Specific protein supplementation using soya, casein or whey differentially affects regional gut growth and luminal growth factor bioactivity in rats; implications for the treatment of gut injury and stimulating repair.

Modulation of regional growth within specific segments of the bowel may have clinical value for several gastrointestinal conditions. We therefore examined the effects of different dietary protein sources on regional gut growth and luminal growth factor bioactivity as potential therapies. Rats were fed for 14 days on isonitrogenous and isocaloric diets comprising elemental diet (ED) alone (which is known to cause gut atrophy), ED supplemented with casein or whey or a soya protein-rich feed.

Quantification of epithelial cell proliferation, cell dynamics, and cell kinetics in vivo.

The measurement of cell proliferation in vivo is usually carried out by the examination of static measures. These comprise the mitotic index or labeling indices using incorporation of DNA synthesis markers such as bromodeoxyuridine or tritiated thymidine, or intrinsic markers, such as Ki67 and proliferative cell nuclear antigen (PCNA). But static measures only provide a 'snapshot' of cell proliferation.

A Simple Device to Rapidly Prepare Whole Mounts of the Mouse Intestine.

Preparing whole mounts of the mouse small intestine and colon for subsequent analysis or quantification can be time consuming and difficult. We describe the use of a simple device to cut and 'roll' mouse intestines to rapidly prepare whole mount preparations of superior and uniform quality to that which can be achieved by hand. The device comprises a base that holds 4 stainless steel rods and a top, which acts a cutting guide.

Epidermal growth factor attenuates tubular necrosis following mercuric chloride damage by regeneration of indigenous, not bone marrow-derived cells.

To assess effects of epidermal growth factor (EGF) and pegylated granulocyte colony-stimulating factor (P-GCSF; pegfilgrastim) administration on the cellular origin of renal tubular epithelium regenerating after acute kidney injury initiated by mercuric chloride (HgCl2 ). Female mice were irradiated and male whole bone marrow (BM) was transplanted into them. Six weeks later recipient mice were assigned to one of eight groups: control, P-GCSF+, EGF+, P-GCSF+EGF+, HgCl2 , HgCl2 +P-GCSF+, HgCl2 +EGF+ and HgCl2 +P-GCSF+EGF+.

Inhibition of Aurora-B kinase activity confers antitumor efficacy in preclinical mouse models of early and advanced gastrointestinal neoplasia.

The Aurora family of kinases, play a fundamental role in cell division and are overexpressed in several cancers including colon. The activity of barasertib-hQPA, a selective inhibitor of Aurora-B kinase (ABK) was investigated in a range of preclinical models of gastrointestinal cancer. Treatment with barasertib-hQPA produced anti-proliferative and cytotoxic effects across a panel of human colorectal cancer (CRC) cell lines in vitro.

Effects of vandetanib on adenoma formation in a dextran sodium sulphate enhanced Apc(MIN/+) mouse model.

The Apc(MIN/+) mouse is a well-characterised model of intestinal tumourigenesis in which animals develop macroscopically detectable adenomas. However, most of the adenomas are formed in the small intestine and resolution of events in the colon, the most relevant site for human disease, is limited. Inducing colitis with dextran sodium sulphate (DSS) can selectively enhance the development of lesions in the colon.

Reduced susceptibility to azoxymethane-induced aberrant crypt foci formation and colon cancer in growth hormone deficient rats.

Objectives: To evaluate the role of GH in colon carcinogenesis, we examined the formation of aberrant crypt foci (ACFs) and tumor development in wild type (WT) and GH-deficient, spontaneous dwarf rats (SDRs) exposed to the carcinogen azoxymethane (AOM).

Design: ACF were quantified by stereomicroscopy and tumor number and weights were recorded for each animal. Cell proliferation was measured by vincristine metaphase arrest, flow cytometry, and bromodeoxyuridine (BrdU) incorporation.

Detection of metabolic alterations in non-tumor gastrointestinal tissue of the Apc(Min/+) mouse by (1)H MAS NMR spectroscopy.

In this study, we have used metabolic profiling (metabolomics/metabonomics) via high resolution magic angle spinning (HRMAS) and solution state (1)H NMR spectroscopy to characterize small bowel and colon tissue from the Apc(Min/+) mouse model of early gastrointestinal (GI) tumorigenesis. Multivariate analysis indicated the presence of metabolic differences between the morphologically normal/non-tumor tissue from approximately 10 week-old Apc(Min/+) mice and their wild-type litter mates. The metabolic profile of isolated lamina propria and epithelial cells from the same groups could also be discriminated on the basis of genotype.

Involvement of KLF4 in sulforaphane- and iberin-mediated induction of p21(waf1/cip1).

Sulforaphane (SF; 4-methylsulfinylbutyl isothiocyanate), a dietary compound derived from broccoli, may exhibit chemopreventive properties by inducing cell cycle arrest via induction of cyclin-dependent kinase inhibitor 1A (p21(waf1/cip1)), but the exact molecular mechanism has not been determined. Here we evaluate the role of the transcription factor Kruppel-like factor 4 (KLF4) in mediating the induction of p21(waf1/cip1) and cellular differentiation by SF and iberin (IB; 3-methylsulphinyl propyl isothiocyanate), also derived from broccoli. Exposure of Caco-2 and Caco-2/TC7 cells to SF and IB increased expression of both KLF4 and p21(waf1/cip1), whereas exposure of HT29 cells resulted only in induction of p21(waf1/cip1).

Ectopic expression of P-cadherin correlates with promoter hypomethylation early in colorectal carcinogenesis and enhanced intestinal crypt fission in vivo.

P-cadherin is normally expressed in the basal layer of squamous epithelia and absent from the healthy intestine and colon. We have previously shown it to be expressed in all inflamed, hyperplastic, and dysplastic intestinal and colonic mucosa. This study aimed to better understand the mechanisms controlling the expression of P-cadherin and the biological effects of its ectopic presence in the intestine and colon.

Increased colorectal epithelial cell proliferation and crypt fission associated with obesity and roux-en-Y gastric bypass.

Background And Aims: The relationship between obesity, weight reduction, and future risk of colorectal cancer is not well understood. Therefore, we compared mucosal biomarkers in normal weight individuals [body mass index (BMI), 18.5-24.

Dual inhibition of VEGFR and EGFR signaling reduces the incidence and size of intestinal adenomas in Apc(Min/+) mice.

Both the epidermal growth factor (EGF) and the vascular endothelial growth factor (VEGF) pathways are associated with intestinal cancer, and therapeutic approaches targeting either EGF receptor (EGFR) or VEGF receptor (VEGFR) signaling have recently been approved for patients with advanced colorectal cancer. The Apc(Min/+) mouse is a well-characterized in vivo model of intestinal tumorigenesis, and animals with this genetic mutation develop macroscopically detectable adenomas from approximately 6 weeks of age. Previous work in the Apc(Min/+) mouse has shown that therapeutic approaches targeting either VEGFR or EGFR signaling affect predominantly the size or number of adenomas, respectively.

Resistant carbohydrates stimulate cell proliferation and crypt fission in wild-type mice and in the Apc(Min/+) mouse model of intestinal cancer, association with enhanced polyp development.

Fermentation of carbohydrates in the colon can stimulate cell proliferation and could thus be a cancer risk. The effects of resistant carbohydrates, i.e.

Human pancreatic secretory trypsin inhibitor stabilizes intestinal mucosa against noxious agents.

Pancreatic secretory trypsin inhibitor (PSTI) is a serine protease inhibitor, expressed in gut mucosa, whose function is unclear. We, therefore, examined the effects of PSTI on gut stability and repair. Transgenic mice overexpressing human PSTI within the jejunum (FABPi(-1178 to +28) hPSTI construct) showed no change in baseline morphology or morphometry but reduced indomethacin-induced injury in overexpressing hPSTI region by 42% (P < 0.

Intestinal mucosa remodeling by recombinant human epidermal growth factor(1-48) in neonates with severe necrotizing enterocolitis.

Background And Aims: Neonatal necrotizing enterocolitis (NEC) is a common and serious acquired gastrointestinal tract condition. This clinical study assessed the potential clinical efficacy and microscopic effects of recombinant human epidermal growth factor 1-48 (EGF(1-48)) in neonates with NEC.

Methods: This prospective, double-blind, randomized controlled study included 8 neonates with NEC.

Use of growth-hormone-releasing peptide-6 (GHRP-6) for the prevention of multiple organ failure.

Novel therapies for the treatment of MOF (multiple organ failure) are required. In the present study, we examined the effect of synthetic GHRP-6 (growth hormone-releasing peptide-6) on cell migration and proliferation using rat intestinal epithelial (IEC-6) and human colonic cancer (HT29) cells as in vitro models of injury. In addition, we examined its efficacy when given alone and in combination with the potent protective factor EGF (epidermal growth factor) in an in vivo model of MOF (using two hepatic vessel ischaemia/reperfusion protocols; 45 min of ischaemia and 45 min of reperfusion or 90 min of ischaemia and 120 min of reperfusion).

Trefoil factor 2 (TFF2) deficiency in murine digestive tract influences the immune system.

Background And Aims: The gastrointestinal trefoil factor family (TFF1, TFF2, TFF3) peptides are considered to play an important role in maintaining the integrity of the mucosa. The physiological role of TFF2 in the protection of the GI tract was investigated in TFF2 deficiency.

Methods: TFF2-/- mice were generated and differential expression of various genes was assessed by using a mouse expression microarray, quantitative real time PCR, Northern blots or immunohistochemistry.

Intestinal growth in parenterally-fed rats induced by the combined effects of glucagon-like peptide 2 and epidermal growth factor.

Background: Parenteral nutrition and the absence of luminal feeding result in impaired intestinal growth and differentiation of enterocytes. Glucagon-like peptide 2 (GLP-2) and epidermal growth factor (EGF) have each been shown to have trophic effects on the intestine, and thus have the potential to benefit patients fed parenterally, such as those with intestinal failure from short bowel syndrome. We report studies aimed to determine whether there may be synergistic effects of these 2 peptides.

Differences in the effects of age on intestinal proliferation, crypt fission and apoptosis on the small intestine and the colon of the rat.

The increase in gastrointestinal epithelial tissue mass and the development of the gut can occur through three main mechanisms, namely elevated cell production from the intestinal crypts, by raised crypt number, which occurs through the process of crypt fission or by altered apoptosis. The small bowel and the colon have various rates of these, which were studied in rats of various ages. Wistar rats were fed ad libitum, and were killed at 3, 4, 6, 9, 12, 18, 26 and 48 weeks of age.

Myh deficiency enhances intestinal tumorigenesis in multiple intestinal neoplasia (ApcMin/+) mice.

Monoallelic APC and biallelic MYH (homolog of Escherichia coli mutY) germ-line mutations are independently associated with a strong predisposition to colorectal adenomas and carcinoma in humans. Whereas mice heterozygous for mutant Apc develop intestinal tumors, mice homozygous for mutant Myh do not show increased tumor susceptibility. We analyzed the phenotype of Apc(Min/+)/Myh(-/-) mice and found that they developed significantly more adenomas in the small intestine than did Apc(Min/+)/Myh(+/+) or Apc(Min/+)/Myh(+/-) mice (median 231 versus 151 versus 152).

Increased expression of specific intestinal amino acid and peptide transporter mRNA in rats fed by TPN is reversed by GLP-2.

Intestinal function depends on the presence of luminal nutrients and is altered during starvation and refeeding. Amino acids are essential for enterocytes, but the luminal supply is compromised with changes in dietary intake. To test the hypothesis that during periods of restricted luminal nutrient availability mucosal cells undergo adaptations aimed toward preserving amino acid supply, the expression of amino acid and peptide transporter mRNAs was quantified in rats with no oral intake, whose nutritional status was maintained with total parenteral nutrition (TPN).

The effects of lectins on indomethacin-induced small intestinal ulceration.

Growth factors, such as epidermal growth factor and keratinocyte growth factor, have considerable therapeutic potential for repairing mucosal injury in the intestine when given systemically. Recently, several lectins have been shown to have trophic effects on the intestine when given orally. We examined the effects of phytohaemagglutinin (PHA) and concanavalin A (Con-A) on indomethacin-induced intestinal injury in rat.

Bottom-up histogenesis of colorectal adenomas: origin in the monocryptal adenoma and initial expansion by crypt fission.

The adenoma:carcinoma sequence is well established. Understanding the molecular pathology of the adenoma is therefore important. There is great controversy within the field.

Keratinocyte growth factor and epidermal growth factor can reverse the intestinal atrophy associated with elemental diets in mice.

Elemental diets are associated with intestinal atrophy and reduced intestinal integrity. Growth factors such as keratinocyte growth factor (KGF) and epidermal growth factor (EGF) have considerable potential for the therapeutic reversal of such atrophy and may have greater actions if given in combination. We examined the effects of recombinant human KGF (rHuKGF), EGF and their combination on tissue mass, cell proliferation and crypt fission throughout the intestine of mice fed elemental diets.