Protective Role of Sphingomyelin in Eye Lens Cell Membrane Model against Oxidative Stress.

In the eye lens cell membrane, the lipid composition changes during the aging process: the proportion of sphingomyelins (SM) increases, that of phosphatidylcholines decreases. To investigate the protective role of the SMs in the lens cell membrane against oxidative damage, analytical techniques such as electrochemistry, high-resolution mass spectrometry (HR-MS), and atomic force microscopy (AFM) were applied. Supported lipid bilayers (SLB) were prepared to mimic the lens cell membrane with different fractions of PLPC/SM (PLPC: 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine).

Sphingomyelins Prevent Propagation of Lipid Peroxidation-LC-MS/MS Evaluation of Inhibition Mechanisms.

Free radical driven lipid peroxidation is a chain reaction which can lead to oxidative degradation of biological membranes. Propagation vs. termination rates of peroxidation in biological membranes are determined by a variety of factors including fatty acyl chain composition, presence of antioxidants, as well as biophysical properties of mono- or bilayers.

Single Cell Analysis by High-Resolution Atmospheric-Pressure MALDI MS Imaging.

Complementary to other imaging techniques, MALDI MS imaging provides label-free analysis and chemical specificity, covering a wide range of molecules that can be visualized simultaneously. Here, we highlight a protocol to visualize lipids from single cardiac cells using high-resolution atmospheric-pressure matrix-assisted laser desorption/ionization coupled to an orbital trapping mass analyzer.

Impact of inhibition of the autophagy-lysosomal pathway on biomolecules carbonylation and proteome regulation in rat cardiac cells.

Cells employ multiple defence mechanisms to sustain a wide range of stress conditions associated with accumulation of modified self-biomolecules leading to lipo- and proteotoxicity. One of such mechanisms involves activation of the autophagy-lysosomal pathway for removal and degradation of modified lipids, proteins and even organelles. Biomolecules carbonylation, an irreversible oxidative modification, occurs in a variety of pathological conditions and is generally viewed as a marker of oxidative stress.

Chiral capillary electrophoresis with UV-excited fluorescence detection for the enantioselective analysis of 9-fluorenylmethoxycarbonyl-derivatized amino acids.

The potential of capillary electrophoresis (CE) with ultraviolet (UV)-excited fluorescence detection for sensitive chiral analysis of amino acids (AAs) was investigated. DL-AAs were derivatized with 9-fluorenylmethoxycarbonyl chloride (FMOC)-Cl to allow their fluorescence detection and enhance enantioseparation. Fluorescence detection was achieved employing optical fibers, leading UV excitation light (< 300 nm) from a Xe-Hg lamp to the capillary window, and fluorescence emission to a spectrograph equipped with a charge-coupled device (CCD).