Characterization of scavengers of gamma-ketoaldehydes that do not inhibit prostaglandin biosynthesis.
Chem Res Toxicol
; 23(1): 240-50, 2010 Jan.
Article
em En
| MEDLINE
| ID: mdl-20041722
ABSTRACT
Expression of cyclooxygenase-2 (COX-2) is associated with the development of many pathologic conditions. The product of COX-2, prostaglandin H(2) (PGH(2)), can spontaneously rearrange to form reactive gamma-ketoaldehydes called levuglandins (LGs). This gamma-ketoaldehyde structure confers a high degree of reactivity on the LGs, which rapidly form covalent adducts with primary amines of protein residues. Formation of LG adducts of proteins has been demonstrated in pathologic conditions (e.g., increased levels in the hippocampus in Alzheimer's disease) and during physiologic function (platelet activation). On the basis of knowledge that lipid modification of proteins is known to cause their translocation and to alter their function, we hypothesize that modification of proteins by LG could have functional consequences. Testing this hypothesis requires an experimental approach that discriminates between the effects of protein modification by LG and the effects of cyclooxygenase-derived prostanoids acting through their G-protein coupled receptors. To achieve this goal, we have synthesized and evaluated a series of scavengers that react with LG with a potency more than 2 orders of magnitude greater than that with the epsilon-amine of lysine. A subset of these scavengers are shown to block the formation of LG adducts of proteins in cells without inhibiting the catalytic activity of the cyclooxygenases. Ten of these selective scavengers did not produce cytotoxicity. These results demonstrate that small molecules can scavenge LGs in cells without interfering with the formation of prostaglandins. They also provide a working hypothesis for the development of pharmacologic agents that could be used in experimental animals in vivo to assess the pathophysiological contribution of levuglandins in diseases associated with cyclooxygenase up-regulation.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Prostaglandinas H
/
Prostaglandinas
/
Aminas
Limite:
Humans
Idioma:
En
Revista:
Chem Res Toxicol
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos