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 in vitro, 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.

PCSK9 inhibitors as safer therapeutics for atherosclerotic cardiovascular disease (ASCVD): Pharmacophore design and molecular dynamics analysis.

Cardiovascular disorders are still challenging and are among the deadly diseases. As a major risk factor for atherosclerotic cardiovascular disease, dyslipidemia, and high low-density lipoprotein cholesterol in particular, can be prevented primary and secondary by lipid-lowering medications. Therefore, insights are still needed into designing new drugs with minimal side effects. Proprotein convertase subtilisin/kexin 9 (PCSK9) enzyme catalyses protein-protein interactions with low-density lipoprotein, making it a critical target for designing promising inhibitors compared to statins. Therefore, we screened for potential compounds using a redesigned PCSK9 conformational behaviour to search for a significantly extensive chemical library and investigated the inhibitory mechanisms of the final compounds using integrated computational methods, from ligand essential functional group screening to all-atoms MD simulations and MMGBSA-based binding free energy. The inhibitory mechanisms of the screened compounds compared with the standard inhibitor. K31 and K34 molecules showed stronger interactions for PCSK9, having binding energy (kcal/mol) of -33.39 and -63.51, respectively, against -27.97 of control. The final molecules showed suitable drug-likeness, non-mutagenesis, permeability, and high solubility values. The C-α atoms root mean square deviation and root mean square fluctuation of the bound-PCSK9 complexes showed stable and lower fluctuations compared to apo PCSK9. The findings present a model that unravels the mechanism by which the final molecules proposedly inhibit the PCSK9 function and could further improve the design of novel drugs against cardiovascular diseases.

Far-infrared irradiation increases the uptake of LDL cholesterol by downregulating PCSK9 through the activation of TRPV4 calcium channels in HepG2 cells.

This study investigated the effects of far-infrared (FIR) irradiation on low-density lipoprotein cholesterol (LDL-C) uptake by human hepatocellular carcinoma G2 (HepG2) cells via the regulation of proprotein convertase subtilisin/kexin type 9 (PCSK9). FIR irradiation for 30 min significantly decreased PCSK9 expression (p < 0.01) in HepG2 cells. FIR irradiation substantially increased the low-density lipoprotein receptor (p < 0.0001) and LDL-C uptake (p < 0.01). Activation of transient receptor potential vanilloid (TRPV) channels mimicked the effects of FIR irradiation, significantly decreasing the protein expression of PCSK9 (p < 0.05). Conversely, inhibition of TRP channels using ruthenium red reversed the reduction in PCSK9 protein expression following FIR irradiation (p < 0.01). The specific activation of TRPV4 using 4α-PDD mimicked the effect of FIR irradiation (p < 0.01), whereas PCSK9 reduction by FIR irradiation was significantly reversed by the inhibition of TRPV4 using RN1734 (p < 0.05). These findings implied that FIR irradiation emitted from a ceramic lamp specifically increased TRPV4 activity. These findings provide insights into a novel therapeutic approach using FIR irradiation for LDL-C regulation and its implications for cardiovascular health.

PCSK9 Inhibitor Added to High-Intensity Statin Therapy to Prevent Cardiovascular Events in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: A Randomized, Double- Blind, Placebo-Controlled, Multicenter SHAWN Study.

BACKGROUND: It is currently uncertain whether the combination of a proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor and high-intensity statin treatment can effectively reduce cardiovascular events in patients with acute coronary syndrome (ACS) who have undergone percutaneous coronary intervention (PCI) for culprit lesions. METHODS: This study protocol describes a double-blind, randomized, placebo-controlled, multicenter study aiming to investigate the efficacy and safety of combining a PCSK9 inhibitor with high-intensity statin therapy in patients with ACS following PCI. A total of 1212 patients with ACS and multiple lesions will be enrolled and randomly assigned to receive either PCSK9 inhibitor plus high-intensity statin therapy or high-intensity statin monotherapy. The randomization process will be stratified by sites, diabetes, initial presentation and use of stable (≥4 weeks) statin treatment at presentation. PCSK 9 inhibitor or its placebo is injected within 4 hours after PCI for the culprit lesion. The primary endpoint is the composite of cardiovascular death, myocardial infarction, stroke, re-hospitalization due to ACS or heart failure, or any ischemia-driven coronary revascularization at one-year follow-up between two groups. Safety endpoints mean PCSK 9 inhibitor and statin intolerance. CONCLUSION: The SHAWN study has been specifically designed to evaluate the effectiveness and safety of adding a PCSK9 inhibitor to high-intensity statin therapy in patients who have experienced ACS following PCI. The primary objective of this study is to generate new evidence regarding the potential benefits of combining a PCSK9 inhibitor with high-intensity statin treatment in reducing cardiovascular events among these patients.

Genetic backgrounds and diagnosis of familial hypercholesterolemia.

Lipid disorders play a critical role in the intricate development of atherosclerosis and its clinical consequences, such as coronary heart disease and stroke. These disorders are responsible for a significant number of deaths in many adult populations worldwide. Familial hypercholesterolemia (FH) is a genetic disorder that causes extremely high levels of LDL cholesterol. The most common mutations occur in genes responsible for low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin/kexin type 9 (PCSK9). While genetic testing is a dependable method for diagnosing the disease, it may not detect primary mutations in 20%-40% of FH cases.

Review of Evolocumab for the Reduction of LDL Cholesterol and Secondary Prevention of Atherosclerotic Cardiovascular Disease.

Elevated low-density lipoprotein cholesterol (LDL-C) is a major causal factor for atherosclerotic cardiovascular disease (ASCVD), the leading cause of mortality worldwide. Statins are the recommended first-line lipid-lowering therapy (LLT) for patients with primary hypercholesterolemia and established ASCVD, with LLT intensification recommended in the substantial proportion of patients who do not achieve levels below guideline-recommended LDL-C thresholds with statin treatment alone. The proprotein convertase subtilisin/kexin type 9 inhibitor monoclonal antibody evolocumab has demonstrated significant LDL-C reductions of > 60% in the clinical trial and open-label extension settings, with LDL-C reductions observed early post-evolocumab initiation and maintained long term, during up to 8.4 years of follow-up. Evolocumab therapy, when added to a statin, also conferred a significant reduction in major cardiovascular (CV) events, including a 20% reduction in the composite of CV death, myocardial infarction (MI), or stroke. The absolute benefits were enhanced among various patient types at high and very high risk for secondary ASCVD (e.g., with recent MI, multiple events or peripheral artery disease). Importantly, evolocumab treatment resulted in incremental CV risk reductions during the extended follow-up, including a 23% reduction in CV mortality and no apparent LDL-C level below which there is no further CV risk reduction. Hence, the evolocumab clinical data support the need for early and significant LDL-C lowering, especially in vulnerable ASCVD patients, in order to derive the greatest benefit in the long term. Importantly, evolocumab had no impact on any treatment emergent adverse events apart from a small increase in local injection site reactions. A growing body of real-world evidence (RWE) for evolocumab in heterogeneous populations is consistent with the trial data, including robust LDL-C reductions below guideline-recommended thresholds, a favourable safety profile even at the lowest levels of LDL-C achieved, and a high treatment persistence rate of > 90%. Altogether, this review highlights findings from 50 clinical trials and RWE studies in > 51,000 patients treated with evolocumab, to demonstrate the potential of evolocumab to address the healthcare gap in LDL-C reduction and secondary prevention of ASCVD in a variety of high- and very high-risk patients.

Association of lipid-lowering drug targets with risk of cutaneous melanoma: a mendelian randomization study.

BACKGROUND: Melanoma proliferation is partly attributed to dysregulated lipid metabolism. The effectiveness of lipid-lowering drugs in combating cutaneous melanoma (CM) is a subject of ongoing debate in both in vitro and clinical studies. METHOD: This study aims to evaluate the causal relationship between various lipid-lowering drug targets, namely 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR, targeted by statins), Proprotein convertase subtilisin/kexin type 9 (PCSK9, targeted by alirocumab and evolocumab), and Niemann-Pick C1-like 1 (NPC1L1, targeted by ezetimibe), and the outcomes of cutaneous melanoma. To mimic the effects of lipid-lowering drugs, we utilized two genetic tools: analysis of polymorphisms affecting the expression levels of drug target genes, and genetic variations linked to low-density lipoprotein cholesterol levels and drug target genes. These variations were sourced from genome-wide association studies (GWAS). We applied Summary-data-based Mendelian Randomization (SMR) and Inverse Variance Weighted Mendelian Randomization (IVW-MR) to gauge the effectiveness of these drugs. RESULTS: Our findings, with SMR results showing an odds ratio (OR) of 1.44 (95% CI: 1.08-1.92; P = 0.011) and IVW-MR results indicating an OR of 1.56 (95% CI: 1.10-2.23; P = 0.013), demonstrate a positive correlation between PCSK9 expression and increased risk of CM. However, no such correlations were observed in other analyses. CONCLUSION: The study concludes that PCSK9 plays a significant role in the development of CM, and its inhibition is linked to a reduced risk of the disease.

PCSK9 causes inflammation and cGAS/STING pathway activation in diabetic nephropathy.

Our previous research revealed that an increase in PCSK9 is linked to aggravated inflammation in the kidneys of mice affected by a high-fat diet and streptozotocin (HFD/STZ) or in HGPA-induced HK-2 cells. Furthermore, the cGAS/STING pathway has been reported to be involved in diabetic nephropathy (DN). Therefore, in this study, we aimed to examine the correlation between the proinflammatory effect of PCSK9 and the cGAS/STING pathway in DN. We used PCSK9 mAbs to inhibit PCSK9 in vivo and PCSK9 siRNA in vitro and measured the inflammatory phenotype in HFD/STZ-treated mice or HGPA-induced HK-2 cells, and observed decreased blood urea nitrogen, creatinine, UACR, and kidney injury in response to the PCSK9 mAb in HFD/STZ-treated mice. Moreover, IL-1 ß, MCP-1, and TNF-α levels were reduced by the PCSK9 mAb in vivo and PCSK9 siRNA in vitro. We observed increased mtDNA damage and activation of the cGAS-STING signaling pathway during DN, as well as the downstream targets p-TBK1, p-NF-κB p65, and IL-1ß. In a further experiment with an HGPA-induced DN model in HK-2 cells, we revealed that mtDNA damage was increased, which led to the activation of the cGAS/STING system and its downstream targets. Notably, the cGAS-STING signaling pathway was inhibited by the PCSK9 mAb in vivo and PCSK9 siRNA in vitro. In addition, inhibition of STING with C-176 in HGPA-induced HK-2 cells markedly blocked inflammation. In conclusion, we report for the first time that PCSK9 triggers mitochondrial DNA damage and activates the cGAS-STING pathway in DN, which leads to a series of inflammation cascades. PCSK9-targeted intervention can effectively reduce DN inflammation and delay its progression. Moreover, the inhibition of STING significantly abrogated the inflammation triggered by HGPA in HK-2 cells.

Ebronucimab in Chinese Patients with Hypercholesterolemia---A Randomized Double-Blind Placebo-Controlled Phase 3 Trial to Evaluate the Efficacy and Safety of Ebronucimab.

Randomized clinical trials (RCTs) of PCSK9 monoclonal antibody(mAb) specifically for Chinese patients have been limited. This multi-center RCT is to clarify the efficacy and safety of a novel mAb, Ebronucimab, in Chinese patients. Patients diagnosed with primary hypercholesterolemia, including Heterozygous Familial Hypercholesterolemia, or mixed dyslipidemia, were categorized by ASCVD risk and randomly assigned at a ratio of 2:1:2:1 to receive Ebronucimab 450mg or matching placebo every 4 weeks (Q4W), or Ebronucimab 150mg or matching placebo every 2 weeks (Q2W). The primary outcome was the percentage change of LDL-C from baseline to week 12 for all groups. The least squares mean reduction difference (95%CI) in LDL-C from baseline to week 12 of Ebronucimab 450mg Q4W and Ebronucimab 150mg Q2W groups versus the placebo group was -59.13 (-64.103, -54.153) (Adjusted p<0.0001) and -60.43 (-65.450, -55.416) (Adjusted p<0.0001), respectively. Meanwhile, the Ebronucimab group exhibited notably high rates in reaching LDL-C goals of each cardiovascular risk stratification. In addition, Ebronucimab effectively improved other lipid panel. During the double-blind treatment period, relatively frequently reported adverse events (AEs) were injection site reactions (ISR), urinary tract infection, and hyperuricemia (Incidence rate are 6.9%, 4.8% and 3.5%). Among treatment-associated AEs, only injection site reactions (ISR) occurred more in the dose groups. In conclusion, Ebronucimab, with either 450mg Q4W or 150mg Q2W doses, demonstrated significant efficacy in lowering serum LDL-C level with a favorable safety and immunogenicity profile among hypercholesterolemic patients. Trial Registration：ClinicalTrials.gov Identifier: NCT05255094.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Is Associated With Recurrence and Survival of Resectable Non-Small Cell Lung Cancer (NSCLC): A Retrospective Study.

INTRODUCTION: Curative lung resection remains the key therapeutic strategy for early-stage non-small cell lung cancer (NSCLC). However, a proportion of patients still experience variable outcomes and eventually develop recurrence or die from their disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been identified as a deleterious factor that inhibits tumor cells apoptosis and leads to reduction of lymphocyte infiltration. However, there has been no research on the predicted role of PCSK9 as an immunohistochemical biomarker with survival in resectable NSCLC. METHODS: One hundred sixty-three patients with resectable NSCLC were retrospectively reviewed, and PCSK9 expression of resected NSCLC was analyzed by immunohistochemistry using tissue microarrays. RESULTS: PCSK9 was associated with recurrence (42.1% relapsed in the PCSK9lo group versus 57.9% relapsed in the PCSK9hi group, P = 0.006) and survival status (39.6% dead in PCSK9lo group versus 60.4% dead in PCSK9hi group, P = 0.004) in patients with resectable NSCLC. Moreover, resectable NSCLC patients with higher PCSK9 expression in tumor tissue experienced poorer disease-free survival (median disease-free survival: 10.5 versus 25.2 mo, hazard ratio = 1.620, 95% confidence interval: 1.124-2.334) and overall suvrival (median overall suvrival: 20.0 versus 54.1 mo, hazard ratio = 1.646, 95% confidence interval: 1.101-2.461) compared to those with lower PCSK9 expression. CONCLUSIONS: High PCSK9 expression of tumor was correlated with recurrence and worse survival status of resectable NSCLC in our retrospective study, which indicated that PCSK9 in NSCLC may be an immunohistochemical biomarker of poor prognosis for patients with resectable NSCLC. Further large-scale prospective studies are warranted to establish these results.

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.

Real-World Clinical Profile of Patients Prescribed Evolocumab in Japan.

BACKGROUND: Real-world utilization data for evolocumab, the first proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor to be introduced in Japan in 2016, to date are limited. This study aimed to clarify the current real-world patient user profiles of evolocumab based on large-scale health claims data.Methods and Results: This retrospective database study examined patients from a health administrative database (MDV database) who initiated evolocumab between April 2016 (baseline) and November 2021. Characteristics and clinical profiles of this patient population are described. In all, 4,022 patients were included in the final analysis. Most evolocumab prescriptions occurred in the outpatient setting (3,170; 78.82%), and 940 patients (23.37%) had a recent diagnosis of familial hypercholesterolemia. Common recent atherosclerotic cardiovascular disease events at baseline included myocardial infarction (1,633; 40.60%), unstable angina (561; 13.95%), and ischemic stroke (408; 10.14%). Comorbidity diseases included hypertension (2,504; 62.26%), heart failure (1,750; 43.51%), diabetes (1,199; 29.81%), and chronic kidney disease (297; 7.38%). Among the lipid-lowering regimens concomitant with evolocumab, ezetimibe+statin was used most frequently (1,281; 31.85%), followed by no concomitant lipid-lowering regimen (1,190; 29.59%), statin (950; 23.62%), and ezetimibe (601; 14.94%). The median evolocumab treatment duration for all patients was 260 days (interquartile range 57-575 days). CONCLUSIONS: This study provides real-world insights into evolocumab utilization in Japan for optimizing patient care and adherence to guideline-based therapies to better address hypercholesterolemia in Japan.

TEAD4 Activates PCSK9 to Promote Stomach Adenocarcinoma Cell Stemness through Fatty Acid Metabolism.

INTRODUCTION: This study attempted to investigate how proprotein convertase subtilisin/kexin type 9 (PCSK9) influences the stemness of stomach adenocarcinoma (STAD) cells. METHODS: CCK-8 and sphere-formation assays were used to detect cell viability and stemness. qRT-PCR and Western blot were used to detect PCSK9 and TEAD4 expression. The binding relationship was verified by dual-luciferase and chromatin immunoprecipitation assays. The effect of TEAD4 activating PCSK9 on the stemness of STAD cells was detected by bioinformatics, BODIPY 493/503, Oil red O, Western blot, and kits. In vivo experiments verified the role of the TEAD4/PCSK9 axis in tumor formation in nude mice. RESULTS: PCSK9 and TEAD4 were highly expressed in STAD. PCSK9 was enriched in the fatty acid metabolism (FAM) pathway. PCSK9 activated the fatty acid metabolism and promoted the proliferation and stemness of STAD cells. TEAD4 as a transcription factor upstream of PCSK9, cell experiments revealed that knockdown of PCSK9 inhibited STAD cell stemness, whereas further addition of fatty acid inhibitors could attenuate the promoting effect on STAD cell stemness brought by STAD overexpression. Rescue experiments showed overexpressed PCSK9 exerted an inhibitory effect on the stemness of STAD cells brought by TEAD4 knockdown. The hypothesis that TEAD4/PCSK9 axis can promote STAD cell growth was confirmed by in vivo experiments. CONCLUSION: Transcription factor TEAD4 could activate PCSK9 to promote the stemness of STAD cells through FAM. These results added weight to the assumption that TEAD4/PCSK9 axis has the potential to be the therapeutic target that inhibits cancer stem cell in STAD.

Association between evolocumab use and slow progression of aortic valve stenosis.

No medications have been reported to inhibit the progression of aortic valve stenosis (AS). The present study aimed to investigate whether evolocumab use is related to the slow progression of AS evaluated by serial echocardiography. This was a retrospective observational study from 2017 to 2022 at Yokohama City University Medical Center. Patients aged ≥ 18 with moderate AS were included. Exclusion criteria were (1) mild AS; (2) severe AS defined by maximum aortic valve (AV) velocity ≥ 4.0 m/s; and/or (3) no data of annual follow-up echocardiography. The primary endpoint was the association between evolocumab use and annual changes in the maximum AV-velocity or peak AV-pressure gradient (PG). A total of 57 patients were enrolled: 9 patients treated with evolocumab (evolocumab group), and the other 48 patients assigned to a control group. During a median follow-up of 33 months, the cumulative incidence of AS events (a composite of all-cause death, AV intervention, or unplanned hospitalization for heart failure) was 11% in the evolocumab group and 58% in the control group (P = 0.012). Annual change of maximum AV-velocity or peak AV-PG from the baseline to the next year was 0.02 (- 0.18 to 0.22) m/s per year or 0.60 (- 4.20 to 6.44) mmHg per year in the evolocumab group, whereas it was 0.29 (0.04-0.59) m/s per year or 7.61 (1.46-16.48) mmHg per year in the control group (both P < 0.05). Evolocumab use was associated with slow progression of AS and a low incidence of AS events in patients with moderate AS.

Early Use of PCSK9 Inhibitors in the Prognosis of Patients with Acute Coronary Syndrome by Protecting Vascular Endothelial Function.

INTRODUCTION: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) has a protective effect on acute coronary syndrome (ACS). However, most studies have shown that this protective effect is based on a decrease in low-density lipoprotein cholesterol, while other mechanisms remain limited. This study aimed to determine whether PCSK9i can improve the prognosis of ACS patients by protecting endothelial function. METHODS: A total of 113 ACS patients were enrolled and randomly assigned to PCSK9i group (PCSK9i combined with statins) and control group (statins only). Blood lipids and endothelial function indicators were measured and analyzed 6 weeks before and after treatment. The effect of PCSK9i on the expression and secretion of endothelial function indicators in vascular endothelial cells were studied by cell experiments. RESULTS: After 6 weeks of treatment, endothelial function indicators such as nitric oxide (NO), thrombomodulin, intercellular cell adhesion molecule-1, endothelin-1, and flow-mediated vasodilation were significantly improved in PCSK9i group compared with control group. Only the changes of NO and von Willebrand factor were associated with blood lipid levels, whereas the changes of other endothelial function indicators were not significantly associated with blood lipid levels. PCSK9i reduced the incidence of major adverse cardiovascular events in patients with ACS compared to those in the control group. In cell experiments, PCSK9i treatment significantly ameliorated LPS induced endothelial injury in HUVECs. CONCLUSION: PCSK9i can protect vascular endothelial function partly independently of its lipid-lowering effect and ameliorate the prognosis of patients with ACS within 6 weeks. This mechanism may involve heat shock transcription factor 1/heat shock proteins -related signaling pathways. Early use of PCSK9i in patients with ACS should be strongly considered in clinical practice.

Updates on Non-Statin LDL-Lowering Therapy.

PURPOSE OF REVIEW: There is ample evidence of the benefits and safety of low-density lipoprotein (LDL)-lowering therapies in the prevention of atherosclerotic cardiovascular disease. While statins remain the first-line agent for LDL reduction, several new therapies are now available. This narrative review provides an overview of currently available non-statin LDL-lowering agents, specifically mechanisms of action and data on efficacy and safety. It also discusses recommendations on their use in clinical practice. RECENT FINDINGS: Ezetimibe, PCSK9 inhibitors, and bempedoic acid have proven safe and efficacious in reducing cardiovascular events in large randomized controlled trials. Inclisiran is a promising agent that suppresses PCSK9 mRNA translation and is currently under investigation in a large clinical outcomes randomized controlled trial assessing its effect on clinical outcomes. Expert consensus advocates for lower LDL targets in higher risk patients and escalation to or a combination of non-statin therapies as needed to achieve these goals.

The Impact of PCSK9 Gene Polymorphisms on Ischemic Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: Single-nucleotide polymorphisms (SNPs) in the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene are known to be associated with susceptibility to several cerebrovascular diseases, including ischemic stroke (IS). The aims of this study was to evaluate associations between PCSK9 gene polymorphisms and the risk of IS. Based on previous reports linking PCSK9 SNPs to plasma lipid levels and to atherosclerosis, and to inconsistencies in the reported associations between the SNPs, plasma lipid levels and IS risk, we choose the PCSK9 rs505151, rs529787, and rs17111503 to performe the association analysis. METHODS: Using multiple databases, all relevant case-control and cohort studies that matched our search criteria were collected. Quality assessment of included studies was performed using the Newcastle-Ottawa Scale. Demographic and genotype data were extracted from each study, and meta-analysis was performed using Stata/MP 17.0. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed and random effects models. RESULTS: A critical evaluation was conducted on ten case-control studies, involving a total of 2426 cases and 2424 controls. Pooled results from the allelic models indicated the PCSK9 rs505151 G allele (OR: 1.41, 95% CI: 1.06-1.87, p = 0.019, I2 = 53.9%) and the PCSK9 rs17111503 A allele (OR: 1.38, 95% CI: 1.22-1.55, p < 0.001, I2 = 43.5%) were significantly associated with IS. Study qualities ranged from moderate (n = 4) to good (n = 6). Begg's and Egger's tests results indicated there was no evidence of publication bias in the findings (p > 0.05). CONCLUSIONS: This meta-analysis demonstrated that G allele variant of PCSK9 rs505151 and A allele variant of PCSK9 rs17111503 were associated with an increased risk of IS. Based on our findings, these SNPs could serve as potential targets for the diagnosis and treatment of IS. The integration of information on genetic polymorphism into IS risk prediction model may be beneficial in routine clinical practice.

Function of proprotein convertase subtilisin/kexin type 9 and its role in central nervous system diseases: An update on clinical evidence.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has attracted lots of attention in preventing the clearance of plasma low-density lipoprotein cholesterol (LDL-C). PCSK9 inhibitors are developed to primarily reduce the cardiovascular risk by lowering LDL-C level. Recently, a number of pleiotropic extrahepatic functions of PCSK9 beyond the regulation of cholesterol metabolism, particularly its effects on central nervous system (CNS) diseases have been increasingly identified. Emerging clinical evidence have revealed that PCSK9 may play a significant role in neurocognition, depression, Alzheimer's disease, and stroke. The focus of this review is to elucidate the functions of PCSK9 and highlight the effects of PCSK9 in CNS diseases, with the aim of identifying the potential risks that may arise from low PCSK9 level (variant or inhibitor) in the clinical practice.

Efficacy of Alirocumab, Evolocumab, and Inclisiran in Patients with Hypercholesterolemia at Increased Cardiovascular Risk.

Background and Objectives: Lowering low-density lipoprotein (LDL-C) levels is critical for preventing atherosclerotic cardiovascular disease, yet some patients fail to reach the LDL-C targets despite available intensive lipid-lowering therapies. This study assessed the effectiveness and safety profile of alirocumab, evolocumab, and inclisiran in lipid reduction. Materials and Methods: A cohort of 51 patients (median (Q1-Q3) age: 49.0 (39.5-57.5) years) was analyzed. Eligibility included an LDL-C level > 2.5 mmol/L while on the maximum tolerated dose of statin and ezetimibe, a diagnosis of familial hypercholesterolemia, or a very high risk of cardiovascular diseases following myocardial infarction within 12 months prior to the study. Follow-ups and lab assessments were conducted at baseline (51 patients), 3 months (51 patients), and 15 months (26 patients) after the treatment initiation. Results: Median initial LDL-C levels 4.1 (2.9-5.0) mmol/L, decreasing significantly to 1.1 (0.9-1.6) mmol/L at 3 months and 1.0 (0.7-1.8) mmol/L at 15 months (p < 0.001). Total cholesterol also reduced significantly compared to baseline at both intervals (p < 0.001). No substantial differences in LDL-C or total cholesterol levels were observed between 3- and 15-month observations (p > 0.05). No statistically significant differences were noted in cholesterol reduction among the alirocumab, evolocumab, and inclisiran groups at 3 months. The safety profile was favorable, with no reported adverse cardiovascular events or significant changes in alanine transaminase, creatinine, or creatine kinase levels. Conclusions: Alirocumab, evolocumab, and inclisiran notably decreased LDL-C and total cholesterol levels without significant adverse effects, underscoring their potential as effective treatments in patients who do not achieve lipid targets with conventional therapies.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor Improves the Vascular Function of Arteriovenous Fistula in Rats with Hyperglycemia.

Objectives: Few evidence-based medications to improve the primary patency of arteriovenous fistulas in patients with diabetes who require hemodialysis are available. We investigated whether proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) could improve arteriovenous fistula function through pleiotropic effects in a rat model of hyperglycemia. Methods: Ex vivo effects of PCSK9i on the aorta of Sprague-Dawley (SD) rats were investigated using an organ bath system. For in vivo experiments, an abdominal aortocaval (AC) fistula was generated in SD rats (200-250 g) after inducing hyperglycemia through streptozotocin administration (80 mg/kg, intraperitoneal). Alirocumab (50 mg/kg/week, subcutaneous) was administered on the day of fistula surgery and day 7. Echocardiography, blood flow through the aorta-limb, vasomotor reactivity, and serum biochemistry were examined on D14. Furthermore, enzyme-linked immunosorbent assay and immunoblotting were performed. Results: PCSK9i induced aorta relaxation ex vivo through a potassium channel-associated mechanism. PCSK9i significantly improved blood flow and preserved endothelial function without changes in cardiac function and serum lipid levels in rats with hyperglycemia. The levels of lectin-like oxidized low-density lipoprotein receptor-1, superoxide dismutase, cyclooxygenase-2, caspase-1, and interleukin-1ß were significantly reduced in the treatment group. PCSK9i decreased the ratio of phosphorylated to total p38 mitogen-activated protein kinase and extracellular signal-regulated kinase in the aorta of rats with hyperglycemia. Conclusions: Short-term treatment with PCSK9i preserved endothelial function, induced vascular dilatation, and increased blood flow in the AC fistula of rats with hyperglycemia. The pleiotropic mechanisms were associated with the suppression of oxidative stress and tissue inflammation during hyperglycemia.