Impact of oxidized low density lipoprotein on vascular cells

Interaction mechanism of lipid metabolism remodeling, oxidative stress, and immune response mediated by Epinephelus coioides SRECII

Scavenger receptors (SRs), a category of pattern recognition receptors primarily expressed on the surface of myeloid cells, play pivotal roles in oxidation response and lipid metabolism. However, current research on Scavenger Receptor class F type II (SRECⅡ) revolves around Van Den Ende-Gupta Syndrome (VDEG), the potential function of SRECII, particularly in regulating lipid metabolism and oxidative stress processes, remains elusive. Herein, we elucidate that SRECII from Epinephelus coioides (EcSRECII) may modulate fatty acid oxidation and oxidative stress levels via interactions with lipoprotein particles. EcSRECII mediates the internalization of oxidized Low-Density Lipoprotein (oxLDL), thereby inducing lipid accumulation. This process upregulates the expression of genes associated with lipid synthesis and concurrently suppresses those involved in lipolysis. Additionally, EcSRECII exacerbates the production of Reactive Oxygen Species (ROS) following oxLDL exposure, evidenced by significantly heightened activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), increased accumulation of malondialdehyde (MDA), and enhanced total antioxidant capacity (T-AOC). Furthermore, we reveal that EcSRECII-mediated oxLDL internalization culminates in apoptosis and necrosis in GS cells. Ultimately, we demonstrate that EcSRECII augments oxLDL-induced cellular oxidative stress and inflammatory responses, effects that are notably mitigated by EcSRECII knockdown or pretreatment with the fatty acid synthase (FAS) inhibitor C75. Collectively, our study underscores the role of EcSRECII in facilitating oxLDL internalization and subsequent lipid metabolism remodeling, thereby participating in the intricate regulation of intracellular oxidative stress and immune responses.

OxLDL/LOX-1 mediated sex, age, stiffness, and endothelial dependent alterations in mouse thoracic aortic vascular reactivity

Elevated plasma levels of oxidized low-density lipoprotein (oxLDL) are a risk factor and key component that accelerates and worsens cardiovascular disease fueling inflammation, plaque buildup and vascular damage. OxLDL can elicit its detrimental action via lectin-like oxLDL receptor 1 (LOX-1). In this study, we determined whether oxLDL, via LOX-1, alters aortic vascular reactivity and determined if sex and age differences exist. Thoracic aortic endothelium-intact or -denuded ring segments were isolated from 7 to 12 months old intact C57BL/6J female and male mice and pre-incubated with oxLDL ex vivo (50ug/dL; 2 h). Using wire myography, cumulative concentration-response curves to phenylephrine (PE) were generated to determine contractile responses. From these curves, the EC50 was determined and used to contract rings to assess acetylcholine (ACh) dependent relaxation. Calculated aortic stiffness and remodeling were also assessed. BI-0115 (10 μ M; selective LOX-1 inhibitor) was used to determine LOX-1 dependence. We observed differential sex, age, endothelial cell, and LOX-1 dependent alterations to the efficacy of PE-induced contractile responses and ACh-mediated vasorelaxation in thoracic aortic rings following oxLDL exposure. Additionally, we observed a distinct sex and age effect on thoracic aortic stiffness following exposure to oxLDL. There was also a sex effect on calculated vessel diameter, as well as an age effect on oxLDL-mediated aortic remodeling that was LOX-1 dependent. Thus, LOX-1 inhibition and the resulting attenuation of oxLDL/endothelial-mediated alterations in aortic function suggests that there are differential sex differences in the role of oxLDL/LOX-1 in the thoracic aorta of middle-aged male and female mice. NEW and NOTEWORTHY. We investigated the effects of oxLDL via the LOX-1 receptor on murine thoracic aortic vasoreactivity, stiffness, and remodeling across age and sex. Acute exposure to oxLDL led to altered vasoreactivity, endothelial dysfunction, and changes in aortic stiffness and remodeling. These effects were in-part age, sex, endothelial, and LOX-1 dependent. This study reveals potential complex interactions in oxLDL/LOX-1-mediated vascular responses that could serve as potential therapeutic intervention for vascular diseases such as atherosclerosis and stroke.

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

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

GLP-1 receptor agonists and atherosclerosis protection: the vascular endothelium takes center stage

Atherosclerotic cardiovascular disease is a chronic condition that often copresents with type 2 diabetes and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are incretin mimetics endorsed by major professional societies for improving glycemic status and reducing atherosclerotic risk in people living with type 2 diabetes. Although the cardioprotective efficacy of GLP-1RAs and their relationship with traditional risk factors are well established, there is a paucity of publications that have summarized the potentially direct mechanisms through which GLP-1RAs mitigate atherosclerosis. This review aims to narrow this gap by providing comprehensive and in-depth mechanistic insight into the antiatherosclerotic properties of GLP-1RAs demonstrated across large outcome trials. Herein, we describe the landmark cardiovascular outcome trials that triggered widespread excitement around GLP-1RAs as a modern class of cardioprotective agents, followed by a summary of the origins of GLP-1RAs and their mechanisms of action. The effects of GLP-1RAs at each major pathophysiological milestone of atherosclerosis, as observed across clinical trials, animal models, and cell culture studies, are described in detail. Specifically, this review provides recent preclinical and clinical evidence that suggest GLP-1RAs preserve vessel health in part by preventing endothelial dysfunction, achieved primarily through the promotion of angiogenesis and inhibition of oxidative stress. These protective effects are in addition to the broad range of atherosclerotic processes GLP-1RAs target downstream of endothelial dysfunction, which include systemic inflammation, monocyte recruitment, proinflammatory macrophage and foam cell formation, vascular smooth muscle cell proliferation, and plaque development.

Glucose variability: a new risk factor for cardiovascular disease

AIMS AND DATA SYNTHESIS

Glucose variability (GV) is increasingly considered an additional index of glycemic control. Growing evidence indicates that GV is associated with diabetic vascular complications, thus being a relevant point to address in diabetes management. GV can be measured using various parameters, but to date, a gold standard has not been identified. This underscores the need for further studies in this field also to identify the optimal treatment.

CONCLUSIONS

We reviewed the definition of GV, the pathogenetic mechanisms of atherosclerosis, and its relationship with diabetic complications.

Amelioration of atherosclerosis in ox-LDL induced HUVEC by sulfated polysaccharides from Gelidium crinale with antihypertensive activity

Red algal polysaccharide is a good potential medical resource. Different red algal polysaccharides have different structural characteristics and rich biological activities. Previous studies have identified some structural information of sulfated polysaccharide (GNP, 25.8 kDa) from red algae, Gelidium crinale and found that GNP has excellent anti-inflammatory, antioxidant and anti-tumor activities. On this basis, this study investigated the effect of GNP on atherosclerosis, which is closely related to antioxidant and anti-inflammatory mechanisms and usually coexists and interacts with hypertension. This study investigated the inhibitory activity of GNP on angiotensin-converting enzyme (ACE) and its mechanism on oxidized low-density lipoprotein (ox-LDL)-induced HUVEC atherosclerosis. The results showed that GNP inhibits the up-regulation of cell adhesion molecules and oxidized low-density lipoprotein receptor-1 (LOX-1). GNP can regulate mitogen-activated protein kinases (MAPK), nuclear factor kappa B (NF-κB) and PI3K/AKT signal pathways, inhibit apoptosis, invasion and migration. Meanwhile, GNP (IC₅₀ = 269.2 μg/mL) antagonizes ACE by competitive binding mode, and it can reduce systolic blood pressure (SBP) of spontaneously hypertensive rats (SHR). It provides a theoretical basis for GNP as a potential substance for the prevention and treatment of atherosclerosis.

Influence of Chlorhexidine and Cetylpyridine on Periodontal Status and Indicators of Oxidative Stress in Patients with Type 1 Diabetes

Objective: One of the treatment goals in type 1 diabetes and periodontitis is to address chronic inflammation to prevent the development of neurovascular complications. The aim of this study was to assess the local anti-inflammatory effects of chlorhexidine digluconate and cetylpyridine chloride on periodontal status and indicators of oxidative stress in saliva in patients with type 1 diabetes. Materials and Methods: A total of 42 subjects aged 27 (interquartile range, IQR 22–35) years, with type 1 diabetes for a duration of 12 (IQR 9–18) years, and glycated hemoglobin 8.05 (IQR 7.1–9.4)% were included. Patients were examined twice—initially, and after 14 days of using toothpaste with chlorhexidine and cetylpyridine. Clinical examination of gingival tissues was performed. Certain oxidative stress markers (TP, TEAC, TBARS, AOPP) were measured in the saliva samples. Results: There were significant changes in clinical indicators of periodontal status before and after the application of the toothpaste (API before 0.35 (0.24–0.65) vs. API after 0.265 (0.18–0.39), p = 0.03; SBI before 0.07 (0.04–0.15) vs. SBI after 0.035 (0-0.06), p = 0.002; GI before 0.88 (0.46–1) vs. GI after 0.67 (0.25–1), p = 0.0008). The concentration of saliva TBARS decreased (p = 0.00005) and TEAC increased (p = 0.09). Conclusion: Proper oral hygiene supported by antibacterial chemicals may improve the periodontal status and reduce inflammation.

OxLDL as an Inducer of a Metabolic Shift in Cancer Cells

Recent evidence established a link between disturbed lipid metabolism and increased risk for cancer. One of the most prominent features related to disturbed lipid metabolism is an increased production of oxidized low-density-lipoproteins (oxLDL), which results from elevated oxidative stress. OxLDL is known to have detrimental effects on healthy cells and plays a primary role in diseases related to the metabolic syndrome. Nevertheless, so far, the exact role of oxLDL in cancer cell metabolism is not yet known. To examine changes in metabolic profile induced by oxLDL, pancreatic KLM-1 cells were treated with oxLDL in a concentration- (25 or 50 µg/ml) and/or time-dependent (4 hr or 8 hr) manner and the impact of oxLDL on oxygen consumption rates (OCR) as well as extracellular acidification rates (ECAR) was analyzed using Seahorse technology. Subsequently, to establish the link between oxLDL and glycolysis, stabilization of the master regulator hypoxia-inducible factor 1-alpha (HIF-1α) was measured by means of Western blot. Furthermore, autophagic responses were assessed by measuring protein levels of the autophagosomal marker LC3B-II. Finally, the therapeutic potential of natural anti-oxLDL IgM antibodies in reversing these effects was tested. Incubation of KLM-1 cells with oxLDL shifted the energy balance towards a more glycolytic phenotype, which is an important hallmark of cancer cells. These data were supported by measurement of increased oxLDL-mediated HIF-1α stabilization. In line, oxLDL incubation also increased the levels of LC3B-II, suggesting an elevated autophagic response. Importantly, antibodies against oxLDL were able to reverse these oxLDL-mediated metabolic effects. Our data provides a novel proof-of-concept that oxLDL induces a shift in energy balance. These data not only support a role for oxLDL in the progression of cancer but also suggest the possibility of targeting oxLDL as a therapeutic option in cancer.

Irisin in atherosclerosis

Irisin, a novel exercise-induced myokine, has been shown to play important roles in increasing white adipose tissue browning, regulating energy metabolism and improving insulin resistance. Growing evidence suggests a direct role for irisin in preventing atherosclerosis (AS) by inhibiting oxidative stress, improving dyslipidemia, facilitating anti-inflammation, reducing cellular damage and recovering endothelial function. In addition, some studies have noted that serum irisin levels play an essential role in cardiovascular diseases (CVDs) risk prediction, highlighting that irisin has the potential to be a useful predictive marker and therapeutic target of AS, especially in monitoring therapeutic efficacy. This review summarizes the understanding of irisin-mediated regulation in essential biological pathways and functions in atherosclerosis and prompts further exploitation of the biological properties of irisin in the pathogenesis of atherosclerosis.

Abnormal TPM2 expression is involved in regulation of atherosclerosis progression via mediating RhoA signaling in vitro

Introduction

Ox-LDL (oxidized low-density lipoprotein)-induced endothelial cell injury and dysfunction of vascular smooth muscle cells play critical roles in the development of atherosclerosis (AS). Tropomyosin 2 (TPM2) has been implicated in cardiac diseases, but its critical role and regulatory mechanism in AS progression have not yet been elucidated.

Material and methods

The expression of TPM2 was investigated in AS tissues. Ox-LDL was used to construct an AS in vitro model based on endothelial and vascular smooth muscle cells (HAECs and VSMCs). An overexpression assay was performed to evaluate the role of TPM2 in AS. Meanwhile, the involvement of the RhoA pathway in TPM2-mediated AS progression was evaluated using narciclasine.

Results

Tropomyosin 2 was dramatically upregulated in both AS tissues and ox-LDL-induced HAECs. Overexpression of TPM2 attenuated ox-LDL-stimulated cell growth depression, inflammatory and adhesive responses in HAECs, as well as oxidative stress and mitochondrial dysfunction. Additionally, VSMCs, impacted by TPM2-overexpressed HAECs, showed alleviated cellular processes which were abnormally activated by ox-LDL. Furthermore, depressed activation of the RhoA pathway was found in TPM2-overexpressed HAECs and activating the signaling rescued these effects of TPM2 exerted on ox-LDL-stimulated HAECs and VSMCs.

Conclusions

TPM2 had an advantageous impact on ox-LDL-induced AS progression in vitro by mediating the RhoA pathway. This evidence might contribute to the therapy of AS.

Atherosclerosis: Conventional intake of cardiovascular drugs versus delivery using nanotechnology - A new chance for causative therapy?

Atherosclerosis is the leading cause of death in developed countries. The pathogenetic mechanism relies on a macrophage-based immune reaction to low density lipoprotein (LDL) deposition in blood vessels with dysfunctional endothelia. Thus, atherosclerosis is defined as a chronic inflammatory disease. A plethora of cardiovascular drugs have been developed and are on the market, but the major shortcoming of standard medications is that they do not address the root cause of the disease. Statins and thiazolidinediones that have recently been recognized to exert specific anti-atherosclerotic effects represent a potential breakthrough on the horizon. But their whole potential cannot be realized due to insufficient availability at the pathological site and severe off-target effects. The focus of this review will be to elaborate how both groups of drugs could immensely profit from nanoparticulate carriers. This delivery principle would allow for their accumulation in target macrophages and endothelial cells of the atherosclerotic plaque, increasing bioavailability where it is needed most. Based on the analyzed literature we conclude design criteria for the delivery of statins and thiazolidinediones with nanoparticles for anti-atherosclerotic therapy. Nanoparticles need to be below a diameter of 100 nm to accumulate in the atherosclerotic plaque and should be fabricated using biodegradable materials. Further, the thiazolidinediones or statins must be encapsulated into the particle core, because especially for thiazolidindiones the uptake into cells is prerequisite for their mechanism of action. For optimal uptake into targeted macrophages and endothelial cells, the ideal particle should present ligands on its surface which bind specifically to scavenger receptors. The impact of statins on the lectin-type oxidized LDL receptor 1 (LOX1) seems particularly promising because of its outstanding role in the inflammatory process. Using this pioneering concept, it will be possible to promote the impact of statins and thiazolidinediones on macrophages and endothelial cells and significantly enhance their anti-atherosclerotic therapeutic potential.

Resveratrol mitigates pancreatic TF activation and autophagy-mediated beta cell death via inhibition of CXCL16/ox-LDL pathway: A novel protective mechanism against type 1 diabetes mellitus in mice

The role of CXC chemokine ligand 16 (CXCL16), oxidized LDL (ox-LDL), tissue factor (TF) and autophagy-induced beta cell death in type 1 diabetes mellitus (T1DM) pathogenesis is still unclear. We examined the therapeutic potential and mechanism of resveratrol (RES) against T1DM. Diabetes was induced in Balb/c mice by i. p. injection of 55 mg/kg streptozotocin (STZ) for five consecutive days. The control group received vehicles. RES or (RES + STZ) groups received RES (50 mg/kg, i. p.) daily for 12 days starting from the fourth day of buffer or STZ injections, respectively. Blood glucose, serum insulin, beta cell mass, serum lipid profiles, histological changes, oxidative stress biomarkers were determined. Moreover, CXCL16, TF, ox-LDL, P62 and LC3 tissue expression were also analyzed. Diabetic mice showed a marked deterioration in biochemical, physical and oxidative stress parameters. Interestingly, immunofluorescence analysis showed a remarkable elevation in CXCL16 (12 folds), ox-LDL (9 folds), TF (8.3 folds) in pancreatic B-cells. Moreover, western blotting revealed a profound increase in ox-LDL (2.6 folds), TF (3.2 folds), while a significant decline in P62 (0.34) and LC3 (0.25) when compared to control. RES mitigated biochemical, physical, oxidative imbalance and distorted pancreatic architecture in T1DM mice. Intriguingly, CXCL16, ox-LDL, TF and autophagic markers were also restored after RES treatment. Our data give the first direct evidence that beta cell-specific CXCL16/ox-LDL pathway activation is a potential trigger of TF activation and autophagic beta cell death in T1DM. Moreover, RES may have potential therapeutic applications for prevention of T1DM mainly via ameliorating this pathway.

High-cholesterol diet during pregnancy induces maternal vascular dysfunction in mice: potential role for oxidized LDL-induced LOX-1 and AT1 receptor activation

The lectin-like oxidized low-density-lipoprotein (oxLDL) receptor-1 (LOX-1) has been shown to induce angiotensin II (AngII) type 1 receptor (AT1) activation, contributing to vascular dysfunction. Preeclampsia is a pregnancy complication characterized by vascular dysfunction and increased LOX-1 and AT1 activation; however, whether LOX-1 and AT1 activity contributes to vascular dysfunction in preeclampsia is unknown. We hypothesized that increased oxLDL levels during pregnancy lead to LOX-1 activation and subsequent AT1 activation, resulting in vascular dysfunction. Pregnant wild-type (WT) and transgenic LOX-1 overexpressing (LOX-1tg) mice were fed a control diet (CD) or high-cholesterol diet (HCD, to impair vascular function) between gestational day (GD) 13.5-GD18.5. On GD18.5, AngII-induced vasoconstriction and methylcholine (MCh)-induced endothelium-dependent vasodilation responses were assessed in aortas and uterine arteries. HCD decreased fetal weight and increased circulating oxLDL/cholesterol levels in WT, but not in LOX-1tg mice. HCD did not alter AngII responsiveness or AT1 expression in both vascular beds; however, AngII responsiveness and AT1 expression were lower in aortas from LOX-1tg compared with WT mice. In aortas from WT-CD mice, acute oxLDL exposure induced AT1-mediated vasoconstriction via LOX-1. HCD impaired endothelium-dependent vasodilation and increased superoxide levels in WT aortas, but not uterine arteries. Moreover, in WT-CD mice oxLDL decreased MCh sensitivity in both vascular beds, partially via LOX-1. In summary, HCD impaired pregnancy outcomes and vascular function, and oxLDL-induced LOX-1 activation may contribute to vascular dysfunction via AT1. Our study suggests that LOX-1 could be a potential target to prevent adverse outcomes associated with vascular dysfunction in preeclampsia.

The pathological growth of the prostate gland in atherogenic contexts

The human prostate is an androgen-dependent gland where an imbalance in cell proliferation can lead to benign prostatic hyperplasia (BPH), which results in voiding lower urinary tract symptoms in the elderly. In the last decades, novel evidence has suggested that BPH might represent an element into the wide spectrum of disorders conforming the Metabolic Syndrome (MS). The dyslipidemic state and the other atherogenic factors of the MS have been shown to induce, maintain and/or aggravate the pathological growth of different organs, with data regarding the prostate being still limited. We here review the available epidemiological and experimental studies about the association of BPH with dyslipidemias. In particular, we have focused on Oxidized Low-Density Lipoproteins (OxLDL) as a potential trigger for vascular disease and cellular proliferation in atherogenic contexts, analyzing their putative molecular mechanisms, including the induction of specific extracellular vesicles (EVs)-derived miRNAs. In addition to the epidemiological evidence, OxLDL is proposed to play a fundamental role in the upregulation of prostatic cell proliferation by activating the Rho/Akt/p27^Kip1 pathway in atherogenic contexts. miR-21, miR-141, miR-143, miR-145, miR-155, and miR-221 would be involved in the transcription of genes related to the proliferative process. Although much remains to be investigated regarding the impact of OxLDL, its receptors, and molecular mechanisms on the prostate, it is clear that EVs and miRNAs represent a promising target for proliferative pathologies of the prostate gland.

Postpartum microvascular functional alterations following severe preeclampsia

Preeclampsia is associated with adverse maternal health outcomes later in life. Vascular endothelial dysfunction has been previously described following preeclampsia. We hypothesized that microvascular endothelial dysfunction associated with preeclampsia persists postpartum and may identify those at greatest risk of future cardiovascular disease. The objective of this study was to examine postpartum microvascular endothelial function in women after a pregnancy complicated by preeclampsia. Women with previous preeclampsia (n = 30) and normotensive controls (n = 30) between 6 mo and 5 yr postpartum were recruited. Severity of preeclampsia [severe (n = 16) and mild (n = 14)] was determined by standardized chart review. Microvascular reactivity in the forearm was measured with laser speckle contrast imaging, coupled with iontophoresis; endothelium-dependent and endothelium-independent vasodilation was induced with 1% acetylcholine and sodium nitroprusside solutions, respectively. A postocclusive reactive hyperemia test assessed vasodilatory response following three minutes of suprasystolic (200 mmHg) occlusion with a mechanized cuff. Women with prior severe preeclampsia exhibited significantly higher vasodilation to acetylcholine and sodium nitroprusside compared to controls (P < 0.01; P = 0.03) and prior mild preeclampsia (P = 0.03; P < 0.01). Neither the degree of postocclusive reactive hyperemia (P = 0.98), nor time to return halfway to baseline [OR = 1.026 (0.612, 1.72); P = 0.92], differed between preeclampsia and controls. In conclusion, severe preeclampsia is associated with heightened postpartum microvascular endothelium-dependent and endothelium-independent vasoreactivity. These changes, or a common antecedent, may be linked to postpartum alterations in vascular function that predispose women to disease after preeclampsia. Further investigation should identify the contributing mechanism and the degree to which it could be amenable to medical intervention.NEW & NOTEWORTHY We examine maternal microvascular function after preeclampsia, identifying heightened endothelium-dependent and endothelium-independent microvascular reactivity following severe disease. Our study represents a noteworthy addition to the existing literature with the use of a novel imaging modality, vascular perturbation, postpartum time point, and patient population with differentiation of preeclampsia into severe and nonsevere subtypes. These results represent a novel addition to the growing clinical and academic understanding of maternal health outcomes following preeclampsia.

Atherogenic diet-diminished endothelial glycocalyx contributes to impaired vasomotor properties in rat

Hypercholesterolemia- and atherosclerosis-caused vasomotor property dysfunction may be involved in many clinic manifestations of atherosclerosis, including angina, acute myocardial infarction, and sudden cardiac death. However, its underlying mechanism is not clear. The endothelial glycocalyx is a protective surface layer on the endothelial cells, serving as a molecular sieve, cell adhesion modulator, and mechanosensor for blood flow. In the present study, we demonstrated by confocal microscopy in Sprague-Dawley (SD) male rats fed a 12-wk high-cholesterol diet (HC) compared with the normal diet (NC) that the dimension of the endothelial glycocalyx reduced significantly in both the common carotid artery (2.89 ± 0.41 µm and 3.25 ± 0.44 μm, respectively) and the internal sinus region (2.35 ± 0.07 µm and 3.46 ± 0.86 μm, respectively). Furthermore, we showed by real-time PCR that this dimension modification of endothelial glycocalyx may be attributed to a significant downregulation of heparan sulfate proteoglycan (HSPG)-related genes, including syndecan-3, glypican-1, and EXT1, not resulting from an enhanced shedding of sulfated glycosaminoglycans (sGAGs) from the vessel wall to the plasma. Meanwhile, the mean contraction and relaxation forces of the common carotid artery with responses to norepinephrine (NE) and acetylcholine (ACh) decreased ~0.34- and 0.13-fold, respectively, accompanied by a lower level of nitric oxide (NO) release. These findings suggest that the atherogenic high cholesterol diet diminished endothelial glycocalyx and disturbed the local NO release, thus contributing to the impaired vasomotor properties of the vessel.NEW & NOTEWORTHY Twelve-week high-cholesterol (HC) diet reduces the thickness of the endothelial glycocalyx in Sprague-Dawley (SD) male rats, which is mainly attributed to a downregulation of heparan sulfate proteoglycan-related genes (syndecan-3, glypican-1, EXT1), not resulting from an enhanced shedding of sulfated glycosaminoglycans (sGAGs) into the plasma. HC-diminished glycocalyx may disturb its mechanotransduction of local shear stress, lower nitric oxide (NO) release, and impair vasomotor responses to norepinephrine (NE) and acetylcholine (ACh).

Oxidative stress in elderly population: A prevention screening study

Background

Aging is a multifactorial phenomenon, characterized by a progressive decline in the efficiency of biochemical and physiological processes and an increased susceptibility to disease. There is increasing evidence that aging and age‐related disease are correlated with an oxidative stress (OS) condition. The latter is characterized by an imbalance between reactive species (RS), in particular reactive oxygen species (ROS) and antioxidant reserve.

Objectives

The aim of this study is to evaluate the two main markers of oxidative stress, plasmatic peroxide concentration (through d‐ROMs FAST test, derivates‐Reactive Oxygen Metabolites) and plasmatic antioxidant power measured by iron‐reducing power (PAT test, Plasma Antioxidant Test) in 290 apparently healthy volunteers over 60, and their possible correlation with age and gender.

Materials and methods

Human capillary blood samples from healthy volunteers were used in this observational study for the evaluation of the markers of OS.

Results

The data obtained broadly demonstrate that the majority of elderly people display an OS condition characterized by increased levels of peroxides and a slight reduction in antioxidant reserve.

Conclusions

Seniors have a greater propensity to develop a condition of oxidative stress, and therefore it is important to associate the monitoring of oxidative stress markers and, if necessary, antioxidant supplementation, with a healthy lifestyle.

Atherosclerosis-associated endothelial cell apoptosis by miRNA let7-b-mediated downregulation of HAS-2

MicroRNAs (miRNAs) play essential roles in the regulation and pathophysiology of various types of human diseases including atherosclerosis. Increasing numbers of miRNAs have been identified to be important regulators in the progression of atherosclerosis by regulating gene expression. However, functional miRNAs and the underlying mechanisms involved in atherosclerosis need fully elucidation. In the present study, the function of miRNA let-7b was investigated in human aortic endothelial cells (HAECs). The results showed that downregulation of let-7b in the high-fat diet mice and HAECs was inversely correlated with the expression level of HAS-2. upregulation of let-7b significantly reduced apoptosis of HAECs. The results also revealed that HAS-2 was a target gene of let-7b and HAS-2 reduction reversed the antiapoptotic effect of let-7b through regulation of the P13K/Akt pathway. These results together suggest the potential of regulating the let-7b expression and endothelial apoptosis against development and progression of atherosclerosis.

Improvement of Endothelial Dysfunction of Berberine in Atherosclerotic Mice and Mechanism Exploring through TMT-Based Proteomics

Atherosclerosis is a multifactorial vascular disease triggered by disordered lipid metabolism, characterized by chronic inflammatory injury, and initiated by endothelial dysfunction. Berberine is the main active alkaloid of the herbal medicine Coptidis Rhizoma (Huanglian). Notably, berberine has been shown to have beneficial effects against atherosclerosis. However, the mechanisms of berberine in preventing atherosclerosis are still unclear. This study is aimed at investigating the effects and mechanisms of berberine in protecting the aorta and ameliorating atherosclerosis in apolipoprotein E-deficient (ApoE^−/−) mice. Here, we demonstrated that berberine reduced serum lipid levels, antagonized hepatic lipid accumulation, improved intima-media thickening, and alleviated atherosclerotic lesions in ApoE^−/− mice fed a western-type diet for 12 weeks. Meanwhile, berberine reduced aortic reactive oxygen species (ROS) generation and reduced the serum levels of malondialdehyde (MDA), oxidized low-density lipoprotein (ox-LDL), and interleukin-6 (IL-6). In aortic ring assay, berberine restored aortic endothelium-dependent vasodilatation in vivo and in vitro. Furthermore, 4,956 proteins were identified by proteomic analysis, and 199 differentially expressed proteins regulated by berberine were found to be involved in many biological pathways, such as mitochondrial dysfunction, fatty acid β-oxidation I, and FXR/RXR activation. Summarily, these data suggested that berberine ameliorates endothelial dysfunction and protects against atherosclerosis, and thus may be a promising therapeutic candidate for atherosclerosis.

miR-101-3p induces vascular endothelial cell dysfunction by targeting tet methylcytosine dioxygenase 2

Endothelial cell (EC) dysfunction represents an early key event in atherosclerosis. Recently, MicroRNAs have been demonstrated to regulate EC function. miR-101-3p has been discovered to regulate cell apoptosis and proliferation in cardiovascular diseases. Therefore, the aim of the current study was to clarify whether miR-101-3p regulates the dysfunction of vascular endothelial cells. In this study, the transfection of human umbilical vein endothelial cells (HUVECs) with miR-101-3p mimic induced reactive oxygen species (ROS) production, EC dysfunction, and activated nuclear factor-κB (NF-κB), whereas transfection with miR-101-3p inhibitor alleviated these events. The antioxidant N-acetylcysteine alleviated miR-101-3p-induced EC dysfunction. Moreover, we observed that miR-101-3p inhibited the expression of tet methylcytosine dioxygenase 2 (TET2) at the posttranscriptional level, resulting in increased ROS production and activated NF-κB. TET2 overexpression inhibited ROS production, EC dysfunction, and NF-κB activation in miR-101-3p-transfected HUVECs. These results indicate that miR-101-3p induces EC dysfunction by targeting TET2, which regulates ROS production, EC dysfunction, and NF-κB activation. Taken together, our current study reveals a novel pathway associated with EC dysfunction. The modulation of miR-101-3p and TET2 expression levels may serve as a potential target for therapeutic strategies for atherosclerosis.

Heparin-binding epidermal growth factor (EGF)-like growth factor in pediatric patients with type 1 diabetes mellitus

Heparin-binding EGF-like growth factor (HB-EGF) is involved in atherosclerosis progression. We investigated association between plasma HB-EGF levels and lipid, oxidative stress and inflammatory biomarkers in pediatric patients with type 1 diabetes mellitus (T1DM). Levels of HB-EGF, high-sensitive C-reactive protein (hsCRP), prooxidant-antioxidant balance (PAB), total antioxidant status (TAS), oxidized low-density lipoproteins (oxLDL), metabolic control and serum lipid parameters and paraoxonase 1 (PON1) activity were determined in 74 patients and 40 controls. In comparison to controls, patients had significantly higher levels (p < 0.01) of HB-EGF, hsCRP, PAB and oxLDL particles (p < 0.001), but lower levels of TAS and PON1 activity. In T1DM group, HB-EFG levels were positively associated with hsCRP, PAB and oxLDL levels. hsCRP and oxLDL levels were independent predictors of HB-EGF concentration. We demonstrated that oxidative modifications of LDL particles and low-grade inflammation are main determinants of increased plasma HB-EGF levels, which indicates an interactive role of oxidative stress, dyslipidemia and inflammation.

Natural flavone tricetin suppresses oxidized LDL-induced endothelial inflammation mediated by Egr-1

Atherosclerosis is the primary cause of many cardiovascular diseases. Endothelial dysfunction is recognized as a crucial early event in atherosclerotic lesion formation. Tricetin is a natural flavonoid derivative that has demonstrated a wide range of therapeutic properties. This study investigates the protective effect of tricetin in cultured endothelial cells. The results of our study show that tricetin suppressed oxidized low-density lipoprotein (ox-LDL)-induced expression of pro-inflammatory monocyte chemotactic protein-1 (MCP-1) and interleukin-1β (IL-1β), as well as the generation of reactive oxygen species (ROS). Furthermore, our findings indicate that tricetin suppressed ox-LDL-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). At the cellular level, the presence of tricetin inhibited ox-LDL-induced monocyte adhesion to endothelial cells. Mechanistically, we showed that tricetin suppressed the induction of the endothelial receptor for ox-LDL, lectin-like ox-LDL receptor-1 (LOX-1), and the transcriptional factor early growth response 1 (Egr-1) as well as extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) activation. These data demonstrate that tricetin is a natural protective agent in vascular endothelial cells, indicating that tricetin could have a potentially beneficial effect in the modulation of atherosclerosis.

Effect of atherosclerosis and the protective effect of the antioxidant vitamin E on the rabbit cerebellum

BACKGROUND

Atherosclerosis is a major cardiovascular disease and one of the commonest causes of mortality in the world. Speech, balance, fine motor control and cognition are affected by atherosclerosis of cerebellar arteries. This study investigated the protective role of vitamin E against induced atherosclerosis in the rabbit cerebellum.

MATERIALS AND METHODS

Forty Rex New Zealand adult male rabbits were randomly divided into four groups (10 rabbits each). Group I was designated as the control and received an ordinary diet. Group II received an ordinary diet, but with vitamin E (12 mg/kg/day) added. Group III were given an ordinary diet along with 1% cholesterol powder for 6 weeks. Finally, group IV received an ordinary diet with both 1% cholesterol powder and vitamin E (12 mg/kg/day). Cerebellum samples were stained with haematoxylin and eosin and examined using light microscopy, along with quantitative immunohistochemical assessments of the expression of caspase-3, glial fibrillary acidic protein (GFAP) and inducible nitric oxide synthase (iNOS).

RESULTS

Cerebellum sections from cholesterol-treated rabbits showed ischaemic changes as fibre density decreased, with vacuolation of the molecular layer, and deformed and shrunken Purkinje cells. A significant increase in caspase-3, GFAP and iNOS immunoreactivity was found. However, vitamin E administration reduced these ischaemic manifestations.

CONCLUSIONS

The results demonstrate the neurological protective role of vitamin E therapy in atherosclerosis.

ATP6V0d2 controls Leishmania parasitophorous vacuole biogenesis via cholesterol homeostasis

V-ATPases are part of the membrane components of pathogen-containing vacuoles, although their function in intracellular infection remains elusive. In addition to organelle acidification, V-ATPases are alternatively implicated in membrane fusion and anti-inflammatory functions controlled by ATP6V0d2, the d subunit variant of the V-ATPase complex. Therefore, we evaluated the role of ATP6V0d2 in the biogenesis of pathogen-containing vacuoles using ATP6V0d2 knock-down macrophages infected with the protozoan parasite Leishmania amazonensis. These parasites survive within IFNγ/LPS-activated inflammatory macrophages, multiplying in large/fusogenic parasitophorous vacuoles (PVs) and inducing ATP6V0d2 upregulation. ATP6V0d2 knock-down decreased macrophage cholesterol levels and inhibited PV enlargement without interfering with parasite multiplication. However, parasites required ATP6V0d2 to resist the influx of oxidized low-density lipoprotein (ox-LDL)-derived cholesterol, which restored PV enlargement in ATP6V0d2 knock-down macrophages by replenishing macrophage cholesterol pools. Thus, we reveal parasite-mediated subversion of host V-ATPase function toward cholesterol retention, which is required for establishing an inflammation-resistant intracellular parasite niche.

Matrine attenuates high-fat diet-induced in vivo and ox-LDL-induced in vitro vascular injury by regulating the PKCα/eNOS and PI3K/Akt/eNOS pathways

Lipid metabolism disorders lead to vascular endothelial injury. Matrine is an alkaloid that has been used to improve obesity and diabetes and for the treatment of hepatitis B. However, its effect on lipid metabolism disorders and vascular injury is unclear. Here, we investigated the effect of matrine on high‐fat diet fed mice and oxidized low‐density lipoprotein (ox‐LDL)‐induced human umbilical vein endothelial cells (HUVECs). Computational virtual docking analyses, phosphoinositide 3‐kinase (PI3K) and protein kinase C‐α (PKCα) inhibitors were used to localize matrine in vascular injuries. The results showed that matrine‐treated mice were more resistant to abnormal lipid metabolism and inflammation than vehicle‐treated mice and exhibited significantly alleviated ox‐LDL‐stimulated dysfunction of HUVECs, restored diminished nitric oxide release, decreased reactive oxygen species generation and increased expression phosphorylation of AKT‐Ser473 and endothelial nitric oxide synthase (eNOS)‐Ser1177. Matrine not only up‐regulates eNOS‐Ser1177 but also down‐regulates eNOS‐Thr495, a PKCα‐controlled negative regulator of eNOS. Using computational virtual docking analyses and biochemical assays, matrine was also shown to influence eNOS/NO via PKCα inhibition. Moreover, the protective effects of matrine were significantly abolished by the simultaneous application of PKCα and the PI3K inhibitor. Matrine may thus be potentially employed as a novel therapeutic strategy against high‐fat diet‐induced vascular injury.

Galectin-3 exacerbates ox-LDL-mediated endothelial injury by inducing inflammation via integrin β1-RhoA-JNK signaling activation

Oxidized low‐density lipoprotein (Ox‐LDL)‐induced endothelial cell injury plays a crucial role in the pathogenesis of atherosclerosis (AS). Plasma galectin‐3 (Gal‐3) is elevated inside and drives diverse systemic inflammatory disorders, including cardiovascular diseases. However, the exact role of Gal‐3 in ox‐LDL‐mediated endothelial injury remains unclear. This study explores the effects of Gal‐3 on ox‐LDL‐induced endothelial dysfunction and the underlying molecular mechanisms. In this study, Gal‐3, integrin β1, and GTP‐RhoA in the blood and plaques of AS patients were examined by ELISA and western blot respectively. Their levels were found to be obviously upregulated compared with non‐AS control group. CCK8 assay and flow cytometry analysis showed that Gal‐3 significantly decreased cell viability and promoted apoptosis in ox‐LDL‐treated human umbilical vascular endothelial cells (HUVECs). The upregulation of integrinβ1, GTP‐RhoA, p‐JNK, p‐p65, p‐IKKα, and p‐IKKβ induced by ox‐LDL was further enhanced by treatment with Gal‐3. Pretreatment with Gal‐3 increased expression of inflammatory factors (interleukin [IL]‐6, IL‐8, and IL‐1β), chemokines(CXCL‐1 and CCL‐2) and adhesion molecules (VCAM‐1 and ICAM‐1). Furthermore, the promotional effects of Gal‐3 on NF‐κB activation and inflammatory factors in ox‐LDL‐treated HUVECs were reversed by the treatments with integrinβ1‐siRNA or the JNK inhibitor. We also found that integrinβ1‐siRNA decreased the protein expression of GTP‐RhoA and p‐JNK, while RhoA inhibitor partially reduced the upregulated expression of p‐JNK induced by Gal‐3. In conclusion, our finding suggests that Gal‐3 exacerbates ox‐LDL‐mediated endothelial injury by inducing inflammation via integrin β1‐RhoA‐JNK signaling activation.

Resveratrol exhibits an effect on attenuating retina inflammatory condition and damage of diabetic retinopathy via PON1

Diabetic retinopathy (DR), an obstacle of the visual microvascular system, is a serious complication of diabetic patients. Paraoxonase 1 (PON1) has been extensively evaluated as a genetic candidate for diabetic microvascular complications, and PON1 is associated with DR. In this study, the biological functions of PON1 and its related proteins were determined via gene ontology (GO) enrichment analysis; we demonstrated that treatment with resveratrol alleviated retinal inflammatory activities to evaluate its protective effects on streptozotocin (STZ)-induced diabetic rats and high-glucose (HG) stimulated rat retinal endothelial cells (RRECs). The GO enrichment analysis suggested that PON1 may regulate inflammatory responses and microvascular complications in DR. In an in vivo study, resveratrol significantly recovered the insulin level and PON1 expression and activity, as well as clearly reduced the retinal vascular permeability, retinal AGEs, LDL, Ox-LDL, caspase3 activity, retinal damage, IL-1β, IL-6, TNFα, VEGF, IFNγ and MCP-1 in STZ-diabetic rats. Moreover, resveratrol reduced the caspase3 activity and Ox-LDL expression in HG stimulated RRECs. However, its protective effect was a deficiency in PON1-silenced RRECs. PON1 is a pivotal modulator in the role of resveratrol in reversing the RREC damage induced by HG. Furthermore, we found that resveratrol exhibits an effect on attenuating the retinal inflammatory condition and damage of DR via PON1. Our study suggests that resveratrol-induced PON1 in the retina may be a promising therapeutic strategy to prevent diabetes-related retinopathy.

Biochemical and histological evidence of deteriorated bioprosthetic valve leaflets: the accumulation of fibrinogen and plasminogen

Calcification of bioprosthetic valves (BVs) implanted in aortic position can result in gradual deterioration and necessitate aortic valve replacement. The molecular mechanism of calcium deposition on BV leaflets has been investigated, but remains to be fully elucidated. The present study aimed to identify explanted bioprosthetic valve (eBV)-specific proteins using a proteomics approach and to unveil their biochemical and histological involvements in calcium deposition on BV leaflets. Calcification, fibrosis, and glycosylation of the valves were histologically assessed using Von Kossa, Masson's Trichrome and Alcian Blue staining, as well as immunostaining. Protein expression in the explanted biological valves was analysed using proteomics and western blotting. In a histological evaluation, αSMA-positive myofibroblasts were not observed in eBV, whereas severe fibrosis occurred around calcified areas. SDS-PAGE revealed three major bands with considerably increased intensity in BV leaflets that were identified as plasminogen and fibrinogen gamma chain (100 kDa), and fibrinogen beta chain (50 and 37 kDa) by mass analysis. Immunohistochemistry showed that fibrinogen β-chain was distributed throughout the valve tissue. On the contrary, plasminogen was strongly stained in CD68-positive macrophages, as evidenced by immunofluorescence. The results suggest that two important blood coagulation-related proteins, plasminogen and fibrinogen, might affect the progression of BV degeneration.

Summary: Fibrinogen was specifically deposited on whole deteriorated tissue valve leaflets, and plasminogen-positive macrophages strongly invaded the areas around calcified bioprosthetic and native tissues.

Circulating low density lipoprotein (LDL)

Low-density lipoprotein (LDL) particles are known as atherogenic agents in coronary artery diseases. They modify to other electronegative forms and may be the subject for improvement of inflammatory events in vessel subendothelial spaces. The circulating LDL value is associated with the plasma PCSK-9 level. They internalize into macrophages using the lysosomal receptor-mediated pathways. LDL uptake is related to the membrane scavenger receptors, modifications of lipid and protein components of LDL particles, vesicular maturation and lipid stores of cells. Furthermore, LDL vesicular trafficking is involved with the function of some proteins such as Rab and Lamp families. These proteins also help in the transportation of free cholesterol from lysosome into the cytosol. The aggregation of lipids in the cytosol is a starting point for the formation of foam cells so that they may participate in the primary core of atherosclerosis plaques. The effects of macrophage subclasses are different in the formation and remodeling of plaques. This review is focused on the cellular and molecular events involved in cholesterol homeostasis.

Depletion of haptoglobin and hemopexin promote hemoglobin-mediated lipoprotein oxidation in sickle cell disease

Intravascular sickling and lysis of red blood cells, a hallmark feature of sickle cell disease (SCD), releases hemoglobin (Hb) into the circulation. Increased cell-free Hb has been linked to vasculopathy and in vitro lipid oxidation. Scavenger plasma proteins haptoglobin (Hp) and hemopexin (Hpx) can attenuate cell-free Hb and total plasma heme lipid-oxidative capacity but are depleted in SCD. Here, we isolated lipids from BERK-SS mice, guinea pigs (GP) infused with heme-albumin, and patients with SCD undergoing regular exchange transfusion therapy and evaluated the level of lipid oxidation. Malondialdehyde formation, an end product of lipid peroxidation, was increased in BERK-SS mice, purified lipid fractions of the heme-albumin infused GP, and patients with SCD compared with controls. In humans, the extent of lipid oxidation was associated with the absence of Hp as well as decreased Hpx in plasma samples. Postmortem pulmonary tissue obtained from patients with SCD demonstrated oxidized LDL deposition in the pulmonary artery. The relationship between no Hp and low Hpx levels with greater LDL and HDL oxidation demonstrates the loss of protection against cell-free Hb and total plasma heme-mediated lipid oxidation and tissue injury in SCD. Strategies to protect against plasma lipid oxidation by cell-free Hb and total plasma heme (e.g., therapeutic Hp and Hpx replacement) may diminish the deleterious effects of cell-free Hb and total plasma heme toward the vascular system in SCD.

The Effects of Selenium Supplementation on Gene Expression Related to Insulin and Lipid in Infertile Polycystic Ovary Syndrome Women Candidate for In Vitro Fertilization: a Randomized, Double-Blind, Placebo-Controlled Trial

This study was conducted to evaluate the effects of selenium supplementation on gene expression related to insulin and lipid in infertile women with polycystic ovary syndrome (PCOS) candidate for in vitro fertilization (IVF). This randomized double-blind, placebo-controlled trial was conducted among 40 infertile women with PCOS candidate for IVF. Subjects were randomly allocated into two groups to intake either 200-μg selenium (n = 20) or placebo (n = 20) per day for 8 weeks. Gene expression levels related to insulin and lipid were quantified in lymphocytes of women with PCOS candidate for IVF with RT-PCR method. Results of RT-PCR demonstrated that after the 8-week intervention, compared with the placebo, selenium supplementation upregulated gene expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) (1.06 ± 0.15-fold increase vs. 0.94 ± 0.18-fold reduction, P = 0.02) and glucose transporter 1 (GLUT-1) (1.07 ± 0.20-fold increase vs. 0.87 ± 0.18-fold reduction, P = 0.003) in lymphocytes of women with PCOS candidate for IVF. In addition, compared with the placebo, selenium supplementation downregulated gene expression of low-density lipoprotein receptor (LDLR) (0.88 ± 0.17-fold reduction vs. 1.05 ± 0.22-fold increase, P = 0.01) in lymphocytes of women with PCOS candidate for IVF. We did not observe any significant effect of selenium supplementation on gene expression levels of lipoprotein(a) [LP(a)] in lymphocytes of women with PCOS candidate for IVF. Overall, selenium supplementation for 8 weeks in lymphocytes of women with infertile PCOS candidate for IVF significantly increased gene expression levels of PPAR-γ and GLUT-1 and significantly decreased gene expression levels of LDLR, but did not affect LP(a).

CLINICAL TRIAL REGISTRATION NUMBER

http://www.irct.ir : IRCT201704245623N113.

The protease inhibitor E64d improves ox-LDL-induced endothelial dysfunction in human aortic endothelial cells

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction in human vascular endothelial cells contributes to the development of atherosclerosis. E64d, a cysteine protease inhibitor, blocks the elastolytic activity of cathepsin essential for vascular matrix remodeling and reduces neurovascular endothelial apoptosis. The objective of this study was to investigate the effects and the underling mechanisms of E64d on ox-LDL-induced endothelial dysfunction in human aortic endothelial cells (HAECs). HAECs were treated with various concentrations of ox-LDL (0–200 mg/L) for 24 h with or without E64d. The results showed that E64d attenuated ox-LDL-induced increase in soluble intercellular adhesion molecule-1 (sICAM-1) concentration and reduction in endothelial nitric oxide synthase (eNOS) expression, prevented ox-LDL-induced reduction in cell viability and migration ability of HAECs. E64d decreased the protein expression of cathepsin B (CTSB), Beclin 1, and microtubule-associated protein light chain 3 (LC3)-II, but not p62. LC3 puncta and autophagosome formation were also reduced by E64d in HAECs. Moreover, E64d decreased the production of MDA and increased the activity of SOD. The results showed that E64d ameliorated ox-LDL-induced endothelial dysfunction in HAECs.

Oxidative Phospholipidomics in health and disease: Achievements, challenges and hopes

Phospholipid peroxidation products are recognized as important bioactive lipid mediators playing an active role as modulators in signalling events in inflammation, immunity and infection. The biochemical responses are determined by the oxidation structural features present in oxPL modulating biophysical and biological properties in model membranes and lipoproteins. In spite of the extensive work conducted with model systems over the last 20 years, the study of oxPL in biological systems has virtually stagnated. In fact, very little is known concerning the predominant oxPL in fluids and tissues, their basal levels, and any variations introduced with age, gender and ethnicity in health and disease. In consequence, knowledge on oxPL has not yet translated into clinical diagnostic, in the early and timely diagnosis of "silent" diseases such as atherosclerosis and cardiovascular diseases, or as prognosis tools in disease stratification and particularly useful in the context of multimorbidities. Their use as therapeutic solutions or the development of innovative functional biomaterials remains to be explored. This review summarizes the achievements made in the identification of oxPL revealing an enormous structural diversity. A brief overview of the challenges associated with the analysis of such diverse array of products is given and a critical evaluation on key aspects in the analysis pipeline that need to be addressed. Once these issues are addressed, Oxidative Phospholipidomics will hopefully lead to major breakthrough discoveries in biochemistry, pharmaceutical, and clinical areas for the upcoming 20 years. This article is part of Special Issue entitled 4-Hydroxynonenal and Related Lipid Oxidation Products.

Lipids on the Second Day in Ischemic and Normoxemic Term Neonates

INTRODUCTION

In hypoxic newborns requiring oxygen, lipid peroxidation affects the peripheral blood lipids.

OBJECTIVES

Determine the influence of perinatal oxygen therapy for hypoxia on serum lipid concentrations on the second day of life.

MATERIALS AND METHODS

Our study included 50 newborns with perinatal hypoxia requiring oxygen and 50 healthy newborns without oxygen therapy. Arterialized capillary blood was taken for categorization of hypoxia (pO2) after birth in both groups. Lipid concentrations: total cholesterol (TC), high density lipoproteins (HDL), low density lipoproteins (LDL), and triglycerides (TG) were measured on day 2 in both groups.

RESULTS

TC, LDL, HDL, TG, HC03 levels were statistically lower in the study group compared to the control one, while pCO2 and BE levels were statistically higher in newborns with perinatal hypoxia.

CONCLUSION

Lower lipid levels in hypoxic newborns may suggest that circulating lipids are oxidized, peroxidized, and removed from the peripheral circulation.

Serum oxidized low-density lipoprotein levels are related to cardiometabolic risk and decreased after a weight loss treatment in obese children and adolescents

BACKGROUND AND AIMS

The oxidation of low-density lipoprotein (LDL) cholesterol particles is an early atherogeninic event. Obese pediatric populations have higher levels of oxidized LDL (oxLDL) than normal weight children. The aim of this study was to evaluate the effect of a weight loss program on the biochemical profile and oxLDL levels in Spanish obese children and adolescents.

METHODS

Forty obese children (mean age 11 years, 51% boys) followed a 10-week weight loss program. They were dichotomized at the median of body mass index-standard deviation score (BMI-SDS) change, as high (HR) and low responders (LR) after the intervention. The intervention included a moderate energy-restricted diet, nutritional education, and family involvement. Anthropometric and biochemical measurements were performed at the beginning and during the follow up. A cardiometabolic risk score (CMS) was calculated considering metabolic risk factors.

RESULTS

Higher baseline oxLDL levels were associated with a higher CMS in obese children (P < .001). After the intervention, oxLDL significantly decreased in the HR group. Moreover, a positive correlation between changes in oxLDL and BMI-SDS (r = 0.385, P = .015) was found after the weight loss program. Interestingly, multiple-adjusted regression models showed an association between changes in total cholesterol [B: 0.127, 95% confidence interval (CI): 0.06 to 0.20] and LDL-cholesterol (B: 0.173, 95% CI: 0.08 to 0.26) with changes in oxLDL.

CONCLUSIONS

Higher baseline oxLDL levels were associated with a higher CMS in obese children. After the weight loss program, a decrease in oxLDL levels was found in HR subjects and the oxLDL levels were associated with BMI-SDS and cholesterol levels.

Selenium modulates MMP2 expression through the TGFβ1/Smad signalling pathway in human umbilical vein endothelial cells and rabbits following lipid disturbance

BACKGROUND

A high-fat diet is a major risk factor for coronary heart diseases. Matrix metalloprotease (MMP) expression is changed in many cardiovascular diseases. Selenium, which is an important trace element in animals, has a close relationship with cardiovascular diseases. The TGFβ1/Smad signalling pathway is ubiquitous in diverse tissues and cells, and it is also associated with the occurrence and development of cardiovascular diseases. Therefore, in this study, we aimed to determine selenium's effect on lipid metabolism, atherosclerotic plaque formation, and MMP2 expression, as well as the underlying functional mechanism.

METHODS AND RESULTS

In vivo tests: 24 male New Zealand white rabbits were randomly divided into 4 groups: regular diet, high-fat diet, high-fat diet+selenium and regular diet+selenium groups. The high-fat diet induced the lipid disturbances of rabbits at week 12. Selenium supplementation lowered total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels (p<0.01). Selenium supplementation also suppressed MMP2 over-expression in thoracic aortas. In vitro tests: Human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of selenium or ox-LDL. Ox-LDL promoted MMP2 expression by increasing TGFβ1, pSmad2, pSmad3 and Smad3 expression (p<0.01). Selenium attenuated MMP2 over-expression by regulating the TGFβ1/Smad signalling pathway.

CONCLUSIONS

Selenium suppressed high-fat diet-induced MMP2 over-expression in vivo by improving lipid metabolism. In vitro, selenium attenuated MMP2 over-expression through the TGFβ1/Smad signalling pathway.

DC-SIGN and Toll-like receptor 4 mediate oxidized low-density lipoprotein-induced inflammatory responses in macrophages

The regulation of inflammatory responses by innate immune receptors is recognized as a crucial step in the development of atherosclerosis, although the precise molecular mechanisms remain to be elucidated. This study focused on illustrating the roles of dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN)- and Toll-like receptor 4 (TLR4)-regulated inflammatory responses in macrophages. We found that DC-SIGN expression levels were increased in macrophages of atherosclerotic plaques. Oxidized low-density lipoprotein (oxLDL) significantly enhanced DC-SIGN protein expression levels after a short-term exposure. Knockdown of DC-SIGN decreased expression and secretion of interleukin 1-β (IL1-β), monocyte chemo-attractant protein 1 (MCP-1), tumor necrosis factor-α (TNFα) and matrix metalloproteinase-9 (MMP-9). Immunofluorescence studies demonstrated that DC-SIGN and TLR4 co-localized in regions of the plaques. Moreover, DC-SIGN was co-expressed with TLR4 on the plasma membrane after oxLDL stimulation. The presence of an endogenous interaction and the results of the in vitro pull-down assays revealed that DC-SIGN binds directly with TLR4. We also present evidence that DC-SIGN mediates TLR4-regulated NFκB activation but not activation of p38 and JNK. Our results suggest an essential role of DC-SIGN/TLR4 signaling in macrophages in the pathogenesis of atherosclerosis.

Vitamin K2 can suppress the expression of Toll-like receptor 2 (TLR2) and TLR4, and inhibit calcification of aortic intima in ApoE-/- mice as well as smooth muscle cells

Background and objectives Vascular calcification is a common complication in atherosclerosis. Accumulating evidence showed that Toll-like receptors (TLRs) mediate pro-inflammatory and atherosclerosis. Recent studies demonstrated that vascular calcification is one of the detrimental effects of vitamin K (Vit K) antagonists. However, the effects of Vit K on the expression of TLR2 and 4 and intimal calcification in artery remained unidentified. Methods and results Eighteen ApoE^-/- mice were randomly divided into model group, Vit K-treated group, and control group. The mice of model and Vit K-treated group were fed with high-fat diet, while control group mice were fed with normal diet. Mice of Vit K-treated group were administered orally with vitamin K2 (40 mg.kg^-1.day^-1) for 12 weeks. Twelve weeks later the aortic sections of mice were acquired and stained with hematoxylin and eosin and von Kossa, respectively. Calcium content and activity of alkaline phosphatase (ALP) at aortic tissues were measured. The expression levels of TLR2 and TLR4 in aorta sections were detected by immunohistochemisty and RT-PCR, respectively. The effects of Vit K on cellular calcification were further studied in A7r5 SMCs. Results demonstrated that high-fat diet induced typical atherosclerosis with intimal calcification in ApoE^-/- mice, while in Vit K-treated group atherosclerosis and calcium deposits were not serious; Vit K2 also inhibited cellular calcification in A7r5 SMCs. Quantitative analysis showed that calcium and ALP activity at aortic tissues in the Vit K-treated mice were significantly lower than that of the model group ( P < 0.01); Compared to the control group, the expression levels of TLR2 and TLR4 in the model group were significantly higher ( P < 0.05), while in Vit K-treated group the levels of TLR2 and 4 were significantly lower than that in the model group. Furthermore, the content of calcium was positively related to the expression levels of TLR2 and TLR4 mRNA at aortic tissues ( r = 0.77 and r = 0.79, respectively, both P < 0.001). Conclusion VitK2 can inhibit intimal calcification of aortic artery induced by high-fat diet in ApoE^-/- mice and A7r5 SMCs calcification induced by β-sodium glycerophosphate, and meanwhile can reduce the expression of TLR2 and TLR4. These results suggested that the effects of VitK2 on vascular calcification may be associated with the expression of TLR2 and TLR4.

Combined Effects of Curcumin and Lycopene or Bixin in Yoghurt on Inhibition of LDL Oxidation and Increases in HDL and Paraoxonase Levels in Streptozotocin-Diabetic Rats

Combination therapy using natural antioxidants to manage diabetes mellitus and its complications is an emerging trend. The aim of this study was to investigate the changes promoted by treatment of streptozotocin (STZ)-diabetic rats with yoghurt enriched with the bioactives curcumin, lycopene, or bixin (the latter two being carotenoids). Antioxidants were administered individually, or as mixtures, and biomarkers of metabolic and oxidative disturbances, particularly those associated with cardiovascular risk, were assessed. Treatment of STZ-diabetic rats with natural products individually decreased glycemia, triacylglycerol, total-cholesterol, oxidative stress biomarkers, including oxidized low-density lipoprotein (ox-LDL), and increased the activities of antioxidant enzymes. Individual carotenoids increased both high-density lipoprotein (HDL) and paraoxonase levels, whereas curcumin increased only paraoxonase. Treatments with mixtures of curcumin and lycopene or bixin had combined effects, decreasing biomarkers of carbohydrate and lipid disturbances (curcumin effect), increasing the HDL levels (carotenoids effects) and mitigating oxidative stress (curcumin and carotenoids effects). The combined effects also led to prevention of the LDL oxidation, thereby mitigating the cardiovascular risk in diabetes. These findings provide evidence for the beneficial effect of curcumin and carotenoid mixtures as a supplementation having antioxidant and antiatherogenic potentials, thus appearing as an interesting strategy to be studied as a complementary therapy for diabetic complications.

Endothelial long non-coding RNAs regulated by oxidized LDL

Oxidized low-density lipoprotein (oxLDL) plays a central role in the pathogenesis of atherosclerosis, in part via an effect to promote endothelial dysfunction. In the present study, we evaluated the expression profiles of long non-coding RNAs (lncRNAs) and protein-coding mRNAs in endothelial cells following oxLDL stimulation. LncRNAs and mRNAs from human umbilical vein endothelial cells (HUVECs) were profiled with the Arraystar Human lncRNA Expression Microarray V3.0 following 24 h of oxLDL treatment (100 µg/mL). Of the 30,584 lncRNAs screened, 923 were significantly up-regulated and 975 significantly down-regulated (P < 0.05) in response to oxLDL exposure. In the same HUVEC samples, 518 of the 26,106 mRNAs screened were up-regulated and 572 were down-regulated. Of these differentially expressed lncRNAs, CLDN10-AS1 and CTC-459I6.1 were the most up-regulated (~87-fold) and down-regulated (~28-fold), respectively. Bioinformatic assignment of the differentially regulated genes into functional groups indicated that many are involved in signaling pathways among which are the cytokine receptor, chemokine, TNF, MAPK and Ras signaling pathways, olfactory transduction, and vascular smooth muscle cell function. This is the first report profiling oxLDL-mediated changes in lncRNA and mRNA expression in human endothelial cells. The novel targets revealed substantially extend the list of potential candidate genes involved in atherogenesis.

MicroRNA-98 rescues proliferation and alleviates ox-LDL-induced apoptosis in HUVECs by targeting LOX-1

Oxidized low-density lipoprotein (ox-LDL) is a major and critical mediator of atherosclerosis, and the underlying mechanism is thought to involve the ox-LDL-induced dysfunction of endothelial cells (ECs). MicroRNAs (miRNAs), which are a group of small non-coding RNA molecules that post-transcriptionally regulate the expression of target genes, have been associated with diverse cellular functions and the pathogenesis of various diseases, including atherosclerosis. miRNA-98 (miR-98) has been demonstrated to be involved in the regulation of cellular apoptosis; however, the role of miR-98 in ox-LDL-induced dysfunction of ECs and atherosclerosis has yet to be elucidated. Therefore, the present study aimed to investigate the role of miR-98 in ox-LDL-induced dysfunction of ECs and the underlying mechanism. It was demonstrated that miR-98 expression was markedly downregulated in ox-LDL-treated human umbilical vein ECs (HUVECs) and that miR-98 promoted the proliferation and alleviated apoptosis of HUVECs exposed to ox-LDL. In addition, the results demonstrated that lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1) was a direct target of miR-98 in HUVECs, as indicated by a luciferase assay. The results of the present study suggested that miR-98 may inhibit the uptake of toxic ox-LDL, maintain HUVEC proliferation and protect HUVECs against apoptosis via the suppression of LOX-1.

Interleukin-37 suppresses the osteogenic responses of human aortic valve interstitial cells in vitro and alleviates valve lesions in mice

Calcific aortic valve disease is a chronic inflammatory process, and aortic valve interstitial cells (AVICs) from diseased aortic valves express greater levels of osteogenic factors in response to proinflammatory stimulation. Here, we report that lower cellular levels of IL-37 in AVICs of diseased human aortic valves likely account for augmented expression of bone morphogenetic protein-2 (BMP-2) and alkaline phosphatase (ALP) following stimulation of Toll-like receptor (TLR) 2 or 4. Treatment of diseased AVICs with recombinant human IL-37 suppresses the levels of BMP-2 and ALP as well as calcium deposit formation. In mice, aortic valve thickening is observed when exposed to a TLR4 agonist or a high fat diet for a prolonged period; however, mice expressing human IL-37 exhibit significantly lower BMP-2 levels and less aortic valve thickening when subjected to the same regimens. A high fat diet in mice results in oxidized low-density lipoprotein (oxLDL) deposition in aortic valve leaflets. Moreover, the osteogenic responses in human AVICs induced by oxLDL are suppressed by recombinant IL-37. Mechanistically, reduced osteogenic responses to oxLDL in human AVICs are associated with the ability of IL-37 to inhibit NF-κB and ERK1/2. These findings suggest that augmented expression of osteogenic factors in AVICs of diseased aortic valves from humans is at least partly due to a relative IL-37 deficiency. Because recombinant IL-37 suppresses the osteogenic responses in human AVICs and alleviates aortic valve lesions in mice exposed to high fat diet or a proinflammatory stimulus, IL-37 has therapeutic potential for progressive calcific aortic valve disease.

Elevating CXCR7 Improves Angiogenic Function of EPCs via Akt/GSK-3β/Fyn-Mediated Nrf2 Activation in Diabetic Limb Ischemia

RATIONALE

Endothelial progenitor cells (EPCs) respond to stromal cell-derived factor 1 (SDF-1) through chemokine receptors CXCR7 and CXCR4. Whether SDF-1 receptors involves in diabetes mellitus-induced EPCs dysfunction remains unknown.

OBJECTIVE

To determine the role of SDF-1 receptors in diabetic EPCs dysfunction.

METHODS AND RESULTS

CXCR7 expression, but not CXCR4 was reduced in EPCs from db/db mice, which coincided with impaired tube formation. Knockdown of CXCR7 impaired tube formation of EPCs from normal mice, whereas upregulation of CXCR7 rescued angiogenic function of EPCs from db/db mice. In normal EPCs treated with oxidized low-density lipoprotein or high glucose also reduced CXCR7 expression, impaired tube formation, and increased oxidative stress and apoptosis. The damaging effects of oxidized low-density lipoprotein or high glucose were markedly reduced by SDF-1 pretreatment in EPCs transduced with CXCR7 lentivirus but not in EPCs transduced with control lentivirus. Most importantly, EPCs transduced with CXCR7 lentivirus were superior to EPCs transduced with control lentivirus for therapy of ischemic limbs in db/db mice. Mechanistic studies demonstrated that oxidized low-density lipoprotein or high glucose inhibited protein kinase B and glycogen synthase kinase-3β phosphorylation, nuclear export of Fyn and nuclear localization of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), blunting Nrf2 downstream target genes heme oxygenase-1, NAD(P)H dehydrogenase (quinone 1) and catalase, and inducing an increase in EPC oxidative stress. This destructive cascade was blocked by SDF-1 treatment in EPCs transduced with CXCR7 lentivirus. Furthermore, inhibition of phosphatidylinositol 3-kinase/protein kinase B prevented SDF-1/CXCR7-mediated Nrf2 activation and blocked angiogenic repair. Moreover, Nrf2 knockdown almost completely abolished the protective effects of SDF-1/CXCR7 on EPC function in vitro and in vivo.

CONCLUSIONS

Elevated expression of CXCR7 enhances EPC resistance to diabetes mellitus-induced oxidative damage and improves therapeutic efficacy of EPCs in treating diabetic limb ischemia. The benefits of CXCR7 are mediated predominantly by a protein kinase B/glycogen synthase kinase-3β/Fyn pathway via increased activity of Nrf2.

MicroRNA-210 induces endothelial cell apoptosis by directly targeting PDK1 in the setting of atherosclerosis

Background

Atherosclerosis is a chronically inflammatory disease and one of the leading causes of deaths worldwide. Endothelial cell apoptosis plays a crucial role in its development. Several microRNAs (miRNAs) are reportedly involved in atherosclerotic plaque formation, including miRNA-210 (miR-210). However, the underlying mechanism of its role in endothelial cell apoptosis during atherosclerosis is still largely unknown.

Methods

A mouse model with atherosclerosis induced by a high-fat diet (HFD) was built in ApoE (-/-) mice. The levels of endothelial cell apoptosis were determined via flow cytometry. The expressions of miR-210 and PDK1 in purified CD31+ endothelial cells from mouse aorta were measured via RT-qPCR and western blot. Binding between miR-210 and the 3′-untranslated region (UTR) of PDK1 mRNA was predicted using bioinformatics analyses and confirmed with a dual luciferase reporter assay. The effects of miR-210 were further analyzed in an in vitro model using human aortic endothelial cells (HAECs) treated with oxidized low-density lipoprotein (ox-LDL).

Results

We found that the HFD mice developed atherosclerosis in 12 weeks and had a significantly higher percentage of endothelial cell apoptosis. The upregulated level of miR-210 in the HFD mice and HAECs inversely correlated with the level of PDK1. Inhibiting miR-210 expression significantly reduced HAEC apoptosis, as evidenced by the results of the MTT and flow cytometry experiments. Further analysis identified PDK1 as the target of miR-210 and showed that PDK1 overexpression reversed the pro-apoptotic effect of miR-210 through mediation of the P13K/Akt/mTOR pathways.

Conclusion

Our study suggests a novel role for miR-210 in the progression of atherosclerosis through the regulation of endothelial apoptosis. This indicates that miR-210 might have potential in treatment of atherosclerosis.

Comparison of lipid profile parameters and oxidized low-density lipoprotein between normal and preeclamptic pregnancies in a tertiary care hospital in Nepal

Introduction

Preeclampsia is a pregnancy-specific complication that significantly contributes to maternal and perinatal morbidity and mortality worldwide, even more so in developing countries such as Nepal. The potential contribution of dyslipidemia and elevated levels of oxidized low-density lipoprotein (oxLDL) in the pathogenesis of preeclamptic pregnancies has been observed in several studies. The aim of this study was to compare the maternal lipid profile parameters and particularly oxLDL between preeclamptic and healthy pregnancies and also correlate oxLDL with other lipid profile parameters.

Patients and methods

A total of 54 preeclamptic women were selected as cases for this cross-sectional study. Age and gestational week-matched 60 pregnant women were enrolled as controls. Preeclampsia was defined as per Australasian Society Consensus Statement research definition. The serum lipid parameters were measured using automated enzymatic systems and a competitive enzyme-linked immunosorbent assay was used to determine oxLDL concentrations in the serum. Student’s t-test was used to compare oxLDL levels between preeclamptic and healthy pregnancies, and Pearson’s correlation analysis was carried out to assess the relation between oxLDL and other variables.

Results

The mean values of serum total cholesterol, triglyceride, non-high-density lipoprotein-cholesterol (non-HDL-c) and oxLDL were significantly higher in the preeclamptic cases (P<0.01). However, the levels of low-density lipoprotein cholesterol (LDL-c and HDL-c) did not significantly differ between the two groups. oxLDL had a significant positive correlation (P<0.01) with total cholesterol, triglyceride, LDL-c and non-HDL-c, and a negative correlation with HDL-c.

Conclusion

The atherogenic type of dyslipidemia and high oxLDL levels are associated with preeclamptic pregnancies. The lipid parameters, however, seem to be poor markers of the severity of preeclampsia. Further prospective studies are needed to see if the observed dyslipidemia has a causal role in preeclampsia and imparts a long-term cardiovascular risk.