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Background: Platelets play an important role in hemostasis, thrombosis, and atherosclerosis. Glycoprotein VI (GPVI) is a major platelet receptor that interacts with exposed collagen on injured vessel walls. Our previous studies have shown that anthocyanins (a type of natural plant pigment) attenuate platelet function; however, whether anthocyanins affect collagen-induced GPVI signaling remains unknown.Objective: The objective of this study was to explore the effects of cyanidin-3-glucoside (Cy-3-g, one of the major bioactive compounds in anthocyanins) on platelet activation and thrombosis and the GPVI signaling pathway.Methods: Platelets from healthy men and women were isolated and incubated with different concentrations (0, 0.5, 5, and 50 μM) of Cy-3-g. The expression of activated integrin αIIbβ3, P-selectin, CD63, and CD40L, fibrinogen binding to platelets, and platelet aggregation were evaluated in vitro. Platelet adhesion and aggregation in whole blood under flow conditions were assessed in collagen-coated perfusion chambers. Thrombosis and hemostasis were assessed in 3-4-wk-old male C57BL/6J mice through FeCl3-induced intravital microscopy and tail bleeding time. The effect of Cy-3-g on collagen-induced human platelet GPVI signaling was explored with Western blot.Results: Cy-3-g attenuated platelet function in a dose-dependent manner. The 0.5-μM dose of Cy-3-g inhibited (P < 0.05) human platelet adhesion and aggregation to collagen at both venous (-54.02%) and arterial (-22.90%) shear stresses. The 5-μM dose inhibited (P < 0.05) collagen-induced human platelet activation (PAC-1: -48.21%, P-selectin: -50.63%), secretion (CD63: -73.89%, CD40L: -43.70%), fibrinogen binding (-56.79%), and aggregation (-17.81%). The 5-μM dose attenuated (P < 0.01) thrombus growth (-66.67%) without prolonging bleeding time in mice. The 50-μM dose downregulated (P < 0.05) collagen-induced GPVI signaling in human platelets and significantly decreased phosphorylation of Syk-linker for activation of T cells (LAT)-SLP76 (Syk: -39.08%, LAT: -32.25%, SLP76: -40.00%) and the expression of Lyn (-31.89%), Fyn (-36.27%), and phospholipase C-γ2 (-39.08%).Conclusions: Cy-3-g inhibits human platelet activation, aggregation, secretion, and thrombus formation, and downregulates the collagen-GPVI signaling pathway. Supplementation of Cy-3-g may have protective effects against atherothrombosis. [ABSTRACT FROM AUTHOR]

O-antigen is part of the lipopolysaccharide present in the outer membrane of Gram-negative bacteria, and contributes the major antigenic variability to the cell surface. Screening for the Escherichia coli O-serogroup is the conventional method for identifying E. coli clones. In this study, we investigated the structural characteristics of the E. coli O99 O-antigen and the organization of the genes involved in its synthesis. On the basis of sugar and methylation analysis and nuclear magnetic resonance spectroscopy data, we established the structure of the branched hexasaccharide repeat unit of the O-polysaccharide. This unit consists of fourd-rhamnose (d-Rha) moieties in the backbone and twod-glucose (d-Glc) moieties in the side chain, as shown below: The O-antigen gene cluster of E. coli O99, which was located between galF and gnd, was found to contain putative genes for the synthesis ofd-Rha, genes encoding sugar transferases, and ATP-binding cassette (ABC) transporter genes ( wzm and wzt). Our findings indicate that in E. coli O99, the synthesis and translocation of the O-antigen occurs by an ABC transporter-dependent process. [ABSTRACT FROM AUTHOR]

Abstract: Ginsenosides, the active components found in Panax ginseng, have been reported to inhibit the cardiac hypertrophy in rats. This study aims to observe the potential effect of total ginsenosides (TG) on the hypertrophic vascular diseases. The model of vascular neointimal hyperplasia was established by rubbing the endothelia of the common carotid artery with a balloon in male Sprague Dawley rats. TG (15mg/kg/day, 45mg/kg/day), L-arginine (L-arg) 200mg/kg/day, and NG-nitro-L-arginine-methyl ester (L-NAME) 100mg/kg/day used with the same dose of L-arg or TG 45mg/kg/day were given for 7 and 14 consecutive days after surgery. TG and L-arg administrations significantly ameliorated the histopathology of injured carotid artery, which was abolished or blunted by L-NAME, an NOS inhibitor; TG and L-arg could also remarkably reduce the expression of proliferating cell nuclear antigen (PCNA), a proliferation marker of vascular smooth muscle cells(VSMCs), in neointima of the injured artery wall. Further study indicated that balloon injury caused a decreased superoxide dismutase (SOD) activity and an elevated malondialdehyde (MDA) content in plasma, and reduced the cGMP level in the artery wall, which were reversed by TG. It was concluded that TG suppress the rat carotid artery neointimal hyperplasia induced by balloon injury, which may be involved in its anti-oxidative action and enhancing the inhibition effects of NO/cGMP on VSMC proliferation. [Copyright &y& Elsevier]

The article presents a study that investigates the structure of the O-antigen of Salmonella O66 and the differences and similarities between the O-antigens of Salmonella O66 and Escherichia coli O166. It states that the O-antigen of Salmonella O66 differs from those of Escherichia coli O166 in one linkage and O-acetylation. The study has found out that the O-antigen gene clusters of Escherichia coli O166 and Salmonella O66 have similar organizations, except in their wzy genes.