Activation of group IVC phospholipase A(2) by polycyclic aromatic hydrocarbons induces apoptosis of human coronary artery endothelial cells.
Exposure to environmental pollutants, such as polycyclic aromatic hydrocarbons (PAHs) found in coal tar mixtures and tobacco sources, is considered a significant risk factor for the development of heart disease in humans. The goal of this study was to determine the influence of PAHs present at a Superfund site on human coronary artery endothelial cell (HCAEC) phospholipase A(2) (PLA(2)) activity and apoptosis. Extremely high levels of 12 out of 15 EPA high-priority PAHs were present in both the streambed and floodplain sediments at a site where an urban creek and its adjacent floodplain were extensively contaminated by PAHs and other coal tar compounds. Nine of the 12 compounds and a coal tar mixture (SRM 1597A) activated group IVC PLA(2) in HCAECs, and activation of this enzyme was associated with histone fragmentation and poly (ADP) ribose polymerase (PARP) cleavage. Genetic silencing of group IVC PLA(2) inhibited both (3)H-fatty acid release and histone fragmentation by PAHs and SRM 1597A, indicating that individual PAHs and a coal tar mixture induce apoptosis of HCAECs via a mechanism that involves group IVC PLA(2). Western blot analysis of aortas isolated from feral mice (Peromyscus leucopus) inhabiting the Superfund site showed increased PARP and caspase-3 cleavage when compared to reference mice. These data suggest that PAHs induce apoptosis of HCAECs via activation of group IVC PLA(2).
Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996-4545, USA. ptithof@utk.edu
Patricia K
PK
Tithof
Sean M
SM
Richards
Mona A
MA
Elgayyar
Fu-Minn
FM
Menn
Vijay M
VM
Vulava
Larry
L
McKay
John
J
Sanseverino
Gary
G
Sayler
Dawn E
DE
Tucker
Christina C
CC
Leslie
Kim P
KP
Lu
Kenneth S
KS
Ramos
D000818:Animals; D000835:Animals, Wild; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000737:chemistry / Q000378:metabolism; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004781:Environmental Exposure; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D020868:Gene Silencing; D054513:Group IV Phospholipases A2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D010542:Peromyscus; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000302:isolation & purification / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D045483:Rivers; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000302:isolation & purification / Q000633:toxicity*; D013714:Tennessee
D006657:Histones; D007527:Isoenzymes; D010446:Peptide Fragments; D011084:Polycyclic Aromatic Hydrocarbons; D012333:RNA, Messenger; D012987:Soil; D012989:Soil Pollutants; D011065:Poly(ADP-ribose) Polymerases; D054513:Group IV Phospholipases A2; C505409:Casp3 protein, mouse; D053148:Caspase 3