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A bespoke microfluidic pharmacokinetic compartment model for drug absorption using artificial cell membranes.

Early prediction of the rate and extent of intestinal absorption is vital for the efficient development of orally administered drugs. Here we show a new type of pharmacokinetic compartment model that shows a threefold improvement in the prediction of molecular absorption in the jejunum than the current state-of-the-art in vitro technique, parallel artificial membrane permeability assays (PAMPA). Our three-stage pharmacokinetic compartment model uses microfluidic droplets and bespoke, biomimetic artificial cells to model the path of a drug proxy from the intestinal space into the blood via an e

The gliadin p31-43 peptide: Inducer of multiple proinflammatory effects.

Coeliac disease (CD) is the prototype of an inflammatory chronic disease induced by food. In this context, gliadin p31-43 peptide comes into the spotlight as an important player of the inflammatory/innate immune response to gliadin in CD. The p31-43 peptide is part of the p31-55 peptide from α-gliadins that remains undigested for a long time, and can be present in the small intestine after ingestion of a gluten-containing diet. Different biophysical methods and molecular dynamic simulations have shown that p31-43 spontaneously forms oligomeric nanostructures, whereas experimental approaches us

Antisense transcription regulates the expression of the enterohemorrhagic Escherichia coli virulence regulatory gene ler in response to the intracellular iron concentration.

Enteric pathogens, such as enterohemorrhagic E. coli (EHEC) O157:H7, encounter varying concentrations of iron during their life cycle. In the gastrointestinal tract, the amount of available free iron is limited because of absorption by host factors. EHEC and other enteric pathogens have developed sophisticated iron-responsive systems to utilize limited iron resources, and these systems are primarily regulated by the Fur repressor protein. The iron concentration could be a signal that controls gene expression in the intestines. In this study, we explored the role of iron in LEE (locus for enter

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1).

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kid

Causes of malabsorption in the elderly.

The pathogenesis of malabsorption has been studied in 70 patients who presented over the age of 65 years and who were referred to a special investigative unit. Often more than one cause was apparent. Fourteen patients had pancreatic insufficiency, most of whom had no history of pain, alcoholism or gallstones. Twenty-three patients had the postgastrectomy syndrome or small-bowel diverticulosis or both. There were eight coeliacs aged 65-72 years at diagnosis. Fifteen patients had an anatomically normal small bowel; eight of these were over 80 years old, and 10 had vitamin B12 deficiency of whom

[Changes in the rat intestinal mucosa in hypervitaminosis A].

Administration of excess vitamin A to the growing male rats (50 000 IU of oily solution of retinol palmitate a day for 8 days) provoked a tendency toward a decrease in the number of goblet cells (of both absolute and relative number calculated per 500 cells of the epithelium) in the crypts and villi of the small intestinal mucosa, with this tendency being more marked in the inferior part of the intestine. At the same time administration of vitamin A excess increased the intensity of staining with alcyane blue of the secretion of the goblet cells, particularly on the apeces of the villi, which

Gliadin effect on the oxidative balance and DNA damage: An in-vitro, ex-vivo study.

BACKGROUND: Gliadins are involved in gluten-related disorders and are responsible for the alteration of the cellular redox balance. It is not clear if the gliadin-related oxidative stress can induce DNA damage in enterocytes. AIM: To investigate any possible genotoxicity caused by gliadin and to assess its relationship with oxidative stress in vitro and ex vivo. METHODS: Caco-2 cells were exposed for 6-12-24 h to increasing concentrations (250 μg/mL-1000 μg/mL) of digested gliadin. We investigated: cytotoxicity, oxidative balance (reactive oxygen species, ROS), DNA damage (comet assay and γ-…

Diagnostic and Research Aspects of Small Intestinal Disaccharidases in Coeliac Disease.

Disaccharidases (DS) are brush border enzymes embedded in the microvillous membrane of small intestinal enterocytes. In untreated coeliac disease (CD), a general decrease of DS activities is seen. This manuscript reviews different aspects of DS activities in CD: their utility in the diagnosis and their application to in vitro toxicity testing. The latter has never been established in CD research. However, with the recent advances in small intestinal organoid techniques, DS might be employed as a biomarker for in vitro studies. This includes establishment of self-renewing epithelial cells raise…

Cellular defects by deletion of ANO10 are due to deregulated local calcium signaling.

TMEM16K (ANO10) belongs to a family of ion channels and phospholipid scramblases. Mutations in ANO10 cause neurological and immunological defects, and abrogated ion transport. Here we show that Ano10 knockout in epithelial cells leads to defective ion transport, attenuated volume regulation and deranged Ca2+ signaling. Intestinal epithelial cells from Ano10 null mice are reduced in size and demonstrate an almost abolished spontaneous and TNFα-induced apoptosis. Similar defects were found in mouse peritoneal Ano10 null macrophages and in human THP1 macrophages with reduced ANO10 expression. A c

Short-term adaptation of rat intestine to ileostomy: implication for pediatric practice.

BACKGROUND: Surgical neonates with complex intestinal conditions, such as enterocolitis, midgut volvulus with bowel loss and multiple atresias, often require temporary stomas. Little is known on the postsurgical response of the altered gut segments, although adaptation is an important consideration in neonatal postoperative care, particularly after stoma closure. MATERIALS AND METHODS: Rats underwent bowel resection at a point 15 cm proximal to the ileocecal valve, and a split ileostomy was performed. On the 6th postoperative day the mucosal thickness was calculated with Soft Imaging System A

Intestinal microvillous atrophy in a patient with Down syndrome and aganglionic megacolon.

Intestinal microvillous disorders are an uncommon cause of severe diarrhea, with very poor prognosis. The authors report the case of a female infant with Down syndrome, aganglionic megacolon, severe diarrhea, and jejunal biopsy with ultrastructural changes consistent with microvillous atrophy. The patient condition improved after a colostomy performed in the setting of the treatment of Hirschprung disease.

Proliferation in the developing intestine is regulated by the endosomal protein Endotubin.

During postnatal intestinal development, the intestinal epithelium is highly proliferative, and this proliferation is regulated by signaling in the intervillous and crypt regions. This signaling is primarily mediated by Wnt, and requires membrane trafficking. However, the mechanisms by which membrane trafficking regulates signaling during this developmental phase are largely unknown. Endotubin (EDTB, MAMDC4) is an endosomal protein that is highly expressed in the apical endocytic complex (AEC) of villus enterocytes during fetal and postnatal development, and knockout of EDTB results in defecti…

Progressive intestinal tumor cell plasticity, Myc activation, and loss of Lgr5+ tumor stem cell lineage commitment upon Wnt depletion.

Plasticity, the capability of tumor cells to go through phenotypic transitions, promotes colorectal cancer (CRC) progression and treatment resistance. Although plasticity is evident in advanced CRCs, little is known about plasticity in early-stage tumors and tumor stem cells. Here, we demonstrate that a plastic cell state (PCS) is present already in polyps from patients with familial adenomatous polyposis and in mouse intestinal adenomas, in which PCS is associated with PROX1+ tumor stem cells. We furthermore analyzed progressive plasticity upon loss of the canonical wingless-related integrati

Enteral versus parenteral nutrition in auto-HCT: a randomized controlled trial on clinical outcomes and gut microbiome dynamics.

Disruption of the gut microbiome is a common consequence of chemotherapy, linked with detrimental treatment outcomes (e.g. sepsis), especially in haematopoietic stem cell transplant (HCT) recipients. Preclinical data suggest that enteral nutrition (EN) is superior to parenteral nutrition (TPN), minimising gut atrophy and promoting eubiosis; yet, TPN continues to be used. Here, we evaluated the clinical effects of EN and TPN in autologous HCT recipients and their influence on gut microbiome dynamics. Despite efforts to optimise delivery, EN was poorly tolerated and ultimately proved unfeasible.

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… It is an amino acid exclusively produced by enterocytes; hence, when enterocyte mass is decreased (in the case of GI-M), plasma citrulline levels are also detectably decreased. …

Mucosal Bacterial Immunotherapy Attenuates the Development of Experimental Colitis by Reducing Inflammation Through the Regulation of Myeloid Cells.

Ulcerative colitis is a chronic relapsing-remitting and potentially progressive form of inflammatory bowel disease in which there is extensive inflammation and mucosal damage in the colon and rectum as a result of an abnormal immune response. MV130 is a mucosal-trained immunity-based vaccine used to prevent respiratory tract infections in various clinical settings. Additionally, MV130 may induce innate immune cells that acquire anti-inflammatory properties and promote tolerance, which could have important implications for chronic inflammatory diseases such as ulcerative colitis. This work demo

Physiology, leptin gene expression, and intestinal morphology of pinhead and starved milkfish (Chanos chanos).

"Pinhead" is an abnormal condition of farmed fish which is rarely studied, albeit well known among fish culturists, and is characterized by extreme emaciation and anorexia. In this study, the potential impacts of pinhead condition in milkfish were analyzed and compared to fed, healthy, and a group starved for four weeks. The condition factor and hepatosomatic index of pinhead milkfish were significantly lower compared with fed, healthy individuals. Abnormal plasma osmolality and muscle water content in pinhead milkfish indicated an imbalance in their internal water content. The anorexigenic ho

Visualization of Differentiated Cells in 3D and 2D Intestinal Organoid Cultures.

The intestinal epithelium maintains self-renewal and differentiation capacities via coordination of key signaling pathways, including the Wnt, bone morphogenetic protein (BMP), epidermal growth factor (EGF), and Notch signaling pathways. Based on this understanding, a combination of stem cell niche factors, EGF, Noggin, and the Wnt agonist R-spondin was shown to enable the growth of mouse intestinal stem cells and the formation of organoids with indefinite self-renewal and full differentiation capacity. Two small-molecule inhibitors, including a p38 inhibitor and a TGF-beta inhibitor, were add

Lactose-Gated Mesoporous Silica Particles for Intestinal Controlled Delivery of Essential Oil Components: An In Vitro and In Vivo Study.

Mesoporous silica microparticles functionalized with lactose for the specific release of essential oil components (EOCs) in the small intestine are presented. In vitro and in vivo intestinal models were applied to validate the microparticles (M41-EOC-L), in which the presence of lactase acts as the triggering stimulus for the controlled release of EOCs. Among the different microdevices prepared (containing thymol, eugenol and cinnamaldehyde), the one loaded with cinnamaldehyde showed the most significant Caco-2 cell viability reduction. On the other hand, interaction of the particles with ente

PNU-282987 Attenuates Intestinal Epithelial Barrier Dysfunction in LPS-Induced Endotoxemia.

PNU-282987, the α7 acetylcholine receptor(α7nAchR) agonist, has been repeatedly reported to play a key role in anti-inflammatory action of multiple disease. However, little is known about its effect on LPS-induced intestinal epithelial barrier dysfunction. This study investigated the protective effects and mechanisms of PNU-282987 on intestinal epithelial barrier dysfunction in lipopolysaccharide(LPS)-induced endotoxemic rats. Endotoxemia models were induced by intraperitoneal injection of 10 mg/kg LPS. In the endotoxemic group, results showed increases in ileum mucosal permeability, ultrastru

The Role of Gastrointestinal-Related Fatty Acid-Binding Proteins as Biomarkers in Gastrointestinal Diseases.

The fatty acid-binding proteins play a major role in intracellular transportation of long-chain fatty acids. Nine fatty acid-binding proteins have been identified, with each having individual tissue-specific functions in addition to regulation of fatty acids. This review focuses on the three fatty acid-binding proteins found in the gastrointestinal tract and discusses their role as diagnostic or disease monitoring markers in neonatal necrotizing enterocolitis, acute mesenteric ischemia, celiac disease, and inflammatory bowel disease. Of these three fatty acid-binding proteins, intestinal fatty