High-Density Lipoprotein (HDL) Triglyceride and Oxidized HDL: New Lipid Biomarkers of Lipoprotein-Related Atherosclerotic Cardiovascular Disease

Mitigating Vascular Inflammation by Mimicking AIBP Mechanisms: A New Therapeutic End for Atherosclerotic Cardiovascular Disease

Atherosclerosis, characterized by the accumulation of lipoproteins and lipids within the vascular wall, underlies a heart attack, stroke, and peripheral artery disease. Endothelial inflammation is the primary component driving atherosclerosis, promoting leukocyte adhesion molecule expression (e.g., E-selectin), inducing chemokine secretion, reducing the production of nitric oxide (NO), and enhancing the thrombogenic potential. While current therapies, such as statins, colchicine, anti-IL1β, and sodium-glucose cotransporter 2 (SGLT2) inhibitors, target systemic inflammation, none of them addresses endothelial cell (EC) inflammation, a critical contributor to disease progression. Targeting endothelial inflammation is clinically significant because it can mitigate the root cause of atherosclerosis, potentially preventing disease progression, while reducing the side effects associated with broader anti-inflammatory treatments. Recent studies highlight the potential of the APOA1 binding protein (AIBP) to reduce systemic inflammation in mice. Furthermore, its mechanism of action also guides the design of a potential targeted therapy against a particular inflammatory signaling pathway. This review discusses the unique advantages of repressing vascular inflammation or enhancing vascular quiescence and the associated benefits of reducing thrombosis. This approach offers a promising avenue for more effective and targeted interventions to improve patient outcomes.

The Association of the Cholesterol Efflux Capacity with the Paraoxonase 1 Q192R Genotype and the Paraoxonase Activity

AIMS

Paraoxonase 1 (PON1) binds to high-density lipoprotein (HDL) and protects against atherosclerosis. However, the relationship between functional PON1 Q192R polymorphism, which is associated with the hydrolysis of paraoxon (POXase activity) and atherosclerotic cardiovascular disease (ASCVD), remains controversial. As the effect of PON1 Q192R polymorphism on the HDL function is unclear, we investigated the relationship between this polymorphism and the cholesterol efflux capacity (CEC), one of the biological functions of HDL, in association with the PON1 activity.

METHODS

The relationship between PON1 Q192R polymorphisms and CEC was investigated retrospectively in 150 subjects without ASCVD (50 with the PON1 Q/Q genotype, 50 with the Q/R genotype, and 50 with the R/R genotype) who participated in a health screening program. The POXase and arylesterase (AREase: hydrolysis of aromatic esters) activities were used as measures of the PON1 activity.

RESULTS

The AREase activity was positively correlated with CEC independent of the HDL cholesterol levels. When stratified by the PON1 Q192R genotype, the POXase activity was also positively correlated with CEC independent of HDL cholesterol. PON1 Q192R R/R genotype carriers had a lower CEC than Q/Q or Q/R genotype carriers, despite having a higher POXase activity. Moreover, in a multiple regression analysis, the PON1 Q192R genotype was associated with the degree of CEC, independent of the HDL cholesterol and POXase activity.

CONCLUSIONS

The PON1 Q192R R allele is associated with reduced CEC in Japanese people without ASCVD. Further studies on the impact of this association on the severity of atherosclerosis and ASCVD development are thus called for.

Short-term HIIT impacts HDL function differently in lean, obese, and diabetic subjects

Introduction

High density lipoproteins (HDL) exert cardiovascular protection in part through their antioxidant capacity and cholesterol efflux function. Effects of exercise training on HDL function are yet to be well established, while impact on triacylglycerol (TG)-lowering has been often reported. We previously showed that a short-term high-intensity interval training (HIIT) program improves insulin sensitivity but does not inhibit inflammatory pathways in immune cells in insulin-resistant subjects. The purpose of this study is to evaluate HDL function along with changes of lipoproteins after the short-term HIIT program in lean, obese nondiabetic, and obese type 2 diabetic (T2DM) subjects.

Methods

All individuals underwent a supervised 15-day program of alternative HIIT for 40 minutes per day. VO2peak was determined before and after this training program. A pre-training fasting blood sample was collected, and the post-training fasting blood sample collection was performed 36 hours after the last exercise session.

Results

Blood lipid profile and HDL function were analyzed before and after the HIIT program. Along with improved blood lipid profiles in obese and T2DM subjects, the HIIT program affected circulating apolipoprotein amounts differently. The HIIT program increased HDL-cholesterol levels and improved the cholesterol efflux capacity only in lean subjects. Furthermore, the HIIT program improved the antioxidant capacity of HDL in all subjects. Data from multiple logistic regression analysis showed that changes in HDL antioxidant capacity were inversely associated with changes in atherogenic lipids and changes in HDL-TG content.

Discussion

We show that a short-term HIIT program improves aspects of HDL function depending on metabolic contexts, which correlates with improvements in blood lipid profile. Our results demonstrate that TG content in HDL particles may play a negative role in the anti-atherogenic function of HDL.

Pharmacological characterization of the antidiabetic drug metformin in atherosclerosis inhibition: A comprehensive insight

BACKGROUND

Atherosclerosis (AS) is a progressive disease that interferes with blood flow, leading to cardiovascular complications such as hypertension, ischemic heart disease, ischemic stroke, and vascular ischemia. The progression of AS is correlated with inflammation, oxidative stress, and endothelial dysfunction. Various signaling pathways, like nuclear erythroid-related factor 2 (Nrf2) and Kruppel-like factor 2 (KLF2), are involved in the pathogenesis of AS. Nrf2 and KLF2 have anti-inflammatory and antioxidant properties. Thus, activation of these pathways may reduce the development of AS. Metformin, an insulin-sensitizing drug used in the management of type 2 diabetes mellitus (T2DM), increases the expression of Nrf2 and KLF2. AS is a common long-term macrovascular complication of T2DM. Thus, metformin, through its pleiotropic anti-inflammatory effect, may attenuate the development and progression of AS.

AIMS

Therefore, this review aims to investigate the possible role of metformin in AS concerning its effect on Nrf2 and KLF2 and inhibition of reactive oxygen species (ROS) formation. In addition to its antidiabetic effect, metformin can reduce cardiovascular morbidities and mortalities compared to other antidiabetic agents, even with similar blood glucose control by the Nrf2/KLF2 pathway activation.

CONCLUSION

In conclusion, metformin is an effective therapeutic strategy against the development and progression of AS, mainly through activation of the KLF2/Nrf2 axis.

Possible role of LCZ696 in atherosclerosis: new inroads and perspective

LCZ696 blocks both angiotensin receptor type 1 (ATR1) and neprilysin (NEP), which are intricate in the degradation of natriuretic peptides (NPs) and other endogenous peptides. It has been shown NEP inhibitors and LCZ696 could be effectively in the management of atherosclerosis (AS). However, the underlying mechanism of LCZ696 in AS is needed to be clarified entirely. Hence, this review is directed to reconnoiter the mechanistic role of LCZ696 in AS. The anti-inflammatory role of LCZ696 is related to the inhibition of transforming growth factor beta (TGF-β)-activated kinase 1 (TAK) and nod-like receptor pyrin 3 receptor (NLRP3) inflammasome. Moreover, LCZ696, via inhibition of pro-inflammatory cytokines, oxidative stress, apoptosis and endothelial dysfunction can attenuate the development and progression of AS. In conclusion, LCZ696 could be effective in the management of AS through modulation of inflammatory and oxidative signaling. Preclinical and clinical studies are recommended in this regard.

High-density lipoprotein metrics during midlife and future subclinical atherosclerosis in women: the SWAN HDL study

OBJECTIVE

The clinical utility of high-density lipoprotein cholesterol (HDL-C) in risk classification is limited, especially in midlife women. Novel metrics of HDL may better reflect this risk. We clustered a comprehensive profile of HDL metrics into favorable and unfavorable clusters and assessed how these two clusters are related to future subclinical atherosclerosis (carotid intima media thickness [cIMT], interadventitial diameter [IAD], and carotid plaque presence) in midlife women.

METHODS

Four hundred sixty-one women (baseline age: 50.4 [2.7] years; 272 White, 137 Black, 52 Chinese) from the Study of Women's Health Across the Nation HDL ancillary study who had baseline measures of HDL cholesterol efflux capacity (HDL-CEC), lipid contents (HDL-phospholipids [HDL-PL] and HDL triglycerides [HDL-Tg]), and HDL particle (HDL-P) distribution and size, followed by carotid ultrasound (average 12.9 [SD: 2.6] years later), were included. Using latent cluster analysis, women were clustered into a favorable (high HDL-CEC, HDL-PL, large and medium HDL-P, less HDL-Tg and small HDL-P, larger size) or an unfavorable HDL cluster (low HDL-CEC, HDL-PL, large and medium HDL-P, more HDL-Tg, and small HDL-P, smaller size) and then linked to future subclinical atherosclerosis using linear or logistic regression.

RESULTS

The favorable HDL cluster was associated with lower cIMT, IAD, and odds of carotid plaque presence. These associations were attenuated by body mass index, except in Chinese women where the association with cIMT persisted (0.72 [0.63, 0.83]).

CONCLUSIONS

The association between favorable HDL clusters and a better postmenopausal subclinical atherosclerosis profile is largely explained by body mass index; however, racial/ethnic differences may exist.

Increased thyroid stimulating hormone (TSH) as a possible risk factor for atherosclerosis in subclinical hypothyroidism

Primary hypothyroidism (PHT) is associated with an increased risk for the development of atherosclerosis (AS) and other cardiovascular disorders. PHT induces atherosclerosis (AS) through the induction of endothelial dysfunction, and insulin resistance (IR). PHT promotes vasoconstriction and the development of hypertension. However, patients with subclinical PHT with normal thyroid hormones (THs) are also at risk for cardiovascular complications. In subclinical PHT, increasing thyroid stimulating hormone (TSH) levels could be one of the causative factors intricate in the progression of cardiovascular complications including AS. Nevertheless, the mechanistic role of PHT in AS has not been fully clarified in relation to increased TSH. Therefore, in this review, we discuss the association between increased TSH and AS, and how increased TSH may be involved in the pathogenesis of AS. In addition, we also discuss how L-thyroxine treatment affects the development of AS.

Lutein and Zeaxanthin Enhance, Whereas Oxidation, Fructosylation, and Low pH Damage High-Density Lipoprotein Biological Functionality

High-density lipoproteins (HDLs) are key regulators of cellular cholesterol homeostasis but are functionally altered in many chronic diseases. The factors that cause HDL functional loss in chronic disease are not fully understood. It is also unknown what roles antioxidant carotenoids play in protecting HDL against functional loss. The aim of this study was to measure how various disease-associated chemical factors including exposure to (1) Cu2+ ions, (2) hypochlorous acid (HOCL), (3) hydrogen peroxide (H2O2), (4) sialidase, (5) glycosidase, (6) high glucose, (7) high fructose, and (8) acidic pH, and the carotenoid antioxidants (9) lutein and (10) zeaxanthin affect HDL functionality. We hypothesized that some of the modifications would have stronger impacts on HDL particle structure and function than others and that lutein and zeaxanthin would improve HDL function. HDL samples were isolated from generally healthy human plasma and incubated with the corresponding treatments listed above. Cholesterol efflux capacity (CEC), lecithin-cholesterol acyl transferase (LCAT) activity, and paraoxonase-1 (PON1) activity were measured in order to determine changes in HDL functionality. Median HDL particle diameter was increased by acidic pH treatment and reduced by HOCl, high glucose, high fructose, N-glycosidase, and lutein treatments. Acidic pH, oxidation, and fructosylation all reduced HDL CEC, whereas lutein, zeaxanthin, and sialidase treatment improved HDL CEC. LCAT activity was reduced by acidic pH, oxidation, high fructose treatments, and lutein. PON1 activity was reduced by sialidase, glycosidase, H2O2, and fructose and improved by zeaxanthin and lutein treatment. These results show that exposure to oxidizing agents, high fructose, and low pH directly impairs HDL functionality related to cholesterol efflux and particle maturation, whereas deglycosylation impairs HDL antioxidant capacity. On the other hand, the antioxidants lutein and zeaxanthin improve or preserve both HDL cholesterol efflux and antioxidant activity but have no effect on particle maturation.

High ADMA Is Associated with Worse Health Profile in Heart Failure Patients Hospitalized for Episodes of Acute Decompensation

Background and Objectives: episodes of acute decompensation in chronic heart failure (ADHF), a common health problem for the growing elderly population, pose a significant socio-economic burden on the public health systems. Limited knowledge is available on both the endothelial function in and the cardio-metabolic health profile of old adults hospitalized due to ADHF. This study aimed to investigate the connection between asymmetric dimethylarginine (ADMA)-a potent inhibitor of nitric oxide-and key health biomarkers in this category of high-risk patients. Materials and Methods: this pilot study included 83 individuals with a known ADHF history who were admitted to the ICU due to acute cardiac decompensation. Selected cardiovascular, metabolic, haemogram, renal, and liver parameters were measured at admission to the ICU. Key renal function indicators (serum creatinine, sodium, and potassium) were determined again at discharge. These parameters were compared between patients stratified by median ADMA (114 ng/mL). Results: high ADMA patients showed a significantly higher incidence of ischemic cardiomyopathy and longer length of hospital stay compared to those with low ADMA subjects. These individuals exhibited significantly higher urea at admission and creatinine at discharge, indicating poorer renal function. Moreover, their lipid profile was less favorable, with significantly elevated levels of total cholesterol and HDL. However, no significant inter-group differences were observed for the other parameters measured. Conclusions: the present findings disclose multidimensional, adverse ADMA-related changes in the health risk profile of patients with chronic heart failure hospitalized due to recurrent decompensation episodes.

Yerba Mate as a Protectant against Lipoproteins Oxidation

Oxidative modification of low-density lipoproteins (LDL) and high-density lipoproteins (HDL) are important factors determining cardiovascular risk. This study investigated the antioxidant mechanisms and potential protective effect of a hydroethanolic extract of yerba mate (Ilex paraguaiensis; EHEM) on the in vitro oxidation of LDL and HDL. EHEM was found to possess ferric reducing power, DPPH free radical scavenging capacity, metal chelating activity, and NO radical scavenging activity. In addition, EHEM reduced the lipoperoxidation induced by α,α'-Azodiisobutyramidine dihydrochloride (AAPH) in HDL and LDL at all tested concentrations. In this study, we demonstrate the antioxidant properties of yerba mate and its phytochemical compounds. These properties may effectively prevent the in vitro oxidation of LDL and HDL molecules, a phenomenon linked to the pathogenesis of atherosclerosis.

Beeswax Alcohol Prevents Low-Density Lipoprotein Oxidation and Demonstrates Antioxidant Activities in Zebrafish Embryos and Human Subjects: A Clinical Study

Oxidative stress is one of the primary instigators of the onset of various human ailments, including cancers, cardiovascular diseases, and dementia. Particularly, oxidative stress severely affects low-density lipid & protein (LDL) oxidation, leading to several detrimental health effects. Therefore, in this study, the effect of beeswax alcohol (BWA) was evaluated in the prevention of LDL oxidation, enhancement of paraoxonase 1 (PON-1) activity of high-density lipid & protein (HDL), and zebrafish embryo survivability. Furthermore, the implication of BWA consumption on the oxidative plasma variables was assessed by a preliminary clinical study on middle-aged and older human subjects (n = 50). Results support BWA augmentation of PON-1 activity in a dose-dependent manner (10-30 μM), which was significantly better than the effect exerted by coenzyme Q10 (CoQ10). Moreover, BWA significantly curtails LDL/apo-B oxidation evoked by CuSO4 (final 0.5 μM) and a causes a marked reduction in lipid peroxidation in LDL. The transmission electron microscopy (TEM) analysis revealed a healing effect of BWA towards the restoration of LDL morphology and size impaired by the exposure of Cu2+ ions (final 0.5 μM). Additionally, BWA counters the toxicity induced by carboxymethyllysine (CML, 500 ng) and rescues zebrafish embryos from development deformities and apoptotic cell death. A completely randomized, double-blinded, placebo-controlled preliminary clinical study on middle- and older-aged human subjects (n = 50) showed that 12 weeks of BWA (100 mg/day) supplementation efficiently diminished serum malondialdehyde (MDA) and total hydroperoxides and enhanced total antioxidant status by 25%, 27%, and 22%, respectively, compared to the placebo-control and baseline values. Furthermore, the consumption of BWA did not exhibit any noteworthy changes in physical variables, lipid profile, glucose levels, and biomarkers pertinent to kidney and liver function, thus confirming the safety of BWA for consumption. Conclusively, in vitro, BWA prevents LDL oxidation, enhances PON-1 activity in HDL, and positively influences oxidative variables in human subjects.

Application of serum Raman spectroscopy in rapid and early discrimination of aplastic anemia and myelodysplastic syndrome

BACKGROUND

Raman spectroscopy of hematological diseases has gained attention from various researchers. However, serum analysis of bone marrow failure (BMF), represented by aplastic anemia (AA) and myelodysplastic syndromes (MDS) has not been fully investigated. In this study, we aimed at establishing a simple, non-invasive serum detection method for AA and MDS.

METHOD

Serum samples from 35 AA patients (N = 35), MDS patients (N = 25), and control volunteers (N = 23) were systematically analyzed via laser Raman spectroscopy, and orthogonal partial least squares discrimination analysis (OPLS-DA). Then, discrimination models between the BMFs and control were constructed and evaluated using the prediction set.

RESULTS

Compared to control volunteers, serum spectral data for BMF patients were specific. The intensities of Raman peaks representing nucleic acids (726, 781, 786, 1078, 1190, 1415 cm-1), proteins (1221 cm-1), phospholipid/cholesterol (1285 cm-1), and β-carotene (1162 cm-1) significantly decreased, while the intensity of lipids (1437 and 1446 cm-1) significantly increased. Intensities of Raman peaks representing nucleic acids (726 cm-1) and collagen (1344 cm-1) in the AA group were significantly lower than in the control group. Intensities of Raman peaks representing nucleic acids (726 and 786 cm-1), proteins (1003 cm-1), and collagen (1344 cm-1) in the MDS group were significantly lower than those of the control group. The intensity of Raman peaks representing lipids (1437 and 1443 cm-1) in the MDS group was significantly higher than in the control group. Patients with AA and MDS exhibited increased serum triglyceride levels and decreased high-density lipoprotein levels.

CONCLUSIONS

The relationship between serological test data for patients and typing of AA and MDS provides essential information for rapid and early identification of BMF. This study shows the potential of Raman spectroscopy for non-invasive detection of different BMF types.

Impact of reduced apolipoprotein A-I levels on pulmonary arterial hypertension

BACKGROUND

The significance of apolipoprotein A-I (ApoA-I) is the anti-inflammatory functional component of high-density lipoprotein, which needs to be further studied in relation to pulmonary arterial hypertension (PAH). This study aimed to identify the predictive value of ApoA-1 on the risk and prognosis of PAH, as well as the underlying anti-inflammatory mechanism.

METHODS

Proteomic analysis was conducted on lung tissue from 6 PAH patients and 4 lung donors. Prediction of risk and mortality risk factors associated with PAH in 343 patients used logistic analysis and Cox regression analysis, respectively. The protective function of ApoA-I was assessed in human pulmonary arterial endothelial cells (HPAEC), while its anti-inflammatory function was evaluated in THP-1 macrophages.

RESULTS

In the lung tissues of patients with PAH, 168 differentially expressed proteins were associated with lipid metabolism according to GO and KEGG enrichment analysis. A protein-protein interaction network identified ApoA-I as a key protein associated with PAH. Lower ApoA-I levels were independent risk factors for PAH and displayed a stronger predictive value for PAH mortality. Plasma interleukin 6 (IL-6) levels were positively correlated with risk stratification and was higher in PAH patients with lower ApoA-I levels. ApoA-I was downregulated in lung tissues of MCT-induced rats. ApoA-I could reduce IL-6-induced pro-proliferative and pro-migratory abilities of HPAEC and inhibit secretion of IL-6 from macrophages, which is compromised under hypoxic conditions.

CONCLUSION

Our study identified the significance of ApoA-I as a biomarker for predicting the survival outcome of PAH patients, which might relate to its altered anti-inflammatory properties.

High-density lipoprotein dysfunction in carotid artery stenosis

Background: High density lipoprotein (HDL) is well established to have an athero-protective role under normal conditions; however, pro-inflammatory alteration of HDL proteins may transform the HDL particle into a dysfunctional molecule. Our aim was to investigate HDL dysfunction by measuring enzyme-based markers in carotid artery stenosis (CAS). Patients and methods: All participants underwent duplex ultrasound and 52 subjects diagnosed with CAS and 51 subjects who had no significant stenosis (as controls) were enrolled in this study. Serum lipid profiles and serum parameters associated with dysfunctional HDL including myeloperoxidase (MPO), paraoxonase 1 (PON1), arylesterase (ARE) activity, and lipid hydroperoxide (LOOH) levels were measured. Results: It was found that the patients with CAS had increased levels of MPO and LOOH while PON1 activity was decreased. There was no significant difference between the CAS and non-CAS groups in terms of HDL levels. MPO/PON1, MPO/ARE, and LOOH/PON1 ratios were significantly increased in the CAS group. MPO/PON1 and MPO/ARE ratios both demonstrated significant correlations with degree of stenosis (%). Conclusions: The MPO/PON1 and MPO/ARE ratios may be potential serum markers that can enable the monitoring of HDL functionality and the assessment of atherosclerotic disease risks. Additionally, monitoring the oxidative balance of lipids on HDL molecules by LOOH/PON1 ratio may have value in the early detection of pro-atherosclerotic transformation of the HDL particle.

A Scoping Review of Nutritional Biomarkers Associated with Food Security

Food insecurity affects more than 40 million individuals in the United States and is linked to negative health outcomes due, in part, to poor dietary quality. Despite the emergence of metabolomics as a modality to objectively characterize nutritional biomarkers, it is unclear whether food security is associated with any biomarkers of dietary quality. This scoping review aims to summarize studies that examined associations between nutritional biomarkers and food security, as well as studies that investigated metabolomic differences between people with and without food insecurity. PubMed, Embase, Scopus, and AGRICOLA were searched through August 2022 for studies describing food insecurity and metabolic markers in blood, urine, plasma, hair, or nails. The 78 studies included consisted of targeted assays quantifying lipids, dietary nutrients, heavy metals, and environmental xenobiotics as biochemical features associated with food insecurity. Among those biomarkers which were quantified in at least five studies, none showed a consistent association with food insecurity. Although three biomarkers of dietary quality have been assessed between food-insecure versus food-secure populations, no studies have utilized untargeted metabolomics to characterize patterns of small molecules that distinguish between these two populations. Further studies are needed to characterize the dietary quality profiles of individuals with and without food insecurity.

Airway and systemic biomarkers of health effects after short-term exposure to indoor ultrafine particles from cooking and candles - A randomized controlled double-blind crossover study among mild asthmatic subjects

BACKGROUND

There is insufficient knowledge about the systemic health effects of exposure to fine (PM_2.5) and ultrafine particles emitted from typical indoor sources, including cooking and candlelight burning. We examined whether short-term exposure to emissions from cooking and burning candles cause inflammatory changes in young individuals with mild asthma. Thirty-six non-smoking asthmatics participated in a randomized controlled double-blind crossover study attending three exposure sessions (mean PM_2.5 µg/m³_; polycyclic aromatic hydrocarbons ng/m³): (a) air mixed with emissions from cooking (96.1; 1.1), (b) air mixed with emissions from candles (89.8; 10), and (c) clean filtered air (5.8; 1.0). Emissions were generated in an adjacent chamber and let into a full-scale exposure chamber where participants were exposed for five hours. Several biomarkers were assessed in relation to airway and systemic inflammatory changes; the primary outcomes of interest were surfactant Protein-A (SP-A) and albumin in droplets in exhaled air - novel biomarkers for changes in the surfactant composition of small airways. Secondary outcomes included cytokines in nasal lavage, cytokines, C-reactive protein (CRP), epithelial progenitor cells (EPCs), genotoxicity, gene expression related to DNA-repair, oxidative stress, and inflammation, as well as metabolites in blood. Samples were collected before exposure start, right after exposure and the next morning.

RESULTS

SP-A in droplets in exhaled air showed stable concentrations following candle exposure, while concentrations decreased following cooking and clean air exposure. Albumin in droplets in exhaled air increased following exposure to cooking and candles compared to clean air exposure, although not significant. Oxidatively damaged DNA and concentrations of some lipids and lipoproteins in the blood increased significantly following exposure to cooking. We found no or weak associations between cooking and candle exposure and systemic inflammation biomarkers including cytokines, CRP, and EPCs.

CONCLUSIONS

Cooking and candle emissions induced effects on some of the examined health-related biomarkers, while no effect was observed in others; Oxidatively damaged DNA and concentrations of lipids and lipoproteins were increased in blood after exposure to cooking, while both cooking and candle emissions slightly affected the small airways including the primary outcomes SP-A and albumin. We found only weak associations between the exposures and systemic inflammatory biomarkers. Together, the results show the existence of mild inflammation following cooking and candle exposure.

Adsorption of Acylhydroperoxy-Derivatives of Phospholipids from Biomembranes by Blood Plasma Lipoproteins

It has been established that acylhydroperoxy derivatives of phospholipids from oxidized rat liver mitochondria are captured predominantly by LDL particles but not by HDL during co-incubation with blood plasma lipoproteins, which refutes the previously suggested hypothesis about the involvement of HDL in the reverse transport of oxidized phospholipids and confirms the possibility of different mechanisms of lipohydroperoxide accumulation in LDL during oxidative stress.

Procoagulant phenotype induced by oxidized high-density lipoprotein associates with acute kidney injury and death

BACKGROUND

Oxidative stress derived from severe systemic inflammation promotes conversion from high-density lipoprotein HDL to oxidized HDL (oxHDL), which interacts with vascular endothelial cells (ECs). OxHDL acquires procoagulant features playing a role in modulating coagulation, which has been linked with organ failure in ICU patients. However, whether oxHDL elicits a ECs-mediated procoagulant phenotype generating organ failure and death, and the underlying molecular mechanism is not known. Therefore, we studied whether oxHDL-treated rats and high-oxHDL ICU patients exhibit a procoagulant phenotype and its association with kidney injury and mortality and the endothelial underlying molecular mechanism.

METHODS

Human ECs, oxHDL-treated rats and ICU patients were subjected to several cellular and molecular studies, coagulation analyses, kidney injury assessment and mortality determination.

RESULTS

OxHDL-treated ECs showed a procoagulant protein expression reprograming characterized by increased E-/P-selectin and vWF mRNA expression through specific signaling pathways. OxHDL-treated rats exhibited a procoagulant phenotype and modified E-/P-selectin, vWF, TF and t-PA mRNA expression correlating with plasma TF, t-PA and D-dimer. Also, showed increased death events and the relative risk of death, and increased creatinine, urea, BUN/creatinine ratio, KIM-1, NGAL, β2M, and decreased eGFR, all concordant with kidney injury, correlated with plasma TF, t-PA and D-dimer. ICU patients showed correlation between plasma oxHDL and increased creatinine, cystatin, BUN, BUN/creatinine ratio, KIM-1, NGAL, β2M, and decreased GFR. Notably, ICU high-oxHDL patients showed decreased survival. Interestingly, altered coagulation factors TF, t-PA and D-dimer correlated with both increased oxHDL levels and kidney injury markers, indicating a connection between these factors.

CONCLUSION

Increased circulating oxHDL generates an endothelial-dependent procoagulant phenotype that associates with acute kidney injury and increased risk of death.

Blood Plasma Lipoproteids: Oxidizability and Participation in the Transport of Acylhydroperoxy-Derivatives of Phospholipids

Oxidatively modified plasma lipoproteins play an important role in the molecular mechanisms of vascular wall damage in atherosclerosis and diabetes mellitus. It was found that the oxidizability of low-density lipoproteins (LDLs) is more than one order of magnitude higher than that of high-density lipoproteins (HDLs). It was shown that acylhydroperoxy derivatives of phospholipids of oxidized biomembranes are predominantly captured by LDL particles, but not by HDLs, which refutes the hypothesis about the involvement of HDLs in the reverse transport of lipohydroperoxides (LOOH). The results suggest the possibility of different mechanisms of LOOH accumulation in LDLs: due to the increased oxidizability of LDLs and due to the effective transmembrane transport of LOOH by LDL particles.

Osteoblast Demineralization Induced by Oxidized High-Density Lipoprotein via the Inflammatory Pathway Is Suppressed by Adiponectin

Low mineralization activity by human osteoblast cells (HOBs) indicates abnormal bone remodeling that potentially leads to osteoporosis. Oxidation, the most prominent form of high-density lipoprotein (HDL) modification, is suggested to affect bone mineralization through the inflammatory pathway. Adiponectin, which possesses anti-inflammatory activity, is postulated to have the ability to suppress the detrimental effects of oxidized HDL (oxHDL). This study aimed to investigate the effects of HDL before and after oxidation on markers of mineralization and inflammation. The protective effects of adiponectin on demineralization and inflammation induced by oxHDL were also investigated. OxHDL at 100 µg/mL protein had the highest inhibitory effect on mineralization, followed by lower calcium incorporation. OxHDL also had significantly lower expression of a mineralization marker (COL1A2) and higher expression of inflammatory markers (IL-6, TNF-α, and RELA proto-oncogene, NF-κβ (p65)) compared to the unstimulated control group. These findings suggest that oxHDL reduces the mineralization activity of HOBs by increasing the expression of inflammatory markers. Interestingly, co-incubation of adiponectin and oxHDL in HOBs resulted in higher expression of mineralization markers (ALPL, COL1A2, BGLAP, and RUNX2) and significantly reduced all targeted inflammatory markers compared to the oxHDL groups. On the contrary, HDL increased the expression of mineralization markers (COL1A2 and STAT-3) and exhibited lower expression of inflammatory cytokines (IL-6 and TNF-α), proving the protective effect of HDL beyond the reverse cholesterol transport activity.

Increased Lipid Peroxidation and Lowered Antioxidant Defenses Predict Methamphetamine Induced Psychosis

BACKGROUND

a significant percentage of methamphetamine (MA) dependent patients develop psychosis. The associations between oxidative pathways and MA-induced psychosis (MIP) are not well delineated.

OBJECTIVE

the aim of this study is to delineate whether acute MA intoxication in MA dependent patients is accompanied by increased nitro-oxidative stress and whether the latter is associated with MIP.

METHOD

we recruited 30 healthy younger males and 60 acutely intoxicated males with MA dependence and assessed severity of MA use and dependence and psychotic symptoms during intoxication, and serum oxidative toxicity (OSTOX) biomarkers including oxidized high (oxHDL) and low (oxLDL)-density lipoprotein, myeloperoxidase (MPO), malondialdehyde (MDA), and nitric oxide (NO), and antioxidant defenses (ANTIOX) including HDL-cholesterol, zinc, glutathione peroxidase (GPx), total antioxidant capacity (TAC), and catalase-1.

RESULTS

a large part (50%, n = 30) of patients with MA dependence could be allocated to a cluster characterized by high psychosis ratings including delusions, suspiciousness, conceptual disorganization and difficulties abstract thinking and an increased OSTOX/ANTIOX ratio. Partial Least Squares analysis showed that 29.9% of the variance in MIP severity (a first factor extracted from psychosis, hostility, excitation, mannerism, and formal thought disorder scores) was explained by HDL, TAC and zinc (all inversely) and oxLDL (positively). MA dependence and dosing explained together 44.7% of the variance in the OSTOX/ANTIOX ratio.

CONCLUSIONS

MA dependence and intoxication are associated with increased oxidative stress and lowered antioxidant defenses, both of which increase risk of MIP during acute intoxication. MA dependence is accompanied by increased atherogenicity due to lowered HDL and increased oxLDL and oxHDL.

Early Midlife Cardiovascular Health Influences Future HDL Metrics in Women: The SWAN HDL Study

Background Utility of high-density lipoprotein cholesterol (HDL-C) in assessing the antiatherogenic properties of HDL may be limited in midlife women. Novel metrics of HDL function, lipid contents, and subclasses may better reflect the atheroprotective capacities of HDL, supporting the need to evaluate how cardiovascular health affects these metrics in women. We assessed the relationship of early midlife Life's Simple 7 (LS7) score and its health behavior components with future HDL function (HDL-cholesterol efflux capacity), HDL-phospholipid, HDL-triglyceride, HDL particles (HDL-P) and size, and the relationship between LS7 score and changes in HDL metrics over time. Methods and Results We analyzed 529 women (baseline age: 46.4 [2.6] years, 57% White) from the SWAN HDL (Study of Women's Health Across the Nation HDL) study who had baseline LS7 followed by future repeated HDL metrics. Multivariable linear mixed models were used. Higher LS7 score was associated with favorable future HDL profile (higher HDL-phospholipid, total HDL-P and large HDL-P, lower HDL-triglyceride, and larger overall HDL size). Ideal body mass index was associated with higher HDL-cholesterol efflux capacity, HDL-phospholipid, and large HDL-P, lower HDL-triglyceride and small HDL-P, and larger overall HDL size. Ideal physical activity was associated with higher HDL-phospholipid, and total, large, and medium HDL-P. Ideal smoking was associated with less HDL-triglycerides. Diet was not related to HDL metrics. Higher LS7 score and ideal body mass index were associated with slower progression of HDL size over time. Conclusions Novel HDL metrics may better reflect the clinical utility of HDL. Improving lifestyle at midlife, particularly maintaining ideal body mass index, is associated with better future HDL phenotype.

High-density lipoprotein cholesterol to apolipoprotein A-1 ratio is an important indicator predicting in-hospital death in patients with acute coronary syndrome

BACKGROUND

Dyslipidemia plays a pivotal role in the pathogenesis of acute coronary syndrome (ACS). This study aims to investigate the value of two indices associated with lipid metabolism, low-density lipoprotein cholesterol to apolipoprotein B ratio (LBR) and high-density lipoprotein cholesterol to apolipoprotein A-1 ratio (HAR), to predict in-hospital death in patients with ACS.

METHODS

This single-center, retrospective, observational study included 3,366 consecutive ACS patients in Zhongda Hospital, Southeast University from July 2013 to January 2018. The clinical and laboratory data were extracted, and the in-hospital death and hospitalization days were also recorded.

RESULTS

All patients were equally divided into four groups according to quartiles of HAR: Q1 (HAR < 1.0283), Q2 (1.0283 ≤ HAR < 1.0860), Q3 (1.0860 ≤ HAR < 1.1798), and Q4 (HAR ≥ 1.1798). Overall, HAR was positively associated with the counts of neutrophils and monocytes, whereas negatively correlated to lymphocyte counts. HAR was negatively correlated to left ventricular ejection fraction (LVEF). Compared to other three groups, in-hospital mortality (vs. Q1, Q2, and Q3, p < 0.001) and hospitalization length (vs. Q1, Q2, and Q3, p < 0.001) were significantly higher in the Q4 group. When grouped by LBR, however, there was no significant difference in LVEF, in-hospital mortality, and hospitalization length among groups. After adjusting potential impact from age, systolic blood pressure, creatine, lactate dehydrogenase, albumin, glucose, and uric acid, multivariate analysis indicated that HAR was an independent factor predicting in-hospital death among ACS patients.

CONCLUSIONS

HAR had good predictive value for patients' in-hospital death after the occurrence of acute coronary events, but LBR was not related to in-hospital adverse events.

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.

Oxidized high-density lipoprotein promotes CD36 palmitoylation and increases lipid uptake in macrophages

Oxidized high-density lipoprotein (oxHDL) reduces the ability of cells to mediate reverse cholesterol transport and also shows atherogenic properties. Palmitoylation of cluster of differentiation 36 (CD36), an important receptor mediating lipoprotein uptake, is required for fatty acid endocytosis. However, the relationship between oxHDL and CD36 has not been described in mechanistic detail. Here, we demonstrate using acyl-biotin exchange analysis that oxHDL activates CD36 by increasing CD36 palmitoylation, which promotes efficient uptake in macrophages. This modification increased CD36 incorporation into plasma lipid rafts and activated downstream signaling mediators, such as Lyn, Fyn, and c-Jun N-terminal kinase, which elicited enhanced oxHDL uptake and foam cell formation. Furthermore, blocking CD36 palmitoylation with the pharmacological inhibitor 2-bromopalmitate decreased cell surface translocation and lowered oxHDL uptake in oxHDL-treated macrophages. We verified these results by transfecting oxHDL-induced macrophages with vectors expressing wildtype or mutant CD36 (mCD36) in which the cytoplasmic palmitoylated cysteine residues were replaced. We show that cells containing mCD36 exhibited less palmitoylated CD36, disrupted plasma membrane trafficking, and reduced protein stability. Moreover, in ApoE^−/−CD36^−/− mice, lipid accumulation at the aortic root in mice receiving the mCD36 vector was decreased, suggesting that CD36 palmitoylation is responsible for lipid uptake in vivo. Finally, our data indicated that palmitoylation of CD36 was dependent on DHHC6 (Asp-His-His-Cys) acyltransferase and its cofactor selenoprotein K, which increased the CD36/caveolin-1 interaction and membrane targeting in cells exposed to oxHDL. Altogether, our study uncovers a causal link between oxHDL and CD36 palmitoylation and provides insight into foam cell formation and atherogenesis.

Association of anti-oxidative capacity of HDL with subclinical atherosclerosis in subjects with and without non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) patients are at a substantial risk for developing cardiovascular disease (CVD). High-density lipoprotein (HDL) is well known to have protective effects against the development of atherosclerotic CVD. One of the major antiatherogenic effects of HDL is its anti-oxidative function.

OBJECTIVES

This study investigated the association of anti-oxidative capacity of HDL with subclinical atherosclerosis in NAFLD and non-NAFLD subjects.

METHODS

A total of 143 subjects including 51 NAFLD and 92 control subjects were included in this case-control study. HDL oxidative index (HOI) was determined spectrophotometrically using a cell-free method in the presence of a fluorescent substrate dichlorofluorescein diacetate (DCFDA). Paraoxonase 1 (PON1) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) plasma levels were assessed in both groups.

RESULTS

The NAFLD patients with impaired HDL anti-oxidative function (HOI  ≥ 1) had higher MDA levels, aspartate amino transferase (AST), liver stiffness (LS), and carotid intima-media thickness (cIMT) values compared to the controls. HDL oxidative index (HOI) was positively correlated with MDA levels and cIMT and negatively correlated with SOD activity.

CONCLUSIONS

Higher circulating levels of MDA were associated with the impaired anti-oxidative function of HDL in NAFLD. The impaired anti-oxidative capacity of HDL might be related to NAFLD severity and subclinical atherosclerosis in NAFLD patients.

Malondialdehyde-modified HDL particles elicit a specific IgG response in abdominal aortic aneurysm

High Density Lipoprotein (HDL) plays a protective role in abdominal aortic aneurysm (AAA); however, recent findings suggest that oxidative modifications could lead to dysfunctional HDL in AAA. This study aimed at testing the effect of oxidized HDL on aortic lesions and humoral immune responses in a mouse model of AAA induced by elastase, and evaluating whether antibodies against modified HDL can be found in AAA patients. HDL particles were oxidized with malondialdehyde (HDL-MDA) and the changes were studied by biochemical and proteomics approaches. Experimental AAA was induced in mice by elastase perfusion and then mice were treated with HDL-MDA, HDL or vehicle for 14 days. Aortic lesions were studied by histomorphometric analysis. Levels of anti-HDL-MDA IgG antibodies were measured by an in-house immunoassay in the mouse model, in human tissue-supernatants and in plasma samples from the VIVA cohort. HDL oxidation with MDA was confirmed by enhanced susceptibility to diene formation. Proteomics demonstrated the presence of MDA adducts on Lysine residues of HDL proteins, mainly ApoA-I. MDA-modification of HDL abrogated the protective effect of HDL on cultured endothelial cells as well as on AAA dilation in mice. Exposure to HDL-MDA elicited an anti-HDL-MDA IgG response in mice. Anti-HDL-MDA were also detected in tissue-conditioned media from AAA patients, mainly in intraluminal thrombus. Higher plasma levels of anti-HDL-MDA IgG antibodies were found in AAA patients compared to controls. Anti-HDL-MDA levels were associated with smoking and were independent predictors of overall mortality in AAA patients. Overall, MDA-oxidized HDL trigger a specific humoral immune response in mice. Besides, antibodies against HDL-MDA can be detected in tissue and plasma of AAA patients, suggesting its potential use as surrogate stable biomarkers of oxidative stress in AAA.

HDL Dysfunctionality: Clinical Relevance of Quality Rather Than Quantity

High-density lipoproteins (HDLs) represent a class of lipoproteins very heterogeneous in structure, composition, and biological functions, which carry out reverse cholesterol transport, antioxidant, anti-inflammatory, antithrombotic, and vasodilator actions. Despite the evidence suggesting a clear inverse relationship between HDL cholesterol (HDL-c) concentration and the risk for cardiovascular disease, plasma HDL cholesterol levels do not predict the functionality and composition of HDLs. The importance of defining both the amount of cholesterol transported and lipoprotein functionality has recently been highlighted. Indeed, different clinical conditions such as obesity, diabetes mellitus type 2 (T2DM), and cardiovascular disease (CVD) can alter the HDL functionality, converting normal HDLs into dysfunctional ones, undergoing structural changes, and exhibiting proinflammatory, pro-oxidant, prothrombotic, and proapoptotic properties. The aim of the current review is to summarize the actual knowledge concerning the physical-chemical alteration of HDLs related to their functions, which have been found to be relevant in several pathological conditions associated with systemic inflammation and oxidative stress.

Physiological Network From Anthropometric and Blood Test Biomarkers

Currently, research in physiology focuses on molecular mechanisms underlying the functioning of living organisms. Reductionist strategies are used to decompose systems into their components and to measure changes of physiological variables between experimental conditions. However, how these isolated physiological variables translate into the emergence -and collapse- of biological functions of the organism as a whole is often a less tractable question. To generate a useful representation of physiology as a system, known and unknown interactions between heterogeneous physiological components must be taken into account. In this work we use a Complex Inference Networks approach to build physiological networks from biomarkers. We employ two unrelated databases to generate Spearman correlation matrices of 81 and 54 physiological variables, respectively, including endocrine, mechanic, biochemical, anthropometric, physiological, and cellular variables. From these correlation matrices we generated physiological networks by selecting a p-value threshold indicating statistically significant links. We compared the networks from both samples to show which features are robust and representative for physiology in health. We found that although network topology is sensitive to the p-value threshold, an optimal value may be defined by combining criteria of stability of topological features and network connectedness. Unsupervised community detection algorithms allowed to obtain functional clusters that correlate well with current medical knowledge. Finally, we describe the topology of the physiological networks, which lie between random and ordered structural features, and may reflect system robustness and adaptability. Modularity of physiological networks allows to explore functional clusters that are consistent even when considering different physiological variables. Altogether Complex Inference Networks from biomarkers provide an efficient implementation of a systems biology approach that is visually understandable and robust. We hypothesize that physiological networks allow to translate concepts such as homeostasis into quantifiable properties of biological systems useful for determination and quantification of health and disease.

Relationship Between Metabolic Syndrome and Cognitive Function: A Population-Based Study of Middle-Aged and Elderly Adults in Rural China

INTRODUCTION

To explore the relationship between metabolic syndrome (MetS) and cognitive impairment in a low-income and low-education population.

METHODS

All residents aged ≥45 years in a low-income population in Tianjin, China, were eligible to participate in this study. The Mini-Mental State Examination (MMSE) scale was used to conduct a preliminary screening and assessment of the participants' cognitive statuses. The MMSE components are orientation, registration, attention and calculation, recall, and language.

RESULTS

In this population, the prevalences of MetS and cognitive impairment were 54.1% and 44.5%, respectively. In the overall population, the registration score was 0.105 points lower in the elevated triglycerides (TG) group than in the normal TG group (β, -0.105; 95% confidence interval [CI]: -0.201, -0.010; P=0.030). In men, high TG was associated with registration scores that were 0.152 points lower than those in the normal TG group (95% CI: -0.281, -0.022; P=0.022), while larger WC and lower HDL-C had positive effects on cognitive scores (all P<0.05). However, in women, there were no significant differences between cognitive scores and MetS or its components.

CONCLUSION

In this population, first, TG had a great impact on cognition, even greater than the impact of MetS on cognition. Second, the impact of MetS components on cognition was more obvious in men, and not all of the effects were negative. Therefore, the effect of MetS on cognition may need to be analyzed separately for different populations, and it may be that the effect of a single component is greater than the overall effect. When formulating prevention strategies for cognitive impairments, population differences must also be taken into consideration.

An RCT of acute health effects in COPD-patients after passive vape exposure from e-cigarettes

Background: E-cigarette use has been shown to have short-term acute effects among active users but less is known of the acute passive effects, particularly among individuals with existing respiratory diseases. Objective: To investigate local and systemic effects of short-term passive vape exposure among patients with mild or moderate chronic obstructive pulmonary disease (COPD). Methods: In a double-blinded crossover study 16 non-smoking COPD-patients (mean age 68) were randomly exposed for 4 h to passive vape (median PM2.5: 18 µg/m3 (range: 8-333)) and clean air (PM2.5 < 6 µg/m3) separated by 14 days. Particles were measured using an ultrafine particle counter (P-TRAK) and a scanning mobility particle sizer (SMPS). Health effects including Surfactant Protein-A (SP-A) and albumin in exhaled air, spirometry, FeNO, and plasma proteins were evaluated before, right after, and 24 hours after exposure. Participants reported symptoms throughout exposure sessions. Data were analyzed using mixed models. Results: SP-A in exhaled air was negatively affected by exposure to vape and several plasma proteins increased significantly. Throat irritation was more pronounced during passive vape exposure, while FVC and FEV1 decreased, however, not significantly. Conclusions: SP-A in exhaled air and some plasma proteins were affected by passive vape in patients with COPD indicating inflammation, showing that passive vape exposure is potentially harmful.

From Inert Storage to Biological Activity-In Search of Identity for Oxidized Cholesteryl Esters

Esterification of cholesterol is a universal mechanism to store and transport large quantities of cholesterol between organs and tissues and to avoid toxicity of the excess of cellular cholesterol. Intended for transport and storage and thus to be inert, cholesteryl esters (CEs) reside in hydrophobic cores of circulating lipoproteins and intracellular lipid droplets. However, the inert identity of CEs is dramatically changed if cholesterol is esterified to a polyunsaturated fatty acid and subjected to oxidative modification. Post-synthetic, or epilipidomic, oxidative modifications of CEs are mediated by specialized enzymes, chief among them are lipoxygenases, and by free radical oxidation. The complex repertoire of oxidized CE (OxCE) products exhibit various, context-dependent biological activities, surveyed in this review. Oxidized fatty acyl chains in OxCE can be hydrolyzed and re-esterified, thus seeding oxidized moieties into phospholipids (PLs), with OxPLs having different from OxCEs biological activities. Technological advances in mass spectrometry and the development of new anti-OxCE antibodies make it possible to validate the presence and quantify the levels of OxCEs in human atherosclerotic lesions and plasma. The article discusses the prospects of measuring OxCE levels in plasma as a novel biomarker assay to evaluate risk of developing cardiovascular disease and efficacy of treatment.