Chemical analysis of C-reactive protein synthesized by human aortic endothelial cells under oxidative stress.

C-reactive protein (CRP) is a clinical biomarker of inflammation, and high levels of CRP correlate with cardiovascular disease. The objectives of this study were to test our hypothesis that oxidized low-density lipoprotein (ox-LDL) induces the release of CRP from human aortic endothelial cells (HAECs) and to optimize several analytical methods to identify CRP released from cultured cells in a model of atherogenic stress. HAECs were incubated with copper-oxidized LDL, and the supernatant was subsequently purified by diethylaminoethyl chromatography and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Analysis of in vitro oxidized human LDL phospholipids by solid-phase extraction and micellar electrokinetic capillary chromatography.

Phospholipids of in vitro oxidized human low-density lipoproteins (LDL) were separated by two different solid-phase extraction (SPE) methods. One of the two methods was designed to test the effects of gradient elution. This SPE method isolated more phospholipids from in vitro oxidized LDL than the other one according to the results of liquid chromatography and electrospray ionization mass spectrometry (LC ESI-MS) analysis.

Micellar electrokinetic chromatography profiles of human high-density lipoprotein phospholipids.

A simple and fast micellar electrokinetic chromatography (MEKC) method was developed to investigate phospholipids isolated from human high-density lipoproteins (HDL). To optimize the MEKC conditions, several factors including bile salt concentration and organic modifier concentration in the separation buffer as well as temperature have been examined. The optimal separation buffer chosen was a mixture of 50 mM bile salts, 30% v/v 1-propanol and 10 mM sodium phosphate (pH 8.

Characterization of in vitro modified human high-density lipoprotein particles and phospholipids by capillary zone electrophoresis and LC ESI-MS.

A simple capillary zone electrophoresis (CZE) method was used to characterize native, in vitro oxidized and glycated human high-density lipoprotein (HDL) particles. Both native and in vitro oxidized HDL capillary electrophoresis (CE) profiles showed a major peak, but the oxidized HDL particles had higher effective mobilities. The in vitro glycated HDL particles showed a major peak and one or two minor peaks.