LDL Oxidation Research Articles

Spirulina Unleashed: A Pancreatic Symphony to Restore Glycemic Balance and Improve Hyperlipidemia and Antioxidant Properties by Transcriptional Modulation of Genes in a Rat Model

Hyperlipidemia is the root cause of numerous chronic conditions, leading to high mortality rates around the globe. Spirulina (Arthrospira platensis) microalgae serve as a promising reservoir of bioactive compounds with diverse pharmacological properties. The current study examined the nutritional profile of spirulina powder in relation to strict glycemic control, specifically focusing on its potential to lower lipid levels. In an in vivo investigation, normal healthy male Wistar albino rats (n = 60) were divided into two groups: a negative control group (NC) of ten rats and a high-fat diet group (n = 50) that were fed a cholesterol-rich diet until their cholesterol levels reached or exceeded 250 mg/dL. Subsequently, the hypercholesterolemic rats were then randomly allocated to several treatment groups: a positive control (PC); a standard treatment diet (STD) involving fenofibrate at a dose of 20 mg/kg body weight; and three experimental groups (T1, T2, and T3) that received spirulina powder supplementation at doses of 300, 600, and 900 mg per kg body weight, respectively, for the period of 12 weeks. Blood samples were analyzed for oxidative stress biomarkers, insulin levels, lipid profiles, liver function, and expression of gene levels in the diabetogenic pathway. The study utilized spectrophotometric colorimetric methods to identify oxidative stress biomarkers, serum kit methods to measure lipid profiles and liver enzymes, and the assessment of qPCR for mRNA quantity. According to the research findings, spirulina powder has certain noteworthy features. It had the greatest quantity of chlorogenic acid (4052.90 µg/g) among seven phenolics and two flavonoid compounds obtained by HPLC-UV analysis. Furthermore, the proximate analysis demonstrated that spirulina is high in protein (16.45 ± 0.8%) and has a significant energy yield of 269.51 K-calories per 100 g. A maximal spirulina dose of 900 mg/kg/wt significantly lowered oxidative stress, cholesterol, triglyceride, low-density lipoproteins (LDL), and insulin levels (p ≤ 0.05). In contrast, high-density lipoprotein (HDL) and total antioxidant capacity (TAC) levels increased significantly (p ≤ 0.05) compared to all other groups, except the NC group. The study provides remarkable proof about the pharmacological impact of spirulina powders. Significant reductions (p ≤ 0.05) in liver enzymes {alanine aminotransferase (ALT) and aspartate aminotransferase (AST)} were observed across all treatment groups, with the exception of the NC, compared to the positive control. The treatment groups had significantly greater gene expression levels of INS-1, PDX-1, IGF-1, and GLUT-2 than the positive control group (p ≤ 0.05). These findings highlight spirulina’s potential as a long-term regulator of hyperglycemia in rat models with induced hyperlipidemia, owing to its phenolic bioactive components that serve as antioxidants.

Immune-Mediated Inflammatory Diseases, Dyslipidemia, and Cardiovascular Risk: A Complex Interplay.

Individuals with autoimmune inflammatory diseases, such as systemic lupus erythematosus, rheumatoid arthritis, and psoriasis, are at increased risk for cardiovascular disease. While these diseases share common features of systemic inflammation, the impact of individual autoimmune inflammatory conditions on circulating lipids and lipoproteins varies by specific disease, disease activity, and the immune-suppressing medications used to treat these conditions. A common feature observed in many autoimmune inflammatory diseases is the development of a proatherogenic dyslipidemic state, characterized by dysfunctional HDLs (high-density lipoproteins) and increased oxidation of LDLs (low-density lipoproteins). Various disease-modifying antirheumatic drugs also have complex and variable effects on lipids, and it is critical to take this into consideration when evaluating lipid-related risk in individuals with immune-mediated inflammatory conditions. This review aims to critically evaluate the current understanding of the relationship between immune-mediated inflammatory diseases and dyslipidemia, the underlying mechanisms contributing to atherogenesis, and the impact of various pharmacotherapies on lipid profiles and cardiovascular risk. We also discuss the role of lipid-lowering therapies, particularly statins, in managing residual risk in this high-risk population and explore the potential of emerging therapies with complementary anti-inflammatory and lipid-lowering effects.

High glucose enhanced lipoprotein(a) [Lp(a)] oxidation in a manner inhibited by eicosapentaenoic acid (EPA) in vitro

Abstract Background Elevated lipoprotein(a) (Lp(a)) levels are causally and independently associated with increased cardiovascular (CV) risk. Targeted molecular therapies are in development. Levels of oxidized Lp(a) were more predictive of CV events and endothelial dysfunction in type 2 diabetes than non-oxidized forms. EPA administered as icosapent ethyl (IPE) reduced CV events in statin-treated patients (REDUCE-IT) with diabetes and high CV risk. As a fatty acid with multiple conjugated double bonds, EPA inhibits lipoprotein oxidation by a potent lipid-centric scavenging mechanism. We therefore tested the effects of EPA on oxidation of Lp(a) and non-modified LDL under conditions of high glucose to mimic aspects of hyperglycemia in vivo. Methods Lp(a) was enriched to 41% of total ApoB-containing particles from patients with elevated levels by isopycnic centrifugation. Samples of Lp(a) and non-modified LDL were incubated under high glucose (200 mg/dL) conditions at 37°C for 30 min with EPA (50 µM). Samples were then subjected to copper sulfate-induced oxidation (20 µM) monitored by formation of malondialdehyde (MDA) via a colorimetric assay. Results Lp(a) enriched plasma underwent increased oxidation, peaking at 4 hr by 32-fold compared to baseline (0.37 ± 0.04 vs 12.27 ± 0.61 µM, p<0.001) under conditions of high glucose. Non-modified LDL also underwent oxidation in the presence of high glucose with a distinct rate compared to Lp(a), peaking after 3 h (0.28 ± 0.09 vs 10.91 ± 0.93 µM, p<0.001). EPA significantly inhibited both Lp(a) and LDL oxidation in a time-dependent manner. After peak oxidation was achieved in Lp(a) (4 h) and LDL (3 h), EPA inhibited oxidation by 57% (5.29 ± 0.25 µM, p<0.001) and 81% (2.12 ± 0.09 µM, p<0.001), respectively. Conclusions Under hyperglycemic conditions, EPA inhibited oxidation of Lp(a)-enriched plasma and non-modified LDL in a time-dependent manner. The activity of EPA may arise from its lipophilic properties and highly conjugated structure that scavenges free radicals in lipid-concentrated environments. The potent antioxidant activity of EPA may contribute to reduced CV risk in patients with diabetes and elevated Lp(a).

Oxidized Low-Density Lipoprotein and Its Role in Immunometabolism

Modified cholesterols such as oxidized low-density lipoprotein (OxLDL) contribute to atherosclerosis and other disorders through the promotion of foam cell formation and inflammation. In recent years, it has become evident that immune cell responses to inflammatory molecules such as OxLDLs depend on cellular metabolic functions. This review examines the known effects of OxLDL on immunometabolism and immune cell responses in atherosclerosis and several other diseases. We additionally provide context on the relationship between OxLDL and aging/senescence and identify gaps in the literature and our current understanding in these areas.

Massa Medicata Fermentata, a Functional Food for Improving the Metabolic Profile via Prominent Anti-Oxidative and Anti-Inflammatory Effects.

Massa Medicata Fermentata (MMF) is a naturally fermented product used to treat indigestion and increase stomach activity in traditional medicine. This study examined the ability of the hydrothermal extract of MMF to scavenge free radicals corresponding to biological oxidative stresses, further protecting essential biomolecules. The anti-inflammatory effects of MMF were evaluated in LPS-induced RAW264.7 macrophages and zebrafish. In addition, the effects of MMF on the body mass index (BMI) and cholesterol accumulation in adult zebrafish fed a high-cholesterol diet (HCD) for three weeks were examined. MMF prevented the DNA and lipid damage caused by oxidative stress, inhibited LDL oxidation, and reduced the expression of cytokines and related proteins (MAPK and NFκB), with prominent anti-oxidative pathway (NRF2-HO-1) activation properties. LPS-induced NO production was reduced, and the increase in BMI and TC caused by the HCD diet was suppressed by MMF in zebrafish embryos or adult zebrafish. The bioactive aglycone of quercetin may be contributing to the mechanisms of systemic effects. MMF has excellent antioxidant properties and is useful for improving inflammation status and metabolic profile, thus highlighting its potential as a healthy, functional food.

Extracellular Vesicles Contribute to Oxidized LDL-Induced Stromal Cell Proliferation in Benign Prostatic Hyperplasia.

Clinical and experimental evidence has linked Benign Prostatic Hyperplasia (BPH) with dyslipidemic and hypercholesterolemic conditions, though the underlying cellular mechanisms remain unclear. This study investigates the impact of dyslipidemia, specifically oxidized LDL (OxLDL), on prostatic stromal cell proliferation and the release of extracellular vesicles (EVs). Mice were fed a high-fat diet, and human prostatic stromal cells (HPSCs) were treated with OxLDL. Proliferation assays and EV characterization were performed to assess the role of EVs in BPH progression. Pro-atherogenic conditions significantly increased cell proliferation in both murine prostatic cells and HPSCs. Treatment with metformin effectively inhibited OxLDL-induced proliferation. Additionally, OxLDL stimulated the production and release of pro-proliferative EVs by HPSCs, which further promoted cellular proliferation. The findings suggest that dyslipidemia drives prostatic stromal cell proliferation and EV secretion, contributing to BPH progression. Metformin demonstrates potential as a therapeutic agent to mitigate these effects, offering insight into novel strategies for BPH management. This study highlights the complex interaction between dyslipidemia, cell proliferation, and extracellular communication in the context of BPH pathogenesis.

6828 Exploring Metabolomic Clues in Diabetic Retinopathy

Abstract Disclosure: M.W. Simonson: None. Y. Li: None. J.J. McAnany: None. B. Prasad: None. E.C. Hanlon: None. S. Pannain: None. B.T. Layden: None. E. Van Cauter: None. J.C. Park: None. S.J. Crowley: None. F.Y. Chau: None. K.K. Danielson: None. H. Chen: None. G.E. Chlipala: None. C. Martinez: None. S. Reutrakul: Speaker; Self; Eli Lilly & Company. Background: Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Metabolomics offers the possibility for novel biomarker discovery. The purpose of this study was to determine metabolomic differences that characterized patients with versus without DR. Methods: A total of 62 serum samples were collected from 36 type 2 diabetes (T2D) patients with DR and 26 T2D patients without DR, and analyzed via UPLC-MS. The metabolite data were normalized using median normalization. The differential expression of metabolites was compared among the groups using the limma package in R. The covariates (age, sex, BMI and sleep apnea severity) were accounted for by using a generalized linear model fitted to the data. Significantly different metabolites were filtered by an absolute log2 Fold Change (FC) of 1.5 or greater and Q values < 0.05. Results: Mean (SD) age for DR and no-DR group was 55 (±5.9) versus 54 (±6.7) years, while BMI was 33 (±5.8) versus 33 (±6.3) kg/m2 respectively. Both DR and no-DR groups were 58% female. A1C levels in DR group was marginally higher than in no-DR group (p=0.09). There were significant differences in metabolomic changes between DR versus no-DR, with 166 total differential metabolites after adjusting for covariates and filtering by FC. Notable metabolites included those involved in fatty acid metabolism, acyl carnitines, prostaglandins, and phospholipids. There was an overall upregulation of serum acyl carnitines in DR as compared to no-DR, including 2,6 dimethylheptanoyl carnitine (FC = 3.0) and cis-5-Tetradecenoylcarnitine (FC = 2.0). Additionally, there was a decrease in long chain fatty acids in DR as compared to no-DR, which included 6-hydroxypentadecanedioic acid (FC = -6.6), 10,16-dihydroxy-palmitic acid (FC = -6.0), and tetracosatetraenoyl CoA (FC = -6.1). The 11-beta prostaglandin F2 (11-PGF2) was increased in DR (FC = 1.9). Circulating phospholipids including lysophosphatidylcholine (22:2) (lysoPC) (FC = 1.8) and phosphatidylcholine (24:1/24:1) (PC) (FC = 5.9) were also significantly dysregulated. Conclusions: We identified a subset of metabolites that discriminate T2D patients with or without DR. The changes in acyl carnitines and long chain fatty acids may reflect mitochondrial dysfunction in DR. The presence of certain prostaglandins highlights the inflammatory environment which may facilitate DR progression. Increases in phospholipids such as lysoPC suggest an atherogenic state and higher LDL oxidation, while increases in PC may indicate altered lipogenesis in DR. These findings may serve as new potential serum biomarkers to promote efficient preventive care and provide mechanistic insight into understanding DR pathophysiology. Presentation: 6/2/2024

Pro-Inflammatory Signaling Cascade Markers, Oxidative Stress-Inflammatory Signaling Axis, and Chronic Total Occlusion of Tibial Artery in Elderly Patients Suffering from Occlusion of Coronary Arteries.

Oxidative response is a risk factor in the progression of arterial atherosclerosis. This research study aimed to examine the effects of oxidative response on atherosclerotic susceptibility as well as the development of arteriosclerosis occlusions of the tibial artery through pro-inflammatory mediator genes in elderly patients with occlusion of coronary arteries. We determined that oxidative stress biomarkers (Malondialdehyde-modified Low-density Lipoprotein (MDA-LDL), Oxidized Low-density Lipoprotein (Ox-LDL) as well as Heme Oxygenase- 1 (HO-1)] and the expressions of pro-inflammatory mediator genes [Toll-like Receptor 4 (TLR4), Nuclear Factor kappa-B (NF-κB), Myeloid Differentiating factor 88 (MyD88) and Growth Arrest-specific gene 6 (GAS6)] have an impact on the severity of arteriosclerosis occlusions of tibial artery in elderly patients suffering from occlusion of coronary arteries. Levels of MDA-LDL, Ox-LDL, HO-1, TLR4, NF-κB, MyD88, and GAS6 were increased in the occlusion of tibial arteries + two-vessel coronary occlusion group compared to the CON group and occlusion of tibial arteries + one-vessel coronary occlusion group, respectively (p < 0.001); they were also elevated in occlusion of tibial arteries + multiple-vessel coronary occlusion group compared to occlusion of tibial arteries + one-vessel coronary occlusion group and occlusion of tibial arteries + two-vessel coronary occlusion group, respectively (P < 0.001). This has indicated the key roles of oxidative stress and pro-inflammatory mediator genes in arteriosclerosis occlusions of tibial artery in elderly patients with occlusion of coronary arteries. Oxidative response may promote the expressions of inflammatory genes and enhance susceptibility to arteriosclerosis occlusions of the tibial artery in elderly patients with chronic total coronary occlusions.

Age-Related Effects of Olive Oil Polyphenol Ingestion on Oxidation of Low-Density Lipoprotein in Healthy Japanese Men: A Randomized Controlled Double-Blind Crossover Trial.

The function of olive oil polyphenols in suppressing the oxidation of low-density lipoprotein (LDL) is well-known in Europeans. However, it remains unclear whether olive oil polyphenols exert antioxidant effects in Japanese people. The objective of this study was to determine whether the ingestion of olive oil polyphenols suppresses LDL oxidation in the Japanese population and whether this effect depends on age. This randomized controlled double-blind crossover trial with a 2-week washout enrolled 80 healthy Japanese men aged 35-64 years. Participants ingested either 14 g of extra virgin olive oil containing 5.0 mg of olive oil polyphenols (test food) or 14 g of refined olive oil containing 0.3 mg of olive oil polyphenols (control food) for 3 weeks. The primary outcome was oxidized LDL (malondialdehyde-modified LDL; MDA-LDL). Subgroup analyses based on age (35-50 and 51-64 years) were also performed. In all of the participants (35-64 years), there were no significant differences in MDA-LDL between the control and test groups. However, in the 35-50 years subgroup, ingestion of olive oil polyphenols led to a significantly larger reduction in MDA-LDL as compared with the control group (p < 0.025). The significantly lower dietary total polyphenol intake of the 35-50 years subgroup compared to the 51-64 years subgroup suggests that the suppressive function of olive oil polyphenol intake on LDL oxidation in Japanese men is influenced by dietary habits and is more clearly demonstrated in the younger age population with a relatively low total polyphenol intake.

The Role of Inducible Nitric Oxide Synthase in Assessing the Functional Level of Coronary Artery Lesions in Chronic Coronary Syndrome.

Chronic coronary syndrome (CCS) is a long-term manifestation of coronary artery disease, marked by stable but recurring chest pain and myocardial ischemia due to the gradual buildup of atherosclerotic plaques in the coronary arteries. It is a metabolic disorder of coronary arteries characterized by oxidative stress, endothelial dysfunction, inflammation, and hyperlipidemia. The imbalance in oxidative-antioxidative status contributes to stable ischemic heart disease. Oxidative stress involves reactive oxygen and nitrogen species, leading to low-density lipoprotein (LDL) oxidation. Endothelial dysfunction, marked by reduced nitric oxide (NO) bioavailability, is an early onset of CCS, affecting vasodilation, cell proliferation, and inflammatory responses. Enzyme myeloperoxidase (MPO), traditionally considered protective, plays a dual role in initiating and progressing inflammatory diseases. MPO interacts with NO, modulating its catalytic activity. Elevated NO levels inhibit MPO through a reversible complex formation, preventing NO-induced inhibition by inducible nitric oxide synthase (iNOS). MPO also inactivates endothelial nitric oxide synthase (eNOS) and reacts with L-arginine, hindering NO synthesis. The interplay between MPO and NO significantly influences inflammation sites, impacting peroxidation rates and oxidation reactions. Peroxynitrite, a reactive species, contributes to nitration of tyrosine residues and lipid peroxidation. Mechanistic pathways suggest MPO enhances iNOS catalytic activity, influencing CCS development. iNOS, implicated in inflammation and atherosclerosis, is connected to NO regulation. This review analyzes the complex interplay of MPO, iNOS, and NO that affects plaque morphology, oxidative stress, and inflammation, contributing to atherosclerosis progression. Therefore, it is possible that the phenotypes of atherosclerotic plaques, focal and diffuse coronary artery disease, could be defined by the relationship between MPO and iNOS.

Association Between Circulating Oxidized LDL Cholesterol Levels and Premature Myocardial Infarction: A Case-Control Study

Background: Acute myocardial infarction (MI) occurs less frequently in younger individuals compared to older ones. The development of atherosclerotic plaque is primarily linked to oxidized low-density lipoprotein cholesterol (Ox-LDL). Objectives: This study aimed to investigate circulating Ox-LDL levels in individuals with premature MI and compare them to controls without a history of ischemic heart disease. Methods: In this case-control study, 35 patients who experienced a premature MI within 24 hours of symptom onset and met the age criteria (men ≤ 55 years and women ≤ 65 years) were recruited as cases. For comparison, 35 age and sex-matched individuals without a history of ischemic heart disease were selected as controls. Results: Analysis of circulating Ox-LDL levels revealed a significant elevation in patients with premature MI compared to controls (2.25 ± 1.78 vs. 1.04 ± 1.17 µg/dL; P = 0.002). Elevated Ox-LDL levels were associated with a 1.70-fold increased risk of premature MI compared to healthy individuals (95% CI: 1.16 - 2.49; P = 0.007). Conclusions: This study demonstrates an association between elevated Ox-LDL levels and premature MI, particularly in younger individuals. Measuring Ox-LDL levels may help predict heart attack risk, and interventions aimed at reducing these levels could potentially prevent atherosclerosis.

Development and validation of cardiometabolic risk predictive models based on LDL oxidation and candidate geromarkers from the MARK-AGE data

The predictive value of the susceptibility to oxidation of LDL particles (LDLox) in cardiometabolic risk assessment is incompletely understood. The main objective of the current study was to assess its relationship with other relevant biomarkers and cardiometabolic risk factors from MARK-AGE data. A cross-sectional observational study was carried out on 1089 subjects (528 men and 561 women), aged 40–75 years old, randomly recruited age- and sex-stratified individuals from the general population. A correlation analysis exploring the relationships between LDLox and relevant biomarkers was undertaken, as well as the development and validation of several machine learning algorithms, for estimating the risk of the combined status of high blood pressure and obesity for the MARK-AGE subjects. The machine learning models yielded Area Under the Receiver Operating Characteristic Curve Score ranging 0.783–0.839 for the internal validation, while the external validation resulted in an Under the Receiver Operating Characteristic Curve Score between 0.648 and 0.787, with the variables based on LDLox reaching significant importance within the obtained predictions. The current study offers novel insights regarding the combined effects of LDL oxidation and other ageing markers on cardiometabolic risk. Future studies might be extended on larger patient cohorts, in order to obtain reproducible clinical assessment models.

Design, Synthesis, and Characterization of Novel Cannabidiol-Based Derivatives with Potent Antioxidant Activities.

In recent years, extensive research has focused on cannabidiol (CBD), a well-studied non-psychoactive component of the plant-derived cannabinoids. CBD has shown significant therapeutic potential for treating various diseases and disorders, including antioxidants and anti-inflammatory effects. Due to the promising therapeutic effect of CBD in a wide variety of diseases, synthetic derivatization of this compound has attracted the attention of drug discovery in both industry and academia. In the current research, we focused on the derivatization of CBD by introducing Schiff base moieties, particularly (thio)-semicarbazide and aminoguanidine motifs, at the 3-position of the olivetolic ring. We have designed, synthesized, and characterized new derivatives based on CBD's framework, specifically aminoguanylhydrazone- and (thio)-semicarbazones-CBD-aldehyde compounds. Their antioxidant potential was assessed using FRAP and DPPH assays, alongside an evaluation of their effect on LDL oxidation induced by Cu2+ and AAPH. Our findings suggest that incorporating the thiosemicarbazide motif into the CBD framework produces a potent antioxidant, warranting further investigation.

In Vitro Modulation of Human Foam Cell Formation and Adhesion Molecules Expression by Ginger Extracts Points to Potential Cardiovascular Preventive Agents.

Recent findings from the World Heart Federation (WHF) reported a significant increase in cardiovascular disease (CVD)-related deaths, highlighting the urgent need for effective prevention strategies. Atherosclerosis, a key precursor to CVD, involves the accumulation of low-density lipoprotein (LDL) and its oxidation within the endothelium, leading to inflammation and foam cell formation. Ginger extracts, known for their antioxidative and anti-inflammatory properties, show promise in preventing CVD initiation by inhibiting LDL oxidation and reducing foam cell formation. Our results revealed that the active fractions in ginger extracts had antioxidative effects, particularly fractions D and E. Further research is needed to identify the active compounds in these fractions and understand their mechanisms of action. In this context, microfluidic models could offer insights into the effects of ginger on monocyte recruitment in a more physiologically relevant context. Overall, ginger extracts represent a potential novel treatment for preventing CVD initiation, but additional studies are necessary to identify the active molecules in these fractions.

Oxidised low-density lipoprotein and antibodies against oxidised low-density lipoprotein in patients with antiphospholipid syndrome.

Recurrent thrombosis is one of the main clinical features of antiphospholipid syndrome (APS), and recent studies revealed that APS shares similar pathophysiological mechanisms with atherosclerosis. Oxidised low-density lipoprotein (OxLDL) and antibodies against OxLDL (anti-OxLDL) are involved in the development of atherosclerosis. This study aims to investigate the clinical significance of OxLDL and anti-OxLDL in APS patients. One hundred and seventy APS patients and 39 healthy controls (HC) were enrolled. Clinical and laboratory data were collected from Clinical Data Center of Peking University People's Hospital. OxLDL and anti-OxLDL were detected using enzyme-linked immunosorbent assay. Among the 170 APS patients, 106 had isolated thrombotic APS. Compared with HC, APS patients exhibited higher titres of OxLDL [413.86 (220.11-853.67) ng/mL vs. 45.54 (0-105.98) ng/mL, p<0.001] and anti-OxLDL [107.62 (75.68-174.18) U/L vs. 44.13 (18.44-79.76) U/L, p<0.001]. Also, APS patients exhibited a higher positivity rate for OxLDL (88.2% vs. 5.1%, p<0.001) and anti-OxLDL (84.1% vs. 36.5%, p<0.001) compared to HC. APS patients with elevated levels of OxLDL had a higher rate of LAC positivity (68.0% vs. 45.0%, p=0.042). Furthermore, APS patients with positive anti-OxLDL demonstrated a higher occurrence of venous thrombosis (46.2% vs. 18.5%, p=0.008) and a lower rate of Coomb's test positivity (52.6% vs. 76.2%, p=0.049). Multivariate logistic regression revealed that anti-OxLDL positivity (OR 12.424, 95%CI 1.108-139.330, p=0.041) were risk factors for venous thrombotic APS. This study indicates that the presence of anti-OxLDL may serve as potential markers for venous thrombosis in APS patients. OxLDL and anti-OxLDL may function as valuable biomarkers for monitoring APS.

Increased vascular deposition of oxidized LDL in untreated juvenile dermatomyositis

BackgroundJuvenile dermatomyositis (JDM) is a systemic vasculopathy associated with metabolic derangements and possible increased risk for premature atherosclerosis. Oxidation of low-density lipoprotein (LDL) in the endothelium is an early step in atherosclerotic plaque formation. It is not known if oxidized LDL is altered in children with untreated JDM. The deposition of oxidized LDL in the vasculature of muscle biopsies (MBx) from patients with untreated JDM and pediatric controls was assessed.FindingsFrozen tissue sections of MRI-directed MBx from 20 female children with untreated JDM and 5 female controls were stained with DAPI and fluorescently labeled antibodies against von Willebrand factor (vWF) and LDL oxidized by copper (oxLDL). Blood vessels were identified by positive vWF staining, and total fluorescence of oxLDL within the vessel walls was measured. Children with untreated JDM had increased deposition of oxLDL in the walls of muscle vasculature compared to healthy children (difference in means ± SEM = 19.86 ± 8.195, p = 0.03). Within the JDM cohort, there was a trend towards increased oxLDL deposition with longer duration of untreated disease (r = 0.43, p = 0.06). There was no significant correlation found between oxLDL deposition and markers of acute JDM disease activity including disease activity scores or muscle enzymes.ConclusionsThis study found increased deposition of oxLDL within blood vessels of children with untreated JDM supporting the concern that these children are at increased risk for premature atherosclerosis from chronic exposure to vascular oxLDL. This study highlights the importance of early diagnosis and treatment initiation to ameliorate cardiovascular damage.

Abstract Tu020: Contrasting effect of Ox-PAPC and PC-KLH in atherosclerotic plaques or peripheral blood T cell, macropahges and dendritic cell activation

Background: Atherosclerosis is a chronic inflammation characterized by accumulation of immune cells, oxidized low density lipoprotein (OxLDL) and dead cells in the lesions, both of the latter have the hapten phosphorylcholine (PC) as an important antigen. PC is also exposed on microorganisms and other compounds and needs a carrier to be antigenic. Antibodies against PC (anti-PC) ameliorates deleterious effects of both OxLDL and dead cells. Oxidized-1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine (Ox-PAPC) is a major compound in the lipid moiety of OxLDL exposing PC. Methods: We studied effect of Ox-PAPC and PC with keyhole limpet cyanid (KLH) on T cells, dendritic cells (DC) and macrophages (MQ). We examined the influence of Ox-PAPC and PC conjugated to KLH (PC-KLH) on T cells, DC, and MQ from peripheral blood or atherosclerotic plaques. We investigated phospholipid and glutathione (GSH) levels in the blood plasma of healthy controls (n=30) and patients (n=30). Results: Ox-PAPC, in contrast to PAPC and PC-KLH, independently of DC, induced proinflammatory T cell activation, which was inhibited by mito tempo, inhibitor of reactive oxygen species (ROS). Ox-PAPC triggered inflammatory activities while reducing metabolic activities in T cells. PC-KLH, on the other hand, reduced CD86 and CD11C, proinflammatory cytokines, and induced anti-inflammatory IL-10 in DC. Ox-PAPC induced ROS, GSH, and proinflammatory MQ activation, inhibited by Mito tempo or GSH inhibitor. Additionally, Ox-PAPC, in the presence of PCSK9, elevated CD86 expression and lipid peroxidation. Patients exhibited higher GSH levels comapre to control groups, associated with phospholipid levels. Conclusions: The study reveals the differential effects of Ox-PAPC on various immune cell types, showcasing T cell activation independent of DC and heightened macrophage activation in the presence of PCSK9. Ox-PAPC-induced redox imbalance regulates T cell activation, apoptosis, and MQ activation, potentially rendering plaques more vulnerable and contributing to lesion formation and thus plaque rupture. In contrast, PC-KLH had anti-inflammatory effects, inducing anti-inflammatory cytokines from T cells, DC and MQ. PC-effects thus vary from proinflammatory to anti-inflammatory depending on presentation. Inhibition of OxPAPC effects by agents such as anti-PC could thus be anti-atherogenic, while on the other hand PC presented on a protein as KLH could be anti-atherogenic and anti-inflammatory itself.

Low-Density Lipoprotein Cholesterol to Triglyceride Ratio and Clinical Outcomes after Acute Ischaemic Stroke or Transient Ischaemic Attack.

Studies showed that low-density lipoprotein cholesterol (LDL-C) to triglyceride (TG) ratio could be used as a predictive parameter of low-density lipoprotein oxidation in vivo and the level of small dense LDL-C. However, whether LDL-C/TG ratio is associated with stroke prognosis remains unclear. We investigated the associations of LDL-C/TG ratio with outcomes in patients with acute ischaemic stroke (AIS) or transient ischaemic attacks (TIA) and explored whether it produced more predictive value than LDL-C and TG. Data were derived from the Third China National Stroke Registry (CNSR-III). Multivariable Cox regression for stroke recurrence, composite vascular events and all-cause death and logistic regression for the poor functional outcome (modified Rankin Scale score 3-6) were used. A total of 14123 patients were included. After adjusting for confounding factors, quartile 4 of LDL-C/TG ratio was associated with an increased risk of recurrent stroke (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.03-1.56), composite vascular events (HR,1.23; 95% CI, 1.00-1.52), death (HR,1.70; 95% CI, 1.13-2.54) and poor functional outcome (odds ratio, 1.34; 95% CI, 1.12-1.61) at 3 months follow-up compared with quartile 1. We also found that quartile 4 of LDL-C and TG was positively and negatively associated with poor functional outcome at 3 months, respectively. LDL-C/TG ratio performed better than LDL-C or TG in predicting clinical outcomes. LDL-C/TG ratio was associated with the risk of stroke recurrence, composite vascular events, death and poor functional outcome in patients with AIS or TIA.

Bezafibrate mitigates oxidized-low density lipoprotein (ox-LDL)-induced the attachment of monocytes to endothelial cells: An implication in atherosclerosis.

Oxidized forms of low-density lipoproteins (ox-LDL)-associated endothelial dysfunction and subsequent monocyte adhesion play an important role in the development of atherosclerosis (AS). Bezafibrate (BEZ) is a peroxisome proliferator-activated receptor (pan-PPAR) agonist licensed as a hypolipidemic drug. However, the effects of BEZ on endothelial dysfunction are less reported. In this study, we aim to investigate the protective effects of BEZ on ox-LDL-challenged vascular endothelial cells to evaluate its potential value in treating AS. Human aortic endothelial cells (HAECs) and THP-1 cells were used to establish an In Vitro AS model. Cell Counting Kit-8 (CCK-8) assay, Real-time PCR, Western blot analysis, and Enzyme-linked immunosorbent assay (ELISA) were used to test the data. As expected, treatment with BEZ suppressed the expression of vascular endothelial growth factor A (VEGF-A), tissue factor (TF), Interleukin 12 (IL-12), tumor necrosis factor (TNF-α), and monocyte chemoattractant protein-1 (MCP-1). BEZ was also found to inhibit ox-LDL-induced expression of the endothelial adhesion molecules vascular cellular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in HAECs. Correspondingly, BEZ prevented attachment of THP-1 monocytes to ox-LDL-incubated HAECs. Mechanically, BEZ was found to prevent NF-κB activation by reducing the levels of nuclear NF-κB p65 and inhibiting luciferase activity of NF-κB. Our study revealed the pharmacological function of BEZ in protecting endothelial dysfunction against ox-LDL, which may provide valuable insight for the clinical application of BEZ.

Circ_0005699 Expedites ox-LDL-Triggered Endothelial Cell Injury via Targeting miR-384/ASPH Axis.

Atherosclerosis (AS) is an inflammatory disease with multiple causes. Multiple circular RNAs (circRNAs) are known to be involved in the pathogenesis of AS. To explore the function and mechanism of circ_0005699 in oxidative low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) injury. Ox-LDL treatment restrained HUVECs viability, cell proliferation, and angiogenesis ability, and accelerated HUVECs apoptosis, inflammatory response, and oxidative stress. Circ_0005699 was up-regulated in the serum samples of AS patients and ox-LDL-induced HUVECs. Interference of circ_0005699 effectively rescued ox-LDL-induced injury in HUVECs. Additionally, miR-384 could bind to circ_0005699, and miR-384 depletion inverted the effects of circ_0005699 deficiency on ox-LDL-mediated HUVEC injury. Moreover, ASPH was a direct target of miR-384, and the enforced expression of ASPH overturned miR-384-induced effects on ox-LDL-induced HUVECs. Importantly, circ_0005699 regulated ASPH expression via sponging miR-384. Interference of circ_0005699 protected against ox-LDL-induced injury in HUVECs at least partly by regulating ASPH expression via acting as a miR-384 sponge.