Precision-cut Intestinal Slices Research Articles

Precision-cut rat, mouse, and human intestinal slices as novel models for the early-onset of intestinal fibrosis

Intestinal fibrosis (IF) is a major complication of inflammatory bowel disease. IF research is limited by the lack of relevant in vitro and in vivo models. We evaluated precision-cut intestinal slices (PCIS) prepared from human, rat, and mouse intestine as ex vivo models mimicking the early-onset of (human) IF. Precision-cut intestinal slices prepared from human (h), rat (r), and mouse (m) jejunum, were incubated up to 72 h, the viability of PCIS was assessed by ATP content and morphology, and the gene expression of several fibrosis markers was determined. The viability of rPCIS decreased after 24 h of incubation, whereas mPCIS and hPCIS were viable up to 72 h of culturing. Furthermore, during this period, gene expression of heat shock protein 47 and plasminogen activator inhibitor 1 increased in all PCIS in addition to augmented expression of synaptophysin in hPCIS, fibronectin (Fn2) and TGF-β1 in rPCIS, and Fn2 and connective tissue growth factor (Ctgf) in mPCIS. Addition of TGF-β1 to rPCIS or mPCIS induced the gene expression of the fibrosis markers Pro-collagen1a1, Fn2, and Ctgf in both species. However, none of the fibrosis markers was further elevated in hPCIS. We successfully developed a novel ex vivo model that can mimic the early-onset of fibrosis in the intestine using human, rat, and mouse PCIS. Furthermore, in rat and mouse PCIS, TGF-β1 was able to even further increase the gene expression of fibrosis markers. This indicates that PCIS can be used as a model for the early-onset of IF.

P078. Evaluating the efficacy of potential drugs for intestinal fibrosis using precision-cut tissue slices

Intestinal fibrosis (IF) is a common complication in Crohn's disease. Currently, there are no drugs registered to treat IF and the sole therapy is intestinal resection. Transforming growth factor (TGF)-beta and platelet-derived growth factor (PDGF) play a key role in IF and are the main targets for potential treatment. Recently, we developed a novel model for the early onset of IF using precision-cut intestinal slices (PCIS). Our objective was to investigate the antifibrotic effect of some potential antifibrotic compounds, including TGF-beta and PDGF-pathway inhibitors, by using the murine PCIS fibrosis model. Murine PCIS were incubated up to 48 h. The viability was assessed by evaluating the ATP content of the PCIS. Gene expression of the fibrosis markers pro-collagen 1a1 (Col1a1), heat shock protein 47 (Hsp47) and fibronectin (Fn2) were determined by qPCR. The effects of antifibrotic drugs mainly inhibiting the TGF-beta pathway: valproic acid (VPA), tetrandrine (Tet), pirfenidone (Pir), and LY2109761 (LY) and mainly inhibiting the PDGF pathway: imatinib (Ima), sorafenib (Sor), and sunitinib (Sun) were determined at the maximal non-toxic concentrations. Murine PCIS remained viable up to 48 h of incubation and showed increased gene expression of the fibrosis markers (Col1a1, 0.6; Hsp47, 4.0 and Fn2, 4.4 fold). After 48 h, VPA and Tet down-regulated Hsp47 gene expression 2.0 and 1.7 fold, respectively. Furthermore, Fn2 gene expression was also decreased 2.1 fold by Tet. Meanwhile, Pir decreased Col1a1, Hsp47, and Fn2 gene expression 2.2, 1.5, and 1.2 fold, respectively. All investigated markers of fibrosis were down-regulated by LY (Col1a1, 9.0; Hsp47, 1.9 and Fn2, 2.7 fold). Sun decreased the expression of Col1a1, 1.6; Hsp47, 3.3 and Fn2, 2.3 fold, while Sor only down-regulated Hsp47, 1.3 fold. In contrast, Ima did not affect the expression of fibrosis markers. From the compounds studied, the TGF-beta-inhibitors; Tet, Pir, and LY and only one PDGF-inhibitor, Sun, showed potential antifibrotic effect on gene expression of fibrosis markers in murine PCIS. Thus, PCIS is a promising model to evaluate the antifibrotic effect of potential drugs for intestinal fibrosis.

Precision-cut intestinal slices as a culture system to analyze the infection of differentiated intestinal epithelial cells by avian influenza viruses

Many viruses infect and replicate in their host via the intestinal tract, e.g. many picornaviruses, several coronaviruses and avian influenza viruses of waterfowl. To analyze infection of enterocytes is a challenging task as culture systems for differentiated intestinal epithelial cells are not readily available and often have a life span that is too short for infection studies. Precision-cut intestinal slices (PCIS) from chicken embryos were prepared and shown that the epithelial cells lining the lumen of the intestine are viable for up to 4 days. Using lectin staining, it was demonstrated that α2,3-linked sialic acids, the preferred receptor determinants of avian influenza viruses, are present on the apical side of the epithelial cells. Furthermore, the epithelial cells (at the tips) of the villi were shown to be susceptible to infection by an avian influenza virus of the H9N2 subtype. This culture system will be useful to analyze virus infection of intestinal epithelial cells and it should be applicable also to the intestine of other species.

Consequences of Mrp2 deficiency for diclofenac toxicity in the rat intestine ex vivo

The non-steroidal anti-inflammatory drug diclofenac (DCF) has a high prevalence of intestinal side effects in humans and rats. It has been reported that Mrp2 transporter deficient rats (Mrp2−) are more resistant to DCF induced intestinal toxicity. This was explained in vivo by impaired Mrp2-dependent biliary transport of DCF-acylglucuronide (DAG), leading to decreased intestinal exposure to DAG and DCF. However, it is not known to what extent adaptive changes in the Mrp2− intestine itself influence its sensitivity to DCF toxicity without the influence of liver metabolites. To investigate this, DCF toxicity and disposition were studied ex vivo by precision-cut intestinal slices and Ussing chamber using intestines from wild type (WT) and Mrp2− rats. The results show that adaptive changes due to Mrp2 deficiency concerning Mrp2, Mrp3 and BCRP gene expression, GSH content and DAG formation were different between liver and intestine. Furthermore, Mrp2− intestine was intrinsically more resistant to DCF toxicity than its WT counterpart ex vivo. This can at least partly be explained by a reduced DCF uptake by the Mrp2− intestine, but is not related to the other adaptive changes in the intestine. The extrapolation of this data to humans with MRP2 deficiency is uncertain due to species differences in activity and regulation of transporters.

Precision cut intestinal slices are an appropriate ex vivo model to study NSAID-induced intestinal toxicity in rats

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used therapeutic agents, however, they are associated with a high prevalence of intestinal side effects. In this investigation, rat precision cut intestinal slices (PCIS) were evaluated as an ex vivo model to study NSAID-induced intestinal toxicity.Firstly, PCIS were incubated with 0–200μM diclofenac (DCF), one of the most intensively studied NSAIDs, to investigate whether they could correctly reflect the toxic mechanisms. DCF induced intestinal toxicity in PCIS was shown by morphological damage and ATP depletion. DCF induced endoplasmic-reticulum (ER) stress, mitochondrial injury and oxidative stress were reflected by up-regulated HSP-70 (heat shock protein 70) and BiP (binding immunoglobulin protein) gene expression, caspase 9 activation, GSH (glutathione) depletion and HO-1 (heme oxygenase 1) gene up-regulation respectively. Furthermore, DCF intestinal metabolites, which gave rise to protein adduct but not toxicity, were detected in PCIS.Secondly, PCIS were incubated with various concentrations of five NSAIDs. Typical NSAID-induced morphological changes were observed in PCIS. The ex vivo toxicity ranking (diflunisal>diclofenac=indomethacin>naproxen≫aspirin) showed good correlation with published in vitro and in vivo data, with diflunisal being the only exception.In conclusion, PCIS correctly reflect the various mechanisms of DCF-induced intestinal toxicity, and can serve as an ex vivo model for the prediction of NSAID-induced intestinal toxicity.

Diclofenac toxicity in human intestine ex vivo is not related to the formation of intestinal metabolites.

The use of diclofenac (DCF), a nonsteroidal anti-inflammatory drug, is associated with a high prevalence of gastrointestinal side effects. In vivo studies in rodents suggested that reactive metabolites of DCF produced by the liver or the intestine might be responsible for this toxicity. In the present study, precision-cut intestinal slices (PCIS) prepared from the jejunum of 18 human donors were used as an ex vivo model to investigate whether DCF intestinal metabolites are responsible for its intestinal toxicity in man. PCIS were incubated with a concentration range of DCF (0-600 µM) up to 24 h. DCF (≥400 µM) caused direct toxicity to the intestine as demonstrated by ATP depletion, morphological damage, caspase 3 activation, and lactate dehydrogenase leakage. Three main metabolites produced by PCIS (4'-hydroxy DCF, 5-hydroxy DCF, and DCF acyl glucuronide) were detected by HPLC. Protein adducts were detected by immunohistochemical staining and showed correlation with the intestinal metabolites. DCF induced similar toxicity to each of the samples regardless of the variation in metabolism among them. Less metabolites were produced by slices incubated with 400 µM DCF than with 100 µM DCF. The addition of the metabolic inhibitors such as ketoconazole, cimetidine, or borneol decreased the metabolite formation but increased the toxicity. The results suggest that DCF can induce intestinal toxicity in human PCIS directly at therapeutically relevant concentrations, independent of the reactive metabolites 4'-OH DCF, 5-OH DCF, or diclofenac acylglucuronide produced by the liver or formed in the intestine.

Precision-cut intestinal slices as an in vitro model to predict NSAID induced intestinal toxicity

Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with high prevalence of gastro-intestinal side-effects. In vivo studies suggest that uncoupling of oxidative phosphorylation is an important cause of the toxicity and that the toxicity is aggravated by enterohepatic circulation. Precision-cut intestinal slices (PCIS) are a newly established in vitro model with intact architecture of the intestine, preserved viability and metabolism during incubation up to 24 h. In this study, this model is used to predict NSAID-induced intestinal toxicity. PCIS from rat jejunum were incubated for 5 h with a concentration range of 5 NSAIDs: diflunisal (0.05-1 mM), indomethacin (0.05-1 mM), diclofenac (0.05-1 mM), naproxen (0.1-5mM) and aspirin (0.1-10 mM). Toxicity was assessed by the ATP content. In vitro TC50 of these 5 compounds was calculated and compared with in vivo TC50 and the mitochondrial toxicity data as reported in the literature. Based on TC50 values, toxicity ranking in the present study appeared to be: aspirin (>10mM)> naproxen (2.96mM)> diclofenac (0.29mM)> indomethacin (0.29mM)> diflunisal (0.18 mM). This is very well in line with the reported toxicity ranking found with the isolated mitochondria. When compared with the in vivo TC50, only one exception of diflunisal was found, which appeared highly toxic in vitro whereas in vivo it's one of the least toxic compound. This discrepancy could not yet be explained by in vivo toxicokinetic factors (absorbtion, enterohepatic circulation, metabolism, excretion). In conclusion, both intrinsic (mitochondrial) toxicity as well as in vivo toxicity ranking are well predicted by the PCIS model.

Nanoparticle Formulation of a Poorly Soluble Cannabinoid Receptor 1 Antagonist Improves Absorption by Rat and Human Intestine

The inclusion of nanoparticles dispersed in a hydrophilic matrix is one of the formulation strategies to improve the bioavailability of orally administered Biopharmaceutics Classification System (BCS) class II and IV drugs by increasing their dissolution rate in the intestine. To confirm that the increased dissolution rate results in increased bioavailability, in vitro and in vivo animal experiments are performed, however, translation to the human situation is hazardous. In this study, we used a range of in vitro and ex vivo methods, including methods applying human tissue, to predict the in vivo oral bioavailability of a model BCS class II CB-1 antagonist, formulated as a nanoparticle solid dispersion. The enhanced dissolution rate from the nanoparticle formulation resulted in an increased metabolite formation in both rat and human precision-cut intestinal slices, suggesting increased uptake and intracellular drug concentration in the enterocytes. In Ussing chamber experiments with human tissue, both the metabolite formation and apical efflux of the metabolite were increased for the nanoparticulate solid dispersion compared with a physical mixture, in line with the results in intestinal slices. The pharmacokinetics of the different formulations was studied in rats in vivo. The nanoparticle formulation indeed improved the absorption of the cannabinoid receptor 1 (CB-1) antagonist and the delivery into the brain compared with the physical mixture. In conclusion, the combined approach provides a valuable set of tools to investigate the effects of formulation on the absorption of poorly soluble compounds in human intestine and may provide relevant information on the oral bioavailability in humans early in the development process.

Precision-cut Intestinal Slices as In Vitro Tool for Studies on Drug Metabolism

Precision-cut Intestinal Slices as In Vitro Tool for Studies on Drug Metabolism

Precision-cut Intestinal Slices as In Vitro Tool for Studies on Drug Metabolism

The role of the intestine in drug metabolism has long been underestimated as a consequence of the technical difficulty to discern the role of the intestine from that of the liver in in vivo experiments and of the lack of in vitro models that are sufficiently viable and fully representing the physiology and anatomy of the intestine. Recently the precision-cut slice model, which is widely used for liver and kidney, was also adapted for the small and large intestine. In this review the application of precision-cut intestinal slices (PCIS) for research in drug metabolism and transport is discussed. PCIS can be prepared from animal and human tissues from all regions of the intestine allowing investigation of species differences and regional gradients of activities of metabolizing enzymes. They are viable for 8-24 h of incubation and show high activity of drug metabolizing enzymes, representative for the in vivo activity. They have been successfully used to study drug-drug interactions such as induction, inhibition and regulation of drug metabolizing enzymes, transporters and nuclear factors. Moreover they appear to be a suitable model for studies on cold preservation of donor organs for transplantation, and allow exploring inter-organ interactions by co-incubation with precision-cut slices of other organs. Their application as model for drug-induced intestinal toxicity is still in its infancy but appears to be promising. PCIS, prepared from human and animal tissues, represent a powerful translational model for drug metabolism, transport and toxicity studies and as such contributes to the reduction and replacement of animal experiments.

Precision-cut Intestinal Slices as In Vitro Tool for Studies on Drug Metabolism

The role of the intestine in drug metabolism has long been underestimated as a consequence of the technical difficulty to discern the role of the intestine from that of the liver in in vivo experiments and of the lack of in vitro models that are sufficiently viable and fully representing the physiology and anatomy of the intestine. Recently the precision-cut slice model, which is widely used for liver and kidney, was also adapted for the small and large intestine. In this review the application of precision-cut intestinal slices (PCIS) for research in drug metabolism and transport is discussed. PCIS can be prepared from animal and human tissues from all regions of the intestine allowing investigation of species differences and regional gradients of activities of metabolizing enzymes. They are viable for 8-24 h of incubation and show high activity of drug metabolizing enzymes, representative for the in vivo activity. They have been successfully used to study drug-drug interactions such as induction, inhibition and regulation of drug metabolizing enzymes, transporters and nuclear factors. Moreover they appear to be a suitable model for studies on cold preservation of donor organs for transplantation, and allow exploring inter-organ interactions by co-incubation with precision-cut slices of other organs. Their application as model for drug-induced intestinal toxicity is still in its infancy but appears to be promising. PCIS, prepared from human and animal tissues, represent a powerful translational model for drug metabolism, transport and toxicity studies and as such contributes to the reduction and replacement of animal experiments.

Rat intestinal precision-cut slices as an in vitro model to study xenobiotic interaction with transporters

ATP-binding cassette (ABC) proteins play key role in tissue defence by transporting metabolic waste and toxic chemicals out of the cells. Consequently, intact cell systems are required to study xenobiotic interactions with ATP-dependent transporters. The aim of the present study was to set up an intestinal precision-cut slice technique to study the interactions of ABC transporters with xenobiotics. Rat intestinal slices were incubated with verapamil, indomethacin and glibenclamide, and the ability of the above-mentioned drugs to inhibit the multidrug resistance glycoprotein (MDR) and/or multidrug-resistance-associated protein (MRP) was assessed by measuring the intracellular conversion of calcein-AM to fluorescent calcein. The ABC transporters’ inhibitors caused a time-dependent florescence increase which reached the maximum value at 30 min. Verapamil and glibenclamide promoted a concentration-dependent intracellular accumulation of calcein (IC 50 8.1 × 10 −6 M, 1.9 × 10 −4 M, respectively). The effect of glibenclamide was fully reversed by washing the slices, suggesting the reversible nature of calcein accumulation. These data suggest that the precision-cut intestinal slices are a reliable, simple and fast system to evaluate xenobiotic interactions with ABC transporters in rat and, hopefully, in human intestine.

Precision-Cut Slices as a Tool for Studying Phase II Drug Metabolism in Rat Small Intestine in Vitro

ABSTRACTA wide range of endogenous and exogenous compounds including many drugs and their metabolites are inactivated by phase II drug metabolism enzymes UDP-glucuronyltransferase and glutathione S-transferase. The aim of the study was to set up an intestinal precision-cut slice technique for evaluating phase II drug metabolism in rat small intestine. The enzyme activity of UDP-glucuronyltransferase and glutathione S-transferase was measured up to 4 h of incubation and compared with those from intestinal cells obtained by mucosa scraping technique. The results from our study suggest that the activity of both phase II drug metabolism enzymes remains constant at least for a period of 4 h. Both intestinal preparations exhibit phase II metabolic activities at similar rates, but precision-cut intestinal slices have a longer life span. They remain viable up to 24 h of incubation. Precision cut slices might be reliable and quite simple system for evaluating xenobiotic phase II metabolism in rat intestine in vitro.

A microfluidic approach for in vitro assessment of interorgan interactions in drug metabolism using intestinal and liver slices

Over the past two decades, it has become increasingly clear that the intestine, in addition to the liver, plays an important role in the metabolism of xenobiotics. Previously, we developed a microfluidic-based in vitro system for the perifusion of precision-cut liver slices for metabolism studies. In the present study, the applicability of this system for the perifusion of precision-cut intestinal slices, and for the sequential perifusion of intestinal and liver slices, all from rat, was tested to mimic the in vivo first pass situation. Intestinal and liver slices, exposed to the substrates 7-ethoxycoumarin (7-EC), 7-hydroxycoumarin (7-HC) and lidocaine (Li), exhibited similar metabolic rates in the biochip and in the well plates for periods of at least 3 h. The metabolic rate remained the same when two slices were placed in adjacent microchambers and perifused sequentially. In addition, the system has been adapted to sequentially perifuse intestinal and liver tissue slices in a two-compartment co-culture perfusion system with a continuous flow of medium. It becomes possible to direct metabolites or other excreted compounds formed by an intestinal slice in the first compartment to the second compartment containing a liver slice. The intestine does not influence liver metabolism for these substrates. The interplay between these two organs was demonstrated by exposing the slices to the primary bile acid, chenodeoxycholic acid (CDCA). CDCA induced the expression of fibroblast growth factor 15 (FGF15) in the intestinal slice, which resulted in a stronger down-regulation of the enzyme, cytochrome P450 7A1 (CYP7A1), in the liver slice in the second compartment than when the liver slice was exposed to CDCA in a single-microchamber biochip. We thus demonstrate in this paper that intestinal slices, in addition to liver slices, remain functional in the biochip under flow conditions, and that the two-microchamber biochip has great potential for the study of interorgan effects. This is the first example of the incorporation of both liver and intestinal slices in a microfluidic device. Use of this microfluidic system will improve our insight into interorgan interactions and elucidate as yet unknown mechanisms involved in toxicity, gene regulation and drug-drug interactions.