title: Nitrogen mustard exposure of murine skin induces DNA damage, oxidative stress and activation of MAPK/Akt-AP1 pathway leading to induction of inflammatory and proteolytic mediators.
abstract: Our recent studies in SKH-1 hairless mice have demonstrated that topical exposure to nitrogen mustard (NM), an analog of sulfur mustard (SM), triggers the inflammatory response, microvesication and apoptotic cell death. Here, we sought to identify the mechanism/s involved in these NM-induced injury responses. Results obtained show that NM exposure of SKH-1 hairless mouse skin caused H2A.X and p53 phosphorylation and increased p53 accumulation, indicating DNA damage. In addition, NM also induced the activation of MAPKs/ERK1/2, JNK1/2 and p38 as well as that of Akt together with the activation of transcription factor AP1. Also, NM exposure induced robust expression of pro-inflammatory mediators namely cyclooxygenase 2 and inducible nitric oxide synthase and cytokine tumor necrosis factor alpha, and increased the levels of proteolytic mediator matrix metalloproteinase 9. NM exposure of skin also increased lipid peroxidation, 5,5-dimethyl-2-(8-octanoic acid)-1-pyrroline N-oxide protein adduct formation, protein and DNA oxidation indicating an elevated oxidative stress. We also found NM-induced increase in the homologous recombinant repair pathway, suggesting its involvement in the repair of NM-induced DNA damage. Collectively, these results indicate that NM induces oxidative stress, mainly a bi-phasic response in DNA damage and activation of MAPK and Akt pathways, which activate transcription factor AP1 and induce the expression of inflammatory and proteolytic mediators, contributing to the skin injury response by NM. In conclusion, this study for the first time links NM-induced mechanistic changes with our earlier reported murine skin injury lesions with NM, which could be valuable to identify potential therapeutic targets and rescue agents.
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Dileep
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Neera
authors.initials: N
authors.lastname: Tewari-Singh
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Chapla
authors.initials: C
authors.lastname: Agarwal
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Anil K
authors.initials: AK
authors.lastname: Jain
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Swetha
authors.initials: S
authors.lastname: Inturi
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Rama
authors.initials: R
authors.lastname: Kant
authors.affiliation: Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA.
authors.forename: Carl W
authors.initials: CW
authors.lastname: White
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora 80045, CO, USA. Electronic address: Rajesh.Agarwal@UCDenver.edu.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Agarwal
mesh_terms: D000818:Animals; D002619:Chemical Warfare Agents / Q000633:toxicity; D004249:DNA Damage / Q000187:drug effects*; D015971:Gene Expression Regulation, Enzymologic; D006657:Histones / Q000235:genetics / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism; D015227:Lipid Peroxidation; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008297:Male; D008466:Mechlorethamine / Q000633:toxicity*; D051379:Mice; D008812:Mice, Hairless; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D012869:Skin Absorption; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: D002619:Chemical Warfare Agents; D006657:Histones; D008466:Mechlorethamine; D020929:Mitogen-Activated Protein Kinase Kinases; D010447:Peptide Hydrolases; D010455:Peptides; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D051135:Rad51 Recombinase; D016159:Tumor Suppressor Protein p53; C513345:AP1 peptide; C495154:Rad51 protein, mouse; C475961:gamma-H2AX protein, mouse
keywords: DNA damage; Inflammatory mediators; Mitogenic and survival signaling; Nitrogen mustard; Oxidative stress; Proteolytic mediator; Skin injury