Abstract
Purpose :
Lipid mediators play important roles in regulating inflammatory responsesand tissue homeostasis in the eye. Polyunsaturated fatty acid(PUFA)-derived lipid mediators such as lipoxin A4 and protectin D1, that are locally produced by 12/15-lipoxygenase (12/15-LOX), are reported to be protective against cornea epithelial cell damage. In this study, we aim to determine comprehensive lipid mediator profiles in the eyes by using liquid choromatography mass spectrometry (LC-MS/MS-based) mediator lipidomics platform. Also we aimed to identify major cell types that express 12/15-LOX and potentially produce protective lipid mediators in the eye.
Methods :
We conducted comprehensive analyses of PUFA metabolites in the eyes by using LC-MS/MS system that is capable of simultaneous measurement of more than 500 fatty acid metabolites with high sensitivity. Eye samples was extracted by solid phase extraction to clean-up samples by removing interferences. Then samples are separated by HPLC, and PUFA metabolites are detected and quantified by triple quadrupole MS/MS using Multiple Reaction Monitoring (MRM) method.
Results :
As reported previously, 12/15-LOX-derived metabolites were abundantly present in the eye. Also cyclooxygenase (COX)-derived products such as prostaglandins were clearly detected, and of interest, the levels of COX metabolites were significantly reduced in 12/15-LOX knockout mice as compared to the wild types.
Conclusions :
Prostaglandins are known to be important regulator of inflammation and intraocular pressure, and the results indicate that there might be a functional interaction between 12/15-LOX and COX pathways that may contribute to tissue homeostasis in the eye. Cell types that contribute to local production of these lipid mediators in the eye are under investigation.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.