Eicosanoid profile in cultured human pulmonary artery smooth muscle cells treated with IL-1β and TNFα

Abstract

Interleukin-1β (IL-1β) and tumor necrosis factor (TNFα) induce prostanoid biosynthesis in vascular smooth muscle cells by promoting cyclooxygenase (COX) expression, but little is known about the biosynthesis of lipoxygenase (LPO) metabolites. We investigated the effects of human recombinant IL-1β and TNFα on the production of arachidonic acid (AA) metabolites by high-performance liquid chromatography (HPLC). After being labelled with 3H-AA, cultured human pulmonary artery smooth muscle cells (HPASMC) were incubated with or without IL-1β − (200 U/ml) and TNFα (500 U/ml). The arachidonic acid metabolites released from HPASMC were then analysed by HPLC. In control HPASMC, 6-keto-PGF 1α and PGE 2 were the principal metabolites of the COX pathway, while 5-HETE, LTC 4 and D 4 were the main products of the LPO pathway. HPASMC treated with 200 U/ml of IL-1β and 500 U/ml of TNF α produced more COX metabolites such as 6-keto-PGF 1α, thromboxane B2, PGF 2α and PGE 2 than control cells. Significant increases in the production of LPO derivatives such as LTB 4, C 4, D 4, and 15-HETE were also found in IL-1β-treated HPASMC. Although the release of LPO products tended to increase in TNFα-treated cells, no significant change was noted. Many AA metabolites including LTB 4 are responsible for the inflammatory process in vivo. AA metabolites produced by pulmonary artery smooth muscle cells might play important roles in cytokinemediated acute lung injury and inflammation.