LOX-1 is a novel marker for peripheral artery disease in patients with type 2 diabetes

Role of exosome-derived miRNAs in diabetic wound angiogenesis

Chronic wounds with high disability are among the most common and serious complications of diabetes. Angiogenesis dysfunction impair wound healing in patients with diabetes. Compared with traditional therapies that can only provide symptomatic treatment, stem cells-owing to their powerful paracrine properties, can alleviate the pathogenesis of chronic diabetic wounds and even cure them. Exosome-derived microRNAs (miRNAs), important components of stem cell paracrine signaling, have been reported for therapeutic use in various disease models, including diabetic wounds. Exosome-derived miRNAs have been widely reported to be involved in regulating vascular function and have promising applications in the repair and regeneration of skin wounds. Therefore, this article aims to review the current status of the pathophysiology of exosome-derived miRNAs in the diabetes-induced impairment of wound healing, along with current knowledge of the underlying mechanisms, emphasizing the regulatory mechanism of angiogenesis, we hope to document the emerging theoretical basis for improving wound repair by restoring angiogenesis in diabetes.

Serum Soluble Lectin-like Oxidized Low-Density Lipoprotein Receptor-1 (sLOX-1) Is Associated with Atherosclerosis Severity in Coronary Artery Disease

Risk-factor-based scoring systems for atherosclerotic coronary artery disease (CAD) remain concerningly inaccurate at the level of the individual and would benefit from the addition of biomarkers that correlate with atherosclerosis burden directly. We hypothesized that serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) would be independently associated with CAD and investigated this in the BioHEART study using 968 participants with CT coronary angiograms, which were scored for disease burden in the form of coronary artery calcium scores (CACS), Gensini scores, and a semi-quantitative soft-plaque score (SPS). Serum sLOX-1 was assessed by ELISA and was incorporated into regression models for disease severity and incidence. We demonstrate that sLOX-1 is associated with an improvement in the prediction of CAD severity when scored by Gensini or SPS, but not CACS. sLOX-1 also significantly improved the prediction of the incidence of obstructive CAD, defined as stenosis in any vessel >75%. The predictive value of sLOX-1 was significantly greater in the subgroup of patients who did not have any of the standard modifiable cardiovascular risk factors (SMuRFs). sLOX-1 is associated with CAD severity and is the first biomarker shown to have utility for risk prediction in the SMuRFless population.

Associations of Tissue and Soluble LOX-1 with Human Abdominal Aortic Aneurysm

Background Indication for prophylactic surgical abdominal aortic aneurysm (AAA) repair depends on the maximal aortic diameter. The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is the major receptor for uptake of oxidized low-density lipoprotein cholesterol and is implicated in atherosclerosis. A soluble form of LOX-1 (sLOX-1) has been discussed as a novel biomarker in coronary artery disease and stroke. Herein, we assessed the regulation of aortic LOX-1 as well as the diagnostic and risk stratification potential of sLOX-1 in patients with AAA. Methods and Results Serum sLOX-1 was assessed in a case-control study in AAA (n=104) and peripheral artery disease (n=104). sLOX-1 was not statistically different between AAA and peripheral artery disease but was higher in AAA (β=1.28, P=0.04) after adjusting for age, atherosclerosis, type 2 diabetes, prescription of statins, β-blockers, ACE inhibitors, and therapeutic anticoagulation. sLOX-1 was not associated with the aortic diameter, AAA volume, or the thickness of the intraluminal thrombus. Aortic LOX-1 mRNA expression tended to be higher in AAA when compared with disease, and expression was positively associated with cleaved caspase-3, smooth muscle actin, collagen, and macrophage content. Conclusions In AAA, sLOX-1 was differently affected by age, cardiometabolic diseases, and corresponding medical therapies. Comparison with nonatherosclerotic disease would be beneficial to further elucidate the diagnostic potential of sLOX-1, although it was not useful for risk stratification. Aneurysmal LOX-1 mRNA expression was increased and positively associated with smooth muscle cells and collagen content, suggesting that LOX-1 is eventually not deleterious in human AAA and could counteract AAA rupture.

Effects of Tofogliflozin and Anagliptin Alone or in Combination on Glucose Metabolism and Atherosclerosis-Related Markers in Patients with Type 2 Diabetes Mellitus

Purpose

In people with type 2 diabetes mellitus (T2DM), both glucose metabolism abnormalities and atherosclerosis risk are significant concerns. This study aims to investigate the effects of the sodium-glucose cotransporter 2 inhibitor tofogliflozin (TOFO) and the dipeptidyl peptidase-4 inhibitor anagliptin (ANA) on markers of glucose metabolism and atherosclerosis when administered individually or in combination.

Methods

Fifty T2DM patients were divided into two groups (receiving either TOFO or ANA monotherapy) and observed for 12 weeks (observation points: 0 and 12 weeks). The TOFO and ANA groups were then further treated with ANA and TOFO, respectively, and the patients were observed for an additional 36 weeks (observation points: 24 and 48 weeks). Therapeutic effects and various biomarkers were compared between the two groups at the observation points.

Results

Combination therapy led to significant improvements in HbA1c levels and atherosclerosis markers. Additionally, the TOFO pretreatment group exhibited significant reductions in sLOX-1 and IL-6 levels.

Conclusion

The increase in sLOX-1 and IL-6 levels, which indicates the response of scavenger receptors to oxidized low-density lipoproteins in people with T2DM, is mitigated following TOFO and ANA combination therapy. TOFO alone or in combination with ANA may be beneficial for preventing atherosclerosis development in people with T2DM, in addition to its effect on improving HbA1c levels.

Association of Lower Extremity Vascular Disease, Coronary Artery, and Carotid Artery Atherosclerosis in Patients with Type 2 Diabetes Mellitus

The motive of this article is to present the case study of patients to investigate the association between the ultrasonographic findings of lower extremity vascular disease (LEAD) and plaque formation. Secondly, to examine the association between the formation of coronary artery and carotid artery atherosclerosis in patients with type 2 diabetes mellitus. 124 patients with type 2 diabetes (64 males and 60 females with the age group 25-78 years) are considered for the research studies who have registered themselves in the Department of Endocrinology and Metabolism from April 2017 to February 2019. All participants have reported their clinical information regarding diabetes, alcohol consumption, smoking status, and medication. The blood samples from subjects are collected for measurement of HbA_1c, total cholesterol, triglycerides, HDL-c, and LDL-c levels. Two-dimensional ultrasound has been used to measure the inner diameter, peak flow velocity, blood flow, and spectral width of the femoral artery, pop artery, anterior iliac artery, posterior tibial artery, and dorsal artery and to calculate the artery stenosis degree. Independent factors of atherosclerosis are determined by multivariate logistic regression analysis. The results are evaluated within the control group and it is found that there is no significant impact of gender, age, and body mass index (P > 0.05) on the lower extremity vascular diseases. Those with smoking, alcohol consumption, hypertension, and dyslipidemia have higher positive rate (P < 0.05). The type 2 diabetes mellitus group has higher diastolic blood pressure and lower triglyceride (P < 0.05). Diastolic blood pressure, HbA_1C, total cholesterol, HDL-c, and LDL-C are not remarkably dissimilar between the type 2 diabetes mellitus group and the control group (P > 0.05). Compared with the control group, the type 2 diabetes mellitus group has higher frequency of lower extremity vascular diseases in the dorsal artery than in the pop artery (P < 0.05). The blood flow of type 2 diabetes mellitus group is found to be lower than that of the control group, especially in the dorsal artery (P < 0.05). The blood flow velocity of the dorsal artery is accelerated (P < 0.01). Among 117 patients of type 2 diabetes mellitus (94.35%) with a certain degree of injury, there are 72 cases of type I carotid stenosis (58.06%), 30 cases of type II carotid stenosis (24.19%), and 15 cases of type III carotid stenosis (12.10%). Out of 108 subjects in the control group, there are 84 cases of type 0 carotid stenosis (77.78%), 19 cases of type I carotid stenosis (17.59%), 5 cases of type II carotid stenosis (4.63%), and 0 case of type III carotid stenosis (0.00%). Compared with the control group, carotid stenosis is more common in patients with type 2 diabetes mellitus (P < 0.05). Age, smoking, duration of diseases, systolic blood pressure, and degree of carotid stenosis are found to be associated with atherosclerosis. The findings suggest that the color Doppler ultrasonography can give early warning when applied in patients with carotid and lower extremity vascular diseases to delay the incidence of diabetic macroangiopathy and to control the development of cerebral infarction, thus providing an important basis for clinical diagnosis and treatment.

Association of circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 with inflammatory markers and urinary albumin excretion in patients with type 2 diabetes

OBJECTIVES

The main purpose of the study was to study the association between circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 levels and various markers, including inflammatory markers such as high-sensitivity C-reactive protein and fibrinogen, serum lipids, and renal function, in patients with poorly controlled type 2 diabetes.

METHODS

The subjects were 70 patients (men 45, women 25) who were hospitalized for treatment of poor glycemic control. Plasma soluble lectin-like oxidized low-density lipoprotein receptor-1 levels were assayed using a sandwich chemiluminescence enzyme immunoassay.

RESULTS

Circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 was significantly positively correlated with lectin-like oxidized low-density lipoprotein-1 ligands containing apolipoprotein B, reflecting modified low-density lipoprotein, and with inflammatory markers such as high-sensitivity C-reactive protein and fibrinogen. In addition, there was a significant positive correlation between soluble lectin-like oxidized low-density lipoprotein receptor-1 and urinary albumin excretion.

CONCLUSIONS

Soluble lectin-like oxidized low-density lipoprotein receptor-1 may serve as a marker reflecting the degrees of inflammation and albuminuria in patients with poorly controlled type 2 diabetes.

Lower extremity artery disease in patients with type 2 diabetes

Among all peripheral arterial diseases, lower extremity arterial disease is a serious condition in subjects with type 2 diabetes mellitus, associated with important disability, cardiovascular risk, and socio-economic burden. Patients with both conditions generally display poorer prognosis of affected limbs compared with non-diabetic subjects, leading to increased rates of adverse limb events including amputations. Nonetheless, awareness on lower extremity arterial disease remains somehow suboptimal in the diabetic population, partly related to an atypical clinical presentation in several cases. A regular and appropriate screening for lower extremity arterial disease in patients suffering from type 2 diabetes mellitus is therefore recommended. Affected subjects should receive optimal medical treatment including careful management of the different cardiovascular risk factors through a healthy lifestyle, a regular and structured physical activity, the administration of lipid-lowering, antidiabetic drugs, and (when indicated) antihypertensive and antithrombotic drugs. This review aims to outline current evidence about lower extremity arterial disease in patients with type 2 diabetes mellitus, in order to elucidate its epidemiology, pathophysiology, screening and diagnosis, and management options.

The association between local arteriosclerosis of the prostatic arteries and chronic inflammation in human benign prostatic enlargement

BACKGROUND

To elucidate the pathogenesis of benign prostatic enlargement (BPE) in humans due to chronic inflammation caused by arteriosclerosis, the relationships between prostate size and the degree of chronic inflammation induced by local arteriosclerosis were investigated.

METHODS

The present cohort included 50 subjects who underwent robot-assisted radical prostatectomy (RARP) in a prospective study. The presence or absence of local arteriosclerosis in the prostatic arteries removed during RARP was evaluated by microscopic assessment. Chronic inflammation in the prostate was judged according to both the density and the extent of inflammatory cells. The expression of lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and the infiltration of macrophages in the prostate, which are high in arteriosclerosis, were investigated by immunohistochemistry.

RESULTS

Local arteriosclerosis was observed in 28% (14/50). Prostate size and the inflammation score were significantly increased in the presence of arteriosclerosis (P = 0.006, P < 0.001, respectively). There was also a significant increase of LOX-1 in the epithelial and stromal cells of the prostate in the presence of arteriosclerosis (all, P < 0.001). Concerning the presence of macrophages, subjects with arteriosclerosis had significantly more positive expression of ionized calcium-binding adapter molecule-1 (IBA-1), a marker of macrophages, than subjects without arteriosclerosis (P < 0.001).

CONCLUSIONS

In human surgical specimens, chronic inflammation owing to local arteriosclerosis of the prostatic arteries was significantly related to prostatic enlargement. Given the immunohistochemical analyses, the putative pathogenesis for this relationship is that LOX-1 induces macrophage infiltration, leading to BPE.

LOX-1 and atherosclerotic-related diseases

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), a scavenger receptor of oxidized low-density lipoprotein (ox-LDL) found in various cells, plays a crucial role in the formation and progression of atherosclerotic plaques. Animal studies have suggested that LOX-1 mediates the balance between internalization and degeneration of endothelial cells, thereby contributing to various steps in the atherosclerotic process, from initiation to plaque rupture. Under pathological conditions, the extracellular domain of membrane bound LOX-1 can be largely proteolytically cleaved into a soluble form (sLOX-1), which is proportional and linked to the LOX-1 expression level. Circulating levels of sLOX-1 are regarded as a risk biomarker for plaque rupture and acute coronary syndrome (ACS). Recently, studies have shown that sLOX-1 is also elevated in patients with acute stroke and can be a predictive biomarker for acute stroke. With the discovery of the vital role of LOX-1 in atherosclerosis, there is growing focus on the influence of LOX-1 in atherosclerotic-related diseases, including coronary arterial disease(CAD), stroke, and other cardiovascular events. Genetic polymorphisms of LOX-1 have been investigated and have been found to modulate the risk of these diseases. Most polymorphisms have been found to be risk factors, except for the splicing isoform LOXIN. This review concludes with a discussion of the potential future applications of LOX-1 for atherosclerotic-related diseases.

Macro- and microvascular endothelial dysfunction in diabetes

Endothelial cells, as well as their major products nitric oxide (NO) and prostacyclin, play a key role in the regulation of vascular homeostasis. Diabetes mellitus is an important risk factor for cardiovascular disease. Diabetes-induced endothelial dysfunction is a critical and initiating factor in the genesis of diabetic vascular complications. The present review focuses on both large blood vessels and the microvasculature. The endothelial dysfunction in diabetic macrovascular complications is characterized by reduced NO bioavailability, poorly compensated for by increased production of prostacyclin and/or endothelium-dependent hyperpolarizations, and increased production or action of endothelium-derived vasoconstrictors. The endothelial dysfunction of microvascular complications is primarily characterized by decreased release of NO, enhanced oxidative stress, increased production of inflammatory factors, abnormal angiogenesis, and impaired endothelial repair. In addition, non-coding RNAs (microRNAs) have emerged as participating in numerous cellular processes. Thus, this reviews pays special attention to microRNAs and their modulatory role in diabetes-induced vascular dysfunction. Some therapeutic strategies for preventing and restoring diabetic endothelial dysfunction are also highlighted.

Pathophysiology of peripheral arterial disease in diabetes mellitus

Peripheral arterial disease (PAD) increases the risk of lower extremity amputation. It is also an independent predictor of cardiovascular and cerebrovascular ischemic events, affecting both the quality and expectancy of life. Many studies have demonstrated that the prevalence of PAD in patients with diabetes mellitus (DM) is higher than in non-diabetic patients. In diabetic patients, PAD occurs early with rapid progression, and is frequently asymptomatic. Multiple metabolic aberrations in DM, such as advanced glycation end-products, low-density lipoprotein cholesterol, and abnormal oxidative stress, have been shown to worsen PAD. However, the role of DM in PAD is not completely understood. The purpose of the present article is to review and discuss the pathophysiology of PAD in DM.

Upregulation of OLR1 and IL17A genes and their association with blood glucose and lipid levels in femoropopliteal artery disease

Oxidized low-density lipoprotein receptor 1 (OLR1) and interleukin 17A (IL17A) have pro-inflammatory roles in the development of cardiovascular disorders. The present study evaluated the association of OLR1 and IL17A and their polymorphisms with the development of femoropopliteal (FP) artery disease. The mRNA expression of OLR1 and IL17A in peripheral blood mononuclear cells as well as the frequency of OLR1 rs11053646 and IL17A rs8193037 and rs3819025 polymorphisms were assessed by polymerase chain reaction in 70 patients with FP artery disease and 80 age-matched disease-free controls. Furthermore, the levels of plasma cytokines were assessed by multiplex immunoassay. OLR1 and IL17A mRNA expression was significantly higher in patients with FP artery disease compared with that in controls (P<0.001). No significant difference was observed in the genotypic frequencies of OLR1 rs11053646 (P=0.87) or in IL17A rs8193037 and rs3819025 (P=0.80 and 0.92, respectively) polymorphisms between patients with FP artery disease and controls. Plasma IL4, -6, -10, -22, -31 and -33 as well as soluble cluster of differentiation 40 ligand and tumor necrosis factor-α levels were significantly increased among FP artery disease patients compared with controls (P<0.05). Furthermore, OLR1 expression was positively correlated with triglyceride (r=0.463, P<0.001), low-density lipoprotein cholesterol (r=0.507, P<0.001) and total cholesterol levels (r=0.357, P=0.006) in patients with FP artery disease. To the best of our knowledge, the present study was the first to identify an association between OLR1 and IL17A genes and FP artery disease. OLR1 and IL17A mRNA transcripts may be associated with blood lipid parameters and with the development of FP artery disease.

Association of the LOX-1 rs1050283 Polymorphism with Risk for Atherosclerotic Cerebral Infarction and its Effect on sLOX-1 and LOX-1 Expression in a Chinese Population

AIMS

The interaction between lectin-like oxidized low density lipoprotein (LDL) receptor-1 (LOX-1) and oxidized LDL (ox-LDL) has been viewed as an important pathogenic factor for cardiovascular diseases. This study aimed to explore the association of a functional polymorphism rs1050283 in the 3'-untranslated region of the LOX-1 gene with atherosclerotic cerebral infarction (ACI) susceptibility, and we also investigated the effects of the rs1050283 polymorphism on LOX-1 expression and serum levels of sLOX-1 in patients with ACI.

METHODS

A case-controlled study was performed in 526 patients with ACI and 640 healthy controls. Genotyping was performed by DNA sequencing method. Real-time PCR and Western blotting were used to determine the level of LOX-1 expression. Serum levels of sLOX-1 were quantified using ELISA according to the manufacturer's instruction.

RESULTS

The results of the present study showed that the frequency of rs1050283 T allele was significantly higher in patients with ACI than in healthy controls. We also found that the rs1050283 polymorphism T allele was associated with increased LOX-1 expression at mRNA and protein levels in patients with ACI. Furthermore, we also observed that among patients with ACI, those with the rs1050283 T allele showed an increased serum level of sLOX-1.

CONCLUSION

Our research demonstrated that the rs1050283 T allele of LOX-1 is strongly associated with an increased risk for ACI in a Chinese population, which also affects levels of LOX-1 and sLOX-1.

Association of coronary artery calcification with liver fibrosis in Japanese patients with non-alcoholic fatty liver disease

AIMS

Cardiovascular events are the leading cause of death among patients with non-alcoholic fatty liver disease (NAFLD), but their relationship remains unclear. This study examined the association between coronary atherosclerosis and liver fibrosis, represented by the coronary artery calcification (CAC) score and non-invasive fibrosis markers, respectively.

METHODS

Among 698 patients with chest pain or electrocardiographic abnormalities who underwent coronary computed tomography (CT) between April 2006 and March 2010, those with known liver disorders or history of emergency coronary angioplasty were excluded, leaving 366 patients for this study. Diagnosis of NAFLD was based on abdominal CT and history of alcohol consumption. Subjects with CAC of 100 AU or more were categorized into the high-risk group for cardiovascular events. Patient records were examined for clinical parameters including CAC score and non-invasive fibrosis marker FIB-4 index.

RESULTS

Ninety-four patients (25.7%) had NAFLD. In this group, univariate analysis identified old age, high diastolic blood pressure, high liver to spleen ratio and high FIB-4 index as risk factors for cardiovascular events and multivariate analysis identified age of 66 years or older and FIB-4 index of 2.09 or more as the significant risk factors. For the observation period until August 2014, the cumulative proportion of PCI performance was significantly higher in patients with FIB-4 of 2.09 or more than those with FIB-4 of less than 2.09.

CONCLUSION

The progression of arteriosclerosis and that of liver fibrosis may be associated in NAFLD patients. The FIB-4 index can be easily determined and thus can be a useful marker for predicting cardiovascular events in NAFLD patients.

Effects of cigarette smoking on cardiovascular-related protein profiles in two community-based cohort studies

BACKGROUND AND AIMS

Cardiovascular diseases account for the largest fraction of smoking-induced deaths. Studies of smoking in relation to cardiovascular-related protein markers can provide novel insights into the biological effects of smoking. We investigated the associations between cigarette smoking and 80 protein markers known to be related to cardiovascular diseases in two community-based cohorts, the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS, n = 969, 50% women, all aged 70 years) and the Uppsala Longitudinal Study of Adult Men (ULSAM, n = 717, all men aged 77 years).

METHODS

Smoking status was self-reported and defined as current smoker, former smoker or never-smoker. Levels of the 80 proteins were measured using the proximity extension assay, a novel PCR-based proteomics technique.

RESULTS

We found 30 proteins to be significantly associated with current cigarette smoking in PIVUS (FDR<5%); and ten were replicated in ULSAM (p < 0.05). Matrix metalloproteinase-12 (MMP-12), growth/differentiation factor 15 (GDF-15), urokinase plasminogen activator surface receptor (uPAR), TNF-related apoptosis-inducing ligand receptor 2 (TRAIL-R2), lectin-like oxidized LDL receptor 1 (LOX-1), hepatocyte growth factor (HGF), matrix metalloproteinase-10 (MMP-10) and matrix metalloproteinase-1 (MMP-1) were positively associated, while endothelial cell-specific molecule 1 (ESM-1) and interleukin-27 subunit alpha (IL27-A) showed inverse associations. All of them remained significant in a subset of individuals without manifest cardiovascular disease.

CONCLUSIONS

The findings of the present study suggest that cigarette smoking may interfere with several essential parts of the atherosclerosis process, as evidenced by associations with protein markers representing endothelial dysfunction, inflammation, neointimal formation, foam cell formation and plaque instability.

Low CD36 and LOX-1 Levels and CD36 Gene Subexpression Are Associated with Metabolic Dysregulation in Older Individuals with Abdominal Obesity

Background. Obesity study in the context of scavenger receptors has been linked to atherosclerosis. CD36 and LOX-1 are important, since they have been associated with atherogenic and metabolic disease but not fat redistribution. The aim of our study was to determinate the association between CD36 and LOX-1 in presence of age and abdominal obesity. Methods. This is a cross-sectional study that included 151 healthy individuals, clinically and anthropometrically classified into two groups by age (<30 and ≥30 years old) and abdominal obesity (according to World Health Organization guidelines). We excluded individuals with any chronic and metabolic illness, use of medication, or smoking. Fasting blood samples were taken to perform determination of CD36 mRNA expression by real-time PCR, lipid profile and metabolic and low grade inflammation markers by routine methods, and soluble scavenger receptors (CD36 and LOX-1) by ELISA. Results. Individuals ≥30 years old with abdominal obesity presented high atherogenic index, lower soluble scavenger receptor levels, and subexpression of CD36 mRNA (54% less). On the other hand, individuals <30 years old with abdominal adiposity presented higher levels in the same parameters, except LOX-1 soluble levels. Conclusion. In this study, individuals over 30 years of age presented low soluble scavenger receptors levels pattern and CD36 gene subexpression, which suggest the chronic metabolic dysregulation in abdominal obesity.

Plasma L5 levels are elevated in ischemic stroke patients and enhance platelet aggregation

L5, the most electronegative and atherogenic subfraction of low-density lipoprotein (LDL), induces platelet activation. We hypothesized that plasma L5 levels are increased in acute ischemic stroke patients and examined whether lectin-like oxidized LDL receptor-1 (LOX-1), the receptor for L5 on endothelial cells and platelets, plays a critical role in stroke. Because amyloid β (Aβ) stimulates platelet aggregation, we studied whether L5 and Aβ function synergistically to induce prothrombotic pathways leading to stroke. Levels of plasma L5, serum Aβ, and platelet LOX-1 expression were significantly higher in acute ischemic stroke patients than in controls without metabolic syndrome (P < .01). In mice subjected to focal cerebral ischemia, L5 treatment resulted in larger infarction volumes than did phosphate-buffered saline treatment. Deficiency or neutralizing of LOX-1 reduced infarct volume up to threefold after focal cerebral ischemia in mice, illustrating the importance of LOX-1 in stroke injury. In human platelets, L5 but not L1 (the least electronegative LDL subfraction) induced Aβ release via IκB kinase 2 (IKK2). Furthermore, L5+Aβ synergistically induced glycoprotein IIb/IIIa receptor activation; phosphorylation of IKK2, IκBα, p65, and c-Jun N-terminal kinase 1; and platelet aggregation. These effects were blocked by inhibiting IKK2, LOX-1, or nuclear factor-κB (NF-κB). Injecting L5+Aβ shortened tail-bleeding time by 50% (n = 12; P < .05 vs L1-injected mice), which was prevented by the IKK2 inhibitor. Our findings suggest that, through LOX-1, atherogenic L5 potentiates Aβ-mediated platelet activation, platelet aggregation, and hemostasis via IKK2/NF-κB signaling. L5 elevation may be a risk factor for cerebral atherothrombosis, and downregulating LOX-1 and inhibiting IKK2 may be novel antithrombotic strategies.

Association between plasma sLOX-1 concentration and arterial stiffness in middle-aged and older individuals

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is implicated in vascular endothelial function. Vascular endothelial function is a potent regulator of arterial stiffness, an independent risk factor for cardiovascular disease. However, it is unknown whether LOX-1 is associated with arterial stiffness. Plasma concentrations of soluble LOX-1 (sLOX-1) and brachial-ankle pulse wave velocity (baPWV, an index of arterial stiffness) were measured in 143 individuals between 51 and 83 years of age. Plasma sLOX-1 concentration was correlated with baPWV (r = 0.288, p = 0.0005). In stepwise regression analysis, plasma sLOX-1 concentration was associated with baPWV, after adjusting for age; body mass index; blood pressure; heart rate; blood levels of cholesterol, triglycerides, glucose, hemoglobin A1c, and insulin; sex; and use of antihypertensives, lipid-lowering agents, and other medications (R² = 0.575, p<0.0001). Multiple logistic regression demonstrated that plasma sLOX-1 concentration was independently associated with elevated baPWV (≥14.0 m/s; odds ratio, 1.01; 95% confidence interval, 1.00–1.03; p = 0.03). These results suggest that LOX-1 is associated with arterial stiffness.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), soluble lectin-like oxidized LDL receptor 1 (sLOX-1) and ankle brachial index in patients with differentiated thyroid cancer

The cardiovascular effects of short-term overt hypothyroidism are not well known. We investigated proprotein convertase subtilisin/kexin type 9 (PCSK9), soluble lectin-like oxidized LDL receptor 1 (sLOX-1) and the ankle brachial index (ABI) in thyroid cancer patients with short-term overt hypothyroidism due to thyroid hormone withdrawal (THW). Twenty-one patients requiring radioactive iodine (RAI) ablation or scanning and 36 healthy control subjects were enrolled. Patients were evaluated in the subclinical thyrotoxic phase when they were on suppressive levothyroxine therapy and in the overt hypothyroid phase due to THW for four weeks. PCSK9, sLOX-1, lipids and ABI were measured in the patient and control groups. Total cholesterol, LDL cholesterol, triglycerides and Apo B levels were increased in short overt hypothyroidism compared with the control group (p<0.001). PCSK9 levels increased before THW and after THW in the patients compared to control group (p<0.001, p=0.004, respectively). sLOX-1 levels were not different between patients with short term overt hypothyroidism and control group (p=0.27). ABI was found to be significantly decreased in patients with thyroid cancer before and after THW compared to control group (p=0.04, p=0.002 respectively). PCSK9 levels were correlated negatively with ABI (r=-0.38, p=0.004). In conclusion; our study demonstrated that patients with differentiated thyroid cancer both before and after THW which is a short term overt hypothyroid phase, had increased PCSK9 levels and decreased ABI. Short term overt hypothyroidism also leads to increased HDL, LDL, total cholesterol, Apo A and Apo B levels.

Soluble lectin-like oxidized low density lipoprotein receptor-1 as a biochemical marker for atherosclerosis-related diseases

Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), the main oxidized low-density lipoprotein (OxLDL) in endothelial cells, is upregulated in atherosclerotic lesions and is involved in several cellular processes that regulate the pathogenesis of atherosclerosis. The LOX-1 expressed on the cell surface can be proteolytically cleaved and released in a soluble form (sLOX-1) in the circulation under pathological conditions. Serum levels of sLOX-1, in fact, are elevated at the early stages of acute coronary syndrome and are associated with coronary plaque vulnerability and with the presence of multiple complex coronary lesions. Moreover, in subjects with stable CAD, levels of serum sLOX-1 are associated with the presence of lesions in the proximal and mid-segments of the left anterior descending artery that are the most prone to rupture; in subjects undergoing percutaneous coronary intervention, baseline preprocedural serum sLOX-1 levels are associated with the incidence of periprocedural myocardial infarction. Altogether, these findings suggest that circulating levels of sLOX-1 might be a diagnostic and prognostic marker for atherosclerotic-related events.