Purpose: Bacterial overgrowth commonly occurs and favors bacterial translocation in short bowel syndrome (SBS). Glucagon-like peptide-2 (GLP-2) is effective for treating SBS, but is rapidly inactivated by dipeptidyl peptidase IV (DPP4). DPP4 inhibitor (DPP4I) is known to be effective for treating SBS. Here, we investigated cell junction protein function following DPP4I administration in a mouse model of SBS.
Methods: Mice were divided into four groups: naïve (n = 5), naïve + DPP4I (n = 6), control (n = 6), and DPP4I (n = 5). All control and DPP4I mice had 50% of their proximal small bowel resected. DPP4I or normal saline was administered orally twice daily from days 1-7 postoperatively. The functions of cell junction proteins were assessed by RT-PCR and immunohistochemistry. Body weights and blood glucose levels were recorded.
Results: E-Cadherin was significantly higher in the DPP4I group than in the control group. E-Cadherin, occludin, and claudin-4 were significantly higher in the naïve group than in the control group. Positive staining for E-cadherin and occludin varied widely between the control and DPP4I groups.
Conclusion: Up-regulation of E-cadherin and occludin by DPP4I may be correlated with the anti-inflammatory action of DPP4I. Therefore, DPP4I may reduce bacterial translocation in SBS.
Keywords: DPP4 inhibitor; E-Cadherin; Occludin; Short bowel syndrome; Tight junction protein.