Intestinal Epithelial Restitution After TcdB Challenge and Recovery From Clostridium difficile Infection in Mice With Alanyl-Glutamine Treatment

• Published in: The Journal of infectious diseases 2013-05, Vol.207 (10), p.1505-1515
• Main Authors: Rodrigues, Raphael S., Oliveira, Renato A. C., Li, Yuesheng, Zaja-Milatovic, Snjezana, Costa, Lourrany B., Neto, Manuel B. Braga, Kolling, Glynis L., Lima, Aldo A., Guerrant, Richard L., Warren, Cirle Alcantara
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Apoptosis - drug effects; BACTERIA; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; Bacteriology; Biological and medical sciences; Cell growth; Cell Line; Cell lines; Cell Proliferation - drug effects; Clostridium difficile; Clostridium difficile - drug effects; Clostridium difficile - growth & development; Clostridium Infections - drug therapy; Clostridium Infections - microbiology; Diarrhea; Dipeptides - pharmacology; Disease Models, Animal; Enterocytes - drug effects; Enterocytes - metabolism; Enterocytes - microbiology; Epithelial cells; Fundamental and applied biological sciences. Psychology; Infections; Infectious diseases; Intestinal Mucosa - drug effects; Intestinal Mucosa - microbiology; Major and Brief Reports; Male; Medical sciences; Mice; Mice, Inbred C57BL; Microbiology; Miscellaneous; Necrosis - drug therapy; Necrosis - pathology; Rats; Toxins; Vancomycin - pharmacology
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/jit041

Background. Clostridium difficile is an anaerobic bacterium that causes antibiotic-associated diarrhea. It produces toxin A and toxin B (TcdB), which cause injury to the gut epithelium. Glutamine is a fundamental fuel for enterocytes, maintaining intestinal mucosal health. Alanyl-glutamine (AQ) is a highly soluble dipeptide derivative of glutamine. We studied whether administration of AQ ameliorates the effects of TcdB in the intestinal cells and improves the outcome of C. difficile infection in mice. Methods. WST-1 proliferation and cell-wounding-migration assays were assessed in IEC-6 cells exposed to TcdB, with or without AQ. Apoptosis and necrosis were assessed using Annexin V and flow cytometry. C57BL/6 mice were infected with VPI 10463 and treated with either vancomycin, AQ, or vancomycin with AQ. Intestinal tissues were collected for histopathologic analysis, apoptosis staining, and determination of myeloperoxidase activity. Results. AQ increased proliferation in intestinal cells exposed to TcdB, improved migration at 24 and 48 hours, and reduced apoptosis in intestinal cells challenged with TcdB. Infected mice treated with vancomycin and AQ had better survival and histopathologic findings than mice treated with vancomycin alone. Conclusions. AQ may reduce intestinal mucosal injury in C. difficile—infected mice by partially reversing the effects of TcdB on enterocyte proliferation, migration, and apoptosis, thereby improving survival from C. difficile infection.