Oxidized phospholipids and lipoprotein-associated phospholipase A2 (Lp-PLA2 ) in atherosclerotic cardiovascular disease: An update

A colorectal liver metastasis prediction model based on the combination of lipoprotein-associated phospholipase A2 and serum biomarker levels

OBJECTIVE

This study aims to assess the predictive value of serum lipoprotein-associated phospholipase A2 (Lp-PLA2) in colorectal liver metastasis (CRLM) patients.

METHODS

A total of 507 participants were recruited for this study, comprising 162 healthy controls (HCs), 186 non-CRLM patients, and 159 CRLM patients. Serum Lp-PLA2 levels were measured across these three groups, and a CRLM prediction model was developed using machine learning (ML) algorithms in conjunction with traditional serological markers. The performance of each model was assessed using the area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, and other relevant metrics.

RESULTS

The serum Lp-PLA2 levels in CRLM patients were significantly elevated compared to those in HCs group and the non-CRLM group (P < 0.0001). The CRLM prediction model developed using the Random forest algorithm demonstrated superior performance, incorporating six features: Lp-PLA2, ALB, GLB, ALT, LDH, and TC. This model achieved an AUC of 0.918, with a sensitivity of 0.823, specificity of 0.889, positive predictive value (PPV) of 0.861, and negative predictive value (NPV) of 0.857.

CONCLUSION

The Random forest model, incorporating serum Lp-PLA2 level and conventional laboratory parameters, demonstrates robust predictive capability for CRLM and holds promise for enhancing early detection in CRLM patients.

Winery By-Products In Vitro and In Vivo Effects on Atherothrombotic Markers: Focus on Platelet-Activating Factor

Platelet aggregation and inflammation play a crucial role in atherothrombosis. Wine contains micro-constituents of proper quality and quantity that exert cardioprotective actions, partly through inhibiting platelet-activating factor (PAF), a potent inflammatory and thrombotic lipid mediator. However, wine cannot be consumed extensively due to the presence of ethanol. Alternatively, winery by-products are abundant in similar-to-wine micro-constituents that could be used in food fortification and dietary supplements. Also, the vinification process produces millions of tons of by-products worldwide, posing an environmental matter of waste management. Therefore, the purpose of this literature review is to update the existing data concerning the in vitro anti-platelet and anti-inflammatory properties of winery by-product extracts and their possible health effects through controlled clinical trials in humans, specifically focused on their effects on PAF's actions. Data from in vitro studies report that winery by-product compounds are able to inhibit platelet aggregation against several aggregation factors, as well as to downregulate inflammatory markers. Among their actions, extracts or phenolic compounds present in winery by-products inhibit PAF's actions, a potent inflammatory and thrombotic mediator. Similar conclusions have been drawn from human supplementation studies, which suggest that winery by-product extracts may have beneficial biological effects on the cardiovascular system. Evidence from long-term studies shows that consumption may lower total and low density lipoprotein (LDL) cholesterol, improve insulin sensitivity, decrease lipid and protein oxidative damage, enhance antioxidant capacity, and have mild anti-inflammatory action toward reducing cytokine expression and levels. Data from the limited postprandial studies report that the acute consumption of winery by-product extracts improves glycemic response and reduces platelet reactivity to aggregatory stimuli. Although wine extracts and phenolic compounds have been reported to inhibit PAF's actions and reduce the activity of its biosynthetic enzymes, no data exist concerning the influence of winery by-product extracts. In the future, additional long-term randomized controlled trials or postprandial studies are needed to draw definitive conclusions and establish a viable cardioprotective strategy that incorporates the sustainable use of winery by-products.

Phospholipid-derived lysophospholipids in (patho)physiology

Phospholipids (PL) are major components of cellular membranes and changes in PL metabolism have been associated with the pathogenesis of numerous diseases. Lysophosphatidylcholine (LPC) in particular, is a comparably abundant component of oxidatively damaged tissues. LPC originates from the cleavage of phosphatidylcholine (PC) by phospholipase A2 or the reaction of lipids with reactive oxygen species (ROS) such as HOCl. Another explanation of increased LPC concentration is the decreased re-acylation of LPC into PC. While there are also several other lysophospholipids, LPC is the most abundant lysophospholipid in mammals and will therefore be the focus of this review. LPC is involved in many physiological processes. It induces the migration of lymphocytes, fostering the production of pro-inflammatory compounds by inducing oxidative stress. LPC also "signals" via G protein-coupled and Toll-like receptors and has been implicated in the development of different diseases. However, LPCs are not purely "bad": this is reflected by the fact that the concentration and fatty acyl composition of LPC varies under different conditions, in plasma of healthy and diseased individuals, in tissues and different tumors. Targeting LPC and lipid metabolism and restoring homeostasis might be a potential therapeutic method for inflammation-related diseases.

Longitudinal lipidomic profiles of left ventricular mass and left ventricular hypertrophy in American Indians

BACKGROUNDLeft ventricular hypertrophy (LVH) and dyslipidemia are strong, independent predictors for cardiovascular disease, but their relationship is less well studied. A longitudinal lipidomic profiling of left ventricular mass (LVM) and LVH is still lacking.METHODSUsing liquid chromatography-mass spectrometry (LC-MS), we repeatedly measured 1,542 lipids from 1,755 unique American Indians attending 2 exams (mean, 5 years apart). Cross-sectional associations of individual lipid species with LVM index (LVMI) were examined by generalized estimating equation (GEE), followed by replication in an independent biracial cohort (65% White, 35% Black). Baseline plasma lipids associated with LVH risk beyond traditional risk factors were identified by logistic GEE model in American Indians. Longitudinal associations between changes in lipids and changes in LVMI were examined by GEE, adjusting for baseline lipids, baseline LVMI, and covariates.RESULTSMultiple lipid species were significantly associated with LVMI or the risk of LVH in American Indians. Some lipids were confirmed in Black and White individuals. Moreover, some LVH-related lipids were inversely associated with risk of coronary heart disease (CHD). Longitudinal changes in several lipid species were significantly associated with changes in LVMI.CONCLUSIONAltered fasting plasma lipidome and its longitudinal change over time were significantly associated with LVMI and risk for LVH in American Indians. Our results offer insight into the role of individual lipid species in LV remodeling and risk of LVH, independent of known risk factors.FUNDINGThis study was supported by the NIH grant (R01DK107532). The Strong Heart Study has been funded in whole or in part with federal funds from the National Heart, Lung, and Blood Institute, NIH, Department of Health and Human Services, under contract nos. 75N92019D00027, 75N92019D00028, 75N92019D00029, and 75N92019D00030.

Association between lipoprotein-associated phospholipase A2 and 25-hydroxy-vitamin D on early stage diabetic kidney disease in patients with type-2 diabetes mellitus

Objective

This study aimed to analyse the association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and 25-hydroxy-vitamin D (25[OH]D) and early diabetic kidney disease (DKD) in patients with type 2 diabetes mellitus (T2DM) and evaluate the potential roles of these two biomarkers in the clinical diagnosis of DKD.

Methods

A total of 422 inpatients with T2DM were retrospectively enrolled between January 2018 and March 2022 at the First Affiliated Hospital of Nanjing Medical University. The baseline clinical parameters of each patient were determined, and their demographic characteristics were extracted from the hospital information system. The patients were separated into groups according to serum Lp-PLA2 and 25(OH)D levels and binary logistic regression analysis was used to determine independent predictors of early DKD incidence.

Results

Levels of Lp-PLA2 significantly increased and those of 25(OH)D significantly decreased with DKD progression (both P < 0.001). Lp-PLA2 concentrations were positively correlated with albuminuria levels (r = 0.37, P < 0.001), whereas 25(OH)D levels were negatively correlation (r = -0.34, P < 0.001). The incidence of DKD was higher in the Lp-PLA2 elevated and 25(OH)D deficient groups (all P < 0.001). Body mass index, systemic immune-inflammatory index, serum uric acid, C-peptide, and triglyceride-glucose indices were positively associated with Lp-PLA2 levels (all P < 0.001) and negatively associated with 25(OH)D (all P < 0.05). Furthermore, Lp-PLA2 was an independent risk factor (OR = 1.003, P = 0.015), and 25(OH)D was an independent protective factor (OR = 0.937, P = 0.008) for early DKD occurrence in binary logistic regression analysis. The area under the curve for the combination of Lp-PLA2 and 25(OH)D for diagnosing DKD was 0.867, with a sensitivity of 70.4 % and a specificity of 89.5 %.

Conclusions

Increased serum Lp-PLA2 and decreased 25(OH)D levels are risk factors for early DKD in patients with T2DM. The combined detection of Lp-PLA2 and 25(OH)D may enhance the diagnostic efficacy of DKD.

Predictive and therapeutic value of lipoprotein-associated phospholipaseA2 in sarcopenia in chronic obstructive pulmonary disease

BACKGROUND

Sarcopenia, characterized by progressive muscle dysfunction, is a common complication of chronic obstructive pulmonary disease (COPD). Our previous study revealed serum Lipoprotein-associated phospholipaseA2 (Lp-PLA2) level significantly increased in COPD and associated with exercise tolerance. This study further investigated the functions and target potential of Lp-PLA2 for sarcopenia in COPD.

METHODS

The circulating Lp-PLA2 level/enzyme activity in COPD patients and age-matched healthy volunteers were measured. Clinical parameters on skeletal muscle were measured and their correlations with Lp-PLA2 were analyzed. We explored the involvement of Lp-PLA2 in vivo and treatment effectiveness of darapladib (a specific Lp-PLA2 inhibitor) in CS-induced muscle dysfunction models.

RESULTS

Circulating Lp-PLA2 level/enzyme activity was elevated in COPD patients compared with healthy controls, negatively associated with skeletal muscle mass and function. In CS-induced muscle dysfunction murine models, up-regulated serum Lp-PLA2 level/enzyme activity was verified again. In CS-exposed mouse models, darapladib treatment reversed muscle mass loss and muscle dysfunction, meanwhile rescued upregulation of MuRF1 and atrogin-1, and activation of inflammatory factors, oxidant enzymes and NF-κB signaling.

CONCLUSIONS

Lp-PLA2 could be a potential indicator for sarcopenia in COPD. Darapladib, a Lp-PLA2 inhibitor, can alleviate CS-induced skeletal muscle dysfunction and represents a potential therapeutic for sarcopenia in COPD.

Revisiting the role of phospholipases in alzheimer's: crosstalk with processed food

Phospholipases such as phospholipase-A, phospholipase-B, phospholipase-C and phospholipase-D are important functional enzymes of the cell membrane responsible for a variety of functions such as signal transduction, production of lipid mediators, metabolite digestion and playing a pathological role in central nervous system diseases. Phospholipases have shown an association with Alzheimer's disease and these enzymes have found a correlation with several metabolic pathways that can lead to the activation of inflammatory signals via astrocytes and microglial cells. We also highlighted unhealthy practices like smoking and consuming processed foods, rich in nitroso compounds and phosphatidic acid, which contribute to neuronal damage in AD through phospholipases. A few therapeutic approaches such as the use of inhibitors of phospholipase-D,phospholipase A2 as well as autophagy-mediated inhibition have been discussed to control the onset of AD. This paper serves as a crosstalk between phospholipases and their role in neurodegenerative pathways as well as their influence on other biomolecules of lipid membranes, which are acquired through unhealthy diets and possible methods to treat these anomalies occurring due to their metabolic disorder involving phospholipases acting as major signaling molecules.

Lipoprotein(a)'s Role in Atherosclerosis and Aortic Stenosis: A Contemporary Literature Review

Lipoprotein(a), or Lp(a), is a distinctive lipoprotein particle linked to various cardiovascular diseases, notably atherosclerosis and aortic stenosis. Much like plasminogen, Lp(a) hinders normal fibrinolysis, leading to increased thrombosis and slower clearance of fibrin debris. It also causes inflammation, oxidative stress, and endothelial dysfunction, contributing to the formation of atherosclerotic lesions. Epidemiological studies have consistently shown that even slight increases in Lp(a) levels correlate with a heightened risk of cardiovascular events. Furthermore, Lp(a) plays a role in aortic stenosis by binding to leaflet valves, accumulating within them, and triggering calcium deposition and nodule formation. These calcium deposits gradually narrow the arteries, impeding blood flow. By raising inflammation and oxidative stress in the valve, Lp(a) accelerates tissue damage and calcium deposition. Traditional lipid-lowering therapies have limited efficacy in reducing Lp(a) levels. However, new treatments using RNA interference and antisense oligonucleotides to decrease Lp(a) production in the liver offer promising prospects for mitigating the risks and managing atherosclerosis and aortic stenosis associated with high Lp(a) levels. As Lp(a) screening becomes more common in healthcare, physicians will be better equipped to assess patients' risk levels and provide tailored treatments. This review aims to examine the role of Lp(a) in the development of aortic stenosis and atherosclerosis.

Research Advance of Chinese Medicine in Treating Atherosclerosis: Focus on Lipoprotein-Associated Phospholipase A2

As a serious cardiovascular disease, atherosclerosis (AS) causes chronic inflammation and oxidative stress in the body and poses a threat to human health. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a member of the phospholipase A2 (PLA2) family, and its elevated levels have been shown to contribute to AS. Lp-PLA2 is closely related to a variety of lipoproteins, and its role in promoting inflammatory responses and oxidative stress in AS is mainly achieved by hydrolyzing oxidized phosphatidylcholine (oxPC) to produce lysophosphatidylcholine (lysoPC). Moreover, macrophage apoptosis within plaque is promoted by localized Lp-PLA2 which also promotes plaque instability. This paper reviews those researches of Chinese medicine in treating AS via reducing Lp-PLA2 levels to guide future experimental studies and clinical applications related to AS.

A cross-sectional study exploring the relationship between oxidative balance score and 10-year atherosclerotic cardiovascular disease risk based on the National Health and Nutrition Examination Survey (2011-2020)

BACKGROUND

The intricate interaction between oxidative stress and atherosclerotic cardiovascular disease (ASCVD) is an essential area of research because of the potential role of oxidative homeostasis in regulating ASCVD risk. This study aimed to investigate the relationship between the oxidative balance score (OBS) and the 10-years risk of ASCVD to gain insight into how oxidative balance affects cardiovascular health.

METHODS

This cross-sectional study analyzed National Health and Nutrition Examination Survey (NHANES) 2011-2020 data (40-79 age group), exploring OBS's link to 10-years ASCVD risk. OBS categorized dietary and lifestyle factors. Multivariate logistic regression controlled for age, sex, race, and demographics. A restricted cubic spline examined linear relationships; robustness was ensured through subgroup analyses.

RESULTS

Analysis of 4955 participants reveals a negative association between OBS and 10-years ASCVD risk. Continuous OBS adjusted OR: 0.97 (95% CI: 0.95∼0.99, p < .001). Quartile analysis shows reduced risk in Q2 0.88 (95% CI: 0.63∼1.22, p = .43), Q3 0.92 (95% CI: 0.66∼1.28, p = .614), and Q4 0.59 (95% CI: 0.42∼0.83, p = .002) compare Q1. Quartile analysis indicated decreasing risk in higher OBS quartiles. Lifestyle OBS and Dietary OBS demonstrated similar trends. Stratified analyses highlight race and hypertension as effect modifiers (p < .05).

CONCLUSION

Our study suggests an association between higher OBS and a reduced 10-years ASCVD risk. However, causation should not be inferred, and in the future, more extensive clinical and fundamental research is required to delve deeper into this association.

The predictive value of miR-377 and phospholipase A2 in the early diagnosis of diabetic kidney disease and their relationship with inflammatory factors

OBJECTIVE

The value of novel biomarkers for DKD has received increasing attention, and there is an urgent need for novel biomarkers with sensitivity, specificity and ability to detect kidney damage.miR-377 regulates many basic biological processes, plays a key role in tumor cell proliferation, migration and inflammation, and can also increase the expression of matrix proteins and fibronectin, leading to renal tubulointerstitial inflammation and renal fibrosis. Lipoprotein-associated phospholipase A2, as an inflammatory marker, is involved in the pathological process of microalbuminuria production and renal function decline, and is a predictive factor of microalbuminuria production and renal function decline, and can be used as an indicator to evaluate the progression of DKD.The aim of this study was to investigate the effects of miR-377 and phospholipase A2 on the development of diabetic kidney disease through regulation of inflammatory factors and the mechanism of action.

METHODS

80 diabetic patients were divided into two groups according to urinary albumin-to-creatinine ratio (UACR): diabetic normal proteinuria group (n = 42) and diabetic proteinuria group (n = 38). Forty-three healthy people were selected as the normal control group. The serum levels of TGF-β, IL-6, and IL-18 were measured by ELISA, miR-377 was detected by qPCR, and the serum levels of phospholipase A2 were detected by electrochemiluminescence. Analyze the correlation of study group indicators, ROC curve was used to evaluate the diagnostic efficacy of miR-377 and phospholipase A2 in diabetic kidney disease.

RESULTS

The average levels of serum TGF-β, IL-6, IL-18, miR-377 and phospholipase A2 in diabetic proteinuria group were significantly higher than those in normal control group and diabetic proteinuria normal group(P < 0.05). miR-377, phospholipase A2 were significantly correlated with inflammatory factors such as glomerular filtration rate and TGF-β. miR-377 and phospholipase A2 are independent predictors of diabetic kidney disease. The area under the curve of miR-377 and phospholipase A2 in the normal diabetic proteinuria group and the diabetic proteinuria group were 0.731 and 0.744, respectively.

CONCLUSION

miR-377 and phospholipase A2 have good diagnostic efficiency for the early diagnosis of diabetic kidney disease. They can be used as early biomarkers.miR-377 and phospholipase A2 were positively correlated with inflammatory factors and involved in the occurrence and development of diabetic kidney disease.

The 10 essential questions regarding lipoprotein(a)

PURPOSE OF REVIEW

Lp(a) is one of the most atherogenic lipoproteins, and significant progress has been made to understand its pathophysiology over the last 20 years. There are now selective therapies in late-stage clinical trials to lower Lp(a). Yet there are many outstanding questions about Lp(a). This review outlines 10 of the most burning questions and tries to answer some of them.

RECENT FINDINGS

Antisense oligonucleotide (ASO) treatment is currently the most advanced therapy to lower plasma Lp(a) by 60-80%. There are, however, also two small molecule medications in early stage of development with similar efficacy.

SUMMARY

This review aims to answer important preclinical and clinical questions about the metabolism and physiological role of Lp(a) and also outlines possible therapeutic approaches with nutraceuticals, currently available lipid-lowering therapies and new medications. In addition, ways are illustrated to use Lp(a) as a marker to better predict cardiovascular risk.

Treatment of Lp(a): Is It the Future or Are We Ready Today?

PURPOSE OF REVIEW

The goal of this review is to present the pharmacodynamic effectiveness as well as the clinical efficacy and safety of investigational antisense oligonucleotides (ASOs) and small interference RNAs (siRNAs) drugs that specifically target lipoprotein(a) (Lp(a)). The review will discuss whether the existing lipid-lowering therapies are adequate to treat high Lp(a) levels or whether it is necessary to use the emerging new therapeutic approaches which are based on the current RNA technologies.

RECENT FINDINGS

Lipoprotein(a) (Lp(a)) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD), independent of other conventional risk factors. High Lp(a) levels are also independently associated with an increased risk of aortic stenosis progression rate. Plasma Lp(a) levels are primarily genetically determined by variation in the LPA gene coding for apo(a). All secondary prevention trials have demonstrated that the existing hypolipidemic therapies are not adequate to reduce Lp(a) levels to such an extent that could lead to a substantial reduction of ASCVD risk. This has led to the development of new drugs that target the mRNA transcript of LPA and efficiently inhibit Lp(a) synthesis leading to potent Lp(a) reduction. These new drugs are the ASO pelacarsen and the siRNAs olpasiran and SLN360. Recent pharmacodynamic studies showed that all these drugs potently reduce Lp(a) up to 98%, in a dose-dependent manner. Ongoing clinical trials will determine the Lp(a)-lowering efficacy, tolerability, and safety of these drugs as well as their potential effectiveness in reducing the ASCVD risk attributed to high plasma Lp(a) levels. We are not ready today to significantly reduce plasma Lp(a). Emerging therapies potently decrease Lp(a) and ongoing clinical trials will determine their effectiveness in reducing ASCVD risk in subjects with high Lp(a) levels.

Associations between composite dietary antioxidant index and estimated 10-year atherosclerotic cardiovascular disease risk among U.S. adults

Background

Atherosclerotic cardiovascular disease (ASCVD) remains the leading cause of death and disability both in U.S. and worldwide. Antioxidants have been proved critical in mitigating the development of atherosclerosis. This study aimed to investigate the associations between composite dietary antioxidant index (CDAI) and estimated 10-year ASCVD risk among U.S. adults.

Methods

Data extracted from the National Health and Nutrition Examination Survey were analyzed. A total of 10,984 adults aged 18 years and above were included in this study. CDAI was calculated based on the dietary intake reported in their 24-h recall interviews. The estimated 10-year ASCVD risk was calculated via Pooled Cohort Equations (PCE).

Results

After adjusting potential confounders, it was indicated that CDAI score was negatively correlated with 10-year ASCVD risk (OR 0.97, 95% CI 0.95-0.99). Stratify CDAI score by quartile, results showed that participants in the second, third, and fourth quartiles had lower ASCVD odds ratio (Q2: OR 0.87, 95% CI 0.69-1.09; Q3: OR 0.78, 95% CI 0.62-0.98; Q4: OR 0.74, 95% CI 0.59-0.94) than those in the first quartile (Q1, lowest CDAI score group), which was confirmed by the trend test as well (p < 0.05). Subgroup analyses stratified by sex, age, race/ethnicity, and smoking status did not show significant effect modification.

Conclusion

Higher dietary antioxidants intake is associated with lower ASCVD risk among U.S. adults, for which policymakers and healthcare professionals may consider increasing the consumption of antioxidant-rich foods as a preventive strategy for ASCVD.

Metformin Monotherapy Alters the Human Plasma Lipidome Independent of Clinical Markers of Glycemic Control and Cardiovascular Disease Risk in a Type 2 Diabetes Clinical Cohort

Type 2 diabetes (T2D) is a rising pandemic worldwide. Diet and lifestyle changes are typically the first intervention for T2D. When this intervention fails, the biguanide metformin is the most common pharmaceutical therapy. Yet its full mechanisms of action remain unknown. In this work, we applied an ultrahigh resolution, mass spectrometry-based platform for untargeted plasma metabolomics to human plasma samples from a case-control observational study of nondiabetic and well-controlled T2D subjects, the latter treated conservatively with metformin or diet and lifestyle changes only. No statistically significant differences existed in baseline demographic parameters, glucose control, or clinical markers of cardiovascular disease risk between the two T2D groups, which we hypothesized would allow the identification of circulating metabolites independently associated with treatment modality. Over 3000 blank-reduced metabolic features were detected, with the majority of annotated features being lipids or lipid-like molecules. Altered abundance of multiple fatty acids and phospholipids were found in T2D subjects treated with diet and lifestyle changes as compared with nondiabetic subjects, changes that were often reversed by metformin. Our findings provide direct evidence that metformin monotherapy alters the human plasma lipidome independent of T2D disease control and support a potential cardioprotective effect of metformin worthy of future study. SIGNIFICANCE STATEMENT: This work provides important new information on the systemic effects of metformin in type 2 diabetic subjects. We observed significant changes in the plasma lipidome with metformin therapy, with metabolite classes previously associated with cardiovascular disease risk significantly reduced as compared to diet and lifestyle changes. While cardiovascular disease risk was not a primary outcome of our study, our results provide a jumping-off point for future work into the cardioprotective effects of metformin, even in well-controlled type 2 diabetes.

Deciphering Complex Interactions in Bioactive Lipid Signaling

Lipids are usually viewed as metabolic fuel and structural membrane components. Yet, in recent years, different families of lipids able to act as authentic messengers between cells and/or intracellularly have been discovered. Such lipid signals have been shown to exert their biological activity via specific receptors that, by triggering distinct signal transduction pathways, regulate manifold pathophysiological processes in our body. Here, endogenous bioactive lipids produced from arachidonic acid (AA) and other poly-unsaturated fatty acids will be presented, in order to put into better perspective the relevance of their mutual interactions for health and disease conditions. To this end, metabolism and signal transduction pathways of classical eicosanoids, endocannabinoids and specialized pro-resolving mediators will be described, and the intersections and commonalities of their metabolic enzymes and binding receptors will be discussed. Moreover, the interactions of AA-derived signals with other bioactive lipids such as shingosine-1-phosphate and steroid hormones will be addressed.