Lipoprotein(a)-60 Years Later-What Do We Know?

A whole-animal phenotypic drug screen identifies suppressors of atherogenic lipoproteins

Lipoproteins are essential for lipid transport in all bilaterians. A single Apolipoprotein B (ApoB) molecule is the inseparable structural scaffold of each ApoB-containing lipoprotein (B-lps), which are responsible for transporting lipids to peripheral tissues. The cellular mechanisms that regulate ApoB and B-lp production, secretion, transport, and degradation remain to be fully defined. In humans, elevated levels of vascular B-lps play a causative role in cardiovascular disease. Previously, we have detailed that human B-lp biology is remarkably conserved in the zebrafish using an in vivo chemiluminescent reporter of ApoB (LipoGlo) that does not disrupt ApoB function. Thus, the LipoGlo model is an ideal system for identifying novel mechanisms of ApoB modulation and, due to the ability of zebrafish to generate many progeny, is particularly amenable to large-scale phenotypic drug screening. Here, we report a screen of roughly 3000 compounds that identified 49 unique ApoB-lowering hits. Nineteen hits passed orthogonal screening criteria. A licorice root component, enoxolone, significantly lowered B-lps only in animals that express a functional allele of the nuclear hormone receptor Hepatocyte Nuclear Factor 4⍺ (HNF4⍺). Consistent with this result, inhibitors of HNF4⍺ also reduce B-lp levels. These data demonstrate that mechanism(s) of action can be rapidly determined from a whole animal zebrafish phenotypic screen. Given the well documented role of HNF4⍺ in human B-lp biology, these data validate the LipoGlo screening platform for identifying small molecule modulators of B-lps that play a critical role in a leading cause of worldwide mortality.

Exploring the Relationship Between Lipoprotein (a) Level and Myocardial Infarction Risk: An Observational Study

Background and Objectives: This observational study investigates the relationship between Lipoprotein (a) (Lp(a)) levels and the risk of acute myocardial infarction (AMI). This study aims to highlight the association of elevated Lipoprotein (a) levels with an increased atherogenic profile and the potential risk of AMI. Materials and Methods: We conducted a case-control study involving 106 individuals, including 64 AMI patients (both STEMI and NSTEMI) and 42 healthy controls. Comprehensive clinical and biochemical assessments, including Lp(a) measurements, were conducted. Results: Patients with Lp(a) levels ≥ 30 mg/dL had a threefold increased risk of AMI compared to those with lower levels, independent of traditional risk factors such as cholesterol, smoking, and body weight. Elevated Lp(a) was observed in 50% of AMI patients compared to 28.57% in controls (p = 0.028). Notably, a multivariate analysis identified high Lp(a) levels, low HDL-C levels, and obesity as significant independent predictors of AMI, indicating these factors may contribute to AMI risk more prominently than other conventional risk factors in patients with elevated Lp(a). Moreover, the association between Lp(a) and AMI risk was consistent across various patient subgroups, with low HDL-C further compounding the risk. Conclusions: Lp(a) is a significant independent risk factor for acute myocardial infarction; therefore, screening for Lp(a) levels can help identify high-risk individuals beyond traditional markers. Therapeutic approaches targeting Lp(a) may reduce AMI incidence. Future research should explore how Lp(a) promotes atherosclerosis and assess Lp(a)-lowering therapies to improve patient outcomes.

Correlation Between Lipoprotein(a) and Prognosis for Coronary Artery Disease in Patients Undergoing Percutaneous Coronary Intervention

Background

Elevated lipoprotein(a) (Lp[a]) is a risk factor for first atherosclerotic thrombosis events, but the role of elevated Lp(a) in secondary prevention is controversial. This study aimed to retrospectively investigate the influence of elevated Lp(a) levels on the prognosis of patients with coronary artery disease.

Methods

The team collected and compared clinical information of patients hospitalized during percutaneous coronary intervention (PCI). This study used a multivariate logistic regression model to evaluate the relationships between Lp(a) levels, cardiovascular risk factors, and the prognosis of coronary artery disease in patients undergoing PCI.

Results

There were no statistically significant differences between patients grouped according to Lp(a) level in terms of sex; age; body mass index and obesity; hyperuricemia; smoking; cardiac insufficiency; acute myocardial infarction; multivessel lesion; in-stent restenosis; secondary PCI; apolipoprotein AI level; incidence of high total cholesterol or high low-density lipoprotein cholesterol; or family history of hypertension, diabetes, or coronary artery disease. The average Lp(a) concentration did not statistically significantly decrease after 1 year of statin treatment after PCI. One year after patients began statins, there were no significant differences between Lp(a) groups in the incidence of high triglycerides (P = .13), high total cholesterol (P = .52), or high low-density lipoprotein cholesterol (P = .051). Multivariate logistic regression analysis indicated that diabetes (P = .02) was associated with in-stent restenosis, whereas diabetes (P = .02) and multivessel lesions (P < .001) were associated with secondary PCI in patients who underwent coronary angiography 1 year after PCI. Compared with normal Lp(a) levels, high Lp(a) levels did not significantly increase the incidence of in-stent restenosis or secondary PCI in patients who underwent coronary angiography 1 year after PCI.

Conclusion

Sustained high concentrations of Lp(a) did not significantly increase the incidence of in-stent restenosis or secondary PCI in patients who underwent coronary angiography 1 year after PCI.

Fragment-based drug design of novel inhibitors targeting lipoprotein (a) kringle domain KIV-10-mediated cardiovascular disease

Cardiovascular diseases (CVDs) are the leading cause of death globally, attributed to a complex etiology involving metabolic, genetic, and protein-related factors. Lipoprotein(a) (Lp(a)), identified as a genetic risk factor, exhibits elevated levels linked to an increased risk of cardiovascular diseases. The lipoprotein(a) kringle domains have recently been identified as a potential target for the treatment of CVDs, in this study we utilized a fragment-based drug design approach to design a novel, potent, and safe inhibitor for lipoprotein(a) kringle domain. With the use of fragment library (61,600 fragments) screening, combined with analyses such as MM/GBSA, molecular dynamics simulation (MD), and principal component analysis, we successfully identified molecules effective against the kringle domains of Lipoprotein(a). The hybridization process (Breed) of the best fragments generated a novel 249 hybrid molecules, among them 77 exhibiting superior binding affinity (≤ -7 kcal/mol) compared to control AZ-02 (-6.9 kcal/mol), Importantly, the top ten molecules displayed high similarity to the control AZ-02. Among the top ten molecules, BR1 exhibited the best docking energy (-11.85 kcal/mol ), and higher stability within the protein LBS site, demonstrating the capability to counteract the pathophysiological effects of lipoprotein(a) [Lp(a)]. Additionally, principal component analysis (PCA) highlighted a similar trend of motion during the binding of BR1 and the control compound (AZ-02), limiting protein mobility and reducing conformational space. Moreover, ADMET analysis indicated favorable drug-like properties, with BR1 showing minimal violations of Lipinski's rules. Overall, the identified compounds hold promise as potential therapeutics, addressing a critical need in cardiovascular medicine. Further preclinical and clinical evaluations are needed to validate their efficacy and safety, potentially ushering in a new era of targeted therapies for CVDs.

Sex X Time Interactions in Lp(a) and LDL-C Response to Evolocumab

The aim of this study was to evaluate whether there were significant sex x time interactions in lipoprotein(a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) response to treatment with the Proprotein Convertase Subtilisin/Kexin type 9 inhibitor (PCSK9i) Evolocumab, in a real-life clinical setting. For this purpose, we pooled data from 176 outpatients (Men: 93; Women: 83) clinically evaluated at baseline and every six months after starting Evolocumab. Individuals who had been on PCSK9i for less than 30 months and nonadherent patients were excluded from the analysis. Over time, absolute values of Lp(a) plasma concentrations significantly decreased in the entire cohort (p-value < 0.001) and by sex (p-value < 0.001 in men and p-value = 0.002 in and women). However, there were no sex-related significant differences. Absolute plasma concentrations of LDL-C significantly decreased over time in the entire cohort and by sex (p-value < 0.001 always), with greater improvements in men compared to women. The sex x time interaction was statistically significant in LDL-C (all p-values < 0.05), while absolute changes in Lp(a) were not influenced by either sex or time (all p-value > 0.05). Our data partially reinforce the presence of differences in response to treatment to PCSK9i between men and women and are essential to gain a better understanding of the relationship between LDL-C and Lp(a) lowering in response to PCSK9i. Further research will clarify whether these sex-related significant differences translate into a meaningful difference in the long-term risk of ASCVD.