Antiatherogenic small, dense HDL--guardian angel of the arterial wall?

Meta-Analysis and Network Analysis Differentially Detect Various Pro-Inflammatory Mediators and Risk Factors for Type 2 Diabetes in the Elderly

Type 2 diabetes (T2D) has a pathophysiological component that includes inflammation. Inflammation-sensitive marker measurement may be helpful in determining the risk of complications for both older T2D patients and the public. This study aimed to investigate the association between blood pro-inflammatory mediators and the characteristics of elderly patients with T2D using meta and network analyses. The Web of Science, Scopus, PubMed, and Cochrane Library databases were selected as study methodology. The Quality in Prognosis Studies (QUIPS) tool in the meta-analysis assessed the studies' methodological quality. The selected studies were statistically analyzed using the META-MAR tool based on the standardized mean difference (SMD). The selected studies included nine examinations involving 6399 old people [+>+55 years old, 65.9+±+4.09 (mean+±+SD)]. The meta-analysis showed that pro-inflammatory mediators (SMD 0.82) and patient-related variables [risk factors (SMD 0.71)] were significantly associated with T2D (p+<+0.05). Subgroup analysis revealed that tumor necrosis factor alpha (TNF-α; SMD 1.08), body mass index (SMD 0.64), high-density lipoprotein (HDL; SMD -0.61), body weight (SMD 0.50), and blood pressure (SMD 1.11) were factors significantly associated with T2D (p+<+0.05). Network analysis revealed that among patient characteristics, diastolic blood pressure and, among inflammatory mediators, leptin were the most closely associated factors with T2D in older adults. Moreover, network analysis showed that TNF-α and systolic blood pressure were most closely associated with leptin. Overall, alternate techniques, such as meta-analysis and network analysis, might identify different markers for T2D in older people. A therapeutic decision-making process needs to consider these differences in advance.

Impaired HDL antioxidant and anti-inflammatory functions are linked to increased mortality in acute heart failure patients

AIMS

Acute heart failure (AHF) is typified by inflammatory and oxidative stress responses, which are associated with unfavorable patient outcomes. Given the anti-inflammatory and antioxidant properties of high-density lipoprotein (HDL), this study sought to examine the relationship between impaired HDL function and mortality in AHF patients. The complex interplay between various HDL-related biomarkers and clinical outcomes remains poorly understood.

METHODS

HDL subclass distribution was quantified by nuclear magnetic resonance spectroscopy. Lecithin-cholesterol acyltransferase (LCAT) activity, cholesterol ester transfer protein (CETP) activity, and paraoxonase (PON-1) activity were assessed using fluorometric assays. HDL-cholesterol efflux capacity (CEC) was assessed in a validated assay using [3H]-cholesterol-labeled J774 macrophages.

RESULTS

Among the study participants, 74 (23.5 %) out of 315 died within three months after hospitalization due to AHF. These patients exhibited lower activities of the anti-oxidant enzymes PON1 and LCAT, impaired CEC, and lower concentration of small HDL subclasses, which remained significant after accounting for potential confounding factors. Smaller HDL particles, particularly HDL3 and HDL4, exhibited a strong association with CEC, PON1 activity, and LCAT activity.

CONCLUSIONS

In patients with AHF, impaired HDL CEC, HDL antioxidant and anti-inflammatory function, and impaired HDL metabolism are associated with increased mortality. Assessment of HDL function and subclass distribution could provide valuable clinical information and help identify patients at high risk.

A Current Update on the Role of HDL-Based Nanomedicine in Targeting Macrophages in Cardiovascular Disease

High-density lipoproteins (HDL) are complex endogenous nanoparticles involved in important functions such as reverse cholesterol transport and immunomodulatory activities, ensuring metabolic homeostasis and vascular health. The ability of HDL to interact with a plethora of immune cells and structural cells places it in the center of numerous disease pathophysiologies. However, inflammatory dysregulation can lead to pathogenic remodeling and post-translational modification of HDL, rendering HDL dysfunctional or even pro-inflammatory. Monocytes and macrophages play a critical role in mediating vascular inflammation, such as in coronary artery disease (CAD). The fact that HDL nanoparticles have potent anti-inflammatory effects on mononuclear phagocytes has opened new avenues for the development of nanotherapeutics to restore vascular integrity. HDL infusion therapies are being developed to improve the physiological functions of HDL and to quantitatively restore or increase the native HDL pool. The components and design of HDL-based nanoparticles have evolved significantly since their initial introduction with highly anticipated results in an ongoing phase III clinical trial in subjects with acute coronary syndrome. The understanding of mechanisms involved in HDL-based synthetic nanotherapeutics is critical to their design, therapeutic potential and effectiveness. In this review, we provide a current update on HDL-ApoA-I mimetic nanotherapeutics, highlighting the scope of treating vascular diseases by targeting monocytes and macrophages.

The Link between Magnesium Supplements and Statin Medication in Dyslipidemic Patients

Many investigations have discovered a connection between statins and magnesium supplements. On one hand, increasing research suggests that chronic hypomagnesemia may be an important factor in the etiology of some metabolic illnesses, including obesity and overweight, insulin resistance and type 2 diabetes mellitus, hypertension, alterations in lipid metabolism, and low-grade inflammation. Chronic metabolic problems seem to be prevented by a high Mg intake combined with diet and/or supplements. On the other hand, it is known that statins lower the frequency of cardiac events, stroke, and mortality, not by lowering LDL-C, but by the capacity to reduce mevalonate formation. That will enhance endothelial function, inhibit vascular smooth muscle cell proliferation and migration and encourage macrophages to promote plaque stability and regression while reducing inflammation. Taking these factors into consideration, we did an extensive analysis of the relevant literature, comparing the effects of Mg² and statin medications on lipoproteins and, implicitly, on the key enzymes involved in cholesterol metabolism.

Preeclampsia Affects Lipid Metabolism and HDL Function in Mothers and Their Offspring

Preeclampsia (PE) is linked to an overall increased cardiovascular risk for both the mother and child. Functional impairment of high-density lipoproteins (HDL) may contribute to the excess cardiovascular risk associated with PE. In this study, we investigated the effects of PE on maternal and neonatal lipid metabolism, and the parameters of HDL composition and function. The study cohort included 32 normotensive pregnant women, 18 women diagnosed with early-onset PE, and 14 women with late-onset PE. In mothers, early- and late-onset PE was associated with atherogenic dyslipidemia, characterized by high plasma triglycerides and low HDL-cholesterol levels. We observed a shift from large HDL to smaller HDL subclasses in early-onset PE, which was associated with an increased plasma antioxidant capacity in mothers. PE was further associated with markedly increased levels of HDL-associated apolipoprotein (apo) C-II in mothers, and linked to the triglyceride content of HDL. In neonates of early-onset PE, total cholesterol levels were increased, whereas HDL cholesterol efflux capacity was markedly reduced in neonates from late-onset PE. In conclusion, early- and late-onset PE profoundly affect maternal lipid metabolism, potentially contributing to disease manifestation and increased cardiovascular risk later in life. PE is also associated with changes in neonatal HDL composition and function, demonstrating that complications of pregnancy affect neonatal lipoprotein metabolism.

Expanding the Molecular Disturbances of Lipoproteins in Cardiometabolic Diseases: Lessons from Lipidomics

The increasing global burden of cardiometabolic diseases highlights the urgent clinical need for better personalized prediction and intervention strategies. Early diagnosis and prevention could greatly reduce the enormous socio-economic burden posed by these states. Plasma lipids including total cholesterol, triglycerides, HDL-C, and LDL-C have been at the center stage of the prediction and prevention strategies for cardiovascular disease; however, the bulk of cardiovascular disease events cannot be explained sufficiently by these lipid parameters. The shift from traditional serum lipid measurements that are poorly descriptive of the total serum lipidomic profile to comprehensive lipid profiling is an urgent need, since a wealth of metabolic information is currently underutilized in the clinical setting. The tremendous advances in the field of lipidomics in the last two decades has facilitated the research efforts to unravel the lipid dysregulation in cardiometabolic diseases, enabling the understanding of the underlying pathophysiological mechanisms and identification of predictive biomarkers beyond traditional lipids. This review presents an overview of the application of lipidomics in the study of serum lipoproteins in cardiometabolic diseases. Integrating the emerging multiomics with lipidomics holds great potential in moving toward this goal.

Electronegative LDL Is Associated with Plaque Vulnerability in Patients with Ischemic Stroke and Carotid Atherosclerosis

Owing to the high risk of recurrence, identifying indicators of carotid plaque vulnerability in atherothrombotic ischemic stroke is essential. In this study, we aimed to identify modified LDLs and antioxidant enzymes associated with plaque vulnerability in plasma from patients with a recent ischemic stroke and carotid atherosclerosis. Patients underwent an ultrasound, a CT-angiography, and an ¹⁸F-FDG PET. A blood sample was obtained from patients (n = 64, 57.8% with stenosis ≥50%) and healthy controls (n = 24). Compared to the controls, patients showed lower levels of total cholesterol, LDL cholesterol, HDL cholesterol, apolipoprotein B (apoB), apoA-I, apoA-II, and apoE, and higher levels of apoJ. Patients showed lower platelet-activating factor acetylhydrolase (PAF-AH) and paraoxonase-1 (PON-1) enzymatic activities in HDL, and higher plasma levels of oxidized LDL (oxLDL) and electronegative LDL (LDL(-)). The only difference between patients with stenosis ≥50% and <50% was the proportion of LDL(-). In a multivariable logistic regression analysis, the levels of LDL(-), but not of oxLDL, were independently associated with the degree of carotid stenosis (OR: 5.40, CI: 1.15-25.44, p < 0.033), the presence of hypoechoic plaque (OR: 7.52, CI: 1.26-44.83, p < 0.027), and of diffuse neovessels (OR: 10.77, CI: 1.21-95.93, p < 0.033), indicating that an increased proportion of LDL(-) is associated with vulnerable atherosclerotic plaque.

Efficacy of Submicron Dispersible Free Phytosterols on Non-Alcoholic Fatty Liver Disease: A Pilot Study

BACKGROUND

No pharmacological treatment is yet approved for non-alcoholic fatty liver disease (NAFLD). Plant sterols have shown healthy properties beyond lowering LDL-cholesterol, including lowering triglycerides and lipoprotein plasma levels. Despite pre-clinical data suggesting their involvement in liver fat control, no clinical study has yet been successful.

AIMS

Testing a sub-micron, free, phytosterol dispersion efficacy on NAFLD.

METHODS

A prospective, uncontrolled pilot study was carried out on 26 patients with ≥17.4% liver steatosis quantified by magnetic resonance imaging. Subjects consumed daily a sub-micron dispersion providing 2 g of phytosterols. Liver fat, plasma lipids, lipoproteins, liver enzymes, glycemia, insulinemia, phytosterols, liposoluble vitamins and C-reactive protein were assessed at baseline and after one year of treatment.

RESULTS

Liver steatosis relative change was -19%, and 27% of patients reduced liver fat by more than 30%. Statistically and clinically significant improvements in plasma triglycerides, HDL-C, VLDL and HDL particle number and C-reactive protein were obtained, despite the rise of aspartate aminotransferase, glycemia and insulinemia. Though phytosterol plasma levels were raised by >30%, no adverse effects were presented, and even vitamin D increased by 23%.

CONCLUSIONS

Our results are the first evidence in humans of the efficacy of submicron dispersible phytosterols for the treatment of liver steatosis, dyslipidemia and inflammatory status in NAFLD.

Consuming High-Fat and Low-Fat Ground Beef Depresses High-Density and Low-Density Lipoprotein Cholesterol Concentrations, and Reduces Small, Dense Low-Density Lipoprotein Particle Abundance

We hypothesized that consumption of high-fat (HF) ground beef (24% fat) would not affect plasma concentrations of high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein (LDL-C), whereas low-fat (LF) ground beef (5% fat) would decrease HDL-C and LDL-C concentrations. In a randomized 2-period crossover, controlled feeding trial, 25 men (mean age and body mass index, 40 years and 31.2) consumed 115-g HF or LF patties, 5/week for 5 weeks with a 4-week washout. The HF treatment increased % energy from fat (p = 0.006) and saturated fat (p = 0.004) and tended (p = 0.060) to depress % energy from carbohydrates. The HF and LF treatments decreased the plasma concentrations of HDL-C (p = 0.001) and LDL-C (p = 0.011). Both ground beef treatments decreased the abundance of HDL_3a and increased the abundance of HDL₃ (p ≤ 0.003); the LF treatment also decreased the abundance of HDL_2b and HDL_2a (p ≤ 0.012). The HF and LF treatments decreased the abundance of LDL₃ and LDL₄ (p ≤ 0.024) and the HF treatment also decreased LDL₅ (p = 0.041). Contrary to our hypothesis, the HF treatment decreased plasma HDL-C and LDL-C concentrations despite increased saturated fat intake, and both treatments decreased the abundance of smaller, denser LDL subfractions.

BMI modifies HDL-C effects on coronary artery bypass grafting outcomes

BACKGROUND

Despite the recognized implications of high-density lipoprotein cholesterol (HDL-C) in cardiovascular diseases, the role of body mass index (BMI) in HDL-C association with cardiovascular outcomes remains unclear. This study investigated the possible modifying implications of BMI on the correlation between HDL-C and coronary artery bypass grafting (CABG) outcomes.

METHODS

The present cohort included isolated CABG patients (median follow-up: 76.58 [75.79-77.38] months). The participants were classified into three groups: 18.5 ≤ BMI < 25 (normal), 25 ≤ BMI < 30 (overweight), and 30 ≤ BMI < 35 (obese) kg/m². Cox proportional hazard models (CPHs) and restricted cubic splines (RCSs) were applied to evaluate the relationship between HDL-C and all-cause mortality as well as major adverse cardio-cerebrovascular events (MACCEs) in different BMI categories.

RESULTS

This study enrolled a total of 15,639 patients. Considering the final Cox analysis among the normal and overweight groups, HDL-C ≥ 60 was a significant protective factor compared to 40 < HDL-C < 60 for all-cause mortality (adjusted hazard ratio (aHR): 0.47, P: 0.027; and aHR: 0.64, P: 0.007, respectively). However, the protective effect of HDL-C ≥ 60 was no longer observed among patients with 30 ≤ BMI < 35 (aHR: 1.16, P = 0.668). RCS trend analyses recapitulated these findings; among 30 ≤ BMI < 35, no uniform inverse linear association was observed; after approximately HDL-C≈55, its increase was no longer associated with reduced mortality risk. RCS analyses on MACCE revealed a plateau effect followed by a modest rise in overweight and obese patients from HDL-C = 40 onward (nonlinear association).

CONCLUSIONS

Very high HDL-C (≥ 60 mg/dL) was not related to better outcomes among obese CABG patients. Furthermore, HDL-C was related to the post-CABG outcomes in a nonlinear manner, and the magnitude of its effects also differed across BMI subgroups.

The Role of High-Density Lipoprotein Cholesterol in 2022

PURPOSE OF THE REVIEW

High-density lipoproteins (HDL) are responsible for the transport in plasma of a large fraction of circulating lipids, in part from tissue mobilization. The evaluation of HDL-associated cholesterol (HDL-C) has provided a standard method for assessing cardiovascular (CV) risk, as supported by many contributions on the mechanism of this arterial benefit. The present review article will attempt to investigate novel findings on the role and mechanism of HDL in CV risk determination.

RECENT FINDINGS

The most recent research has been aimed to the understanding of how a raised functional capacity of HDL, rather than elevated levels per se, may be responsible for the postulated CV protection. Markedly elevated HDL-C levels appear instead to be associated to a raised coronary risk, indicative of a U-shaped relationship. While HDL-C reduction is definitely related to a raised CV risk, HDL-C elevations may be linked to non-vascular diseases, such as age-related macular disease. The description of anti-inflammatory, anti-oxidative and anti-infectious properties has indicated potential newer areas for diagnostic and therapeutic approaches. In the last two decades inconclusive data have arisen from clinical trials attempting to increase HDL-C pharmacologically or by way of recombinant protein infusions (most frequently with the mutant A-I Milano); prevention of stent occlusion or heart failure treatment have shown instead significant promise. Targeted clinical studies are still ongoing.

Anorexia Nervosa Is Associated with a Shift to Pro-Atherogenic Low-Density Lipoprotein Subclasses

Anorexia nervosa (AN) is a severe eating disorder affecting primarily female adolescents and younger adults. The energy deprivation associated with AN has been shown to alter lipoprotein metabolism, which may affect cardiovascular risk. However, the mechanisms leading to alterations in the composition, structure, and function of lipoproteins in AN patients are not well-understood yet. Here, we investigated the lipid abnormalities associated with AN, particularly changes in the distribution, composition, metabolism, and function of lipoprotein subclasses. In this exploratory study, we analyzed serum samples of 18 women diagnosed with AN (BMI < 17.5 kg/m2) and 24 normal-weight women (BMI from 18.5−24.9 kg/m2). Using the Quantimetrix Lipoprint® system, we determined low-density lipoprotein (LDL) subclass distribution, including quantitative measurements of very low-density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and high-density lipoprotein (HDL) subclass distribution. We quantified the most abundant apolipoproteins of HDL and assessed lecithin-cholesterol acyltransferase (LCAT) and cholesteryl-ester transfer protein (CETP) activities. In addition, anti-oxidative capacity of apoB-depleted serum and functional metrics of HDL, including cholesterol efflux capacity and paraoxonase activity were assessed. The atherogenic lipoprotein subclasses VLDL and small LDL particles were increased in AN. Levels of VLDL correlated significantly with CETP activity (rs = 0.432, p = 0.005). AN was accompanied by changes in the content of HDL-associated apolipoproteins involved in triglyceride catabolism, such as apolipoprotein C-II (+24%) and apoA-II (−27%), whereas HDL-associated cholesterol, phospholipids, and triglycerides were not altered. Moreover, AN did not affect HDL subclass distribution, cholesterol efflux capacity, and paraoxonase activity. We observed a shift to more atherogenic lipoprotein subclasses in AN patients, whereas HDL functionality and subclass distribution were not altered. This finding underpins potential detrimental effects of AN on lipid metabolism and the cardiovascular system by increasing atherosclerotic risk factors.

Assessment of Ex Vivo Antioxidative Potential of Murine HDL in Atherosclerosis

This chapter provides details on a simple and reproducible method used to determine the capacity of murine HDL to prevent the oxidation of LDL . The principle of the method is based on the rearrangement of double bonds of polyunsaturated fatty acids that occurs during the oxidation of human LDL , which generates a sigmoidal curve. The shape and length of the curve is modified in the presence of HDL , and such modifications are easily quantifiable by measuring the absorbance of conjugated dienes at 234 nm. The general technique described herein may be applied to evaluate the effect of HDL obtained from different experimental murine models of atherosclerosis.

The Effects of Acute and Chronic Exercise on Paraoxonase-1 (PON1): A Systematic Review With Meta-Analysis

Purpose: To determine the acute and chronic effects of exercise on Paraoxonase-1 (PON1) concentration and activity. Methods: A literature search was performed using 16 electronic databases. Effect sizes (ES) were computed and two-tailed α values < .05 and non-overlapping 95% confidence intervals (95%CI) were considered statistically significant. Heterogeneity, inconsistency (I²), and small-study effects using the LFK index were examined. Results: Eighteen studies (n = 377 participants) met the criteria for inclusion. The acute effects of exercise on PON1 concentration were trivial and non-significant (ES = -.03, 95%CI = -.39 to .34, p > .05), heterogeneous (p = .05), moderately inconsistent (I² = 48%), with minor asymmetry (LFK index = 1.34). The chronic effects of exercise on PON1 concentration were also trivial and non-significant (ES = -.04, 95%CI = -.53 to.45, p > .05), homogenous (p = .65), displayed low inconsistency (I² = 0%), and minor asymmetry (LFK index = -1.14). The acute effects of exercise on PON1 activity were trivial and non-significant (ES = .11, 95%CI = -.02 to.24, p > .05), homogenous (p = .85), showed low inconsistency (I² = 0%), and no asymmetry (LFK index = .82). The chronic effects of exercise on PON1 activity were trivial and non-significant (ES = .31, 95%CI = -.03 to.65, p > .05), homogenous (p = .17), moderately inconsistent (I² = 36%), with no asymmetry (LFK index = .60). Conclusion: Acute and chronic exercise training, overall, exerted a trivial effect on PON1 concentration and activity.

Dietary Strategies to Improve Cardiovascular Health: Focus on Increasing High-Density Lipoprotein Functionality

Cardiovascular disease is one of the leading causes of morbidity and mortality worldwide, with increasing incidence. A cornerstone of cardiovascular disease prevention is lifestyle modification through dietary changes to influence various risk factors such as obesity, hypertension and diabetes. The effects of diet on cardiovascular health are complex. Some dietary components and metabolites directly affect the composition and structure of high-density lipoproteins (HDL) and increase anti-inflammatory and vasoprotective properties. HDLs are composed of distinct subpopulations of particles of varying size and composition that have several dynamic and context-dependent functions. The identification of potential dietary components that improve HDL functionality is currently an important research goal. One of the best-studied diets for cardiovascular health is the Mediterranean diet, consisting of fish, olive oil, fruits, vegetables, whole grains, legumes/nuts, and moderate consumption of alcohol, most commonly red wine. The Mediterranean diet, especially when supplemented with extra virgin olive oil rich in phenolic compounds, has been shown to markedly improve metrics of HDL functionality and reduce the burden, or even prevent the development of cardiovascular disease. Particularly, the phenolic compounds of extra virgin olive oil seem to exert the significant positive effects on HDL function. Moreover, supplementation of anthocyanins as well as antioxidants such as lycopene or the omega-3 fatty acid eicosapentaenoic acid improve parameters of HDL function. In this review, we aim to highlight recent discoveries on beneficial dietary patterns as well as nutritional components and their effects on cardiovascular health, focusing on HDL function.

Good Cholesterol Gone Bad? HDL and COVID-19

The transmissible respiratory disease COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide since its first reported outbreak in December of 2019 in Wuhan, China. Since then, multiple studies have shown an inverse correlation between the levels of high-density lipoprotein (HDL) particles and the severity of COVID-19, with low HDL levels being associated with an increased risk of severe outcomes. Some studies revealed that HDL binds to SARS-CoV-2 particles via the virus's spike protein and, under certain conditions, such as low HDL particle concentrations, it facilitates SARS-CoV-2 binding to angiotensin-converting enzyme 2 (ACE2) and infection of host cells. Other studies, however, reported that HDL suppressed SARS-CoV-2 infection. In both cases, the ability of HDL to enhance or suppress virus infection appears to be dependent on the expression of the HDL receptor, namely, the Scavenger Receptor Class B type 1 (SR-B1), in the target cells. SR-B1 and HDL represent crucial mediators of cholesterol metabolism. Herein, we review the complex role of HDL and SR-B1 in SARS-CoV-2-induced disease. We also review recent advances in our understanding of HDL structure, properties, and function during SARS-CoV-2 infection and the resulting COVID-19 disease.

Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((3H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = -0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.

Proatherogenic Sialidases and Desialylated Lipoproteins: 35 Years of Research and Current State from Bench to Bedside

This review summarizes the main achievements in basic and clinical research of atherosclerosis. Focusing on desialylation as the first and the most important reaction of proatherogenic pathological cascade, we speak of how desialylation increases the atherogenic properties of low density lipoproteins and decreases the anti-atherogenic properties of high density lipoproteins. The separate sections of this paper are devoted to immunogenicity of lipoproteins, the enzymes contributing to their desialylation and animal models of atherosclerosis. In addition, we evaluate the available experimental and diagnostic protocols that can be used to develop new therapeutic approaches for atherosclerosis.

The Effect of a Persian Herbal Medicine Compound on the Lipid Profiles of Patients with Dyslipidemia: A Randomized Double-Blind Placebo-Controlled Clinical Trial

INTRODUCTION

It has been well established in the world that lipid disorders promote the development of atherosclerosis and its clinical consequences. This study aimed to assess the impacts of a Persian medicinal (PM) compound on lipid profile.

MATERIALS AND METHODS

From June 21 to October 21, 2020, a randomized double-blind controlled clinical trial was conducted with 74 dyslipidemic patients, who were randomly divided into two equally populated groups: one prescribed with a Persian medicinal herbal compound (n = 37) and a placebo group (n = 37). A Persian herbal medicine including fenugreek, sumac, and purslane is introduced. Biochemical parameters including 12-hour fasting serum levels of total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), very-low-density lipoprotein (VLDL), and triglyceride (TG) were measured before the initiation and after the completion of study protocol.

RESULTS

Percent changes of biochemical parameters include the following: intervention group = cholesterol: 35.22, Tg: 45.91, LDL: 24.81, HDL: 2.05, VLDL: 8.94 and placebo group = cholesterol: 6.94, Tg: -7.3, LDL: 7.37, HDL: 2.88, VLDL: -0.14. The serum levels of total cholesterol (p=0.01) and LDL (p=0.01) significantly decreased and no increase was recorded in HDL (p=0.03) levels over time in the intervention group. Furthermore, between-group analysis showed a statistically significant difference between the intervention and placebo groups in this regard. VLDL (p=0.2) and TG (p=0.2) levels also decreased, however not significantly.

CONCLUSION

This study showed that a Persian medicinal herbal compound could be safe and beneficial to decrease the levels of serum cholesterol and LDL in dyslipidemic patients. However, larger long-term studies are recommended to clarify this effect.

Changing Perspectives on HDL: From Simple Quantity Measurements to Functional Quality Assessment

High-density lipoprotein (HDL) comprises a heterogeneous group of particles differing in size, density, and composition. HDL cholesterol (HDL-C) levels have long been suggested to indicate cardiovascular risk, inferred from multiple epidemiological studies. The failure of HDL-C targeted interventions and genetic studies has raised doubts on the atheroprotective role of HDL-C. The current consensus is that HDL-C is neither a biomarker nor a causative agent of cardiovascular disorders. With better understanding of the complex nature of HDL which comprises a large number of proteins and lipids with unique functions, recent focus has shifted from HDL quantity to HDL quality in terms of atheroprotective functions. The current research is focused on developing laboratory assays to assess HDL functions for cardiovascular risk prediction. Also, HDL mimetics designed based on the key determinants of HDL functions are being investigated to modify cardiovascular risk. Improving HDL functions by altering its composition is the key area of future research in HDL biology to reduce cardiovascular risk.

Fetal High-Density Lipoproteins: Current Knowledge on Particle Metabolism, Composition and Function in Health and Disease

Cholesterol and other lipids carried by lipoproteins play an indispensable role in fetal development. Recent evidence suggests that maternally derived high-density lipoprotein (HDL) differs from fetal HDL with respect to its proteome, size, and function. Compared to the HDL of adults, fetal HDL is the major carrier of cholesterol and has a unique composition that implies other physiological functions. Fetal HDL is enriched in apolipoprotein E, which binds with high affinity to the low-density lipoprotein receptor. Thus, it appears that a primary function of fetal HDL is the transport of cholesterol to tissues as is accomplished by low-density lipoproteins in adults. The fetal HDL-associated bioactive sphingolipid sphingosine-1-phosphate shows strong vasoprotective effects at the fetoplacental vasculature. Moreover, lipoprotein-associated phospholipase A2 carried by fetal-HDL exerts anti-oxidative and athero-protective functions on the fetoplacental endothelium. Notably, the mass and activity of HDL-associated paraoxonase 1 are about 5-fold lower in the fetus, accompanied by an attenuation of anti-oxidative activity of fetal HDL. Cholesteryl ester transfer protein activity is reduced in fetal circulation despite similar amounts of the enzyme in maternal and fetal serum. This review summarizes the current knowledge on fetal HDL as a potential vasoprotective lipoprotein during fetal development. We also provide an overview of whether and how the protective functionalities of HDL are impaired in pregnancy-related syndromes such as pre-eclampsia or gestational diabetes mellitus.

Low CETP activity and unique composition of large VLDL and small HDL in women giving birth to small-for-gestational age infants

Cholesteryl ester transfer protein (CETP) regulates high density lipoproteins (HDL)-cholesterol (C) and HDL-C is essential for fetal development. We hypothesized that women giving birth to large-for-gestational-age (LGA) and small-for-gestational age (SGA) infants differed in longitudinal changes in lipoproteins, CETP activity and HDL-C and that placentas from women with higher or lower circulating HDL-C displayed differential expression of mRNAs involved in cholesterol/nutrient transport, insulin signaling, inflammation/ extracellular matrix (ECM) remodeling. Circulating lipids and CETP activity was measured during pregnancy, NMR lipidomics in late pregnancy, and associations with LGA and SGA infants investigated. RNA sequencing was performed in 28 placentas according to higher and lower maternal HDL-C levels. Lipidomics revealed high triglycerides in large VLDL and lipids/cholesterol/cholesteryl esters in small HDL in women giving birth to SGA infants. Placentas from women with higher HDL-C had decreased levels of CETP expression which was associated with mRNAs involved in cholesterol/nutrient transport, insulin signaling and inflammation/ECM remodeling. Both placental and circulating CETP levels were associated with growth of the fetus. Low circulating CETP activity at 36–38 weeks was associated with giving birth to SGA infants. Our findings suggest a link between increased maternal HDL-C levels, low CETP levels both in circulation and placenta, and SGA infants.

Obesity-Related Changes in High-Density Lipoprotein Metabolism and Function

In obese individuals, atherogenic dyslipidemia is a very common and important factor in the increased risk of cardiovascular disease. Adiposity-associated dyslipidemia is characterized by low high-density lipoprotein cholesterol (HDL-C) levels and an increase in triglyceride-rich lipoproteins. Several factors and mechanisms are involved in lowering HDL-C levels in the obese state and HDL quantity and quality is closely related to adiponectin levels and the bioactive lipid sphingosine-1-phosphate. Recent studies have shown that obesity profoundly alters HDL metabolism, resulting in altered HDL subclass distribution, composition, and function. Importantly, weight loss through gastric bypass surgery and Mediterranean diet, especially when enriched with virgin olive oil, is associated with increased HDL-C levels and significantly improved metrics of HDL function. A thorough understanding of the underlying mechanisms is crucial for a better understanding of the impact of obesity on lipoprotein metabolism and for the development of appropriate therapeutic approaches. The objective of this review article was to summarize the newly identified changes in the metabolism, composition, and function of HDL in obesity and to discuss possible pathophysiological consequences.

Treatment with PCSK9 inhibitors induces a more anti-atherogenic HDL lipid profile in patients at high cardiovascular risk

BACKGROUND

Proprotein Convertase Subtilisin/Kexin type 9 inhibitors (PCSK9-I) have been reported to cause a moderate increase in high-density lipoprotein (HDL) cholesterol in human studies. We thus evaluated the effect of two approved PCSK9-I on the concentration and lipid composition of HDL particle subclasses.

SUBJECTS AND METHODS

95 patients (62.8 ± 10.3 years old, 58% men), with or without statin and/or ezetimibe treatment and eligible for PCSK9-I therapy, received either evolocumab (140 mg) or alirocumab (75 or 150 mg). Their HDL particle profiles were measured by NMR spectroscopy at baseline and after 4 weeks of PCSK9-I treatment.

RESULTS

PCSK9-I treatment increased the level of HDL-C by 7%. The level of medium-sized HDL particles (M-HDL-P) increased (+8%) while the level of XL-HDL-P decreased (-19%). The lipid core composition was altered in the smaller S- and M-HDL-P, with a reduction in triglycerides (TG) and an enrichment in cholesterol esters (CE), whereas the for the larger XL- and L-HDL-P the relative CE content decreased and the TG content increased. Ezetimibe therapy differentially impacted the HDL particle distribution, independently of statin use, with an increase in S-HDL-P in patients not receiving ezetimibe.

CONCLUSIONS

As S- and M-HDL-P levels are inversely related to cardiovascular risk, PCSK9-I treatment may result in a more atheroprotective HDL particle profile, particularly in patients not concomitantly treated with ezetimibe.

Avocado Pear Pulp (Persea americana)-Supplemented Cake Improved Some Serum Lipid Profile and Plasma Protein in Rats

Avocado pear pulp (Persea americana) is indigenous to Mexico. It is widely cultivated and consumed all over the world. Its oil is rich in monounsaturated fatty acids (SFAs) and can be used to replace SFAs in a diet to lower low-density lipoprotein (LDL) and raise high-density lipoprotein (HDL). Consumers seek healthy foods that aid in reducing metabolic syndrome. The aim of this study is to evaluate the effects of the best acceptable cakes supplemented with 0%, 10%, 30%, and 50% avocado on the serum lipid profile and plasma protein in rats. Twenty-five rats separated into five groups of four test groups and one control group were fed individually for 14 days, after which blood samples were withdrawn and subjected to biochemical analysis. Intake of cake supplemented with avocado pear pulp resulted in significant (P < .05) increment in the body weight, total cholesterol, triglycerides and HDL, and serum protein and decrement in LDL of the rats. The group fed 50% supplemented cake showed highest increase in HDL and least decrease in LDL. Cake supplemented with 50% avocado pear pulp proved to be a better supplementation in reducing serum LDL and increasing serum HDL and serum protein in rats, indicating to be a promising nutraceutical for the management of cardiovascular diseases and its associated complications.

Current perspectives on the use of statins in the treatment of dyslipidaemic patients: focus on pitavastatin

A meeting entitled 'Current Perspective on the Use of Statins in the Treatment of Dyslipidemic Patients' was held in Stresa, Italy, on 27-28th June 2019. The presentations covered the 2019 European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) guidelines on dyslipidaemia, with discussion about the importance of controlling low-density lipoprotein cholesterol (LDL-C) and the pharmacological opportunities to reach the novel lipid goals. The roles of statins to manage dyslipidaemia in patients with different cardiovascular risks were also discussed. In particular, the efficacy and safety of pitavastatin for the treatment of dyslipidaemia were reviewed, highlighting its further advantages beyond LDL-C reduction. Therefore, the impact of statins on the glycaemic profile was discussed in view of the null/lower effect of pitavastatin as compared with other statins, as well as the interaction profile with other drugs commonly used. This meeting report summarizes the main messages of the discussion with a special focus on pitavastatin, whose main features in different settings are described.

High-Density Lipoprotein (HDL) Inhibits Serum Amyloid A (SAA)-Induced Vascular and Renal Dysfunctions in Apolipoprotein E-Deficient Mice

Serum amyloid A (SAA) promotes endothelial inflammation and dysfunction that is associated with cardiovascular disease and renal pathologies. SAA is an apoprotein for high-density lipoprotein (HDL) and its sequestration to HDL diminishes SAA bioactivity. Herein we investigated the effect of co-supplementing HDL on SAA-mediated changes to vascular and renal function in apolipoprotein E-deficient (ApoE^-/^-) mice in the absence of a high-fat diet. Male ApoE^-/- mice received recombinant human SAA or vehicle (control) by intraperitoneal (i.p.) injection every three days for two weeks with or without freshly isolated human HDL supplemented by intravenous (i.v.) injection in the two weeks preceding SAA stimulation. Aorta and kidney were harvested 4 or 18 weeks after commencement of treatment. At 4 weeks after commencement of treatment, SAA increased aortic vascular cell adhesion molecule (VCAM)-1 expression and F₂-isoprostane level and decreased cyclic guanosine monophosphate (cGMP), consistent with SAA stimulating endothelial dysfunction and promoting atherosclerosis. SAA also stimulated renal injury and inflammation that manifested as increased urinary protein, kidney injury molecule (KIM)-1, and renal tissue cytokine/chemokine levels as well as increased protein tyrosine chlorination and P38 MAPkinase activation and decreased in Bowman's space, confirming that SAA elicited a pro-inflammatory phenotype in the kidney. At 18 weeks, vascular lesions increased significantly in the cohort of ApoE^-/- mice treated with SAA alone. By contrast, pretreatment of mice with HDL decreased SAA pro-inflammatory activity, inhibited SAA enhancement of aortic lesion size and renal function, and prevented changes to glomerular Bowman's space. Taken together, these data indicate that supplemented HDL reduces SAA-mediated endothelial and renal dysfunction in an atherosclerosis-prone mouse model.

Association of the HDL-c Level with HsCRP, IL-6, U-NAG, RBP and Cys-C in Type 2 Diabetes Mellitus, Hypertension, and Chronic Kidney Disease: An Epidemiological Survey

PURPOSE

To explore the association between the anti-inflammatory and renal protective roles of high-density lipoprotein cholesterol (HDL-c) and its different levels in type 2 diabetes mellitus (T2D), hypertension (HTN), and chronic kidney disease (CKD) and to lay a theoretical basis for precise, maximum-benefit HDL-c-raising therapy for patients with these diseases.

PATIENTS AND METHODS

A total of 2127 participants (195 with T2D, 618 with HTN, 162 with CKD, and 1152 controls) were selected and divided into four groups according to their baseline HDL-c level, namely, low HDL-c (L-HDL-c, ≤1.03 mmol/L), medium HDL-c (M-HDL-c, 1.04-1.55 mmol/L), high HDL-c (H-HDL-c, 1.56-2.05 mmol/L) and extremely high HDL-c (E-HDL-c, ≥ 2.06 mmol/L). Serum and morning urine samples were collected to analyze the correlation between high-sensitivity C-reactive protein (HsCRP), interleukin-6 (IL-6), urine n-acetyl-β-d-glucosidase (U-NAG), retinol binding protein (RBP), and cystatin c (Cys-C) levels with the HDL-c levels.

RESULTS

The HDL-c levels of patients with T2D, HTN and CKD were universally lower than those in the control group in both sexes (p<0.05), while male patients also manifested a lower level of HDL-c than female patients. However, although they had lower values of the renal impairment index, female patients were found to have anomalously higher amounts of proinflammatory cytokines. In addition, the correlations between HsCRP and RBP levels and HDL-c levels were most significant in patients with HTN (p<0.05), whereas in patients with T2D and CKD, such relevance was less significant.

CONCLUSION

Existence of substantial differences in HDL-c levels between different types of disease and sex highlighted that a higher HDL level does not always predict a better clinical outcome of patients. Moreover, we found that both HsCRP and RBP correlated negatively with HDL-c in HTN patients, indicating that monitoring HsCRP and RBP may serve as indicators for therapeutic efficacy of HDL-c-raising medications in HTN patients.

Association of High-Density Lipoprotein Particles and High-Density Lipoprotein Apolipoprotein C-III Content With Cardiovascular Disease Risk According to Kidney Function: The Multi-Ethnic Study of Atherosclerosis

Background

Chronic kidney disease is associated with structural and compositional abnormalities in high‐density lipoprotein particles (HDLp). We examined associations of HDLp size, particle subfractions, and apolipoprotein C‐III content with incident cardiovascular disease (CVD) events across categories of estimated glomerular filtration rate (eGFR).

Methods and Results

Analyses included 6699 participants in MESA (Multi‐Ethnic Study of Atherosclerosis) with measurements of HDLp and 5723 participants with measurements of HDL apolipoprotein C‐III. Cox‐regression methods were used to evaluate associations between HDLp and apolipoproteins with CVD events. Larger HDLp size was associated with lower CVD risk in participants with lower eGFR: hazard ratio (95% CI) per SD higher mean HDL size was 1.00 (0.90–1.11) in eGFR ≥60 mL/min per 1.73 m², 0.65 (0.48–0.86) in eGFR 45 to 59 mL/min per 1.73 m², and 0.48 (0.25–0.93) in eGFR <45 mL/min per 1.73 m² (P for interaction=0.05). Associations of HDLp subfractions with CVD varied significantly by eGFR (P for interaction=0.04), with significant inverse associations between higher concentrations of large HDLp and CVD events across categories of kidney function, but nonsignificant results for small HDLp. Only HDLp without apolipoprotein C‐III was associated with lower risk of CVD events, with seemingly (albeit not statistically significant) stronger associations among participants with lower eGFR (P for interaction=0.19).

Conclusions

HDL particles of larger size and higher concentrations of large HDL and of HDL without apolipoprotein C‐III were associated with lower CVD risk, with risk estimates seemingly stronger among participants with lower eGFR. Future larger studies are needed to corroborate these findings.

Greater IL-6, D-dimer, and ICAM-1 Levels Are Associated With Lower Small HDL Particle Concentration in the Multicenter AIDS Cohort Study

OBJECTIVE

Low HDL cholesterol (HDL-C) is common in people living with HIV infection, which is associated with inflammation, and correlates with greater cardiovascular disease (CVD) risk. Particles of HDL are HDL subfractions, and in some general population studies, higher small HDL particle number (HDL-P) has been associated with lower CVD risk. The objective of this study was to determine whether HIV serostatus and systemic inflammation were associated with small HDL-P in the Multicenter AIDS Cohort Study (MACS).

METHOD

The MACS is composed of HIV-infected and HIV-uninfected men. Separate linear regression analyses were conducted to evaluate the associations between outcomes (small HDL-P, large HDL-P, total HDL-P, and HDL size) and variables of interest (interleukin-6 [IL-6], D-dimer, and intercellular adhesion molecule-1 [ICAM-1] levels), with adjustment for other CVD risk factors.

RESULTS

The study population included 553 HIV-infected (88.1% on current ART) and 319 HIV-uninfected men. The mean age was 52.7 years for HIV-infected men and 55.3 years for HIV-uninfected men. In separate models of the study population, higher log IL-6 was associated with lower total and small HDL-P (P < .01 for both), independent of HIV serostatus and CVD risk factors. Similar results were seen with ICAM-1. Positive HIV serostatus was associated with lower small and total HDL-P, adjusted for inflammatory markers.

CONCLUSIONS

Greater systemic inflammation and HIV infection both were associated with lower atheroprotective small HDL-P. This may be a potential mechanism contributing to increased cardiovascular risk among HIV-infected people.

AMPK-SIRT1-independent inhibition of ANGPTL3 gene expression is a potential lipid-lowering mechanism of metformin

Objectives

Hypertriglyceridaemia enhances cardiovascular disease risk in patients with diabetes. Lipoprotein lipase (LPL) regulates plasma triglyceride levels by hydrolysing chylomicrons and very-low-density lipoprotein (VLDL). Metformin, an antidiabetic drug, improves plasma lipids including triglycerides. We examined metformin's regulation of angiopoietin-like 3 (ANGPTL3), a liver-derived secretory protein with LPL inhibitory property.

Methods

Using HepG2 cells, a human hepatocyte cell line, the effects of metformin on ANGPTL3 gene and protein expression were determined. The role of AMPK-SIRT1 pathway in metformin regulation of ANGPTL3 was determined using pharmacological, RNAi and reporter assays. Metformin regulation of ANGPTL3 expression was also examined in sodium palmitate-induced insulin resistance.

Key findings

Metformin and pharmacological activators of AMPK and SIRT1 inhibited the expression of ANGPTL3 in HepG2 cells. Pharmacological or RNAi-based antagonism of AMPK or SIRT1 failed to affect metformin inhibition of ANGPTL3. AMPK-SIRT1 activators and metformin exhibited distinct effects on the expression of ANGPTL3 gene luciferase reporter. Sodium palmitate-induced insulin resistance in cells resulted in increased ANGPTL3 gene expression which was suppressed by pretreatment with metformin.

Conclusions

Metformin inhibits ANGPTL3 expression in the liver in an AMPK-SIRT1-independent manner as a potential mechanism to regulate LPL and lower plasma lipids.

Endothelial lipase increases antioxidative capacity of high-density lipoprotein

Endothelial lipase (EL) is a strong determinant of structural and functional properties of high-density lipoprotein (HDL). We examined whether the antioxidative capacity of HDL is affected by EL. EL-modified HDL (EL-HDL) and control EV-HDL were generated by incubation of HDL with EL- overexpressing or control HepG2 cells. As determined by native gradient gel electrophoresis, electron microscopy, and small-angle X-ray scattering EL-HDL is smaller than EV-HDL. Mass spectrometry revealed an enrichment of EL-HDL with lipolytic products and depletion of phospholipids and triacylglycerol. Kinetics of conjugated diene formation and HPLC-based malondialdehyde quantification revealed that EL-HDL exhibited a significantly higher resistance to copper ion-induced oxidation and a significantly higher capacity to protect low-density lipoprotein (LDL) from copper ion-induced oxidation when compared to EV-HDL. Depletion of the lipolytic products from EL-HDL abolished the capacity of EL-HDL to protect LDL from copper ion-induced oxidation, which could be partially restored by lysophosphatidylcholine enrichment. Proteomics of HDL incubated with oxidized LDL revealed significantly higher levels of methionine 136 sulfoxide in EL-HDL compared to EV-HDL. Chloramine T (oxidizes methionines and modifies free thiols), diminished the difference between EL-HDL and EV-HDL regarding the capacity to protect LDL from oxidation. In absence of LDL small EV-HDL and EL-HDL exhibited higher resistance to copper ion-induced oxidation when compared to respective large particles. In conclusion, the augmented antioxidative capacity of EL-HDL is primarily determined by the enrichment of HDL with EL-generated lipolytic products and to a lesser extent by the decreased HDL particle size and the increased activity of chloramine T-sensitive mechanisms.

Lipoproteins in Atherosclerosis Process

BACKGROUND

Dyslipidaemias is a recognized risk factor for atherosclerosis, however, new evidence brought to light by trials investigating therapies to enhance HDLcholesterol have suggested an increased atherosclerotic risk when HDL-C is high.

RESULTS

Several studies highlight the central role in atherosclerotic disease of dysfunctional lipoproteins; oxidised LDL-cholesterol is an important feature, according to "oxidation hypothesis", of atherosclerotic lesion, however, there is today a growing interest for dysfunctional HDL-cholesterol. The target of our paper is to review the functions of modified and dysfunctional lipoproteins in atherogenesis.

CONCLUSION

Taking into account the central role recognized to dysfunctional lipoproteins, measurements of functional features of lipoproteins, instead of conventional routine serum evaluation of lipoproteins, could offer a valid contribution in experimental studies as in clinical practice to stratify atherosclerotic risk.

Biological Consequences of Dysfunctional HDL

Epidemiological studies have suggested an inverse correlation between high-density lipoprotein (HDL) cholesterol levels and the risk of cardiovascular disease. HDLs promote reverse cholesterol transport (RCT) and possess several putative atheroprotective functions, associated to the anti-inflammatory, anti-thrombotic and anti-oxidant properties as well as to the ability to support endothelial physiology. The assumption that increasing HDL-C levels would be beneficial on cardiovascular disease (CVD), however, has been questioned as, in most clinical trials, HDL-C-raising therapies did not result in improved cardiovascular outcomes. These findings, together with the observations from Mendelian randomization studies showing that polymorphisms mainly or solely associated with increased HDL-C levels did not decrease the risk of myocardial infarction, shift the focus from HDL-C levels toward HDL functional properties. Indeed, HDL from atherosclerotic patients not only exhibit impaired atheroprotective functions but also acquire pro-atherogenic properties and are referred to as "dysfunctional" HDL; this occurs even in the presence of normal or elevated HDL-C levels. Pharmacological approaches aimed at restoring HDL functions may therefore impact more significantly on CVD outcome than drugs used so far to increase HDL-C levels. The aim of this review is to discuss the pathological conditions leading to the formation of dysfunctional HDL and their role in atherosclerosis and beyond.

The association between Hepcidin and arterial stiffness in a community-dwelling population

Background

An association of hepcidin with cardiovascular (CV) disease and atherosclerosis has been reported in different patient groups. However, it has not been well described clinically the association between hepcidin and arterial stiffness. In this study,We analysed the possible mechanism of Hepcidin and arterial stiffness.

Methods

This article related measurements of plasma hepcidin and arterial stiffness (carotid–femoral pulse wave velocity [PWV]) in a community-based sample.

Results

After a median follow-up interval of 4.8 years, multiple linear regression analysis revealed that hepcidin was independently associated with carotid–femoral PWV (β = 1.498, P < 0.001). In a multivariable linear regression analysis, HDL3-C levels were negatively and independently associated with hepcidin at baseline (β = − 0.857, P = 0.024). HDL2-C was not associated with hepcidin at baseline (β = − 1.121, P = 0.133).

Conclusions

We found an association between baseline hepcidin and follow-up arterial stiffness that was independent of age, gender and other vascular risk factors. We also identified an association between hepcidin and HDL3-C at baseline, which indicates that the HDL3-C level may reflect the change in cholesterol efflux from peripheral arteries and partly explain the relationship between hepcidin and the change of arterial stiffness.

Attenuation of atherogenic apo B-48-dependent hyperlipidemia and high density lipoprotein remodeling induced by vitamin C and E combination and their beneficial effect on lethal ischemic heart disease in mice

Background and aims

Atherosclerotic cardiovascular disease is highly prevalent and its underlying pathogenesis involves dyslipidemia including pro-atherogenic high density lipoprotein (HDL) remodeling. Vitamins C and E have been proposed as atheroprotective agents for cardiovascular disease management. However, their effects and benefits on high density lipoprotein function and remodeling are unknown. In this study, we evaluated the role of vitamin C and E on non HDL lipoproteins as well as HDL function and remodeling, along with their effects on inflammation/oxidation biomarkers and atherosclerosis in atherogenic diet-fed SR-B1 KO/ApoER61^h/h mice.

Methods and results

Mice were pre-treated for 5 weeks before and during atherogenic diet feeding with vitamin C and E added to water and diet, respectively. Compared to a control group, combined vitamin C and E administration reduced serum total cholesterol and triglyceride levels by decreasing apo B-48-containing lipoproteins, remodeled HDL particles by reducing phospholipid as well as increasing PON1 and apo D content, and diminished PLTP activity and levels. Vitamin supplementation improved HDL antioxidant function and lowered serum TNF-α levels. Vitamin C and E combination attenuated atherogenesis and increased lifespan in atherogenic diet-fed SR-B1 KO/ApoER61^h/h mice.

Conclusions

Vitamin C and E administration showed significant lipid metabolism regulating effects, including HDL remodeling and decreased levels of apoB-containing lipoproteins, in mice. In addition, this vitamin supplementation generated a cardioprotective effect in a murine model of severe and lethal atherosclerotic ischemic heart disease.

Metabolic disorders and inflammation are associated with familial combined hyperlipemia

BACKGROUND

Familial Combined Hyperlipidemia (FCH) is related to different metabolic disorders. The objective of this study was to evaluate the presence of alterations of hydrocarbonated metabolism and lipid profile together with inflammatory and adhesion molecules in subjects with FCH compared to controls.

METHODS

75 HFC patients and 75 healthy individuals were studied. Glucose, insulin, HOMA-IR index and lipid parameters, in addition to anti-oxidized LDL antibodies (Anti ox-LDL), small and dense LDL (sdLDL) and HDL subfractions, proinflammatory cytokines and adhesion molecules were measured.

RESULTS

FCH patients showed higher levels of hydrocarbonated metabolism parameters, total cholesterol, triglycerides, LDLc, Apolipoprotein B and non-HDLc (p < .001), and lower levels of HDLc (p < .001) and Apolipoprotein AI (p < .05) than controls. In addition, the inflammatory markers hsCRP, IL-6, IL-8, P-selectin, E-selectin and ICAM were all higher with (p < .05) respect to controls. The increase of sdLDL was correlated with the presence of IR and IL-6 levels. Significant differences in diameter and percentage of phenotype B LDL, small HDL subfractions and Anti ox-LDL were also detected between patients and controls.

CONCLUSIONS

The lipid characteristics of FCH are confirmed by IR and a low grade inflammatory state in patients, and are associated with the predominance of sdLDL and Anti ox-LDL.

Analyzing 2000 in Vivo Drug Delivery Data Points Reveals Cholesterol Structure Impacts Nanoparticle Delivery

Lipid nanoparticles (LNPs) are formulated using unmodified cholesterol. However, cholesterol is naturally esterified and oxidized in vivo, and these cholesterol variants are differentially trafficked in vivo via lipoproteins including LDL and VLDL. We hypothesized that incorporating the same cholesterol variants into LNPs-which can be structurally similar to LDL and VLDL-would alter nanoparticle targeting in vivo. To test this hypothesis, we quantified how >100 LNPs made with six cholesterol variants delivered DNA barcodes to 18 cell types in wild-type, LDLR-/-, and VLDLR-/- mice that were both age-matched and female. By analyzing ∼2000 in vivo drug delivery data points, we found that LNPs formulated with esterified cholesterol delivered nucleic acids more efficiently than LNPs formulated with regular or oxidized cholesterol when compared across all tested cell types in the mouse. We also identified an LNP containing cholesteryl oleate that efficiently delivered siRNA and sgRNA to liver endothelial cells in vivo. Delivery was as-or more-efficient as the same LNP made with unmodified cholesterol. Moreover, delivery to liver endothelial cells was 3 times more efficient than delivery to hepatocytes, distinguishing this oleate LNP from hepatocyte-targeting LNPs. RNA delivery can be improved by rationally selecting cholesterol variants, allowing optimization of nanoparticle targeting.

HDL-AuNPs-BMS Nanoparticle Conjugates as Molecularly Targeted Therapy for Leukemia

Gold nanoparticles (AuNPs) with adsorbed high-density lipoprotein (HDL) have been utilized to deliver oligonucleotides, yet HDL-AuNPs functionalized with small-molecule inhibitors have not been systematically explored. Here, we report an AuNP-based therapeutic system (HDL-AuNPs-BMS) for acute myeloid leukemia (AML) by delivering BMS309403 (BMS), a small molecule that selectively inhibits AML-promoting factor fatty acid-binding protein 4. To synthesize HDL-AuNPs-BMS, we use AuNP as a template to control conjugate size ensuring a spherical shape to engineer HDL-like nanoparticles containing BMS. The zeta potential and size of the HDL-AuNPs obtained from transmission electron microscopy demonstrate that the HDL-AuNPs-BMS are electrostatically stable and 25 nm in diameter. Functionally, compared to free drug, HDL-AuNPs-BMS conjugates are more readily internalized by AML cells and have more pronounced effects on downregulation of DNA methyltransferase 1 (DNMT1), induction of DNA hypomethylation, and restoration of epigenetically silenced tumor suppressor p15^INK4B coupled with AML growth arrest. Importantly, systemic administration of HDL-AuNPs-BMS conjugates into AML-bearing mice inhibits DNMT1-dependent DNA methylation, induces AML cell differentiation, and diminishes AML disease progression without obvious side effects. In summary, these data, for the first time, demonstrate HDL-AuNPs as an effective delivery platform with great potential to attach distinct inhibitors and HDL-AuNPs-BMS conjugates as a promising therapeutic platform to treat leukemia.

Human Apolipoprotein A1 at Solid/Liquid and Liquid/Gas Interfaces

An X-ray reflectivity study on the adsorption behavior of human apolipoprotein A1 (apoA1) at hydrophilic and hydrophobic interfaces is presented. It is shown that the protein interacts via electrostatic and hydrophobic interactions with the interfaces, resulting in the absorption of the protein. pH dependent measurements at the solid/liquid interface between silicon dioxide and aqueous protein solution show that in a small pH range between pH 4 and 6, adsorption is increased due to electrostatic attraction. Here, the native shape of the protein seems to be conserved. In contrast, the adsorption at the liquid/gas interface is mainly driven by hydrophobic effects, presumably by extending the hydrophobic regions of the amphipathic helices, and results in a conformational change of the protein during adsorption. However, the addition of differently charged membrane-forming lipids at the liquid/gas interface illustrates the ability of apoA1 to include lipids, resulting in a depletion of the lipids from the interface.

Pharmacological Intervention to Modulate HDL: What Do We Target?

The cholesterol concentrations of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) have traditionally served as risk factors for cardiovascular disease. As such, novel therapeutic interventions aiming to raise HDL cholesterol have been tested in the clinical setting. However, most trials led to a significant increase in HDL cholesterol with no improvement in cardiovascular events. The complexity of the HDL particle, which exerts multiple physiological functions and is comprised of a number of subclasses, has raised the question as to whether there should be more focus on HDL subclass and function rather than cholesterol quantity. We review current data regarding HDL subclasses and subclass-specific functionality and highlight how current lipid modifying drugs such as statins, cholesteryl ester transfer protein inhibitors, fibrates and niacin often increase cholesterol concentrations of specific HDL subclasses. In addition this review sets out arguments suggesting that the HDL3 subclass may provide better protective effects than HDL2.

Relations of GlycA and lipoprotein particle subspecies with cardiovascular events and mortality: A post hoc analysis of the AIM-HIGH trial

BACKGROUND

The Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes trial showed no incremental benefit of extended-release niacin (ERN) therapy added to simvastatin in subjects with cardiovascular disease (CVD).

OBJECTIVES

To examine the effects of ERN treatment on lipoprotein particles and GlycA, a new marker of systemic inflammation, and their relations with incident CVD events including mortality.

METHODS

GlycA and very low-density lipoprotein, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) particle subclasses were quantified by nuclear magnetic resonance spectroscopy using available stored baseline (n = 2754) and 1-year in-trial (n = 2581) samples. Associations with CVD events and all-cause mortality were assessed using multivariable Cox proportional hazards regression adjusted for age, sex, diabetes, treatment assignment, and lipoproteins.

RESULTS

Compared to placebo, ERN treatment lowered very low-density lipoprotein and LDL and increased HDL particle concentrations, increased LDL and HDL particle sizes (all P < .0001), but did not affect GlycA. Baseline and in-trial GlycA levels were associated with increased risk of CVD events: hazard ratio (HR) per SD increment, 1.17 (95% confidence interval [CI], 1.06-1.28) and 1.13 (1.02-1.26), respectively. However, none of the lipoprotein particle classes or subclasses was associated with incident CVD. By contrast, all-cause mortality was significantly associated with both GlycA (baseline HR: 1.46 [1.22-1.75]; in-trial HR: 1.41 [1.24-1.60]) and low levels of small HDL particles (baseline HR: 0.69 [0.56-0.86]; in-trial HR: 0.69 [0.56-0.86]).

CONCLUSIONS

This Atherothrombosis Intervention in Metabolic Syndrome with Low HDL/High Triglycerides and Impact on Global Health Outcomes trial post hoc substudy indicates that inflammation, as indexed by GlycA, is unaffected by ERN treatment but is significantly associated with the residual risk of CVD and death in patients treated to low levels of LDL cholesterol.

Review of biomarkers to assess the effects of switching from cigarettes to modified risk tobacco products

Context: One approach to reducing the harm caused by cigarette smoking, at both individual and population level, is to develop, assess and commercialize modified risk alternatives that adult smokers can switch to. Studies to demonstrate the exposure and risk reduction potential of such products generally involve the measuring of biomarkers, of both exposure and effect, sampled in various biological matrices.Objective: In this review, we detail the pros and cons for using several biomarkers as indicators of effects of changing from conventional cigarettes to modified risk products.Materials and methods: English language publications between 2008 and 2017 were retrieved from PubMed using the same search criteria for each of the 25 assessed biomarkers. Nine exclusion criteria were applied to exclude non-relevant publications.Results: A total of 8876 articles were retrieved (of which 7476 were excluded according to the exclusion criteria). The literature indicates that not all assessed biomarkers return to baseline levels following smoking cessation during the study periods but that nine had potential for use in medium to long-term studies.Discussion and conclusion: In clinical studies, it is important to choose biomarkers that show the biological effect of cessation within the duration of the study.

High-density lipoprotein 3 cholesterol is a predictive factor for arterial stiffness: a community-based 4.8-year prospective study

Background

Although drug trials with niacin and cholesteryl ester transfer protein inhibitors that substantially increase high-density lipoprotein-cholesterol (HDL-C) failed to reduce the risk of coronary heart disease, HDL protection of the cardiovascular system cannot be easily denied. Hence, it may be HDL subfractions that are responsible for the long-held and consistent cardioprotective association of HDL. Arterial stiffness has been increasingly recognized as a strong predictor of subclinical vascular disease, atherosclerotic disease, and cardiovascular mortality. As the association of HDL subfractions and arterial stiffness is not well characterized, we aimed to determine the relations between these two entities in a community-based longitudinal Chinese population sample.

Methods

We evaluated the associations of plasma HDL2-C and HDL3-C subfractions with arterial stiffness measured using carotid-femoral pulse wave velocity (cf-PWV) and then multivariate logistic regression in 1447 subjects (mean age 61.3 years) from a community-based population in Beijing, China.

Results

After a median follow-up of 4.8 years, Pearson’s correlation analysis revealed that HDL3-C was negatively associated with follow-up cf-PWV (r = −0.114; P = 0.001), and there was no correlation between HDL2-C and follow-up cf-PWV (r = −0.045; P = 0.181). In the multivariate logistic regression analysis, each standard deviation (SD) increase in HDL3-C was associated with a 1.490-increased likelihood of the presence of follow-up cf-PWV [odds ratio (per SD increase in HDL3-C) 1.490; 95% confidence interval 1.021–1.470; P = 0.039), whereas there was no relation between HDL2-C and follow-up cf-PWV.

Conclusions

HDL3-C subfractions were significantly and inversely associated with arterial stiffness, suggesting that HDL subfractions are likely more important than HDL-C in preventing cardiovascular disease.