Biparatopic anti-PCSK9 antibody enhances the LDL-uptake in HepG2 cells.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has emerged as a promising therapeutic target to reduce lipids. In 2020, we reported a chimeric camelid-human heavy chain antibody VHH-B11-Fc targeting PCSK9. Recently, it was verified that VHH-B11 binds one linear epitope in the PCSK9 hinge region. To enhance its druggability, we have developed a novel biparatopic B11-H2-Fc Ab herein. Thereinto, surface plasmon resonance (SPR) confirmed the epitope differences in binding-PCSK9 among VHH-B11, VHH-H2 and the approved Repatha. Additionally, SPR revealed the B11-H2-Fc exhibits an avidity of approximately 0.036 nM for PCSK9, representing a considerable increase compared to VHH-B11-Fc (~ 0.69 nM). Moreover, we found the Repatha and B11-H2-Fc exhibited > 95% PCSK9 inhibition efficiency compared to approximately 48% for the VHH-Fc at 7.4 nM (P < 0.0005). Further, we verified its biological activity using the human hepatoma cells G2 model, where the B11-H2-Fc exhibited almost 100% efficiency in PCSK9 inhibition at only 0.75 µM. The immunoblotting results of low-density lipoprotein cholesterol (LDL-c) uptake assay also demonstrated the excellent performance of B11-H2-Fc on recovering the LDL-c receptor (LDLR), as strong as the Repatha (P > 0.05). These findings provide the first evidence of the efficacy of a novel Ab targeting PCSK9 in the field of lipid-lowering drugs.

Repurposing lipid-lowering drugs on asthma and lung function: evidence from a genetic association analysis.

OBJECTIVE: To explore the correlation between asthma risk and genetic variants affecting the expression or function of lipid-lowering drug targets. METHODS: We conducted Mendelian randomization (MR) analyses using variants in several genes associated with lipid-lowering medication targets: HMGCR (statin target), PCSK9 (alirocumab target), NPC1L1 (ezetimibe target), APOB (mipomersen target), ANGPTL3 (evinacumab target), PPARA (fenofibrate target), and APOC3 (volanesorsen target), as well as LDLR and LPL. Our objective was to investigate the relationship between lipid-lowering drugs and asthma through MR. Finally, we assessed the efficacy and stability of the MR analysis using the MR Egger and inverse variance weighted (IVW) methods. RESULTS: The elevated triglyceride (TG) levels associated with the APOC3, and LPL targets were found to increase asthma risk. Conversely, higher LDL-C levels driven by LDLR were found to decrease asthma risk. Additionally, LDL-C levels (driven by APOB, NPC1L1 and HMGCR targets) and TG levels (driven by the LPL target) were associated with improved lung function (FEV1/FVC). LDL-C levels driven by PCSK9 were associated with decreased lung function (FEV1/FVC). CONCLUSION: In conclusion, our findings suggest a likely causal relationship between asthma and lipid-lowering drugs. Moreover, there is compelling evidence indicating that lipid-lowering therapies could play a crucial role in the future management of asthma.

Association of lipid-lowering drugs with risk of sarcopenia: a drug target mendelian randomization study and meta-analysis.

BACKGROUND: Lipid-lowering drugs are widely used among the elderly, with some studies suggesting links to muscle-related symptoms. However, the causality remains uncertain. METHODS: Using the Mendelian randomization (MR) approach, we assessed the causal effects of genetically proxied reduced low-density lipoprotein cholesterol (LDL-C) through inhibitions of hydroxy-methyl-glutaryl-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), and Niemann-Pick C1-like 1 (NPC1L1) on sarcopenia-related traits, including low hand grip strength, appendicular lean mass, and usual walking pace. A meta-analysis was conducted to combine the causal estimates from different consortiums. RESULTS: Using LDL-C pooled data predominantly from UK Biobank, genetically proxied inhibition of HMGCR was associated with higher appendicular lean mass (beta = 0.087, P = 7.56 × 10- 5) and slower walking pace (OR = 0.918, P = 6.06 × 10- 9). In contrast, inhibition of PCSK9 may reduce appendicular lean mass (beta = -0.050, P = 1.40 × 10- 3), while inhibition of NPC1L1 showed no causal impact on sarcopenia-related traits. These results were validated using LDL-C data from Global Lipids Genetics Consortium, indicating that HMGCR inhibition may increase appendicular lean mass (beta = 0.066, P = 2.17 × 10- 3) and decelerate walking pace (OR = 0.932, P = 1.43 × 10- 6), whereas PCSK9 inhibition could decrease appendicular lean mass (beta = -0.048, P = 1.69 × 10- 6). Meta-analysis further supported the robustness of these causal associations. CONCLUSIONS: Genetically proxied HMGCR inhibition may increase muscle mass but compromise muscle function, PCSK9 inhibition could result in reduced muscle mass, while NPC1L1 inhibition is not associated with sarcopenia-related traits and this class of drugs may serve as viable alternatives to sarcopenia individuals or those at an elevated risk.

The multifaceted role of PCSK9 in cancer pathogenesis, tumor immunity, and immunotherapy.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), a well-known regulator of cholesterol metabolism and cardiovascular diseases, has recently garnered attention for its emerging involvement in cancer biology. The multifunctional nature of PCSK9 extends beyond lipid regulation and encompasses a wide range of cellular processes that can influence cancer progression. Studies have revealed that PCSK9 can modulate signaling pathways, such as PI3K/Akt, MAPK, and Wnt/ß-catenin, thereby influencing cellular proliferation, survival, and angiogenesis. Additionally, the interplay between PCSK9 and cholesterol homeostasis may impact membrane dynamics and cellular migration, further influencing tumor aggressiveness. The central role of the immune system in monitoring and controlling cancer is increasingly recognized. Recent research has demonstrated the ability of PCSK9 to modulate immune responses through interactions with immune cells and components of the tumor microenvironment. This includes effects on dendritic cell maturation, T cell activation, and cytokine production, suggesting a role in shaping antitumor immune responses. Moreover, the potential influence of PCSK9 on immune checkpoints such as PD1/PD-L1 lends an additional layer of complexity to its immunomodulatory functions. The growing interest in cancer immunotherapy has prompted exploration into the potential of targeting PCSK9 for therapeutic benefits. Preclinical studies have demonstrated synergistic effects between PCSK9 inhibitors and established immunotherapies, offering a novel avenue for combination treatments. The strategic manipulation of PCSK9 to enhance tumor immunity and improve therapeutic outcomes presents an exciting area for further investigations. Understanding the mechanisms by which PCSK9 influences cancer biology and immunity holds promise for the development of novel immunotherapeutic approaches. This review aims to provide a comprehensive analysis of the intricate connections between PCSK9, cancer pathogenesis, tumor immunity, and the potential implications for immunotherapeutic interventions.

Assessment of serum proprotein convertase subtilisin/kexin type 9 in pediatric sepsis syndrome.

Sepsis is a life-threatening condition that arises when the body's response to infection causes injury to its tissues and organs. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is an enzyme released in response to the drop in cholesterol level occurring in sepsis. Our study aimed to evaluate the prognostic role of serum Proprotein convertase subtilisin/kexin type 9 (PCSK9) level in children with sepsis and severe sepsis. Sixty children were included in this study. They were divided into two groups: 30 children in the sepsis group and 30 in the severe sepsis group. Another 30 apparently healthy children were included as a control group. Blood samples were withdrawn from all included children for complete blood count (CBC), renal function tests (RFT), liver function tests (LFT), LDL-cholesterol (LDL-C), blood culture, and serum PCSK9. In this study, PCSK9 and LDL-C were higher in the two sepsis groups than in the control group (p < 0.05). They were also higher in the severe sepsis group than the sepsis group and in the non-survivors than in the survivors (p < 0.05). PCSK9 was positively correlated with length of hospital stay in surviving children (r = 0.67, p = 0.001) and had predicted significant hematological dysfunction (adjusted B = - 96.95, p = 0.03). In conclusion, the PCSK9 assay can be used as a biomarker for bad prognosis in children suffering from clinical sepsis.

Safety and efficacy of PCSK9 inhibitor (evolocumab) in patients with non-ST segment elevation acute coronary syndrome and non-culprit artery critical lesions: a randomised controlled trial protocol (SPECIAL study).

INTRODUCTION: Patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS) and concomitant multivessel coronary artery disease (CAD) are considered patients with extremely high-risk atherosclerotic cardiovascular disease (ASCVD), and current guidelines specify a lower low-density lipoprotein cholesterol (LDL-C) target for this population. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been shown to effectively reduce LDL-C levels on a statin background. Additionally, several studies have confirmed the role of PCSK9 inhibitors in plaque regression and reducing residual cardiovascular risk in patients with ACS. However, those studies included coronary lesions with a degree of stenosis <50%. Whether the application of PCSK9 inhibitors in patients with NSTE-ACS with non-culprit artery critical lesions (stenosis degree between 50% and 75%) has a similar effect on plaque regression and improvement of cardiovascular outcomes remains unknown, with a lack of relevant research. This study aims to further investigate the safety and efficacy of evolocumab in patients with NSTE-ACS and concomitant multivessel CAD (non-culprit artery stenosis between 50% and 75%). METHODS AND ANALYSIS: In this single-centre clinical randomised controlled trial, 122 patients with NSTE-ACS and concomitant multivessel CAD (non-culprit artery stenosis between 50% and 75%) will be randomly assigned to either the evolocumab treatment group or the standard treatment group after completing culprit vessel revascularisation. The evolocumab treatment group will receive evolocumab in addition to statin therapy, while the standard treatment group will receive standard statin therapy. At baseline and week 50, patients in the evolocumab treatment group will undergo coronary angiography and OCT imaging to visualise pre-existing non-lesional vessels. The primary end point is the absolute change in average minimum fibrous cap thickness (FCT) from baseline to week 50. Secondary end points include changes in plaque lipid arc, lipid length, macrophage grading, lipid levels and major adverse cardiovascular events during the 1-year follow-up period. ETHICS AND DISSEMINATION: Ethics: this study will adhere to the principles outlined in the Helsinki Declaration and other applicable ethical guidelines. This study protocol has received approval from the Medical Research Ethics Committee of the First Affiliated Hospital of the University of Science and Technology of China (Anhui Provincial Hospital), with approval number 2022-ky214. DISSEMINATION: we plan to disseminate the findings of this study through various channels. This includes publication in peer-reviewed academic journals, presentation at relevant academic conferences and communication to the public, policymakers and healthcare professionals. We will also share updates on the research progress through social media and other online platforms to facilitate the exchange and application of scientific knowledge. Efforts will be made to ensure widespread dissemination of the research results and to have a positive impact on society. TRIAL REGISTRATION NUMBER: ChiCTR2200066675.

PCSK9 inhibitors and osteoporosis: mendelian randomization and meta-analysis.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors represent an effective strategy for reducing cardiovascular disease risk. Yet, PCSK9's impact on osteoporosis remains unclear. Hence, we employed Mendelian randomization (MR) analysis for examining PCSK9 inhibitor effects on osteoporosis. METHODS: Single nucleotide polymorphisms (SNPs) for 3-hydroxy-3-methylglutaryl cofactor A reductase (HMGCR) and PCSK9 were gathered from available online databases for European pedigrees. Four osteoporosis-related genome-wide association studies (GWAS) data served as the main outcomes, and coronary artery disease (CAD) as a positive control for drug-targeted MR analyses. The results of MR analyses examined by sensitivity analyses were incorporated into a meta-analysis for examining causality between PCSK9 and HMGCR inhibitors and osteoporosis. RESULTS: The meta-analysis involving a total of 1,263,102 subjects, showed that PCSK9 inhibitors can increase osteoporosis risk (P < 0.05, I2, 39%). However, HMGCR inhibitors are not associated with osteoporosis risk. Additionally, a replication of the analysis was conducted with another exposure-related GWAS dataset, which led to similar conclusions. CONCLUSION: PCSK9 inhibitors increase osteoporosis risk. However, HMGCR inhibitors are unremarkably linked to osteoporosis.

Causal relationship between PCSK9 inhibitor and common neurodegenerative diseases: A drug target Mendelian randomization study.

BACKGROUND: In addition to lowering cholesterol levels, the proprotein convertase subtilis kexin 9 (PCSK9) inhibitor has a variety of effects, including anti-neuroapoptosis. However, the effects of PCSK9 inhibitors on neurodegenerative diseases are controversial. Therefore, we used drug-targeted Mendelian randomization (MR) analysis to investigate the effects of PCSK9 inhibitors on different neurodegenerative diseases. METHODS: We collected single nucleotide polymorphisms (SNPs) of PCSK9 from published statistics of genome-wide association studies and performed drug target MR analyses to detect a causal relationship between PCSK9 inhibitors and the risk of neurodegenerative diseases. We utilized the effects of 3-Hydroxy -3- methylglutaryl-assisted enzyme A reductase (HMGCR) inhibitors (statin targets) for comparison with PCSK9 inhibitors. Coronary heart disease risk was used as a positive control, and primary outcomes included amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Alzheimer's disease (AD). RESULTS: PCSK9 inhibitors marginally reduced the risk of ALS (OR [95%] = 0.89 [0.77 to 1.00], p = 0.048), while they increased the risk of PD (OR [95%] = 1.417 [1.178 to 1.657], p = 0.004). However, HMGCR inhibitors increased the risk of PD (OR [95%] = 1.907 [1.502 to 2.312], p = 0.001). CONCLUSION: PCSK9 inhibitors significantly reduce the risk of ALS but increase the risk of PD. HMGCR inhibitors may be the risk factor for PD.

Effects of genetically proxied lipid-lowering drugs on acute myocardial infarction: a drug-target mendelian randomization study.

OBJECTIVE: High low-density-lipoprotein (LDL) cholesterol has been associated with an increased risk of coronary artery diseases (CAD) including acute myocardial infarction (AMI). However, whether lipids lowering drug treatment is causally associated with decreased risk of AMI remains largely unknown. We used Mendelian randomization (MR) to evaluate the influence of genetic variation affecting the function of lipid-lowering drug targets on AMI. METHODS: Single-nucleotide polymorphisms (SNPs) associated with lipids as instruments were extracted from the Global Lipids Genetics Consortium (GLGC). The genome-wide association study (GWAS) data for AMI were obtained from UK Biobank. Two sample MR analysis was used to study the associations between high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides (TG) with AMI (n = 3,927). Genetic variants associated with LDL cholesterol at or near drug target gene were used to mimic drug effects on the AMI events in drug target MR. RESULTS: Genetically predicted higher LDL-C (per one SD increase in LDL-C of 38.67 mg/dL, OR 1.006, 95% CI 1.004-1.007) and TG (per one SD increase in TG of 90.72 mg/dL, 1.004, 1.002-1.006) was associated with increased risk of AMI, but decreased risk for higher HDL-C (per one SD increase in HDL-C of 15.51 mg/dL, 0.997, 0.995-0.999) in univariable MR. Association remained significant for LDL-C, but attenuated toward the null for HDL-C and TG in multivariable MR. Genetically proxied lower LDL-C with genetic variants at or near the PCSK9 region (drug target of evolocumab) and NPC1L1 (drug target of ezetimibe) were associated with decreased risk of AMI (0.997, 0.994-0.999 and 0.986, 0.975-0.998, respectively), whereas genetic variants at HMGCR region (drug target of statin) showed marginal association with AMI (0.995, 0.990-1.000). After excluding drug target-related SNPs, LDL-C related SNPs outside the drug target region remained a causal effect on AMI (0.994, 0.993-0.996). CONCLUSIONS: The findings suggest that genetically predicted LDL-C may play a predominant role in the development of AMI. The drug MR results imply that ezetimibe and evolocumab may decrease the risk of AMI due to their LDL-C lowering effect, and there are other non-drug related lipid lowering pathways that may be causally linked to AMI.

Associations of lipids and lipid-modifying drug target genes with atrial fibrillation risk based on genomic data.

BACKGROUND: The causal associations of lipids and the drug target genes with atrial fibrillation (AF) risk remain obscure. We aimed to investigate the causal associations using genetic evidence. METHODS: Mendelian randomization (MR) analyses were conducted using summary-level genome-wide association studies (GWASs) in European and East Asian populations. Lipid profiles (low-density lipoprotein cholesterol, triglyceride, and lipoprotein[a]) and lipid-modifying drug target genes (3-hydroxy-3-methylglutaryl-CoA reductase, proprotein convertase subtilisin/kexin type 9, NPC1-like intracellular cholesterol transporter 1, apolipoprotein C3, angiopoietin-like 3, and lipoprotein[a]) were used as exposures. AF was used as an outcome. The inverse variance weighted method was applied as the primary method. Summary-data-based Mendelian randomization analyses were performed for further validation using expression quantitative trait loci data. Mediation analyses were conducted to explore the indirect effect of coronary heart disease. RESULTS: In the European population, MR analyses demonstrated that elevated levels of lipoprotein(a) increased AF risk. Moreover, analyses focusing on drug targets revealed that the genetically proxied target gene LPA, which simulates the effects of drug intervention by reducing lipoprotein(a), exhibited an association with AF risk. This association was validated in independent datasets. There were no consistent and significant associations observed for other traits when analyzed in different datasets. This finding was also corroborated by Summary-data-based Mendelian randomization analyses between LPA and AF. Mediation analyses revealed that coronary heart disease plays a mediating role in this association. However, in the East Asian population, no statistically significant evidence was observed to support these associations. CONCLUSIONS: This study provided genetic evidence that Lp(a) may be a causal factor for AF and that LPA may represent a promising pharmacological target for preventing AF in the European population.

Quantitative assessment of baseline imbalances in evolocumab and alirocumab trials: a meta-epidemiological study.

BACKGROUND: Baseline imbalances have been identified in randomized trials of evolocumab and alirocumab. Our aim was to quantitatively assess (1) the presence of systematic baseline differences, and (2) the relationship of baseline differences with effects on low-density lipoprotein-cholesterol (LDL-c) and clinical outcomes in the trials. METHODS: We performed a meta-epidemiological study. PubMed, Embase, regulatory reports, ClinicalTrials.gov and company websites were searched for trials. Seven baseline characteristics (mean age, LDL-c, BMI, percentage males, diabetics, smokers, and hypertensives) and five outcomes (LDL-c, major adverse cardiac events, serious adverse events, any adverse events, all-cause mortality) were extracted. We calculated (1) range and distribution of baseline imbalances (sign-test), (2) pooled baseline differences and heterogeneity (meta-analysis), (3) differences in SDs around continuous variables (sign-test and pooling), and (4) the relationship of baseline differences with outcomes (meta-regression). The comparisons of PCSK9-inhibitor groups with either placebo or ezetimibe were analysed separately and combined. RESULTS: We identified 43 trials with 63,193 participants. Baseline characteristics were frequently missing. Many trials showed small baseline imbalances, but some large imbalances. Only baseline BMI showed a statistically significant lower pooled mean for the drug versus placebo groups (MD -0.16; 95% CI -0.24 to -0.09). Heterogeneity in baseline imbalances was present in six placebo- and five ezetimibe-comparisons. Heterogeneity was statistically significant for BMI, males, diabetics and hypertensives in the combined comparisons. There was a statistically significant preponderance for larger SDs in the PCSK9-inhibitor versus control groups (sign-test age 0.014; LDL-c 0.014; BMI 0.049). Meta-regression showed clinically relevant relationships of baseline imbalances in age, BMI and diabetics with the risk of any adverse events and the risk of mortality. Two relationships were statistically significant: A higher mean BMI in the drug versus control group with a decreased risk of mortality (beta - 0.56; 95% CI -1.10 to -0.02), and a higher proportion of diabetics with an increased risk of any adverse events (beta 0.02; 95% 0.01 to 0.04). CONCLUSIONS: Heterogeneous baseline imbalances and systematically different SDs were present in evolocumab and alirocumab trials, so study groups cannot be assumed to be comparable. These findings raise concerns about the design and conduct of the randomization procedures.

[Pharmacological and clinical profile of inclisiran sodium, a long-acting LDL cholesterol lowering siRNA, LEQVIO for s.c. injection syringe 300†|mg].

Inclisiran sodium (Brand name: LEQVIO® for s.c. injection syringe 300 |mg, hereinafter referred to as inclisiran), a small interfering ribonucleic acid (siRNA) product that targets the mRNA that encodes the proprotein convertase subtilisin/kexin type 9 (PCSK9) protein was approved on September 25, 2023 for the indication of "Familial hypercholesterolemia, hypercholesterolemia" in Japan. Inclisiran is conjugated on the sense strand with triantennary N-acetylgalactosamine to facilitate uptake by hepatocytes. In vitro and in vivo pharmacology studies demonstrated the lowering effects of PCSK9 and LDL-C in hepatocytes and cynomolgus monkeys. It was considered unlikely to cause clinically significant risks due to toxicities arising from complementary binding to non-target RNA sequences (hybridization-dependent off-target effects). Clinical trials conducted globally including Japan in patients with familial hypercholesterolemia and hypercholesterolemia who did not reach the LDL-C target showed that inclisiran sodium 300 |mg dosed at Day 1, Day 90 and then every 6 months demonstrated significant LDL-C reduction and the efficacy sustained long. The majority of patients achieved the guideline recommended LDL-C targets. Inclisiran sodium 300 |mg was well tolerated and there were no specific safety concerns. Therefore, inclisiran is expected to be a new therapeutic option for the patients with familial hypercholesterolemia and hypercholesterolemia.

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.

Role of CETP, PCSK-9, and CYP7-alpha in cholesterol metabolism: Potential targets for natural products in managing hypercholesterolemia.

Cardiovascular diseases (CVDs) are a leading cause of mortality worldwide, primarily affecting the heart and blood vessels, with atherosclerosis being a major contributing factor to their onset. Epidemiological and clinical studies have linked high levels of low-density lipoprotein (LDL) emanating from distorted cholesterol homeostasis as its major predisposing factor. Cholesterol homeostasis, which involves maintaining the balance in body cholesterol level, is mediated by several proteins or receptors, transcription factors, and even genes, regulating cholesterol influx (through dietary intake or de novo synthesis) and efflux (by their conversion to bile acids). Previous knowledge about CVDs management has evolved around modulating these receptors' activities through synthetic small molecules/antibodies, with limited interest in natural products. The central roles of the cholesteryl ester transfer protein (CETP), proprotein convertase subtilisin/kexin type 9 (PCSK9), and cytochrome P450 family 7 subfamily A member 1 (CYP7A1), among other proteins or receptors, have fostered growing scientific interests in understanding more on their regulatory activities and potential as drug targets. We present up-to-date knowledge on the contributions of CETP, PCSK9, and CYP7A1 toward CVDs, highlighting the clinical successes and failures of small molecules/antibodies to modulate their activities. In recommendation for a new direction to improve cardiovascular health, we have presented recent findings on natural products (including functional food, plant extracts, phytochemicals, bioactive peptides, and therapeutic carbohydrates) that also modulate the activities of CETP, PCSK-9, and CYP7A1, and emphasized the need for more research efforts redirected toward unraveling more on natural products potentials even at clinical trial level for CVD management.

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.

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.

20( S )-Protopanaxatriol Improves Atherosclerosis by Inhibiting Low-Density Lipoprotein Receptor Degradation in ApoE KO Mice.

ABSTRACT: Atherosclerosis (AS) is a chronic progressive disease caused by various factors and causes various cerebrovascular and cardiovascular diseases (CVDs). Reducing the plasma levels of low-density lipoprotein cholesterol is the primary goal in preventing and treating AS. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a crucial role in regulating low-density lipoprotein cholesterol metabolism. Panax notoginseng has potent lipid-reducing effects and protects against CVDs, and its saponins induce vascular dilatation, inhibit thrombus formation, and are used in treating CVDs. However, the anti-AS effect of the secondary metabolite, 20( S )-protopanaxatriol (20( S )-PPT), remains unclear. In this study, the anti-AS effect and molecular mechanism of 20( S )-PPT were investigated in vivo and in vitro by Western blotting, real-time polymerase chain reaction, enzyme-linked immunosorbent assay, immunofluorescence staining, and other assays. The in vitro experiments revealed that 20( S )-PPT reduced the levels of PCSK9 in the supernatant of HepG2 cells, upregulated low-density lipoprotein receptor protein levels, promoted low-density lipoprotein uptake by HepG2 cells, and reduced PCSK9 mRNA transcription by upregulating the levels of forkhead box O3 protein and mRNA and decreasing the levels of HNF1α and SREBP2 protein and mRNA. The in vivo experiments revealed that 20( S )-PPT upregulated aortic α-smooth muscle actin expression, increased the stability of atherosclerotic plaques, and reduced aortic plaque formation induced by a high-cholesterol diet in ApoE -/- mice (high-cholesterol diet-fed group). Additionally, 20( S )-PPT reduced the aortic expression of CD68, reduced inflammation in the aortic root, and alleviated the hepatic lesions in the high-cholesterol diet-fed group. The study revealed that 20( S )-PPT inhibited low-density lipoprotein receptor degradation via PCSK9 to alleviate AS.

Postmarketing Reports of Incomplete Dosing-Related Complications with Self-Injected PCSK9 Inhibitors: A Descriptive Study and Disproportionality Analysis.

BACKGROUND: Evolocumab and alirocumab are self-injected proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors indicated for low-density lipoprotein cholesterol reduction. Complications in the use or functionality of self-injection devices may precipitate incomplete dosing. OBJECTIVE: This study sought to characterize postmarketing dosing failure reports involving self-injected PCSK9 inhibitors. METHODS: US Food and Drug Administration Adverse Event Reporting System (FAERS) [2016-second quarter of 2023] data were utilized for a disproportionality analysis. Eight self-injected comparator medications served as referents. Medical Dictionary for Regulatory Activities preferred terms indicating explicit or probable failure to administer a complete dose classified cases. Proportional reporting ratios (PRRs) > 2.0 and lower 95% confidence intervals (CIs) > 1.0 indicated disproportionality signals. US FDA Manufacturer and User Facility Device Experience (MAUDE) [2013-2023] data underwent a narrative review. RESULTS: During the study period, 194,781 (evolocumab, n = 152,831; alirocumab, n = 41,950) drug-event pairs and 43,725 (evolocumab, n = 38,489; alirocumab, n = 5236) cases reported to FAERS identified PCSK9 inhibitors. MAUDE contained six evolocumab reports, half describing dose omission, and no alirocumab reports. A potential dosing failure signal was detected for evolocumab (PRR 2.01; 95% CI 1.98-2.03), but not alirocumab (PRR 0.99; 95% CI 0.97-1.02), relative to pooled comparator reports. Across three case term subcategories, incomplete dosing disproportionality signals were further identified for evolocumab patient usage complication terms (PRR 3.44; 95% CI 3.38-3.50) and alirocumab device malfunction terms (PRR 2.09; 95% CI 1.98-2.22). CONCLUSIONS: Proprotein convertase subtilisin kexin type 9 inhibitor incomplete dosing-related complications are frequently reported in the postmarketing setting. Systematic efforts to understand the incidence and mechanisms of dosing failure and associated patient burdens are needed.