Respirable Quartz and Kaolin Alumino-Silicate Induction of In Vitro Cytotoxicity and Apoptosis in the Presence of Surfactant or Serum: Caveats to Bioassay Interpretation

Details

• Personal Author:
  Gao N ; Keane MJ ; Martin, Jennifer E. ; Miller, William E. ; Ong T ; Wallace WE ; Ye J
• Description:
  Respirable sized quartz and kaolin dusts at concentrations from 0.25 to 1.0 mg/ml were comparably cytotoxic measured as lactate dehydrogenase (LDR) release from lavaged rat lung macrophages challenged for 2 b in serum-free medium. Kaolin was about twice as active as quartz on a mass basis and about half as active on a surface area basis. Use of fetal bovine serum (FRS) in the medium reduced this activity for both dusts in a serum concentration-dependent manner. Using rat alveolar macrophage-derived NR8383 cells in medium containing 10% FBS, quartz dust challenge for 6 h at dust concentrations from 50 to 400 J.1g/ml induced significant and dust concentration-dependent necrosis, as measured by LDR release, and apoptosis, as measured by the terminal deoxynucleotidyl transferase-mediated dUTP-fluorescein nick end DNA labeling assay. Under these same conditions, kaolin dust was significantly active only at the highest dust concentration. Challenge at an intermediate concentration of 100 J.1g/mi over time periods of 6 h to 5 days produced significant LDR release with quartz at all times, while kaolin-induced activity was significant only at 3 and 5 days and was not as strong as quartz- induced activity at those times. Pretreatment of quartz with dipalmitoyl phosphatidylcholine (DPPC), to model conditioning of respired dust surfaces by interaction with a primary pbospholipid component of the pulmonary surfactant, further suppressed quartz activity in the FBS system over 3 days, with no additional DPPC prophylactic effect seen at 5 days. No additional prophylactic effect of DPPC was seen for kaolin in the FBS system. In vitro assays of respirable particulate necrotic or apoptotic activities can be significantly affected by non-physiologically meaningful surface modifications of dusts occurring in a cellular test system, as observed here for serum in cell culture medium. At the same time, interpretation of in vitro assays may be limited if in vivo physiological modification of particle surfaces, such as adsorption of prophylactic components of lung surfactant as studied here, is not modeled in the experimental design. [Description provided by NIOSH]
• Subjects:
  Biological Assay Cytotoxins Dust Lung Occupational Health Quartz Respiratory System Safety Silicon Dioxide Surface-Active Agents
• Keywords:
  Apoptosis Author Keywords: Quartz Bioassays Cytotoxicity DPPC Surfactant Fetal Bovine Serum In-vitro-studies Kaolin Lactate Dehydrogenase NR 8383 Cells Quartz-dust Surfactants TUNEL

  More +
• ISSN:
  0003-4878
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  50-52
• Volume:
  46
• NIOSHTIC Number:
  nn:20022267
• Citation:
  Ann Occup Hyg, Inhaled Particles IX, 2002 Dec; 46(Suppl 1):50-52
• Contact Point Address:
  W. E. Wallace, National Institute for Occupational Safety and Health, 1095 Willowdale Road, Morgantown, WV 26505, USA
• Editor(s):
  Ogden T; Donaldson K; Cherry N
• Federal Fiscal Year:
  2003
• Peer Reviewed:
  True
• Source Full Name:
  Annals of Occupational Hygiene, Inhaled Particles IX
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:256afcac69fd4a69642a85ad248055dcfc83f6f9797ffa46048f1056a3a9fc641f43ccc5ec2d90869279e47a5ed6a5bb71dc8f786fc1992d187ae2af04f012be
• Download URL:
  https://stacks.cdc.gov/view/cdc/199099/cdc_199099_DS1.pdf
• File Type:
  [PDF - 65.26 KB ]