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Trichloroethylene decreases heat shock protein 90 interactions with endothelial nitric oxide synthase: implications for endothelial cell proliferation. Toxicol Sci 2003 May;73(1):90-7 PMID: 12657742

Pubmed ID

12657742

Abstract

Trichloroetheylene (TRI) is an environmental pollutant that has been linked to congenital heart defects (CHD). Endothelial nitric oxide synthase (eNOS) generation of nitric oxide (NO) plays an important role in endothelial cell proliferation, which is considered essential for normal blood vessel growth and development. We hypothesized that TRI alters the balance of NO and superoxide anion (O2-) to impair endothelial cell proliferation. Proliferating endothelial cells were pretreated with TRI (5 microM) and then stimulated with the calcium ionophore, A23187 (5 microM), to determine changes in endothelial cell and eNOS function with respect to NO and O2- generation. Immunoblots of eNOS, phospho-eNOS at serine 1179 (S1179), and the levels of associated heat shock protein 90 (hsp90) were used to define the activation state of eNOS. The effects of TRI (0.05-100 microM) on vascular endothelial growth factor (VEGF, 0.58 nM) induced endothelial cell proliferation were determined from cell counts. TRI decreased A23187-stimulated nitrite + nitrate production from 1.99 +/- 0.90 to 0.89 +/- 0.51 pmol/mg protein (p < 0.05; n = 6). In controls, Lomega-nitroargininemethylester (L-NAME) increased A23187-stimulated O2- production from 0.130 +/- 0.089 to 0.214 +/- 0.071 nmol/min/mg protein (p < 0.05; n = 5). In TRI-treated cultures, however, L-NAME decreased A23187-stimulated O2- production from 0.399 +/- 0.121 to 0.199 +/- 0.055 nmol/min/mg protein (p < 0.05; n = 5). TRI decreased hsp90 associated with eNOS by 46.7% and inhibited VEGF-stimulated endothelial cell proliferation by 12 to 35%. These data show that TRI alters hsp90 interactions with eNOS and induces eNOS to shift from NO to O2- generation. Our findings provide new insight into how TRI alters endothelial and eNOS function to impair VEGF-stimulated endothelial proliferation. Such changes in endothelial function may play an important role in the development of congenital heart defects.

Author List

Ou J, Ou Z, McCarver DG, Hines RN, Oldham KT, Ackerman AW, Pritchard KA Jr

Authors

Keith T. Oldham MD Professor in the Surgery department at Medical College of Wisconsin
Kirkwood A. Pritchard PhD Professor in the Surgery department at Medical College of Wisconsin




Scopus

2-s2.0-0038324417   31 Citations

MESH terms used to index this publication - Major topics in bold

Animals
Blotting, Western
Calcimycin
Cattle
Cell Division
Cells, Cultured
Endothelial Cells
Enzyme Inhibitors
HSP90 Heat-Shock Proteins
Ionophores
NG-Nitroarginine Methyl Ester
Nitric Oxide
Nitric Oxide Synthase
Nitric Oxide Synthase Type III
Phosphorylation
Precipitin Tests
Superoxides
Trichloroethylene
Vascular Endothelial Growth Factor A
jenkins-FCD Prod-336 69ef4a6b262d135130251597d5d39873903802b5