Inflammatory bowel disease (IBD) affects millions of people worldwide, manifesting as ulcerative colitis and Crohn’s disease. These diseases cause chronic inflammation within the digestive tract, leading to significant morbidity.
DSS-Induced Colitis Model
At Scantox, the dextran sodium sulfate (DSS) mouse colitis model is a cornerstone in colitis research. Its reliability and relevance to human IBD make it an essential bridge between laboratory research and clinical applications.
DSS is administered through drinking water. We can simulate acute colitis (seven days of exposure) and chronic colitis (alternating five days with and without DSS) to mimic short-term and long-term effects.
The key features of the DSS-induced model include:
- Epithelial barrier breakdown of the colon reflecting the initial damage seen in human colitis
- Symptoms mimicking human colitis, such as colon bleeding, diarrhea, and inflammation
- Colon shortening indicating severe inflammation and structural changes in advanced human colitis
The DSS model is a preferred choice among researchers, as it is supported by extensive data.
TNBS-Induced Colitis Model
Scantox can also provide the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis animal model. This chemically induced model is similar to the DSS model in fostering significant structural alterations within the colon, making it suitable for evaluating drugs targeting these changes.
Transgenic Mouse Model
For customized studies requiring an enhanced inflammatory response, IL-10 knockout mice can be used upon request. The model leads to spontaneous colitis due to an unregulated immune response, which is particularly valuable for studying drugs that aim to modulate immune system activity or restore immune balance.
Evaluating Drug Efficacy Through the Disease Activity Index
The disease activity index is crucial for evaluating the effectiveness of your drug under development.
We analyze several indicators:
- Presence of diarrhea and blood in the colon: Indicates gastrointestinal distress or internal damage
- Colon shortening: Often a sign of severe inflammation
- Pro-inflammatory markers and cytokines (ELISA): Key measures include myeloperoxidase (MPO), an enzyme highly expressed in the colon during inflammation. Elevated MPO levels indicate inflammation, while a decrease signals reduced inflammatory responses.
- Molecular biology markers (qPCR): To detect changes at the genetic level due to inflammation or drug effects
- Histopathology evaluations: To assess tissue damage and inflammatory cell infiltration
Frequently Asked Questions
The DSS model effectively simulates human colitis by mimicking disruptions in epithelial integrity and subsequent inflammation. However, it differs in the sequence of events: In humans, inflammation usually precedes structural changes in the colon, while in mice, structural changes occur first. Despite these variations, it proves effective for testing specific treatments, such as 5-aminosalicyclic acids (5-ASA) (link to publication), also used to treat human colitis.
More questions about the colitis models and their applications?