Cholesteryl Ester Transfer Protein Inhibitors as Agents to Reduce Coronary Heart Disease Risk

Identification and characterization of a rare variant in apolipoprotein A-IV, p.(V336M), and evaluation of HDL functionality in a Greek cohort with extreme HDL cholesterol levels

High-Density Lipoprotein cholesterol (HDL-C) levels do not correlate well with Coronary Artery Disease (CAD) risk, while HDL functionality affects atherogenesis and is a better prognostic marker for CAD. Often, the extreme HDL-C levels have a multigenic origin. Here, we searched for single-nucleotide polymorphisms (SNPs) in ten genes of HDL metabolism in a Greek cohort with very low (<10th percentile, n = 13) or very high (>90th percentile, n = 21) HDL-C. We also evaluated the association between HDL-C levels, HDL functionality (anti-oxidant capacity) and CAD in the subjects of this cohort. Individuals with low HDL-C levels had higher triglyceride levels, lower apoA-I levels, decreased HDL anti-oxidant capacity and higher incidence of CAD compared with individuals with control or high HDL-C levels. With next generation sequencing we identified 18 exonic SNPs in 6 genes of HDL metabolism and for selected amino acid changes we performed computer-aided structural analysis and modeling. A previously uncharacterized rare apolipoprotein A-IV variant, apoA-IV [V336M], present in a subject with low HDL-C (14 mg/dL) and CAD, was expressed in recombinant form and structurally and functionally characterized. ApoA-IV [V336M] had similar α-helical content to WT apoA-IV but displayed a small thermodynamic stabilization by chemical unfolding analysis. ApoA-IV [V336M] was able to associate with phospholipids but presented reduced kinetics compared to WT apoA-IV. Overall, we identified a rare apoA-IV variant in a subject with low HDL levels and CAD with altered biophysical and phospholipid binding properties and showed that subjects with very low HDL-C presented with HDL dysfunction and higher incidence of CAD in a Greek cohort.

Humoral Immunity Against HDL Particle: A New Perspective in Cardiovascular Diseases?

BACKGROUND

Autoimmune diseases are closely associated with cardiovascular diseases (CVD). Over the last decades, the comprehension of atherosclerosis, the principal initiator of CVD, evolved from a lipidcentered disease to a predominant inflammatory and immune response-driven disease displaying features of autoimmunity against a broad range of auto-antigens, including lipoproteins. Among them, high density lipoproteins (HDL) are important actors of cholesterol transport and bear several anti-atherogenic properties, raising a growing interest as therapeutic targets to decrease atherosclerosis and CVD burden, with nevertheless rather disappointing results so far. Reflecting HDL composition complexity, autoimmune responses and autoantibodies against various HDL components have been reported.

RESULTS

In this review, we addressed the important complexity of humoral autoimmunity towards HDL and particularly how this autoimmune response could help improving our understanding of HDL biological implication in atherosclerosis and CVD. We also discussed several issues related to specific HDL autoantibody subclasses characteristics, including etiology, prognosis and pathological mechanisms according to Rose criteria.

CONCLUSION

Finally, we addressed the possible clinical value of using these antibodies not only as potential biomarkers of atherogenesis and CVD, but also as a factor potentially mitigating the benefit of HDL-raising therapies.

Proprotein Convertase Subtilisin/Kexin Type 9, Angiopoietin-Like Protein 8, Sortilin, and Cholesteryl Ester Transfer Protein-Friends of Foes for Psoriatic Patients at the Risk of Developing Cardiometabolic Syndrome?

Psoriasis is a systemic, immune-metabolic disease with strong genetic predispositions and autoimmune pathogenic traits. During psoriasis progression, a wide spectrum of comorbidities comes into play with the leading role of the cardio-metabolic syndrome (CMS) that occurs with the frequency of 30–50% amongst the psoriatic patients. Both conditions—psoriasis and CMS—have numerous common pathways, mainly related to proinflammatory pathways and cytokine profiles. Surprisingly, despite the years of research, the exact pathways linking the occurrence of CMS in the psoriasis population are still not fully understood. Recently published papers, both clinical and based on the basic science, shed new light into this relationship providing an insight into novel key-players proteins with plausible effects on above-mentioned interplay. Taking into account recent advances in this important medical matter, this review aims to discuss comprehensively the role of four proteins: proprotein convertase subtilisin/kexin type-9 (PSCK9), angiopoietin-like protein 8 (ANGPLT8), sortilin (SORT1), and cholesteryl ester transfer proteins (CEPT) as plausible links between psoriasis and CMS.

Association of Serum Cholesterol Ester Transfer Protein Levels with Taq IB Polymorphism in Acute Coronary Syndrome

Information on the relationship between circulating cholesteryl ester transfer protein (CETP) levels and coronary heart disease (CHD) incidence (and also, therefore, acute coronary syndrome [ACS]) is conflicting. Many studies have been published concerning this relationship, most of which have incompatible results. In our study, we aimed to determine serum CETP levels in subject individuals with ACS and healthy control individuals, and the association of those levels with Taq IB polymorphism. The current study was conducted with 62 hospitalized patients who had been diagnosed with ACS and 26 controls. All subjects were selected from a previous study of which we are among the coauthors. Serum CETP levels were determined by quantitative enzyme-linked immunosorbent assay (ELISA). The mean serum CETP levels in all patients were significantly higher than those in controls. CETP TaqIB polymorphism affected serum CETP levels, with higher serum CETP for the GA genotype in both groups than in other genotypes. Although the AA genotype showed higher CETP levels than the GG genotype in patients with ACS, the GG showed higher CETP than the AA in healthy controls. Our results support an association between high serum CETP and ACS incidence. Our study helped address some of the controversies regarding the relationship of serum CETP mass to atherosclerosis, in addition to the association of ACS occurrence with circulating CETP levels.

High-Density Lipoproteins and Apolipoprotein A-I Improve Stent Biocompatibility

Revascularization because of coronary artery disease is commonly achieved by percutaneous coronary intervention with stent deployment. Refinement in interventional techniques, major improvements in stent design (particularly drug-eluting stents), and adjunctive pharmacotherapy with dual antiplatelet regimens have led to marked reductions in the overall rates of stent failure. However, even with the advancements made in the latest generation of drug-eluting stents, unresolved biological problems persist including delayed re-endothelialization and neoatherosclerosis, which can promote late expansion of the neointima and late stent thrombosis. Novel strategies are still needed beyond what is currently available to specifically address the pathobiological processes that underpin the residual risk for adverse clinical events. This review focuses on the emerging evidence that HDL (high-density lipoproteins) and its main apo (apolipoprotein), apoA-I, exhibit multiple vascular biological functions that are associated with an improvement in stent biocompatibility. HDL/apoA-I have recently been shown to inhibit in-stent restenosis in animal models of stenting and suppress smooth muscle cell proliferation in in vitro studies. Reconstituted HDL also promotes endothelial cell migration, endothelial progenitor cell mobilization, and re-endothelialization. Furthermore, reconstituted HDL decreases platelet activation and HDL cholesterol is inversely associated with the risk of thrombosis. Finally, reconstituted HDL/apoA-I suppresses key inflammatory mechanisms that initiate in-stent neoatherosclerosis and can efflux cholesterol from plaque macrophages, an important function of HDLs that prevents plaque progression. These unique multifunctional effects of HDL/apoA-I suggest that, if translated appropriately, have the potential to improve stent biocompatibility. This may provide an alternate and more efficacious therapeutic pathway for the translation of HDL.

Cynanchum wilfordii Etanolic Extract Controls Blood Cholesterol: A Double-blind, Randomized, Placebo-Controlled, Parallel Trial

We evaluated the effects of Cynanchum wilfordii (CW) ethanolic extract on blood cholesterol levels in adults with high low-density lipoprotein cholesterol (LDL-C) levels. In a double-blind, randomized, placebo-controlled, parallel trial, 84 subjects were recruited. Participants were randomly divided into two groups with a low-dose (300 mg/d) or high-dose (600 mg/d) of CW. Levels of very low-density lipoprotein (p = 0.022) and triglycerides (p = 0.022) were significantly lower in the low-dose CW group than in the placebo group after 8 weeks. In a subgroup of participants with LDL-C≥ 150 mg/dL (n = 33), there was a significant decrease in total cholesterol (low-dose, p = 0.012; high-dose, p = 0.021), apolipoprotein B (low-dose, p = 0.022; high-dose, p = 0.016), and cholesteryl ester transfer protein (low-dose, p = 0.037; high-dose, p = 0.016) after 8 weeks of CW. The correlation between changes in total cholesterol and baseline LDL-C levels was significant in the groups that received both doses of CW (low-dose, p = 0.010; high-dose, p = 0.015). These results show that the CW ethanolic extract can regulate blood cholesterol in subjects with LDL-C≥ 150 mg/dL.

Gender specific effect of CETP rs708272 polymorphism on lipid and atherogenic index of plasma levels but not on the risk of coronary artery disease: A case-control study

Numerous studies have shown a relationship between cholesteryl ester transfer protein (CETP) polymorphism in the synthesis of high-density lipoprotein cholesterol (HDL-C) and the coronary artery disease (CAD) susceptibility, but the results have remained inconsistent. In addition, there was no study exploring the relationship between CETP polymorphisms and atherogenic index of plasma (AIP) levels.We conducted a case-control study to evaluate the relationship between CETP rs708272 polymorphism and CAD risk and lipid levels in Chinese Han population. 556 CAD patients and 414 controls undergoing coronary angiography were consecutively enrolled in the hospital-based study. Polymerase chain reaction-ligase detection reaction (PCR-LDR) method was used to detect the different genotypes at rs708272.No significant association between CETP rs708272 polymorphism and CAD risk was observed in different genetic models. In the whole population, participants with TT genotype had higher HDL-C levels (1.17 ± 0.31 mmol/L vs 1.09 ± 0.29 mmol/L, P = .001) and lower AIP levels (0.08 ± 0.35 vs 0.16 ± 0.31, P = .004) compared to those with CC genotype, after adjusting for age, gender, smoking, essential hypertension (EH), and DM. The T allele carriers had higher HDL-C levels than the T allele non-carriers (1.13 ± 0.29 mmol/L vs 1.09 ± 0.29 mmol/L, P = .023). Furthermore, subgroup analyses based on gender were carried out. In males, the results showed that participants with TT genotype had significant higher HDL-C levels and lower AIP levels compared with CC genotype (P <.05). In addition, males with CT+TT genotypes had higher HDL-C levels and lower AIP levels than those with CC genotypes (HDL-C: CT+TT 1.11 ± 0.31vs CC 1.06 ± 0.30 mmol/L, P = .041; AIP: CT+TT 0.12 ± 0.32vs CC 0.16 ± 0.31, P = .034, respectively). However, there were no significant associations between lipid levels and CETP rs708272 polymorphism in females, after adjusting for confounders.CETP rs708272 polymorphism has a gender-specific effect on lipid and AIP levels but not on the risk of CAD.

Lipid lowering drugs and inflammatory changes: an impact on cardiovascular outcomes?

Inflammatory changes are responsible for maintenance of the atherosclerotic process and may underlie some of the most feared vascular complications. Among the multiple mechanisms of inflammation, the arterial deposition of lipids and particularly of cholesterol crystals is the one responsible for the activation of inflammasome NLRP3, followed by the rise of circulating markers, mainly C-reactive protein (CRP). Elevation of lipoproteins, LDL but also VLDL and remnants, associates with increased inflammatory changes and coronary risk. Lipid lowering medications can reduce cholesterolemia and CRP: patients with elevations of both are at greatest cardiovascular (CV) risk and receive maximum benefit from therapy. Evaluation of the major drug series indicates that statins exert the largest LDL and CRP reduction, accompanied by reduced CV events. Other drugs, mainly active on the triglyceride/HDL axis, for example, PPAR agonists, may improve CRP and the lipid pattern, especially in patients with metabolic syndrome. PCSK9 antagonists, the newest most potent medications, do not induce significant changes in inflammatory markers, but patients with the highest baseline CRP levels show the best CV risk reduction. Parallel evaluation of lipids and inflammatory changes clearly indicates a significant link, both guiding to patients at highest risk, and to the best pharmacological approach. Key messages Lipid lowering agents with "pleiotropic" effects provide a more effective approach to CV prevention In CANTOS study, patients achieving on-treatment hsCRP concentrations ≤2 mg/L had a higher benefit in terms of reduction in major CV events The anti-inflammatory activity of PCSK9 antagonists appears to be of a minimal extent.