Quantitative Profiling of Oxylipins in Acute Experimental Intracerebral Hemorrhage

Oxylipins are a series of bioactive lipid metabolites derived from polyunsaturated fatty acids that are involved in cerebral homeostasis and the development of intracerebral hemorrhage (ICH). However, comprehensive quantification of the oxylipin profile in ICH remains unknown. Therefore, an ICH mouse model was constructed and liquid chromatography tandem mass spectrometry was then performed to quantify the change in oxylipins in ICH. The expression of the oxylipin relative enzymes was also reanalyzed based on RNA-seq data from our constructed ICH dataset. A total of 58 oxylipins were quantifiable and the levels of 17 oxylipins increased while none decreased significantly in the first 3 days following ICH. The most commonly increased oxylipins in ICH were derived from AA (10/17) and EPA (4/17) followed by LA (2/17) and DHA (1/17). 18-HEPE from EPA was the only oxylipin that remained significantly increased from 0.5 to 3 days following ICH. Furthermore, 14 of the increased oxylipins reached a peak level on the first day of ICH, and soon decreased while five oxylipins (PGJ2, 15-oxo-ETE, 12-HEPE, 18-HEPE, and 5-oxo-ETE) had increased 3 days after ICH suggesting that the profile shifted with the progression of ICH. In our constructed RNA-seq dataset based on ICH rats, 90 oxylipin relative molecules were detected except for COX. Among these, Cyp4f18, Cyp1b1, Cyp2d3, Cyp2e1, Cyp1a1, ALOX5AP, and PLA2g4a were found up-regulated and Cyp26b1 was found to decrease in ICH. In addition, there was no significant change in sEH in ICH. This study provides fundamental data on the profile of oxylipins and their enzymes in ICH. We found that the profile shifted as the progression of ICH and the metabolism of arachidonic acid and eicosapentaenoic acid was highly affected in ICH, which will help further studies explore the functions of oxylipins in ICH.