Dysfunctional HDL and atherosclerotic cardiovascular disease

Therapeutic potential of traditional Chinese medicine against atherosclerosis: Targeting trimethylamine N-oxide

BACKGROUND

Recent studies have shown that plasma trimethylamine-N-oxide (TMAO) level is highly correlated with the risk of atherosclerosis (AS), and the elevated level is significantly positively correlated with the incidence of AS.

PURPOSE

The purpose of this article is to offer a useful summary of the correlation between TMAO and AS, and the effect of herbal monomers, herbal extracts, and formulas on anti-atherosclerosis mediated by TMAO.

METHOD

The data contained in this article comes from PubMed, Web of Science, and China National Knowledge Infrastructure.

RESULTS

This review discusses the main mechanism of AS induced by TMAO, including endothelial dysfunction, macrophage foaming, platelet reactivity, and cholesterol metabolism, and summarizes 6 herb monomers, 5 herb extracts, and 2 formulas that have been tested for their anti-TMAO activity.

CONCLUSION

The current understanding of possible ways to reduce TMAO generation is discussed, with the effect and potential of herb monomers, herb extracts, and formulas highlighted.

Sphingosine-1-Phosphate (S1P) Lyase Inhibition Aggravates Atherosclerosis and Induces Plaque Rupture in ApoE−/− Mice

Altered plasma sphingosine-1-phosphate (S1P) concentrations are associated with clinical manifestations of atherosclerosis. However, whether long-term elevation of endogenous S1P is pro- or anti-atherogenic remains unclear. Here, we addressed the impact of permanently high S1P levels on atherosclerosis in cholesterol-fed apolipoprotein E-deficient (ApoE^−/−) mice over 12 weeks. This was achieved by pharmacological inhibition of the S1P-degrading enzyme S1P lyase with 4-deoxypyridoxine (DOP). DOP treatment dramatically accelerated atherosclerosis development, propagated predominantly unstable plaque phenotypes, and resulted in frequent plaque rupture with atherothrombosis. Macrophages from S1P lyase-inhibited or genetically deficient mice had a defect in cholesterol efflux to apolipoprotein A-I that was accompanied by profoundly downregulated cholesterol transporters ATP-binding cassette transporters ABCA1 and ABCG1. This was dependent on S1P signaling through S1PR3 and resulted in dramatically enhanced atherosclerosis in ApoE^−/−/S1PR3^−/− mice, where DOP treatment had no additional effect. Thus, high endogenous S1P levels promote atherosclerosis, compromise cholesterol efflux, and cause genuine plaque rupture.

Helicobacter pylori infection and DNMT3a polymorphism are associated with the presence of premature coronary artery disease and subclinical atherosclerosis. Data from the GEA Mexican Study

BACKGROUND

The association between H. pylori infection and coronary artery disease (CAD) is well-known. Alterations in DNA methylation in CAD have been reported, which can be induced by H. pylori through the DNA demethylases (DNMTs). The objective was to analyze the association and interaction of H. pylori infection and DMNT3a gene polymorphisms with premature CAD (pCAD) and subclinical atherosclerosis (SA).

METHODS

The study included 561 patients with pCAD, 318 subjects with SA, and 599 healthy controls. Antibodies against H. pylori and DNMT3a rs13420827, rs752208, and rs1550117 polymorphisms were determined.

RESULTS

The pCAD group presented the highest seroprevalence of H. pylori infection (87.7%) compared to the SA (74.5%, p = 1 × 10^-6) and the control group (63.1%, p = 7 × 10^-23). A significant association was observed between H. pylori infection and pCAD (OR = 2.729, p = 1.0 × 10^-6). The rs13420827 polymorphism was associated with a high risk of H. pylori infection in the whole population (p_additive = 0.009, p_dominant = 0.018, and p_codominant2 = 0.013) and in individuals with SA (p_additive = 0.003, p_dominant = 0.020, p_recessive = 0.013, and p_codominant2 = 0.005). The coexistence of H. pylori infection and the rs13420827GG genotype increases the risk of pCAD (p_interaction = 1.1 × 10^-5).

CONCLUSIONS

According to the model adjusted for more confounding variables, H. pylori infection was associated with almost three times the risk of developing pCAD. The rs13420827G allele was associated with an increased risk of H. pylori infection in the whole population and in individuals with SA. Individuals in whom H. pylori infection and the rs13420827GG genotype coexist are at increased risk of pCAD.

Plasma apoM Levels and Progression to Kidney Dysfunction in Patients With Type 1 Diabetes

Apolipoprotein M (apoM), primarily carried by HDL, has been associated with several conditions, including cardiovascular disease and diabetic nephropathy. This study proposes to examine whether plasma apoM levels are associated with the development of diabetic kidney disease, assessed as progression to macroalbuminuria (MA) and chronic kidney disease (CKD). Plasma apoM was measured using an enzyme immunoassay in 386 subjects from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) cohort at DCCT entry and closeout and the concentrations used to determine the association with risk of progression to kidney dysfunction from the time of measurement through 18 years of EDIC follow-up. apoM levels, at DCCT baseline, were higher in patients who developed CKD than in those who retained normal renal function. At DCCT closeout, participants who progressed to MA, CKD, or both MA and CKD also had significantly higher apoM levels than those who remained normal, and increased levels of apoM were associated with increased risk of progression to both MA (risk ratio [RR] 1.30 [95% CI 1.01, 1.66]) and CKD (RR 1.69 [95% CI 1.18, 2.44]). Our results strongly suggest that alterations in apoM and therefore in the composition and function of HDL in type 1 diabetes are present early in the disease process and are associated with the development of nephropathy.

Association between high oxidized high-density lipoprotein levels and increased pericoronary inflammation determined by coronary computed tomography angiography

BACKGROUND

Impaired high-density lipoprotein (HDL) function is a risk factor for cardiac mortality. We aimed to investigate the association between oxidized HDL (oxHDL) and pericoronary adipose tissue (PCAT) attenuation, a novel imaging biomarker of pericoronary inflammation, by using coronary computed tomography angiography (CTA).

METHODS

A total of 287 outpatients with suspected coronary artery disease who had undergone both oxHDL measurement and coronary CTA were examined. PCAT attenuation values were assessed at the proximal 10-50 mm segments of the right coronary artery on coronary CTA. The presence of significant stenosis (luminal narrowing of >50 %) and high-risk plaque characteristics were also evaluated. Patients were then classified into tertiles according to their oxHDL level: low (n = 95), moderate (n = 96), and high (n = 96) groups.

RESULTS

PCAT attenuation in the high oxHDL group was significantly higher than that in other groups after adjusting for age and apolipoprotein-A-I. Multivariate linear regression analysis revealed that oxHDL was significantly associated with PCAT attenuation in the right coronary artery (β = 3.832, p < 0.001), whereas HDL cholesterol was not. Furthermore, subgroup analyses demonstrated that the association between oxHDL and PCAT attenuation remained significant in older patients (β = 6.367, p < 0.001) and in those with hypertension (β = 4.922, p < 0.011), dyslipidemia (β = 3.264, p = 0.010), diabetes mellitus (β = 4.284, p = 0.015), and significant stenosis (β = 3.075, p = 0.021).

CONCLUSIONS

High oxHDL levels were significantly associated with increased pericoronary inflammation, as assessed using coronary CTA. Our results may explain the association between impaired HDL function and the development of coronary atherosclerosis.

MHR and NHR but not LHR were associated with coronary artery disease in patients with chest pain with controlled LDL-C

Several leukocyte to high-density lipoprotein cholesterol (HDL-C) ratios, including monocyte to HDL-C ratio (MHR), neutrophil to HDL-C ratio (NHR) and lymphocyte to HDL-C ratio (LHR), have been proposed as novel inflammatory indicators. We performed a cross-sectional study to investigate the relationships between these leukocyte to HDL-C ratios and coronary artery disease (CAD) in patients with chest pain with controlled low-density lipoprotein cholesterol (LDL-C). A total of 3482 patients with chest pain with LDL-C <1.8 mmol/L were enrolled. We evaluated the relationships between MHR, NHR, LHR and HDL-C and the occurrence of CAD as well as severe stenosis. We found that in patients with chest pain, higher MHR (adjusted OR=2.83, 95% CI 1.61 to 4.99, p<0.001) and NHR (adjusted OR=1.08, 95% CI 1.04 to 1.13, p<0.001), as well as lower HDL-C (adjusted OR=0.53, 95% CI 0.36 to 0.78, p=0.001), but not higher LHR (adjusted OR=1.06, 95% CI 0.94 to 1.20, p=0.341), had a stronger association with the occurrence of CAD. Moreover, unlike LHR (adjusted OR=1.02, 95% CI 0.93 to 1.13, p=0.654), higher MHR (adjusted OR=2.10, 95% CI 1.43 to 3.07, p<0.001) and NHR (adjusted OR=1.06, 95% CI 1.04 to 1.09, p<0.001) and lower HDL-C (adjusted OR=0.38, 95% CI 0.26 to 0.56, p<0.001) were risk factors for severe stenosis. A receiver operating characteristic curve analysis exhibited comparable abilities between MHR and NHR in predicting the presence and severity of CAD. In conclusion, even though patients with chest pain have achieved LDL-C <1.8 mmol/L, the inflammatory indicators MHR and NHR maintained their predictive abilities and remained associated with the occurrence and severity of CAD.

Apolipoprotein A-II, a Player in Multiple Processes and Diseases

Apolipoprotein A-II (apoA-II) is the second most abundant apolipoprotein in high-density lipoprotein (HDL) particles, playing an important role in lipid metabolism. Human and murine apoA-II proteins have dissimilar properties, partially because human apoA-II is dimeric whereas the murine homolog is a monomer, suggesting that the role of apoA-II may be quite different in humans and mice. As a component of HDL, apoA-II influences lipid metabolism, being directly or indirectly involved in vascular diseases. Clinical and epidemiological studies resulted in conflicting findings regarding the proatherogenic or atheroprotective role of apoA-II. Human apoA-II deficiency has little influence on lipoprotein levels with no obvious clinical consequences, while murine apoA-II deficiency causes HDL deficit in mice. In humans, an increased plasma apoA-II concentration causes hypertriglyceridemia and lowers HDL levels. This dyslipidemia leads to glucose intolerance, and the ensuing high blood glucose enhances apoA-II transcription, generating a vicious circle that may cause type 2 diabetes (T2D). ApoA-II is also used as a biomarker in various diseases, such as pancreatic cancer. Herein, we provide a review of the most recent findings regarding the roles of apoA-II and its functions in various physiological processes and disease states, such as cardiovascular disease, cancer, amyloidosis, hepatitis, insulin resistance, obesity, and T2D.

Traffic-related air pollution, biomarkers of metabolic dysfunction, oxidative stress, and CC16 in children

BACKGROUND

Previous research has revealed links between air pollution exposure and metabolic syndrome in adults; however, these associations are less explored in children.

OBJECTIVE

This study aims to investigate the association between traffic-related air pollutants (TRAP) and biomarkers of metabolic dysregulation, oxidative stress, and lung epithelial damage in children.

METHODS

We conducted cross-sectional analyses in a sample of predominantly Latinx, low-income children (n = 218) to examine associations between air pollutants (nitrogen dioxide (NO₂), nitrogen oxides (NO_x), elemental carbon, polycyclic aromatic hydrocarbons, carbon monoxide (CO), fine particulates (PM_2.5)) and biomarkers of metabolic function (high-density lipoprotein (HDL), hemoglobin A1c (HbA1c), oxidative stress (8-isoprostane), and lung epithelial damage (club cell protein 16 (CC16)).

RESULTS

HDL cholesterol showed an inverse association with NO₂ and NO_x, with the strongest relationship between HDL and 3-month exposure to NO₂ (-15.4 mg/dL per IQR increase in 3-month NO₂, 95% CI = -27.4, -3.4). 8-isoprostane showed a consistent pattern of increasing values with 1-day and 1-week exposure across all pollutants. Non-significant increases in % HbA1c were found during 1-month time frames and decreasing CC16 in 3-month exposure time frames.

CONCLUSION

Our results suggest that TRAP is significantly associated with decreased HDL cholesterol in longer-term time frames and elevated 8-isoprostane in shorter-term time frames. TRAP could have the potential to influence lifelong metabolic patterns, through metabolic effects in childhood.

Effect of the ABCA1 agonist CS-6253 on amyloid-β and lipoprotein metabolism in cynomolgus monkeys

BACKGROUND

Inducing brain ATP-binding cassette 1 (ABCA1) activity in Alzheimer's disease (AD) mouse models is associated with improvement in AD pathology. The purpose of this study was to investigate the effects of the ABCA1 agonist peptide CS-6253 on amyloid-β peptides (Aβ) and lipoproteins in plasma and cerebrospinal fluid (CSF) of cynomolgus monkeys, a species with amyloid and lipoprotein metabolism similar to humans.

METHODS

CS-6253 peptide was injected intravenously into cynomolgus monkeys at various doses in three different studies. Plasma and CSF samples were collected at several time points before and after treatment. Levels of cholesterol, triglyceride (TG), lipoprotein particles, apolipoproteins, and Aβ were measured using ELISA, ion-mobility analysis, and asymmetric-flow field-flow fractionation (AF4). The relationship between the change in levels of these biomarkers was analyzed using multiple linear regression models and linear mixed-effects models.

RESULTS

Following CS-6253 intravenous injection, within minutes, small plasma high-density lipoprotein (HDL) particles were increased. In two independent experiments, plasma TG, apolipoprotein E (apoE), and Aβ42/40 ratio were transiently increased following CS-6253 intravenous injection. This change was associated with a non-significant decrease in CSF Aβ42. Both plasma total cholesterol and HDL-cholesterol levels were reduced following treatment. AF4 fractionation revealed that CS-6253 treatment displaced apoE from HDL to intermediate-density- and low density-lipoprotein (IDL/LDL)-sized particles in plasma. In contrast to plasma, CS-6253 had no effect on the assessed CSF apolipoproteins or lipids.

CONCLUSIONS

Treatment with the ABCA1 agonist CS-6253 appears to favor Aβ clearance from the brain.

Prognostic Value of Metabolic Syndrome in Patients With Non-ST Elevated Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Objective

We aim to investigate the prognostic effects of metabolic syndrome (MS) on patients with non-ST elevated myocardial infarction (NSTEMI) after percutaneous coronary intervention (PCI).

Methods

Patients with NSTEMI undergoing PCI were consecutively collected. According to the presence or absence of MS, they were divided into two groups and followed up for 1 year. The endpoint was major adverse cardiovascular events (MACE), including all-cause death, unstable angina hospitalization, heart failure (HF) hospitalization, non-fatal recurrent myocardial infarction (MI), and target lesion revascularization. Also, six subgroups were made according to gender, age, left ventricular ejection fraction (LVEF), Global Registry of Acute Coronary Events (GRACE) score, hypersensitive troponin (hsTNT), and several diseased vessels. Cox proportional hazard model was adopted to analyze the effect of MS on MACE in all the patients and different subgroups.

Results

A total of 1,295 patients were included in the current analysis and 660 (50.97%) of them had MS. About 88 patients were lost to follow-up, and the overall average follow-up was 315 days. MS was an independent risk factor for MACE (HR 1.714, CI 1.265–2.322, p = 0.001), all-cause death, heart failure (HF) hospitalization, and non-fatal recurrent MI. In the MS component, BMI ≥28 kg/m² was positively associated with MACE. Subgroup analysis indicated the prognostic value of MS was more striking for patients with the following: age of >60, LVEF of ≤40%, GRACE of >140, multivessel disease, or hsTNT of >0.1 ng/ml.

Conclusions

The MS was a robust adverse prognostic factor in patients diagnosed with NSTEMI, especially among those of older age and at higher ischemic risk. A BMI of ≥28 kg/m² independently predicted the occurrence of MACE. Prognosis may be improved by controlling abdominal obesity.

The Effects of Eggs in a Plant-Based Diet on Oxidative Stress and Inflammation in Metabolic Syndrome

We recently reported that the inclusion of whole eggs in plant-based diets (PBD) increased plasma choline, lutein, and zeaxanthin in individuals with metabolic syndrome (MetS). The objective of the current study was to evaluate whether this dietary pattern would protect against oxidative stress and low-grade inflammation, two common characteristics of MetS. We recruited 24 men and women with MetS, who, after following a PBD for 2 weeks (baseline), were randomly allocated to consume either two whole eggs with 70 g of spinach/day (EGG) or the equivalent amount of egg substitute with spinach (SUB) as breakfast for 4 weeks. After a 3-week washout, they were allocated to the alternate breakfast. We measured biomarkers of oxidation and inflammation at baseline and at the end of each intervention. Tumor necrosis factor-alpha, interleukin-6, monocyte protein attractant-1, liver enzymes, and C-reactive protein, as well as total antioxidant capacity, paraoxonase-1 (PON-1) activity, and other biomarkers of oxidation were not different at the end of EGG or SUB or when compared to baseline. However, plasma malondialdehyde (MDA) concentrations were lower (p < 0.05) during the EGG and baseline compared to SUB. In addition, the increases in dietary lutein and zeaxanthin previously observed had a strong positive correlation with PON-1 activity (r = 0.522, p < 0.01) only during the EGG period, whereas plasma zeaxanthin was negatively correlated with MDA (r = −0.437, p < 0.01). The number of participants with MetS was reduced from 24 during screening to 21, 13, and 17 during the BL, EGG, and SUB periods, respectively, indicating that eggs were more effective in reversing the characteristics of MetS. These data suggest that adding eggs to a PBD does not detrimentally affect inflammation or oxidative stress; on the contrary, eggs seem to provide additional protection against the biomarkers that define MetS.

High density lipoprotein subfractions and extent of coronary atherosclerotic lesions: From the cordioprev study

BACKGROUND AND AIMS

The extent of atherosclerotic coronary heart disease (CHD) is associated with its prognosis, thus discovering potential biomarkers related to worse outcomes could prove valuable. The present work aims to investigate whether lipoprotein subfractions are associated with angiographic CHD severity.

MATERIALS AND METHODS

Patients from the CORDIOPREV study exhibiting coronary lesions in angiography were classified into two groups (single-vessel coronary disease (SVD) or multivessel coronary disease (MVD)). High-throughput nuclear magnetic resonance (NMR) spectroscopy determined lipoprotein subfractions concentration and composition.

RESULTS

SVD patients showed a higher concentration of medium and small HDL particles compared with MVD patients. For medium HDL, total lipids, phospholipids, total cholesterol, cholesteryl esters and free cholesterol reflected HDL particle concentration, whereas, for small HDL, total lipids, phospholipids, and free cholesterol mirrored lipoprotein particle concentration. Among traditional cardiovascular risk factors, age, hypertension and T2D were independently associated with angiography severity. In multivariate logistic regression models, medium and small HDL particles remained inversely associated with angiography severity (OR 0.77 (95% CI: 0.64-0.91); OR 0.78 (95% CI: 0.67-0.91), respectively) after adjusting with covariates.

CONCLUSION

In CHD patients mostly on statin treatment, angiography severity is inversely related to small and medium HDL subclasses concentration measured by NMR. These particles are also independent predictors of the presence of MVD, and its use increased the prediction of this entity over traditional risk factors.

Deficiency of proline/serine-rich coiled-coil protein 1 (PSRC1) accelerates trimethylamine N-oxide-induced atherosclerosis in ApoE-/- mice

AIMS

The main therapeutic strategies for coronary artery disease (CAD) are mainly based on the correction of abnormal cholesterol levels; however, residual risks remain. The newly proven gut microbial metabolite trimethylamine N-oxide (TMAO) linked with CAD has broadened our horizons. In this study, we determined the role of proline/serine-rich coiled-coil protein 1 (PSRC1) in TMAO-driven atherosclerosis.

METHODS AND RESULTS

We first analyzed the levels of TMAO and PSRC1 in patients with or without atherosclerosis with a target LDL-C < 1.8 mmol/L. Plasma TMAO levels were increased and negatively associated with decreased PSRC1 in peripheral blood mononuclear cells. Animals and in vitro studies showed that TMAO inhibited macrophage PSRC1 expression due to DNA hypermethylation of CpG islands. ApoE^-/- mice fed a choline-supplemented diet exhibited reduced PSRC1 expression accompanied by increased atherosclerotic lesions and plasma TMAO levels. We further deleted PSRC1 in apoE^-/- mice and PSRC1 deficiency significantly accelerated choline-induced atherogenesis, characterized by increased macrophage infiltration, foam cell formation and M1 macrophage polarization. Mechanistically, we overexpressed and knocked out PSRC1 in cultured macrophages to explore the mechanisms underlying TMAO-induced cholesterol accumulation and inflammation. PSRC1 deletion impaired reverse cholesterol transport and enhanced cholesterol uptake and inflammation, while PSRC1 overexpression rescued the proatherogenic phenotype observed in TMAO-stimulated macrophages, which was partially attributed to sulfotransferase 2B1b (SULT2B1b) inhibition.

CONCLUSIONS

Herein, clinical data provide evidence that TMAO may participate in the development of CAD beyond well-controlled LDL-C levels. Our work also suggests that PSRC1 is a negative regulator mediating the unfavorable effects of TMAO-containing diets. Therefore, PSRC1 overexpression and reduced choline consumption may further alleviate atherosclerosis.

A Potential Interplay between HDLs and Adiponectin in Promoting Endothelial Dysfunction in Obesity

Obesity is an epidemic public health problem that has progressively worsened in recent decades and is associated with low-grade chronic inflammation (LGCI) in metabolic tissues and an increased risk of several diseases. In particular, LGCI alters metabolism and increases cardiovascular risk by impairing endothelial function and altering the functions of adiponectin and high-density lipoproteins (HDLs). Adiponectin is an adipokine involved in regulating energy metabolism and body composition. Serum adiponectin levels are reduced in obese individuals and negatively correlate with chronic sub-clinical inflammatory markers. HDLs are a heterogeneous and complex class of lipoproteins that can be dysfunctional in obesity. Adiponectin and HDLs are strictly interdependent, and the maintenance of their interplay is essential for vascular function. Since such a complex network of interactions is still overlooked in clinical settings, this review aims to highlight the mechanisms involved in the impairment of the HDLs/adiponectin axis in obese patients to predict the risk of cardiovascular diseases and activate preventive countermeasures. Here, we provide a narrative review of the role of LGCI in altering HDLs, adiponectin and endothelial functions in obesity to encourage new studies about their synergic effects on cardiovascular health and disease.

Foetal lipoprotein oxidation and preeclampsia

Preeclampsia (PE) is a multisystemic syndrome specific to pregnancy. Although PE is the leading cause of death from complications associated with pregnancy, its aetiology is still unknown. In PE, lipid metabolism is altered. When lipids are damaged, both the mother and the foetus may be at risk. Lipoproteins contain apolipoproteins, triacylglycerols, free and esterified cholesterol, and phospholipids, all of which are susceptible to oxidative stress when high levels of oxygen and nitrogen free radicals are present. Lipoperoxidation can occur in three stages: mild, moderate, and severe. In severe lipid damage, highly toxic products such as malondialdehyde (MDA) can be generated; under these conditions, low-density lipoprotein (LDL) proteins can be oxidized (oxLDL). oxLDL is a biomolecule that can affect the production of nitric oxide (NO), the main vasodilator derived from the endothelium. oxLDL can interfere with the transduction of the signals responsible for triggering the activation of endothelial nitric oxide synthase (eNOS), causing reduced vasodilation and endothelial dysfunction, which are the main characteristics of preeclampsia. The objective of the review was to analyse the information the current information about exists about the impact generated by the oxidation of LDL and HDL lipoproteins in neonates of women with preeclampsia and how these alterations can predispose the neonate to develop diseases in adulthood.

PE can cause foetal loss, intrauterine growth restriction, or developmental complications. Neonates of mothers with PE have a high risk of cardiovascular diseases, stroke, mental retardation, sensory deficiencies and an increased risk of developing metabolic diseases. PE not only affects the foetus, generating complications during pregnancy but also predisposes them to chronic diseases in adulthood.

Lipids and lipoproteins in cardiovascular diseases: a classification

Lipids and lipoproteins, their metabolism, and their transport are essential contributing factors of cardiovascular disease (CVD) as they regulate plasma cholesterol concentration, enhancing cholesterol uptake by macrophages, leading to foam cell formation and ultimately resulting in plaque formation and inflammation. However, lipids and lipoproteins have cardioprotective functions as well, such as preventing oxidation of proatherogenic molecules and downregulating inflammatory proteins.

Associations of body shape index (ABSI) and hip index with liver, metabolic, and inflammatory biomarkers in the UK Biobank cohort

Associations of liver, metabolic, and inflammatory biomarkers in blood with body shape are unclear, because waist circumference (WC) and hip circumference (HC) are dependent on overall body size, resulting in bias. We have used the allometric "a body shape index" (ABSI = WC_(mm)[Formula: see text]Weight_(kg)^-2/3[Formula: see text]Height_(m)^5/6) and hip index (HI_women = HC_(cm)[Formula: see text]Weight_(kg)^-0.482[Formula: see text]Height_(cm)^0.310, HI_men = HC_(cm)[Formula: see text]Weight_(kg)^-2/5[Formula: see text]Height_(cm)^1/5), which are independent of body mass index (BMI) by design, in multivariable linear regression models for 121,879 UK Biobank men and 135,559 women. Glucose, glycated haemoglobin (HbA1c), triglycerides, low-density-lipoprotein cholesterol, apolipoprotein-B, alanine aminotransferase (ALT), gamma-glutamyltransferase, and lymphocytes were associated positively with BMI and ABSI but inversely with HI. High-density-lipoprotein cholesterol and apolipoprotein-A1 were associated inversely with BMI and ABSI but positively with HI. Lipid-related biomarkers and ALT were associated only with HI in obese men. C-reactive protein, neutrophils, monocytes, and alkaline phosphatase were associated positively, while bilirubin was associated inversely, with BMI and ABSI but not with HI. Associations were consistent within the clinical reference ranges but were lost or changed direction for low or high biomarker levels. Our study confirms associations with waist and hip size, independent of BMI, for metabolic biomarkers but only with waist size for inflammatory biomarkers, suggesting different contribution of the mechanistic pathways related to body shape.

Genetic variations in ABCA1/G1 associated with plasma lipid levels and risk of ischemic stroke

BACKGROUND

ATP binding cassette transporters ABCA1 and ABCG1 play a crucial role in cholesterol efflux and reverse cholesterol transport (RCT), thereby rendering ischemic stroke (IS) susceptibility. Variants of ABCA1/G1 have been implicated in etiology of IS. This study aimed to investigate the association between single-nucleotide polymorphisms (SNPs) of ABCA1/G1 with plasma lipid variability and the risk of IS in Chinese Han Population.

METHODS

Totally 249 IS patients and 226 healthy controls were enrolled and 10 SNPs of ABCA1/G1 were screened for genotyping by kompetitive allele-specific polymerase chain reaction (KASP) and validated by sanger sequencing. The logistic regression analysis was performed to identify risk alleles of IS and appropriate genetic model. The genetic risk scores (GRS) and predicted risks for all individuals was computed. Based on different plasma lipid levels, we applied stratified analyses for subgroups. Linkage disequilibrium (LD) test was used to explore different functional haplotype combinations. Association between specific allele or genotype of the SNPs of ABCA1/G1 and plasma lipid or lipoproteins levels were also investigated.

RESULTS

Besides total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), significant differences of clinical data were observed between IS and control group. The rare GG genotype frequencies of rs4149338 on ABCA1 was higher in IS patients than those in controls (11.4%, 4.6%, respectively, P = 0.037). Frequencies of rs57137919 on ABCG1 for rare AA genotype was lower in IS group than those in control group (4.6%, 13.3%, respectively, P = 0.030). GRS showed ability to discriminate IS patients and controls (AUC = 0.633, P < 0.001). Haplotype A-A (rs4149339-rs4149338) was correlated with reduced risk of IS (P = 0.023). Association analysis showed that subjects with rare AA genotype of rs57137919 had the lowest LDL-C levels while rare GG genotype of rs4149338 had lower TC level than those with AA genotype. The mRNA expression of ABCG1 was higher in IS patients, especially in the patients with frequent GG genotype of rs57137919, and was positively correlated with higher ABCG1 expression level and plasma LDL-C level.

CONCLUSIONS

Polymorphisms of ABCA1/G1 associated with varieties of plasma lipid levels and risk of IS.

HDL and Oxidation

In this chapter, we will focus on HDLs' activity of inhibiting LDL oxidation and neutralizing some other oxidants. ApoA-I was known as the main antioxidant component in HDLs. The regulation of antioxidant capacity of HDL is mainly exhibited in regulation of apoA-I and alterations at the level of the HDL lipidome and the modifications of the proteome, especially MPO and PON1. HDL oxidation will influence the processes of inflammation and cholesterol transport, which are important processes in atherosclerosis, metabolic diseases, and many other diseases. In a word, HDL oxidation might be an effective antioxidant target in treatment of many diseases.

New insight into dyslipidemia‐induced cellular senescence in atherosclerosis

Atherosclerosis, characterized by lipid‐rich plaques in the arterial wall, is an age‐related disorder and a leading cause of mortality worldwide. However, the specific mechanisms remain complex. Recently, emerging evidence has demonstrated that senescence of various types of cells, such as endothelial cells (ECs), vascular smooth muscle cells (VSMCs), macrophages, endothelial progenitor cells (EPCs), and adipose‐derived mesenchymal stem cells (AMSCs) contributes to atherosclerosis. Cellular senescence and atherosclerosis share various causative stimuli, in which dyslipidemia has attracted much attention. Dyslipidemia, mainly referred to elevated plasma levels of atherogenic lipids or lipoproteins, or functional impairment of anti‐atherogenic lipids or lipoproteins, plays a pivotal role both in cellular senescence and atherosclerosis. In this review, we summarize the current evidence for dyslipidemia‐induced cellular senescence during atherosclerosis, with a focus on low‐density lipoprotein (LDL) and its modifications, hydrolysate of triglyceride‐rich lipoproteins (TRLs), and high‐density lipoprotein (HDL), respectively. Furthermore, we describe the underlying mechanisms linking dyslipidemia‐induced cellular senescence and atherosclerosis. Finally, we discuss the senescence‐related therapeutic strategies for atherosclerosis, with special attention given to the anti‐atherosclerotic effects of promising geroprotectors as well as anti‐senescence effects of current lipid‐lowering drugs.

The Effect of Hyperlipidemia on the Course of Diabetic Retinopathy—Literature Review

Diabetes mellitus is a very important social issue, and its retinal complications continue to be one of the major causes of blindness worldwide. The effect of glucose level on the development of retinal retinopathy has been the subject of numerous studies and is well understood. Hypertension and hyperlipidemia have been known to be important risk factors in the development of diabetes complications. However, the mechanisms of this effect have not been fully explained and raise a good deal of controversy. The latest research results suggest that some lipoproteins are closely correlated with the incidence of diabetic retinopathy and that by exerting an impact on their level the disease course can be modulated. Moreover, pharmacotherapy which reduces the level of lipids, particularly by means of statins and fibrate, has been shown to alleviate diabetic retinopathy. Therefore, we have decided to review the latest literature on diabetic retinopathy with respect to the impact of hyperlipidemia and possible preventive measures

Associations of HER2 Mutation With Immune-Related Features and Immunotherapy Outcomes in Solid Tumors

Background

HER2 is one of the most extensively studied oncogenes in solid tumors. However, the association between tumor microenvironment (TME) and HER2 mutation remains elusive, and there are no specific therapies for HER2-mutated tumors. Immune checkpoint inhibitors (ICIs) have been approved for some tumor subgroups that lack targeted therapies, while their effects are still unclear in HER2-mutated tumors. We examined whether HER2 mutation impacts treatment outcomes of ICIs in solid tumors via its association with anticancer immunity.

Methods

Multi-omics data of solid tumors from The Cancer Genome Atlas (TCGA), the Asian Cancer Research Group and the Affiliated Hospital of Jiangsu University were used to analyze the association between HER2 mutations and tumor features. Data of patients with multiple microsatellite-stable solid tumors, who were treated by ICIs including antibodies against programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), or cytotoxic T lymphocyte-associated protein 4 (CTLA-4) in eight studies, were collected to investigate the effects of HER2 mutations on immunotherapy outcomes.

Results

The mutation rate of HER2 varied in solid tumors of TCGA, with an overall incidence of 3.13%, ranged from 0.39% to 12.2%. Concurrent HER2 mutations and amplifications were rare (0.26%). HER2 mutation was not associated with HER2 protein expression but was positively associated with microsatellite instability, tumor mutation and neoantigen burdens, infiltrating antitumor immune cells, and signal activities of antitumor immunity. Of 321 ICI-treated patients, 18 carried HER2 mutations (5.6%) and showed improved objective response rates compared with those with HER2 wild-type (44.4% vs. 25.7%, p=0.081), especially in the anti-PD-1/anti-PD-L1 subgroup (62.5% vs. 28.4%, p=0.04). Heterogeneity was observed among tumor types. Patients with HER2 mutations also had superior overall survival than those with HER2 wild-type (HR=0.47, 95%CI: 0.23-0.97, p=0.04), especially in the presence of co-mutations in ABCA1 (HR = 0.23, 95% CI: 0.07-0.73, p=0.013), CELSR1 (HR = 0.24, 95% CI: 0.08-0.77, p=0.016), LRP2 (HR = 0.24, 95% CI: 0.07-0.74, p=0.014), or PKHD1L1 (HR = 0.2, 95% CI: 0.05-0.8, p=0.023).

Conclusions

HER2 mutations may improve the TME to favor immunotherapy. A prospective basket trial is needed to further investigate the impacts of HER2 mutations on immunotherapy outcomes in solid tumors.

High-density lipoprotein lipid peroxidation as a diagnostics biomarker in coronary artery disease

This study aimed at evaluating the serum High-density lipoprotein lipid peroxidation (HDLox) levels and their association with coronary artery disease (CAD). This case-control study comprised 572 patients with stable CAD and 281 healthy subjects with no history of cardiovascular disease (control group). Based on the results of coronary angiography, the patient group was divided into two groups: CAD- and CAD+. HDLox was measured using a fluorimetric method. The ability of HDLox and serum high-density lipoprotein cholesterol (HDL-C) to detect CAD and coronary artery stenosis ≥50% was also compared using the receiver operating characteristic (ROC) curve analysis. The CAD patients showed significantly higher serum HDLox levels, compared to the control group [1.15 (1.01-1.31) vs. 0.85 (0.62-1.06), no units, p < 0.001]. Moreover, serum HDLox levels were significantly lower in CAD- patients, compared to the CAD+ patients [1.05 (0.92-1.22) vs. 1.24 (1.12-1.35), no units, p < 0.001]. According to the results of univariate and multivariate logistic regression, the HDLox showed association with the presence of CAD (odds ratio [OR]: 1.754; 95% confidence interval [CI]: 1.564-1.968; p < 0.001) and coronary artery stenosis ≥50% (OR: 1.729; 95% CI: 1.534-1.949; p < 0.001). The results obtained from the area under the ROC curve revealed that the HDLox could better detect the risk of CAD and coronary artery stenosis ≥50% compared to serum HDL-C level. The oxidation of HDL leads to a reduction in its antioxidant function and it has a crucial role in the development of atherosclerosis. HDLox is suggested as a diagnostics biomarker for CAD.

Cardiovascular Disease in South Asian Immigrants: a Review of Dysfunctional HDL as a Potential Marker

South Asians (SAs) account for a quarter of the world's population and are one of the fastest-growing immigrant groups in the United States (US). South Asian Immigrants (SAIs) are disproportionately more at risk of developing cardiovascular disease (CVD) than other ethnic/racial groups. Atherosclerosis is a chronic inflammatory disorder and is the major cause of CVD. Traditional CVD risk factors, though important, do not fully explain the elevated risk of CVD in SAIs. High-density lipoproteins (HDLs) are heterogeneous lipoproteins that modify their composition and functionality depending on physiological or pathological conditions. With its cholesterol efflux, anti-inflammatory, and antioxidant functions, HDL is traditionally considered a protective factor for CVD. However, its functions can be compromised under pathological conditions, such as chronic inflammation, making it dysfunctional (Dys-HDL). SAIs have a high prevalence of type 2 diabetes and metabolic syndrome, which may further promote Dys-HDL. This review explores the potential association between Dys-HDL and CVD in SAIs and presents current literature discussing the role of Dys-HDL in CVD.

Acute phase protein response and changes in lipoprotein particle size in dogs with systemic inflammatory response syndrome

Background

Improved methodology to measure acute phase proteins and determination of lipoprotein particle‐size distribution (PSD) could be clinically useful in dogs with systemic inflammatory processes.

Objectives

Evaluate an immunoturbidometric assay for serum amyloid A (SAA) and lipoprotein PSD in dogs with sepsis, nonseptic systemic inflammation, and in healthy controls. Correlate dyslipidemic changes with SAA and C‐reactive protein (CRP) concentrations.

Animals

Twenty‐five dogs with sepsis, 15 dogs with nonseptic systemic inflammation, and 22 healthy controls.

Methods

Prospective, case‐control study. Variables included SAA, CRP, and electrophoretic subfractionation of high‐ and low‐density lipoproteins (HDL, LDL). Continuous variables were compared using ANOVA or Kruskal‐Wallis tests with linear regression or Spearman's rank correlation used to assess relationships between variables.

Results

Median SAA and CRP concentrations were greater in dogs with sepsis (SAA 460 mg/L, interquartile range [IQR] 886 mg/L; CRP 133.2 mg/L, IQR 91.6 mg/L) and nonseptic inflammation (SAA 201 mg/L, IQR 436 mg/L; CRP 91.1 mg/L, IQR 88.6 mg/L) compared to healthy dogs (SAA 0.0 mg/L, IQR 0.0 mg/L; CRP 4.9 mg/L, IQR 0.0 mg/L) P < .0001. A cutoff of >677.5 mg/L SAA was 43.2% sensitive and 92.3% specific for sepsis. Low‐density lipoprotein was higher in dogs with sepsis 29.6%, (mean, SD 14.6) compared to 14.4% (mean, SD 5.6) of all lipoproteins in healthy controls (P = .005). High‐density lipoprotein was not associated with CRP but was negatively correlated with SAA (r_s −0.47, P < .0001). Subfractions of LDL and HDL differed between groups (all P < .05).

Conclusions and Clinical Importance

Measurement of SAA using the immunoturbidometric assay evaluated in this study and lipoprotein PSD in dogs with inflammation might help distinguish septic from nonseptic causes of inflammation.

Circular RNA circ_0001445 alleviates the ox-LDL-induced endothelial injury in human primary aortic endothelial cells through regulating ABCG1 via acting as a sponge of miR-208b-5p

BACKGROUND

Coronary artery disease (CAD) originates from the blockage of the inner walls of the coronary arteries due to a plaque buildup. Circular RNA (circRNA) circ_0001445 has been reported to be downregulated in patients with a higher coronary atherosclerotic burden. This study is designed to explore the role and mechanism of circ_0001445 on the oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell damage.

METHODS

Circ_0001445, microRNA-208b-5p (miR-208b-5p), and ATP-binding cassette sub-family G member 1 (ABCG1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Inflammatory cytokines levels, cell viability, proliferation, migration were detected by Enzyme-linked immunosorbent assay (ELISA) kits, Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays, respectively. Protein levels were determined by western blot assay. The binding between miR-208b-5p and circ_0001445 or ABCG1 was predicted by circBank or TargetScan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), and RNA pull-down assays.

RESULTS

Circ_0001445 and ABCG1 were decreased, and miR-208b-5p was increased in CAD patients and ox-LDL-treated HAECs. Also, circ_0001445 overexpression could weaken ox-LDL-triggered HAEC injury by boosting proliferation, migration, and repressing inflammation and extracellular matrix (ECM). Mechanically, circ_0001445 directly targeted miR-208b-5p. Furthermore, miR-208b-5p mediated the modulation of circ_0001445 in ox-LDL-induced HAEC injury. ABCG1 acted as a direct target of miR-208b-5p, and the downregulation of miR-208b-5p relieved ox-LDL-induced HAEC damage by interacting with ABCG1. Additionally, circ_0001445 regulated ABCG1 expression by sponging miR-208b-5p.

CONCLUSION

Circ_0001445 could abate ox-LDL-mediated HAEC damage by the miR-208b-5p/ABCG1 axis, providing a novel insight into the pathogenesis and treatment of CAD.

HDL cholesterol is a protective predictor in the development and progression of retinopathy in type 1 diabetes: A 15-year follow-up study

AIMS

To evaluate the 15-year incidence of development and progression of diabetic retinopathy (DR) in type 1 diabetic patients (T1DM) and determine the associated risk factors.

METHODS

123 T1DM were included in this prospective cohort study and followed for 15 years. Demographic, clinical, laboratory parameters, and retinal photographs were collected and analyzed. Risk factors for DR development and progression were identified using Cox regression analysis.

RESULTS

At baseline, 87 (71%) patients had no DR, and 36 (29%) had nonproliferative DR (NPDR). After 15 years, 54 patients (43.9%; 29.3/1000 person-years) developed NPDR or progressed to proliferative DR (PDR); 24 (27.6%) developed new NPDR, and 30 (83.3%) progressed to PDR. HbA₁c (HR = 1.48, p = 0.008) and urinary albumin excretion rate (AER) (HR = 1.58, p = 0.045) were associated with the risk of DR development and progression, and a protective association was found for HDL cholesterol (HR = 0.17, p = 0.021). The presence of DR at baseline (HR = 2.95, p = 0.023) was associated with the risk of its progression to PDR.

CONCLUSIONS

The 15-year incidence of DR development and progression in T1DM is still very high, which points to the need for close monitoring of T1DM, especially those with higher HbA₁c, higher AER, the initial presence of DR, and lower HDL cholesterol.

Stent-based delivery of AAV2 vectors encoding oxidation-resistant apoA1

In-stent restenosis (ISR) complicates revascularization in the coronary and peripheral arteries. Apolipoprotein A1 (apoA1), the principal protein component of HDL possesses inherent anti-atherosclerotic and anti-restenotic properties. These beneficial traits are lost when wild type apoA1(WT) is subjected to oxidative modifications. We investigated whether local delivery of adeno-associated viral (AAV) vectors expressing oxidation-resistant apoA1(4WF) preserves apoA1 functionality. The efflux of 3H-cholesterol from macrophages to the media conditioned by endogenously produced apoA1(4WF) was 2.1-fold higher than for apoA1(WT) conditioned media in the presence of hypochlorous acid emulating conditions of oxidative stress. The proliferation of apoA1(WT)- and apoA1(4FW)-transduced rat aortic smooth muscle cells (SMC) was inhibited by 66% ± 10% and 65% ± 11%, respectively, in comparison with non-transduced SMC (p < 0.001). Conversely, the proliferation of apoA1(4FW)-transduced, but not apoA1(WT)-transduced rat blood outgrowth endothelial cells (BOEC) was increased 41% ± 5% (p < 0.001). Both apoA1 transduction conditions similarly inhibited basal and TNFα-induced reactive oxygen species in rat aortic endothelial cells (RAEC) and resulted in the reduced rat monocyte attachment to the TNFα-activated endothelium. AAV2-eGFP vectors immobilized reversibly on stainless steel mesh surfaces through the protein G/anti-AAV2 antibody coupling, efficiently transduced cells in culture modeling stent-based delivery. In vivo studies in normal pigs, deploying AAV2 gene delivery stents (GDS) preloaded with AAV2-eGFP in the coronary arteries demonstrated transduction of the stented arteries. However, implantation of GDS formulated with AAV2-apoA1(4WF) failed to prevent in-stent restenosis in the atherosclerotic vasculature of hypercholesterolemic diabetic pigs. It is concluded that stent delivery of AAV2-4WF while feasible, is not effective for mitigation of restenosis in the presence of severe atherosclerotic disease.

LDL particle size and antioxidant HDL function improve after sustained virological response in patients with chronic HCV

HCV infection is associated with an increased incidence of cardiovascular (CV) events. Mechanisms underlying this association remain unknown. In our study, twenty HCV patients (median age 60.5 years, 65% male and 80% with cirrhosis) were evaluated prior, during and after direct-acting antiviral treatment. Ninety percent of patients achieved sustained virological response (SVR). Significant changes were observed in LDL particle size index, measured by LDL-C/apoB ratio, which increased after treatment (p = 0.023). In addition, HDL antioxidant capacity improved gradually from 34.4% at baseline to 42.4% at 4 weeks (p = 0.011), 65.9% at end of treatment EOT (p = 0.002) and remained elevated at 12-week (p = 0.001) after EOT compared to baseline values. Our findings suggest that a shift to a less atherogenic lipid profile may be a possible mechanism associated with CV risk reduction in patients with HCV infection achieving SVR.

Long-term and daily use of molecular hydrogen induces reprogramming of liver metabolism in rats by modulating NADP/NADPH redox pathways

Molecular hydrogen (H₂) has emerged as a new therapeutic option in several diseases and is widely adopted by healthy people. However, molecular data to support therapeutic functions attributed to the biological activities of H₂ remain elusive. Here, using transcriptomic and metabolomic approaches coupled with biochemistry and micro-CT technics, we evaluated the effect of long-term (6 months) and daily use of H₂ on liver function. Rats exposed 2 h daily to H₂ either by drinking HRW (H₂ dissolved in H₂O) or by breathing 4% H₂ gas showed reduced lipogenesis and enhanced lipolysis in the liver, which was associated with apparent loss of visceral fat and brown adipose tissue together with a reduced level of serum lipids. Both transcripts and metabolites enriched in H₂-treated rats revealed alteration of amino acid metabolism pathways and activation of purine nucleotides and carbohydrate biosynthesis pathways. Analysis of the interaction network of genes and metabolites and correlation tests revealed that NADP is the central regulator of H₂ induced metabolic alterations in the liver, which was further confirmed by an increase in the level of components of metabolic pathways that require NADP as substrate. Evidence of immune response regulation activity was also observed in response to exposure to H₂. This work is the first to provide metabolomic and transcriptomic data to uncover molecular targets for the effect of prolonged molecular hydrogen treatment on liver metabolism.

Pig and Mouse Models of Hyperlipidemia and Atherosclerosis

Atherosclerosis is a chronic inflammatory disorder that is the underlying cause of most cardiovascular disease. Resident cells of the artery wall and cells of the immune system participate in atherogenesis. This process is influenced by plasma lipoproteins, genetics, and the hemodynamics of the blood flow in the artery. A variety of animal models have been used to study the pathophysiology and mechanisms that contribute to atherosclerotic lesion formation. No model is ideal as each has its own advantages and limitations with respect to manipulation of the atherogenic process and modeling human atherosclerosis and lipoprotein profile. In this chapter we will discuss pig and mouse models of experimental atherosclerosis. The similarity of pig lipoprotein metabolism and the pathophysiology of the lesions in these animals with that of humans is a major advantage. While a few genetically engineered pig models have been generated, the ease of genetic manipulation in mice and the relatively short time frame for the development of atherosclerosis has made them the most extensively used model. Newer approaches to induce hypercholesterolemia in mice have been developed that do not require germline modifications. These approaches will facilitate studies on atherogenic mechanisms.

Modified Lipoproteins Induce Arterial Wall Inflammation During Atherogenesis

Circulating apolipoprotein B-containing lipoproteins, notably the low-density lipoproteins, enter the inner layer of the arterial wall, the intima, where a fraction of them is retained and modified by proteases, lipases, and oxidizing agents and enzymes. The modified lipoproteins and various modification products, such as fatty acids, ceramides, lysophospholipids, and oxidized lipids induce inflammatory reactions in the macrophages and the covering endothelial cells, initiating an increased leukocyte diapedesis. Lipolysis of the lipoproteins also induces the formation of cholesterol crystals with strong proinflammatory properties. Modified and aggregated lipoproteins, cholesterol crystals, and lipoproteins isolated from human atherosclerotic lesions, all can activate macrophages and thereby induce the secretion of proinflammatory cytokines, chemokines, and enzymes. The extent of lipoprotein retention, modification, and aggregation have been shown to depend largely on differences in the composition of the circulating lipoprotein particles. These properties can be modified by pharmacological means, and thereby provide opportunities for clinical interventions regarding the prevention and treatment of atherosclerotic vascular diseases.

Cardiovascular Effects of Metformin

Type 2 diabetes mellitus is one of the most important independent risk factors for the development, progression and mortality from cardiovascular diseases (CVD). The world communities are faced with the question of developing the optimal management tactics for such comorbidity patients. Thus, the prescribed drug should not only have an adequate hypoglycemic effect, but also have a number of cardioprotective properties, be safe in patients with CVD, and possibly even improve the prognosis and reduce mortality rates. This review is devoted to a representative of the biguanide class - metformin, which is one of the earliest and most effective antihyperglycemic drugs, both as monotherapy and in combination with other antihyperglycemic drugs and insulin; while the evidence base for its cardiovascular profile is only gaining momentum. Thus, the purpose of this review is to highlight the cardiovascular effects of metformin in the context of recent research.

Effects of ABCG1 knockout on proteomic composition of HDL in mice on a chow diet and a High-Fat Diet

ATP-binding cassette transporter G1 (ABCG1) is a cellular transmembrane protein that transports oxysterol efflux from cells to high-density lipoprotein (HDL) particles in the plasma. Previous studies have demonstrated that an ABCG1 deficiency exerts an antiatherosclerotic function through the effects of oxysterol accumulation in cells to enhance apoptosis and regulate inflammatory processes. However, whether the deficiency of ABCG1 and the corresponding changes in the efflux of oxysterols could take a series of impacts on the proteomic composition of HDL remains unclear. Here, plasma HDL of ABCG1(-/-) mice and their wild-type controls on a normal chow diet (NCD) or a high-fat diet (HFD) were isolated by ultracentrifugation. The proportion of 7-ketocholesterol and the proteomic composition of samples were comparatively analyzed by LC-MS/MS. In NCD-fed mice, lipid metabolism-related protein (arachidonate 12-lipoxygenase) and antioxidative protein (pantetheinase) exhibited increased accumulation, and inflammatory response protein (alpha-1-antitrypsin) was decreased in accumulation in ABCG1(-/-) mice HDL. In HFD-fed mice, fewer proteins were detected than that of NCD-fed mice. The ABCG1(-/-) mice HDL exhibited increased accumulation of lipid metabolism-related proteins (e.g., carboxylesterase 1C, apolipoprotein (apo)C-4) and decreased accumulation of alpha-1-antitrypsin, as well as significantly reduced proportion of 7-ketocholesterol. Additionally, positive correlations were found between 7-ketocholesterol and some essential proteins on HDL, such as alpha-1-antitrypsin, apoA-4, apoB-100 and serum amyloid A. These results suggest a detrimental impact of oxysterols on HDL composition, which might affect the antiatherosclerotic properties of HDL. This article is protected by copyright. All rights reserved.

LCAT- targeted therapies: Progress, failures and future

Lecithin: cholesterol acyltransferase (LCAT) is the only enzyme in plasma which is able to esterify cholesterol and boost cholesterol esterify with phospholipid-derived acyl chains. In order to better understand the progress of LCAT research, it is always inescapable that it is linked to high-density lipoprotein (HDL) metabolism and reverse cholesterol transport (RCT). Because LCAT plays a central role in HDL metabolism and RCT, many animal studies and clinical studies are currently aimed at improving plasma lipid metabolism by increasing LCAT activity in order to find better treatment options for familial LCAT deficiency (FLD), fish eye disease (FED), and cardiovascular disease. Recombinant human LCAT (rhLCAT) injections, cells and gene therapy, and small molecule activators have been carried out with promising results. Recently rhLCAT therapies have entered clinical phase II trials with good prospects. In this review, we discuss the diseases associated with LCAT and therapies that use LCAT as a target hoping to find out whether LCAT can be an effective therapeutic target for coronary heart disease and atherosclerosis. Also, probing the mechanism of action of LCAT may help better understand the heterogeneity of HDL and the action mechanism of dynamic lipoprotein particles.

Race and sex differences in HDL peroxide content among American adults with and without type 2 diabetes

Background

High-density lipoprotein (HDL) plays a critical role in protection against atherosclerosic and cardiovascular disease (ASCVD). In addition to contributing to clearing excess vascular cholesterol, HDL particles exhibit antioxidative functions, helping to attenuate adverse effects of oxidized low-density lipoproteins. However, these beneficial properties can be undermined by oxidative stress, inflammation, and unhealthy lifestyles and diet, as well as influenced by race and sex. Thus, when assessing cardiovascular risk, it is important to consider multifactorial aspects of HDL, including antioxidant activity rather than just total amount and type of HDL-cholesterol (HDL-C) particles. Because prior research showed HDL peroxide content (HDLperox) can be inversely associated with normal anti-oxidant HDL activity, elevated HDLperox may serve as a bioindicator of HDL dysfunction.

Methods

In this study, data from a large national cohort of Americans was utilized to determine the impact of sex, race, and diabetes status on HDLperox in middle-aged and older adults. A previously developed cell-free fluorometric method was utilized to quantify HDLperox in serum depleted of apo-B containing lipoproteins.

Results

In keeping with predictions, white men and diabetics exhibited HDLperox in the atypical upper range, suggestive of less functional HDL. White men had higher HDLperox levels than African American males (13.46 ± 6.10 vs. 10.88 ± 5.81, p < .001). There was also a significant main effect of type 2 diabetes (F(1,1901) = 14.9, p < .0001). Overall, African Americans evinced lower HDLperox levels, despite more obesity (10.3 ± 4.7 vs.11.81 ± 5.66 for Whites) suggesting that other aspects of lipid metabolism and psychosocial factors account for the higher prevalence of ASCVD in African Americans.

Conclusion

This research helps to provide a more comprehensive understanding of HDL function in a racially and metabolically diverse adult population. HDLperox content was significantly different in adults with type 2 diabetes, and distinctive in nondiabetic White males, and suggests other processes account for the higher prevalence of ASCVD among African Americans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01608-4.

A New Look at Novel Cardiovascular Risk Biomarkers: The Role of Atherogenic Lipoproteins and Innovative Antidiabetic Therapies

The presence of residual cardiovascular disease (CVD) risk is a current dilemma in clinical practice; indeed, despite optimal management and treatment, a considerable proportion of patients still undergo major CV events. Novel lipoprotein biomarkers are suggested as possible targets for improving the outcomes of patients at higher risk for CVD, and their impact on major CV events and mortality have previously been investigated. Innovative antidiabetic therapies have recently shown a significant reduction in atherogenic lipoproteins, beyond their effects on glucose parameters; it has also been suggested that such anti-atherogenic effect may represent a valuable mechanistic explanation for the cardiovascular benefit of, at least, some of the novel antidiabetic agents, such as glucagon-like peptide-1 receptor agonists. This emphasizes the need for further research in the field in order to clearly assess the effects of innovative treatments on different novel biomarkers, including atherogenic lipoproteins, such as small dense low-density lipoprotein (LDL), lipoprotein(a) (Lp(a)) and dysfunctional high-density lipoprotein (HDL). The current article discusses the clinical importance of novel lipid biomarkers for better management of patients in order to overcome residual cardiovascular risk.

High levels of oxidized fatty acids in HDL impair the antioxidant function of HDL in patients with diabetes

AIMS

Previous studies demonstrate that the antioxidant functions of high-density lipoprotein (HDL) are impaired in diabetic patients. The composition of HDL plays an important role in maintaining the normal functionality of HDL. In this study, we compared the levels of oxidized fatty acids in HDL from diabetic subjects and non-diabetic healthy controls, aiming to investigate the role of oxidized fatty acids in the antioxidant property of HDL.

METHODS

HDL was isolated from healthy subjects (n=6) and patients with diabetes (n=6, hemoglobin A1c ≥ 9%, fasting glucose ≥ 7 mmol/L) using a dextran sulfate precipitation method. Cholesterol efflux capacity mediated by HDL was measured on THP-1 derived macrophages. The antioxidant capacity of HDL was evaluated with dichlorofluorescein-based cellular assay in human aortic endothelial cells. Oxidized fatty acids in HDL were determined by liquid chromatography-tandem mass spectrometry. The correlations between the levels of oxidized fatty acids in HDL and the endothelial oxidant index in cells treated with HDLs were analyzed through Pearson's correlation analyses, and the effects of oxidized fatty acids on the antioxidant function of HDL were verified in vitro.

RESULTS

The cholesterol efflux capacity of HDL and the circulating HDL-cholesterol were similar in diabetic patients and healthy controls, whereas the antioxidant capacity of HDL was significantly decreased in diabetic patients. There were higher levels of oxidized fatty acids in HDL isolated from diabetic patients, which were strongly positively correlated with the oxidant index of cells treated with HDLs. The addition of a mixture of oxidized fatty acids significantly disturbed the antioxidant activity of HDL from healthy controls, while the apolipoprotein A-I mimetic peptide D-4F could restore the antioxidant function of HDL from diabetic patients.

CONCLUSION

HDL from diabetic patients displayed substantially impaired antioxidant activity compared to HDL from healthy subjects, which is highly correlated with the increased oxidized fatty acids levels in HDL.

Different profiles of lipoprotein particles associate various degrees of cardiac involvement in adolescents with morbid obesity

INTRODUCTION

Dyslipidemia secondary to obesity is a risk factor related to cardiovascular disease events, however a pathological conventional lipid profile (CLP) is infrequently found in obese children. The objective is to evaluate the advanced lipoprotein testing (ALT) and its relationship with cardiac changes, metabolic syndrome (MS) and inflammatory markers in a population of morbidly obese adolescents with normal CLP and without type 2 diabetes mellitus, the most common scenario in obese adolescents.

METHODS

Prospective case-control research of 42 morbidly obese adolescents and 25 normal-weight adolescents, whose left ventricle (LV) morphology and function had been assessed. The ALT was obtained by proton nuclear magnetic resonance spectroscopy, and the results were compared according to the degree of cardiac involvement - normal heart, mild LV changes, and severe LV changes (specifically LV remodeling and systolic dysfunction) - and related to inflammation markers [highly-sensitive C-reactive protein and glycoprotein A (GlycA)] and insulin-resistance [homeostatic model assessment for insulin-resistance (HOMA-IR)]. A second analysis was performed to compare our results with the predominant ALT when only body mass index and metabolic syndrome criteria were considered.

RESULTS

The three cardiac involvement groups showed significant increases in HOMA-IR, inflammatory markers and ALT ratio LDL-P/HDL-P (40.0 vs. 43.9 vs. 47.1, p 0.012). When only cardiac change groups were considered, differences in small LDL-P (565.0 vs. 625.1 nmol/L, p 0.070), VLDL size and GlycA demonstrated better utility than just traditional risk factors to predict which subjects could present severe LV changes [AUC: 0.79 (95% CI: 0.54-1)]. In the second analysis, an atherosclerotic ALT was detected in morbidly obese subjects, characterized by a significant increase in large VLDL-P, small LDL-P, ratio LDL-P/HDL-P and ratio HDL-TG/HDL-C. Subjects with criteria for MS presented overall worse ALT (specially in triglyceride-enriched particles) and remnant cholesterol values.

CONCLUSIONS

ALT parameters and GlycA appear to be more reliable indicators of cardiac change severity than traditional CV risk factors. Particularly, the overage of LDL-P compared to HDL-P and the increase in small LDL-P with cholesterol-depleted LDL particles appear to be the key ALT's parameters involved in LV changes. Morbidly obese adolescents show an atherosclerotic ALT and those with MS present worse ALT values.

A Fluorescence-Based In Vitro Method to Assess Cholesterol Efflux

Cholesterol efflux (ChE) capacity is associated with the incidence of cardiovascular events and has been proposed as an emerging cardiovascular risk factor. ChE has been traditionally assessed by in vitro radioactive methods but these are not appropriate when assessing a large number of samples. Therefore, alternative, reproducible nonradioactive methods have been developed. This chapter describes a robust nonradioactive method using a fluorescent tracer to assess ChE in vitro.The measurement of ChE in vitro requires three main components: a cholesterol-loaded donor cell, a cholesterol tracer, and a cholesterol acceptor. This method involves labeling of murine macrophage J774A.1 cells using the fluorescent sterol dipyrromethene boron difluoride (BODIPY)-cholesterol. The cholesterol acceptors from humans or animals include lipid-free apolipoprotein (ApoA)-1, high-density lipoprotein (HDL), HDL₂ and HDL₃ subfractions, serum, plasma or ApoB-depleted serum or plasma. While lipid-free ApoA-1 mediates ChE via only ATP-binding cassette (ABC)A1 transporter, the remaining acceptors mediate ChE via ABCA1 , ABCG1 and scavenger receptor class B type 1 (SRB1) transporters. The reproducibility of this BODIPY-ChE assay is excellent as the intra-assay coefficients of variation (CVs) were <10% (30 replicates on the same day) and the interassay CVs were <14% (10 experiments performed on different days, with 3 replicates each). The fluorescent method therefore represents a reproducible, safe and useful tool to evaluate ChE as an emerging cardiovascular risk factor.

The value of HDL subfractions in predicting cardiovascular outcomes in untreated, diabetic patients with stable coronary artery disease: An age- and gender-matched case-control study

OBJECTIVE

The aim of the present study was to examine the value of high-density lipoprotein (HDL) subfractions for predicting cardiovascular events (CVEs) in untreated type 2 diabetes mellitus (T2DM) patients with stable coronary artery disease (SCAD) using an age- and gender-matched case-control study.

METHODS

In total, 185 SCAD patients and 185 T2DM patients with SCAD were enrolled and subjected to a clinical follow-up of CVEs. HDL subfractions were analyzed using the Quantimetrix Lipoprint System. The relationship between HDL subfractions and CVEs in T2DM patients with SCAD was evaluated by Kaplan-Meier analysis and Cox proportional hazard models.

RESULTS

During a median 37.7-month follow-up, T2DM patients with SCAD had a higher percentage of CVEs compared to SCAD patients (p=0.039). The concentration of the combined intermediate and small HDL-C subfraction (defined as the mixed HDL subfraction) was related to the event incidence in T2DM patients with SCAD (p=0.004), and it was positively associated with increased CVEs even after adjustment in three models. Kaplan-Meier curve analysis indicated that T2DM patients with SCAD in the high mixed HDL subfraction group (>28 mg/dL) had lower event-free survival rates (p=0.008).

CONCLUSIONS

Elevated concentration of the mixed HDL subfraction concentration predicts events in T2DM patients with SCAD.

TCM Regulates PI3K/Akt Signal Pathway to Intervene Atherosclerotic Cardiovascular Disease

Vascular endothelial injury is the initial stage of atherosclerosis (AS). Stimulating and activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway can regulate the expression of vascular endothelial cytokines, thus affecting the occurrence and development of AS. In addition, the PI3K/Akt signaling pathway can regulate the polarization and survival of macrophages and the expression of inflammatory factors and platelet function, thus influencing the progression of AS. In recent years, traditional Chinese medicine (TCM) has been widely recognized for its advantages of fewer side effects, multiple pathways, and multiple targets. Also, the research of TCM regulation of AS via the PI3K/Akt signaling pathway has achieved certain results. This study aimed to analyze the characteristics of the PI3K/Akt signaling pathway and its role in the pathogenesis of AS, as well as the role of Chinese medicine in regulating the PI3K/Akt signaling pathway. The findings are expected to provide a theoretical basis for the clinical treatment and pathological mechanism research of AS.

Modification of High-Density Lipoprotein Functions by Diet and Other Lifestyle Changes: A Systematic Review of Randomized Controlled Trials

High-density lipoprotein (HDL) functional traits have emerged as relevant elements that may explain HDL antiatherogenic capacity better than HDL cholesterol levels. These properties have been improved in several lifestyle intervention trials. The aim of this systematic review is to summarize the results of such trials of the most commonly used dietary modifications (fatty acids, cholesterol, antioxidants, alcohol, and calorie restriction) and physical activity. Articles were screened from the Medline database until March 2021, and 118 randomized controlled trials were selected. Results from HDL functions and associated functional components were extracted, including cholesterol efflux capacity, cholesteryl ester transfer protein, lecithin-cholesterol acyltransferase, HDL antioxidant capacity, HDL oxidation status, paraoxonase-1 activity, HDL anti-inflammatory and endothelial protection capacity, HDL-associated phospholipase A2, HDL-associated serum amyloid A, and HDL-alpha-1-antitrypsin. In mainly short-term clinical trials, the consumption of monounsaturated and polyunsaturated fatty acids (particularly omega-3 in fish), and dietary antioxidants showed benefits to HDL functionality, especially in subjects with cardiovascular risk factors. In this regard, antioxidant-rich dietary patterns were able to improve HDL function in both healthy individuals and subjects at high cardiovascular risk. In addition, in randomized trial assays performed mainly in healthy individuals, reverse cholesterol transport with ethanol in moderate quantities enhanced HDL function. Nevertheless, the evidence summarized was of unclear quality and short-term nature and presented heterogeneity in lifestyle modifications, trial designs, and biochemical techniques for the assessment of HDL functions. Such findings should therefore be interpreted with caution. Large-scale, long-term, randomized, controlled trials in different populations and individuals with diverse pathologies are warranted.

Genomic Variants and Multilevel Regulation of ABCA1, ABCG1, and SCARB1 Expression in Atherogenesis

Atheroprotective properties of human plasma high-density lipoproteins (HDLs) are determined by their involvement in reverse cholesterol transport (RCT) from the macrophage to the liver. ABCA1, ABCG1, and SR-BI cholesterol transporters are involved in cholesterol efflux from macrophages to lipid-free ApoA-I and HDL as a first RCT step. Molecular determinants of RCT efficiency that may possess diagnostic and therapeutic meaning remain largely unknown. This review summarizes the progress in studying the genomic variants of ABCA1, ABCG1, and SCARB1, and the regulation of their function at transcriptional and post-transcriptional levels in atherosclerosis. Defects in the structure and function of ABCA1, ABCG1, and SR-BI are caused by changes in the gene sequence, such as single nucleotide polymorphism or various mutations. In the transcription initiation of transporter genes, in addition to transcription factors, long noncoding RNA (lncRNA), transcription activators, and repressors are also involved. Furthermore, transcription is substantially influenced by the methylation of gene promoter regions. Post-transcriptional regulation involves microRNAs and lncRNAs, including circular RNAs. The potential biomarkers and targets for atheroprotection, based on molecular mechanisms of expression regulation for three transporter genes, are also discussed in this review.

High-Sensitivity C-Reactive Protein to HDL-C Ratio

Inflammation and lipid signaling are involved in the pathogenesis and progression of coronary artery disease (CAD). We proposed that high-sensitivity C-reactive proteins, as a marker of the pro-inflammatory state, and high-density lipoprotein cholesterol (HDL-C), as an anti-atherosclerosis component, should be integrated into a single novel biomarker. Our work was conducted to discuss and compare the predictive ability of the high-sensitivity C-reactive protein to high-density lipoprotein cholesterol ratio (CHR) with other existing indices, for example, neutrophil high-density lipoprotein ratio (NHR) and neutrophil lymphocyte ratio (NLR), in the severity of CAD patients.Based on the results of coronary angiography, patients were divided into the CAD⁺ group, CAD^- group, and control group. The relationship between various serum markers and the severity of coronary artery disease was examined via Spearman's correlation analysis. Logistic regression analysis was conducted to identify the influencing factors of the coronary artery disease severity.This study included 420 patients. The Gensini score was positively correlated with CHR. Multiple regression analysis revealed that the CHR was significantly associated with CAD. CHR is an independent predictor of CAD. The receiver operating characteristic (ROC) analysis provided a cut-off value of 1.17 for CHR to predict CAD, with a specificity of 86.7%, Yoden index of 0.264, and area under the ROC curve of 0.662 (95% confidence intervals 0.606-0.719, P < 0.001). At the same time, the area under the ROC curve of the NHR was 0.652, and that of the NLR was 0.579. The results of the DeLong test indicated that the area under the ROC curve of the CHR was larger than that of the NLR (P = 0.0306). This suggests that the CHR as a predictor of CAD has better diagnostic performance than the NLR.CHR was not only closely related to the presence and severity of CAD but also an independent predictor of severe CAD.

High-density lipoprotein cholesterol to apolipoprotein A1 ratio and all-cause mortality among incident peritoneal dialysis patients

BACKGROUND AND AIMS

The ratio of high-density lipoprotein cholesterol to apolipoprotein A1 (HAR) is associated with all-cause mortality in nonchronic kidney disease patients, but its role in predicting all-cause mortality in patients undergoing peritoneal dialysis (PD) is still unclear. The purpose of this study was to investigate the relationship between HAR and all-cause mortality in patients with PD.

METHODS AND RESULTS

The medical records of 1199 patients with PD from November 1, 2005, to August 31, 2019, were collected retrospectively. The main outcome was defined as all-cause mortality. The HAR was divided into three groups by X-tile software. The association between HAR and all-cause mortality was evaluated by Cox models. The Kaplan-Meier method was used for the survival curve. The median follow-up period was 35 months (interquartile range: 20-57 months), with a total of 326 deaths recorded. After multiple adjustments, the risk of all-cause mortality in the high HAR group was 1.96-fold higher than that in the low HAR group (hazard ratio: 1.96; 95% CI, 1.22 to 3.15; P = 0.005). The restricted cubic splines showed that the risk of all-cause mortality increased gradually when HAR was >0.37. In the stratified analysis, a high HAR was linked to a high risk of all-cause mortality in males, patients under 55 years old, and patients without diabetes or cardiovascular disease (CVD).

CONCLUSION

This study suggests that HAR is independently related to all-cause mortality in PD patients, especially in males, patients under 55 years old, and patients without diabetes or CVD.

Gene Therapy for Cardiovascular Disease: Basic Research and Clinical Prospects

In recent years, the vital role of genetic factors in human diseases have been widely recognized by scholars with the deepening of life science research, accompanied by the rapid development of gene-editing technology. In early years, scientists used homologous recombination technology to establish gene knock-out and gene knock-in animal models, and then appeared the second-generation gene-editing technology zinc-finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) that relied on nucleic acid binding proteins and endonucleases and the third-generation gene-editing technology that functioned through protein-nucleic acids complexes-CRISPR/Cas9 system. This holds another promise for refractory diseases and genetic diseases. Cardiovascular disease (CVD) has always been the focus of clinical and basic research because of its high incidence and high disability rate, which seriously affects the long-term survival and quality of life of patients. Because some inherited cardiovascular diseases do not respond well to drug and surgical treatment, researchers are trying to use rapidly developing genetic techniques to develop initial attempts. However, significant obstacles to clinical application of gene therapy still exists, such as insufficient understanding of the nature of cardiovascular disease, limitations of genetic technology, or ethical concerns. This review mainly introduces the types and mechanisms of gene-editing techniques, ethical concerns of gene therapy, the application of gene therapy in atherosclerosis and inheritable cardiovascular diseases, in-stent restenosis, and delivering systems.