S-Arylcysteine–Keratin Adducts as Biomarkers of Human Dermal Exposure to Aromatic Hydrocarbons

Details

• Personal Author:
  Ball LM ; Fox DD ; French JE ; Gold, Avram ; Jayaraj K ; Kang-Sickel J-CC ; Klapper DG ; Nam T-g ; Nylander-French LA
• Description:
  To measure biomarkers of skin exposure to ubiquitous industrial and environmental aromatic hydrocarbons, we sought to develop an ELISA to quantitate protein adducts of metabolites of benzene and naphthalene in the skin of exposed individuals. We hypothesized that electrophilic arene oxides formed by CYP isoforms expressed in the human skin react with nucleophilic sites on keratin, the most abundant protein in the stratum corneum that is synthesized de novo during keratinocyte maturation and differentiation. The sulfhydryl groups of cysteines in the head region of the keratin proteins 1 (K1) and 10 (K10) are likely targets. The following synthetic S-arylcysteines were incorporated into 10-mer head sequences of K1 [GGGRFSS(S-aryl-C)GG] and K10 [GGGG(S-aryl-C)GGGGG] to form the predicted immunogenic epitopes for antibody production for ELISA: S-phenylcysteine-K1 (SPK1), S-phenylcysteine-K10 (SPK10), S-(1-naphthyl)cysteine-K1 (1NK1), S-(1-naphthyl)cysteine-K10 (1NK10), S-(2-naphthyl)cysteine-K1 (2NK1), and S-(2-naphthyl)cysteine-K10 (2NK10). Analysis by ELISA was chosen based on its high throughput and sensitivity, and low cost. The synthetic modified oligopeptides, available in quantity, served both as immunogens and as chemical standards for quantitative ELISA. Polyclonal rabbit antibodies produced against the naphthyl-modified keratins reacted with their respective antigens with threshold sensitivities of 15-31 ng/mL and high specificity over a linear range up to 500 ng/mL. Anti-S-phenylcysteine antibodies were not sufficiently specific or sensitive toward the target antigens for use in ELISA under our experimental conditions. In dermal tape-strip samples collected from 13 individuals exposed to naphthalene-containing jet fuel, naphthyl-conjugated peptides were detected at levels from 0.343 +/- 0.274 to 2.34 +/- 1.61 pmol adduct/ug keratin but were undetectable in unexposed volunteers. This is the first report of adducts of naphthalene (or of any polycyclic aromatic hydrocarbon) detected in the exposed intact human skin. Quantitation of naphthyl-keratin adducts in the skin of exposed individuals will allow us to investigate the importance of dermal penetration, metabolism, and adduction to keratin and to predict more accurately the contribution of dermal exposure to systemic dose for use in exposure and risk-assessment models. [Description provided by NIOSH]
• Subjects:
  Biomarkers Enzymes Hydrocarbons Occupational Health Safety Skin Skin Absorption
• Keywords:
  Aromatic Hydrocarbons Dermal Exposures Dose Response ELISA Enzyme-linked Immunosorbent Assay Exposure Assessment Risk Assessment Skin Absorption Skin Exposure
• ISSN:
  0893-228X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  North Carolina ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  21
• Issue:
  4
• NIOSHTIC Number:
  nn:20054135
• Citation:
  Chem Res Toxicol 2008 Apr; 21(4):852-858
• Contact Point Address:
  Leena A. Nylander-French, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill
• Email:
  leena_french@unc.edu
• CAS Registry Number:
  Benzene (CAS RN 71-43-2) ; Naphthalene (CAS RN 91-20-3)
• Federal Fiscal Year:
  2008
• Performing Organization:
  University of North Carolina, Chapel Hill
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Chemical Research in Toxicology
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:50001787479a1715f6fa665c3cdccbb14cce9ebf23c9e5dc8d1a6a21a22ce1f676d0af4e7ddb78b44337a02c85220b0f21635de21abe23760828d33641366b3f
• Download URL:
  https://stacks.cdc.gov/view/cdc/216765/cdc_216765_DS1.pdf
• File Type:
  [PDF - 1.28 MB ]