PepT1-knockout mice harbor a protective metabolome beneficial for intestinal wound healing
Junsik Sung1, Lixin Wang1,2, Dingpei Long1
1Institute for Biomedical Sciences, Digestive Diseases Research Group, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, Georgia.
Abstract:
Genetic knockout (KO) of peptide transporter-1 (PepT1) protein is known to provide resistance to acute colitis and colitis-associated cancer (CAC) in mouse models. However, it was unclear which molecule(s) or pathway(s) formed the basis for these protective effects. Recently, we demonstrated that the PepT1-/- microbiota is sufficient to protect against colitis and CAC. Given that PepT1 KO alters the gut microbiome and thereby changes the intestinal metabolites that are ultimately reflected in the feces, we investigated the fecal metabolites of our PepT1 KO mice. Using a liquid chromatography-mass spectrometry (LC-MS)-based untargeted-metabolomics technique, we found that the fecal metabolites were significantly different between the KO and normal wild-type (WT) mice. Among the altered fecal metabolites, tuberonic acid (TA) was sevenfold higher in KO mouse feces than in WT mouse feces. Accordingly, we studied whether the increased TA could direct an anti-inflammatory effect. Using in vitro models, we discovered that TA not only prevented lipopolysaccharide (LPS)-induced inflammation in macrophages but also improved the epithelial cell healing processes. Our results suggest that TA, and possibly other fecal metabolites, play a crucial role in the pathway(s) associated with the anticolitis effects of PepT1 KO.NEW & NOTEWORTHY Fecal metabolites were significantly different between the KO and normal wild-type (WT) mice. One fecal metabolite, tuberonic acid (TA), was sevenfold higher in KO mouse feces than in WT mouse feces. TA prevented lipopolysaccharide (LPS)-induced inflammation in macrophages and improved the epithelial cell healing process.
Insights
Genetic knockout of peptide transporter-1 (PepT1) alters gut microbiota, increasing fecal tuberonic acid (TA). This metabolite shows anti-inflammatory effects and improves gut healing, explaining PepT1 KO
Area of Science:
- Gastroenterology
- Immunology
- Metabolomics
Background:
- Genetic knockout of peptide transporter-1 (PepT1) confers resistance to colitis and colitis-associated cancer (CAC) in mice.
- The underlying mechanisms and specific protective molecules remain largely unknown.
- Recent studies suggest the PepT1 knockout (KO) microbiota is sufficient for protection.
Purpose of the Study:
- To investigate fecal metabolites in PepT1 KO mice to identify molecules responsible for protective effects.
- To determine if increased fecal metabolites, specifically tuberonic acid (TA), possess anti-inflammatory properties and promote gut healing.
Main Methods:
- Untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS) to analyze fecal metabolites.
- In vitro assays to assess the effects of tuberonic acid (TA) on lipopolysaccharide (LPS)-induced inflammation in macrophages.
- In vitro assessment of TA's impact on epithelial cell healing processes.
Main Results:
- Fecal metabolite profiles significantly differed between PepT1 KO and wild-type (WT) mice.
- Tuberonic acid (TA) levels were sevenfold higher in the feces of PepT1 KO mice compared to WT mice.
- TA demonstrated anti-inflammatory effects by preventing LPS-induced inflammation in macrophages and enhanced epithelial cell repair.
Conclusions:
- Altered fecal metabolites, particularly tuberonic acid (TA), play a significant role in the protective effects observed in PepT1 KO mice against colitis.
- TA exhibits therapeutic potential for inflammatory conditions by reducing inflammation and promoting tissue healing.
- These findings highlight the gut microbiome-metabolome axis as a critical factor in managing inflammatory bowel diseases.
