Dataset Information

An Inducible, Large-Intestine-Specific Transgenic Mouse Model for Colitis and Colitis-Induced Colon Cancer Research.

ABSTRACT: Animal models are an important tool to understand intestinal biology. Our laboratory previously generated C57BL/6-Tg(Car1-cre)5Flt transgenic mice (CAC) with large-intestine-specific Cre recombinase (Cre) expression as a model to study colon health.To expand the utility of the CAC mouse model by determining the impact of chemically induced colitis on CAC transgene expression.CAC mice were crossed to Rosa reporter mice (Rosa26R (flox/flox) ) with a lox-STOP-lox signal controlling ?-galactosidase (?gal) expression and then further crossed with Apc(CKO/CKO) mice in some experiments to delete Apc alleles (Apc (?580) ). Initially, 8-week-old CAC(Tg/WT);Rosa26R (flox/WT) ;Apc (?580/WT) mice were treated with dextran sulfate sodium (DSS) in drinking water (5 days, 0, 0.65, 1.35, or 2.0 %). Colon tissue damage and ?gal labeling were analyzed 10 day after stopping DSS. Next, 8-week-old CAC(Tg/WT);Rosa26R(flox/flox) mice were treated with 0 or 1.35 % DSS, and colonic ?gal labeling was assessed at 30 day post-DSS treatment. Finally, 10-week-old CAC(Tg/WT);Apc (?580/WT) mice were treated with DSS (0 or 2 %) for 5 days and colonic tumors were analyzed at 20 weeks.CAC(Tg/WT);Rosa26R (flox/WT) ;Apc (?580/WT) mice had a DSS dose-dependent increase in colon epithelial damage that correlated with increased epithelial ?gal labeling at 10 days (r (2) = 0.9, ? = 0.75). The ?gal labeling in CAC(Tg/WT);Rosa26R(flox/flox) mice colon remained high at 30 days, especially in the crypts of the healed ulcer. DSS also increased colon tumor incidence and multiplicity in CAC(Tg/WT);Apc (?580/WT) mice.DSS-mediated epithelial damage induces a persistent, Cre-mediated recombination of floxed alleles in CAC mice. This enables the examination of gene function in colon epithelium during experimental colitis and colitis-induced colon cancer.

SUBMITTER: Wang F

PROVIDER: S-EPMC5476293 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

An Inducible, Large-Intestine-Specific Transgenic Mouse Model for Colitis and Colitis-Induced Colon Cancer Research.

Wang Fa F Johnson Robert L RL Snyder Paul W PW DeSmet Marsha L ML Fleet James C JC

Digestive diseases and sciences 20151202 4

<h4>Background</h4>Animal models are an important tool to understand intestinal biology. Our laboratory previously generated C57BL/6-Tg(Car1-cre)5Flt transgenic mice (CAC) with large-intestine-specific Cre recombinase (Cre) expression as a model to study colon health.<h4>Aim</h4>To expand the utility of the CAC mouse model by determining the impact of chemically induced colitis on CAC transgene expression.<h4>Methods</h4>CAC mice were crossed to Rosa reporter mice (Rosa26R (flox/flox) ) with a l ...[more]

PMID: 26631394

Similar Datasets

Project description:Krüppel-like factor 5 (KLF5) is a pro-proliferative transcriptional regulator primarily expressed in the intestinal crypt epithelial cells. Constitutive intestine-specific deletion of Klf5 is neonatal lethal suggesting a crucial role for KLF5 in intestinal development and homeostasis. We have previously shown Klf5 to play an active role regulating intestinal tumorigenesis. Here we examine the effect of inducible intestine-specific deletion of Klf5 in adult mice. Klf5 is lost from the intestine beginning at day 3 after the start of a 5-day treatment with the inducer tamoxifen. Although the mice have no significant weight loss or lethality, the colonic tissue shows signs of epithelial distress starting at day 3 following induction. Accompanying the morphological changes is a significant loss of proliferative crypt epithelial cells as revealed by BrdU or Ki67 staining at days 3 and 5 after start of tamoxifen. We also observed a loss of goblet cells from the colon and Paneth cells from the small intestine upon induced deletion of Klf5. In addition, loss of Klf5 from the colonic epithelium is accompanied by a regenerative response that coincides with an expansion in the zone of Sox9 expression along the crypt axis. At day 11, both proliferation and Sox9 expression return to baseline levels. Microarray and quantitative PCR analyses reveal an up-regulation of several regeneration-associated genes (Reg1A, Reg3G and Reg3B) and down-regulation of many Klf5 targets (Ki-67, cyclin B, Cdc2 and cyclin D1). Sox9 and Reg1A protein levels are also increased upon Klf5 loss. Lentiviral-mediated knockdown of KLF5 and exogenous expression of KLF5 in colorectal cancer cell lines confirm that Sox9 expression is negatively regulated by KLF5. Furthermore, ChIP assays reveal a direct association of KLF5 with both the Sox9 and Reg1A promoters. We have shown that disruption of epithelial homeostasis due to Klf5 loss from the adult colon is followed by a regenerative response led by Sox9 and the Reg family of proteins. Our study demonstrates that adult mouse colonic tissue undergoes acute physiological changes to accommodate the loss of Klf5 withstanding epithelial damage further signifying importance of Klf5 in colonic homeostasis.

Project description:In Simian virus 40 (SV40) transgenic BALB/c WAP-T mice tumor development and progression is driven by SV40 tumor antigens encoded by inducible transgenes. WAP-T mice constitute a well characterized mouse model for breast cancer with strong similarities to the corresponding human disease. BALB/c mice mount only a weak cellular immune response against SV40 T-antigen (T-Ag). For studying tumor antigen specific CD8+ T-cell responses against transgene expressing cells, we created WAP-TNP mice, in which the transgene additionally codes for the NP118-126-epitope contained within the nucleoprotein of lymphocytic choriomeningitis virus (LCMV), the immune-dominant T-cell epitope in BALB/c mice. We then investigated in WAP-TNP mice the immune responses against SV40 tumor antigens and the NP-epitope within the chimeric T-Ag/NP protein (T-AgNP). Analysis of the immune-reactivity against T-Ag in WAP-T and of T-AgNP in WAP-TNP mice revealed that, in contrast to wild type (wt) BALB/c mice, WAP-T and WAP-TNP mice were non-reactive against T-Ag. However, like wtBALB/c mice, WAP-T as well as WAP-TNP mice were highly reactive against the immune-dominant LCMV NP-epitope, thereby allowing the analysis of NP-epitope specific cellular immune responses in WAP-TNP mice. LCMV infection of WAP-TNP mice induced a strong, LCMV NP-epitope specific CD8+ T-cell response, which was able to specifically eliminate T-AgNP expressing mammary epithelial cells both prior to tumor formation (i.e. in cells of lactating mammary glands), as well as in invasive tumors. Elimination of tumor cells, however, was only transient, even after repeated LCMV infections. Further studies showed that already non-infected WAP-TNP tumor mice contained LCMV NP-epitope specific CD8+ T-cells, albeit with strongly reduced, though measurable activity. Functional impairment of these 'endogenous' NP-epitope specific T-cells seems to be caused by expression of the programmed death-1 protein (PD1), as anti-PD1 treatment of splenocytes from WAP-TNP tumor mice restored their activity. These characteristics are similar to those found in many tumor patients and render WAP-TNP mice a suitable model for analyzing parameters to overcome the blockade of immune checkpoints in tumor patients.

Dataset Information

An Inducible, Large-Intestine-Specific Transgenic Mouse Model for Colitis and Colitis-Induced Colon Cancer Research.

Publications

An Inducible, Large-Intestine-Specific Transgenic Mouse Model for Colitis and Colitis-Induced Colon Cancer Research.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets