelagibacterales" were highly abundant in regions with low algal abundance. The most dominant heterotrophic OTU (9% of all reads) was affiliated with "Pelagibacterales" and showed a strong negative correlation with phytoplankton. By contrast, the second most abundant heterotrophic OTU (6% of all reads) was affiliated with the phylum Verrucomicrobia and correlated positively with phytoplankton. Together with the close relation of bacterial production and phytoplankton abundance, our results showed that bacterial community dynamics is strongly driven by the development and composition of the phytoplankton community.
| S-EPMC4471433 | biostudies-literature