Low-density lipoprotein particles in atherosclerosis

Among the diseases causing human death, cardiovascular disease (CVD) remains number one according to the World Health Organization report in 2021. It is known that atherosclerosis is the pathological basis of CVD. Low-density lipoprotein (LDL) plays a pivotal role in the initiation and progression of atherosclerotic CVD (ASCVD). LDL cholesterol (LDL-C) is the traditional biological marker of LDL. However, large numbers of patients who have achieved the recommended LDL-C goals still have ASCVD risk. In multiple prospective studies, LDL particle (LDL-P) is reported to be more accurate in predicting CVD risk than LDL-C. LDL-Ps differ in size, density and chemical composition. Numerous clinical studies have proved that the atherogenic mechanisms of LDL-Ps are determined not only by LDL number and size but also by LDL modifications. Of note, small dense LDL (sdLDL) particles possess stronger atherogenic ability compared with large and intermediate LDL subfractions. Besides, oxidized LDL (ox-LDL) is another risk factor in atherosclerosis. Among the traditional lipid-lowering drugs, statins induce dramatic reductions in LDL-C and LDL-P to a lesser extend. Recently, proprotein convertase subtilsin/kexin type 9 inhibitors (PCSK9i) have been demonstrated to be effective in lowering the levels of LDL-C, LDL-P, as well as CVD events. In this article, we will make a short review of LDL metabolism, discuss the discordance between LDL-C and LDL-P, outline the atherogenic mechanisms of action of LDL by focusing on sdLDL and ox-LDL, summarize the methods used for measurement of LDL subclasses, and conclude the advances in LDL-lowering therapies using statins and PCSK9i.

Current Options and Future Perspectives in the Treatment of Dyslipidemia

Low-density lipoprotein cholesterol (LDL-C) plays a crucial role in the development of atherosclerosis. Statin therapy is the standard treatment for lowering LDL-C in primary and secondary prevention. However, some patients do not reach optimal LDL-C target levels or do not tolerate statins, especially when taking high doses long-term. Combining statins with different therapeutic approaches and testing other new drugs is the future key to reducing the burden of cardiovascular disease (CVD). Recently, several new cholesterol-lowering drugs have been developed and approved; others are promising results, enriching the pharmacological armamentarium beyond statins. Triglycerides also play an important role in the development of CVD; new therapeutic approaches are also very promising for their treatment. Familial hypercholesterolemia (FH) can lead to CVD early in life. These patients respond poorly to conventional therapies. Recently, however, new and promising pharmacological strategies have become available. This narrative review provides an overview of the new drugs for the treatment of dyslipidemia, their current status, ongoing clinical or preclinical trials, and their prospects. We also discuss the new alternative therapies for the treatment of dyslipidemia and their relevance to practice.

Effect of the Early Application of Evolocumab on Blood Lipid Profile and Cardiovascular Prognosis in Patients with Extremely High-Risk Acute Coronary Syndrome

Proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors significantly reduce low-density lipoprotein cholesterol (LDL-C) and improve the prognosis of patients with acute coronary syndrome (ACS). However, the feasibility and safety of early application of PCSK9 inhibitors on the basis of statins combined with ezetimibe to strengthen lipid lowering in extremely high-risk coronary heart disease populations are still unknown.This study was a prospective, randomized controlled study. A total of 136 patients with extremely high-risk ACS with LDL-C ≥ 3.0 mmol/L after percutaneous coronary intervention (PCI) treatment were randomly assigned 1:1 to the control group (atorvastatin 40 mg/day and ezetimibe 10 mg/day) or the evolocumab group (evolocumab 140 mg every 2 weeks combined with atorvastatin 40 mg/day and ezetimibe 10 mg/day). We compared the blood lipid profiles, major adverse cardiovascular events (MACEs), and adverse reactions. MACEs included cardiogenic death, nonfatal myocardial infarction, nonfatal stroke, and readmission due to angina. Adverse reactions included allergies, myalgia, poor blood glucose control, and liver damage.Within 1 month, the average level of LDL-C in the evolocumab group decreased from 3.54 to 0.57 mmol/L and that in the control group decreased from 3.52 to 1.26 mmol/L. The LDL-C compliance (< 1.0 mmol/L) rate was significantly increased in the evolocumab group compared with the control group (82.35% versus 22.06%, P < 0.01). The average level of lipoprotein (a) (Lp (a) ) in the control group increased by 9.94 ± 51.93% from baseline after treatment, but evolocumab reduced the Lp (a) level (-38.84 ± 32.40%). Additionally, evolocumab further reduced the levels of apolipoprotein B/A1 (-70.56 ± 22.38% versus -51.29 ± 18.14%), cholesterol (-54.76 ± 18.10% versus -41.16 ± 18.14%), and apolipoprotein B (-66.47 ± 26.89% versus -46.78 ± 24.12%) compared with those in the control group, all P < 0.01. The blood lipid levels of both control and evolocumab groups stabilized after 1 month. During the 3-month follow-up, the incidence of MACEs after PCI was lower in the evolocumab group than in the control group (8.82% versus 24.59%, P = 0.015), and evolocumab combined with statins and ezetimibe did not increase the occurrence of adverse reactions (13.24% versus 11.48%, P = 0.762).In patients with extremely high-risk ACS with high levels of LDL-C, adding evolocumab to their treatment regimen as early as possible may enhance lipid lowering, increase the patient's LDL-C compliance rate in the short term, and improve cardiovascular prognosis but will not increase adverse reactions.

Association of Prior Statin Therapy With Cardiovascular Outcomes in Patients With Initial Diagnosis of OCAD and LDL-C Below 1.8 mmol/L

This study investigated the effect of prior statin therapy on cardiovascular outcomes in patients with a diagnosis of obstructive coronary artery disease (OCAD) and low-density lipoprotein cholesterol (LDL-C) <1.8 mmol/L. A total of 1330 patients with baseline LDL-C <1.8 mmol/L were included; 548 had received prior statin therapy [prior statin (+)] and 782 had no prior statin [prior statin (-)]. Major adverse cardiac and cerebral event (MACCE) during hospitalization and a median follow-up of 25 months were analyzed. Compared with the prior statin (-) group, who displayed similar atherosclerotic cardiovascular disease risk burden including 71.6% with hypertension, 39.1% with diabetes, and 76.1% with ≥3 risk factors, the prior statin (+) group had significantly lower incidence of composite MACCE, all-cause death and cardiovascular death. After multivariable adjustment, non-prior statin therapy was independently associated with all-cause death [hazard ratio (HR) 2.09, 95% confidence interval (CI), 1.13-3.87, P = .019] and cardiovascular death (HR 2.28, 95% CI, 1.04-5.00, P = .040), particularly in the subgroups aged ≥65 years and with hypertension. Overall, compared with "naturally" LDL-C <1.8 mmol/L without statin, prior statin therapy to achieve an LDL-C <1.8 mmol/L independently predicted a lower risk of all-cause and cardiovascular mortality in patients with a diagnosis of OCAD.

A Bibliometric Analysis of Familial Hypercholesterolemia From 2011 to 2021

Familial Hypercholesterolemia (FH), an autosomal dominant genetic disease, is increasingly emerging as a global threat. To learn more about the development of FH, 1 617 papers about FH and related research were retrieved in the Web of Science Core Collection from 2011 to 2021. Then, these publications were scientometrically analyzed based on CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, and references. The results showed that research on FH is at a stable stage. More FH research has been conducted in developed countries, implying the necessity for strengthening international cooperation and exchanges. We have obtained scholars, institutions, relevant journals, and representative literatures that play an important role in FH. The research direction of FH is on the mechanisms of FH and its complications, diagnosis, statin therapy, and new lipid-lowering drug therapy. Care is the research frontier in FH, and it is in an explosive period.

Gypenoside LVI improves hepatic LDL uptake by decreasing PCSK9 and upregulating LDLR expression

BACKGROUNDS

Atherosclerotic Cardiovascular Disease (ASCVD) is defined as ischemic or endothelial dysfunction-various inflammatory diseases, which is mainly caused by excessive low-density lipoprotein cholesterol (LDL-C) in circulating blood. Gynostemma pentaphyllum is a traditional Chinese medicine, and total Gypenosides are used for the treatment of hyperlipidemia and to reduce circulating proprotein convertase subtilisin/kexin type 9 (PCSK9) level. However, which gypenoside involved in the modulation of PCSK9 expression is still unknown.

PURPOSE

This study aimed to discover effective PCSK9 inhibitors from Gypenosides in accordance with the 2019 ESC/EAS guidelines.

METHODS

HPLC was employed to determine major six components of Gypenosides. The inhibitory activity on secreted PCSK9 in HepG2 of six major compounds from Gypenosides were screened by ELISA. The level of low-density lipoprotein (LDL) receptor (LDLR) was determined by Flow cytometry and Immunofluorescence. The expression levels of PCSK9, LDLR and Sterol-regulatory element binding proteins-2 (SREBP-2) were analyzed by qPCR and Western blot. DiI-LDL was added to evaluated LDL uptake into HepG2.

RESULTS

The results suggested that the mRNA and protein levels of PCSK9 were down-regulated by Gypenoside LVI and the LDLR degradation in lysosomes system was inhibited, thereby leading to an increasing in LDL uptake into HepG2 cells. Furthermore, Gypenoside LVI decreased PCSK9 expression induced by stains. Altogether, Gypenoside LVI enhances LDL uptake into HepG2 cells by increased LDLR level on cell-surface and suppressed PCSK9 expression.

CONCLUSION

This indicates that Gypenoside LVI can be used as a useful supplement for statins in the treatment of hypercholesterolemia. This is firstly reported that monomeric compound of G. pentaphyllum planted in Hunan province has the effect of increasing LDL-C uptake in hepatocytes via inhibiting PCSK9 expression.

Three Musketeers for Lowering Cholesterol: Statins, Ezetimibe and Evolocumab

Coronary heart disease (CHD) is closely related to hypercholesterolemia, and lowering serum cholesterol is currently the most important strategy in reducing CHD. In humans, the serum cholesterol level is determined mainly by three metabolic pathways, namely, dietary cholesterol intake, cholesterol synthesis, and cholesterol degradation in vivo. An intervention that targets the key molecules in the three pathways is an important strategy in lowering serum lipids. Statins inhibit 3-hydroxyl-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) to reduce low-density lipoprotein (LDL) by about 20% to 45%. However, up to 15% of patients cannot tolerate the potential side effects of high statin dosages, and several patients also still do not reach their optimal LDL goals after being treated with statins. Ezetimibe inhibits cholesterol absorption by targeting the Niemann-Pick C1-like 1 protein (NPC1L1), which is related to cholesterol absorption in the intestines. Ezetimibe lowers LDL by about 18% when used alone and by an additional 25% when combined with statin therapy. The proprotein convertase subtilisin/kexin type 9 (PCSK9) increases hepatic LDLR degradation, thereby reducing the liver's ability to remove LDL, which can lead to hypercholesterolemia. Evolocumab, which is a PCSK9 monoclonal antibody, can reduce LDL from baseline by 53% to 56%. The three drugs exert lipid-lowering effects by regulating the three key pathways in lipid metabolism. Combining any with the two other drugs on the basis of statin treatment has improved the lipid-lowering effect. Whether the combination of the three musketeers will reduce the side effects of monotherapy and achieve the lipid-lowering effect should be studied further in the future.

Vascular Macrophages in Atherosclerosis

Atherosclerosis is the main pathological basis for the occurrence of most cardiovascular diseases, the leading global health threat, and a great burden for society. It has been well established that atherosclerosis is not only a metabolic disorder but also a chronic, sterile, and maladaptive inflammatory process encompassing both innate and adaptive immunity. Macrophages, the major immune cell population in atherosclerotic lesions, have been shown to play critical roles in all stages of atherosclerosis, including the initiation and progression of advanced atherosclerosis. Macrophages have emerged as a novel potential target for antiatherosclerosis therapy. In addition, the macrophage phenotype is greatly influenced by microenvironmental stimuli in the plaques and presents complex heterogeneity. This article reviews the functions of macrophages in different stages of atherosclerosis, as well as the phenotypes and functions of macrophage subsets. New treatment strategies based on macrophage-related inflammation are also discussed.

Progress and perspectives in plant sterol and plant stanol research

Current evidence indicates that foods with added plant sterols or stanols can lower serum levels of low-density lipoprotein cholesterol. This review summarizes the recent findings and deliberations of 31 experts in the field who participated in a scientific meeting in Winnipeg, Canada, on the health effects of plant sterols and stanols. Participants discussed issues including, but not limited to, the health benefits of plant sterols and stanols beyond cholesterol lowering, the role of plant sterols and stanols as adjuncts to diet and drugs, and the challenges involved in measuring plant sterols and stanols in biological samples. Variations in interindividual responses to plant sterols and stanols, as well as the personalization of lipid-lowering therapies, were addressed. Finally, the clinical aspects and treatment of sitosterolemia were reviewed. Although plant sterols and stanols continue to offer an efficacious and convenient dietary approach to cholesterol management, long-term clinical trials investigating the endpoints of cardiovascular disease are still lacking.