LOX-1 in Cardiovascular Disease: A Comprehensive Molecular and Clinical Review.

LOX-1, ORL-1, or lectin-like oxidized low-density lipoprotein receptor 1 is a transmembrane glycoprotein that binds and internalizes ox-LDL in foam cells. LOX-1 is the main receptor for oxidized low-density lipoproteins (ox-LDL). The LDL comes from food intake and circulates through the bloodstream. LOX-1 belongs to scavenger receptors (SR), which are associated with various cardiovascular diseases. The most important and severe of these is the formation of atherosclerotic plaques in the intimal layer of the endothelium. These plaques can evolve into complicated thrombi with the participation of fibroblasts, activated platelets, apoptotic muscle cells, and macrophages transformed into foam cells. This process causes changes in vascular endothelial homeostasis, leading to partial or total obstruction in the lumen of blood vessels. This obstruction can result in oxygen deprivation to the heart. Recently, LOX-1 has been involved in other pathologies, such as obesity and diabetes mellitus. However, the development of atherosclerosis has been the most relevant due to its relationship with cerebrovascular accidents and heart attacks. In this review, we will summarize findings related to the physiologic and pathophysiological processes of LOX-1 to support the detection, diagnosis, and prevention of those diseases.

Kirenol protects against oxidized low-density lipoprotein induced damages in endothelial cells / Kirenol protege contra danos induzidos por lipoproteínas de baixa densidade oxidadas em células endoteliais

Kirenol (KNL) has recently been reported to have anti-inflammatory properties. Yet, little is known about the potential mechanisms of its anti-inflammatory properties. In HUVECs, we elucidated the anti-inflammatory mechanisms of kirenol. RT-PCR was used to test mRNA of pro-inflammatory mediators produced by Ox-LDL. The viability of cells was measured using MTT. Western blots analyzed protein levels. On Ox-LDL-stimulated HUVECs, KNL significantly inhibited the production of pro-inflammatory mediators such as NO, IL-1ß, iNOS, TNF-α and IL-6. p38, ROS and Nrf2 expression were inhibited by KNL. Inhibition of p38, ROS, and KNL caused nuclear accumulation of Nrf2. KNL attenuated Ox-LDL-induced phosphorylation of ERK1/2 and p38, too. Based on our results, KNL inhibits NF-кB and MAPK signaling in HUVECs by activating Nrf2 signaling. There's a possibility that KNL could be developed into an anti-inflammatory drug.

Kirenol (KNL) foi recentemente relatado como tendo propriedades anti-inflamatórias. No entanto, pouco se sabe sobre os potenciais mecanismos de suas propriedades anti-inflamatórias. Em HUVECs, elucidamos os mecanismos anti-inflamatórios do kirenol. RT-PCR foi usado para testar mRNA de mediadores pró-inflamatórios produzidos por Ox-LDL. A viabilidade das células foi medida usando MTT. Western blots analisaram os níveis de proteína. Em HUVECs estimuladas por Ox-LDL, o KNL inibiu significativamente a produção de mediadores pró-inflamatórios como NO, IL-1ß, iNOS, TNF-α e IL-6. A expressão de p38, ROS e Nrf2 foi inibida por KNL. A inibição de p38, ROS e KNL causou acúmulo nuclear de Nrf2. O KNL também atenuou a fosforilação induzida por Ox-LDL de ERK1/2 e p38. Com base em nossos resultados, o KNL inibe a sinalização de NF-кB e MAPK em HUVECs, ativando a sinalização de Nrf2. Existe a possibilidade de que o KNL possa ser desenvolvido em um medicamento anti-inflamatório.

LOX-1 Activation by oxLDL Induces AR and AR-V7 Expression via NF-κB and STAT3 Signaling Pathways Reducing Enzalutamide Cytotoxic Effects.

The oxidized low-density lipoprotein receptor 1 (LOX-1) is one of the most important receptors for modified LDLs, such as oxidated (oxLDL) and acetylated (acLDL) low-density lipoprotein. LOX-1 and oxLDL are fundamental in atherosclerosis, where oxLDL/LOX1 promotes ROS generation and NF-κB activation inducing the expression of IL-6, a STAT3 activator. Furthermore, LOX-1/oxLDL function has been associated with other diseases, such as obesity, hypertension, and cancer. In prostate cancer (CaP), LOX-1 overexpression is associated with advanced stages, and its activation by oxLDL induces an epithelial-mesenchymal transition, increasing angiogenesis and proliferation. Interestingly, enzalutamide-resistant CaP cells increase the uptake of acLDL. Enzalutamide is an androgen receptor (AR) antagonist for castration-resistant prostate cancer (CRPC) treatment, and a high percentage of patients develop a resistance to this drug. The decreased cytotoxicity is promoted in part by STAT3 and NF-κB activation that induces the secretion of the pro-inflammatory program and the expression of AR and its splicing variant AR-V7. Here, we demonstrate for the first time that oxLDL/LOX-1 increases ROS levels and activates NF-κB, inducing IL-6 secretion and the activation of STAT3 in CRPC cells. Furthermore, oxLDL/LOX1 increases AR and AR-V7 expression and decreases enzalutamide cytotoxicity in CRPC. Thus, our investigation suggests that new factors associated with cardiovascular pathologies, such as LOX-1/oxLDL, may also promote important signaling axes for the progression of CRPC and its resistance to drugs used for its treatment.

Role of CD36 in cancer progression, stemness, and targeting.

CD36 is highly expressed in diverse tumor types and its expression correlates with advanced stages, poor prognosis, and reduced survival. In cancer cells, CD36: 1) increases fatty acid uptake, reprogramming lipid metabolism; 2) favors cancer cell proliferation, and 3) promotes epithelial-mesenchymal transition. Furthermore, CD36 expression correlates with the expression of cancer stem cell markers and CD36+ cancer cells display increased stemness functional properties, including clonogenicity, chemo- and radioresistance, and metastasis-initiating capability, suggesting CD36 is a marker of the cancer stem cell population. Thus, CD36 has been pointed as a potential therapeutic target in cancer. At present, at least three different types of molecules have been developed for reducing CD36-mediated functions: blocking monoclonal antibodies, small-molecule inhibitors, and compounds that knock-down CD36 expression. Herein, we review the role of CD36 in cancer progression, its participation in stemness control, as well as the efficacy of reported CD36 inhibitors in cancer cell cultures and animal models. Overall, the evidence compiled points that CD36 is a valid target for the development of new anti-cancer therapies.

OxLDL induces membrane structure rearrangement leading to biomechanics alteration and migration deficiency in macrophage.

Cholesterol sequestration from plasma membrane has been shown to induce lipid packing disruption, causing actin cytoskeleton reorganization and polymerization, increasing cell stiffness and inducing lysosomal exocytosis in non-professional phagocytes. Similarly, oxidized form of low-density lipoprotein (oxLDL) has also been shown to disrupt lipid organization and packing in endothelial cells, leading to biomechanics alterations that interfere with membrane injury and repair. For macrophages, much is known about oxLDL effects in cell activation, cytokine production and foam cell formation. However, little is known about its impact in the organization of macrophage membrane structured domains and cellular mechanics, the focus of the present study. Treatment of bone marrow-derived macrophages (BMDM) with oxLDL not only altered membrane structure, and potentially the distribution of raft domains, but also induced actin rearrangement, diffuse integrin distribution and cell shrinkage, similarly to observed upon treatment of these cells with MßCD. Those alterations led to decreased migration efficiency. For both treatments, higher co-localization of actin cytoskeleton and GM1 was observed, indicating a similar mechanism of action involving raft-like domain dynamics. Lastly, like MßCD treatment, oxLDL also induced lysosomal spreading in BMDM. We propose that OxLDL induced re-organization of membrane/cytoskeleton complex in macrophages can be attributed to the insertion of oxysterols into the membrane, which lead to changes in lipid organization and disruption of membrane structure, similar to the effect of cholesterol depletion by MßCD treatment. These results indicate that oxLDL can induce physical alterations in the complex membrane/cytoskeleton of macrophages, leading to significant biomechanical changes that compromise cell behavior.

Changes in the plasma lipidome of healthy subjects after coffee consumption reveal potential cardiovascular benefits: A randomized controlled trial.

Lipid metabolism dysregulation is associated with cardiovascular disease (CVD) risk. Specific oxidized lipids are recognized CVD biomarkers involved in all stages of atherosclerosis, including foam cell formation. Moderate coffee intake is positively associated with cardiovascular health. A randomized, controlled (n = 25) clinical trial was conducted in healthy subjects to assess the changes in lipid species relevant to CVD (main inclusion criteria: coffee drinkers, nonsmokers, with no history and/or diagnosis of chronic disease and not consuming any medications). Volunteers consumed a coffee beverage (400 mL/day) containing either 787 mg (coffee A; n = 24) or 407 mg (coffee B; n = 25) of chlorogenic acids for eight weeks. We measured the total plasma levels of 46 lipids, including fatty acids, sterols, and oxysterols, at baseline and after eight weeks and assessed the effects of chlorogenic and phenolic acids, the major coffee antioxidants, in an in vitro foam cell model via targeted lipidomics. At baseline (n = 74), all participants presented oxysterols and free fatty acids (FFAs) (CVD risk markers), which are closely correlated to among them, but not with the classical clinical variables (lipid profile, waist circumference, and BMI). After eight weeks, the control group lipidome showed an increase in oxysterols (+7 ± 10%) and was strongly correlated with FFAs (e.g., arachidonic acid) and cholesteryl ester reduction (-13 ± 7%). Notably, the coffee group subjects (n = 49) had increased cholesteryl esters (+9 ± 11%), while oxysterols (-71 ± 30%) and FFAs (-29 ± 26%) decreased. No differences were found between the consumption of coffees A and B. Additionally, coffee antioxidants decreased oxysterols and regulated arachidonic acid in foam cells. Our results suggest that coffee consumption modulates the generation of oxidized and inflammatory lipids in healthy subjects, which are fundamental during CVD development. The clinical trial was registered on the International Clinical Trials Registry Platform, WHO primary registry (RPCEC00000168).

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/p27Kip1 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.

miR-92a-3p promotes ox-LDL induced-apoptosis in HUVECs via targeting SIRT6 and activating MAPK signaling pathway

Atherosclerosis could be induced by multiple factors, including hypertension, hyperlipidemia, and smoking, and its pathogenesis has not been fully elucidated. MicroRNAs have been shown to possess great anti-atherosclerotic potential, but the precise function of miR-92a-3p in atherosclerosis and its potential molecular mechanism have not been well clarified. Flow cytometry assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT) assay were performed to evaluate effects of oxidized low-density lipoprotein (ox-LDL) on proliferation and apoptosis of human umbilical vein endothelial cells (HUVECs), respectively. Malondialdehyde and superoxide dismutase levels in cell lysate were assessed with biochemical kits. The expression levels of miR-92a-3p and Sirtuin6 (SIRT6) in HUVECs exposed to ox-LDL were estimated by real-time quantitative polymerase chain reaction (RT-qPCR). In addition, the protein levels of SIRT6, c-Jun N-terminal kinase (JNK), phosphorylation JNK (p-JNK), p38 mitogen activated protein kinase (p38 MAPK), and phosphorylation p38 MAPK (p-p38 MAPK) were measured by western blot assays. The relationship between miR-92a-3p and SIRT6 was confirmed by dual-luciferase reporter assay. Ox-LDL induced apoptosis and oxidative stress in HUVECs in concentration- and time-dependent manners. Conversely, miR-92a-3p silencing inhibited apoptosis and SIRT6 expression in HUVECs. The overexpression of miR-92a-3p enhanced apoptosis and phosphorylation levels of JNK and p38 MAPK as well as inhibited proliferation in ox-LDL-induced HUVECs. In addition, SIRT6 was a target of miR-92a-3p. miR-92a-3p negatively regulated SIRT6 expression in ox-LDL-induced HUVECs to activate MAPK signaling pathway in vitro. In summary, miR-92a-3p promoted HUVECs apoptosis and suppressed proliferation in ox-LDL-induced HUVECs by targeting SIRT6 expression and activating MAPK signaling pathway.

Oxylipin regulation by phenolic compounds from coffee beverage: Positive outcomes from a randomized controlled trial in healthy adults and macrophage derived foam cells.

Oxylipins are considered biomarkers related to cardiovascular diseases (CVDs). They are generated in vivo via the oxygenation of polyunsaturated fatty acids as a result of oxidative stress and inflammation. Oxylipins are involved in vascular functions and are produced during foam cell formation in atherogenesis. Additionally, the consumption coffee is associated with the regulation on a particular oxylipin group, the F2t-isoprostanes (F2t-IsoPs). This function has been attributed to the chlorogenic acids (CGAs) from the coffee beverage. Considering the anti-inflammatory and antioxidant properties of CGAs, we evaluated the effects of two types of coffee that provided 787 mg CGAs/day (Coffee A) and 407 mg CGAs/day (Coffee B) by reducing 35 selected oxylipins in healthy subjects. Furthermore, we assessed the effect of CGAs on the cellular proatherogenic response in foam cells by using an oxidized LDL (oxLDL)-macrophage interaction model. After eight weeks of coffee consumption, the contents of 12 urine oxylipins were reduced. However, the effect of Coffee A showed a stronger decrease in IsoPs, dihomo-IsoPs, prostaglandins (PGs) and PG metabolites, probably due to its higher content of CGAs. Neither of the two coffees reduced the levels of oxLDL. Moreover, the in vitro oxylipin induction by oxLDL on foam cells was ameliorated by phenolic acids and CGAs, including the inhibition of IsoPs and PGs by caffeoylquinic and dicaffeoylquinic acids, respectively, while the phenolic acids maintained both antioxidant and anti-inflammatory activities. These findings suggest that coffee antioxidants are strong regulators of oxylipins related to CVDs. The clinical trial was registered on the International Clinical Trials Registry Platform, WHO primary registry (RPCEC00000168).

ABCA1 gene R1587K polymorphism could be associated with metabolic syndrome and increased plasma triglyceride concentration in adults from northern Mexico.

INTRODUCTION: Objectives: to investigate the relationship of R1587K genotypes with cardiovascular (CV) risk, metabolic syndrome (MetS), lipid profile, paraoxonase-1 (PON1) activity, and anti-oxLDL titers. Methods: we performed a cross-sectional study in 57 northern Mexican adults with no reported diseases. The ABCA1 R1587K SNP was detected by real-time polymerase chain reaction (qPCR) using TaqMan allelic discrimination probes. We evaluated the relationship of R1587K with metabolic syndrome and clinical parameters including lipid profile, glucose and insulin, PON1 activity and concentration, anti-oxLDL antibodies, anthropometry and body-composition parameters, and the atherogenic index of plasma calculation. Results: our results show higher triglyceride levels in the RK + KK carriers as compared to RR carriers (p = 0.031). An association between the RK + KK genotype and the presence of MetS (OR = 4.566, 95% CI = 1.386-14.92, p = 0.010) and a tendency towards high CV risk (OR = 3.317, 95% CI = 0.910-8.611, p = 0.069) was observed in comparison to RR carriers; however, there were no differences in HDL-C levels, PON1 activity and concentration, and anti-oxLDL titers among the R1587K genotypes. Conclusions: in the northern Mexican population, the ABCA1 gene R1587K SNP is present and the RK + KK genotypes are associated with MetS and increased triglyceride concentrations; therefore, it could be a CV risk biomarker. Nevertheless there is a need for further confirmation in longitudinal studies.

INTRODUCCIÓN: Objetivo: investigar la relación de los genotipos del SNP R1587K con el riesgo cardiovascular (CV), el síndrome metabólico (SM), el perfil de lípidos, la actividad de paraoxonasa 1 (PON1) y los anticuerpos contra las LDL oxidadas (anti-oxLDL). Métodos: se realizó un estudio transversal con 57 adultos del norte de México que reportaron no tener enfermedades diagnosticadas. El SNP R1587K del gen ABCA1 se detectó a través de PCR en tiempo real (qPCR) usando sondas TaqMan para discriminación alélica. Para evaluar la asociación del SNP R1587K con el SM y determinados parámetros clínicos se determinaron el perfil de lípidos, los niveles de glucosa e insulina, la actividad y concentración de PON1, los anticuerpos anti-oxLDL, los parámetros antropométricos y de composición corporal, y el cálculo del índice aterogénico en plasma. Resultados: los resultados mostraron mayores niveles de triglicéridos en los portadores del genotipo RR + KK que en los portadores de RR (p = 0,031). Se observó una asociación entre el genotipo RK + KK y la presencia de SM (OR = 4,566, IC 95% = 1,386-14,92, p = 0,010) y una tendencia hacia un mayor riesgo cardiovascular (OR = 3,317, IC 95% = 0,910-8,611, p = 0,069) al compararlos con los portadores de RR. No se encontraron diferencias en los niveles de HDL-C, la actividad y concentración de PON1 y los anti-oxLDL entre los genotipos R1587K. Conclusiones: el SNP R1587K del gen ABCA1 se encuentra presente en la población del norte de México y el genotipo RK + KK se asocia con el SM y concentraciones elevadas de triglicéridos, por lo que este SNP podría ser un biomarcador de riesgo cardiovascular. Sin embargo, se necesita confirmación a través de estudios longitudinales. .

Up-regulated miR-106b inhibits ox-LDL-induced endothelial cell apoptosis in atherosclerosis

This research aimed to explore the molecular mechanism of microRNA (miR)-106b in cell apoptosis of atherosclerosis (AS). Human aortic endothelial cells (HAECs) were divided into control group, oxidized-low-density lipoproteins (ox-LDL) group, miR-106b NC+ox-LDL group, miR-106b mimics+ox-LDL group, miR-106b mimics+PTEN+ox-LDL group, and miR-106b mimics+empty+ox-LDL group. Real-time fluorescence quantitative polymerase chain reaction, cholecystokinin, TdT-mediated biotinylated nick end-labeling assay, luciferase reporter gene assay, and flow cytometry analysis were performed to determine the morphology, proliferation, and apoptosis in HSECs. Moreover, the levels of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), Bcl-2, p-P13K, and p-AKT in HAECs were detected by western blot. MiR-106b was down-regulated in ox-LDL-induced HAECs. PTEN was the target gene of miR-106b-5p. Overexpression of PTEN inhibited the anti-apoptotic effect of miR-106b. Compared with the control group, the proportion and number of HAECs apoptosis and Bax, caspase-3, and caspase-9 expression in ox-LDL and miR-106b mimics+PTEN+ox-LDL groups were significantly increased (all P<0.05). Moreover, the activity of HAECs and Bcl-2 were decreased significantly (all P<0.05). Overexpression of miR-106b in ox-LDL-induced AS inhibited endothelial cell apoptosis. Furthermore, miR-106b might activate the PI3K/AKT pathway by down-regulating the expression of PTEN in ox-LDL-induced HAECs.

Relación entre el índice lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) con enzimas antioxidantes y el índice oxLDL/HDL.

INTRODUCTION: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. OBJECTIVE: To assess the association of the index with oxidative stress markers. METHODS: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. RESULTS: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). CONCLUSIONS: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

INTRODUCCIÓN: El índice de lipoproteínas de baja densidad (LDL)/lipoproteínas de alta densidad (HDL) es un factor predictivo de aterosclerosis, la cual está asociada con modificaciones oxidativas. OBJETIVO: Evaluar la asociación del índice con marcadores de estrés oxidativo. MÉTODO: Se incluyeron 444 sujetos, caracterizados clínica, antropométrica y bioquímicamente; se cuantificó superóxido dismutasa, glutation peroxidasa 3 (GPx3), magnesio e índice LDL oxidadas (oxLDL/HDL). RESULTADOS: La disminución en 1.014 unidades del índice LDL/HDL se asoció con aumento de 1 unidad/mL de superóxido dismutasa (p = 0.030) y la de 0.023 unidades con aumento de 1 nmol/minuto/mL de GPx3 (p < 0.0005). El aumento en 1 unidad del índice se asoció con aumento de 0.831 unidades en el índice oxLDL/HDL (p < 0.05). Después de controlar el efecto del sexo, edad, fumar, obesidad y resistencia a la insulina, la reducción de 0.001 por unidad del índice se asoció con aumento de 1 µg/g de magnesio en uñas (p = 0.020). CONCLUSIONES: El índice LDL/HDL presenta relación inversa con el estado antioxidante y relación directa con el estado de oxidación, independientemente de otros factores de riesgo cardiovascular y de estrés oxidativo.

Stanozolol promotes lipid deposition in the aorta through an imbalance in inflammatory cytokines and oxidative status in LDLr knockout mice fed a normal diet.

The aim of the study was to evaluate the effect of an anabolic steroid, stanozolol, in a model of atherosclerosis and to investigate the involvement of the modulation of the inflammatory cytokines and oxidative stress in vascular lipid deposition. Low-density lipid receptor-deficient (LDLr-/-) mice were fed a standard chow diet and were each week injected subcutaneously either saline (control C group) or 20 mg/kg stanozolol (S group). After 8 weeks, the levels of cholesterol, oxidized LDL (OxLDL) and cytokines were measured in plasma, lipid deposition in aorta was evaluated by en face analysis, and thiobarbituric acid-reactive substances and oxidation protein were determined in liver. The S group demonstrated increases in vascular lipid deposition, triglycerides and non-HDL cholesterol levels. Stanozolol increased tumour necrosis factor alpha (TNF-α) and decreased interleukin-10 as well as increased the TNF-α/IL-10 ratio. Furthermore, oxidative stress was observed in the S group, as indicated by an increase in the plasma OxLDL, as well as by lipid peroxidation and oxidation of proteins in the liver. Chronic treatment with stanozolol promoted lipid deposition in the LDLr-/- mice that could be attributed to a modification of the circulating cytokine levels and systemic oxidative stress. Our results suggest that the anabolic steroid stanozolol in the absence of functional LDL receptors by increasing systemic inflammation and oxidative stress may increase the risk of development and progression of atherosclerosis.

LOX-1 activation by oxLDL triggers an epithelial mesenchymal transition and promotes tumorigenic potential in prostate cancer cells.

Obesity is related to an increased risk of developing prostate cancer with high malignancy stages or metastasis. Recent results demonstrated that LOX-1, a receptor associated with obesity and atherosclerosis, is overexpressed in advanced and metastatic prostate cancer. Furthermore, high levels of oxLDL, the main ligand for LOX-1, have been found in patients with advanced prostate cancer. However, the role of LOX-1 in prostate cancer has not been unraveled completely yet. Here, we show that LOX-1 is overexpressed in prostate cancer cells and its activation by oxLDL promotes an epithelial to mesenchymal transition, through of lowered expression of epithelial markers (E-cadherin and plakoglobin) and an increased expression of mesenchymal markers (vimentin, N-cadherin, snail, slug, MMP-2 and MMP-9). Consequently, LOX-1 activation by oxLDL promotes actin cytoskeleton restructuration and MMP-2 and MMP-9 activity inducing prostate cancer cell invasion and migration. Additionally, LOX-1 increased the tumorigenic potential of prostate cancer cells and its expression was necessary for tumor growth in nude mice. In conclusion, our results suggest that oxLDL/LOX-1 could be ones of mechanisms that explain why obese patients with prostate cancer have an accelerated tumor progression and a greater probability of developing metastasis.

Oxidized LDL triggers changes in oxidative stress and inflammatory biomarkers in human macrophages.

Oxidized low-density lipoprotein (oxLDL) is a well-recognized proatherogenic particle that functions in atherosclerosis. In this study, we established conditions to generate human oxLDL, characterized according to the grade of lipid and protein oxidation, particle size and oxylipin content. The induction effect of the cellular proatherogenic response was assessed in foam cells by using an oxLDL-macrophage interaction model. Uptake of oxLDL, reactive oxygen species production and expression of oxLDL receptors (CD36, SR-A and LOX-1) were significantly increased in THP-1 macrophages. Analyses of 35 oxylipins revealed that isoprostanes (IsoP) and prostaglandins (PGs) derived from the oxidation of arachidonic, dihomo gamma-linolenic and eicosapentaenoic acids were strongly and significantly induced in macrophages stimulated with oxLDL. Importantly, the main metabolites responsible for the THP1-macrophage response to oxLDL exposure were the oxidative stress markers 5-epi-5-F2t-IsoP, 15-E1t-IsoP, 8-F3t-IsoP and 15-keto-15-F2t-IsoP as well as inflammatory markers PGDM, 17-trans-PGF3α, and 11ß-PGF2α, all of which are reported here, for the first time, to function in the interaction of oxLDL with THP-1 macrophages. By contrast, a salvage pathway mediated by anti-inflammatory PGs (PGE1 and 17-trans-PGF3α) was also identified, suggesting a response to oxLDL-induced injury. In conclusion, when THP-1 macrophages were treated with oxLDL, a specific induction of biomarkers related to oxidative stress and inflammation was triggered. This work contributes to our understanding of initial atherogenic events mediated by oxLDL-macrophage interactions and helps to generate new approaches for their modulation.

Influência da doença periodontal sobre os fatores de risco para aterosclerose em pacientes portadores de Diabetes Mellitus / Influence of periodontal disease on risk factors for atherosclerosis in patients with Diabetes Mellitus

A Doença Periodontal (DP) e o Diabetes Mellitus tipo 2 (DM2) apresentam a mesma etiopatogênese inflamatória e demonstram uma relação bidirecional, pois DM2 afeta a severidade da DP, e esta pode contribuir para a carga inflamatória total do indivíduo, influenciando a evolução do DM2. O objetivo do presente estudo foi avaliar os fatores de risco para o desenvolvimento de aterosclerose em pacientes portadores de DM2, com e sem periodontite crônica. Foram analisados 48 pacientes, os quais foram divididos em 2 grupos: Teste (pacientes diabéticos com periodontite crônica) e Controle (pacientes diabéticos sem periodontite crônica). O grupo teste foi tratado com debridamento periodontal e o grupo controle recebeu profilaxia supragengival. Ambos os grupos receberam controle de placa a cada 3 meses. No baseline e 6 meses após o tratamento, foi realizada tomada dos parâmetros clínicos periodontais (IP, IG, PS, RG e NIC) e coleta de sangue para avaliação dos marcadores séricos inflamatórios (oxLDL, CT, TG, LDL, HDL, glicose, HbA1c, PCRus, leucócitos e neutrófilos). Os parâmetros periodontais mostraram melhora significativa (p<0,05) no grupo teste, exceto RG. IP e IG também diminuíram significativamente no grupo controle após 6 meses. CT e HbA1c apresentaram taxas significativamente maiores no grupo teste, em comparação com o grupo controle. As taxas de PCR-us e HbA1c diminuíram significativamente no grupo teste após a terapia periodontal. A contagem de leucócitos mostrou uma diminuição relevante no grupo controle durante o tempo do estudo. A terapia periodontal promove melhoras nos parâmetros clínicos periodontais, nos parâmetros inflamatórios e nas taxas de HbA1c em pacientes portadores de DM2 e periodontite, mas não interfere nos níveis séricos de oxLDL(AU)

Periodontal Disease (DP) and Type 2 Diabetes Mellitus (DM2) present the same inflammatory etiopathogenesis and demonstrate a bidirectional relationship, since DM2 affects the severity of PD, and this may contribute to the individual's total inflammatory load, influencing the evolution of DM2. The objective of the present study was to evaluate the risk factors for the development of atherosclerosis in patients with T2DM, with and without chronic periodontitis. We analyzed 48 patients, who were divided into 2 groups: Test (diabetic patients with chronic periodontitis) and Control (diabetic patients without chronic periodontitis). The test group was treated with periodontal debridement and the control group received supragingival prophylaxis. Both groups received plaque control every 3 months. Periodontal clinical parameters (IP, IG, PS, RG and NIC) and collection of blood for evaluation of serum inflammatory markers (oxLDL, CT, TG, LDL, HDL, glucose, HbA1c, hs-CRP, leukocytes and neutrophils). The periodontal parameters showed significant improvement (p <0.05) in the test group, except for RG. IP and IG also decreased significantly in the control group after 6 months. CT and HbA1c presented significantly higher rates in the test group compared to the control group. Rates of Hs-1c and HbA1c decreased significantly in the test group after periodontal therapy. The leukocyte count showed a significant decrease in the control group during the study time. Periodontal therapy promotes improvements in periodontal clinical parameters, inflammatory parameters and HbA1c rates in patients with DM2 and periodontitis, but does not interfere with serum levels of oxLDL(AU)

A novel functionalization method for carbon nanotubes to repel ox-LDL in treatments after stent placement.

Carbon nanotubes (CNT) can be chemically modified by doping or functionalization to change the chemical and surface properties. These characteristic makes to CNT candidates for multiple applications including medical field in cardiovascular area. A novel method to CNT functionalization by formation of two compounds: α-bromoacid and the organic compound 2-(methacryloyloxy) ethyl phosphorylcholine (MPC), will be discussed in this article. According to results, CNT are suggested like candidates to repel oxidized low-density lipoproteins (ox-LDL) to prevent restenosis. The electronegative character on surface of functionalized CNT (F-CNT) is shown by wettability analysis observing a repellent behaviour in contact with ox-LDL after functionalization route. Here we analyse the toxicity of CNT and F-CNT on HepG2 cell line and find no damage to the cell membrane of HepG2 cells in concentration at doses below 1mg/ml.

Associations between CD36 gene polymorphisms and susceptibility to coronary artery heart disease

Associations between polymorphisms of the CD36 gene and susceptibility to coronary artery heart disease (CHD) are not clear. We assessed allele frequencies and genotype distributions of CD36 gene polymorphisms in 112 CHD patients and 129 control patients using semi-quantitative polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Additionally, we detected CD36 mRNA expression by real-time quantitative PCR, and we quantified plasma levels of oxidized low-density lipoprotein (ox-LDL) using an enzyme-linked immunosorbent assay (ELISA). There were no significant differences between the two groups (P>0.05) in allele frequencies of rs1761667 or in genotype distribution and allele frequencies of rs3173798. The genotype distribution of rs1761667 significantly differed between CHD patients and controls (P=0.034), with a significantly higher frequency of the AG genotype in the CHD group compared to the control group (P=0.011). The plasma levels of ox-LDL in patients with the AG genotype were remarkably higher than those with the GG and AA genotypes (P=0.010). In a randomized sample taken from patients in the two groups, the CD36 mRNA expression of the CHD patients was higher than that of the controls. In CHD patients, the CD36 mRNA expression in AG genotype patients was remarkably higher than in those with an AA genotype (P=0.005). After adjusted logistic regression analysis, the AG genotype of rs1761667 was associated with an increased risk of CHD (OR=2.337, 95% CI=1.336-4.087, P=0.003). In conclusion, the rs1761667 polymorphism may be closely associated with developing CHD in the Chongqing Han population of China, and an AG genotype may be a genetic susceptibility factor for CHD.

Ox-LDL increases OX40L in endothelial cells through a LOX-1-dependent mechanism

Oxidative low-density lipoprotein (Ox-LDL) is a key risk factor for the development of atherosclerosis, and it can stimulate the expression of a variety of inflammatory signals. As a new and highly sensitive inflammation index, OX40L may be a key to understanding the mechanisms that regulate interactions between cells within the vessel wall and inflammatory mediators during the development of atherosclerosis. To investigate whether Ox-LDL regulates OX40L expression through an oxidized LDL-1 receptor (LOX-1)-mediated mechanism, we investigated the effect of different concentrations of Ox-LDL (50, 100, 150 µg/mL) on endothelial cell proliferation and apoptosis. Stimulation with Ox-LDL increased OX40L protein 1.44-fold and mRNA 4.0-fold in endothelial cells, and these effects were inhibited by blocking LOX-1. These results indicate that LOX-1 plays an important role in the chronic inflammatory process in blood vessel walls. Inhibiting LOX-1 may reduce blood vessel inflammation and provide a therapeutic option to limit atherosclerosis progression.

Reduced plasma adiponectin levels relative to oxidized low density lipoprotein and nitric oxide in coronary artery disease patients

INTRODUCTION: Adiponectin is a circulating hormone that is produced exclusively by adipocytes and has antiinflammatory and anti-atherogenic properties. The hypothesis that there are differences in adiponectin levels between stable and unstable coronary-artery disease patients remains controversial. Furthermore, the potential relationships between the plasma adiponectin level and the inflammatory and non-inflammatory markers (oxidized low density lipoprotein and nitric oxide) in patients with stable and unstable coronary-artery disease relative to normal subjects have not been assessed. OBJECTIVES: To assess whether plasma adiponectin levels differ among patients with stable and unstable coronary-artery disease and among control subjects, and to correlate plasma adiponectin level with inflammatory and clinical risk factors (such as oxidized-LDL and nitric oxide) in these patients. METHODS: This study included 50 control subjects, 50 stable angina patients and 50 unstable angina patients with angiographically documented coronary-artery disease. Plasma adiponectin and oxidized-LDL levels were determined using an enzyme immunoassay. Plasma nitric oxide, high sensitivity C-reactive protein and lipid profile levels were also measured. RESULTS: Plasma adiponectin levels were lower in the unstable angina patients (4.9 ± 1.30 µg/mL) than in the stable angina patients (6.34 ± 1.0 µg/mL) or in the controls (9.25 ± 1.8 µg/mL); these levels were also significantly lower in stable angina patients versus controls (p<0.001). Plasma adiponectin levels were negatively correlated with oxidized-LDL, high sensitivity C-reactive protein, lipid profile and other clinical risk factors but positively correlated with nitric oxide. CONCLUSION: Plasma adiponectin levels were found to be lower in both stable and unstable angina patients relative to control subjects, and the correlation between plasma adiponectin and cardiovascular markers is weakened in these patients.