[Protective effects of recombinant intestinal trefoil factor against intestinal injuries induced by endotoxin in young rats].

Abstract

OBJECTIVE:

This study aimed to investigate the protective effects of recombinant intestinal trefoil factor (rITF) against intestinal injuries and the possible mechanism by examining the changes of diamine oxidase (DAO) and TNF-alpha and the intestinal ultrastructural changes in lipopolysaccharide (LPS) induced intestinal injuries.

METHODS:

Ninety-six ten-day-old Wistar rats were randomly injected with either normal saline (1 mL/kg, Control group), LPS (1 mL/kg) or LPS (1 mL/kg) + rITF (0.1 mL) intraperioneally. At 2, 6, 24 and 72 hrs after administration plasma DAO activity was determined using absorption spectrometry; and the intestinal protein and mRNA expression of TNF-alpha were measured using immunohistochemistry and RT-PCR methods. The intestinal ultrastructural changes were observed by electron microscopy.

RESULTS:

The plasma DAO activity in the LPS group began to increase at 2 hrs, peaked at 6 hrs and remained at significantly higher levels until 72 hrs after administration compared with the Control group (P < 0.01). The plasma DAO activity in the LPS + rITF group decreased noticeably compared with the LPS group at all time points (P < 0.01 or 0.05). A significant difference in the plasma DAO activity was only observed at 6 hrs after administration between the LPS + rITF and the Control group. The expression of TNF-alpha protein in the LPS group significantly increased at each time point, peaking at 6 hrs after LPS administration, with the IODT of TNF-alpha of 37,247.64 +/- 3,387.59 vs 6,191.02 +/- 482.32 (P < 0.01) compared with the Control group. rITF treatment decreased the expression of TNF-alpha protein although it remained significantly higher than in the Control group (P < 0.01). The TNF-alpha mRNA was weakly expressed in the Control group but strikingly increased after LPS injection (P < 0.01). Compared with the LPS group, the TNF-alpha mRNA expression in the LPS + rITF group decreased at all time points (P < 0.01 or 0.05). Vacuole changes of mitochodrium, cell nucleus condense, break and depletion of part of microvilli, and widen and disrupted tight junction were observed in the LPS group. The ultrastructural changes of intestinal tissues were improved in the LPS + rITF group.

CONCLUSIONS:

rITF can decrease the plasma DAO activity and inhibit the expression of TNF-alpha, resulting in a protective effect against intestinal injuries induced by LPS in young rats.

• Authors: Jun Li, Ling-Fen Xu, Mei Sun, Qiang Li, Hong Gao, Wei-Guo Jiang
• Journal: Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics (Zhongguo Dang Dai Er Ke Za Zhi) Vol. 8 Issue 5 Pg. 425-8 (Oct 2006) ISSN: 1008-8830 [Print] China
• PMID: 17052407 (Publication Type: Journal Article)

Chemical References

• Lipopolysaccharides
• Peptides
• RNA, Messenger
• Recombinant Proteins
• Trefoil Factor-2
• Tumor Necrosis Factor-alpha
• Amine Oxidase (Copper-Containing)

Topics

• Amine Oxidase (Copper-Containing) (blood)
• Animals
• Intestinal Mucosa (metabolism)
• Intestines (drug effects, pathology)
• Lipopolysaccharides (toxicity)
• Peptides (pharmacology)
• RNA, Messenger (analysis)
• Rats
• Rats, Wistar
• Recombinant Proteins (pharmacology)
• Trefoil Factor-2
• Tumor Necrosis Factor-alpha (analysis, genetics)