Articulo 017 FASEB Journal.pdf
datasetposted on 14.04.2019 by Juan Antonio Gimenez-Bastida, Claus Schneider, Takahiro Shibata, Koji Uchida
Datasets usually provide raw data for analysis. This raw data often comes in spreadsheet form, but can be any collection of data, on which analysis can be performed.
The 2 hemiketal (HK) eicosanoids HKD2 and HKE2 are the major products of the biosynthetic crossover of the 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2) pathways. HKs result from the rearrangement of a di-endoperoxide intermediate formed in the COX-2-dependent oxygenation of 5S-hydroxyeicosatetraenoic acid (5S-HETE). We analyzed HK biosynthesis in human leukocytes stimulated ex vivo and defined the biosynthetic roles of 5-LOX and COX-2, using inhibitors and incubations with exogenous substrates. Activation of leukocytes with LPS followed by treatment with the calcium ionophore A23187 resulted in the formation of PGE2, 5-HETE, and LTB4 as the principal metabolites of COX-2 and 5-LOX, respectively. The formation of HKD2 and HKE2 was highest after 15 min LPS treatment, and at that time, levels were similar to PGE2, but less than 5-HETE and LTB4 The time course of HK formation paralleled that of 5-HETE and LTB4, implying the availability of the 5S-HETE substrate as a limiting factor in biosynthesis rather than expression levels of COX-2. Specific inhibitors of COX-2 and 5-LOX decreased formation of HKD2 and HKE2 Platelets did not form HKs from exogenous 5S-HETE, implying that COX-1 is not involved. HKs are early products during an inflammatory event and require cells that express 5-LOX and COX-2 for their biosynthesis.-Giménez-Bastida, J. A., Shibata, T., Uchida, K., Schneider, C. Roles of 5-lipoxygenase and cyclooxygenase-2 in the biosynthesis of hemiketals E2 and D2 by activated human leukocytes.