Poster Topical Area: Energy and Macronutrient Metabolism

Location: Hall D

Poster Board Number: 494

P10-095 - Detection of plasmalogen hydroperoxide in human plasma

Monday, Jun 11
8:00 AM – 3:00 PM

Objectives

Plasmalogen (Pls) is a physiologically important class of vinyl ether-linked phospholipid. Recently, patients suffering from neurodegenerative disorders have been reported to exhibit reduced levels of choline Pls (PC-Pls) and ethanolamine Pls (PE-Pls) in blood plasma. One of the potential cause of this reduction is oxidation, since Pls is vulnerable to oxidation due to the presence of vinyl ether bound. So far Pls oxidation has been mainly discussed about cleavage of vinyl ether bound (i.e. yielding lyso phospholipid), despite the fact that poly-unsaturated fatty acid (PUFA) moiety of Pls is known to be highly susceptible to oxidation, due to the luck of the suitable analytical method. Therefore, in this study, we aimed to construct the novel method for detection of Pls bearing oxidized PUFA and reveal whether PUFA moiety of Pls is oxidized.


Methods


The standard of PC-Pls (16:0/18:2) was oxidized by 15-lipoxygenase. The resultant PC-Pls bearing 13-hydroperoxy-octadecadienoyl at sn-2 (PC-Pls 16:0/13-HpODE) was analyzed by mass spectrometry (MS/MS) in the presence of the sodium ion. Hydroperoxide-specific product ion was used for the high performance liquid chromatography (LC)-MS/MS operated in multiple reaction monitoring mode. Then plasma phospholipid fraction was analyzed.


Results and Discussion


In the presence of sodium ion, characteristic product ion from PC-Pls 16:0/13-HpODE was determined. Under the optimal LC-MS/MS condition, PC-Pls 16:0/13-HpODE was found to be detected in human plasma. It became clear that PUFA moiety of Pls was also target to be oxidized. Now we are applying the novel method to analyze clinical samples.



Conclusion

The method described here would provide a better understanding physiological roles of Pls in vivo.




Funding Source:

Application Procedures for Grants-in-Aid for Scientific Research - KAKENHI -

CoAuthors: Shunji Kato – Tokai University School of Medicine; Teruo Miyazawa – Tohoku University; Kiyotaka Nakagawa – Tohoku University

Yurika Otoki

Postdoctoral fellow
Tohoku University
Davis, California