title: Proteomics-Based Identification of Differentially Abundant Proteins from Human Keratinocytes Exposed to Arsenic Trioxide.
abstract: BACKGROUND
  Arsenic is a widely distributed environmental toxicant that can cause multi-tissue pathologies. Proteomic assays allow for the identification of biological processes modulated by arsenic in diverse tissue types.
  
  
  METHODS
  The altered abundance of proteins from HaCaT human keratinocyte cell line exposed to arsenic was quantified using a label-free LC-MS/MS mass spectrometry workflow. Selected proteomics results were validated using western blot and RT-PCR. A functional annotation analytics strategy that included visual analytical integration of heterogeneous data sets was developed to elucidate functional categories. The annotations integrated were mainly tissue localization, biological process and gene family.
  
  
  RESULTS
  The abundance of 173 proteins was altered in keratinocytes exposed to arsenic; in which 96 proteins had increased abundance while 77 proteins had decreased abundance. These proteins were also classified into 69 Gene Ontology biological process terms. The increased abundance of transferrin receptor protein (TFRC) was validated and also annotated to participate in response to hypoxia. A total of 33 proteins (11 increased abundance and 22 decreased abundance) were associated with 18 metabolic process terms. The Glutamate--cysteine ligase catalytic subunit (GCLC), the only protein annotated with the term sulfur amino acid metabolism process, had increased abundance while succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial precursor (SDHB), a tumor suppressor, had decreased abundance.
  
  
  CONCLUSIONS
  A list of 173 differentially abundant proteins in response to arsenic trioxide was grouped using three major functional annotations covering tissue localization, biological process and protein families. A possible explanation for hyperpigmentation pathologies observed in arsenic toxicity is that arsenic exposure leads to increased iron uptake in the normally hypoxic human skin. The proteins mapped to metabolic process terms and differentially abundant are candidates for evaluating metabolic pathways perturbed by arsenicals.
authors.affiliation: RCMI Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson Mississippi 39217, USA.
authors.forename: Udensi K
authors.initials: UK
authors.lastname: Udensi
authors.affiliation: Proteomics Facility, University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR 72205, USA.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Tackett
authors.affiliation: Proteomics Facility, University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR 72205, USA.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Byrum
authors.affiliation: Proteomics Facility, University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR 72205, USA.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Avaritt
authors.affiliation: Proteomics Facility, University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR 72205, USA.
authors.forename: Deepanwita
authors.initials: D
authors.lastname: Sengupta
authors.affiliation: Proteomics Facility, University of Arkansas for Medical Sciences, Department of Biochemistry and Molecular Biology, Little Rock, AR 72205, USA.
authors.forename: Linley W
authors.initials: LW
authors.lastname: Moreland
authors.affiliation: RCMI Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson Mississippi 39217, USA.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Tchounwou
authors.affiliation: RCMI Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson Mississippi 39217, USA ; Department of Biology, School of Science, Engineering and Mathematics, Bethune-Cookman University, Daytona Beach FL 32114, USA.
authors.forename: Raphael D
authors.initials: RD
authors.lastname: Isokpehi
keywords: Arsenic; HaCaT keratinocytes; Proteomics; Skin cancer; TFRC; Visual analytics