Effects of A379V variant of the Lp-PLA 2 gene on Lp-PLA 2 activity and markers of oxidative stress and endothelial function in Koreans

Association of Serum Lipoprotein-Associated Phospholipase A2 and A379V Gene Polymorphisms with Carotid Plaques

Objective: Lipoprotein-associated phospholipase A2 (LP-PLA2) is closely related to the development of atherosclerosis. The A379V gene polymorphism, located in exon 11 of the PLA2G7 gene, can affect LP-PLA2 levels and the inflammatory response. However, the association between the A379V polymorphism and formation of carotid plaques is unclear. Materials and Methods: A total of 516 ischemic stroke patients were classified according to carotid intima-media thickness as measured by ultrasound into the plaque group (n = 375, including 258 and 117 cases having vulnerable and stable plaques, respectively) and the nonplaque group (n = 141). The LP-PLA2 gene A379V polymorphism was determined by DNA sequencing, and Lp-PLA2 serum protein levels were determined simultaneously. Results: The serum Lp-PLA2 levels (p < 0.0005), CT+TT genotype frequency (odds ratio [OR]: 1.730, 95% confidence interval [CI]: 1.114-2.686, p = 0.014), and T allele frequency (OR: 1.592, 95% CI: 1.082-2.342, p = 0.018) in the plaque group were significantly higher than those in the nonplaque group. Lp-PLA2 serum levels in the vulnerable plaque subgroup were significantly higher than those in the stable plaque subgroup (p = 0.003). However, there were no significant differences in the frequency of the A379V polymorphism between the vulnerable and stable plaque subgroups. For all subjects, Lp-PLA2 serum levels for patients having a CC genotype were significantly lower than those for patients having a CT (p = 0.003), TT (p = 0.014), or CC+TT genotype (p = 0.001). Logistic regression showed that the Lp-PLA2 level was a risk factor for carotid plaque formation (OR: 1.024, 95% CI: 1.011-1.030, p = 0.001), but the A379V gene polymorphism was not (OR: 1.037, 95% CI: 0.357-3.012, p = 0.947). Conclusion: The A379V gene polymorphism might be associated with serum Lp-PLA2 levels and carotid plaque formation, but not with plaque vulnerability in a Chinese Han population. Serum Lp-PLA2 level was shown to be a risk factor for carotid plaque formation.

Lipoprotein-associated phospholipase A2: The story continues

Inflammation is thought to play an important role in the pathogenesis of vascular diseases. Lipoprotein-associated phospholipase A2 (Lp-PLA2) mediates vascular inflammation through the regulation of lipid metabolism in blood, thus, it has been extensively investigated to identify its role in vascular inflammation-related diseases, mainly atherosclerosis. Although darapladib, the most advanced Lp-PLA2 inhibitor, failed to meet the primary endpoints of two large phase III trials in atherosclerosis patients cotreated with standard medical care, the research on Lp-PLA2 has not been terminated. Novel pathogenic, epidemiologic, genetic, and crystallographic studies regarding Lp-PLA2 have been reported recently, while novel inhibitors were identified through a fragment-based lead discovery strategy. More strikingly, recent clinical and preclinical studies revealed that Lp-PLA2 inhibition showed promising therapeutic effects in diabetic macular edema and Alzheimer's disease. In this review, we not only summarized the knowledge of Lp-PLA2 established in the past decades but also emphasized new findings in recent years. We hope this review could be valuable for helping researchers acquire a much deeper insight into the nature of Lp-PLA2, identify more potent and selective Lp-PLA2 inhibitors, and discover the potential indications of Lp-PLA2 inhibitors.