Purification of an Acidic Polysaccharide with Anticoagulant Activity from the Marine Sponge Sarcotragus spinosulus.

Thromboembolic conditions are the most common cause of death in developed countries. Anticoagulant therapy is the treatment of choice, and heparinoids and warfarin are the most adopted drugs. Sulphated polysaccharides extracted from marine organisms have been demonstrated to be effective alternatives, blocking thrombus formation by inhibiting some factors involved in the coagulation cascade. In this study, four acidic glycan fractions from the marine sponge Sarcotragus spinosulus were purified by anion-exchange chromatography, and their anticoagulant properties were investigated through APTT and PT assays and compared with both standard glycosaminoglycans and holothurian sulphated polysaccharides. Moreover, their topographic localization was assessed through histological analysis, and their cytocompatibility was tested on a human fibroblast cell line. A positive correlation between the amount of acid glycans and the inhibitory effect towards both the intrinsic and extrinsic coagulation pathways was observed. The most effective anticoagulant activity was shown by a highly charged fraction, which accounted for almost half (about 40%) of the total hexuronate-containing polysaccharides. Its preliminary structural characterization, performed through infrared spectroscopy and nuclear magnetic resonance, suggested that it may consist of a fucosylated chondroitin sulphate, whose unique structure may be responsible for the anticoagulant activity reported herein for the first time.

Molecular Characterization of Plasma HDL, LDL, and VLDL Lipids Cargos from Atherosclerotic Patients with Advanced Carotid Lesions: A Preliminary Report.

Carotid atherosclerosis represents a relevant healthcare problem, since unstable plaques are responsible for approximately 15% of neurologic events, namely transient ischemic attack and stroke. Although statins treatment has proven effective in reducing LDL-cholesterol and the onset of acute clinical events, a residual risk may persist suggesting the need for the detection of reliable molecular markers useful for the identification of patients at higher risk regardless of optimal medical therapy. In this regard, several lines of evidence show a relationship among specific biologically active plasma lipids, atherosclerosis, and acute clinical events. We performed a Selected Reaction Monitoring-based High Performance Liquid Chromatography-tandem Mass Spectrometry (SRM-based HPLC-MS/MS) analysis on plasma HDL, LDL, and VLDL fractions purified, by isopycnic salt gradient ultracentrifugation, from twenty-eight patients undergoing carotid endarterectomy, having either a "hard" or a "soft" plaque, with the aim of characterizing the specific lipidomic patterns associated with features of carotid plaque instability. One hundred and thirty lipid species encompassing different lipid (sub)classes were monitored. Supervised multivariate analysis showed that lipids belonging to phosphatidylethanolamine (PE), sphingomyelin (SM), and diacylglycerol (DG) classes mostly contribute to discrimination within each lipoprotein fraction according to the plaque typology. Differential analysis evidenced a significant dysregulation of LDL PE (38:6), SM (32:1), and SM (32:2) between the two groups of patients (adj. p-value threshold = 0.05 and log2FC ≥ |0.58|). Using this approach, some LDL-associated markers of plaque vulnerability have been identified, in line with the current knowledge of the key roles of these phospholipids in lipoprotein metabolism and cardiovascular disease. This proof-of-concept study reports promising results, showing that lipoprotein lipidomics may present a valuable approach for identifying new biomarkers of potential clinical relevance.