The Apolipoprotein E ε4 Allele-Dependent Relationship Between Serum Lipid Levels and Cognitive Function: A Population-Based Cross-sectional Study

Objectives: Till now, the effect of serum lipid levels on cognitive function is still controversial. The apolipoprotein E (APOE) ε4 allele is the most critical genetic risk factor for Alzheimer’s disease (AD) and cognitive impairment. Additionally, APOE ε4 allele has a major impact on lipid metabolism. The aim of this study was to investigate the APOE genotype-dependent relationship between peripheral serum lipid levels and cognitive impairment.

Methods: A total of 1,273 subjects aged 40–86 years participated in this cross-sectional study. Serum lipid levels and the APOE genotype were detected. Mini-Mental State Examination was used to diagnose the cognitive impairment or not. Univariate and multivariate analyses were used to analyze the relationships between APOE genotype, serum lipid levels, and cognition function.

Results: After controlling for all possible covariates, a significant interaction between low serum high-density lipoprotein and the APOE ε4 allele on cognitive impairment (Wald’s χ² = 4.269, df = 1, OR = 20.094, p = 0.039) was found in the total participants. In APOE ε4 carriers, low serum high-density lipoprotein was positively associated with cognitive impairment (Wald’s χ² = 8.200, df = 1, OR = 60.335, p = 0.004) and serum high-density lipoprotein levels were positively correlated with Mini-Mental State Examination score (r = 0.217, df = 176, p = 0.004). There was no significant correlation between serum total cholesterol (TC), low-density lipoprotein, triglycerides (TG) levels, and cognitive impairment in either the total participants or APOE ε4 carriers/non-carriers.

Conclusions: APOE ε4 carriers, but not non-carriers, with lower serum high-density lipoprotein had a higher prevalence of cognitive impairment and a lower Mini-Mental State Examination score. These results suggest that the APOE ε4 allele may affect the relationship between serum lipid levels and cognitive impairment. However, the specific mechanism needs to be further elucidated.

Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Is Not Induced in Artificial Human Inflammation and Is Not Correlated with Inflammatory Response

Lipoproteins, as well as proprotein convertase subtilisin/kexin type 9 (PCSK9), have been shown to play a key role in the innate immune response. However, knowledge about the role and kinetics of PCSK9 in human inflammation is currently insufficient. This study aimed to investigate the interaction between inflammation and lipid metabolism, including the possible role of PCSK9. A single-blinded, placebo-controlled cross-over study using the human endotoxin model was performed.

Lipoproteins, as well as proprotein convertase subtilisin/kexin type 9 (PCSK9), have been shown to play a key role in the innate immune response. However, knowledge about the role and kinetics of PCSK9 in human inflammation is currently insufficient. This study aimed to investigate the interaction between inflammation and lipid metabolism, including the possible role of PCSK9. A single-blinded, placebo-controlled cross-over study using the human endotoxin model was performed. Ten healthy men received lipopolysaccharide (LPS) or placebo on two different study days after overnight fasting. Lipoproteins as well as PCSK9 were measured repetitively over 48 h. PCSK9 plasma concentrations were not induced by LPS infusion, and no correlation between PCSK9 plasma concentrations and the degree of inflammation could be identified. The observed low-density lipoprotein (LDL) response to inflammation was more complex than anticipated, especially in the very early phase after the inflammatory stimulus. Baseline concentrations of LDL, as well as high-density lipoprotein (HDL), correlated negatively with inflammatory response. Our data suggest that the lipoprotein response to inflammation is independent of PCSK9. The proposed elevations of PCSK9 and suspected correlations between PCSK9 levels and inflammatory response are not supported by our data. (This study has been registered at ClinicalTrials.gov under registration no. NCT03392701.)

Moving Targets: Recent Advances in Lipid-Lowering Therapies

Statin therapy has delivered tremendous value to society by improving the burden of atherosclerotic cardiovascular disease. Nonetheless, atherosclerotic cardiovascular disease remains the leading cause of death globally. Technological advances such as in the field of genomics have revolutionized drug discovery and development and have revealed novel therapeutic targets to lower low-density lipoprotein cholesterol (LDL-C), as well as other detrimental lipids and lipoproteins. Therapeutic LDL-C lowering prevents atherosclerotic cardiovascular disease with an effect size proportional to absolute LDL-C reductions and time of exposure. This understanding supports the notion that reducing cumulative LDL-C exposure should be a key therapeutic target. PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibiting monoclonal antibodies provides the possibility of reducing LDL-C to very low levels. Novel therapeutic platforms such as RNA inhibition present opportunities to combine robust lipid lowering with infrequent dosing regimens, introducing therapies with vaccine-like properties. The position of lipid-lowering therapies with targets other than LDL-C, such as Lp(a) [lipoprotein(a)], TRL (triglyceride-rich lipoproteins), and remnant cholesterol, will likely be determined by the results of ongoing clinical trials. Current evidence suggests that reducing Lp(a) or TRLs could attenuate atherosclerotic cardiovascular disease risk in specific categories of patients. This review provides an overview of the latest therapeutic developments, focusing on their mechanisms, efficacy, and safety.

[CME-Laboratory 61: New European Consensus Recommendations on Dyslipidemia]

CME-Laboratory 61: New European Consensus Recommendations on Dyslipidemia Abstract. The lipid status primarily serves to estimate the risk of atherosclerotic cardiovascular diseases (ASCVD). LDL cholesterol (LDL-C) is the primary target of lipid-lowering therapies. NonHDL cholesterol and apolipoprotein B are secondary targets. The European Cardiology and Atherosclerosis Societies have lowered their treatment targets for all risk groups. Triglycerides and HDL cholesterol are also recommended for risk assessment, but are not therapeutic goals. Lipoprotein (a) is a strongly genetically determined ASCVD risk factor and contains a statin-resistant part of LDL-C. The quality of laboratory diagnostics for all lipid risk factors is in need of improvement due to the fact that it is too dependent on methods and in view of the indication of new and expensive lipid-modifying therapies.

Efficacy of Tiaoqiheying decoction in the treatment of spasmodic pain and lipid metabolism after acute ischemic stroke

Objective

To investigate the efficacy and safety of Tiaoqiheying decoction in treating acute ischemic stroke.

Methods

This prospective randomized study enrolled 102 patients with ischemic stroke who were randomly assigned to the control (placebo), external (external Tiaoqiheying decoction), and external/internal groups (oral and external Tiaoqiheying decoction) groups. Cholesterol (CHO), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels and the National Institute of Health Stroke Scale (NIHSS), modified Ashworth scale (AMS), visual analog scale (VAS), Barthel Index (BI), and Fugl–Meyer score (FMS) were determined before and after treatment.

Results

NIHSS scores were lower in the external/internal group than in the external and placebo groups. MAS and VAS scores for all patients were also lower after 4 weeks than before treatment, and they were significantly lower in the external/internal group versus the control group. CHO, TG, and LDL levels were significantly lower after 2 and 4 weeks, and their levels were lower in the external/internal group than in the other two groups. BI and FMS were higher in the external/internal group than in the other groups after 2 and 4 weeks of treatment.

Conclusion

Tiaoqiheying decoction may improve spasmodic pain and lipid metabolism after stroke.

[Translational Research Based on Understanding the Regulatory Mechanisms of in Vivo Behaviors of Fat-soluble Compounds]

Several fat-soluble compounds such as cholesterol and fat-soluble vitamins have important physiological activities in the body, and their excess and/or deficiency have been reported to be closely associated with the onset and progression of several conditions such as lifestyle-related diseases. It is important to clarify not only the physiological activities but also in vivo kinetics of fat-soluble compounds to understand their in vivo activity (toxicity). This review introduces our recent (reverse) translational research in a combination of basic and clinical studies to reveal the regulatory mechanisms of in vivo behaviors of fat-soluble compounds and effects of their disruption in humans.

Clinical characteristics and biomarkers of coronary microvascular dysfunction and obstructive coronary artery disease

Objective

The purpose of this study was to determine the clinical characteristics and biomarkers in patients with coronary microvascular dysfunction (CMVD) and to compare them with patients with obstructive coronary artery disease (OCAD).

Methods

We conducted a single-center, hospital-based, observational, descriptive, comparative, clinical study of 40 patients, including 20 patients with CMVD and 20 with OCAD. We assessed laboratory biomarkers (low-density lipoprotein [LDL], high-density lipoprotein [HDL], red blood cell distribution width [RDW], brain natriuretic protein [BNP], troponin I), and PET/CT coronary flow reserve was performed.

Results

The mean coronary flow reserve (CFR) in patients with CMVD was 1.96±0.55. Mean low-density lipoprotein cholesterol (LDL-C) levels were significantly higher in the CMVD subgroup (2.53±0.63 mmol/L) compared with the OCAD subgroup (1.76±0.97 mmol/L). Logistic regression analysis identified LDL-C as a predictor for the development of CMVD (odds ratio, 5.24).

Conclusion

It is difficult to differentiate between OCAD and CMVD based on the patient’s medical history, clinical characteristics, and coronary angiography results. Further investigations may be needed to allow an accurate diagnosis. CFR measurements based on non-invasive positron emission tomography/computed tomography may aid the diagnosis of CMVD. We also identified LDL-C as a predictor for the development of CMVD.

Apolipoprotein B100/Low-Density Lipoprotein Regulates Proteolysis and Functions of von Willebrand Factor under Arterial Shear

BACKGROUND

 Proteolytic cleavage of von Willebrand factor (VWF) by a plasma a disintegrin and metalloproteinase with a thrombospondin type 1 motifs, member 13 (ADAMTS13) is regulated by shear stress and binding of coagulation factor VIII, platelets or platelet glycoprotein 1b, and ristocetin to VWF.

OBJECTIVE

 Current study aims to identify novel VWF binding partners that may modulate VWF functions under physiological conditions.

METHODS

 A deoxyribonucleic acid aptamer-based affinity purification of VWF, followed by tandem mass spectrometry, functional, and binding assays was employed.

RESULTS

 Apolipoprotein B100/low-density lipoprotein (apoB100/LDL) was identified as a novel VWF-binding partner. Purified apoB100/LDL was able to accelerate the proteolytic cleavage of VWF by ADAMTS13 under shear in a concentration-dependent manner. This rate-enhancing activity was dramatically reduced when apoB100/LDL was oxidized. More interestingly, the oxidized apoB100/LDL appeared to compete with native apoB100/LDL for its enhancing activity on VWF proteolysis under shear. As a control, a purified apoA1/high-density lipoprotein (apoA1/HDL) or apoB48 exhibited a minimal or no activity enhancing VWF proteolysis by ADAMTS13 under the same conditions. Both VWF and ADAMTS13 were able to bind native or oxidized apoB100/LDL with high affinities. No binding interaction was detected between VWF (or ADAMTS13) and apoA1/HDL (or apoB48). Moreover, apoB100/LDL but not its oxidized products inhibited the adhesion of platelets to ultra large VWF released from endothelial cells under flow. Finally, significantly reduced ratios of high to low molecular weight of VWF multimers with increased levels of plasma VWF antigen were detected in LDLR-/- mice fed with high cholesterol diet.

CONCLUSION

 These results indicate that apoB100/LDL may be a novel physiological regulator for ADAMTS13-VWF functions.

Heterozygous Ldlr-Deficient Hamster as a Model to Evaluate the Efficacy of PCSK9 Antibody in Hyperlipidemia and Atherosclerosis

Proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis and atherogenesis. However, there are only limited rodent models, with a functional low-density lipoprotein receptor (LDLR) pathway and cholesteryl ester transfer protein (CETP) to evaluate the drug candidates targeting the PCSK9/LDLR pathway, that are translatable to humans. Here, by using our recently generated LDLR heterozygote (Ldlr+/−) hamster model with functional LDLR pathway and CETP function, we seek to evaluate the effect of a PCSK9 antibody, evolocumab, on dyslipidemia and atherosclerosis compared with ezetimibe, an effective inhibitor of cholesterol absorption, as a positive therapeutic control. We show that the plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were significantly increased in Ldlr+/− hamsters fed a high-fat high-cholesterol (HFHC) diet; therefore, areas of atherosclerotic lesion in the aorta were obviously increased and positively correlated with plasma LDL-C and TC. Circulating free PCSK9 was downregulated by the HFHC diet and was undetectable in the evolocumab treated group, as expected. Most importantly, either evolocumab or ezetimibe treatment prevented HFHC diet-induced hyperlipidemia and subsequent atherosclerotic plaque formation. The results indicate that Ldlr+/− hamsters fed an HFHC diet represent an ideal rodent model to evaluate drug candidates that affect LDLR pathways.

Relationship of Cardiorespiratory Fitness and Body Mass Index with the Incidence of Dyslipidemia among Japanese Women: A Cohort Study

Low cardiorespiratory fitness (CRF) and obesity are independent risk factors for dyslipidemia. We investigated the synergistic effects of CRF and obesity on the incidence of dyslipidemia among Japanese women. Of 7627 participants, 927 normolipidemic Japanese women completed a submaximal exercise test, medical examination, and a questionnaire on smoking and alcohol drinking. The incidence of dyslipidemia was defined as having at least one of the following: high-density lipoprotein cholesterol < 40 mg/dL, low-density lipoprotein cholesterol ≥ 140 mg/dL, fasting triglyceride ≥ 150 mg/dL, or physician-diagnosed dyslipidemia. Multivariable hazard ratios (HRs) and 95% confidence intervals (CI) were calculated using a Cox proportional hazard regression model. During the follow-up period of ≤16 years (median 1 year), 196 (21.1%) women developed dyslipidemia. Compared with those in the body mass index (BMI)-specific (< or ≥25.0 kg/m²) lowest CRF tertile, the multivariable HRs for dyslipidemia in the highest CRF tertile were 1.36 (95% CI, 0.75–2.48) for women with BMI ≥ 25 kg/m² and 0.70 (95% CI, 0.45–1.09) for those with BMI < 25 kg/m² (p < 0.01 for interaction). These results suggest that CRF and BMI are interdependent and, together, they affect the incidence of dyslipidemia among Japanese women. CRF is inversely related to a lower incidence of dyslipidemia with low BMI.

Demographic And Clinical Characteristics Of Patients Prescribed Proprotein Convertase Subtilisin/kexin Type 9 Inhibitor Therapy And Patients Whose Current Lipid-Lowering Therapy Was Modified

Purpose

Our objective was to describe the demographic and clinical characteristics of real-world patients in the US with elevated low-density lipoprotein cholesterol (LDL-C) whose lipid-lowering therapy (LLT) ─ both proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor and non-PCSK9 inhibitor ─ was actively modified.

Methods

This retrospective cohort study used linked laboratory (Prognos), pharmacy (IMS Formulary Impact Analyzer), and medical claims (IQVIA Dx/LRx or PharMetrics Plus) data. PCSK9 inhibitor–prescribed patients with LDL-C ≥70 mg/dL (multiply by 0.02586 for mmol/L) at the time of prescription were matched by LDL-C test date to patients whose non-PCSK9 inhibitor therapy was modified by intensifying statin therapy, switching statins without intensification, or augmenting with ezetimibe (N=12,345 in each cohort). Baseline demographics, use of LLT, LDL-C values, atherosclerotic cardiovascular disease (ASCVD) diagnoses and cardiovascular comorbidities, and occurrence of major adverse cardiovascular events (MACE) were assessed during the 2-year pre-index period.

Results

Mean age was 66.2 years in the PCSK9 inhibitor cohort and 64.1 years in the cohort whose LLT regimen was otherwise modified. Respectively, mean baseline LDL-C values were 150 and 121 mg/dL; 60.3% and 39.0% of patients had ASCVD diagnoses, and 9.6% and 5.1% had experienced a recent MACE. Prevalence of ASCVD diagnoses in the PCSK9 inhibitor and modified non-PCSK9 inhibitor cohorts, respectively, was 15.5% vs 9.1% for acute coronary syndrome, 20.7% vs 8.7% for coronary revascularization, and 22.2% vs 5.1% for possible familial hypercholesterolemia. In addition, 19.8% of patients in the PCSK9 inhibitor cohort were receiving both statins and ezetimibe vs 5.0% in the modified LLT cohort.

Conclusion

Physicians are prescribing PCSK9 inhibitor therapy to patients with markedly elevated LDL-C levels who also have comorbid risk factors for adverse cardiovascular events. These results may be of interest to payers and policymakers involved in devising access strategies for PCSK9 inhibitors.

Anti-Atherosclerotic Effects of Fruits of Vitex rotundifolia and Their Isolated Compounds via Inhibition of Human LDL and HDL Oxidation

Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) oxidation are well known to increase the risk for atherosclerosis. In our ongoing research on natural products with inhibitory activities against oxidation of lipoproteins, fruits of Vitex rotundifolia were found to be highly active. There is no report on the effects on LDL and HDL oxidation. Herein, we investigated the inhibitory effects of V. rotundifolia fruit extract and its six compounds, which are: (1) artemetin, (2) casticin, (3) hesperidin, (4) luteolin, (5) vitexin, and (6) vanillic acid, against LDL and HDL oxidation. The LDL and HDL oxidations were determined by measuring production of conjugated dienes and thiobarbituric acid reactive substances, amount of hyperchromicity and carbonyl content, change in electrical charge, and apoA-I aggregation. In addition, the contents of the compounds in the extracts were analyzed using HPLC-DAD. Consequently, extracts of Vitex rotundifolia fruits and compounds 2 and 4 suppressed oxidation of LDL and HDL, showing inhibition of lipid peroxidation, decrease of negative charges in lipoproteins, reduction of hyperchromicity, decrease in carbonyl contents, and prevention of apoA-I aggregation. In particular, compounds 2 and 4 exhibited more potent inhibitory effect on oxidation of LDL and HDL than the extracts, suggesting their protective role against atherosclerosis via inhibition of LDL and HDL oxidation. The contents of artemetin, casticin, and vanillic acid in the extracts were 1.838 ± 0.007, 8.629 ± 0.078, and 1.717 ± 0.006 mg/g, respectively.

Clinical Evaluation Of Evolocumab For The Treatment Of Homozygous Familial Hypercholesterolemia In Chinese Patients

Evolocumab, which can lower low-density lipoprotein (LDL) cholesterol levels by approximately 60% and prevent cardiovascular events in patients with cardiovascular disease, is a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9). Some studies have investigated its efficacy and safety in the treatment of the homozygous form of familial hypercholesterolemia (HoFH), and others have focused on its efficacy and safety in Asians with high cardiovascular risk. Although no direct evolocumab clinical trials have been conducted in Chinese HoFH patients, its efficacy and safety in the Chinese population should be similar to those in other ethnic groups.

The relationship between CYP7A1 polymorphisms, coronary artery disease & serum lipid markers

Polymorphic variants of the CYP7A1 gene can increase the risk of atherosclerosis-based coronary artery disease (CAD) and modify serum lipid markers. Method: We studied haplotype-tagging single nucleotide polymorphisms of CYP7A1 in the Caucasian population and if they are associated with CAD, its symptoms, and any of its risk factors. Results: We did not find the genetic variants of CYP7A1 to be associated with an increased risk of CAD. However, we did find that the common rs3808607 variant is associated with modified concentrations of serum total cholesterol and LDL. We also found that the C allele and the CC genotype of the rs11786580 are more frequent in patients with myocardial infarction. This association was especially strong after the group differentiation by sex.

The three members of the Vav family proteins form complexes that concur to foam cell formation and atherosclerosis

During foam cell formation and atherosclerosis development, the scavenger receptor CD36 plays critical roles in lipid uptake and triggering of atherogenicity via the activation of Vav molecules. The Vav family includes three highly conserved members known as Vav1, Vav2, and Vav3. As Vav1 and Vav3 were found to exert function in atherosclerosis development, it remains thus to decipher whether Vav2 also plays a role in the development of atherosclerosis. In this study we found that Vav2 deficiency in RAW264.7 macrophages significantly diminished oxidized LDL uptake and CD36 signaling, demonstrating that each Vav protein family member was required for foam cell formation. Genetic disruption of Vav2 in ApoE-deficient C57BL/6 mice significantly inhibited the severity of atherosclerosis. Strikingly, we further found that the genetic deletion of each member of the Vav protein family by CRISPR/Cas9 resulted in a similar alteration of transcriptomic profiles of macrophages. The three members of the Vav proteins were found to form complexes, and genetic ablation of each single Vav molecule was sufficient to prevent endocytosis of CD36. The functional interdependence of the three Vav family members in foam cell formation was due to their indispensable roles in transcriptomic programing, lipid uptake, and activation of the JNK kinase in macrophages.

Lipid Status During Combined Treatment in Prostate Cancer Patients

The aim of this study was to provide a specific review of current medical literature regarding the lipid profile during prostate carcinoma (PCa) treatment. The main aim was to analyze the results presented by different authors and to find a commonality in the changes occurring during the treatment-hormonotherapy. The levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol were measured before and after the follow-up treatment. The manuscripts reviewed came from the period between 2008 and 2016. The size of the studies ranged from 16 participants to 310. The mean age was from 65 to 74 years in all studies. The Q test was used to attain all lipid parameters and to specify heterogeneity (p < .0001). After 12 months of androgen deprivation therapy (ADT), the patients had a significantly higher level serum TC and TG.

Long-Term Association of Low-Density Lipoprotein Cholesterol With Cardiovascular Mortality in Individuals at Low 10-Year Risk of Atherosclerotic Cardiovascular Disease

BACKGROUND

The associations of low-density lipoprotein cholesterol (LDL-C) with cardiovascular disease (CVD) and coronary heart disease mortality in an exclusively low estimated 10-year risk group are not well delineated. We sought to determine the long-term associations of various LDL-C and non-high-density lipoprotein cholesterol (HDL-C) thresholds and CVD and coronary heart disease mortality in a large, low 10-year risk cohort.

METHODS

The study sample included participants of the CCLS (Cooper Center Longitudinal Study) without a history of CVD or diabetes mellitus and defined as low risk (<7.5%) for 10-year atherosclerotic CVD events at baseline based on Pooled Cohort Risk Assessment Equations. The associations of fasting LDL-C and non-HDL-C with CVD mortality were tested with Cox proportional hazards models.

RESULTS

In 36 375 participants (72% men, median age 42) followed for a median of 26.8 years, 1086 CVD and 598 coronary heart disease deaths occurred. Compared with LDL-C <100 mg/dL, LDL-C categories 100 to 129 mg/dL, 130 to 159 mg/dL, 160 to 189.9 mg/dL, and ≥190 mg/dL were associated with a significantly higher risk of CVD death, with hazard ratios of 1.4 (95% CI, 1.1-1.7), 1.3 (95% CI, 1.1-1.6), 1.9 (95% CI, 1.5-2.4), and 1.7 (95% CI, 1.3-2.3), and mean reductions in years free of CVD death of 1.8, 1.1, 4.3, and 3.9, respectively. After adjustment for atherosclerotic CVD risk factors, LDL-C categories 160 to 189 mg/dL and ≥190 mg/dL remained independently associated with CVD mortality, with hazard ratios of 1.7 (95% CI, 1.4-2.2) and 1.5 (95% CI, 1.2-2.1), respectively. In multivariable-adjusted models using non-HDL-C <130 mg/dL as the reference, non-HDL-C 160 to 189 mg/dL, 190 to 219 mg/dL, and ≥220 mg/dL were significantly associated with CVD death, with hazard ratios of 1.3 (95% CI, 1.1-1.6), 1.8 (95% CI, 1.4-2.2), and 1.5 (95% CI, 1.2-2.0), respectively. Restricting the cohort to those with 10-year risk <5% did not diminish the associations of LDL-C and non-HDL-C with CVD mortality.

CONCLUSIONS

In a low 10-year risk cohort with long-term follow-up, LDL-C and non-HDL-C ≥160 mg/dL were independently associated with a 50% to 80% increased relative risk of CVD mortality. These findings may have implications for future cholesterol treatment paradigms.

Acute Exposure of Collecting Lymphatic Vessels to Low-Density Lipoproteins Increases Both Contraction Frequency and Lymph Flow: An In Vivo Mechanical Insight

Background: Lymphatic vessels drain fluids and solutes from interstitial spaces and serosal cavities. Among the solutes, low-density lipoproteins (LDL) are drained and can be detected in peripheral lymph, where they have been reported to exert a modulatory action on lymphatic vessels intrinsic contraction rate. In the present work, we investigated lymphatic vessel mechanical properties (contraction frequency and amplitude) that may be modulated by LDL application and the consequence on lymph flow. Methods and Results: Human-derived LDL were resuspended in phosphate-buffered saline (PBS) and microinjected in the interstitial space surrounding spontaneously contracting lymphatic vessels of the rat diaphragm, in vivo. Vessels' contraction rate and diameter were measured in control conditions (PBS) and after LDL injection. Lymph flow (J_lymph) was computed from contraction rate and diameter change. In some animals, after the recording procedure, diaphragmatic tissue samples were excised and immunostained with antilymphatic muscle (LM) actin to investigate the correlation between LM signal level and contraction amplitude. Data indicate a positive, saturating correlation between the abundance of LM actin and contraction amplitude, and LDL microinjection caused an acute increase in contraction frequency (+126%), a reduction of contraction amplitude to 75% of that obtained after PBS injection, and a +63% increase in J_lymph. Conclusions: From our in vivo analysis of the mechanical parameters affected by LDL, J_lymph was increased by a predominant effect on the contraction rate rather than amplitude, suggesting that the still elusive messaging system might be linked to the pacemaker sites.

New Therapeutic Approaches for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic condition characterized by elevated plasma levels of low-density lipoprotein cholesterol (LDL-C), premature atherosclerotic cardiovascular disease, and considerable unmet medical need with conventional LDL-C-lowering therapies. Between 2012 and 2015, the US Food and Drug Administration approved four novel LDL-C-lowering agents for use in patients with FH based on the pronounced LDL-C-lowering efficacy of these medicines. We review the four novel approved agents, as well as promising LDL-C-lowering agents in clinical development, with a focus on their mechanism of action, efficacy in FH cohorts, and safety.

New evidence from plasma ceramides links apoE polymorphism to greater risk of coronary artery disease in Finnish adults

apoE, a key regulator of plasma lipids, mediates altered functionalities in lipoprotein metabolism and thus affects the risk of coronary artery disease (CAD). The significance of different apoE polymorphisms remains unclear; although the ε4 allele is clearly associated with increased cholesterol levels (which inform CAD risk), direct studies about apoE polymorphisms on CAD risk and development have yielded controversial results. Furthermore, certain species of ceramides-complex lipids abundant in plasma LDL-are markers of increased risk of myocardial infarction and cardiovascular death. Using a high-throughput MS approach, we quantified 30 molecular plasma ceramide species from a cohort of 2,160 apoE-genotyped (rs7412, rs429358) young adults enrolled in the population-based Cardiovascular Risk in Young Finns Study. We then searched this lipidome data set to identify new indications of pathways influenced by apoE polymorphisms and possibly related to CAD risk. This approach revealed a previously unreported association between apoE polymorphism and a consistently documented high-risk CAD marker, Cer(d18:1/16:0). Compared with the apoE ε3/3 reference group, plasma levels of apoE ε4 were elevated and those of apoE ε2 were lowered in all subjects without evidence of apoE-by-sex interactions. apoE associated with seven ceramides that are connected to atherogenically potent macrophages and/or lipoprotein particles; these associations could indicate a plausible linkage between apoE polymorphism and ceramide metabolism, leading to adverse plasma LDL metabolism and atherogenesis. In conclusion, new evidence from plasma ceramides links apoE polymorphism with an increased risk of CAD and extends our understanding of the role of apoE in health and disease.

Familial hypercholesterolemia with early coronary atherosclerotic heart disease: A case report

Patients with familial hypercholesterolemia usually present with high levels of serum low-density lipoprotein, xanthomas and early coronary artery disease. A 13 years old female patient was admitted to Children's Hospital of Chongqing Medical University presenting symptoms of heart failure. Laboratory tests showed that her cholesterol and low-density lipid levels were extremely high. Electrocardiogram test revealed that she had sinus tachycardia, QT lengthening and ST-T change. Multiple cardiac function abnormalities were diagnosed by echocardiogram. Multiple coronary artery stenosis was determined by computed tomography angiography. After the combination of lipid lowering, anti-thrombosis, and cardiac remodeling therapies, the patient's symptoms were significantly improved and the patient was discharged.

Functionality of C-Reactive Protein for Atheroprotection

C-reactive protein (CRP) is a pentameric molecule made up of identical monomers. CRP can be seen in three different forms: native pentameric CRP (native CRP), non-native pentameric CRP (non-native CRP), and monomeric CRP (mCRP). Both native and non-native CRP execute ligand-recognition functions for host defense. The fate of any pentameric CRP after binding to a ligand is dissociation into ligand-bound mCRP. If ligand-bound mCRP is proinflammatory, like free mCRP has been shown to be in vitro, then mCRP along with the bound ligand must be cleared from the site of inflammation. Once pentameric CRP is bound to atherogenic low-density lipoprotein (LDL), it reduces both formation of foam cells and proinflammatory effects of atherogenic LDL. A CRP mutant, that is non-native CRP, which readily binds to atherogenic LDL, has been found to be atheroprotective in a murine model of atherosclerosis. Thus, unlike statins, a drug that can lower only cholesterol levels but not CRP levels should be developed. Since non-native CRP has been shown to bind to all kinds of malformed proteins in general, it is possible that non-native CRP would be protective against all inflammatory states in which host proteins become pathogenic. If it is proven through experimentation employing transgenic mice that non-native CRP is beneficial for the host, then using a small-molecule compound to target CRP with the goal of changing the conformation of endogenous native CRP would be preferred over using recombinant non-native CRP as a biologic to treat diseases caused by pathogenic proteins such as oxidized LDL.

Attention-deficit/hyperactivity disorder is associated with reduced levels of serum low-density lipoprotein cholesterol in adolescents. Data from the population-based German KiGGS study

Objectives: Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial, complex and the most common neurodevelopmental disorder in childhood. In this analysis, we tested the hypothesis that altered serum lipid patterns are associated with ADHD. Methods: Using data from the nationwide, population-based German Health Interview and Examination Survey for Children and Adolescents (KiGGS), we compared serum levels of total cholesterol, high-density (HDL) and low-density lipoprotein (LDL) cholesterol, and also triglycerides, in participants with physician-diagnosed and/or suspected ADHD, as defined by a value of ≥7 on the hyperactivity-inattention subscale of the Strengths and Difficulties Questionnaire (SDQ), with non-ADHD controls. Results: Among 6,898 participants aged between 11 and 17 years, 666 (9.7%) had a physician-based diagnosis of ADHD and/or suspected ADHD. We found correlations between the parent-rated SDQ scores on the hyperactivity-inattention subscale and concentrations of triglycerides (r = 0.064, p < .001), total cholesterol (r = -0.026, p = .033), HDL cholesterol (r = -0.059, p < .001) and LDL cholesterol (r = -0.027, p = .031). In multivariate models, low serum levels of LDL cholesterol remained a significant predictor of ADHD (Exp(β) = 0.382, 95% confidence interval = 0.165-0.888, p = .025). Conclusions: Our findings in a large, nationwide and representative sample of German adolescents demonstrated a small, but significant and inverse link between LDL cholesterol levels and symptoms of ADHD. Further studies are required to decipher the biochemical mechanisms behind this relationship.

NOS1-derived nitric oxide facilitates macrophage uptake of low-density lipoprotein

Foam cell formation is a hallmark event during atherosclerosis. The current paradigm is that lipid uptake by a scavenger receptor in macrophages initiates necrosis core formation that characterizes atherosclerosis. We report that NOS1-derived nitric oxide (NO) facilitates low-density lipoprotein (LDL) uptake by macrophages independent of the inflammatory response. LDL uptake could be dramatically suppressed by NOS1 specific inhibitor 1-(2-trifluoromethylphenyl) imidazole (TRIM). Importantly, the notion that NOS1 can mediate uptake of lipoproteins suggests that the foam cell formation is regulated by NOS1-derived NO-mediated mechanism. This is a novel study involving NOS1 as a critical player of foam cell formation and reveals much about the key molecular proteins involved in atherosclerosis. Targeting NOS1 would be a useful strategy in reducing LDL uptake by macrophages and hence dampening the atherosclerosis progression.

Impact of Dysfunctional Protein Catabolism on Macrophage Cholesterol Handling

Protein catabolism in macrophages, which is accomplished mainly through autophagy- lysosomal degradation, ubiquitin-proteasome system, and calpains, is disturbed in atheroprone vessels. Moreover, growing evidence suggests that defects in protein catabolism interfere with cholesterol handling in macrophages. Indeed, decreases in autophagy facilitate the deposition of cholesterol in atheroprone macrophages and the subsequent development of vulnerable atherosclerotic plaques due to impaired catabolism of lipid droplets and limited efferocytic clearance of dead cells. The proteasome is responsible for the degradation of ATP-binding cassette transporters, which leads to impaired cholesterol efflux from macrophages. Overactivation of conventional calpains contributes to excessive processing of functional proteins, thereby accelerating receptor-mediated uptake of oxidized low-density lipoproteins (LDLs) and slowing cholesterol efflux. Furthermore, calpain-6, an unconventional nonproteolytic calpain in macrophages, potentiates pinocytotic uptake of native LDL and attenuates the efferocytic clearance of dead cells. Herein, we focus on recent progress in understanding how defective protein catabolism is associated with macrophage cholesterol handling and subsequent atherogenesis.