Murine Colitis Modeling using Dextran Sulfate Sodium (DSS)

Summary

Dextran sulfate sodium (DSS) administered in the drinking water is an established murine inflammatory injury model of acute colitis. This protocol outlines the method for DSS treatment and the preparation of tissues.

Abstract

Colitis can occur from viral or bacterial infections, ischemic insult, or autoimmune disorders; most notably Ulcerative Colitis and the colonic variant of Crohn’s Disease - Crohn’s Colitis. Acute colitis may present with abdominal pain and distention, malabsorption, diarrhea, hematochezia and mucus in the stool. We are beginning to understand the complex interactions between the environment, genetics, and epithelial barrier dysfunction in Inflammatory Bowel Disease and animal models of colitis have been essential in advancing our understanding of this disease. One popular model involves supplementing the drinking water of mice with low-molecular weight Dextran Sodium Sulfate (DSS), resulting in epithelial damage and a robust inflammatory response in the colon lasting several days ¹.Variations of this approach can be used to model acute injury, acute injury followed by repair, and repeated cycles of DSS interspersed with recovery modeling chronic inflammatory diseases ². After a single four-day treatment of 3% DSS in drinking water, mice show signs of acute colitis including weight loss, bloody stools, and diarrhea. Mice are euthanized at the conclusion of the treatment course and at necropsy dissected colons are processed and can be 'Swiss rolled" ³ to allow microscopic analysis of the entire colon or infused with formalin as "sausages" to allow macroscopic analysis. Tissue is then embedded in paraffin, sectioned, and stained for histologic review.

Protocol

Part 1: Injury-Repair Colitis Model

1. Baseline weight should be obtained for each mouse prior to beginning DSS treatment.
2. Make a 3% (w/v) Dextran Sulfate Sodium Salt solution in water and filter with a 0.45 μm cellulose acetate filter.
3. Replace drinking water in the mouse cage with the 3% DSS solution for four days. The mice should not have access to any other source of water (i.e. exclusion tips placed on automated watering systems).
4. On day four, replace the DSS solution with water for an additional three days, allowing some colonic epithelial recovery. The mice should be weighed on day four in order to quantify systemic con....

Discussion

This protocol can be modified to model acute injury, injury-repair, or chronic colonic injury processes.

Acute Injury Modification:

DSS treatment ad lib for 4-6 days followed by immediate sacrifice

Injury-Repair Modification:

Injury with 4-6 days of DSS treatment followed by recovery period of 3-4 days and sacrifice (as described in above protocol).

Chronic Colitis Modification:

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Dextran Sulfate Sodium Salt	USB Corp., Affymetrix	9011-18-1	mol wt 40,000-50,000
10% Buffered Formalin Phosphate	Fisher Scientific	SF100-4
Isoflurane, USP	Phoenix Pharmaceuticals, Inc.	NDC 57319-474-06
TISSUE PATH Macrosette Cassettes	Fisher Scientific	15182706
BD 10 ml Syringe	BD Biosciences	309604
Ethyl Alcohol	Pharmco-AAPER	E190	Dilute to 70% with distilled water
20G Straight Feeding Needle	VWR international	20068-612
27G1/2 PrecisionGlide Needle	BD Biosciences	305109
Dissecting Scissors Sharp/Blunt Tip	VWR international	82027-588
Waugh Forceps	VWR international	82027-428
Non-absorbable Suture	LOOK Surgical	SP116
Whatman Blotting Paper	VWR international	28298-020	Cut as needed
Nalgene Surfactant-Free Cellulose Acetate (SFCA) Filter	Cole-Parmer	EW-06731-2
Carbon fiber composites digital caliper	Fisher Scientific	15-007-958