Proprotein Convertase Subtilisin Kexin Research Articles

PCSK9 inhibition protects mice from food allergy

The Proprotein Convertase Subtilisin Kexin of type 9 (PCSK9) has been identified in 2003 as the third gene involved in familial hypercholesterolemia. PCSK9 binds to the membrane low-density lipoprotein receptor (LDLR) and promotes its cellular internalization and lysosomal degradation. Beyond this canonical role, PCSK9 was recently described to be involved in several immune responses. However, to date, the contribution of PCSK9 in food allergy remains unknown. Here, we showed that Pcsk9 deficiency or pharmacological inhibition of circulating PCSK9 with a specific monoclonal antibody (m-Ab) protected mice against symptoms of gliadin-induced-food allergy, such as increased intestinal transit time and ear oedema. Furthermore, specific PCSK9 inhibition during the elicitation steps of allergic process was sufficient to ensure anti-allergic effects in mice. Interestingly, the protective effect of PCSK9 inhibition against food allergy symptoms was independent of the LDLR as PCSK9 inhibitors remained effective in Ldlr deficient mice. In vitro, we showed that recombinant gain of function PCSK9 (PCSK9 D374Y) increased the percentage of mature bone marrow derived dendritic cells (BMDCs), promoted naïve T cell proliferation and potentiated the gliadin induced basophils degranulation. Altogether, our data demonstrate that PCSK9 inhibition is protective against gliadin induced food allergy in a LDLR-independent manner.

Role of Proprotein Convertase Subtilisin Kexin Type 9 Inhibitor Therapy in treatment of Patients with Polycystic Ovary Syndrome: A systemic Review of Metabolic and Cardiovascular Outcomes

Polycystic Ovary Syndrome (PCOS) is a common endocrine condition that affects both obese and nonobese women of reproductive age group. Its clinical presentation is dysmenorrhea, hirsutism, acne, metabolic complications, infertility, and polycystic ovaries. The study is aimed to assess the efficacy of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitors to lower dyslipidemia in women with PCOS to prevent long term cardio-metabolic complications. PCSK 9 Inhibitors ( Alirocumab, Evolocumab, and Inclisiran) bind to LDL receptors in liver and lower LDLC levels, preventing long term adverse side effects. This review aims at showing that these drugs can be effective when prescribed to women with PCOS earlyon to prevent some serious cardiovascular and metabolic complications in the long run. In terms of medical therapy, most physicians prescribe Metformin and Statins as first line agents to control risk factors. But much of the research supported the use of PCSK 9 Inhibitors early in the disease process or as an add-on to statins for controlling the lipid profile. When compared to Statins, the control rates of PCSK 9 Inhibitors were equal or superior and they showed additive effect when given along with other lipid lowering agents. Studies showed these drugs have only minor side effects and have good tolerability profile. They do not have severe side effects as compared to statins or fibrates.

PCSK9 dysregulates cholesterol homeostasis and triglyceride metabolism in olanzapine-induced hepatic steatosis via both receptor-dependent and receptor-independent pathways.

Schizophrenia, affecting approximately 1% of the global population, is often treated with olanzapine. Despite its efficacy, olanzapine's prolonged use has been associated with an increased risk of cardiovascular diseases and nonalcoholic fatty liver disease (NAFLD); however, the underlying mechanism remains unclear. Proprotein convertase subtilisin kexin type 9 (PCSK9) plays a crucial role in lipid metabolism and is involved in NAFLD pathogenesis via an unknown mechanism. This study aims to investigate the role of PCSK9 in olanzapine-induced NAFLD. C57BL/6J mice and HepG2 and AML12 cell lines were treated with varying concentrations of olanzapine to examine the effects of olanzapine on PCSK9 and lipid metabolism. PCSK9 levels were manipulated using recombinant proteins, plasmids, and small interfering RNAs invitro, and the effects on hepatic lipid accumulation and gene expression related to lipid metabolism were assessed. Olanzapine treatment significantly increased PCSK9 levels in both animal and cell line models, correlating with elevated lipid accumulation. PCSK9 manipulation demonstrated its central role in mediating hepatic steatosis through both receptor-dependent pathways (impacting NPC1L1) and receptor-independent pathways (affecting lipid synthesis, uptake, and cholesterol biosynthesis). Interestingly, upregulation of SREBP-1c, rather than SREBP-2, was identified as a key driver of PCSK9 increase in olanzapine-induced NAFLD. Our findings establish PCSK9 as a pivotal factor in olanzapine-induced NAFLD, influencing both receptor-related and metabolic pathways. This highlights PCSK9 inhibitors as potential therapeutic agents for managing NAFLD in schizophrenia patients treated with olanzapine.

Safety and Efficacy of PCSK9 Inhibitors in Patients with Acute Coronary Syndrome Who Underwent Coronary Artery Bypass Grafts: A Comparative Retrospective Analysis

Background. The in-hospital reduction in low-density lipoprotein cholesterol (LDL-C) levels following acute coronary syndrome (ACS) is recommended in the current clinical guidelines. However, the efficacy of proprotein convertase subtilisin–kexin type 9 (PCSK9) inhibitors in those patients undergoing coronary artery bypass graft (CABG) has never been demonstrated. Methods. From January 2022 to July 2023, we retrospectively analyzed 74 ACS patients characterized by higher LDL-C levels than guideline targets and who underwent coronary bypass surgery. In the first period (January 2022–January 2023), the patients increased their statin dosage and/or added Ezetimibe (Group STEZE, 43 patients). At a later time (February 2023–July 2023), the patients received not only statins and Ezetimibe but also Evolocumab 140 mg every 2 weeks starting as early as possible (Group STEVO, 31 patients). After one and three months post-discharge, the patients underwent clinical and laboratory controls with an evaluation of the efficacy lipid measurements and every adverse event. Results. The two groups did not differ in terms of preoperative risk factors and Euroscore II (STEVO: 2.14 ± 0.75 vs. STEZE: 2.05 ± 0.6, p = 0.29). Also, there was no difference between the groups in terms of ACS (ST-, Instable angina, or NSTE) and time of symptoms onset regarding total cholesterol, LDL-C, and HDL-C trends from the preprocedural period to 3-month follow-up, but there was a more significant reduction in LDL-C and total cholesterol in the STEVO group (p = 0.01 and p = 0.04, respectively) and no difference in HDL-C rise (p = 0.12). No deaths were reported. In three STEZE group patients, angina recurrence posed the need for percutaneous re-revascularization. No STEVO patients developed significant adverse events. The statistical difference in these serious events, 7% in STEZE vs. 0% in STEVO, was not significant (p = 0.26). Conclusions. Evolocumab initiated “as soon as possible” in ACS patients submitted to CABG with high-intensity statin therapy and Ezetimibe was well tolerated and resulted in a substantial and significant reduction in LDL-C levels at discharge, 1 month, and 3 months. This result is associated with a reduction but without a statistical difference between groups.

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.

The use of statins and inhibitors of proprotein convertase subtilisin-kexin type 9 (PCSK 9) in patients with dyslipidemia

Scientific relevance. According to the WHO data, cardiovascular diseases rank first as the cause of human death. In 2022, 18,601,923 people died from cardiovascular diseases, which amounted to 33 % of the total mortality in the world. Malignant neoplasms rank second with 9,958,133 deaths, representing 17.6 % of total mortality. Among cardiovascular diseases, ischemic heart disease (IHD), the pathogenesis of which is associated with impaired cholesterol and lipoprotein metabolism, is leading. The use of statin drugs is recommended as a first-line lipid-lowering therapy. As an alternative to HMG-CoA reductase inhibitors (statins), proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9) were discovered in 2003, however, they are less popular due to insuf ficient data on these drugs and their costliness. Purpose of the work: to study the safety of using proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in patients with dyslipidemia and compare the advantages and disadvantages in relation to the ef fects of HMG-CoA reductase (statins). Discussion: The analysis of literature data has shown that the most frequent manifestations of intolerance to statins are muscle symptoms. The main mechanisms of statin-associated complications are mediated by inhibition of HMG-CoA reductase, as well as by the effect of drugs on cellular and subcellular processes, skeletal muscles and genetic features of patients. PCSK9 inhibitors have a fundamentally different mechanism of action — they bind and inactivate PCSK9, which leads to a decrease of low-density lipoprotein cholesterol in the blood level. A small number of undesirable reactions have been identified for drugs of this group, the most important of which is immunogenicity. However, even if patients have antibodies to PCSK9 inhibitor, the efficacy of the drug in reducing the level of low-density lipoproteins remains high.Conclusion. In medical studies, PCSK9 inhibitors have been shown to perform better compared to HMG-CoA reductase inhibitors; meanwhile, patients continue to use statins as lipid-lowering medications.

The Causal Relationship between PCSK9 Inhibitors and Malignant Tumors: A Mendelian Randomization Study Based on Drug Targeting.

Objective: This study explores the potential causal association between proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors and tumor development using Mendelian randomization (MR) based on drug targets. Methods: Instrumental variables within ±100 kb of the PCSK9 gene locus, impacting low-density lipoprotein cholesterol (LDL-C), were utilized for MR analysis. Coronary heart disease (CHD) served as a positive control to validate the causal relationship between PCSK9 inhibitors and various cancers. We employed reverse MR to address the reverse causation concerns. Data from positive controls and tumors were sourced from OpenGWAS. Results: MR analysis suggested a negative causal relationship between PCSK9 inhibitors and both breast and lung cancers (95%CIBreast cancer 0.81~0.99, p = 2.25 × 10-2; 95%CILung cancer 0.65~0.94, p = 2.55 × 10-3). In contrast, a positive causal link was observed with gastric, hepatic, and oral pharyngeal cancers and cervical intraepithelial neoplasia (95%CIGastric cancer 1.14~1.75, p = 1.88 × 10-2; 95%CIHepatic cancer 1.46~2.53, p = 1.16 × 10-2; 95%CIOral cavity and pharyngeal cancer 4.49~6.33, p = 3.36 × 10-4; 95%CICarcinoma in situ of cervix uteri 4.56~7.12, p = 6.91 × 10-3), without heterogeneity or pleiotropy (p > 0.05). Sensitivity analyses confirmed these findings. The results of MR of drug targets suggested no causal relationship between PCSK9 inhibitors and bladder cancer, thyroid cancer, pancreatic cancer, colorectal cancer, malignant neoplasms of the kidney (except for renal pelvis tumors), malignant neoplasms of the brain, and malignant neoplasms of the esophagus (p > 0.05). Reverse MR helped mitigate reverse causation effects. Conclusions: The study indicates a divergent causal relationship of PCSK9 inhibitors with certain cancers. While negatively associated with breast and lung cancers, a positive causal association was observed with gastric, hepatic, oral cavity, and pharyngeal cancers and cervical carcinoma in situ. No causal links were found with bladder, thyroid, pancreatic, colorectal, certain kidney, brain, and esophageal cancers.

PCSK-9 inhibitors: a new direction for the future treatment of ischemic stroke.

Ischemic stroke, the most prevalent and serious manifestation of cerebrovascular disease, is the main cause of neurological problems that require hospitalization, resulting in disability and death worldwide. Currently, clinical practice focuses on the effective management of blood lipids as a crucial approach to preventing and treating ischemic stroke. In recent years, a great breakthrough in ischemic stroke treatment has been witnessed with the emergence and use of a novel lipid-lowering medication, Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitor. And its remarkable potential for reducing the occurrence of ischemic stroke is being acknowledged. This article aims to provide a comprehensive review, encompassing the association between PCSK9 and the heightened risk of ischemic stroke, the mechanisms, and the extensive evidence supporting the proven efficacy of PCSK9 inhibitors in clinical practice. Through this present study, we can gain deeper insights into the utilization and impact of PCSK9 inhibitors in treating ischemic stroke.

Atherosclerotic plaque stabilization and regression: a review of clinical evidence.

Atherosclerotic plaque results from a complex interplay between lipid deposition, inflammatory changes, cell migration and arterial wall injury. Over the past two decades, clinical trials utilizing invasive arterial imaging modalities, such as intravascular ultrasonography, have shown that reducing levels of atherogenic lipoproteins, mainly serum LDL-cholesterol (LDL-C), to very low levels can safely reduce overall atherosclerotic plaque burden and favourably modify plaque composition. Classically, this outcome has been achieved with intensive statin therapy. Since 2016, newer and potent lipid-lowering strategies, such as proprotein convertase subtilisin-kexin type 9 inhibition, have shown incremental effects on plaque regression and risk of clinical events. Despite maximal reduction in plasma LDL-C levels, considerable residual cardiovascular risk remains in some patients. Therefore, there is a need to study therapeutic approaches that address residual risk beyond LDL-C reduction to promote plaque stabilization or regression. Contemporary imaging modalities, such as coronary computed tomography angiography, enable non-invasive assessment of the overall atherosclerotic plaque burden as well as of certain local plaque characteristics. This technology could allow further study of plaque stabilization and regression using novel therapeutic approaches. Non-invasive plaque assessment might also offer the potential to guide personalized management strategies if validated for this purpose.

The role of proprotein convertase subtilisin/kexin 9 (PCSK9) in macrophage activation: a focus on its LDL receptor-independent mechanisms.

Recent clinical trials demonstrated that proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors reduce cardiovascular events without affecting systemic inflammation in the patients with coronary artery disease, as determined by high sensitivity C-reactive protein (CRP) levels. However, its pro-inflammatory effects in cardiovascular disease in humans and experimental animals beyond the traditional cholesterol receptor-dependent lipid metabolism have also called attention of the scientific community. PCSK9 may target receptors associated with inflammation other than the low-density lipoprotein receptor (LDLR) and members of the LDLR family. Accumulating evidence suggests that PCSK9 promotes macrophage activation not only via lipid-dependent mechanisms, but also lipid-independent and LDLR-dependent or -independent mechanisms. In addition to dyslipidemia, PCSK9 may thus be a potential therapeutic target for various pro-inflammatory diseases.

New target-HMGCR inhibitors for the treatment of primary sclerosing cholangitis: A drug Mendelian randomization study.

No intervention definitively extends transplant-free survival in primary sclerosing cholangitis (PSC). Statins, inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), may enhance PSC prognosis, but their efficacy is debated. We analyzed HMGCR single-nucleotide polymorphisms from published genome-wide association studies using Mendelian randomization to assess the causal relationship between HMGCR and PSC risk. Effects of HMGCR were compared with proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors, common lipid-lowering drugs, using coronary heart disease risk as a positive control. The inverse-variance weighted (IVW) method was the primary analysis, complemented by the weighted median method. Heterogeneity analysis, examination of horizontal pleiotropy, and leave-one-out sensitivity analysis were conducted for result robustness. Genetically predicted HMGCR exhibited a pronounced detrimental effect on PSC in both the IVW method (odds ratio [OR] [95%] = 2.43 [1.23-4.78], P = 0.010) and the weighted median method (OR [95%] = 2.36 [1.02-5.45], P = 0.044). However, PCSK9 did not reach statistical significance. Moreover, all analyses passed through heterogeneity analysis, horizontal pleiotropy analysis, and leave-one-out sensitivity analysis. This study has confirmed a causal relationship between HMGCR and PSC risk, suggesting statins targeting HMGCR could enhance PSC patient outcomes.

Safety and Efficacy of Proprotein Convertase Subtilisin-Kexin Type 9 Inhibitors After Acute Coronary Syndrome: A Meta-analysis of Randomized Controlled Trials.

Elevated circulating cholesterol levels in patients with acute coronary syndrome (ACS) increase morbidity and mortality. Recent studies reported that PCSK9 inhibitors (PCSK9i) have a beneficial effect on various domains of patients' lipid profiles and cardiovascular and mortality outcomes. Here, we aim to further investigate the efficacy and safety of PCSK9i in patients with ACS or who experienced recent episodes. We comprehensively searched PubMed, Scopus, Web of Science and Cochrane CENTRAL to identify all randomized controlled trials comparing PCSK9i versus placebo. Data were extracted and analysed using Stata/MP version 17.0. Eleven studies (n = 24,732) were included in this meta-analysis. In terms of efficacy outcomes, compared with the control group, PCSK9i significantly decreased levels of LDL-C, TC, TG, Lp (a) and Apo-B, with the following values, respectively: Cohen's d of - 1.25, 95% confidence interval (CI - 1.64 to - 0.87); Cohen's d of - 1.32, 95% CI (- 1.83 to - 0.81); Cohen's d of - 0.26, 95% CI (- 0.37 to - 0.14); Cohen's d of - 0.70, 95% CI (- 1.15 to - 0.26); and Cohen's d of - 1.46, 95% CI (- 1.97 to - 0.94). The levels of HDL-C and Apo-A1 increased by: Cohen's d 0.27, 95% CI (0.16-0.39) and Cohen's d of 0.30, 95% CI (0.17-0.42), respectively. Regarding safety outcomes, PCSK9i was associated with lower odds of myocardial infarction (MI) and cerebrovascular events with the following values, respectively: OR = 0.87, 95% CI (0.78-0.97) and OR = 0.71, 95% CI (0.52-0.98). PCSK9i was associated with better lipid profile and quality of life of patients and can be recommended as an optimal treatment strategy. Further trials should study combinations of PCSK9i with other lipid-lowering drugs.

Effectiveness of PCSK9 inhibitors: A Target Trial Emulation framework based on Real-World Electronic Health Records.

Low-Density Lipoprotein (LDL) cholesterol is one of the main target for cardiovascular (CV) prevention and therapy. In the last years, Proprotein Convertase Subtilisin-Kexin type 9 inhibitors (PCSK9-i) has emerged as a key therapeutic target to lower LDL and were introduced for prevention of CV events. Recently (June 2022) the Italian Medicines Agency (AIFA) modified the eligibility criteria for the use of PCSK9-i. We designed an observational study to estimate the prevalence of eligible subjects and evaluate the effectiveness of PCSK9-i applying a Target Trial Emulation (TTE) approach based on Electronic Health Records (EHR). Subjects meeting the eligibility criteria were identified from July 2017 (when PCSK9-i became available) to December 2020. Outcomes were all-cause death and the first hospitalization. Among eligible subjects, we identified those treated at date of the first prescription. Inverse Probability of Treatment Weights (IPTW) were estimated including demographic and clinical covariates, history of treatment with statins and the month/year eligibility date. Competing risk models on weighted cohorts were used to derive the Average Treatment Effect (ATE) and the Conditional Average Treatment Effect (CATE) in subgroups of interest. Out of 1976 eligible subjects, 161 (8%) received treatment with PCSK9-i. Treated individuals were slightly younger, predominantly male, had more severe CV conditions, and were more often treated with statin compared to the untreated subjects. The latter exhibited a higher prevalence of non-CV comorbidities. A significant absolute and relative risk reduction of death and a lower relative risk for the first hospitalization was observed. The risk reduction for death was confirmed in CATE analysis. PCSk9-i were prescribed to a minority of eligible subjects. Within the TTE framework, the analysis confirmed the association between PCSK9-i and lower risk of events, aligning with findings from randomized clinical trials (RCTs). In our study, PCSK9-i provided protection specifically against all-cause death, expanding upon the evidence from RCTs that had primarily focused on composite CV outcomes.

Extracellular vesicle-mediated delivery of CRISPR/Cas9 ribonucleoprotein complex targeting proprotein convertase subtilisin-kexin type 9 (Pcsk9) in primary mouse hepatocytes.

The loss-of-function of the proprotein convertase subtilisin-kexin type 9 (Pcsk9) gene has been associated with significant reductions in plasma serum low-density lipoprotein cholesterol (LDL-C) levels. Both CRISPR/Cas9 and CRISPR-based editor-mediated Pcsk9 inactivation have successfully lowered plasma LDL-C and PCSK9 levels in preclinical models. Despite the promising preclinical results, these studies did not report how vehicle-mediated CRISPR delivery inactivating Pcsk9 affected low-density lipoprotein receptor recycling in vitro or ex vivo. Extracellular vesicles (EVs) have shown promise as a biocompatible delivery vehicle, and CRISPR/Cas9 ribonucleoprotein (RNP) has been demonstrated to mediate safe genome editing. Therefore, we investigated EV-mediated RNP targeting of the Pcsk9 gene ex vivo in primary mouse hepatocytes. We engineered EVs with the rapamycin-interacting heterodimer FK506-binding protein (FKBP12) to contain its binding partner, the T82L mutant FKBP12-rapamycin binding (FRB) domain, fused to the Cas9 protein. By integrating the vesicular stomatitis virus glycoprotein on the EV membrane, the engineered Cas9 EVs were used for intracellular CRISPR/Cas9 RNPdelivery, achieving genome editing with an efficacy of ±28.1% in Cas9 stoplight reporter cells. Administration of Cas9 EVs in mouse hepatocytes successfully inactivated the Pcsk9 gene, leading to a reduction in Pcsk9 mRNA and increased uptake of the low-density lipoprotein receptor and LDL-C. These readouts can be used in future experiments to assess the efficacy of vehicle-mediated delivery of genome editing technologies targeting Pcsk9. The ex vivo data could be a step towards reducing animal testing and serve as a precursor to future in vivo studies for EV-mediated CRISPR/Cas9 RNP delivery targeting Pcsk9.

The effect of resistance training on PCSK9 levels in patients undergoing cardiac rehabilitation after coronary artery bypass grafting: a randomized study

BackgroundResistance training is commonly recommended as part of secondary prevention for post-coronary artery bypass graft (CABG) patients in conjunction with aerobic exercise. Despite its potential benefits, there is currently a lack of studies investigating the impact of resistance training on proprotein convertase subtilisin kexin 9 (PCSK9).AimTo evaluate the effect of intensive resistance training on proprotein convertase subtilisin kexin 9 (PCSK9) levels among post-CABG patients undergoing cardiac rehabilitation (CR).MethodsIn this prospective, open-label, randomized trial, 87 post-coronary artery bypass graft (CABG) patients were randomly assigned into two groups: moderate to high intensity resistance training and aerobic training (n = 44) or aerobic training alone (n = 43) for a total of 12 sessions. Changes in PCSK9 levels was determined as a primary endpoint, while secondary endpoints included changes in the six-minute walk test (6-MWT) results, aerobic capacity, WHO-5 well-being index, fasting blood glucose, and lipid profile. Both groups underwent intention-to-treat analysis.ResultsFollowing completion of cardiac rehabilitation program, the intervention group demonstrated a significant decrease in mean PCSK9 levels when compared to the control group (β = -55 ng/ml, 95% CI -6.7 to -103.3, p = 0.026), as well as significant improvements in the 6-MWT result (β = 28.2 m, 95% CI 2.4–53.9, p = 0.033), aerobic capacity (β = 0.9 Mets, 95% CI 0.1–1.7, p = 0.021), and WHO-5 well-being index (β = 8.1, 95% CI 2.0–14.4, p = 0.011) in patients who received resistance and aerobic training. No statistically significant changes were observed in fasting blood glucose, cholesterol, LDL-C, HDL-C, and triglyceride levels.ConclusionResistance training in CR significantly reduced PCSK­9 levels and increases patient’s functional capacity and quality of life. (NCT02674659 04/02/2016).

The effect of antibody-mediated PCSK9 inhibitor on bare-metal stent implantation outcome

Abstract Introduction Percutaneous coronary intervention (PCI) is the gold standard for the management of acute coronary syndrome, and has been benefited from advances in pharmacotherapy and device innovation. Nevertheless, in-stent restenosis and stent thrombosis remain serious complications following PCI procedure with stent implantation. Proprotein convertase subtilisin kexin type 9 (PCSK9) is an enzyme known for its role in plasma cholesterol homeostasis. Efficiently reducing plasma cholesterol, PCSK9 inhibition recently became a pivotal treatment strategy for hypercholesterolemia. However, the effect of PCSK9 inhibition on stent implantation outcomes remains uninvestigated. Methods Carotid artery bare-metal stent (BMS) implantation was performed on C57Bl/6 mice, which then a parallel assessment of various inflammatory mediators was performed. To inhibit PCSK9, alirocumab was administered weekly to antiplatelet-treated mice started before stent implantation. Six weeks after the stent implantation procedure, animals were harvested and histomorphometric analysis was performed on stented arteries. In vitro cell migration and cellular senescence were also assessed on alirocumab-treated primary human aortic endothelial (EC) and vascular smooth muscle cells (VSMC). Results Compared to sham intervention, stent implantation was associated with increased expression of several inflammatory mediators, including PCSK9. Interestingly, the increase in PCSK9 level was confirmed in the stented vascular tissue, but not in plasma (Fig 1A). Following alirocumab treatment, PCSK9 inhibition results in an increased intimal hyperplasia in the stented vascular segment of alirocumab-treated animals compared to controls (Fig 1B). In vitro, alirocumab promoted migration and inhibited the onset of senescence in primary human VSMC, while blunted the migration and increased the senescence of EC. Conclusion The results of this study demonstrated that antibody-based PCSK9 inhibition worsen bare-metal stent implantation outcome in mice. This observed effect is mediated, in part, by the differential effect on VSMC and EC senescence, thus promoting in-stent intimal hyperplasia while blunting vascular healing. The herein-reported data warrant additional investigations concerning the use of PCSK9 inhibitors in patients undergoing PCI with stent implantation.

Course of the effects of LDL-cholesterol reduction on cardiovascular risk over time: a meta-analysis of 59 trials

Abstract Background Therapies lowering low-density lipoprotein cholesterol (LDL-c) are widely used to reduce cardiovascular disease (CVD) risk in patients with or at high risk of CVD. Therapy is usually continued lifelong, but whether the effects of LDL-c reduction remain stable over time is uncertain. This study aimed to establish the course of the relative treatment effects of LDL-c reduction on cardiovascular risk over time, i.e. treatment duration and age. Methods Randomized controlled trials (RCTs) of LDL-c lowering therapies were identified through a search in MEDLINE and EMBASE (1966-January 2023). RCTs of guideline-recommended therapies (i.e. statins, ezetimibe, and proprotein convertase subtilisin–kexin type 9 inhibitors [PCSK9i]) were selected for the primary analyses, with RCTs of other therapies included in sensitivity analyses. Random-effects meta-analyses were performed to establish the average relative risk (RR) for major vascular events (cardiovascular death, myocardial infarction or other acute coronary syndrome, coronary revascularization, or stroke) per 1 mmol/L LDL-c reduction. Course of the effects over time was assessed using random-effects meta-regression analyses for the association between follow-up duration, age, and the RR for major vascular events per 1 mmol/L LDL-c reduction. Analyses were also stratified for primary and secondary prevention. Results A total of 59 trials (26 statin trials, 2 ezetimibe trials, 3 statin/ezetimibe combination trials, 7 PCSK9i trials, and 21 other trials) were selected, including 394,989 participants and 49,642 major vascular events. Mean follow-up was 3.9 years (range 0.9-9.7), and age was 63.8 years (range 48.0-77.0). The average RR for major vascular events per 1 mmol/L LDL-c reduction was 0.78 (95% confidence interval [CI] 0.75-0.81), with slightly larger risk reductions in primary (RR 0.74; 95% CI 0.68-0.81) as compared to secondary prevention (RR 0.80; 95% CI 0.77-0.83). Follow-up duration was not associated with the RR for major vascular events (p = 0.615), with the meta-regression line showing a stable RR over follow-up time (RR for change per year 0.994; 95% CI 0.971-1.017). The RR for major vascular events increased (i.e. risk reduction decreased) with age in primary prevention (RR for change per 5 years 1.094; 95% CI 1.028-1.165; p = 0.018), but remained largely unchanged in secondary prevention (RR for change per 5 years 0.986; 95% CI 0.943-1.031; p = 0.533). Consistent results were found for statin trials only, and all trials combined. Conclusions The relative treatment effects of LDL-c reduction are stable over time in secondary prevention, but may decrease with age in primary prevention.Meta-analysisMeta-regression analyses

Identification of benzothiazoles as novel PCSK9 inhibitors

Proprotein convertase subtilisin kexin type 9 (PCSK9) is a clinically validated target on the treatment of cardiovascular disease (CVD). PCSK9 can regulate the hepatocyte surface low density lipoprotein receptor (LDLR) level by binding to LDLR and leading to their degradation in the lysosome. The clinical use of two monoclonal antibodies (alirocumab and evolocumab, approved in 2015) and one small interfering RNA (inclisiran, approved in 2020) which can inhibit PCSK9 function proved that they are very effective in lowering low density lipoprotein cholesterol (LDL-C). However, the high treatment costs and parenteral administration of these drugs prohibited widespread use and reduced their long-term advantage. Comparatively, small molecule drugs have many incomparable advantages of macromolecules, such as lower treatment cost, more drug administration options, superior pharmacokinetic properties, less adverse immunogenic responses and better affordable production. In this paper, we identified a series of benzothiazoles small molecule PCSK9 inhibitors through extensive screening. The structure and activity relationship (SAR) was summarized to facilitate further optimization. Moreover, the primary mechanism of action of the most potent compound was also investigated.

Abstract 16485: Treatment With PCSK9 Inhibitors Influence miRNAs Expression and Changes of Arterial Wall Properties

Background and aim: MicroRNAs (miRNAs) are involved in the synthesis of proprotein convertase subtilisin-kexin type 9(PCSK9), which is one of regulators of low-density lipoprotein cholesterol (LDL-C) metabolism. There is no data on whether changes in the expression of miRNAs involved in PCSK9 metabolism, could be related to arterial wall properties changes. The aim was to verify whether PCSK9 inhibitors (PCSK9i) treatment and the changes in the expression of miRNAs are associated with arterial wall properties in post-myocardial infarction (MI) patients with insufficiently regulated LDL-C levels and increased Lp(a) levels. Methods: Seventy-six participants after MI were enrolled and randomized to a placebo group or PCSK9i group. The treatment group received subcutaneous alirocumab 150 mg or evolokumab 140 mg, every 2 weeks. Blood for biochemical and genetic analysis was taken and ultrasound measurements of flow-mediated dilation of brachial artery (FMD), carotid intima-media thickness (c-IMT) and pulse wave velocity (PWV) were performed. All measurements were measured initially and after 6 months of treatment. Results: FMD improved from 10.9±6.3 to 14.4±5.7% in the PCSK9i group and 10.8±6.8 to 11.2±4.6% in the placebo group (p<0.001, p=0.584). PWV changed from 5.8±1.4 to 5.5±1.6 m/s (p=0.024) in the PCSK9i group and in the placebo group from 5.6±1.5 to 5.5±1.1 m/s (p=0.879), with better improvement in the treated group (p=0.007). c-IMT decreased in the PCSK9i group (from 0.65±0.10 to 0.63±0.10 mm; p=0.017), with no change in the placebo group (from 0.64±0.09 to 0.63±0.09 mm; p=0.482). The expression of miR-191-5p and miR-483-5p increased in the PCSK9i group (p=0.028, p=0.020; respectively). The expression of miR-191-5p significantly decreased in the placebo group (p< 0.001). A decrease in c-IMT was associated with a decrease in the expression of miR-224-5p (r=0.303; p=0.019), miR-337-3p (r=0.329; p=0.010) and miR-483-5p (r=0.367; p=0.004). Conclusions: Our results suggest that changes in selected miRNAs were associated with changes in the morphological properties of the arterial vessel wall. We have shown that the increase in miR-483-5p expression can be a good indicator of the regression of morphological atherosclerotic changes.

Schisandrin A in Schisandra chinensis Upregulates the LDL Receptor by Inhibiting PCSK9 Protein Stabilization in Steatotic Model.

Schisandra chinensis extract (SCE) protects against hypocholesterolemia by inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) protein stabilization. We hypothesized that the hypocholesterolemic activity of SCE can be attributable to upregulation of the PCSK9 inhibition-associated low-density lipoprotein receptor (LDLR). Male mice were fed a low-fat diet or a Western diet (WD) containing SCE at 1% for 12 weeks. WD increased final body weight and blood LDL cholesterol levels as well as alanine transaminase and aspartate aminotransferase expression. However, SCE supplementation significantly attenuated the increase in blood markers caused by WD. SCE also attenuated WD-mediated increases in hepatic LDLR protein expression in the obese mice. In addition, SCE increased LDLR protein expression and attenuated cellular PCSK9 levels in HepG2 cells supplemented with delipidated serum (DLPS). Non-toxic concentrations of schisandrin A (SA), one of the active components of SCE, significantly increased LDLR expression and tended to decrease PCSK9 protein levels in DLPS-treated HepG2 cells. High levels of SA-mediated PCSK9 attenuation was not attributable to reduced PCSK9 gene expression, but was associated with free PCSK9 protein degradation in this cell model. Our findings show that PCSK9 secretion can be significantly reduced by SA treatment, contributing to reductions in free cholesterol levels.