Phospholipid profiles of control and glaucomatous human aqueous humor

Abstract

To compare phospholipid (phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine and phosphatidylinositol) profiles of human control and glaucomatous aqueous humor (AQH). AQH samples were procured during surgery from human POAG and control subjects (n=15 each). Samples were used following institutional review board approved protocols and adhering to the tenets of the Declaration of Helsinki. Lipid extraction was performed using a modification of the Bligh and Dyer method, protein concentrations were determined using the Bradford’s method, and select samples were confirmed with Densitometry of PHAST gels. Lipids were identified and subjected to ratiometric quantification using a TSQ Quantum Access Max triple quadrupole mass spectrometer utilizing precursor ion scan (PIS) or neutral ion loss scan (NLS) using appropriate class specific lipid standards in a two step quantification process. The comparative profiles of phosphatidylcholines, phosphatidylserines, phosphatidylethanolamines and phosphatidylinositols between control and glaucomatous AQH showed several species common between them. A number of unique lipids in all four phospholipid classes were also identified in control eyes that were absent in glaucomatous eyes and vice versa. A number of phospholipids were found to be uniquely present in control, but absent in glaucomatous AQH and vice versa. Compared with a previous study of control and POAG red blood cells, a number of these phospholipids are absent locally (AQH).

Aqueous humor phospholipids of DBA/2J and DBA/2J-Gpnmb+/SjJ mice

“…2A), which is consistent with similar observations in human AH between control and POAG donors[15]. The number of common, total and unique lipids in each state that contributed to the total amount has been presented in Fig.…”

“…The scans ranged from 200 to 1000 m/z. The parameters and quantitative phospholipid standards for quantifying each specific phospholipid were used based on previous studies[14,15]. Briefly, PCs were analyzed in positive ion mode with a parent ion scan (PIS) of 184 m/z at 35 V, PE was analyzed in negative ion mode with a PIS of 196 m/z at 50 V, PI was analyzed in negative ion mode with a PIS of 241 m/z at 45 V, and PS was analyzed in negative ion mode with a neutral loss scan (NLS) of 87.1 m/z at 24 V. The 0.1% formic acid (FA) was used as an additive method for analyses of lipids in the positive ion mode only (that is, for analyses of PC but not for PS, PE or PI).…”

Sphingolipids and ceramides of mouse aqueous humor: Comparative profiles from normotensive and hypertensive DBA/2J mice

“…Changes in phospholipids with concomitant changes in enzymatic activities have been found in the TM [32]. Significant phospholipid changes were also found in the AH between normal control and glaucomatous human subjects [12], which could potentially attributed to altered enzymatic activities for these lipids in the TM as noted above and possibly in other surrounding tissues as well. Whether activity of key enzymes in the sphingolipid pathway are also impaired in transition from normotensive to a hypertensive state remains to be investigated.…”

Phospholipid makeup of the breast adipose tissue is impacted by obesity and mammary cancer in the mouse: Results of a pilot study

“…An aliquot of 100 uL for each sample was suspended in 200 uL mixture of Acetonitrile: Isopropanol (1:1) solution (Sigma Aldrich) and directly infused into the mass spectrometer. Lipid class settings were determined from previously published papers [18–20,22–25] and analysis was performed for each of the phospholipids. A nanospray was used (Advion, Ithaca, NY) for infusion.…”

“…850725) for PEs and 1,2-dioleoyl-sn-glycero-3-phospho-(10-myo-inositol) (molecular mass 880.15, catalog no. 850149) for PIs [22,25]. Also, samples were analyzed without standards in order to ensure that the mass by charge (m/z) of the standard was not a normal constituent of the biological tissue.…”