title: Bitumen products alter bax, bcl-2 and cytokeratin expression: an in vivo study of chronically exposed road pavers.
abstract: BACKGROUND
  The skin of road pavers is chronically exposed to bitumen fumes, a mixture of volatile compounds and particles, containing several carcinogenic and non-carcinogenic polycyclic aromatic hydrocarbons. Bitumen fumes can alter cutaneous barrier integrity in various ways and induce skin diseases. The present study was devised to investigate the expression of apoptosis proteins (bax and bcl-2) and the cytokeratin pattern in skin specimens from road paving workers exposed to bitumen fumes using immunohistochemical techniques.
  
  
  METHODS
  Skin forearm punch biopsies from 16 occupationally exposed workers and an unexposed control group were processed for immunohistochemistry using a broad-spectrum anti-cytokeratin antibody and monoclonal antibodies for bax and bcl-2 immunostaining. Urinary 1-hydroxypyrene (1-OHP) was also determined.
  
  
  RESULTS
  Morphological specimen evaluation showed epidermal thinning of exposed skin and flattened dermal papillae. In sections from exposed subjects, grade 3 bax overexpression and cytokeratin immunoreaction was detected in all layers, while bcl-2 expression was downregulated (grade 1) and confined to the basal layer. There was a significant difference in 1-OHP values between road pavers and the control group (p < 0.05).
  
  
  CONCLUSIONS
  Overexpression of the cytokeratin pattern and bax and underexpression of bcl-2 in chronically bitumen-exposed skin suggest that bitumen fumes induce activation of apoptosis as a defense mechanism.
authors: Department of Anatomy, Diagnostic Pathology, Forensic Medicine, Hygiene and Public Health, University of Catania, Via S. Sofia 87, 95123 Catania, Italy. carla.loreto@unict.it
authors: Carla
authors: C
authors: Loreto
authors: Veneranda
authors: V
authors: Rapisarda
authors: Maria Luisa
authors: ML
authors: Carnazza
authors: Giuseppe
authors: G
authors: Musumeci
authors: Velia
authors: V
authors: D'Agata
authors: Matteo
authors: M
authors: Valentino
authors: Giuseppe
authors: G
authors: Martinez
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D006801:Humans; D006838:Hydrocarbons / Q000009:adverse effects*; D007633:Keratins / Q000378:metabolism*; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011721:Pyrenes / Q000378:metabolism; D012867:Skin / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; C494826:BAX protein, human; D006838:Hydrocarbons; D019253:Proto-Oncogene Proteins c-bcl-2; D011721:Pyrenes; D051028:bcl-2-Associated X Protein; D007633:Keratins; C006647:asphalt; C033146:1-hydroxypyrene