title: Wound healing activity and mechanisms of action of an antibacterial protein from the venom of the eastern diamondback rattlesnake (Crotalus adamanteus).
abstract: Basic phospholipase A2 was identified from the venom of the eastern diamondback rattlesnake. The Crotalus adamanteus toxin-II (CaTx-II) induced bactericidal effects (7.8 µg/ml) on Staphylococcus aureus, while on Burkholderia pseudomallei (KHW), and Enterobacter aerogenes were killed at 15.6 µg/ml. CaTx-II caused pore formation and membrane damaging effects on the bacterial cell wall. CaTx-II was not cytotoxic on lung (MRC-5), skin fibroblast (HEPK) cells and in mice. CaTx-II-treated mice showed significant wound closure and complete healing by 16 days as compared to untreated controls (**P<0.01). Histological examination revealed enhanced collagen synthesis and neovascularization after treatment with CaTx-II versus 2% Fusidic Acid ointment (FAO) treated controls. Measurement of tissue cytokines revealed that interleukin-1 beta (IL-1β) expression in CaTx-II treated mice was significantly suppressed versus untreated controls. In contrast, cytokines involved in wound healing and cell migration i.e., monocyte chemotactic protein-1 (MCP-1), fibroblast growth factor-basic (FGF-b), chemokine (KC), granulocyte-macrophage colony-stimulating factor (GM-CSF) were significantly enhanced in CaTx-II treated mice, but not in the controls. CaTx-II also modulated nuclear factor-kappa B (NF-κB) activation during skin wound healing. The CaTx-II protein highlights distinct snake proteins as a potential source of novel antimicrobial agents with significant therapeutic application for bacterial skin infections.
authors.affiliation: Venom and Toxin Research Programme, Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore ; Infectious Diseases Programme, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Ramar Perumal
authors.initials: RP
authors.lastname: Samy
authors.affiliation: Infection & Immunity Programme, Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Brenner Centre for Molecular Medicine, Singapore, Singapore.
authors.forename: Matheswaran
authors.initials: M
authors.lastname: Kandasamy
authors.affiliation: Venom and Toxin Research Programme, Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Ponnampalam
authors.initials: P
authors.lastname: Gopalakrishnakone
authors.affiliation: Integrated Toxicology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, United States of America.
authors.forename: Bradley G
authors.initials: BG
authors.lastname: Stiles
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Edward G
authors.initials: EG
authors.lastname: Rowan
authors.affiliation: Department of Anatomy and Developmental Biology, University College London, London, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Becker
authors.affiliation: Department of Pharmacology, Clinical Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Muthu K
authors.initials: MK
authors.lastname: Shanmugam
authors.affiliation: Department of Pharmacology, Clinical Research Centre, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Gautam
authors.initials: G
authors.lastname: Sethi
authors.affiliation: Infectious Diseases Programme, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Vincent T K
authors.initials: VT
authors.lastname: Chow
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D015169:Colony Count, Microbial; D003435:Crotalid Venoms / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D017839:Crotalus / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D051379:Mice; D008826:Microbial Sensitivity Tests; D016328:NF-kappa B / Q000378:metabolism; D020539:Sequence Analysis, Protein; D012867:Skin / Q000187:drug effects / Q000473:pathology; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D003435:Crotalid Venoms; D016207:Cytokines; D018836:Inflammation Mediators; D016328:NF-kappa B; D003094:Collagen; D007770:L-Lactate Dehydrogenase