Limits...
Interlaboratory evaluation of rodent pulmonary responses to engineered nanomaterials: the NIEHS Nano GO Consortium.

Bonner JC, Silva RM, Taylor AJ, Brown JM, Hilderbrand SC, Castranova V, Porter D, Elder A, Oberdörster G, Harkema JR, Bramble LA, Kavanagh TJ, Botta D, Nel A, Pinkerton KE - Environ. Health Perspect. (2013)

Bottom Line: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health.TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs.Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, North Carolina, USA.

ABSTRACT

Background: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health. Interlaboratory studies in rodents using standardized protocols are needed to assess ENM toxicity.

Methods: Four laboratories evaluated lung responses in C57BL/6 mice to ENMs delivered by oropharyngeal aspiration (OPA), and three labs evaluated Sprague-Dawley (SD) or Fisher 344 (F344) rats following intratracheal instillation (IT). ENMs tested included three forms of titanium dioxide (TiO2) [anatase/rutile spheres (TiO2-P25), anatase spheres (TiO2-A), and anatase nanobelts (TiO2-NBs)] and three forms of multiwalled carbon nanotubes (MWCNTs) [original (O), purified (P), and carboxylic acid "functionalized" (F)]. One day after treatment, bronchoalveolar lavage fluid was collected to determine differential cell counts, lactate dehydrogenase (LDH), and protein. Lungs were fixed for histopathology. Responses were also examined at 7 days (TiO2 forms) and 21 days (MWCNTs) after treatment.

Results: TiO2-A, TiO2-P25, and TiO2-NB caused significant neutrophilia in mice at 1 day in three of four labs. TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs. Inflammation induced by TiO2 in mice and rats resolved by day 7. All MWCNT types caused neutrophilia at 1 day in three of four mouse labs and in all rat labs. Three of four labs observed similar histopathology to O-MWCNTs and TiO2-NBs in mice.

Conclusions: ENMs produced similar patterns of neutrophilia and pathology in rats and mice. Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons.

Show MeSH

Related in: MedlinePlus

Results of lung histopathology (A), BAL cytospins (B), and immunohistochemistry (C) for mice exposed to DM only (control) or O-MWCNTs (40 μg/50 μL). Abbreviations: a, alveolus; AD, alveolar ducts; BV, blood vessel; TB, terminal bronchioles. (A) Histopathology showing lung inflammatory response to O-MWCNTs. Centriacinar bronchiolitis/alveolitis (dashed arrows) was induced by O-MWCNTs in three of four labs (ML1, ML2, ML3); one lab (ML4) found some deposition of O-MWCNTs in alveolar ducts with marginal inflammation. Solid arrows indicate macrophages containing O-MWCNT. (B) BAL cytospin images of cells from the lungs of mice exposed to DM (control) or O-MWCNTs; > 95% of macrophages from O-MWCNT–exposed animals were enlarged, activated alveolar macro­phages with numerous MWCNT inclusions (solid arrows) and neutrophils that do not contain MWCNTs (dashed arrows). The images are from a single lab (ML3) but are typical of responses from ML1 and ML2. (C) Immunohistochemistry using a monoclonal rat anti-mouse neutrophil (allotypic marker clone 7/4) antibody showing the location of neutro­phils (dashed arrows) near terminal bronchioles and in relation to macrophages containing O-MWCNT (solid arrows). Representative images are from ML3.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3672912&req=5

f4: Results of lung histopathology (A), BAL cytospins (B), and immunohistochemistry (C) for mice exposed to DM only (control) or O-MWCNTs (40 μg/50 μL). Abbreviations: a, alveolus; AD, alveolar ducts; BV, blood vessel; TB, terminal bronchioles. (A) Histopathology showing lung inflammatory response to O-MWCNTs. Centriacinar bronchiolitis/alveolitis (dashed arrows) was induced by O-MWCNTs in three of four labs (ML1, ML2, ML3); one lab (ML4) found some deposition of O-MWCNTs in alveolar ducts with marginal inflammation. Solid arrows indicate macrophages containing O-MWCNT. (B) BAL cytospin images of cells from the lungs of mice exposed to DM (control) or O-MWCNTs; > 95% of macrophages from O-MWCNT–exposed animals were enlarged, activated alveolar macro­phages with numerous MWCNT inclusions (solid arrows) and neutrophils that do not contain MWCNTs (dashed arrows). The images are from a single lab (ML3) but are typical of responses from ML1 and ML2. (C) Immunohistochemistry using a monoclonal rat anti-mouse neutrophil (allotypic marker clone 7/4) antibody showing the location of neutro­phils (dashed arrows) near terminal bronchioles and in relation to macrophages containing O-MWCNT (solid arrows). Representative images are from ML3.

Mentions: Histopathological analysis was used to determine the site of deposition of MWCNTs and the type of inflammatory lesions caused by oropharyngeal exposure to MWCNTs. Figure 4A shows that O-MWCNTs delivered by OPA caused centriacinar bronchiolitis/alveolitis in mice in three of four labs (ML1, ML2, and ML3). One lab (ML4) observed O-MWCNTs primarily within alveolar ducts with little inflammation. In ML4, far fewer O-MWCNTs appeared to be delivered to the lungs (Figure 4A), which correlated with much lower percentages of neutrophils recovered from the mice in that lab (Figure 3A). The inflammatory response associated with MWCNT exposure was characterized by neutrophilia as determined by BALF cell differentials (Figure 4B) and by using immunohistochemical staining with an anti-neutrophil antibody, which revealed neutrophils near terminal bronchioles and in proximity to macrophages containing O-MWCNTs (Figure 4C).


Interlaboratory evaluation of rodent pulmonary responses to engineered nanomaterials: the NIEHS Nano GO Consortium.

Bonner JC, Silva RM, Taylor AJ, Brown JM, Hilderbrand SC, Castranova V, Porter D, Elder A, Oberdörster G, Harkema JR, Bramble LA, Kavanagh TJ, Botta D, Nel A, Pinkerton KE - Environ. Health Perspect. (2013)

Results of lung histopathology (A), BAL cytospins (B), and immunohistochemistry (C) for mice exposed to DM only (control) or O-MWCNTs (40 μg/50 μL). Abbreviations: a, alveolus; AD, alveolar ducts; BV, blood vessel; TB, terminal bronchioles. (A) Histopathology showing lung inflammatory response to O-MWCNTs. Centriacinar bronchiolitis/alveolitis (dashed arrows) was induced by O-MWCNTs in three of four labs (ML1, ML2, ML3); one lab (ML4) found some deposition of O-MWCNTs in alveolar ducts with marginal inflammation. Solid arrows indicate macrophages containing O-MWCNT. (B) BAL cytospin images of cells from the lungs of mice exposed to DM (control) or O-MWCNTs; > 95% of macrophages from O-MWCNT–exposed animals were enlarged, activated alveolar macro­phages with numerous MWCNT inclusions (solid arrows) and neutrophils that do not contain MWCNTs (dashed arrows). The images are from a single lab (ML3) but are typical of responses from ML1 and ML2. (C) Immunohistochemistry using a monoclonal rat anti-mouse neutrophil (allotypic marker clone 7/4) antibody showing the location of neutro­phils (dashed arrows) near terminal bronchioles and in relation to macrophages containing O-MWCNT (solid arrows). Representative images are from ML3.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672912&req=5

f4: Results of lung histopathology (A), BAL cytospins (B), and immunohistochemistry (C) for mice exposed to DM only (control) or O-MWCNTs (40 μg/50 μL). Abbreviations: a, alveolus; AD, alveolar ducts; BV, blood vessel; TB, terminal bronchioles. (A) Histopathology showing lung inflammatory response to O-MWCNTs. Centriacinar bronchiolitis/alveolitis (dashed arrows) was induced by O-MWCNTs in three of four labs (ML1, ML2, ML3); one lab (ML4) found some deposition of O-MWCNTs in alveolar ducts with marginal inflammation. Solid arrows indicate macrophages containing O-MWCNT. (B) BAL cytospin images of cells from the lungs of mice exposed to DM (control) or O-MWCNTs; > 95% of macrophages from O-MWCNT–exposed animals were enlarged, activated alveolar macro­phages with numerous MWCNT inclusions (solid arrows) and neutrophils that do not contain MWCNTs (dashed arrows). The images are from a single lab (ML3) but are typical of responses from ML1 and ML2. (C) Immunohistochemistry using a monoclonal rat anti-mouse neutrophil (allotypic marker clone 7/4) antibody showing the location of neutro­phils (dashed arrows) near terminal bronchioles and in relation to macrophages containing O-MWCNT (solid arrows). Representative images are from ML3.
Mentions: Histopathological analysis was used to determine the site of deposition of MWCNTs and the type of inflammatory lesions caused by oropharyngeal exposure to MWCNTs. Figure 4A shows that O-MWCNTs delivered by OPA caused centriacinar bronchiolitis/alveolitis in mice in three of four labs (ML1, ML2, and ML3). One lab (ML4) observed O-MWCNTs primarily within alveolar ducts with little inflammation. In ML4, far fewer O-MWCNTs appeared to be delivered to the lungs (Figure 4A), which correlated with much lower percentages of neutrophils recovered from the mice in that lab (Figure 3A). The inflammatory response associated with MWCNT exposure was characterized by neutrophilia as determined by BALF cell differentials (Figure 4B) and by using immunohistochemical staining with an anti-neutrophil antibody, which revealed neutrophils near terminal bronchioles and in proximity to macrophages containing O-MWCNTs (Figure 4C).

Bottom Line: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health.TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs.Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, North Carolina, USA.

ABSTRACT

Background: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health. Interlaboratory studies in rodents using standardized protocols are needed to assess ENM toxicity.

Methods: Four laboratories evaluated lung responses in C57BL/6 mice to ENMs delivered by oropharyngeal aspiration (OPA), and three labs evaluated Sprague-Dawley (SD) or Fisher 344 (F344) rats following intratracheal instillation (IT). ENMs tested included three forms of titanium dioxide (TiO2) [anatase/rutile spheres (TiO2-P25), anatase spheres (TiO2-A), and anatase nanobelts (TiO2-NBs)] and three forms of multiwalled carbon nanotubes (MWCNTs) [original (O), purified (P), and carboxylic acid "functionalized" (F)]. One day after treatment, bronchoalveolar lavage fluid was collected to determine differential cell counts, lactate dehydrogenase (LDH), and protein. Lungs were fixed for histopathology. Responses were also examined at 7 days (TiO2 forms) and 21 days (MWCNTs) after treatment.

Results: TiO2-A, TiO2-P25, and TiO2-NB caused significant neutrophilia in mice at 1 day in three of four labs. TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs. Inflammation induced by TiO2 in mice and rats resolved by day 7. All MWCNT types caused neutrophilia at 1 day in three of four mouse labs and in all rat labs. Three of four labs observed similar histopathology to O-MWCNTs and TiO2-NBs in mice.

Conclusions: ENMs produced similar patterns of neutrophilia and pathology in rats and mice. Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons.

Show MeSH
Related in: MedlinePlus