Full characterization of PDX, a neuroprotectin/protectin D1 isomer, which inhibits blood platelet aggregation

Abstract

Our study aimed to establish the complete structure of the main dihydroxy conjugated triene issued from the lipoxygenation (soybean enzyme) of docosahexaenoic acid, named PDX, an isomer of protectin/neuroprotectin D1 (PD1/NPD1) described by Bazan and Serhan. NMR approaches and other chemical characterization (e.g. GC-MS, HPLC and LC-MS/MS) indicated that PDX is 10(S),17(S)-dihydroxy-docosahexa-4Z,7Z,11E,13Z,15E,19Z-enoic acid. The use of (18)O(2) and mass spectrometry showed that PDX is a double lipoxygenation product. Its structure differs from PD1, with E,Z,E geometry (PDX) instead of E,E,Z (PD1) and S configuration at carbon 10 instead of R. PDX inhibits human blood platelet aggregation at sub-micromolar concentrations.

Dose-effect and metabolism of docosahexaenoic acid: Pathophysiological relevance in blood platelets

“…Based on these data, we have reconsidered the possibility of making a double lipoxygenation product of DHA able to inhibit platelet aggregation. To this end, DHA was incubated with soybean lipoxygenase, known to produce 17(S)-hydroperoxy-DHA, and a main dihydroxy derivative has been isolated and characterized as 10(S),17(S)-dihydroxy-docosa-4Z,7Z,11E,13Z,15E,19Z-hexaenoic acid by a series of physico-chemical methods, including high performance chromatography coupled with mass spectrometry and NMR (32). This product, named protectin DX (PDX) is an isomer of protectin D1 (PD1) or 10(R),17(S)-dihydroxy-docosa-4Z,7Z,11E,13E,15Z,19Z-hexaenoic acid.…”

Characterization and biological effects of di-hydroxylated compounds deriving from the lipoxygenation of ALA

“…Synthesized hydroperoxides were reduced by sodium borohydride (NaBH 4 ) as previously described ( 18 ) . After acidification, mono-and di-hydroxylated fatty acids were extracted on a C18 solid-phase cartridge as previously described ( 18 ).…”

“…Synthesized hydroperoxides were reduced by sodium borohydride (NaBH 4 ) as previously described ( 18 ) . After acidification, mono-and di-hydroxylated fatty acids were extracted on a C18 solid-phase cartridge as previously described ( 18 ). Commercial 9(S)-HOTE, 9(S)-HpOTE, and the homemade racemic 9(±)-HOTE chemically produced by oxygen treatment of ALA and isolated by reverse-phase high-performance liquid chromatography (RP-HPLC) were further treated by sLOX in order to generate 9,16-di-HOTEs with defi ned stereochemistry.…”

Rescue and repair during photoreceptor cell renewal mediated by docosahexaenoic acid-derived neuroprotectin D1

“…NPD1 inhibits retinal ganglion cell death ( 71 ), is renal protective ( 72 ), and regulates adiponectin ( 73 ). Of interest, the double dioxygenation product 10 S ,17 S -diHDHA isomer of NPD1/PD1 was recently shown to have actions on platelets, reducing platelet aggregation at 0.3 M, 1 M, and higher concentrations ( 74 ). In peritonitis, this isomer also showed biological activity but was less potent than NPD1/PD1 ( 54,74 ).…”

“…Of interest, the double dioxygenation product 10 S ,17 S -diHDHA isomer of NPD1/PD1 was recently shown to have actions on platelets, reducing platelet aggregation at 0.3 M, 1 M, and higher concentrations ( 74 ). In peritonitis, this isomer also showed biological activity but was less potent than NPD1/PD1 ( 54,74 ). It is noteworthy that NPD1/ PD1 and the resolvins also are produced by trout tissues, including trout brain, from endogenous DHA, suggesting that these structures are highly conserved from fi sh to humans ( 75 ).…”