Search results for "CACO-2 CELLS"
showing 10 items of 170 documents
The Insulin Receptor Substrate 1 (Irs1) in Intestinal Epithelial Differentiation and in Colorectal Cancer
2012
Colorectal cancer (CRC) is associated with lifestyle factors that affect insulin/IGF signaling, of which the insulin receptor substrate 1 (IRS1) is a key transducer. We investigated expression, localization and pathologic correlations of IRS1 in cancer-uninvolved colonic epithelium, primary CRCs with paired liver metastases and in vitro polarizing Caco2 and HT29 cells. IRS1 mRNA and protein resulted higher, relative to paired mucosa, in adenomas of familial adenomatous polyposis patients and in CRCs that overexpressed c-MYC, ß-catenin, InsRß, and IGF1R. Analysis of IRS1 immunostaining in 24 cases of primary CRC with paired colonic epithelium and hepatic metastasis showed that staining inten…
Induction of the fatty acid transport protein 1 and acyl-CoA synthase genes by dimer-selective rexinoids suggests that the peroxisome proliferator-ac…
2000
The intracellular fatty acid content of insulin-sensitive target tissues determines in part their insulin sensitivity. Uptake of fatty acids into cells is a controlled process determined in part by a regulated import/export system that is controlled at least by two key groups of proteins, i.e. the fatty acid transport protein (FATP) and acyl-CoA synthetase (ACS), which facilitate, respectively, the transport of fatty acids across the cell membrane and catalyze their esterification to prevent their efflux. Previously it was shown that the expression of the FATP-1 and ACS genes was controlled by insulin and by peroxisome proliferator-activated receptor (PPAR) agonists in liver or in adipose t…
Chitosan-coated mesoporous MIL-100(Fe) nanoparticles as improved bio-compatible oral nanocarriers
2017
Nanometric biocompatible Metal-Organic Frameworks (nanoMOFs) are promising candidates for drug delivery. Up to now, most studies have targeted the intravenous route, related to pain and severe complications; whereas nanoMOFs for oral administration, a commonly used non-invasive and simpler route, remains however unexplored. We propose here the biofriendly preparation of a suitable oral nanocarrier based on the benchmarked biocompatible mesoporous iron(III) trimesate nanoparticles coated with the bioadhesive polysaccharide chitosan (CS). This method does not hamper the textural/structural properties and the sorption/release abilities of the nanoMOFs upon surface engineering. The interaction …
Current-Driven Organic Electrochemical Transistors for Monitoring Cell Layer Integrity with Enhanced Sensitivity
2021
In this progress report an overview is given on the use of the organic electrochemical transistor (OECT) as a biosensor for impedance sensing of cell layers. The transient OECT current can be used to detect changes in the impedance of the cell layer, as shown by Jimison et al. To circumvent the application of a high gate bias and preventing electrolysis of the electrolyte, in case of small impedance variations, an alternative measuring technique based on an OECT in a current-driven configuration is developed. The ion-sensitivity is larger than 1200 mV V-1 dec-1 at low operating voltage. It can be even further enhanced using an OECT based complementary amplifier, which consists of a p-type a…
Monitoring of Cell Layer Integrity with a Current-Driven Organic Electrochemical Transistor
2019
Abstract The integrity of CaCo-2 cell barriers is investigated by organic electrochemical transistors (OECTs) in a current-driven configuration. Ion transport through cellular barriers via the paracellular pathway is modulated by tight junctions between adjacent cells. Rupturing its integrity by H2O2 is monitored by the change of the output voltage in the transfer characteristics. It is demonstrated that by operating the OECT in a current-driven configuration, the sensitive and temporal resolution for monitoring the cell barrier integrity is strongly enhanced as compared to the OECT transient response measurement. As a result, current-driven OECTs are useful tools to assess dynamic and crit…
Evaluation of the cytotoxic effect of 7keto-stigmasterol and 7keto-cholesterol in human intestinal (Caco-2) cells
2012
The biological implications of cholesterol oxidation products have been investigated, though research on plant sterol oxidation products is scarce and in some cases contradictory. The cytotoxicity of 7keto(k)-stigmasterol versus 7keto(k)-cholesterol at different concentrations (0-120 μM) and incubation times (4-24h), in intestinal epithelial cells (Caco-2 cells) was evaluated. The 3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyl tetrazolium bromide and neutral red uptake tests, mitochondrial membrane potential (ΔΨm), and relative DNA and RNA contents in the cell cycle phases were determined. Possible interaction effects between 7k-derivatives or non-oxidized stigmasterol were monitored. Endo/lysos…
Protective effect of bioaccessible fractions of citrus fruit pulps against H2O2-induced oxidative stress in Caco-2 cells
2017
Fruit pulps from Navel (N) and Cara Cara (CC) oranges, and Clementine mandarin freshly harvested (M) and refrigerated stored (M12) were used to evaluate the cytoprotective effect of their bioaccessible fractions (BF) against H2O2-induced oxidative stress in Caco-2 cells. BF of samples preserved viability vs. H2O2 treated cells, reaching values similar to controls. Lipid peroxidation was reduced to levels of control cells, but M did not reach control values. ROS and mitochondrial membrane potential changes (Δψm) values were reduced compared with H2O2 treated cells, but without achieving control levels. A significant reduction in cell proportions in G1 phase and a significant increase in sub-…
Truncated internalin A and asymptomatic Listeria monocytogenes carriage: in vivo investigation by allelic exchange
2004
ABSTRACT Allelic exchange of the region coding for the C terminus of InlA between one epidemic (with an 80-kDa InlA) and one asymptomatic (with a 47-kDa InlA) carriage Listeria monocytogenes strain confirmed the need for this region for internalin entry in vitro. Interestingly, restoration of internalin A functionality did not result in full virulence in chicken embryo assays.
Modulation of drug transport by selected flavonoids: Involvement of P-gp and OCT?
2004
Flavonoids, as a common component of daily nutrition, are a possible source of interference with absorption processes, due to modulation of transporting proteins. In this study, the influence of selected flavonoids (quercetin, isoquercitrin, spiraeoside, rutin, kaempferol, naringenin, naringin, and kaempferol) on the transport of the P-gp substrate [3H]talinolol across Caco-2 cell monolayers was investigated. To elucidate the mechanism behind the interaction observed in this system the potency of the flavonoids to replace [3H]talinolol from its P-gp binding site as well as their activity to inhibit OCT2-mediated [14C]TEA uptake into LLC-PK(1) cells were measured, as P-gp and OCT have been s…
Protective effect of antioxidants contained in milk-based fruit beverages against sterol oxidation products
2017
Abstract Sterol oxidation products (SOPs) have shown cytotoxic effect in human intestinal cells; however, their effect within a food matrix has not been assayed yet. This study evaluated the possible cytotoxic effect of SOPs within bioaccessible fractions (BFs) of two milk-based fruit beverages with (BFA)/without (BFB) plant sterols in differentiated Caco-2 cells and if the BFs counteracted the cytotoxic effect induced by COPs mixture (30 and 60 μM). BFs did not evoke cytotoxic effect in any of the tests carried out and they protected against the loss of intestinal cohesion, mitochondrial depolarization and necrosis induced by COPs mixture. Moreover, BFB sample protected from cell cycle arr…