darapladib and Dyslipidemias

 Lipoprotein-associated phospholipase A2 (Lp-PLA2) is being evaluated as a therapeutic target for treatment of atherosclerosis. This is the first study to examine the effects of darapladib, a novel selective Lp-PLA2 inhibitor, on Lp-PLA2 activity in Japanese dyslipidemic patients with/without the Val279Phe (V279F) single-nucleotide polymorphism (SNP) of the PLA2G7 gene. Exploratory analysis to examine the effects of V279F on Lp-PLA2 inhibition of darapladib was also performed..  This was a 4-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging trial of darapladib in 107 Japanese patients with dyslipidemia receiving statins. Patients were randomized to placebo (n=25), darapladib 40 mg (n=28), 80 mg (n=28), or 16 0mg (n=26). All darapladib doses produced sustained dose-dependent inhibition of Lp-PLA2 activity of approximately 49%, 58%, and 67%, respectively (P<0.001 for all comparisons). The inhibitory effect achieved a plateau by 1 week. Patients with the V279F homogenous mutation who have no circulating levels of Lp-PLA2, were excluded from the study. The Lp-PLA2 activity was inhibited in both homozygous wild-type and heterozygote genotypes of the V279F polymorphism subjects to a similar extent, although the heterogeneous mutation has almost half the level of Lp-PLA2 activity compared with that of wild-type in Japanese people. The most common adverse events were odor related. No major safety concerns were noted..  Darapladib produced sustained inhibition of Lp-PLA2 activity in Japanese dyslipidemic patients with/without the V279F SNP of Lp-PLA2.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Adult; Aged, 80 and over; Amino Acid Substitution; Asian People; Benzaldehydes; Dose-Response Relationship, Drug; Double-Blind Method; Dyslipidemias; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Japan; Male; Middle Aged; Mutation, Missense; Oximes; Phospholipase A2 Inhibitors; Phospholipases A2; Polymorphism, Single Nucleotide

Atherosclerosis is a chronic inflammatory disease which may lead to major cardiovascular events. The primary cause of atherosclerosis is Dyslipidemia. The increased level of lipid profile triggers endothelial dysfunction. This results in inflammation with the recruitment of monocyte, macrophage, T lymphocyte, and Mast cells secreted by an Lp-PLA2 enzyme which causes binding between macrophage and oxidized LDL. This binding results in the formation of foam cells and also the migration of smooth muscle cells. Following that, an Lp-PLA2 receptor hydrolizes OxPC which results in LysoPC and OxNEFA, bioactive compounds which stimulate the progression of atherosclerosis plaques. This process leads to cell hypoxia, which may result in the increase of HIF-1α and VEGF expressions and induction of vasa vasorum angiogenesis. Employing darapladib as an agent of Lp-PLA2 selective inhibitors, this study aimed to find out the effect of darapladib as an Lp- PLA2 selective inhibitor agent on the formation of vasa vasorum angiogenesis and the decrease of HIF-1α and VEGF expression in aortic tissue of rats with dyslipidemia.. A true laboratory experiment with a randomized post-test control group design used 30 male spraque dowley rats as animal models which were divided into 6 groups: Normal 8 weeks, Normal 16 weeks, Dyslipidemia (DL) 8 weeks, Dyslipidemia (DL) 16 weeks, Dyslipidemia with darapladib treatment (DLDP) 8 weeks and Dyslipidemia with darapladib treatment (DLDP) 16 weeks. The data measured in this study were the lipid profile (total cholesterol, HDL, and LDL). Using EnzyChrom TM kit, hematoxylin eosin, and double-labelling immunofluorescene, the levels of lipid profile, vasa vasorum, HIF-1α and VEGF were measured.. The study results which were analyzed using NOVA test showed that with darapladib administration, there was a significant decrease in vasa vasorum angiogenesis (p=0.000), HIF-1α (p=0.005) and VEGF (p=0.009) expression in each time series. This result proves that Lp-PLA2 inhibitor reduces inflammatory process.. Darapladib injection as an Lp-PLA2 selective inhibitor correlates with the decreasing vasa vasorum angiogenesis through alteration in HIF-1α and VEGF expressions in the aorta of high fat diet rats. We recommend further experiments to determine the effectiveness of darapladib with earlier time series in the atherosclerosis process.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Animals; Atherosclerosis; Benzaldehydes; Dyslipidemias; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Neovascularization, Pathologic; Oximes; Rats, Sprague-Dawley; Vasa Vasorum; Vascular Endothelial Growth Factor A