Plasma ox-LDL Levels Research Articles

Ezetimibe treatment reduces oxidized low-density lipoprotein in biliary cirrhotic rats.

In liver cirrhosis, chronic inflammation is associated with an increase in oxidative stress, and subsequently an increase in the concentration of oxidized low-density lipoprotein (ox-LDL). Ezetimibe is a lipid-lowering agent with anti-inflammation and anti-oxidative stress activities. This study aimed to investigate the effect of ezetimibe treatment on ox-LDL in cirrhotic rats. Biliary cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). Sham-operated rats served as surgical controls. Ezetimibe (10 mg/kg/d) or vehicle was administered in the sham-operated or BDL rats for 4 weeks, after which hemodynamic parameters, biochemistry data, and oxidative stress were evaluated. Plasma and intrahepatic ox-LDL levels were also examined, and hepatic proteins were analyzed to explore the mechanism of ezetimibe treatment. The BDL rats had typical features of cirrhosis including jaundice, impaired liver function, hyperlipidemia, and elevated ox-LDL levels compared to the sham-operated rats. Ezetimibe treatment did not affect hemodynamics, liver biochemistry, or plasma lipid levels. However, it significantly reduced oxidative stress, plasma levels of ox-LDL, and tumor necrosis factor α. In addition, ezetimibe upregulated the hepatic protein expression of an ox-LDL scavenger (lectin-like ox-LDL rececptor-1), which resulted in reductions in intrahepatic ox-LDL and fat accumulation in the BDL rats. Nevertheless, ezetimibe treatment did not ameliorate hepatic inflammation or liver fibrosis. Ezetimibe reduced plasma and intrahepatic ox-LDL levels in the cirrhotic rats. Furthermore, it ameliorated intrahepatic fat accumulation and oxidative stress. However, ezetimibe did not alleviate hepatic fibrosis or inflammation in the biliary cirrhotic rats.

Modification of Peripheral Blood Flow and Angiogenesis by CO2 Water-Bath Therapy in Diabetic Skeletal Muscle with or without Ischemia.

Previously, it was shown that both blood flow and angiogenesis in the ischemic hind limb of diabetic rats were increased upon CO2 treatment for 4 weeks. In the present study, we have compared the effects of 6 weeks CO2 therapy in diabetic rats with or without peripheral ischemia. Diabetes was induced in rats by a tail vein injection of streptozotocin (65 mg/kg body weight), whereas peripheral ischemia was produced by occluding the femoral artery at 2 weeks of inducing diabetes. Both diabetic and diabetic-ischemic animals were treated with or without CO2 water-bath at 37 °C for 6 weeks (30 min/day; 5 days/week) starting at 2 weeks, after the induction of ischemia. CO2 treatment did not affect heart rate and R-R interval as well as plasma levels of creatine kinase, glucose, cholesterol, triglycerides and high density lipoproteins. Unlike the levels of plasma Ox-LDL, MDA and TNF-α, the levels of NO in diabetic group were increased by CO2 water-bath treatment. On the other hand, the levels of plasma Ox-LDL and MDA were decreased whereas that of NO was increased without any changes in TNF-α level in diabetic-ischemic animals upon CO2 therapy. Treatment of diabetic animals with CO2 increased peak, mean and minimal blood flow by 20, 49 and 43% whereas these values were increased by 53, 26 and 80% in the diabetic-ischemic group by CO2 therapy, respectively. Blood vessel count in diabetic and diabetic-ischemic skeletal muscles was increased by 73 and 136% by CO2 therapy, respectively. These data indicate that peripheral ischemia augmented the increase in blood flow and development of angiogenesis in diabetic skeletal muscle upon CO2 therapy. It is suggested that greater beneficial effects of CO2 therapy in diabetic-ischemic animals in comparison to diabetic group may be a consequence of difference of changes in the redox-sensitive signal transduction mechanisms.

1491-P: ER Stress Drives the VEGF Expression in Monocytic Cells by Mechanisms Involving CHOP/ROS/HIF-1alpha/NRF2 and NF-kappaB/p38 MAPK Pathways

Obesity is marked by metabolic inflammation and by metabolic impairment caused by increased endotoxin, free fatty acids, and vascular endothelial growth factor (VEGF) levels; and involves the endoplasmic reticulum (ER) stress as well. However, it remains unclear whether the ER stress can induce/amplify VEGF expression in metabolically-stressed monocytic cells; and if so, by which mechanism(s). To test this, metabolic stress was induced in THP-1 monocytic cells by treating cells separately with lipopolysaccharide (LPS), palmitic acid (PA), and oleic acid (OA), in presence/absence of ER stressor thapsigargin (TG). Gene expression of VEGF/ER stress markers was assessed by qRT-PCR, protein expression by ELISA, ROS by DCFH-DA assay, phosphorylation of HIF-1α, NF-κB, ERK1/2, and p38 MAPK by immunoblotting, and the insulin response in stressed cells by glucose-uptake assay. Regarding clinical analyses, adipose VEGF gene and protein expression was detected using qRT-PCR and IHC, respectively, while plasma hs-CRP, TNF-α, MDA, and OX-LDL levels were measured by ELISA. The experimental data show that a cooperative interaction between the metabolic and ER stresses led to the expression of VEGF, ROS, CHOP, ATF6, SOD2, and NRF2 (P˂0.05), as well as stimulated the CHOP and NRF2 promoter activities in reporter cells (P˂0.05). However, the glucose uptake was not impaired. The VEGF expression was dependent on phosphorylation of HIF-1α, NF-κB, and p38 MAPK; and the inhibitors of NF-κB/MAPK pathways as well as antioxidants or ROS scavengers suppressed the VEGF production. Further, individuals with obesity showed increased VEGF expression which associated positively with plasma levels of hs-CRP, TNF-α, MDA, and OX-LDL (P≤0.05). Overall, our findings support a cooperativity model in which the ER and metabolic stresses interact to augment VEGF expression in monocytic cells via the mechanisms involving CHOP/ROS/HIF-1α/NRF2 and NF-κB/p38 MAPK pathways. Disclosure S.A.K.Sindhu: None. F.Alzaid: None. F.Almulla: None. R.Ahmad: None. N.Akhter: None. A.Wilson: None. H.Arefanian: None. A.Al madhoun: None. R.S.Thomas: None. S.P.Kochumon: None. F.Alrashed: None. F.Bahman: None. Funding Kuwait Foundation for the Advancement of Sciences (RA2015-027, RA2010-003, RAHM-2019-022)

Cell-free hemoglobin-mediated oxidation of low-density lipoprotein (oxLDL) contributes to lung microvascular endothelial dysfunction during sepsis

Introduction: Disruption of the microvascular endothelial barrier is a critical pathological feature of sepsis-induced acute lung injury. Plasma cell-free hemoglobin (CFH) is elevated in approximately 80% of patients with sepsis and is independently associated with development of acute respiratory distress syndrome (ARDS) and mortality. Oxidized CFH (ferric, 3+) can oxidize low-density lipoprotein (oxLDL), which signals through its major endothelial receptor, the lectin-like oxidized LDL receptor 1 (LOX-1), to cause endothelial dysfunction through several pro-inflammatory pathways including activation of mitogen-activated protein kinases (MAPKs). However, little is known regarding whether LOX-1 receptor signaling leads to microvascular endothelial hyperpermeability or acute lung injury, especially in the context of sepsis. We hypothesized that oxidation of LDL by CFH contributes to lung microvascular endothelial barrier dysfunction and worse outcomes during sepsis through LOX-1 and downstream p38 MAPK. Methods: To test whether generation of oxLDL by CFH is associated with endothelial injury in clinical sepsis, circulating levels of CFH, oxLDL, and vascular injury marker sVE-cadherin were measured in 24 sepsis patients via ELISA and tested for association with development of ARDS. LDL was oxidized by combining LDL with CFH in a test tube overnight at 37°C and oxLDL was quantified by TBARS assay. In primary human lung microvascular endothelial cells (HLMVEC) transendothelial electrical resistance (TER), a measure of barrier dysfunction, was assessed by Electric Cell-substrate Impedance Sensing (ECIS). LOX-1 receptor was blocked using BI-0115 (Boehringer Ingelheim, 20 μM) and p38 MAPK was inhibited using NiPp (100 μM). Results: In sepsis patients, plasma oxLDL levels correlated with CFH (r=0.686, p=0.016) and sVE-cadherin (r=0.603, p=0.012), and tended to be higher in those who developed ARDS (38 U/L [IQR 27, 45] vs. 27 U/L [IQR 19, 35], p=0.1). Oxidation of LDL by CFH exacerbated HLMVEC barrier dysfunction compared to control, LDL, or CFH. Barrier dysfunction induced by CFH or oxLDL was attenuated by blocking the LOX-1 receptor or p38 MAPK. Conclusions: Increased plasma CFH and oxLDL are associated with vascular injury during clinical sepsis; one mechanism by which CFH may cause vascular hyperpermeability and sepsis-mediated lung injury is through oxidation of LDL which can drive signaling through the endothelial LOX-1 receptor and activation of p38 MAPK. NIH R35HL150783, R21GM144915, R01HL158906, R01HL164937, T32HL094296; Parker B. Francis Fellowship This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Discovery of Novel N-Hydroxy-1,2,4-oxadiazole-5-formamides as ASM Direct Inhibitors for the Treatment of Atherosclerosis.

Acid sphingomyelinase (ASM), which regulates sphingolipid metabolism and lipid signaling, has been considered as a new potential target for the treatment of atherosclerosis. In this study, a series of benzene-heterocyclic-based ASM inhibitors were rationally designed, synthesized, and screened for the first time. As a result, some compounds showed favorable inhibitory activity against recombinant human ASM. The detailed SARs are also discussed. Compound 4i revealed good pharmacokinetic data and in vivo inhibitory activity against ASM by reducing the level of ceramide in mice plasma and liver. Pharmacodynamic studies confirmed that 4i could lessen lipid plaques in the aortic arch and aorta and reduce plasma ceramide concentration and Ox-LDL levels. Moreover, 4i was found to significantly decrease LPS-induced and Ox-LDL-induced cell inflammation by regulating the levels of ceramide and sphingomyelin. Overall, this study preliminarily demonstrates that ASM may be an effective target against atherosclerosis for the first time.

Association between circulating oxidized OxLDL/LDL-C ratio and the severity of coronary atherosclerosis, along with other emerging biomarkers of cardiovascular disease in patients with type 2 diabetes

AimsThe aim of this study was to evaluate the association between circulating oxLDL/LDL-C ratio and the severity of coronary atherosclerosis, along with other emerging biomarkers of cardiovascular disease (CVD) in patients with type 2 diabetes. MethodsWe recruited 152 patients with type 2 diabetes for our study. ELISA measured the plasma levels of oxLDL and other biomarkers. The severity of coronary lesions was evaluated using Gensini scores, which were calculated based on results of coronary computed tomographic angiography (CCTA). All patients were allocated into four groups according to CCTA findings and Gensini score: normal group (score = 0), mild coronary atherosclerosis group (0 < scores ≤ 3), moderate coronary atherosclerosis group (3.01 ≤ scores ≤ 32.67) and severe coronary atherosclerosis group (32.68 ≤ scores ≤ 180). Association between the oxLDL/LDL-C ratio and the severity of coronary atherosclerosis were evaluated using logistic regression models. ResultsMultivariate logistic regression analysis showed that the oxLDL/LDL-C ratio was positively associated with severity of coronary atherosclerosis (OR 2.03, 95% CI 1.31–3.14, p < 0.01). Interleukin 33 (IL33) correlated positively with oxLDL/LDL-C ratio (r = 0.274, p < 0.01). However, vascular cell adhesion molecular-1 (VCAM-1) had similar trends with oxLDL/LDL-C ratio in these 4 groups. ConclusionsOxLDL/LDL-C ratio is considered as a potential biomarker in patients with diabetes for early recognition and intervention of severe coronary atherosclerosis, and will be more effective if tested IL33 and VCAM-1 at the same time.

Effects of PCSK-9 Inhibition by Alirocumab Treatments on Biliary Cirrhotic Rats.

Hyperlipidemia and oxidative stress with elevated oxidized low-density lipoprotein (ox-LDL) exacerbate hepatic inflammation and fibrosis. The plasma level of low-density lipoprotein (LDL) is controlled by proprotein convertase subtilisin/kexin 9 (PCSK9). Alirocumab is a monoclonal antibody that decreases LDL via inhibiting PCSK9 function. Apart from lipid-lowering effects, alirocumab exerts anti-inflammation, anti-angiogenesis and anti-oxidant effects. This study aims to investigate the impact of alirocumab treatment on common bile duct ligation (BDL)-induced biliary cirrhotic rats. After a 4-week treatment of alirocumab, the hemodynamic data, blood biochemistry, ox-LDL level, oxidative stress markers, severity of hepatic encephalopathy and abnormal angiogenesis of BDL rats were measured and compared to the control group. BDL rats presented cirrhotic pictures and elevated ammonia, total cholesterol, LDL and ox-LDL levels compared to the control group. Alirocumab decreased plasma levels of total cholesterol, LDL, and oxidative stress markers; however, it did not affect the hemodynamics, liver and renal biochemistry, and the plasma levels of ammonia and ox-LDL. The motor activities, portal-systemic collaterals and mesenteric vascular density were not significantly different between alirocumab-treated and control groups. In addition, it did not affect hepatic inflammation, intrahepatic angiogenesis, liver fibrosis and free cholesterol accumulation in the liver of BDL rats. In conclusion, PCSK9 inhibition by alirocumab treatment ameliorates hyperlipidemia and systemic oxidative stress in biliary cirrhotic rats. However, it does not affect the plasma level of ox-LDL, intrahepatic inflammation and fibrosis. In addition, PCSK9 inhibition has a neutral effect on abnormal angiogenesis and hepatic encephalopathy in biliary cirrhotic rats.

Cell‐free Hemoglobin‐Oxidized LDL Axis Contributes to Microvascular Endothelial Barrier Dysfunction and Poor Outcomes During Sepsis

IntroductionSepsis, a dysregulated host response to infection with high morbidity and mortality, is characterized by a systemic inflammatory response and widespread vascular hyperpermeability leading to edema, organ dysfunction, and death with no specific treatments. Disruption of the microvascular endothelial barrier is a critical pathological feature of sepsis‐induced organ dysfunction driven by circulating inflammatory mediators, oxidants, and proteolytic enzymes. Cell‐free hemoglobin (CFH) is one such factor, released from damaged red blood cells during sepsis due to their increased deformability and fragility. Though CFH is not detectable in healthy subjects, plasma CFH is elevated in patients with sepsis and independently associated with mortality. CFH contributes to endothelial dysfunction, but the signaling mechanisms are incompletely understood. CFH can oxidize circulating low‐density lipoproteins (oxLDL), which could potentiate endothelial barrier disruption. We hypothesized that elevated levels of CFH during sepsis are associated with increased oxLDL and contribute to microvascular endothelial barrier dysfunction through the oxLDL receptor, lectin‐like oxidized LDL receptor 1 (LOX‐1).MethodsCirculating levels of CFH and oxLDL were measured in sepsis patients. In human lung microvascular endothelial cells (HLMVECs), transendothelial electrical resistance (TER), a measure of barrier dysfunction, was assessed by Electric Cell‐substrate Impedance Sensing (ECIS).Results (Figure)In sepsis patients, plasma oxLDL levels correlated with CFH (r=0.686; p=0.016, n=12) and were higher in patients who died in hospital (33.24 U/L [IQR 28.08, 48.28] vs. 27.19 U/L [IQR 16.24, 38.24]; p=0.045, n=25). HLMVEC barrier dysfunction induced by CFH (p&lt;0.0001, n=6‐7) or oxLDL (p=0.002, n=4‐6) was attenuated by blocking the LOX‐1 receptor with small molecule inhibitor BI‐0115 (Boehringer Ingelheim, 20 µM; p=0.018 vs CFH, n=5; p=0.0002 vs oxLDL, n=6).ConclusionIncreased plasma CFH and oxLDL are associated with HLMVEC barrier dysfunction and poor clinical outcomes during sepsis; one mechanism by which CFH may cause vascular hyperpermeability during sepsis is through oxidation of LDL which can drive signaling through the LOX‐1 receptor.

Curcumin supplementation improves oxidative stress and inflammation biomarkers in patients undergoing hemodialysis: a secondary analysis of a randomized controlled trial.

Recent studies have shed light on the potential role of curcumin in mitigating inflammation in patients with chronic kidney disease (CKD). This study aimed to evaluate the effects of curcumin supplementation on plasma levels of markers of inflammation and oxidative stress in patients with CKD undergoing hemodialysis (HD). These are secondary exploratory analyses from a previous double-blind, randomized controlled pilot study registered under ClinicalTrials.gov Identifier no. NCT00123456. It included 28 hemodialysis patients from a previous study divided into two groups: curcumin group (receiving juice with 2.5g of turmeric 3×/week for 12weeks) and a control group. The TNF-α, IL-6 and Ox-LDL plasma levels were measured by sandwich enzyme immunoassays ELISA; lipid peroxidation was measured by the reaction between malondialdehyde (MDA) and thiobarbituric acid. After 12weeks of supplementation with curcumin, the TNF-α plasma levels were significantly reduced [from 15.0 (8.23-73.3) to 6.17 (1.11-55.0) pg/mL, p = 0.01]. 12weeks of treatment with curcumin in HD patients resulted in a reduction in the biomarker of inflammation (TNF-α), confirming our previous hypothesis that curcumin has an anti-inflammatory effect.

Meta-Analysis of Randomized Clinical Trials Evaluating Effectiveness of a Multivitamin Supplementation against Oxidative Stress in Healthy Subjects.

A meta-analysis has been widely applied to draw general conclusions using a set of studies with similar purposes and designs. This study aimed to perform a meta-analysis of six randomized placebo-controlled trials, independently conducted for the relationship between a plant-based multivitamin/mineral supplementation (PMS) and oxidative stress for 6 to 8 weeks, to provide overall estimates of those effects. In detail, linear mixed model analysis was first conducted on each study to obtain individual estimates; then, two types of meta-analysis were applied to combine the individual estimates from all available studies (overall meta-analysis) and region-specific studies (subgroup meta-analysis). In the meta-analysis, we selected 19 biomarker variables that overlapped in at least two studies and found 6 variables significant in at least one meta-analysis. The overall estimates of beta coefficients were 0.17 for vitamin C, 0.80 for vitamin B6, 0.46 for vitamin B12, 0.81 for folate, 0.36 for β-carotene, and −0.17 for oxidized LDL (ox-LDL). Subsequent association analysis revealed significant negative correlations between plasma free radical scavenging nutrients and plasma ox-LDL levels, indicating a general benefit of PMS in alleviating oxidative stress by providing exogenous oxidant scavengers.

Lectin-Like OLR1 3'UTR Rs1050286 Gene Polymorphism and Plasma Oxidized-LDL in Coronary Artery Disease and Their Relation to Cardiovascular Risk and Outcomes.

Oxidized low-density lipoprotein (ox-LDL) has an important role in the genesis of coronary atherosclerosis. Lectin-like ox-LDL receptor 1 (OLR1) contributes to the uptake and internalization of ox-LDL. Genetic polymorphisms have been associated with coronary artery disease (CAD). Here we explore the association of plasma levels of ox-LDL and 3' UTR OLR1 (rs1050286) SNP with CAD risk and in-hospital adverse outcomes. A case-control study enrolled 192 patients with ST-segment elevation myocardial infarction (STEMI), 100 patients with unstable angina, and 100 healthy controls. Baseline, clinical characteristics, and risk scores of the patients were determined. Plasma ox-LDL and other biochemical variables were measured. All subjects are genotyped for OLR1 (rs1050286) by RT-PCR with TaqMan SNP genotyping assay. Plasma ox-LDL was higher with enhanced sensitivity and specificity in identifying patients with STEMI and was found as a significant independent risk factor for CAD in those two groups. Levels of ox-LDL were increased with increasing poor prognostic factors in STEMI patients that are associated with an increased incidence of some adverse events and in-hospital mortality. Elevated STEMI risk was associated with T allele of OLR1 (rs1050286) (odds ratio of 4.9, 95% CI: 2.6-9.4, p< 0.001). STEMI patients who have T allele exhibited higher risk scores, coronary multivessel narrowing, and elevated incidence of in-hospital major adverse clinical events. These results suggest that plasma ox-LDL, as well as T allele of ORL-1 (rs1050286), is associated with the increased risk for developing STEMI and the associated adverse clinical outcomes.

The Degree of Plasma Oxidized Low-Density Lipoprotein Level Decrease Is Related to Clinical Outcomes for Patients with Acute Ischemic Stroke.

Objective To investigate the relationship between the decrease of plasma oxidized low-density lipoprotein (oxLDL) levels and clinical outcomes in patients with acute atherosclerosis-related ischemic stroke. Methods We recruited acute ischemic stroke patients within 3 days of onset consecutively. Plasma oxLDL levels were measured on the second day after admission and before discharge (10-14 days after stroke onset). Initial stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) scores, and infarct volume was measured using diffusion-weighted imaging (DWI) by the ITK-SNAP software. Clinical outcomes were evaluated by DWI volumes in the acute phase, neurological improvement at discharge, and favorable functional prognosis at 90 days. Logistic regression was performed to evaluate the association between oxLDL level decrease and clinical outcomes. Results 207 patients were enrolled in this study. Compared with the mild decrease of the oxLDL level group, patients with a significant decrease of the oxLDL level group were more likely to have a higher ratio of neurological improvement at discharge (55.07% vs. 14.49%, p < 0.01) and favorable functional prognosis at 90 days (91.30% vs. 55.07%, p < 0.01). In multivariable logistic regression, the degree of oxLDL level decrease was related to neurological improvement at discharge and favorable functional prognosis at 90 days (p < 0.01). Patients with significant decrease were more likely to have neurological improvement at discharge (OR = 7.92, 95% CI, 3.14-19.98, and p < 0.01) and favorable functional prognosis at 90 days (OR = 7.46, 95% CI, 2.40-23.23, and p < 0.01) compared to patients with mild decrease of oxLDL level. The DWI volumes in patients with different oxLDL level decrease groups had no statistical difference (p = 0.41), and the Spearman's rho between oxLDL level decrease and DWI infarct volumes was -0.03, but no statistical difference (p = 0.72). Conclusions The degree of oxLDL level decrease is related to neurological improvement at discharge and favorable functional prognosis at 90 days for patients with acute atherosclerosis-related ischemic stroke, but not with infarct volume in the acute phase.

Oxidative stress-responsive apoptosis-inducing protein in patients with heterozygous familial hypercholesterolemia.

Oxidative stress, an inducer of apoptosis, plays a critical role in ischemia/reperfusion injury and atherosclerosis. We previously identified an apoptosis-inducing ligand, the post-translationally modified secreted form of eukaryotic translation initiation factor 5A (eIF5A), 'oxidative stress-responsive apoptosis-inducing protein' (ORAIP). In this study, we investigated the role of ORAIP in patients with heterozygous familial hypercholesterolemia (HeFH), a leading cause of premature cardiovascular disease. We analyzed plasma ORAIP and oxidized low-density lipoprotein (oxLDL) levels in 60 patients with HeFH (60% male, 57.0 ± 13.6years of age) and 20 patients with LDL-C hypercholesterolemia (DL, 85% male, 64.1±13.3years of age). The coronary artery atherosclerosis from the patients with HeFH who had a coronary artery bypass graft was investigated by double immunostaining. The plasma ORAIP levels in the patients with HeFH were significantly elevated compared to those in the patients with DL (73.5 ± 46.0 vs. 48.3 ± 21.4ng/mL, p = 0.0277). The plasma oxLDL levels in HeFH patients were also elevated (156.8 ± 65.2 vs. 123.7 ± 46.6mg/dL, p = 0.0461) compared to those in DL patients and correlated with maxLDL-C levels (R = 0.4454, p = 0.00648). Double-immunostaining of ORAIP and oxLDL in the coronary artery from patients with HeFH who had a coronary artery bypass graft showed that ORAIP and oxLDL were colocalized with apoptotic vascular smooth muscle cells in the atherosclerotic plaque. ORAIP plays a role in the development of oxidative stress-induced atherosclerosis and may be an important therapeutic target for plaque rupture in patients with HeFH.

MO627ASSOCIATION OF OXIDIZED LDL CHOLESTEROL WITH MORTALITY AND PROGRESSION OF PROTEINURIC DIABETIC KIDNEY DISEASE

Abstract Background and Aims Oxidative modification of low-density lipoprotein (oxLDL) contributes to the pathogenesis and progression of oxidative stress (OS) and atherosclerosis in both Type 2 Diabetes Mellitus (T2DM) and Chronic Kidney Disease (CKD). Compared to normo-and micro-albuminuric, T2DM patients with macroalbuminuria have significantly higher plasma oxLDL levels. In this study we aimed to assess the possible predictive role of oxLDL for mortality and deterioration of renal function in a cohort of patients with proteinuric diabetic CKD. Method 91 patients with diabetic retinopathy, persistent proteinuria and eGFR below 90ml/min were recruited. At baseline, oxLDL, proteinuria and eGFR were assessed and patients were categorized according to median oxLDL (above or below 66.22 U/L). All patients were prospectively followed for a period of 10 years or the occurrence of a combined outcome of mortality or at least 30% decline in eGFR and/or progression to end stage renal disease (ESRD), requiring renal replacement therapy. At the end of the follow-up period, renal function was re-assessed with a new estimation of eGFR, using the CKD-EPI formula. We performed a statistical analysis with receiver operation curves (ROC) to further examine the possible effect of oxLDL on the percentage change in eGFR and proteinuria over time (calculated as ΔeGFR/baseline eGFR and Δproteinuria/baseline proteinuria respectively) and divided by the follow-up time. Results The mean age of the patients was 67.02±8.2 years, and the mean duration of T2DM was 14.5±8.0 years. At baseline, compared to the low, patients with high circulating oxLDL levels had significantly higher levels of triglycerides, higher diastolic blood pressure and lower eGFR (P=0.001, P=0.04 and P-0.013, respectively, Mann-Whitney test). After a 10-year follow up, 10/46 patients in the low and 20/45 patients in the high ox-LDL group presented the composite outcome. Kaplan-Meier curves (Figure 1) showed that patients with oxLDL levels above median (&amp;gt;66.22 U/L) presented a significantly higher risk for the outcome compared to the low oxLDL group (P=0.001, log-rank test). Univariate Cox proportional hazard analysis revealed that high circulating oxLDL levels were independent predictors of the composite endpoint (HR=3.42, 95%CI: 1.55-7.56, P=0.002). After adjustment for all factors that were associated with the outcome in univariate models (baseline proteinuria, serum albumin, duration of T2DM and triglycerides), multivariate Cox analysis showed that the association between high oxLDL levels and the study endpoint remained significant (HR=3.76, 95%CI: 1.52-9.27, P=0.004). At ROC analysis the area under the curve (AUC) for oxLDL to identifying progressor patients was 0.68 (95% CI: 0.56-0.80, P=0.005). Of note, this AUC was virtually identical to that of baseline proteinuria. OxLDL failed to show any association with the change of proteinuria over time. Conclusion Circulating ox-LDL might play an important role in the progression of proteinuric DKD.

Effects of Pitavastatin on Lipoprotein Subfractions and Oxidized Low-density Lipoprotein in Patients with Atherosclerosis.

It has been demonstrated that pitavastatin can significantly reduce low-density lipoprotein (LDL) cholesterol (LDL-C), but its impact on lipoprotein subfractions and oxidized low-density lipoprotein (oxLDL) has not been determined. The aim of the present study was to investigate the potential effects of pitavastatin on subfractions of LDL and high-density lipoprotein (HDL) as well as oxLDL in untreated patients with coronary atherosclerosis (AS). Thirty-six subjects were enrolled in this study. Of them, 18 patients with AS were administered pitavastatin 2 mg/day for 8 weeks and 18 healthy subjects without therapy served as controls. The plasma lipid profile, lipoprotein subfractions and circulating oxLDL were determined at baseline and 8 weeks respectively. The results showed that pitavastatin treatment indeed not only decreased LDL-C, total cholesterol (TC), triglycerides (TG) and apolipoprotein B (ApoB) levels, and increased HDL cholesterol (HDL-C), but also reduced the cholesterol concentration of all of the LDL subfractions and the percentage of intermediate and small LDL subfractions. Meanwhile, pitavastatin could decrease plasma oxLDL levels. Furthermore, a more close correlation was found between oxLDL and LDL-C as well as LDL subfractions after pitavastatin treatment. We concluded that a moderate dose of pitavastatin therapy not only decreases LDL-C and oxLDL concentrations but also improves LDL subfractions in patients with AS.

Correlation of Moderate-Intensity Physical Exercise on Irisin, Oxidized-LDL and HDL Level in ≥50 Years Old Obese Men

BACKGROUND: Irisin is secreted by our muscle during physical exercise, which has been recently studied to be linked with lipid metabolism. The aim of this study was to investigate the role of irisin that interact with the oxidized-low density lipoprotein (ox-LDL) and high density lipoprotein cholesterol (HDL-C) levels that are affected by moderate intensity exercise in obese men aged ≥50 years.METHODS: This was a cross-sectional study with 70 obese men whose age ≥50 years old as participants. Participants were classified into two groups of men with and without physical exercised, based on American College of Sports Medicine (ACSM). Irisin and ox-LDL plasma levels were analyzed using enzyme-linked immunosorbent assay (ELISA), meanwhile the HDL-C serum level was analyzed using homogenous enzymatic methods.RESULTS: The result showed an association between the duration of physical exercise per week and irisin level (R=0.584, p&lt;0.01), also between the duration of physical excercise per week and ox-LDL level (R=-0.274, p&lt;0.05). Meanwhile, there was a negative association between irisin levels and ox-LDL (R=-0.294, p&lt;0.05). Irisin indicated to be correlated with HDL-C (R=0.215, p&gt;0.05).CONCLUSION: Moderate-intensity physical exercise may decrease cardiovascular risk and improve the quality of life among obese subjects aged ≥50 years old, which was indicated by the decrease of ox-LDL and the increase of irisin level. In addition, it can be concluded that the higher the irisin level showed the lower levels of ox-LDL and higher level of HDL-C.KEYWORDS: obesity, elderly, irisin, ox-LDL, HDL-C, physical exercise

PF420 RESULTS OF A PROSPECTIVE MULTICENTER STUDY ON PRO‐ATHEROTHROMBOTIC EFFECT INDUCED BY TYROSINE‐KINASE INHIBITORS FOR FIRST‐LINE TREATMENT OF CML PTS (KIARO TRIAL)

Background:Tyrosine kinase inhibitors (TKI) revolutionized treatment and prognosis of chronic myeloid leukemia (CML), but some patients (pts) still suffer from potentially severe TKI‐related toxicity. Of particular relevance is cardiovascular (CV) toxicity, mostly associated to Nilotinib (NILO) and Ponatinib. In a previous retrospective, cross‐sectional, multicenter study we confirmed a higher CV risk for pts treated with NILO, particularly those harboring the unfavorable OLR1 genetic polymorphism and we found a NILO‐associated pro‐inflammatory/oxidative effect, with increased IL6/IL10 and TNFα/IL10 ratios and levels of oxidized LDL (oxLDL) compared to Imatinib (IMA). We here report clinical, genetic and serologic results of a prospective multicenter Italian trial including CML pts treated with any of current first‐line TKIs (IMA, NILO, DASA).Aims:(1) to assess CV toxicity in CML pts in which first‐line TKI choice was made according to current CV risk guidelines (2) to assess pts’ genetic predisposition to CV events (3) to confirm a pro‐oxidative/inflammatory effect induced by NILO during treatment.Methods:A clinical CV risk score (S) was calculated using the algorithm from the European SCORE project. Integrating clinical with genetic information from 12 Single Nucleotide Polymorphisms (SNPs) associated with CV risk (ANRIL, SORT1, MIA3, CXCL12, MRPS6, PHATCR1, WDR12, LDLR, MRAS, CYP17A1, OLR1, IL10) an integrated score (IS) was obtained. CV‐relevant clinical and biological parameters were collected at specific timepoints (diagnosis, +1, +3, +6, +12 months) together with blood samples for IL6, IL10, TNFα and oxLDL plasma levels assessment.Results:Between September 2013 and September 2018, 177 newly‐diagnosed CML pts starting either IMA, NILO or DASA treatment, entered this study. After a median follow‐up of 22.4 months (range: 35 days – 5.4 years), a CV event has occurred in 5 pts, with a median time to event of 15 months (range: 44 days – 31.4 months). This accounts for an incidence of 5.9 per 1000 patient‐year, superior to that of a general age‐ and sex‐matched population (3.85 per 1000 patient‐year, OR 3.27, 95%CI 2.16–4.63; p = 0.013). Pts treated with NILO had lower CV risk at diagnosis (S = 6.9 ± 2.8) compared to those treated with DASA (S = 8.1 ± 3.2; p = 0.042) or IMA (S = 9.9 ± 4.9; p = 0.019). Nonetheless, 3/57 (5.2%) NILO‐treated pts developed CV toxicity, as opposed to 1/83 (1.2%) IMA‐treated (HR 2.9, 95% CI 1.8–4.4; p = 0.021) and 0 out of 37 DASA‐treated pts. One CV event occurred in a patient treated with first‐line IMA 23 months after being switched to Bosutinib, and therefore was not attributed to IMA.Levels of anti‐inflammatory cytokine IL10 were higher after 6 and 12 months of IMA or DASA compared to NILO. Also IL6/IL10 and TNFα/IL10 ratios in IMA‐ and DASA‐treated pts were lower compared to NILO‐treated pts. Increased levels of oxidation marker oxLDL were observed after 12 months of NILO, but not during IMA or DASA treatment. The few CV events registered did not allow for any correlation between genetic polymorphisms and increased CV risk in our population.Summary/Conclusion:This study confirms a higher CV risk for pts treated with NILO, even in a contemporary setting where pts were carefully selected for having a low pre‐treatment CV risk. This may be a consequence of a NILO‐induced pro‐inflammatory/oxidative status, as shown by reduced levels of IL10 and increased levels of oxLDL in pts treated with NILO. A longer follow up is necessary to identify possible specific genetic polymorphisms conferring higher CV risk in this population of CML pts treated with TKI.image

Oxidized low-density lipoprotein (oxLDL) supports Mycobacterium tuberculosis survival in macrophages by inducing lysosomal dysfunction

Type 2 diabetes mellitus (DM) is a major risk factor for developing tuberculosis (TB). TB-DM comorbidity is expected to pose a serious future health problem due to the alarming rise in global DM incidence. At present, the causal underlying mechanisms linking DM and TB remain unclear. DM is associated with elevated levels of oxidized low-density lipoprotein (oxLDL), a pathologically modified lipoprotein which plays a key role during atherosclerosis development through the formation of lipid-loaded foamy macrophages, an event which also occurs during progression of the TB granuloma. We therefore hypothesized that oxLDL could be a common factor connecting DM to TB. To study this, we measured oxLDL levels in plasma samples of healthy controls, TB, DM and TB-DM patients, and subsequently investigated the effect of oxLDL treatment on human macrophage infection with Mycobacterium tuberculosis (Mtb). Plasma oxLDL levels were significantly elevated in DM patients and associated with high triglyceride levels in TB-DM. Strikingly, incubation with oxLDL strongly increased macrophage Mtb load compared to native or acetylated LDL (acLDL). Mechanistically, oxLDL -but not acLDL- treatment induced macrophage lysosomal cholesterol accumulation and increased protein levels of lysosomal and autophagy markers, while reducing Mtb colocalization with lysosomes. Importantly, combined treatment of acLDL and intracellular cholesterol transport inhibitor (U18666A) mimicked the oxLDL-induced lysosomal phenotype and impaired macrophage Mtb control, illustrating that the localization of lipid accumulation is critical. Collectively, these results demonstrate that oxLDL could be an important DM-associated TB-risk factor by causing lysosomal dysfunction and impaired control of Mtb infection in human macrophages.

Sortilin promotes macrophage cholesterol accumulation and aortic atherosclerosis through lysosomal degradation of ATP-binding cassette transporter A1 protein.

Sortilin is closely associated with hyperlipidemia and the risk of atherosclerosis (AS). The role of sortilin and the underlying mechanism in peripheral macrophage are not fully understood. In this study, we investigated the effect of macrophage sortilin on ATP-binding cassette transporter A1 (ABCA1) expression, ABCA1-mediated cholesterol efflux, and aortic AS. Macrophage sortilin expression was upregulated by oxidized low-density lipoproteins (ox-LDLs) in both concentration- and time-dependent manners. Its expression reached the peak level when cells were incubated with 50μg/ml ox-LDL for 24h. Overexpression of sortilin in macrophage reduced cholesterol efflux, leading to an increase in intracellular total cholesterol, free cholesterol, and cholesterol ester. Sortilin was found to bind with ABCA1 protein and suppress macrophage ABCA1 expression, resulting in a decrease in cholesterol efflux from macrophages. The inhibitory effect of sortilin in cholesterol efflux was partially reversed by treatment with chloroquine, a lysosomal inhibitor. On the contrary, the ABCA1 protein level and ABCA1-mediated cholesterol efflux is increased by sortilin short hairpin RNA transfection. The fecal and biliary cholesterol 3H-sterol from cholesterol-laden mouse peritoneal macrophage was reduced by sortilin overexpression through lentivirus vector (LV)-sortilin in low-density lipoprotein receptor knockout mice, which was prevented by co-treatment with chloroquine. Treatment with LV-sortilin reduced plasma high-density lipoprotein and increased plasma ox-LDL levels. Accordingly, aortic lipid deposition and plaque area were exacerbated, and ABCA1 expression was reduced in mice in response to infection with LV-sortilin alone. These effects of LV-sortilin were partially reversed by chloroquine. Sortilin enhances lysosomal degradation of ABCA1 protein and suppresses ABCA1-mediated cholesterol efflux from macrophages, leading to foam cell formation and AS development.

Daily consumption of a dark-roast coffee for eight weeks improved plasma oxidized LDL and alpha-tocopherol status: A randomized, controlled human intervention study

Abstract Scope Coffee consumption is widely recognized to improve the antioxidant status. We hypothesized a dark-roast coffee to reduce plasma oxidized LDL (oxLDL) and to improve alpha-tocopherol concentrations. Methods and results After a 4 week, coffee-free run-in period, 86 healthy, randomized volunteers completed either a control (CTRL) or coffee (COFF) intervention in which either 750 mL water (CTRL) or coffee (COFF) were consumed daily for 8 weeks. Blood samples were taken at the begin and after the intervention. Mean changes in oxidized LDL concentrations after coffee consumption (−0.47 ± 15.4 U/L) differed from those of the CTRL-G (5.69 ± 18.8 U/L, p Conclusion Improved plasma alpha-tocopherol levels and reduced levels of plasma oxLDL after 8 week consumption of a dark-roast coffee rich in N-methylpyridinium are hypothesized to be caused by coffee-induced lipolysis, resulting in increased alpha-tocopherol mobilisation.