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Proprotein convertase substilin/kexin type 9 (PCSK9), a pivotal protein regulating lipid metabolism, has been implicated in promoting microthrombotic formation and inflammatory cascades, thereby contributing to cardiovascular ischemia/reperfusion (I/R) injury. However, its involvement in cerebral I/R injury and its potential role in microcirculation protection remain unexplored. In this investigation, we utilized a middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model to simulate ischemic stroke. Different concentrations of evolocumab (1, 5, 10 mg/kg, i.v.), a PCSK9 inhibitor, were administered to assess its impact. Immunofluorescence staining was employed to analyze changes in the expression of occludin, claudin-5, thrombocyte, ICAM-1, VCAM-1, and CD45, providing insights into blood-brain barrier integrity, platelet adhesion, and immune cell infiltration. Moreover, the Morris water maze and elevated plus maze were utilized to evaluate neurological and behavioral functions in MCAO/R mice, shedding light on the effects of PCSK9 inhibition. Our findings revealed a surge in plasma PCSK9 levels post-MCAO/R, peaking at 24 h post-reperfusion. Evolocumab (10 mg/kg) treatment significantly mitigated brain infarction and neurological deficits, evidenced by enhanced locomotor function and reduced post-stroke anxiety. However, it did not ameliorate cognitive impairment following MCAO/R. Additionally, evolocumab administration led to diminished leakage of evans blue solution and upregulated expression of occludin and claudin-5. Thrombocyte, ICAM-1, VCAM-1, and CD45 levels were notably reduced in the penumbral area post-evolocumab treatment. These protective effects are speculated to be mediated through the inhibition of the ERK/NF-κB pathway. The PCSK9 inhibitor evolocumab holds promise as a therapeutic agent during the acute phase of stroke, exerting its beneficial effects by modulating the ERK/NF-κB signaling pathway., Competing Interests: Declarations Competing Interests The authors declare no competing interests. Ethics Approval This study was performed in accordance with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Nanjing Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University (Date 2022-03-07/No. 2022DZGKJDWLS-0043). Consent to Participate Not applicable. Consent to Publish Not applicable., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Clinical implementation of therapeutic genome editing relies on efficient in vivo delivery and the safety of CRISPR-Cas tools. Previously, we identified PsCas9 as a Type II-B family enzyme capable of editing mouse liver genome upon adenoviral delivery without detectable off-targets and reduced chromosomal translocations. Yet, its efficacy remains insufficient with non-viral delivery, a common challenge for many Cas9 orthologues. Here, we sought to redesign PsCas9 for in vivo editing using lipid nanoparticles. We solve the PsCas9 ribonucleoprotein structure with cryo-EM and characterize it biochemically, providing a basis for its rational engineering. Screening over numerous guide RNA and protein variants lead us to develop engineered PsCas9 (ePsCas9) with up to 20-fold increased activity across various targets and preserved safety advantages. We apply the same design principles to boost the activity of FnCas9, an enzyme phylogenetically relevant to PsCas9. Remarkably, a single administration of mRNA encoding ePsCas9 and its guide formulated with lipid nanoparticles results in high levels of editing in the Pcsk9 gene in mouse liver, a clinically relevant target for hypercholesterolemia treatment. Collectively, our findings introduce ePsCas9 as a highly efficient, and precise tool for therapeutic genome editing, in addition to the engineering strategy applicable to other Cas9 orthologues., (© 2024. The Author(s).)

Proprotein convertase subtilisin/kexin type 9 (PCSK9) increases plasma low-density lipoprotein-cholesterol (LDL-C) by decreasing the expression of the LDL-receptor on hepatic cells. Ongericimab (JS002) is a novel PCSK9 monoclonal antibody that exhibits a long-acting LDL-C lowering effect by exclusively inhibiting PCSK9 in pre-clinical studies. Two randomized, double-blind, placebo-controlled trials were conducted to evaluate the safety, tolerability, efficacy, immunogenicity, pharmacokinetic, and pharmacodynamic profiles of ongericimab in healthy subjects and patients with hypercholesterolemia. Eighty-four healthy subjects in the phase Ia study received a single dose of placebo or ongericimab (15-450 mg). Ninety patients with hypercholesterolemia in the phase Ib/II study received placebo or ongericimab 150 mg Q2W, 300 mg Q4W, or 450 mg Q4W for 12 weeks. Ongericimab exhibited non-linear kinetics. The apparent clearance decreased as the dosage increased, with terminal elimination half-life (t 1/2 ) values of 4.5-6.5 days. Overall, ongericimab was well tolerated in both studies. A single dose of ongericimab reduced LDL-C levels by 30%-73% in healthy subjects, and repeated doses of ongericimab reduced LDL-C levels by 67%-80% in patients with hypercholesterolemia. At the end of the dosing interval in the phase Ib/II study, over 70% of patients' LDL-C levels decreased by more than 50% from baseline. The results showed that ongericimab had a significant long-acting LDL-C lowering effect with good safety and potential for clinical application., (© 2024 The Author(s). Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Coronary artery disease (CAD) causes myocardial ischemia, narrowing or occlusion of the lumen. Although great progress has been made in the treatment of CAD, the existing treatment methods do not meet the clinical needs, so it is urgent to find new treatment methods. The aim of this study was to investigate the mechanism of action of miR-148a-3p in alleviating CAD by inhibiting vascular endothelial cell injury and to provide new ideas for the treatment of CAD. A cell model was constructed by lipopolysaccharide (LPS) induction of vascular endothelial cells, and a CAD rat model was established by a high-fat diet and intraperitoneal injection of posterior pituitary hormone. Relevant indices were detected by RT-qPCR, ELISA, Western blot, MTT, and flow cytometry. The results indicate that in LPS-induced vascular endothelial cell assays, miR-148a-3p inhibited the upregulation of PCSK9, thereby suppressing the NF-κB signaling pathway and promoting vascular endothelial cell proliferation. Overexpression of PCSK9 and the addition of NF-κB signaling pathway activator increased vascular endothelial cell apoptosis. In animal experiments, miR-148a-3p alleviated the symptoms of CAD rats, whereas overexpression of PCSK9 promoted apoptosis and increased atheromatous plaque area in CAD rats. In conclusion, miR-148a-3p inhibits the NF-κB signaling pathway through downregulation of PCSK9, thereby protecting vascular endothelial cells and alleviating CAD., (© 2024 Wiley Periodicals LLC.)

The present study intended to divulge the potential role of garlic-derived organosulfur compounds (OSCs) in targeting PCSK-9 and averting its interaction with the EGF-A portion of LDL-R via in-vitro and in-silico analysis. Our in-silico screening data showed that 3-(Propylsulfinyl)-L-alanine (PSA), S -Ethyl-L-cysteine (SEC), alliin, and S -Allyl-L-cysteine (SAC) exhibited higher binding energy (-7.05, -7.00, -6.65, and -6.31 Kcal/mol, respectively) against PCSK-9, among other selected OSCs. Further, the protein-protein interaction study of PCSK-9-OSCs-complex with EGF-A demonstrated a similar binding pattern with E-total values ranging from -430.01 to -405.6 Kcal/mol. These results were further validated via in-vitro analysis which showed that SEC, SAC, and diallyl trisulphide (DAT) exhibited the lowest IC 50 values of 4.70, 5.26, and 5.29 µg/mL, respectively. In conclusion, the presented data illustrated that SEC, SAC, and DAT were the best inhibitors of PCSK-9 activity and may have the potential to improve the LDL-R function and lower the circulatory LDL-C level.

Objective: Disorders of lipid oxidation play an important role in organ damage, and lipid metabolites are associated with inflammation and coagulation dysfunction in sepsis. However, the specific molecular mechanism by which lipid metabolism-related proteins regulate sepsis is still unclear. The aim of this study is to investigate the role of mortality factor 4-like protein 1 (MORF4L1, also called MRG15), a hepatic lipid metabolism related gene, in sepsis-induced liver injury., Methods: In the mouse sepsis models established by cecal ligation and puncture (CLP) and lipopolysaccharide (LPS), the impact of pretreatment with the MRG15 inhibitor argatroban on sepsis-related liver injury was investigated. In the LPS-induced hepatocyte sepsis cell model, the effects of MRG15 overexpression or knockdown on hepatic inflammation and lipid metabolism were studied. Additionally, in a co-culture system of hepatocytes and macrophages, the influence of MRG15 knockdown in hepatocytes on the synthesis and secretion of inflammation-related protein PCSK9 as well as its effect on macrophage activation were examined., Results: Studies have shown that MRG15 expression was increased in septicemia mice and positively correlated with lipid metabolism and inflammation. However, knockdown of MRG15 ameliorates sepsis-induced hepatocyte injury. Increased MRG15 in LPS-stimulated hepatocytes promotes PCSK9 synthesis and secretion, which induces macrophage M1 polarization and exacerbates the inflammatory response. Agatroban, an inhibitor of MRG15, ameliorates sepsis-induced liver injury in mice by inhibiting MRG15-induced lipid metabolism disorders and inflammatory responses., Conclusions: In sepsis, increased MRG15 expression in hepatocytes leads to disturbed hepatic lipid metabolism and induces macrophage M1 polarization by secreting PCSK9, ultimately exacerbating liver injury., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Aims: The association and co-isolation of low-density lipoproteins (LDL) and extracellular vesicles (EVs) have been shown in blood plasma. Here we explore this relationship to better understand the role of EVs in atherogenesis., Methods and Results: Wild type (WT), PCSK9 -/- , and LDLR -/- C57BL/6 mice were used in this study. Eleven week-old male mice were fed high-fat diet (HFD) for 12 weeks or kept on normal diet until old age (22-months). Cardiac function was assessed by ultrasound, cholesterol was quantified with a colorimetric kit and circulating EVs were measured using flow cytometry. Plaques were analysed post-mortem using Oil-Red-O staining of the aortic arch. EVs were measured from platelet free blood plasma samples of normal and hypercholesterolaemic clinical patients. Based on annexin V and CD63 staining, we found a significant increase in EV levels in LDLR -/- and PCSK9 -/- mice after HFD, but CD81 showed no significant change in either group. There was no significant change in plaque formation after HFD. PCSK9 -/- mice show a favourable cardiac function after HFD. Blood cholesterol levels progressively increased during HFD, with LDLR -/- mice showing high levels while PCSK9 -/- were significantly lowered compared to WT animals. In mice at old age, similar cholesterol levels were observed as in young mice. In old age, LDLR -/- mice showed significantly increased plaques. At old age, ejection fraction was decreased in all groups of mice, as were CD63 + EVs. Similarly to mice, in patients with hypercholesterolaemia, CD63 + EVs were significantly depleted., Conclusions: This research demonstrates an inverse relationship between circulating EVs and cholesterol, making EVs a potential marker for cardiovascular disease (CVD). HFD causes reduced cardiac function, but atherosclerotic development is slowly progressing in hypercholesterolaemic models and only observed with old animals. These results also bring further evidence for the benefit of using of PCSK9 inhibitors as therapeutic agents in CVD., (© 2024. The Author(s).)

Cytidine base editors (CBEs) hold significant potential in genetic disease treatment and in breeding superior traits into animals. However, their large protein sizes limit their delivery by adeno-associated virus (AAV), given its packing capacity of <4.7 kb. To overcome this, we employed a web-based fast generic discovery (WFG) strategy, identifying several small ssDNA deaminases (Sdds) and constructing multiple Sdd-CBE 1.0 versions. SflSdd-CBE 1.0 demonstrated high C-to-T editing efficiency, comparable to AncBE4max, while SviSdd-CBE 1.0 exhibited moderate C-to-T editing efficiency with a narrow editing window (C3 to C5). Utilizing AlphaFold2, we devised a one-step miniaturization strategy, reducing the size of Sdds while preserving their efficiency. Notably, we administered AAV8 expressing PCSK9 targeted sgRNA and SflSdd-CBEs (nSaCas9) 2.0 into mice, leading to gene-editing events (with editing efficiency up to 15%) and reduced serum cholesterol levels, underscoring the potential of Sdds in gene therapy. These findings offer new single-stranded editing tools for the treatment of rare genetic diseases., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

The inhibitor-kappaB kinase epsilon (IKKε) represents a non-canonical IκB kinase that modulates NF-κB activity and interferon I responses. Inhibition of this pathway has been linked with atherosclerosis and metabolic dysfunction-associated steatotic liver disease (MASLD), yet the results are contradictory. In this study, we employed a combined model of hepatic PCSK9 D377Y overexpression and a high-fat diet for 16 weeks to induce atherosclerosis and liver steatosis. The development of atherosclerotic plaques, serum lipid concentrations, and lipid metabolism in the liver and adipose tissue were compared between wild-type and IKKε knock-out mice. The formation and progression of plaques were markedly reduced in IKKε knockout mice, accompanied by reduced serum cholesterol levels, fat deposition, and macrophage infiltration within the plaque. Additionally, the development of a fatty liver was diminished in these mice, which may be attributed to decreased levels of multiple lipid species, particularly monounsaturated fatty acids, triglycerides, and ceramides in the serum. The modulation of several proteins within the liver and adipose tissue suggests that de novo lipogenesis and the inflammatory response are suppressed as a consequence of IKKε inhibition. In conclusion, our data suggest that the knockout of IKKε is involved in mechanisms of both atherosclerosis and MASLD. Inhibition of this pathway may therefore represent a novel approach to the treatment of cardiovascular and metabolic diseases.

Excessive caloric intake and obesity due to high-fat (HFD) and high-disaccharide (HDD) diets have been recognized as major contributing factors to dyslipidemia and metabolic dysfunction-associated steatotic liver disease (MASLD). However, the effect of HFD and HDD without excessive caloric intake is obscure. The aim of the study was to evaluate the effect of physiological caloric intake delivered through HFD and HDD on liver and lipid profiles. The study was performed on 6-week-old male and female (50/50%) Sprague Dawley rats, receiving either a standard (controls, n = 16), HFD (n = 14) or HDD (n = 14) chow. All groups received the same, standard daily calorie rations, titrated weekly to the age of growing rats, for 12 weeks. A panel of metabolic in vivo measurement were performed, followed by histological, biochemical and molecular biology assays on tissues harvested from sacrificed rats. There was no significant difference between the groups in body weight. In contrast to controls, HFD and HDD groups showed metabolic dysfunction-associated steatohepatitis (MASH) characterized by liver steatosis, inflammation, ballooning of hepatocytes and fibrosis. These changes were more pronounced in the HFD than in the HDD group. The HFD group showed significantly higher serum LDL than controls or HDD rats. Furthermore, the HFD group had higher liver protein levels of low-density lipoprotein receptor (LDLR) but lower plasma levels of proprotein convertase subtilisin/kexin type 9 (PCSK9) than the controls or HDD group. There were no differences between sexes in evaluated parameters. The excessive caloric intake and obesity are not prerequisites for the development of MASH and dyslipidemia in rats. The liver changes induced by the HFD and HDD diets exhibit differences in severity, as well as in the expression patterns of LDLR and PCSK9. Notably, these effects are independent of the sex of the rats., (© 2024. The Author(s).)

Background: The intricate biological mechanism underlying lung adenocarcinoma (LUAD), characterized by a deficiency of distinctive biomarkers, remain elusive. The presence of Long non-coding RNAs (lncRNAs) have been established to play a role in carcinogenesis. Nevertheless, the regulatory effects and mechanisms of lncRNA CYTOR in LUAD have yet to be elucidated., Methods: In this study, RT-qPCR and Western blot were adopted to examine gene mRNA and protein expression, respectively. Cell proliferation was evaluated by CCK-8 assays. Transwell was performed to assay cell migration and invasion. The function of CYTOR in vivo was investigated through a xenograft animal model., Results: We observed an apparent upregulation of CYTOR in LUAD. Silencing CYTOR significantly reduced proliferation, migration, and invasion capabilities of LUAD cells. Mechanism analysis indicated that CYTOR targeted the miR-503-5p/PCSK9 axis. Additionally, inhibiting of miR-503-5p partially reversed the inhibitory effects of CYTOR silencing on the malignant progression of LUAD cells. Animal experiments revealed that CYTOR/miR-503-5p/PCSK9 curbed tumor formation of nude mice in vivo., Conclusion: These findings demonstrated that lncRNA CYTOR acted as an oncogene in LUAD, regulating tumor malignant progression through the miR-503-5p/PCSK9 axis. This study unveiled a new regulation mechanism of LUAD progression, offering potential therapeutic targets for LUAD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Dysregulated cholesterol metabolism is a hallmark of atherosclerotic cardiovascular diseases, yet our understanding of how endogenous cholesterol synthesis affects atherosclerosis is not clear. The energy sensor AMP-activated protein kinase (AMPK) phosphorylates and inhibits the rate-limiting enzyme in the mevalonate pathway HMG-CoA reductase (HMGCR). Recent work demonstrated that when AMPK-HMGCR signaling was compromised in an Apoe -/- model of hypercholesterolemia, atherosclerosis was exacerbated due to elevated hematopoietic stem and progenitor cell mobilization and myelopoiesis. We sought to validate the significance of the AMPK-HMGCR signaling axis in atherosclerosis using a non-germline hypercholesterolemia model with functional ApoE., Methods: Male and female HMGCR S871A knock-in (KI) mice and wild-type (WT) littermate controls were made atherosclerotic by intravenous injection of a gain-of-function Pcsk9 D374Y -adeno-associated virus followed by high-fat and high-cholesterol atherogenic western diet feeding for 16 weeks., Results: AMPK activation suppressed endogenous cholesterol synthesis in primary bone marrow-derived macrophages from WT but not HMGCR KI mice, without changing other parameters of cholesterol regulation. Atherosclerotic plaque area was unchanged between WT and HMGCR KI mice, independent of sex. Correspondingly, there were no phenotypic differences observed in hematopoietic progenitors or differentiated immune cells in the bone marrow, blood, or spleen, and no significant changes in systemic markers of inflammation. When lethally irradiated female mice were transplanted with KI bone marrow, there was similar plaque content relative to WT., Conclusions: Given previous work, our study demonstrates the importance of preclinical atherosclerosis model comparison and brings into question the importance of AMPK-mediated control of cholesterol synthesis in atherosclerosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Purpose of Review: Although the clinical benefit of reducing low-density lipoprotein cholesterol (LDLc) in patients with coronary artery disease (CAD) is well-established, the impact on plaque composition and stability is less clear. Our narrative review aimed to assess the clinical effects of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors on coronary plaque characteristics specifically focusing from atheroma progression to regression and stabilization., Recent Findings: The combination of statin therapy and PCSK9 inhibitors (evolocumab and alirocumab) promotes plaque stability in patients following an acute coronary syndrome. The GLAGOV study highlighted the relationship between achieved LDLc levels and changes in percentage atheroma volume. Similarly, the PACMAN-AMI study concluded that the qualitative and quantitative changes in coronary plaque were associated with the levels of LDLc. Assessing the severity of coronary artery stenosis and the extent of atherosclerotic burden by means of imaging techniques (e.g., IVUS, OCT and near-infrared spectroscopic) have significantly advanced our understanding of the benefits from promoting plaque regression and achieving to features of plaque stabilization through increasingly intensive lipid-lowering strategies., (© 2024. The Author(s).)

Background: To date, PCSK9 inhibitors are well known for eliminating cardiac and cerebral artery ischemia events by lowering the serum lipid level. However, the pathophysiological value of in-plaque PCSK9 expression is still unclear., Methods: Advanced plaques removed by carotid endarterectomy were sectioned and stained to identify the PCSK9 expression pattern and its co-expression with rupture-relevant markers. To investigate the correlation of PCSK9 expression with regional blood shear flow, hemodynamic characteristics were analyzed using computational fluid dynamics, and representative parameters were compared between PCSK9 positive and negative staining plaques. To explore this phenomenon in vitro, human aortic vascular smooth muscle cells were used to overexpress and knock down PCSK9. The impacts of PCSK9 modulations on mechanical sensor activity were testified by western blot and immunofluorescence. Real-time polymerase chain reaction was used to evaluate the transcription levels of downstream rupture-prone effectors., Results: PCSK9 distribution in plaque preferred cap and shoulder regions, residing predominantly in smooth muscle actin-positive cells. Cap PCSK9 expression correlated with fibrous cap thickness negatively and co-expressed with MMP-9, both pointing to the direction of plaque rupture. A hemodynamic profile indicated a rupture-prone feature of cap PCSK9 expression. In vitro, overexpression and knockdown of PCSK9 in human aortic vascular smooth muscle cells has positive modulation on mechanical sensor Yes-associated protein 1 (YAP) activity and transcription levels of its downstream rupture-prone effectors. Serial section staining verified in situ colocalization among PCSK9, YAP, and downstream effectors., Conclusions: Cap PCSK9 possesses a biomarker for rupture risk, and its modulation may lead to a novel biomechanical angle for plaque interventions., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose of Review: There are no current drug therapies to limit abdominal aortic aneurysm (AAA) growth. This review summarizes evidence suggesting that inhibiting proprotein convertase subtilisin/kexin type 9 (PCSK9) may be a drug target to limit AAA growth., Recent Findings: Mendelian randomization studies suggest that raised LDL and non-HDL-cholesterol are causal in AAA formation. PCSK9 was reported to be upregulated in human AAA samples compared to aortic samples from organ donors. PCSK9 gain of function viral vectors promoted aortic expansion in C57BL/6 mice infused with angiotensin II. The effect of altering PCSK9 expression in the aortic perfusion elastase model was reported to be inconsistent. Mutations in the gene encoding PCSK9, which increase serum cholesterol, were associated with increased risk of human AAA. Patients with AAA also have a high risk of cardiovascular death, myocardial infarction and stroke. Recent research suggests that PCSK9 inhibition would substantially reduce the risk of these events., Summary: Past research suggests that drugs that inhibit PCSK9 have potential as a novel therapy for AAA to both limit aneurysm growth and reduce risk of cardiovascular events. A large multinational randomized controlled trial is needed to test if PCSK9 inhibition limits AAA growth and cardiovascular events., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

From the Cynanchum wilfordii roots, 32 compounds, including 5 previously undescribed (1, 4-6, 12) and 27 known (2, 3, 7-11, 13-32) compounds, were isolated, and their structures were elucidated using NMR spectroscopic data and MS data aided by ECD calculations or the modified Mosher's reaction. All isolates were tested for their inhibitory effects on proprotein convertase subtilisin/kexin type 9 (PCSK9) secretion. Among the isolates, compound 4, a methyl cholesterol analog, exhibited the most potent effect in reducing PCSK9 secretion, along with PCSK9 downregulation at the mRNA and protein levels via FOXO1/3 upregulation. Moreover, compound 4 attenuated statin-induced PCSK9 expression and enhanced the uptake of DiI-LDL low-density lipoprotein. Thus, compound 4 is suggested to be a potential candidate for controlling cholesterol levels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) is primarily recognized for its role in lipid metabolism, but recent evidence suggests that it may have broader implications due to its diverse tissue expression., Objective: This review aims to explore the multifaceted functions of PCSK9, highlighting its pro-atherosclerotic effects, including its impact on circulating lipoprotein variables, non-low-density lipoprotein receptors, and various cell types involved in atherosclerotic plaque development., Conclusions: PCSK9 exhibits diverse roles beyond lipid metabolism, potentially contributing to atherosclerosis through multiple pathways. Understanding these mechanisms could offer new insights into therapeutic strategies targeting PCSK9 for cardiovascular disease management., (© 2024 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the epidermal growth factor precursor homologous domain A (EGF-A) of low-density lipoprotein receptor (LDLR) in the liver and triggers the degradation of LDLR via the lysosomal pathway, consequently leading to an elevation in plasma LDL-C levels. Inhibiting PCSK9 prolongs the lifespan of LDLR and maintains cholesterol homeostasis in the body. Thus, PCSK9 is an innovative pharmacological target for treating hypercholesterolemia and atherosclerosis. In this study, we discovered that E28362 was a novel small-molecule PCSK9 inhibitor by conducting a virtual screening of a library containing 40,000 compounds. E28362 (5, 10, 20 μM) dose-dependently increased the protein levels of LDLR in both total protein and the membrane fraction in both HepG2 and AML12 cells, and enhanced the uptake of DiI-LDL in AML12 cells. MTT assay showed that E28362 up to 80 μM had no obvious toxicity in HepG2, AML12, and HEK293a cells. The effects of E28362 on hyperlipidemia and atherosclerosis were evaluated in three different animal models. In high-fat diet-fed golden hamsters, administration of E28362 (6.7, 20, 60 mg·kg -1 ·d -1 , i.g.) for 4 weeks significantly reduced plasma total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C) and PCSK9 levels, and reduced liver TC and TG contents. In Western diet-fed ApoE -/- mice (20, 60 mg·kg -1 ·d -1 , i.g.) and human PCSK9 D374Y overexpression mice (60 mg·kg -1 ·d -1 , i.g.), administration of E28362 for 12 weeks significantly decreased plasma LDL-C levels and the area of atherosclerotic lesions in en face aortas and aortic roots. Moreover, E28362 significantly increased the protein expression level of LDLR in the liver. We revealed that E28362 selectively bound to PCSK9 in HepG2 and AML12 cells, blocked the interaction between LDLR and PCSK9, and induced the degradation of PCSK9 through the ubiquitin-proteasome pathway, which finally resulted in increased LDLR protein levels. In conclusion, E28362 can block the interaction between PCSK9 and LDLR, induce the degradation of PCSK9, increase LDLR protein levels, and alleviate hyperlipidemia and atherosclerosis in three distinct animal models, suggesting that E28362 is a promising lead compound for the treatment of hyperlipidemia and atherosclerosis., (© 2024. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

Background: Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have emerged as a novel class of drugs with cardioprotective effects through their lipid-lowering effects., Objective: This review aims to discuss existing and novel strategies of PCSK9 inhibition, providing an overview of established randomized controlled trials and ongoing outcome trials that assess the efficacy and long-term safety of PCSK9 inhibitors. It also explores the evolving role of PCSK9 beyond lipid metabolism and outlines the pleiotropic actions of PCSK9 inhibition in various disorders and future directions including novel strategies to target PCSK9., Conclusion: PCSK9 inhibition shows promise not only in lipid metabolism but also in other disease processes, including atherosclerotic plaque remodeling, acute coronary syndrome, stroke, inflammation, and immune response., (© 2024 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.)

Infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause coronavirus disease 2019 (COVID-19), a disease with very heterogeneous symptoms. Dyslipidaemia is prevalent in at least 20% of Europeans, and dyslipidaemia before SARS-CoV-2 infection increases the risk for severe COVID-19 and mortality by 139%. Many reports described reduced serum cholesterol levels in virus-infected patients, in particular in those with severe disease. The liver is the major organ for lipid homeostasis and hepatic dysfunction appears to occur in one in five patients infected with SARS-CoV-2. Thus, SARS-CoV-2 infection, COVID-19 disease severity and liver injury may be related to impaired cholesterol homeostasis. These observations prompted efforts to assess the therapeutic opportunities of cholesterol-lowering medications to reduce COVID-19 severity. The majority of studies implicate statins to have beneficial effects on disease severity and outcome in COVID-19. Proprotein convertase subtilisin/kexin type 9 (PCSK9) antibodies have also shown potential to protect against COVID-19. This review describes the relationship between systemic cholesterol levels, liver injury and COVID-19 disease severity. The potential effects of statins and PCSK9 in COVID-19 are summarised. Finally, the relationship between cholesterol and lung function, the first organ to be affected by SARS-CoV-2, is described.

Background: Pancreatic adenocarcinoma (PAAD) is the most frequent kind of pancreatic cancer (PC). Recent studies suggest that lipid metabolism facilitates tumorigenesis, disease progression, and resistance to therapy by promoting lipid synthesis, accumulation, and breakdown. Thus, exploring the lipid metabolism network could unveil novel therapeutic avenues for early detection, precision medicine, and prognostication in PAAD. This project intends to develop new lipid metabolism-related biomarkers for PAAD diagnosis and investigate the link between important genes and immune cell infiltration (ICI)., Methods: Tissue samples from 20 PAAD patients and 20 healthy controls were obtained. Analysis were focused on the datasets GSE71729 and GSE16515, which include samples of PAAD (n = 161) and those from healthy human tissue (n = 61), derived from the GEO database. Knockdown of PCSK9 on PC cells were conducted by si-RNA and sh-RNA. Migration and cell functional experiments were performed to assess the role of PCSK9 in cell multiplication. Furthermore, a xenograft mouse model was employed to confirm PCSK9's function in vivo., Results: The expression level of Proprotein convertase subtilisin/kexin type 9 (PCSK9) is significantly elevated in tissues affected by PAAD when compared to normal tissues. Survival analyses indicated that increased PCSK9 levels are inversely related to overall and disease-free survival (DFS). PCSK9's functional annotation associated it with the cell cycle and metabolism, especially energy metabolism. Examination of ICI data determined that PCSK9 expression demonstrated an unambiguous association with the M0 macrophages, T follicular helper cells (Tfh), gamma delta T cells and activated DC, and an inverse relationship with Monocytes, CD8 + T cells, memory B cells, resting CD4 + memory T cells, activated NK cells and resting DC abundance. PCSK9 expression knockdown has the ability to impede PC cells' migration and proliferation., Conclusion: Our study identified PCSK9 as a critical gene in PAAD. Expression levels of PCSK9 varied between PAAD and normal samples. ROC analysis verified PCSK9's strong capacity to differentiate PC from normal samples. Importantly, PCSK9 expression was considerably elevated in PC cell lines and tissues. Furthermore, PCSK9 stimulates the migration and proliferation of tumor cells in vivo and vitro., (© 2024. The Author(s).)

Background: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have represented an important change in the management of hypercholesterolemia, although, until now, they have barely been used. Without PCSK9i, many patients with atherosclerotic cardiovascular disease (CVD) or those at very high risk do not reach their therapeutic LDLc objectives., Objective: The analysis aimed to examine the clinical and biochemical characteristics of subjects receiving PCSK9i treatment in the Dyslipidemia Registry of the Spanish Atherosclerosis Society., Methods: All consecutive subjects aged ≥ 18 years from different Lipid Units included in the Dyslipidemia Registry of the SEA were analyzed. Inclusion criteria consisted of unrelated patients aged ≥ 18 at the time of inclusion with hypercholesterolemia (LDL-C ≥ 130 mg/dL or non-HDL-C ≥ 160 mg/dL after the exclusion of secondary causes) who were studied for at least two years after inclusion. Participants' baseline and final visit clinical and biochemical characteristics were analyzed based on whether they were on primary or secondary prevention and whether they were taking PCSK9i at the end of follow-up., Results: Eight hundred twenty-nine patients were analyzed, 7014 patients in primary prevention and 1281 in secondary prevention at baseline. 4127 subjects completed the required follow-up for the final analysis. The median follow-up duration was 7 years (IQR 3.0-10.0). Five hundred patients (12.1%) were taking PCSK9i at the end of the follow-up. The percentage of PCSK9i use reached 35.6% (n = 201) and 8.7% (n = 318) in subjects with and without CVD, respectively. Subjects on PCSK9i and oral lipid-lowering agents with and without CVD achieved LDLc reductions of 80.3% and 75.1%, respectively, concerning concentrations without lipid-lowering drugs. Factors associated with PCSK9i use included increasing age, LDLc without lipid-lowering drugs and the Dutch Lipid Clinic Network (DLCN) score. However, hypertension, diabetes, smoking, and LDLc after oral lipid-lowering drugs were not independent factors associated with PCSK9i prescription. In subjects with CVD, the use of PCSK9i was higher in men than in women (an odds ratio of 1.613, P = 0.048)., Conclusions: Approximately one-third of CVD patients received PCSK9i at the end of follow-up. The use of PCSK9i was more focused on baseline LDLc concentrations rather than on CVD risk. Women received less PCSK9i in secondary prevention compared to men., (© 2024. The Author(s).)

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., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors declare the following competing interests. Some of content in the manuscript also appear in the patent P2023-0130 KR registered in the Republic of Korea. The patent pertains to FIR irradiation emitted from ceramic and carbon, which is linked to the data presented in this manuscript, indicating PCSK9 reduction. Ewha Womans University and the Korea Carbon Industry Promotion Agency (KCARBON) are the beneficiaries or potential beneficiaries of the patent., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Cardiovascular calcification is an important public health issue with an unmeet therapeutic need. We had previously shown that lysyl oxidase (LOX) activity critically influences vascular wall smooth muscle cells (VSMCs) and valvular interstitial cells (VICs) calcification by affecting extracellular matrix remodeling. We have delved into the participation of LOX in atherosclerosis and vascular calcification, as well as in the mineralization of the aortic valve., Methods: Immunohistochemical and expression studies were carried out in human atherosclerotic lesions and experimental models, valves from patients with aortic stenosis, VICs, and in a genetically modified mouse model that overexpresses LOX in CMLV (TgLOX CMLV ). Hyperlipemia and atherosclerosis was induced in mice through the administration of adeno-associated viruses encoding a PCSK9 mutated form (AAV-PCSK9 D374Y ) combined with an atherogenic diet., Results: LOX expression is increased in the neointimal layer of atherosclerotic lesions from human coronary arteries and in VSMC-rich regions of atheromas developed both in the brachiocephalic artery of control (C57BL/6J) animals transduced with PCSK9 D374Y and in the aortic root of ApoE -/- mice. In TgLOX CMLV mice, PCSK9 D374Y transduction did not significantly alter the enhanced aortic expression of genes involved in matrix remodeling, inflammation, oxidative stress and osteoblastic differentiation. Likewise, LOX transgenesis did not alter the size or lipid content of atherosclerotic lesions in the aortic arch, brachiocephalic artery and aortic root, but exacerbated calcification. Among lysyl oxidase isoenzymes, LOX is the most expressed member of this family in highly calcified human valves, colocalizing with RUNX2 in VICs. The lower calcium deposition and decreased RUNX2 levels triggered by the overexpression of the nuclear receptor NOR-1 in VICs was associated with a reduction in LOX., Conclusions: Our results show that LOX expression is increased in atherosclerotic lesions, and that overexpression of this enzyme in VSMC does not affect the size of the atheroma or its lipid content, but it does affect its degree of calcification. Further, these data suggest that the decrease in calcification driven by NOR-1 in VICs would involve a reduction in LOX. These evidences support the interest of LOX as a therapeutic target in cardiovascular calcification., (Copyright © 2024 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.)

Aims/hypothesis: Glomerular lipid accumulation is a defining feature of diabetic kidney disease (DKD); however, the precise underlying mechanism requires further elucidation. Recent evidence suggests a role for proprotein convertase subtilisin/kexin type 9 (PCSK9) in intracellular lipid homeostasis. Although PCSK9 is present in kidneys, its role within kidney cells and relevance to renal diseases remain largely unexplored. Therefore, we investigated the role of intracellular PCSK9 in regulating lipid accumulation and homeostasis in the glomeruli and podocytes under diabetic conditions. Furthermore, we aimed to identify the pathophysiological mechanisms responsible for the podocyte injury that is associated with intracellular PCSK9-induced lipid accumulation in DKD., Methods: In this study, glomeruli were isolated from human kidney biopsy tissues, and glomerular gene-expression analysis was performed. Also, db/db and db/m mice were used to perform glomerular gene-expression profiling. We generated DKD models using a high-fat diet and low-dose intraperitoneal streptozocin injection in C57BL/6 and Pcsk9 knockout (KO) mice. We analysed cholesterol and triacylglycerol levels within the kidney cortex. Lipid droplets were evaluated using BODIPY staining. We induced upregulation and downregulation of PCSK9 expression in conditionally immortalised mouse podocytes using lentivirus and siRNA transfection techniques, respectively, under diabetic conditions., Results: A significant reduction in transcription level of PCSK9 was observed in glomeruli of individuals with DKD. PCSK9 expression was also reduced in podocytes of animals under diabetic conditions. We observed significantly higher lipid accumulation in kidney tissues of Pcsk9 KO DKD mice compared with wild-type (WT) DKD mice. Additionally, Pcsk9 KO mouse models of DKD exhibited a significant reduction in mitochondria number vs WT models, coupled with a significant increase in mitochondrial size. Moreover, albuminuria and podocyte foot process effacement were observed in WT and Pcsk9 KO DKD mice, with KO DKD mice displaying more pronounced manifestations. Immortalised mouse podocytes exposed to diabetic stimuli exhibited heightened intracellular lipid accumulation, mitochondrial injury and apoptosis, which were ameliorated by Pcsk9 overexpression and aggravated by Pcsk9 knockdown in mouse podocytes., Conclusions/interpretation: The downregulation of PCSK9 in podocytes is associated with lipid accumulation, which leads to mitochondrial dysfunction, cell apoptosis and renal injury. This study sheds new light on the potential involvement of PCSK9 in the pathophysiology of glomerular lipid accumulation and podocyte injury in DKD., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12b system represents the third family of CRISPR-Cas systems that are harnessed for genome editing. However, only a few nucleases have demonstrated activity in human cells, and their in vivo therapeutic potential remains uncertain. In this study, a green fluorescent protein (GFP)-activation assay is conducted to screen a panel of 15 Cas12b orthologs, and four of them exhibited editing activity in mammalian cells. Particularly noteworthy is the NiCas12b derived from Nitrospira sp., which recognizes a "TTN" protospacer adjacent motif (PAM) and facilitates efficient genome editing in various cell lines. Importantly, NiCas12b also exhibits a high degree of specificity, rendering it suitable for therapeutic applications. As proof of concept, the adeno-associated virus (AAV) is employed to introduce NiCas12b to target the cholesterol regulatory gene proprotein convertase subtilisin/ kexin type 9 (Pcsk9) in the mouse liver. After 4 weeks of injections, an impressive is observed over 16.0% insertion/deletion (indel) efficiency, resulting in a significant reduction in serum cholesterol levels. NiCas12b provides a novel option for both basic research and clinical applications., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

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 PCSK9 lo group versus 57.9% relapsed in the PCSK9 hi group, P = 0.006) and survival status (39.6% dead in PCSK9 lo group versus 60.4% dead in PCSK9 hi 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., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Pyroptosis has been regarded as caspase-1-mediated monocyte death that induces inflammation, showing a critical and detrimental role in the development of cerebral ischemia-reperfusion injury (IRI). MARCH1 is an E3 ubiquitin ligase that exerts potential anti-inflammatory functions. Therefore, the study probed into the significance of MARCH1 in inflammation and pyroptosis elicited by cerebral IRI. Middle cerebral artery occlusion/reperfusion (MCAO/R)-treated mice and oxygen glucose deprivation/reoxygenation (OGD/R)-treated hippocampal neurons were established to simulate cerebral IRI in vivo and in vitro. MARCH1 and PCSK9 expression was tested in MCAO/R-operated mice, and their interaction was identified by means of the cycloheximide assay and co-immunoprecipitation. The functional roles of MARCH1 and PCSK9 in cerebral IRI were subsequently determined by examining the neurological function, brain tissue changes, neuronal viability, inflammation, and pyroptosis through ectopic expression and knockdown experiments. PCSK9 expression was increased in the brain tissues of MCAO/R mice, while PCSK9 knockdown reduced brain damage and neurological deficits. Additionally, inflammation and pyroptosis were inhibited in OGD/R-exposed hippocampal neurons upon PCSK9 knockdown, accompanied by LDLR upregulation and NLRP3 inflammasome inactivation. Mechanistic experiments revealed that MARCH1 mediated ubiquitination and degradation of PCSK9, lowering PCSK9 protein expression. Furthermore, it was demonstrated that MARCH1 suppressed inflammation and pyroptosis after cerebral IRI by downregulating PCSK9 both in vivo and in vitro. Taken together, the present study demonstrate the protective effect of MARCH1 against cerebral IRI through PCSK9 downregulation, which might contribute to the discovery of new therapies for improving cerebral IRI., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Proprotein convertase subtilisin/kexin type-9 (PCSK9) is a protein that regulates low-density lipoprotein (LDL) cholesterol metabolism by binding to the hepatic LDL receptor (LDLR), ultimately leading to its lysosomal degradation and an increase in LDL cholesterol (LDLc) levels. Treatment strategies have been developed based on blocking PCSK9 with specific antibodies (alirocumab, evolocumab) and on blocking its production with small regulatory RNA (siRNA) (inclisiran). Clinical trials evaluating these drugs have confirmed their high efficacy in reducing serum LDLc levels and improving the prognosis in patients with atherosclerotic cardiovascular diseases. Most studies have focused on the action of PCSK9 on LDLRs and the subsequent increase in LDLc concentrations. Increasing evidence suggests that the adverse cardiovascular effects of PCSK9, particularly its atherosclerotic effects on the vascular wall, may also result from mechanisms independent of its effects on lipid metabolism. PCSK9 induces the expression of pro-inflammatory cytokines contributing to inflammation within the vascular wall and promotes apoptosis, pyroptosis, and ferroptosis of cardiomyocytes and is thus involved in the development and progression of heart failure. The elimination of PCSK9 may, therefore, not only be a treatment for hypercholesterolaemia but also for atherosclerosis and other cardiovascular diseases. The mechanisms of action of PCSK9 in the cardiovascular system are not yet fully understood. This article reviews the current understanding of the mechanisms of PCSK9 action in the cardiovascular system and its contribution to cardiovascular diseases. Knowledge of these mechanisms may contribute to the wider use of PCSK9 inhibitors in the treatment of cardiovascular diseases., (© 2024. The Author(s).)

Hypercholesterolemia, characterized by elevated low-density lipoprotein (LDL) cholesterol levels, is a significant risk factor for cardiovascular disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a crucial role in cholesterol metabolism by regulating LDL receptor degradation, making it a therapeutic target for mitigating hypercholesterolemia-associated risks. In this context, we aimed to engineer human H ferritin as a scaffold to present 24 copies of a PCSK9-targeting domain. The rationale behind this protein nanoparticle design was to disrupt the PCSK9-LDL receptor interaction, thereby attenuating the PCSK9-mediated impairment of LDL cholesterol clearance. The N-terminal sequence of human H ferritin was engineered to incorporate a 13-amino acid linear peptide (Pep2-8), which was previously identified as the smallest PCSK9 inhibitor. Exploiting the quaternary structure of ferritin, engineered nanoparticles were designed to display 24 copies of the targeting peptide on their surface, enabling a multivalent binding effect. Extensive biochemical characterization confirmed precise control over nanoparticle size and morphology, alongside robust PCSK9-binding affinity (K D in the high picomolar range). Subsequent efficacy assessments employing the HepG2 liver cell line demonstrated the ability of engineered ferritin's ability to disrupt PCSK9-LDL receptor interaction, thereby promoting LDL receptor recycling on cell surfaces and consequently enhancing LDL uptake. Our findings highlight the potential of ferritin-based platforms as versatile tools for targeting PCSK9 in the management of hypercholesterolemia. This study not only contributes to the advancement of ferritin-based therapeutics but also offers valuable insights into novel strategies for treating cardiovascular diseases., (© 2024 The Author(s). Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

Purpose of Review: Inclisiran is a small interfering RNA that blocks hepatocyte production of the PCSK9 (proprotein convertase subtilisin/kexin type 9) protein by specifically targeting PCKS9 mRNA in the cytoplasm. This results in reduced degradation of LDL receptors and thus lowers LDL cholesterol by around 50% in addition to other lipid-lowering therapies. beyond 6 years of therapy. This review covers the latest published data and outlines future studies currently in process., Recent Findings: To date, half a million doses have been given worldwide with no untoward adverse events thus far. The twice-yearly injections make it potentially very user-friendly. The large phase 3a trials saw no diminution of effect with time up to nearly 7 years. Very large phase 3b randomized controlled trials are underway and may produce significant reductions in major adverse cardiovascular events., Summary: Inclisiran has been evaluated in numerous trials, primarily the ORION 9 26 , ORION 10 27 and ORION 11 28 studies, which demonstrated that in patients already on maximally tolerated statin therapy, biannual inclisiran injections reduced LDL cholesterol by up to 52% compared to placebo with a good safety profile. The only observed side effects were mild and transient at the injection site. As mentioned in the accompanying video, this adds to our armamentarium of lipid treatments., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

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., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Barbati et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

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., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is one of the major regulators of low-density lipoprotein receptor (LDLR). Information on role and regulation of PCSK9 in lung is very limited. Our study focuses on understanding the role and regulation of PCSK9 in the lung. PCSK9 levels are higher in Bronchoalveolar lavage fluid (BALF) of smokers with or without chronic obstructive pulmonary diseases (COPD) compared to BALF of nonsmokers. PCSK9-stimulated cells induce proinflammatory cytokines and activation of MAPKp38. PCSK9 transcripts are highly expressed in healthy individuals compared to COPD, pulmonary fibrosis or pulmonary systemic sclerosis. Cigarette smoke extract reduce PCSK9 levels in undifferentiated pulmonary bronchial epithelial cells (PBEC) but induce in differentiated PBEC. PCSK9 inhibition affect biological pathways, induces lipid peroxidation, and higher level of apoptosis in response to staurosporine. Our results suggest that higher levels of PCSK9 in BALF acts as an inflammatory marker. Furthermore, extracellular and intracellular PCSK9 play different roles., (© 2024. The Author(s).)

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a protein that regulates cholesterol levels by lysosomal low-density lipoprotein receptor (LDLR) degradation and has recently been associated with the production of neuronal oxidative stress and age-associated cardiovascular dysfunction. Since increased oxidative stress and vascular dysfunction are implicated in the pathology of aging and various neurodegenerative disorders, targeting PCSK9 may offer a promising therapeutic avenue for addressing these conditions. While the precise mechanisms through which PCSK9 contributes to vascular and neuronal oxidative stress in the brain remain elusive, preclinical studies have highlighted a neuroprotective effect linked to PCSK9 inhibition. This inhibition has shown promise in reducing oxidative stress, mitigating neuroinflammation, and alleviating neuropathological changes, thus underscoring the therapeutic potential of this approach in addressing neurodegenerative conditions.

Purpose of Review: Autosomal dominant hypercholesterolemia is a common cause of cardiovascular disease. In addition to the classic genes that cause hypercholesterolemia, LDLR, APOB and PCSK9 , a new locus has emerged as a candidate to be the cause of this hyperlipidemia, the p.(Leu167del) mutation in the APOE gene., Recent Findings: Various studies have demonstrated the involvement of the p.(Leu167del) mutation in the APOE gene in hypercholesterolemia: Studies of family segregation, lipoprotein composition by ultracentrifugation and proteomic techniques, and functional studies of VLDL-carrying p.(Leu167del) internalization with cell cultures have demonstrated the role of this mutation in the cause of hypercholesterolemia. The phenotype of individuals carrying the p.(Leu167del) in APOE is indistinguishable from familial hypercholesterolemia individuals with mutations in the classic genes. However, a better response to lipid-lowering treatment has been demonstrated in these APOE mutation carrier individuals., Summary: Therefore, APOE gene should be considered a candidate locus along with LDLR, APOB , and PCSK9 to be investigated in the genetic diagnosis of familial hypercholesterolemia., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: In vitro investigations have established metformin's capacity to downregulate proprotein convertase subtilisin/kexin type 9 (PCSK9) expression, suggesting a potential beneficial effect on atherogenic lipoprotein particles when combined with metformin therapy. Our objective was to assess whether metformin could mitigate statin-induced adverse effects on PCSK9, thereby improving lipid profiles in patients with coronary artery disease (CAD) but without diabetes. Employing an open-label, placebo-controlled, randomized trial, we randomized patients with CAD but without diabetes into CLA (cholesterol-lowering agents alone: atorvastatin ± ezetimibe, n = 38) and Met + CLA groups (metformin plus CLA, n = 33) in a 1:1 ratio. The primary end point was the therapeutic impact of 1-month metformin combination treatment on low-density lipoprotein cholesterol (LDL-C) and PCSK9 levels. Baseline LDL-C and PCSK9 levels were 76.18 mg·dL -1 and 80.54 ng·mL -1 , respectively. After 1 month, metformin significantly reduced LDL-C (-20.81%, P < 0.001), enabling 72% of patients to attain guideline-recommended LDL-C goals. Noteworthy reductions in PCSK9 levels (-15.03%, P < 0.001) were observed. Moreover, Met + CLA markedly reduced LDL particle number more than CLA alone (-10.65% vs. 1.45%, P = 0.009), primarily due to diminished small-dense LDL particle count. Mechanistically, our study demonstrated metformin's inhibition of statin-induced PCSK9 expression in human hepatocellular cells. In summary, a 1-month metformin combination regimen reduced LDL-C levels in patients with CAD but without diabetes by inhibiting PCSK9 expression., Trial Registration: Chinese Clinical Trial Registry identifier: ChiCTR1900026925 (26/10/2019)., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Acute kidney injury (AKI) is a devastating consequence of sepsis, accompanied by high mortality rates. It was suggested that inflammatory pathways are closely linked to the pathogenesis of lipopolysaccharide (LPS)-induced AKI. Inflammatory signaling, including PCSK9, HMGB1/RAGE/TLR4/MYD88/NF-κB, NLRP3/caspase-1 and Fractalkine/CX3CR1 are considered major forerunners in this link. Alirocumab, PCSK9 inhibitor, with remarkable anti-inflammatory features. Accordingly, this study aimed to elucidate the antibacterial effect of alirocumab against E. coli in vitro. Additionally, evaluation of the potential nephroprotective effects of alirocumab against LPS-induced AKI in rats, highlighting the potential underlying mechanisms involved in these beneficial actions. Thirty-six adult male Wistar rats were assorted into three groups (n=12). Group I; was a normal control group, whereas sepsis-mediated AKI was induced in groups II and III through single-dose intraperitoneal injection of LPS on day 16. In group III, animals were given alirocumab. The results revealed that LPS-induced AKI was mitigated by alirocumab, evidenced by amelioration in renal function tests (creatinine, cystatin C, KIM-1, and NGAL); oxidative stress biomarkers (Nrf2, HO-1, TAC, and MDA); apoptotic markers and renal histopathological findings. Besides, alirocumab pronouncedly hindered LPS-mediated inflammatory response, confirmed by diminishing HMGB1, TNF-α, IL-1β, and caspase-1 contents; the gene expression of PCSK9, RAGE, NF-ᴋB and Fractalkine/CX3CR1, along with mRNA expression of TLR4, MYD88, and NLRP3. Regarding the antibacterial actions, results showed that alirocumab displayed potential anti-bacterial activity against pathogenic gram-negative E. coli. In conclusion, alirocumab elicited nephroprotective activities against LPS-induced AKI via modulation of Nrf2/HO-1, PCSK9, HMGB1/RAGE/TLR4/MYD88/NF-ᴋB/NLRP3/Caspase-1, Fractalkine/CX3R1 and apoptotic axes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Purpose of Review: Monoclonal antibodies (mAb) targeting proprotein convertase subtilisin/kexin type 9 (PCSK9) have been established in cardiovascular risk prevention. The purpose of this review is to summarize the effects of PCSK9 inhibitors across different patient populations., Recent Findings: Long-term data on the use of evolocumab and alirocumab shows persisting low- density lipoprotein cholesterol (LDL-C) lowering and good tolerability. PCSK9 inhibitors are effective and safe in both sexes, in pediatric patients as well as in the elderly. Initiation of PCSK9 mAb during acute myocardial infarction is safe and leads to beneficial morphological plaque changes. The PCSK9 inhibitors evolocumab, alirocumab and inclisiran lower LDL-C in patients with heterozygous familial hypercholesterolemia (FH), while the response of patients with homozygous FH is heterogeneous. New areas of application beyond lipid lowering are currently investigated., Summary: PCSK9 inhibitors are safe, well tolerated, and effective in primary and secondary prevention in a wide range of patient populations., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of Review: To examine the safety of proprotein convertase subtilisinekexin type 9 (PCSK9) inhibitors in patients with diabetes, specifically focusing on their impact on glucose metabolism., Recent Findings: Patients with diabetes often require intensified lipid-lowering therapy. PCSK9 inhibitors can reduce low-density lipoprotein cholesterol (LDL-C) concentrations by approximately 60%, and significantly reduce cardiovascular risk when added to statin therapy. Some studies have suggested an association between low LDL-C levels and an increased risk of new-onset diabetes, and genetics has almost consistently shown an increased glucose concentration and risk of diabetes. Most clinical trials have not demonstrated a deterioration in glycaemic control in patients with diabetes after the use of PCSK9 inhibitors, and they do not lead to other significant treatment-emergent adverse events., Summary: Although the majority of patients with diabetes are undergoing background statin therapy, which may mask potential adverse effects of PCSK9 inhibitors on glycaemic control, current data suggest that the benefits outweigh the risks for diabetic patients using PCSK9 inhibitors. Considering the different nature of genetic studies and of clinical trials, close monitoring of glucose parameters is necessary, especially in individuals with prediabetes., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

A variety of mechanisms and drugs have been shown to attenuate cardiovascular disease (CVD) onset and/or progression. Recent researchers have identified a potential role of proprotein convertase subtilisin/kexin type 9 (PCSK9) in modulating lipid metabolism and reducing plasma low density lipoprotein (LDL) levels. PCSK9 is the central protein in the metabolism of LDL cholesterol (LDL-C) owing to its major function in LDL receptor (LDLR) degradation. Due to the close correlation of cardiovascular disease with lipid levels, many in vivo and in vitro investigations are currently underway studying the physiological role of PCSK9. Furthermore, many studies are actively investigating the mechanisms of various compounds that influence lipid associated-disorders and their associated cardiovascular diseases. PCSK9 inhibitors have been shown to have significant impact in the prevention of emerging cardiovascular diseases. Natural products can effectively be used as PCSK9 inhibitors to control lipid levels through various mechanisms. In this review, we evaluate the role of phytochemicals and natural products in the regulation of PCSK9, and their ability to prevent cardiovascular diseases. Moreover, we describe their mechanisms of action, which have not to date been delineated., (© 2024 John Wiley & Sons Ltd.)

Hypercholesterolemia is an independent risk factor for cardiovascular disease and lowering circulating levels of low-density lipoprotein cholesterol (LDL-C) can prevent and reduce cardiovascular events. MicroRNA-181d (miR-181d) can reduce the levels of triglycerides and cholesterol esters in cells. However, it is not known whether miR-181d-5p can lower levels of circulating LDL-C. Here, we generated two animal models of hypercholesterolemia to analyze the potential relationship between miR-181d-5p and LDL-C. In hypercholesterolemia model mice, adeno-associated virus (AAV)-mediated liver-directed overexpression of miR-181d-5p decreased the serum levels of cholesterol and LDL-C and the levels of cholesterol and triglyceride in the liver compared with control mice. Target Scan 8.0 indicated Proprotein convertase subtilisin/kexin type 9 (PCSK9) to be a possible target gene of miR-181d-5p, which was confirmed by in vitro experiments. miR-181d-5p could directly interact with both the PCSK9 3'-UTR and promoter to inhibit PCSK9 translation and transcription. Furthermore, Dil-LDL uptake assays in PCSK9 knockdown Huh7 cells demonstrated that miR-181d-5p promotion of LDL-C absorption was dependent on PCSK9. Collectively, our findings show that miR-181d-5p targets the PCSK9 3'-UTR to inhibit PCSK9 expression and to reduce serum LDL-C. miR-181d-5p is therefore a new therapeutic target for the development of anti-hypercholesterolemia drugs.

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

Mendelian randomization (MR) uses genetic variants as instrumental variables (IVs) to investigate causal relationships between traits. Unlike conventional MR, cis-MR focuses on a single genomic region using only cis-SNPs. For example, using cis-pQTLs for a protein as exposure for a disease opens a cost-effective path for drug target discovery. However, few methods effectively handle pleiotropy and linkage disequilibrium (LD) of cis-SNPs. Here, we propose cisMR-cML, a method based on constrained maximum likelihood, robust to IV assumption violations with strong theoretical support. We further clarify the severe but largely neglected consequences of the current practice of modeling marginal, instead of conditional genetic effects, and only using exposure-associated SNPs in cis-MR analysis. Numerical studies demonstrated our method's superiority over other existing methods. In a drug-target analysis for coronary artery disease (CAD), including a proteome-wide application, we identified three potential drug targets, PCSK9, COLEC11 and FGFR1 for CAD., (© 2024. The Author(s).)

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, I 2 , 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., (© 2024. The Author(s).)

The ODYSSEY OUTCOMES trial, comprising over 47 000 patient-years of placebo-controlled observation, demonstrated important reductions in the risk of recurrent ischaemic cardiovascular events with the monoclonal antibody to proprotein convertase subtilisin/kexin type 9 alirocumab, as well as lower all-cause death. These benefits were observed in the context of substantial and persistent lowering of low-density lipoprotein cholesterol with alirocumab compared with that achieved with placebo. The safety profile of alirocumab was indistinguishable from matching placebo except for a ∼1.7% absolute increase in local injection site reactions. Further, the safety of alirocumab compared with placebo was evident in vulnerable groups identified before randomization, such as the elderly and those with diabetes mellitus, previous ischaemic stroke, or chronic kidney disease. The frequency of adverse events and laboratory-based abnormalities was generally similar to that in placebo-treated patients. Thus, alirocumab appears to be a safe and effective lipid-modifying treatment over a duration of at least 5 years., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

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/β-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., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)