Extraction and purification of gangliosides from plasma and fibroblasts before analysis by thin layer chromatography

GM1 ganglioside protects against LPS-induced neuroinflammatory and oxidative responses by inhibiting the activation of Akt, TAK1 and NADPH oxidase in MG6 microglial cells

GM1 is a major brain ganglioside that exerts neurotrophic, neuroprotective and antineuroinflammatory effects. The aim of this study was to obtain insights into the antineuroinflammatory mechanisms of exogenous GM1 in lipopolysaccharide (LPS)-stimulated MG6 mouse transformed microglial cell line. First, we found that GM1 prevented the LPS-induced transformation of microglia into an amoeboid-like shape. GM1 treatment inhibited LPS-induced expression of inducible nitric oxide synthase, cyclooxygenase-2 (COX-2), and proinflammatory cytokines such as TNF-α, IL-1β and IL-6 in MG6 cells. In LPS-treated mice, GM1 also reduced striatal microglia activation and attenuated COX-2 expression. Subsequent mechanistic studies showed that GM1 suppressed LPS-induced nuclear translocation of nuclear factor κB (NF-κB) and activator protein-1 (AP-1), two critical transcription factors responsible for the production of proinflammatory mediators. GM1 exhibited antineuroinflammatory properties by suppressing Akt/NF-κB signaling and the activation of mitogen-activated protein kinases (MAPKs), including p38 MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK). Furthermore, GM1 suppressed LPS-induced activation of transforming growth factor-β-activated kinase 1 (TAK1) and NADPH oxidase 2 (NOX2), upstream regulators of the IκBα/NF-κB and MAPK/AP-1 signaling pathways. GM1 also inhibited NOX-mediated reactive oxygen species (ROS) production and protected against LPS-induced MG6 cell death, suggesting an antioxidant role of GM1. In conclusion, GM1 exerts both antineuroinflammatory and antioxidative effects by inhibiting Akt, TAK1 and NOX2 activation.

Ganglioside analysis in body fluids by liquid-phase separation techniques hyphenated to mass spectrometry

The expression of gangliosides in central nervous system is a few times higher than in the extraneural tissue, a characteristic highlighting their major role at this level. Although in very low amounts, gangliosides are ubiquitously distributed in body fluids too, where, depending on many factors, including pathological states, their composition fluctuates, thus having diagnostic value. Ganglioside investigation in biological fluids, which, except for cerebrospinal fluid (CSF), may be sampled noninvasively, was for years impeded by the limited sensitivity of the analytical instrumentation available in glycomics. However, because the last decade has witnessed significant developments in biological mass spectrometry (MS) and the hyphenated separation techniques, marked by a major increase in sensitivity, reproducibility, and data reliability, ganglioside research started to be focused on biofluid analysis by separation techniques coupled to MS. In this context, our review presents the achievements in this emerging field of gangliosidomics, with a particular emphasis on modern liquid chromatography (LC), thin-layer chromatography, hydrophilic interaction LC, and ion mobility separation coupled to high-performance MS, as well as the results generated by these systems and allied experimental procedures in profiling and structural analysis of gangliosides in healthy or diseased body fluids, such as CSF, plasma/serum, and milk.

Determination of urinary sulfatides and other lipids by combination of reversed-phase and thin-layer chromatographies

A fast and simple method for determination of sulfatides in the urine of patients with metachromatic leukodystrophy (MLD, arylsulfatase A deficiency) has been developed. The procedure consists of two steps: extraction of total urinary lipids by reversed-phase chromatography and their HPTLC separation. Two types of sorbents based on different matrixes were compared, of which the hydroxyethyl methacrylate C-18 type sorbent was found to be superior. Twenty-milliliter aliquots of urine are sufficient for the analysis. The technique is appropriate for simultaneous qualitative identification and semiquantitative densitometric determination and is suitable for routine work. The amount of sulfatides is expressed in relation to sphingomyelin, which copurifies with sulfatides and better reflects the level of membrane lipids in urine than commonly used parameters (creatinine, urine volume, etc.). The ranges were found to be 0.15-0.68 nmol sulfatide/nmol sphingomyelin for control individuals and 3.5-27.2 nmol sulfatide/nmol sphingomyelin for MLD patients. The excretion of sulfatides is pathonognomic for true MLD (due to the accumulation in kidney) and therefore its analysis is important for evaluation of suspected MLD cases including clinically and enzymatically atypical cases. The method is also useful as a complementary analysis for other lipidoses with high excretion of sphingolipids in urine (e.g., Fabry disease).