title: The insect peptide coprisin prevents Clostridium difficile-mediated acute inflammation and mucosal damage through selective antimicrobial activity.
abstract: Clostridium difficile-associated diarrhea and pseudomembranous colitis are typically treated with vancomycin or metronidazole, but recent increases in relapse incidence and the emergence of drug-resistant strains of C. difficile indicate the need for new antibiotics. We previously isolated coprisin, an antibacterial peptide from Copris tripartitus, a Korean dung beetle, and identified a nine-amino-acid peptide in the α-helical region of it (LLCIALRKK) that had antimicrobial activity (J.-S. Hwang et al., Int. J. Pept., 2009, doi:10.1155/2009/136284). Here, we examined whether treatment with a coprisin analogue (a disulfide dimer of the nine peptides) prevented inflammation and mucosal damage in a mouse model of acute gut inflammation established by administration of antibiotics followed by C. difficile infection. In this model, coprisin treatment significantly ameliorated body weight decreases, improved the survival rate, and decreased mucosal damage and proinflammatory cytokine production. In contrast, the coprisin analogue had no apparent antibiotic activity against commensal bacteria, including Lactobacillus and Bifidobacterium, which are known to inhibit the colonization of C. difficile. The exposure of C. difficile to the coprisin analogue caused a marked increase in nuclear propidium iodide (PI) staining, indicating membrane damage; the staining levels were similar to those seen with bacteria treated with a positive control for membrane disruption (EDTA). In contrast, coprisin analogue treatment did not trigger increases in the nuclear PI staining of Bifidobacterium thermophilum. This observation suggests that the antibiotic activity of the coprisin analogue may occur through specific membrane disruption of C. difficile. Thus, these results indicate that the coprisin analogue may prove useful as a therapeutic agent for C. difficile infection-associated inflammatory diarrhea and pseudomembranous colitis.
authors.affiliation: Department of Life Science, College of Natural Science, Daejin University, Pocheon, Gyeonggido, South Korea.
authors.forename: Jin Ku
authors.initials: JK
authors.lastname: Kang
authors.forename: Jae Sam
authors.initials: JS
authors.lastname: Hwang
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Nam
authors.forename: Keun Jae
authors.initials: KJ
authors.lastname: Ahn
authors.forename: Heon
authors.initials: H
authors.lastname: Seok
authors.forename: Sung-Kuk
authors.initials: SK
authors.lastname: Kim
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Yun
authors.forename: Charalabos
authors.initials: C
authors.lastname: Pothoulakis
authors.forename: John Thomas
authors.initials: JT
authors.lastname: Lamont
authors.forename: Ho
authors.initials: H
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D001644:Bifidobacterium / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000473:pathology; D016360:Clostridioides difficile / Q000187:drug effects* / Q000302:isolation & purification; D001517:Coleoptera / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D024881:Drug Resistance, Bacterial; D004761:Enterocolitis, Pseudomembranous / Q000188:drug therapy* / Q000382:microbiology; D019476:Insect Proteins / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D007778:Lactobacillus / Q000187:drug effects; D008297:Male; D051379:Mice; D008826:Microbial Sensitivity Tests; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D019476:Insect Proteins; D009842:Oligopeptides; C570442:coprisin peptide, Copris tripartitus