PCSK9 Inhibition: From Current Advances to Evolving Future

Novel Jatrophane Diterpenoids from Euphorbia esula Promotes Lipid Clearance by Transcriptional Regulation of PCSK9

PCSK9 has been recognized as an efficient target for hyperlipidemia and related cardiovascular/cerebrovascular diseases. However, PCSK9 inhibitors in the clinic are all biological products, and no small molecules are available yet. In the current work, we discovered that the crude extract of Euphorbia esula (E. esula) promoted LDL uptake in vitro and then obtained 8 new and 12 known jatrophane diterpenoids by activity-guided isolation. After summarized their structure-activity relationship of PCSK9 inhibition, we selected compound 11 (C11) with potent activity and high abundance to investigate its mechanism and in vivo efficacy. Mechanistically, C11 bound with HNF1α to influence its nuclear distribution and subsequently inhibit PCSK9 transcription, thereby enhancing LDLR and promoting LDL uptake. Moreover, C11 demonstrated obvious lipid-lowering activity in HFD mouse model. In conclusion, we first revealed the novel application of E. esula in the discovery of a lipid-lowering candidate and highlighted the potential of C11 in the treatment of hyperlipidemia.

PCSK9 inhibition attenuates alcohol-associated neuronal oxidative stress and cellular injury

Alcohol Use Disorder (AUD) is a persistent condition linked to neuroinflammation, neuronal oxidative stress, and neurodegenerative processes. While the inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) has demonstrated effectiveness in reducing liver inflammation associated with alcohol, its impact on the brain remains largely unexplored. This study aimed to assess the effects of alirocumab, a monoclonal antibody targeting PCSK9 to lower systemic low-density lipoprotein cholesterol (LDL-C), on central nervous system (CNS) pathology in a rat model of chronic alcohol exposure. Alirocumab (50 mg/kg) or vehicle was administered weekly for six weeks in 32 male rats subjected to a 35 % ethanol liquid diet or a control liquid diet (n = 8 per group). The study evaluated PCSK9 expression, LDL receptor (LDLR) expression, oxidative stress, and neuroinflammatory markers in brain tissues. Chronic ethanol exposure increased PCSK9 expression in the brain, while alirocumab treatment significantly upregulated neuronal LDLR and reduced oxidative stress in neurons and brain vasculature (3-NT, p22phox). Alirocumab also mitigated ethanol-induced microglia recruitment in the cortex and hippocampus (Iba1). Additionally, alirocumab decreased the expression of pro-inflammatory cytokines and chemokines (TNF, CCL2, CXCL3) in whole brain tissue and attenuated the upregulation of adhesion molecules in brain vasculature (ICAM1, VCAM1, eSelectin). This study presents novel evidence that alirocumab diminishes oxidative stress and modifies neuroimmune interactions in the brain elicited by chronic ethanol exposure. Further investigation is needed to elucidate the mechanisms by which PCSK9 signaling influences the brain in the context of chronic ethanol exposure.

Development of orphan drugs for rare diseases

Most rare diseases (orphan diseases) still lack approved treatment options despite major advances in research providing the necessary tools to understand their molecular basis and legislation providing regulatory and economic incentives to expedite the development of specific therapies. Addressing this translational gap is a multifaceted challenge, a key aspect of which is the selection of an optimal therapeutic modality to translate advances in rare disease knowledge to potential medicines known as orphan drugs. There are several strategies for developing orphan drugs for rare genetic disorders, including protein replacement therapies, small-molecule therapies (e.g., substrate reduction, chemical chaperone, cofactor, expression modification, and read-through therapies), monoclonal antibodies, antisense oligonucleotides, small interfering RNA or exon skipping therapies, gene replacement and direct genome-editing therapies, mRNA therapy, cell therapy, and drug repurposing. Each strategy has its own strengths and limitations in orphan drug development. Furthermore, numerous hurdles are present in clinical trials of rare genetic diseases because of difficulty with patient recruitment, unknown molecular physiology, the natural history of the disease, ethical concerns regarding pediatric patients, and regulatory challenges. To address these barriers, the rare genetic diseases community, including academic institutions, industry, patient advocacy groups, foundations, payers, and government regulatory and research organizations, must become engaged in discussions about these issues.

Safety profile of proprotein convertase subtilisin/kexin type 9 inhibitors alirocumab and evolocumab: an updated meta-analysis and meta-regression

BACKGROUND

The use of alirocumab and evolocumab is generally safe and well-tolerated. However, concerns remain about their long-term safety, especially with regard to new-onset or worsening diabetes mellitus (DM). We aim to assess the safety profile of alirocumab and evolocumab compared to comparator.

METHODS

Studies were retrieved comparing the safety of PCSK9i vs. comparator (placebo or statin with or without ezetimibe). The primary outcome was adverse events leading to death. Secondary outcomes included serious adverse events, new onset diabetes mellitus (DM), worsening of DM, neurocognitive dysfunction, creatine kinase (CK) elevation, elevation of liver enzymes and local injection site reaction. Factors associated with the treatment effect were determined by meta-regression analysis. Subgroup analyses were done to explore potential treatment effect differences based on PCSK9i type and treatment duration.

RESULTS

We identified 56 studies with 85,123 adults (29.14% females). PCSK9i was not associated with adverse events that lead to death (OR 0.94, 95% CI 0.84 to 1.04, p = 0.22). Between the two PCSK9i, alirocumab decreased adverse events leading to death (OR 0.79, 95% CI, 0.67 to 0.94, p = 0.008). PCSK9i was associated with less serious events compared to the comparator (OR 0.93, 95% CI 0.89 to 0.98, p < 0.001). This reduction was driven mainly by alirocumab (OR 0.89, 95% CI, 0.85 to 0.93, p < 0.001). Evolocumab worsened DM (OR 2.3, 95% CI 1.26 to 4.2, p = 0.041). Subgroup analysis showed worsening of DM in the first 24 weeks of treatment with odds being highest in the first 12 weeks of treatment (<12 weeks: OR 3.82, 95% CI 1.13 to 12.99, p = 0.03; 12-24 weeks OR 2.12, 95% CI 1.20 to 3.73, p = 0.01. On the other hand, therapy >24 weeks reduced the odds of worsening DM (OR 0.89, 95% CI 0.79 to 0.99, p = 0.04). PCSK9i did not increase cognitive dysfunction, (OR 1.02, 95% CI 0.88 to 1.18, p = 0.76), or cause elevations in liver enzyme (OR 0.91, 95% CI 0.81 to 1.03, p = 0.14), or CK (OR 0.82, 95% CI 0.65 to 1.04, p = 0.10). However, PCSK9i was associated with local injection site reaction (OR 1.54, 95% CI 1.37 to 1.73, p < 0.01).

CONCLUSION

Alirocumab decreased adverse events leading to death. Alirocumab and Evolocumab both decreased serious adverse events. PCSK9i did not increase new onset DM however evolocumab worsened DM in the first 24 weeks of treatment. PCSK9i did not increase neurologic dysfunction, and did not elevate liver enzymes and CK, however it was associated with local injection site reaction.

Development of a PCSK9-targeted nanoparticle vaccine to effectively decrease the hypercholesterolemia

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the low-density lipoprotein receptor (LDLR) and mediates its internalization and degradation, resulting in an increase in LDL cholesterol levels. Recently, PCSK9 emerged as a therapeutic target for hypercholesterolemia and atherosclerosis. In this study, we develop a PCSK9 nanoparticle (NP) vaccine by covalently conjugating the catalytic domain (aa 153-aa 454, D374Y) of PCSK9 to self-assembled 24-mer ferritin NPs. We demonstrate that the PCSK9 NP vaccine effectively induces interfering antibodies against PCSK9 and reduces serum lipids levels in both a high-fat diet-induced hypercholesterolemia model and an adeno-associated virus-hPCSK9D374Y-induced hypercholesterolemia model. Additionally, the vaccine significantly reduces plaque lesion areas in the aorta and macrophages infiltration in an atherosclerosis mouse model. Furthermore, we discover that the vaccine's efficacy relied on T follicular help cells and LDLR. Overall, these findings suggest that the PCSK9 NP vaccine holds promise as an effective treatment for hypercholesterolemia and atherosclerosis.

Molecular mechanisms, targets and clinical potential of berberine in regulating metabolism: a review focussing on databases and molecular docking studies

Background: Metabolic imbalance is the common basis of many diseases. As natural isoquinoline alkaloid, berberine (BBR) has shown great promise in regulating glucose and lipids metabolism and treating metabolic disorders. However, the related mechanism still lacks systematic research. Aim: To discuss the role of BBR in the whole body's systemic metabolic regulation and further explore its therapeutic potential and targets. Method: Based on animal and cell experiments, the mechanism of BBR regulating systemic metabolic processes is reviewed. Potential metabolism-related targets were summarized using Therapeutic Target Database (TTD), DrugBank, GeneCards, and cutting-edge literature. Molecular modeling was applied to explore BBR binding to the potential targets. Results: BBR regulates the whole-body metabolic response including digestive, circulatory, immune, endocrine, and motor systems through adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR), sirtuin (SIRT)1/forkhead box O (FOXO)1/sterol regulatory element-binding protein (SREBP)2, nuclear factor erythroid 2-related factor (Nrf) 2/heme oxygenase (HO)-1, and other signaling pathways. Through these reactions, BBR exerts hypoglycemic, lipid-regulating, anti-inflammatory, anti-oxidation, and immune regulation. Molecular docking results showed that BBR could regulate metabolism targeting FOXO3, Nrf2, NAD(P)H quinone oxidoreductase 1 (NQO1), glutathione peroxidase (Gpx) 4 and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA). Evaluating the target clinical effects, we found that BBR has the therapeutic potential of anti-aging, anti-cancer, relieving kidney disease, regulating the nervous system, and alleviating other chronic diseases. Conclusion: This review elucidates the interaction between potential targets and small molecular metabolites by exploring the mechanism of BBR regulating metabolism. That will help pharmacologists to identify new promising metabolites interacting with these targets.

Global trends and research hotspots of PCSK9 and cardiovascular disease: a bibliometric and visual analysis

Background

Cardiovascular disease (CVD) is a prevalent non-communicable disease globally and holds the position of being the primary cause of mortality worldwide. Consequently, considerable focus has been directed towards the prevention and management of CVD. PCSK9, a frequently targeted element in the treatment and prevention of CVD, can reduce cardiovascular risk by effectively lowering lipid levels even in the context of statin therapy. It also exhibits substantial potential in the diagnosis and treatment of familial hypercholesterolemia from genetic aspects. This bibliometric study aims to analyze and visualize the global trends and emerging hotspots of PCSK9 and CVD researches and provide researchers with new perspectives in further studies.

Methods

The data was obtained from the Web of Science Core Collection database. A total of 2,474 publications related to PCSK9 and CVD published between January 2006 and July 2023 were included. The VOSviewer was used to analyze most-cited references, co-authorship, co-citation, co-occurrence and generate a collaborative network map of authors, countries, and institutions. CiteSpace was used to analyze author and institution centroids, keyword bursts, and timeline graphs.

Result

A total of 2,474 articles related to CVD and PCSK9 were included. The number of articles and citations show an increasing trend from year to year. Publications were mainly from the United States. The most active institution was Amgen Inc. Watts, Gerald F. was the most prolific author. Atherosclerosis was the most published journal. Literature co-citation and keyword co-occurrence revealed that early studies focused on the lipid-lowering effects of PCSK9 inhibitors in the context of statins therapy, long-term efficacy, adverse effects, LDLR, diagnosis and treatment of familial hypercholesterolemia. In recent years, myocardial ischemic protection, CRISPR-based editing, and new therapeutic strategies for arteriosclerotic cardiovascular disease have gotten wide attention. The protein convertase, inflammation, beta-polyacetate, and inclisiran may be the important future research directions.

Conclusion

This study analyses the current status and global trends in the CVD and PCSK9 studies comprehensively, which may provide researchers and policymakers with new and comprehensive perspectives on in this field of research.

Targeting PCSK9 as a key player in lipid metabolism: exploiting the therapeutic and biosensing potential of aptamers

The degradation of low-density lipoprotein receptor (LDLR) is induced by proprotein convertase subtilisin/kexin type 9 (PCSK9), resulting in elevated plasma concentrations of LDL cholesterol. Therefore, inhibiting the interactions between PCSK9 and LDLR is a desirable therapeutic goal for managing hypercholesterolemia. Aptamers, which are RNA or single-stranded DNA sequences, can recognize their targets based on their secondary structure. Aptamers exhibit high selectivity and affinity for binding to target molecules. The systematic evolution of ligands by exponential enrichment (SELEX), a combination of biological approaches, is used to screen most aptamers in vitro. Due to their unique advantages, aptamers have garnered significant interest since their discovery and have found extensive applications in various fields. Aptamers have been increasingly utilized in the development of biosensors for sensitive detection of pathogens, analytes, toxins, drug residues, and malignant cells. Furthermore, similar to monoclonal antibodies, aptamers can serve as therapeutic tools. Unlike certain protein therapeutics, aptamers do not elicit antibody responses, and their modified sugars at the 2'-positions generally prevent toll-like receptor-mediated innate immune responses. The focus of this review is on aptamer-based targeting of PCSK9 and the application of aptamers both as biosensors and therapeutic agents.

Association of statin use with osteoporosis risk: a drug-targeted Mendelian randomization study

BACKGROUND

Hypercholesterolemia and the related inflammatory response promote the development of osteoporosis, but whether targeted interventions are protective against this bone metabolic disease remains unknown. The aim of this study was to investigate the association between the use of statins (one well-recognized cholesterol-lowering drug with anti-inflammatory properties) and the risk of osteoporosis using a drug-targeted Mendelian randomization (MR) approach.

METHODS

Instrumental variables predicting three cholesterol-lowering target genes (including HGMCR) and the cholesterol effectors mediated by these genes (i.e., total cholesterol, LDL cholesterol, and non-HDL cholesterol) were extracted from expression quantitative trait loci and genome-wide association studies. Inverse variance-weighted (IVW), summary data-based MR (SMR), multivariate MR, and colocalization analysis were used to determine the association of the interventions represented by these instrumental variables with heel bone mineral density (one diagnostic indicator of osteoporosis).

RESULTS

The IVW reported that increased levels of HGMCR-mediated total cholesterol, LDL cholesterol, and non-HDL cholesterol were associated with the decreased level of heel bone mineral density (P = 4.086e-10, P = 1.487e-09, P = 1.967e-09). The colocalization analysis supported the relationship between HGMCR-mediated non-HDL cholesterol and heel bone mineral density. The SMR reported that higher expression of HGMCR was associated with the decreased level of this osteoporosis indicator (P = 0.036). The multivariate MR further confirmed the role of HGMCR in the correlation between cholesterol traits and heel bone mineral density, and also reported that estrogen played a mediating role in the above correlations.

CONCLUSION

These evidence supported a protective effect of HMGCR-mediated non-HDL cholesterol reduction or statin use against osteoporosis.

The current perspective and opportunities of small nucleic acid-based therapeutics

Compared to traditional small molecule and antibody drugs, RNA-based drugs offer a simple design, short research and development cycles, high specificity, broad treatment fields, and long-term efficacy. As a result, RNA-based drugs are extensively used to treat genetic diseases, tumors, viral infections, and other illnesses, suggesting that they have the potential to become the third-largest drug class after small molecule and antibody drugs. Currently, more than 10 small nucleic acid drugs have gained regulatory approval. The commercialization successes of small nucleic acid drugs will stimulate the development of RNA-based drugs. Small nucleic acid drugs primarily target liver diseases, metabolic diseases, genetic diseases, and tumors, and there is also significant potential for expanding indications in the future. This review provides a brief overview of the advantages and development of small nucleic acid-based therapeutics and shows a focus on platform technologies such as chemical modifications and delivery systems that have enabled the clinical translation of small nucleic acid-based therapeutics. Additionally, we summarize the latest clinical progress in small nucleic acid-based therapeutics for the treatment of various diseases, including rare diseases, liver diseases, metabolic diseases, and tumors. Finally, we highlight the future prospects for this promising treatment approach.

Potential use of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition and prevention method in viral infection

Cellular lipid membranes serve as the primary barrier preventing viral infection of the host cell and provide viruses with a critical initial point of contact. Occasionally, viruses can utilize lipids as viral receptors. Viruses depend significantly on lipid rafts for infection at virtually every stage of their life cycle. The pivotal role that proprotein convertase subtilisin/kexin Type 9 (PCSK9) plays in cholesterol homeostasis and atherosclerosis, primarily by post-transcriptionally regulating hepatic low-density lipoprotein receptor (LDLR) and promoting its lysosomal degradation, has garnered increasing interest. Conversely, using therapeutic, fully humanized antibodies to block PCSK9 leads to a significant reduction in high LDL cholesterol (LDL-C) levels. The Food and Drug Administration (FDA) has approved PCSK9 inhibitors, including inclisiran (Leqvio®), alirocumab (Praluent), and evolocumab (Repatha). At present, active immunization strategies targeting PCSK9 present a compelling substitute for passive immunization through the administration of antibodies. In addition to the current inquiry into the potential therapeutic application of PCSK9 inhibition in human immunodeficiency virus (HIV)-infected patients for hyperlipidemia associated with HIV and antiretroviral therapy (ART), preclinical research suggests that PCSK9 may also play a role in inhibiting hepatitis C virus (HCV) replication. Furthermore, PCSK9 inhibition has been suggested to protect against dengue virus (DENV) potentially and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viruses. Recent evidence regarding the impact of PCSK9 on a variety of viral infections, including HCV, HIV, DENV, and SARS-CoV-2, is examined in this article. As a result, PCSK9 inhibitors and vaccines may serve as viable host therapies for viral infections, as our research indicates that PCSK9 is significantly involved in the pathogenesis of viral infections.

Dyslipidemia, lipid-lowering agents and neuroendocrine neoplasms: new horizons

PURPOSE

Neuroendocrine neoplasms (NENs) are a heterogeneous group of malignancies originating from cells with a neuroendocrine phenotype. The complex relationship between lipid metabolism and cancer is gaining interest and a potential anti-cancer effect of lipid lowering agents is being considered. This review aims to discuss the current understanding and treatment of dyslipidaemia in NENs, focusing on the role of lipid lowering agents, including new therapeutic approaches, and future perspectives as possible tool in cancer prevention and tumor-growth control.

METHODS

We performed an electronic-based search using PubMed updated until December 2023, summarizing the available evidence both in basic and clinical research about lipid lowering agents in NENs.

RESULTS

Dyslipidemia is an important aspect to be considered in NENs management, although randomized studies specifically addressing this topic are lacking, unlike other cancer types. Available data mainly regard statins, and in vitro studies have demonstrated direct antitumor effects, including antiproliferative effects in some cancers, supporting possible pleiotropic effects also in NENs, but data remain conflicting. Ezetimibe, omega 3-fatty acids, fibrates and inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) may enhance the regulation of lipid homeostasis, as demonstrated in other cancers.

CONCLUSIONS

Targeting dyslipidemia in NENs should be part of the multidisciplinary management and an integrated approach may be the best option for both metabolic and tumor control. Whether lipid lowering agents may directly contribute to tumor control remains to be confirmed with specific studies, focusing on association with other metabolic risk, disease stage and primary site.

Role of PCSK9 inhibition during the inflammatory stage of SARS-COV-2: an updated review

The potential role of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition in the management of COVID-19 and other medical conditions has emerged as an intriguing area of research. PCSK9 is primarily known for its impact on cholesterol metabolism, but recent studies have unveiled its involvement in various physiological processes, including inflammation, immune regulation, and thrombosis. In this abstract, the authors review the rationale and potential implications of PCSK9 inhibition during the inflammatory stage of SARS-CoV-2 infection. Severe cases of COVID-19 are characterized by an uncontrolled inflammatory response, often referred to as the cytokine storm, which can lead to widespread tissue damage and organ failure. Preclinical studies suggest that PCSK9 inhibition could dampen this inflammatory cascade by reducing the production of pro-inflammatory cytokines. Additionally, PCSK9 inhibition may protect against acute respiratory distress syndrome (ARDS) through its effects on lung injury and inflammation. COVID-19 has been linked to an increased risk of cardiovascular complications, especially in patients with pre-existing cardiovascular conditions or dyslipidemia. PCSK9 inhibitors are known for their ability to lower low-density lipoprotein (LDL) cholesterol levels by enhancing the recycling of LDL receptors in the liver. By reducing LDL cholesterol, PCSK9 inhibition might protect blood vessels from further damage and lower the risk of atherosclerotic plaque formation. Moreover, PCSK9 inhibitors have shown potential antithrombotic effects in preclinical studies, making them a potential avenue to mitigate the increased risk of coagulation disorders and thrombotic events observed in COVID-19. While the potential implications of PCSK9 inhibition are promising, safety considerations and possible risks need careful evaluation. Hypocholesterolemia, drug interactions, and long-term safety are some of the key concerns that should be addressed. Clinical trials are needed to establish the efficacy and safety of PCSK9 inhibitors in COVID-19 patients and to determine the optimal timing and dosing for treatment. Future research opportunities encompass investigating the immune response, evaluating long-term safety, exploring combination therapy possibilities, and advancing personalized medicine approaches. Collaborative efforts from researchers, clinicians, and policymakers are essential to fully harness the therapeutic potential of PCSK9 inhibition and translate these findings into meaningful clinical outcomes.

The Application of Peptide Nucleic Acids (PNA) in the Inhibition of Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) Gene Expression in a Cell-Free Transcription/Translation System

Proprotein convertase subtilisin/kexin 9 (PCSK9) is a protein that plays a key role in the metabolism of low-density lipoprotein (LDL) cholesterol. The gain-of-function mutations of the PCSK9 gene lead to a reduced number of surface LDL receptors by binding to them, eventually leading to endosomal degradation. This, in turn, is the culprit of hypercholesterolemia, resulting in accelerated atherogenesis. The modern treatment for hypercholesterolemia encompasses the use of biological drugs against PCSK9, like monoclonal antibodies and gene expression modulators such as inclisiran-a short, interfering RNA (siRNA). Peptide nucleic acid (PNA) is a synthetic analog of nucleic acid that possesses a synthetic peptide skeleton instead of a phosphate-sugar one. This different structure determines the unique properties of PNA (e.g., neutral charge, enzymatic resistance, and an enormously high affinity with complementary DNA and RNA). Therefore, it might be possible to use PNA against PCSK9 in the treatment of hypercholesterolemia. We sought to explore the impact of three selected PNA oligomers on PCSK9 gene expression. Using a cell-free transcription/translation system, we showed that one of the tested PNA strands was able to reduce the PCSK9 gene expression down to 74%, 64%, and 68%, as measured by RT-real-time PCR, Western blot, and HPLC, respectively. This preliminary study shows the high applicability of a cell-free enzymatic environment as an efficient tool in the initial evaluation of biologically active PNA molecules in the field of hypercholesterolemia research. This cell-free approach allows for the omission of the hurdles associated with transmembrane PNA transportation at the early stage of PNA selection.

Targeting proprotein convertase subtilisin/kexin type 9 (PCSK9): from bench to bedside

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has evolved as a pivotal enzyme in lipid metabolism and a revolutionary therapeutic target for hypercholesterolemia and its related cardiovascular diseases (CVD). This comprehensive review delineates the intricate roles and wide-ranging implications of PCSK9, extending beyond CVD to emphasize its significance in diverse physiological and pathological states, including liver diseases, infectious diseases, autoimmune disorders, and notably, cancer. Our exploration offers insights into the interaction between PCSK9 and low-density lipoprotein receptors (LDLRs), elucidating its substantial impact on cholesterol homeostasis and cardiovascular health. It also details the evolution of PCSK9-targeted therapies, translating foundational bench discoveries into bedside applications for optimized patient care. The advent and clinical approval of innovative PCSK9 inhibitory therapies (PCSK9-iTs), including three monoclonal antibodies (Evolocumab, Alirocumab, and Tafolecimab) and one small interfering RNA (siRNA, Inclisiran), have marked a significant breakthrough in cardiovascular medicine. These therapies have demonstrated unparalleled efficacy in mitigating hypercholesterolemia, reducing cardiovascular risks, and have showcased profound value in clinical applications, offering novel therapeutic avenues and a promising future in personalized medicine for cardiovascular disorders. Furthermore, emerging research, inclusive of our findings, unveils PCSK9's potential role as a pivotal indicator for cancer prognosis and its prospective application as a transformative target for cancer treatment. This review also highlights PCSK9's aberrant expression in various cancer forms, its association with cancer prognosis, and its crucial roles in carcinogenesis and cancer immunity. In conclusion, this synthesized review integrates existing knowledge and novel insights on PCSK9, providing a holistic perspective on its transformative impact in reshaping therapeutic paradigms across various disorders. It emphasizes the clinical value and effect of PCSK9-iT, underscoring its potential in advancing the landscape of biomedical research and its capabilities in heralding new eras in personalized medicine.

Bidirectional causal relationship between hypercholesterolemia and ischemic heart disease: a Mendelian randomization study

Background

Ischemic Heart Disease (IHD) is a leading cause of morbidity and mortality worldwide. Hypercholesterolaemia, a metabolic syndrome distinguished by elevated cholesterol levels, is positively correlated with IHD, yet the precise causal relationship between these two health conditions remains to be clearly defined.

Methods

We conducted a two-sample MR analysis using genetic variants associated with hypercholesterolemia and IHD. Various statistical techniques including MR-Egger, Weighted Median, Inverse Variance Weighted (IVW), Simple Mode, and Weighted Mode were employed. We also performed sensitivity analyses to assess pleiotropy, heterogeneity, and influence of individual SNPs. Furthermore, genetic co-localization analysis was performed to identify shared genes between hypercholesterolemia and IHD.

Results

Our MR study illuminated a bidirectional causal relationship between hypercholesterolaemia and ischaemic heart disease. Utilising the IVW with multiplicative random effects, upon considering IHD as the outcome, we identified an OR of 2.27 (95% CI: 1.91-2.70, p = 1.68 × 10-20). Conversely, when hypercholesterolaemia was viewed as the outcome, the OR detected was 1.80 (95% CI: 1.58-2.05, p = 2.79 × 10-19). These findings remained consistent across various MR methods and sensitivity analyses. Additionally, our research pinpointed four co-localised genes CELSR2, PCSK9, LPA, and APOE as integral candidates implicated in the pathogenesis of both conditions, thereby suggesting shared common genetic causal variants and offering potential targets for innovative therapeutic strategies.

Conclusion

bidirectional MR studies reveal genetic evidence of a potential causal link between hypercholesterolaemia and IHD. Notably, these findings also lend credence to the less traditional hypothesis that IHD may instigate hypercholesterolaemia episodes. Moreover, co-localisation analyses intimate the presence of shared genetic causal variants, paving the way for the development of new therapeutic strategies.

Cholesterol Metabolism in Pancreatic Cancer

Pancreatic cancer's substantial impact on cancer-related mortality, responsible for 8% of cancer deaths and ranking fourth in the US, persists despite advancements, with a five-year relative survival rate of only 11%. Forecasts predict a 70% surge in new cases and a 72% increase in global pancreatic cancer-related deaths by 2040. This review explores the intrinsic metabolic reprogramming of pancreatic cancer, focusing on the mevalonate pathway, including cholesterol biosynthesis, transportation, targeting strategies, and clinical studies. The mevalonate pathway, central to cellular metabolism, significantly shapes pancreatic cancer progression. Acetyl coenzyme A (Acetyl-CoA) serves a dual role in fatty acid and cholesterol biosynthesis, fueling acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) development. Enzymes, including acetoacetyl-CoA thiolase, 3-hydroxy-3methylglutaryl-CoA (HMG-CoA) synthase, and HMG-CoA reductase, are key enzymes in pancreatic cancer. Inhibiting HMG-CoA reductase, e.g., by using statins, shows promise in delaying PanIN progression and impeding pancreatic cancer. Dysregulation of cholesterol modification, uptake, and transport significantly impacts tumor progression, with Sterol O-acyltransferase 1 (SOAT1) driving cholesterol ester (CE) accumulation and disrupted low-density lipoprotein receptor (LDLR) expression contributing to cancer recurrence. Apolipoprotein E (ApoE) expression in tumor stroma influences immune suppression. Clinical trials targeting cholesterol metabolism, including statins and SOAT1 inhibitors, exhibit potential anti-tumor effects, and combination therapies enhance efficacy. This review provides insights into cholesterol metabolism's convergence with pancreatic cancer, shedding light on therapeutic avenues and ongoing clinical investigations.

Beyond statins: New pharmacological targets to decrease LDL-cholesterol and cardiovascular events

The pharmacological treatment of dyslipidemia, a major modifiable risk factor for developing atherosclerotic cardiovascular disease (ASCVD), remains a debated and controversial issue, not only in terms of the most appropriate therapeutic range for lipid levels, but also with regard to the optimal strategy and sequence approach (stepwise vs upstream therapy). Current treatment guidelines for the management of dyslipidemia focus on the intensity of low-density lipoprotein cholesterol (LDL-C) reduction, stratified according to risk for developing ASCVD. Beyond statins and ezetimibe, different medications targeting LDL-C have been recently approved by regulatory agencies with potential innovative mechanisms of action, including proprotein convertase subtilisin/kexin type 9 modulators (monoclonal antibodies such as evolocumab and alirocumab; small interfering RNA molecules such as inclisiran), ATP-citrate lyase inhibitors (bempedoic acid), angiopoietin-like 3 inhibitors (evinacumab), and microsomal triglyceride transfer protein inhibitors (lomitapide). An understanding of their pharmacological aspects, benefit-risk profile, including impact on hard cardiovascular endpoints beyond LDL-C reduction, and potential advantages from the patient perspective (e.g., adherence) - the focus of this evidence-based review - is crucial for practitioners across medical specialties to minimize therapeutic inertia and support clinical practice.

The Anti-Thrombotic Effects of PCSK9 Inhibitors

Atherosclerosis is the primary process that underlies cardiovascular disease. The connection between LDL cholesterol and the formation of atherosclerotic plaques is established by solid evidence. PCSK9 inhibitors have proven to be a valuable and practical resource for lowering the LDL cholesterol of many patients in recent years. Their inhibitory effect on atherosclerosis progression seems to be driven not just by lipid metabolism modification but also by LDL-independent mechanisms. We review the effect of PCSK9 inhibitors on various mechanisms involving platelet activation, inflammation, endothelial dysfunction, and the resultant clot formation. The main effectors of PCSK9 activation of platelets are CD36 receptors, lipoprotein(a), oxidised LDL particles, tissue factor, and factor VIII. Many more molecules are under investigation, and this area of research is growing rapidly.

Current Management and Future Perspectives in the Treatment of Lp(a) with a Focus on the Prevention of Cardiovascular Diseases

Lipoprotein(a) [Lp(a)] is a lipid molecule with atherogenic, inflammatory, thrombotic, and antifibrinolytic effects, whose concentrations are predominantly genetically determined. The association between Lp(a) and cardiovascular diseases (CVDs) has been well-established in numerous studies, and the ability to measure Lp(a) levels is widely available in the community. As such, there has been increasing interest in Lp(a) as a therapeutic target for the prevention of CVD. The impact of the currently available lipid-modifying agents on Lp(a) is modest and heterogeneous, except for the monoclonal antibody proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), which demonstrated a significant reduction in Lp(a) levels. However, the absolute reduction in Lp(a) to significantly decrease CVD outcomes has not been definitely established, and the magnitude of the effect of PCSK9i seems insufficient to directly reduce the Lp(a)-related CVD risk. Therefore, emerging therapies are being developed that specifically aim to lower Lp(a) levels and the risk of CVD, including RNA interference (RNAi) agents, which have the capacity for temporary and reversible downregulation of gene expression. This review article aims to summarize the effects of Lp(a) on CVD and to evaluate the available evidence on established and emerging therapies targeting Lp(a) levels, focusing on the potential reduction of CVD risk attributable to Lp(a) concentrations.

Prognostic Value of Non-HDL Cholesterol in COVID-19 Pneumonia

BACKGROUND

In addition to coronary artery disease, non-high-density lipoprotein(non-HDL-C) provides short and long-term predictive information for many chronic inflammatory diseases such as stroke, hemodialysis, post-renal transplant, non-alcoholic hepatosteatosis, and human immunodeficiency virus.

OBJECTIVES

This study examined the predictive value of non-HDL-C measured before SARS-CoV-2 for mortality in COVID-19 infection.

METHODS

This study retrospectively included 1435 patients diagnosed with COVID-19 and treated in the thoracic diseases ward in a single center between January 2020 and June 2022. All patients included in the study had clinical and radiological features and signs of COVID-19 pneumonia. The COVID-19 diagnosis of all patients was confirmed by a polymerase chain reaction studied from an oropharyngeal swab. Statistical significance was set at p < 0.05.

RESULTS

The study patients, including 1435 subjects, were divided into 712 patients in the non-surviving group and 723 in the surviving group. While there was no difference between the groups regarding gender, there was a statistically significant age difference. The non-surviving group was older. Age, lactate dehydrogenase(LDH), C reactive protein(CRP), triglycerides, D-dimer, and non-HDL-C were independent risk factors for mortality in regression analyses. In correlation analysis, age, CRP, and LDH were positively correlated with non-HDL-C. In the ROC analysis, sensitivity for non-HDL-C was 61.6%, and specificity was 89.2%.

CONCLUSION

We believe that the non-HDL-C level studied before COVID-19 infection can be used as a prognostic biomarker for the disease.

Inclisiran, Low-Density Lipoprotein Cholesterol and Lipoprotein (a)

Dyslipidemia treatment is of major importance in reducing the risk of atherosclerotic cardiovascular disease (ASCVD), which is still the most common cause of death worldwide. During the last decade, a novel lipid-lowering drug category has emerged, i.e., proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Apart from the two available anti-PCSK9 monoclonal antibodies (alirocumab and evolocumab), other nucleic acid-based therapies that inhibit or "silence" the expression of PCSK9 are being developed. Among them, inclisiran is the first-in-class small interfering RNA (siRNA) against PCSK9 that has been approved by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of hypercholesterolemia. Importantly, inclisiran therapy may improve low-density lipoprotein cholesterol (LDL-C) target achievement by offering a prolonged and significant LDL-C-lowering effect with the administration of only two doses per year. The present narrative review discusses the ORION/VICTORION clinical trial program that has been designed to investigate the impact of inclisiran on atherogenic lipoproteins and major adverse cardiac events in different patient populations. The results of the completed clinical trials are presented, focusing on the effects of inclisiran on LDL-C and lipoprotein (a) (Lp(a)) levels as well as on other lipid parameters such as apolipoprotein B and non-high-density lipoprotein cholesterol (non-HDL-C). Ongoing clinical trials with inclisiran are also discussed.

Untargeted Lipidomic Profiling Reveals Lysophosphatidylcholine and Ceramide as Atherosclerotic Risk Factors in apolipoprotein E Knockout Mice

Despite the availability and use of numerous cholesterol-lowering drugs, atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of mortality globally. Many researchers have focused their effort on identifying modified lipoproteins. However, lipid moieties such as lysophosphatidylcholine (LPC) and ceramide (CER) contribute to atherogenic events. LPC and CER both cause endothelial mitochondrial dysfunction, leading to fatty acid and triglyceride (TG) accumulation. In addition, they cause immune cells to differentiate into proinflammatory phenotypes. To uncover alternative therapeutic approaches other than cholesterol- and TG-lowering medications, we conducted untargeted lipidomic investigations to assess the alteration of lipid profiles in apolipoprotein E knockout (apoE^-/-) mouse model, with or without feeding a high-fat diet (HFD). Results indicated that, in addition to hypercholesterolemia and hyperlipidemia, LPC levels were two to four times higher in apoE^-/- mice compared to wild-type mice in C57BL/6 background, regardless of whether they were 8 or 16 weeks old. Sphingomyelin (SM) and CER were elevated three- to five-fold in apoE^-/- mice both at the basal level and after 16 weeks when compared to wild-type mice. After HFD treatment, the difference in CER levels elevated more than ten-fold. Considering the atherogenic properties of LPC and CER, they may also contribute to the early onset of atherosclerosis in apoE^-/- mice. In summary, the HFD-fed apoE^-/- mouse shows elevated LPC and CER contents and is a suitable model for developing LPC- and CER-lowering therapies.

Inclisiran—A Revolutionary Addition to a Cholesterol-Lowering Therapy

Hypercholesterolemia plays a crucial role in the development of atherosclerosis, but it remains an undertreated and underdiagnosed disease. Taking into consideration the high prevalence of lipid disorders, long duration of the asymptomatic course of the disease, life-threatening complications resulting from inaccurate therapy, and stringent treatment goals concerning LDL cholesterol level in the prevention of cardiovascular events, novel lipid-lowering therapies have been introduced in the last few years. In this article, a drug belonging to the group of small interfering RNA (siRNA) called inclisiran is described. It is a novel molecule that increases the number of LDL receptors (LDLRs) on the surface of hepatic cells by preventing the formation of proprotein convertase subtilisin/kexin type 9 (PCSK9) responsible for the degradation of LDLRs. With great potential for lowering plasma LDL cholesterol level, high liver specificity, comfortable dosing regimen, and good tolerance without significant adverse effects, it could play an important part in future hypolipemic therapies.

Interplay between microRNAs, Serum Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), and Lipid Parameters in Patients with Very High Lipoprotein(a) Treated with PCSK9 Inhibitors

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has an important function in the regulation of lipid metabolism. PCSK9 reduces hepatic low-density lipoprotein receptors, thereby increasing low-density lipoprotein cholesterol levels. However, its regulation remains to be elucidated, including post-transcriptional regulation by microRNAs (miRNAs). We aimed to explore the interplay between miRNAs, total serum PCSK9, and lipids during treatment with PCSK9 inhibitors. A total of 64 patients with stable coronary artery disease and very high lipoprotein(a) levels and 16 sex- and age-matched control subjects were enrolled. Patients received a PCSK9 inhibitor (evolocumab or alirocumab). Total serum PCSK9 levels were measured by immunoassay. RNA was isolated from plasma using magnetic beads, and expression of selected miRNAs was analyzed by quantitative PCR. Total serum PCSK9 levels were significantly higher in control subjects compared with patients. After 6 months of treatment with PCSK9 inhibitors, total serum PCSK9 levels increased significantly. The expression of miR-191-5p was significantly lower, and the expression of miR-224-5p and miR-483-5p was significantly higher in patients compared with control subjects. Using linear regression, the expression of miR-483-5p significantly predicted the serum PCSK9 level at baseline. After the 6-month period of therapy, the expression of miR-191-5p and miR-483-5p significantly increased. Our results support a role for miR-483-5p in regulating circulating PCSK9 in vivo. The difference in expression of miR-191-5p, miR-224-5p, and miR-337-3p between patients and control subjects suggests their possible role in the pathogenesis of coronary artery disease.

PCSK9 Inhibitors in Cancer Patients Treated with Immune-Checkpoint Inhibitors to Reduce Cardiovascular Events: New Frontiers in Cardioncology

Cancer patients treated with immune checkpoint inhibitors (ICIs) are exposed to a high risk of atherosclerosis and cardiometabolic diseases due to systemic inflammatory conditions and immune-related atheroma destabilization. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein involved in metabolism of low-density lipoprotein (LDL) cholesterol. PCSK9 blocking agents are clinically available and involve monoclonal antibodies, and SiRNA reduces LDL levels in high-risk patients and atherosclerotic cardiovascular disease events in multiple patient cohorts. Moreover, PCSK9 induces peripheral immune tolerance (inhibition of cancer cell- immune recognition), reduces cardiac mitochondrial metabolism, and enhances cancer cell survival. The present review summarizes the potential benefits of PCSK9 inhibition through selective blocking antibodies and siRNA in patients with cancer, especially in those treated with ICIs therapies, in order to reduce atherosclerotic cardiovascular events and potentially improve ICIs-related anticancer functions.

Proprotein Convertase Subtilisin/Kexin 9 as a Modifier of Lipid Metabolism in Atherosclerosis

Despite being the most common treatment strategy in the management of atherosclerosis and subsequent cardiovascular disease, classical statin therapy has certain disadvantages, including numerous side effects. In addition, a regimen with daily administration of the drug is hard to comply with. Thus, there is a need for modern and more efficient therapeutic strategies in CVD treatment. There is extensive evidence indicating that PCSK9 promotes atherogenesis through a variety of mechanisms. Thus, new treatment methods can be developed that prevent or alleviate atherosclerotic cardiovascular disease by targeting PCSK9. Comprehensive understanding of its atherogenic properties is a necessary precondition for the establishment of new therapeutic strategies. In this review, we will summarize the available data on the role of PCSK9 in the development and progression of atherosclerosis. In the last section, we will consider existing PCSK9 inhibitors.

Treatment with Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors (PCSK9i): Current Evidence for Expanding the Paradigm?

Background: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are low-density lipoprotein cholesterol (LDL-C)-lowering drugs that play a critical role in lipoprotein clearance and metabolism. PCSK9i are used in patients with familial hypercholesterolemia and for the secondary prevention of acute cardiovascular events in patients with atherosclerotic cardiovascular disease (CVD). Methods: We focused on the literature from 2015, the year of approval of the PCSK9 monoclonal antibodies, to the present on the use of PCSK9i not only in the lipid field but also by evaluating their effects on metabolic factors. Results: PCSK9 inhibits cholesterol efflux from macrophages and contributes to the formation of macrophage foam cells. PCSK9 has the ability to bind to Toll-like receptors, thus mediating the inflammatory response and binding to scavenger receptor B/cluster of differentiation 36. PCSK9i lower the entire spectrum of apolipoprotein B-100 containing lipoproteins (LDL, very LDLs, intermediate-density lipoproteins, and lipoprotein[a]) in high CVD-risk patients. Moreover, PCSK9 inhibitors are neutral on risk for new-onset diabetes mellitus and might have a beneficial impact on the development of nonalcoholic fatty liver disease by improving lipid and inflammatory biomarker profiles, steatosis biomarkers such as the triglyceride-glucose index, and hepatic steatosis index, although there are no comprehensive studies with long-term follow-up studies. Conclusion: The discovery of PCSK9i has opened a new era in therapeutic management in patients with hypercholesterolemia and high cardiovascular risk. Increasingly, there has been mounting scientific and clinical evidence supporting the safety and tolerability of PCSK9i.

Myocardial injury: where inflammation and autophagy meet

Autophagy is a highly conserved bulk degradation mechanism that degrades damaged organelles, aged proteins and intracellular contents to maintain the homeostasis of the intracellular microenvironment. Activation of autophagy can be observed during myocardial injury, during which inflammatory responses are strongly triggered. Autophagy can inhibit the inflammatory response and regulate the inflammatory microenvironment by removing invading pathogens and damaged mitochondria. In addition, autophagy may enhance the clearance of apoptotic and necrotic cells to promote the repair of damaged tissue. In this paper, we briefly review the role of autophagy in different cell types in the inflammatory microenvironment of myocardial injury and discuss the molecular mechanism of autophagy in regulating the inflammatory response in a series of myocardial injury conditions, including myocardial ischemia, ischemia/reperfusion injury and sepsis cardiomyopathy.

Small-interfering RNA targeting proprotein convertase subtilisin/kexin type 9 might promote fatty liver disease and hepatocellular carcinoma through upregulation of CD36

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein (LDL) receptor and fatty acid translocase CD36, inducing lysosomal degradation of these two receptors in the liver cells. Both monoclonal antibody (mAb) and small-interfering RNA (siRNA) targeting PCSK9 have been designed for treatment of familial hypercholesterolemia recently, with elevating LDL receptors on the liver cell surface and increasing LDL uptake as the main beneficial mechanism. However, given that the binding domains of PCSK9 for LDL receptor and CD36 are different, and PCSK9 mAb only attacks the domain for LDL receptor, CD36 expression remains partially controlled under PCSK9 mAb treatment. In contrast, PCSK9 siRNA brings on complete loss of PCSK9, resulting in overexpression of CD36. Based on the fact that CD36 is a key factor in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) and subsequent hepatocellular carcinoma (HCC), the risk of developing NAFLD and HCC on long-term use of PCSK9 siRNA is thus raised as a hypothesis. Additionally, because CD36 is also involved in the promotion of malignant diseases other than HCC, such as acute myeloid leukemia, gastric cancer, breast cancer, and colorectal cancer, the speculative danger of flourishing these malignancies by PCSK9 siRNA is discussed as well.

Immunity: Psoriasis comorbid with atherosclerosis

Psoriasis is an immune-mediated, persistent inflammatory disease with a genetic predisposition, and the involvement of multiple organs in psoriasis remains indicative of systemic disease. Atherosclerosis (AS) is a common complication of patients with severe or prolonged psoriasis. The specific pathogenesis of psoriasis is still unclear. Current studies suggest that psoriasis is a polygenic genetic disease with the interaction of multiple factors such as heredity and environment. Keratinocytes are proliferated through immune-mediated inflammatory pathway, which leads to cell activation, infiltration of dermis cells and release of inflammatory factors. Activation of inflammatory cells and pro-inflammatory factors play an important role in the progression of psoriasis and atherosclerosis. Studies have found that there is a close relationship between psoriasis and atherosclerosis, and systemic inflammation may be the common feature of psoriasis and AS. This paper attempts to explore the possibility of the relationship between psoriasis and atherosclerotic comorbidities from the aspects of potential epidemiology and immune mechanism, in order to provide some reference for the subsequent scientific research.