Small dense low-density lipoprotein cholesterol compared to other lipoprotein biomarkers for predicting coronary heart disease among individuals with normal fasting glucose: The Multi-Ethnic Study of Atherosclerosis.

Objective: This study compared small dense low-density lipoprotein cholesterol (sdLDL-C) with apolipoprotein B (apo B), and low-density lipoprotein particles (LDL-P) in predicting CHD risk in generally healthy adults with normal fasting glucose (NFG). Methods: This study was conducted among participants with NFG in the Multi-Ethnic Study of Atherosclerosis (MESA) prospective cohort with measurements of sdLDL-C, LDL-P, and apo B available at baseline (2000-2002) and follow-up CHD data (through 2015) (N = 3,258). Biomarkers were evaluated as quartiles, and in categories using clinically and 75th percentile-defined cut-points. Discordance/concordance of sdLDL-C relative to other biomarkers was calculated using 75th percentile cut-points and linear regression residuals. Associations between individual biomarkers, sdLDL-C discordance and CHD incidence were evaluated using Cox proportional hazards regression. Results: There were 241 incident CHD events in this population through 2015. Higher sdLDL-C, apo B, LDL-P were similarly associated with increased CHD in individuals with NFG. Discordance of sdLDL-C with apo B or LDL-P by 75th percentiles was not significantly associated with CHD. Residuals discordantly higher/lower sdLDL-C relative to apo B (discordant high HR=1.26, 95% CI: 0.89, 1.78; discordant low HR=0.94, 95% CI: 0.68, 1.29) and LDL-P (discordant high HR=1.25, 95% CI: 0.88, 1.75; discordant low HR=0.84, 95% CI:0.60, 1.16), compared to those with concordant measures, had non-statistically significant higher/lower risk of CHD. Conclusions: Results suggest sdLDL-C, apo B and LDL-P are generally comparable for predicting CHD events in normoglycemic individuals. Larger studies are needed to confirm findings and to investigate whether measurement of sdLDL-C may be beneficial to evaluate as an additional risk-enhancing factor.

Unravelling mechanisms of protein and lipid oxidation in mayonnaise at multiple length scales.

In mayonnaise, lipid and protein oxidation are closely related and the interplay between them is critical for understanding the chemical shelf-life stability of mayonnaise. This is in particular the case for comprehending the role of low-density lipoprotein (LDL) particles acting as a main emulsifier. Here, we monitored oxidation and the concomitant aggregation of LDLs by bright-field light microscopy and cryogenic transmission electron microscopy. We further probed the formation of protein radicals and protein oxidation by imaging the accumulation of a water-soluble fluorescent spin trap and protein autofluorescence. The effect of variation of pH and addition of EDTA on the accumulation of the spin trap validated that protein radicals were induced by lipid radicals. Our data suggests two main pathways of oxidative protein radical formation in LDL particles: (1) at the droplet interface, induced by lipid free radicals formed in oil droplets, and (2) in the continuous phase induced by an independent LDL-specific mechanism.

Influencing factors of coronary artery stenosis in patients with stable coronary heart disease and a correlation analysis.

OBJECTIVE: To explore the relationship of the size and concentration of low density lipoprotein (LDL) particles and high density lipoprotein (HDL) particles and the coronary stenotic degree of stable coronary artery disease. METHODS: Altogether 62 patients with coronary disease confirmed by coronary angiography treated in our hospital from March 2019 to March 2020 were selected as the observation group, and 62 healthy persons in the same period were chosen as the control group. The particle size of LDL and HDL protein complexes were measured and we then calculated the concentration ratio to explore the relationship between the two types of lipoprotein particles and the degree of coronary artery disease. The Gensini integral method and the lesion numbers were used to evaluate the coronary stenotic degree. RESULTS: In comparison with the control group, the mean diameter of the average LDL particle in the observation group was smaller, but the type B ratio and Gensini score were higher (P<0.05). In comparison with the control group, the observation group had a higher Sd-LDL concentration ratio, as well as concentration of small-particle HDL, percentage of concentration of small-particle HDL in the whole HDL concentration and Gensini score (P<0.05). In comparison with the single-vessel disease group, the multi-vessel disease group had a smaller LDL concentration, as well as smaller large-particle HDL concentration and percentage of large-particle HDL concentration in the whole HDL concentration, and SD-LDL concentration ratio, small-particle HDL concentration, and percentage of small-particle HDL concentration in the whole HDL concentration and Gensini points were considerably higher (P<0.05). The Gensini score in the observation group showed negative correlations with LDL particle size (r=-0.375, P<0.05), and positive correlations with the concentration of large-particle HDL (r=0.301, P<0.05). CONCLUSION: The size and concentration of LDL and HDL are significantly related to the coronary stenotic degree in SCAD disease, suggesting that they play a role in the coronary stenotic degree.

Lipoprotein Particle Profiles Compared With Standard Lipids in the Association With Subclinical Aortic Valve Calcification in Apparently Healthy Japanese Men.

BACKGROUND: Risk factors for atherosclerotic disease including dyslipidemia have been shown to be associated with aortic valve calcification (AVC). Nuclear magnetic resonance (NMR)-measured lipoprotein particles, low-density and high-density lipoprotein particles (LDL-p, HDL-p) in particular, have emerged as novel markers of atherosclerotic disease; however, whether NMR-measured particles are associated with AVC remains to be determined. This study aimed to examine the association between NMR-based lipoprotein particle measurements and standard lipids with AVC. The primary variables of interest were LDL-p (nmol/L), HDL-p (µmol/L), LDL-cholesterol, and HDL-cholesterol (both in mg/dL).Methods and Results:A community-based random sample of Japanese men aged 40-79 years examined in 2006-2008, in Shiga, Japan was studied. Presence of AVC was defined as an Agatston score >0. Lipoprotein particles were measured using NMR spectroscopy. In the main analysis, multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for the prevalence of AVC across the higher quartiles of lipids in reference to the lowest ones were obtained. Of 874 participants analyzed, 153 men had AVC. Multivariable-adjusted ORs of prevalent AVC for the highest vs. the lowest quartile were significantly elevated for LDL-p (OR, 2.20; 95% CI: 1.23-3.93) and LDL-cholesterol (OR, 2.16; 95% CI: 1.23-3.78). In contrast, neither HDL-p nor HDL-cholesterol was associated with AVC. CONCLUSIONS: The association of prevalent AVC with NMR-based LDL-p was comparable to that with LDL-cholesterol.

Enhanced blood-brain barrier penetration and glioma therapy mediated by T7 peptide-modified low-density lipoprotein particles.

Therapeutic outcome for the treatment of glioma was often limited due to the non-targeted nature and low permeability of drugs across the blood-brain barrier (BBB). An ideal glioma-targeted delivery system need to traverse the BBB and then target glioma cells with adequate optimized physiochemical properties and biocompatibility. However, it is an enormous challenge to the researchers to engineer the above-mentioned features into a single nanocarrier particle. New frontiers in nanomedicine are advancing the research of new biomaterials. In this study, we demonstrate a strategy for glioma targeting by encapsulating vincristine sulfate (VCR) into a naturally available low-density lipoprotein particles (LDL)-based drug delivery system with the modification of T7 peptide ligand (T7-LDL). LDL, endogenous lipid transporters, can specifically bind to brain endothelial cells and glioma cells via interacting with the low-density lipoprotein receptors (LDLR). T7 is a seven-peptide ligand of transferrin receptors (TfR) capable of circumventing the BBB and then targeting glioma. By combining the dual-targeting delivery effect of T7 peptide and parent LDL, T7-LDL displayed higher glioma localization than that of parent LDL. After loading with VCR, T7-LDL showed the most favorable antiglioma effect in vitro and in vivo. These results demonstrated that T7-LDL is an important potential drug delivery system for glioma-targeted therapy.

Cholesterol delivery to the adrenal glands estimated by adrenal venous sampling: An in vivo model to determine the contribution of circulating lipoproteins to steroidogenesis in humans.

BACKGROUND: Cholesterol, required for adrenal steroid hormone synthesis, is at least in part derived from circulating lipoproteins. The contribution of high-density lipoproteins (HDL) and low-density lipoproteins (LDL) to adrenal steroidogenesis in humans is unclear. OBJECTIVE: The aim of the study was to determine the extent to which HDL and LDL are taken up by the adrenal glands using samples obtained during adrenal venous sampling (AVS). METHODS: AVS was successfully performed in 23 patients with primary aldosteronism. Samples were drawn from both adrenal veins and inferior vena cava (IVC). HDL cholesterol (HDL-C) and lipoprotein particle profiles were determined by nuclear magnetic resonance spectroscopy. Apolipoprotein (apo) A-I and apoB were assayed by immunoturbidimetry. RESULTS: Plasma HDL-C and HDL and LDL particle concentrations (HDL-P and LDL-P) were not lower in samples obtained from the adrenal veins compared with the IVC (HDL-C, P = .59; HDL-P, P = .06; LDL-P, P = .93). ApoB was lower in adrenal venous plasma than in IVC (P = .026; P < .05 for right adrenal vein). In 13 patients with an aldosterone producing adenoma (APA), apoB was also lower (P = .045) and LDL-P tended to be lower (P = .065) in the APA adrenal vein compared with the IVC. ApoA-I was not lower in adrenal venous plasma compared with the IVC, neither in the whole group (P = .20) nor in the APA subgroup (P = .075). CONCLUSION: These in vivo observations suggest that circulating LDL may contribute to adrenal steroidogenesis in humans as inferred from adrenal venous-IVC apoB concentration differences. AVS is a feasible method to investigate the relationships between lipoproteins and steroidogenesis.

The missing pieces of the HCV entry puzzle.

The past decade has witnessed steady and rapid progress in HCV research, which has led to the recent breakthrough in therapies against this significant human pathogen. Yet a deeper understanding of the life cycle of the virus is required to develop more affordable treatments and to advance vaccine design. HCV entry presents both a challenge for scientific research and an opportunity for alternative intervention approaches, owning to its highly complex nature and the myriad of players involved. More than half a dozen cellular proteins are implicated in HCV entry; and a more definitive picture regarding the structures of the glycoproteins is emerging. A role of apolipoproteins in HCV entry has also been established. Still, major questions remain, and the answers to these, which we summarize in this review, will hopefully close the gaps in our understanding and complete the puzzle that is HCV entry.

Association between high-normal levels of alanine aminotransferase and risk factors for atherogenesis.

BACKGROUND & AIMS: Liver disease has been associated with cardiovascular disorders, but little is known about the relationship between serum levels of alanine aminotransferase (ALT) and markers of atherogenesis. We investigated the relationship between low-normal and high-normal levels of ALT and an extended panel of cardiovascular risk factors among individuals with no known diseases in a primary care setting. METHODS: We performed a retrospective analysis of data collected from 6442 asymptomatic patients at wellness visits to a primary care setting in central Virginia from 2010 through 2011. Serum levels of ALT were compared with levels of lipids and lipoproteins, as well as metabolic, inflammatory, and coagulation-related factors associated with risk for cardiovascular disease. RESULTS: Serum levels of ALT were higher than 40 IU/L in 12% of subjects, and in the high-normal range (19-40 IU/L in women and 31-40 IU/L in men) in 25% of subjects. ALT level was associated with the apolipoprotein B level, concentration and particle size of very-low-density lipoproteins, concentration of low-density lipoprotein (LDL) particles (LDL-P), and percentages of small dense LDL (sdLDL) and sdLDL-cholesterol (sdLDL-C) (P < .0001 for all). A high-normal level of ALT was associated with higher levels of LDL-C, LDL-P, sdLDL-C, and sdLDL particles (P < .001 for all). These effects were independent of age, body mass index, and hyperinsulinemia. Increasing levels of ALT and fasting hyperinsulinemia (>12 µU/mL) synergized with increasing levels of triglycerides, very-low-density lipoprotein particles, LDL-P, sdLDL-C, and percentage of sdLDL-C. Levels of APOA1, high-density lipoprotein-cholesterol, and high-density lipoprotein-class 2 were associated inversely with serum level of ALT (P < .0001 for all). CONCLUSIONS: In an analysis of asymptomatic individuals, increased serum levels of ALT (even high-normal levels) are associated with markers of cardiovascular disease.