ALOX5AP gene variants show differential association with coronary artery disease in different populations

Coronary artery disease (CAD) is a complex disease with various components, genetic as well as environmental. Previous reports correlating ALOX5AP gene variants and CAD showed conflicting results depending on the population studied. In this study, we examined the contribution of ALOX5AP genetic predisposition to CAD in a group of CAD patients and controls carefully selected from the Lebanese population. We genotyped SNPs for ALOX5AP variants in 289 catheterized patients aged ≤52 years with >50% stenosis in at least one main coronary artery and 227 catheterized control subjects aged 60 years and above with 0% stenosis. Chi-square (χ2) tests and logistic regression showed no significant difference in the allele and genotype frequencies between the CAD or myocardial infarction (MI) cases and the healthy controls. Haplotype analysis using PHASE showed that the distribution of the risk haplotypes among cases and controls were not significantly different and had no attributable risk to CAD (P = 1.00 and P = 0.5, respectively) or MI (P = 0.2 and P = 0.5, respectively). Our data revealed that ALOX5AP gene variants are not predictors of CAD risk or MI risk among Lebanese patients

Mouse Aorta Smooth Muscle Cells Differentiate Into Lymphoid Tissue Organizer-Like Cells on Combined Tumor Necrosis Factor Receptor-1/Lymphotoxin beta-Receptor NF-kappa B Signaling

OBJECTIVE: Mouse aorta smooth muscle cells (SMC) express tumor necrosis factor receptor superfamily member 1A (TNFR-1) and lymphotoxin β-receptor (LTβR). Circumstantial evidence has linked the SMC LTβR to tertiary lymphoid organogenesis in hyperlipidemic mice. Here, we explored TNFR-1 and LTβR signaling in cultured SMC. METHODS AND RESULTS: TNFR-1 signaling activated the classical RelA NF-κB pathway, whereas LTβR signaling activated the classical RelA and alternative RelB NF-κB pathways, and both signaling pathways synergized to enhance p100 inhibitor processing to the p52 subunit of NF-κB. Microarrays showed that simultaneous TNFR-1/LTβR activation resulted in elevated mRNA encoding leukocyte homeostatic chemokines CCL2, CCL5, CXCL1, and CX3CL1. Importantly, SMC acquired features of lymphoid tissue organizers, which control tertiary lymphoid organogenesis in autoimmune diseases through hyperinduction of CCL7, CCL9, CXCL13, CCL19, CXCL16, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. TNFR-1/LTβR cross-talk resulted in augmented secretion of lymphorganogenic chemokine proteins. Supernatants of TNFR-1/LTβR–activated SMC markedly supported migration of splenic T cells, B cells, and macrophages/dendritic cells. Experiments with ltbr(−/−) SMC indicated that LTβR-RelB activation was obligatory to generate the lymphoid tissue organizer phenotype. CONCLUSION: SMC may participate in the formation of tertiary lymphoid tissue in atherosclerosis by upregulation of lymphorganogenic chemokines involved in T-lymphocyte, B-lymphocyte, and macrophage/dendritic cell attraction

Ascorbic acid 6-palmitate: A potent inhibitor of human and soybean lipoxygenase-dependent lipid peroxidation

Objectives Lipoxygenases (LOX) are the key enzymes involved in the biosynthesis of leukotrienes and reactive oxygen species, which are implicated in pathophysiology of inflammatory disorders. This study was conducted to evaluate the inhibitory effect of water-soluble antioxidant ascorbic acid and its lipophilic derivative, ascorbic acid 6-palmitate (Vcpal) on polymorphonuclear lymphocyte 5-LOX and soybean 15-LOX (sLOX) in vitro. Methods LOX activity was determined by measuring the end products, 5-hydroperoxy eicosatetraenoic acid (5-HETE) and lipid hydroperoxides, by spectrophotometric and high performance liquid chromatography methods. The substrate-dependent enzyme kinetics and docking studies were carried out to understand the nature of inhibition. Key findings Vcpal potently inhibited 5-LOX when compared with its inhibitory effect on sLOX (IC50; 2.5 and 10.3μm respectively, P= 0.003). Further, Vcpal inhibited 5-LOX more strongly than the known synthetic drugs: phenidone and nordihydroguaiaretic acid (P= 0.0007). Enzyme kinetic studies demonstrated Vcpal as a non-competitive reversible inhibitor of 5-LOX. In-silico molecular docking revealed high MolDock and Rerank score for Vcpal than ascorbic acid, complementing in-vitro results. Conclusion Both in-vitro and docking studies demonstrated Vcpal but not ascorbic acid as a non-competitive inhibitor of 5-LOX- and sLOX-induced lipid peroxidation, suggesting a key role for lipophilic nature in bringing about inhibition

Cysteinyl leukotriene signaling through perinuclear CysLT(1) receptors on vascular smooth muscle cells transduces nuclear calcium signaling and alterations of gene expression.

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