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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Untersuchung der Entstehung von intrazellulärem oxidativem Stress unter dem Einfluss von oxidiertem low density lipoprotein

Bauer, Tanja January 2010 (has links) (PDF)
Zusammenfassend konnte durch diese Arbeit gezeigt werden, dass es unter dem Einfluss von oxLDL unabhängig von der intrazellulären Aufnahme und der Aktivierung der NAD(P)H-Oxidase sowohl in glatten Muskelzellen als auch in Endothelzellen zur Bildung von oxidativem Stress kommt. Einzelne Untergruppen der dabei generierten ROS konnten nicht nachgewiesen werden. Zudem konnte die extrazelluläre Bildung von O2•- durch oxLDL gezeigt werden. In auf dieser Arbeit basierenden nachfolgenden Arbeiten konnte nachgewiesen werden, dass die oxLDL-immanenten oxidativen Reaktionsketten bzw. Emissionsketten von reaktiven Radikalen nicht alleinig über die Aufnahme des Partikels an die Zellen weitergegeben werden müssen, sondern dass der physische Kontakt von zellulären Lipidmembranen mit den oxLDL-Lipiden ausreicht. / In summary, it was shown that under the influence of oxLDL independently of the intracellular uptake and activation of NAD(P)H oxidase in both smooth muscle cells and endothelial cells oxidative stress was produced. Some subgroups of the thereby generated ROS could not be detected. Also the extracellular formation of O2•- by oxLDL was shown. In following studies could be proved, that oxLDL-intrinsic oxidative reaction chains and emission chains of reactive radicals not solely passed on the inclusion of the particle to the cells, but that the physical contact of cellular lipid membranes with the oxLDL lipids is sufficient.
2

Mechanisms of 7,8-dihydroneopterin protection of macrophages from cytotoxicity

Shchepetkina, Anastasia January 2013 (has links)
Gamma-interferon stimulates human macrophages to produce of 7,8-dihydroneopterin (7,8-NP). 7,8-NP and its oxidation product neopterin are excellent inflammatory markers for a variety of chronic conditions, including atherosclerosis. The biological significance of 7,8-NP in atherosclerosis is not fully understood, but 7,8-NP has been shown to protect macrophage cells from oxidised low density lipoprotein (oxLDL). Cellular accumulation of oxLDL-derived lipids and oxLDL-induced cytotoxicity are major drivers of atherosclerotic plaque progression. This thesis investigated the mechanisms of 7,8-NP-mediated protection against oxLDL-induced damage to macrophage cells. The research assessed the relative contribution of the previously identifyed antioxidant capacity of 7,8-NP and its ability to down-regulate oxLDL uptake. OxLDL cytotoxicity was characterised by high intracellular oxidative stress within the first 12 hours of exposure, which was critical to oxLDL toxicity. Exogenously added 7,8-NP effectively scavenged the intracellular oxidants generated in response to oxLDL, shown by the oxidation of 7,8-NP to neopterin. The ability of 7,8-NP to alleviate oxidative stress during the critical time-frame of acute toxicity was the primary mechanism of protection. 7,8-NP was also found to down-regulate the levels of intracellular oxysterol esters in oxLDL-treated macrophages. This decrease was associated with the reduction of CD36 scavenger receptor protein and mRNA expression. The late onset of these processes in the second half of the 24 hour incubation highlighted their potential role in foam cell formation. Research indicated that 7,8-NP may play a role in the reverse cholesterol transport in these cholesterol ester-loaded cells. The CD36 down-regulation by 7,8-NP did not protect macrophages from acute oxLDL cytotoxicity. This research reveals novel detail about the mechanism of 7,8-NP protection of macrophages from cytotoxic effects of oxLDL. It is suggested that 7,8-NP may protect macrophage cells in the atherosclerotic plaques by scavenging ROS produced during acute cytotoxicity and alleviate oxysterol ester accumulation, thus stabilising macrophage cells during chronic oxLDL exposure.
3

Hidrólise de nucleotídeos de adenina em plaquetas de pacientes com diferentes níveis de colesterol e sua relação com o processo inflamatório / Enzymes that hydrolyze adenine nucleotides of patients with different cholesterol levels and inflammatory processes

Duarte, Marta Maria Medeiros Frescura 10 October 2006 (has links)
The activity of NTPDase (EC 3.6.1.5, apyrase, CD39) was verified in platelets from patients with increasing cholesterol levels. A possible association between cholesterol levels and inflammatory markers, such as oxidized low density lipoprotein (oxLDL), highly sensitive C-reactive protein (hsCRP) and oxLDL autoantibodies was also investigated. The following groups were studied: group I (< 150 mg/dl), group II (151 to 200 mg/dl); group III: (201 to 250 mg/dl); group IV (> 251 mg/dl) of cholesterol. The results demonstrated that both ATP and ADP hydrolysis were enhanced as a function of cholesterol levels. The LDL levels increased concomitantly with total cholesterol levels. The triglyceride levels were increased in the group with total cholesterol above 251 mg/dl. oxLDL levels were elevated in groups II, III and IV. hsCRP was elevated in the group with cholesterol higher than 251 mg/dl. oxLDL autoantibodies were elevated in groups III and IV. TBARS content was enhanced as a function of cholesterol levels. In summary, hypercholesterolemia is associated with an enhanced of inflammatory response and ATP and ADP hydrolysis. The increase in NTPDase activity is possibly related to a compensatory response to the inflammatory and pro-oxidative state associated with hypercholesterolemia. / A atividade da NTPDase (EC 3.6.1.5, apyrase, CD39) foi verificada em plaquetas de pacientes com diferentes níveis de colesterol. Uma possível associação entre os níveis de colesterol e os marcadores inflamatórios como LDL oxidado (oxLDL), proteína C reativa ultrasensível (hsCRP) e anticopos anti-LDL oxidado (Anti-oxLDL) foi investigado. Os seguintes grupos foram estudados: grupo I (< 150 mg/dl), grupo II (151 a 200 mg/dl); grupo III: (201 a 250 mg/dl); grupo IV (> 251 mg/dl) de colesterol. Os resultados demonstraram que a hidrólise dos nucleotídeos (ATP e ADP) aumentou em função dos níveis de colesterol. Os níveis de LDL aumentaram concomitantemente com os níveis de colesterol total. Os níveis de triglicerídeos foram elevados no grupo com colesterol total acima de 251 mg/dl. Os níveis de oxLDL foram elevados nos grupos II, III and IV. A hsCRP foi elevada no grupo com cholesterol maior que 251 mg/dl. Os Anti-oxLDL foram elevados nos grupos III e IV. O conteúdo de TBARS foi aumentando em função dos níveis de colesterol. Em resumo, a hipercolesterolemia está associada com o aumento da resposta inflamatória e hidrólise de ATP e ADP. O aumento da atividade da NTPDase está possivelmente relacionado com uma resposta compensatória ao estado inflamatório e pró-oxidativo associado com a hipercolesterolemia.
4

Low density lipoprotein induction of intracellular oxidants production

Othman, Mohd Izani January 2015 (has links)
Atherosclerosis is a complex cardiovascular disease characterized by chronic progressive inflammation of the arteries. The progression of atherosclerosis from fatty streak to advance atherosclerotic plaque involves the development of a necrotic core region consists of cholesterol, lipids, calcium (Ca²⁺), dead cells and other cellular debris. Macrophage infiltrations occurred in all stages of atherosclerotic progression and they are abundantly found in atherosclerotic plaques. Oxidised low density lipoprotein (oxLDL) plays a vital role in the initiation and development of atherosclerosis. OxLDL is present within atherosclerotic plaque and has been shown to be cytotoxic to various types of cells including macrophages. This research initially examined the cytotoxic effects of copper oxidised LDL on U937, human monocytes and HMDM cells. As expected oxLDL was cytotoxic; causing rapid, concentration and time dependent cell viability loss in all types of cells examined. Examination of the cell morphology showed that oxLDL caused a necrotic like cell death characterised by cell swelling and lysis. Flow cytometric assay coupled with propidium iodide (PI) staining of necrotic cells was compared to MTT reduction assays of cell viability. The flow cytometric technique had the advantage over the MTT reduction assay of being rapid and showing both the live and dead cell levels at an individual cell level. The progression of oxLDL-induced cell death correlated with the rapid increased in intracellular ROS production in the cytosol and the mitochondria. Immunoblotting results showed that oxLDL induced NADPH oxidase (NOX) activation and increased p47phox expression. This suggests NOX as the generator of reactive oxygen species (ROS) induced by oxLDL in these cells. However, apocynin and VAS2870, the two NOX inhibitors used in this study, were unable to inhibit the ROS generation caused by the oxLDL. This suggests that either these inhibitors are unable to inhibit the targeted NOX or other sources of ROS might exist and contributed to the overall increase in oxidative flux. OxLDL caused a rapid increase in cytosolic Ca²⁺ level. This was contributed by the extracellular Ca²⁺ source as well as Ca²⁺ mobilisation from the intracellular stores such as endoplasmic reticulum (ER). OxLDL-induced intracellular Ca²⁺ increase also correlated with the increase in intracellular ROS. Nevertheless, blocking of oxLDL-induced intracellular Ca²⁺ elevation by Ca²⁺ chelator, EGTA, did not reduce intracellular ROS generation. Accordingly, this suggests that oxLDL-induced intracellular Ca²⁺ increase is not the cause for oxLDL-induced cell death. Additionally, oxLDL may also initiate a Ca²⁺-independent cell death pathway. The excess cytosolic Ca²⁺ taken up by the mitochondria may be detrimental and could result in mitochondrial Ca²⁺ overload. This will increase mitochondrial ROS production and initiate mitochondrial permeability transition (MPT) pores opening. Consequently, this could collapse the mitochondrial membrane potential ( m) due to the rupture of outer mitochondrial membrane (OMM) and resulted in cell death. Blocking of Ca²⁺ uptake into the mitochondria by ruthenium red protected cells from oxLDL-mediated cell death, possibly by reducing ROS production and preventing MPT activation. This study also demonstrated the protective effect of 7,8-dihydroneopterin (7,8-NP) on oxLDL-induced oxidative stress. 7,8-NP protected cells from oxLDL-induced intracellular ROS generation and cell viability loss. Intracellular Ca²⁺ increase was also reduced by 7,8-NP in particular after 3 hours incubation with oxLDL. The action of 7,8-NP was better than that of apocynin in protecting U937 cells from oxLDL suggests its potential ability to scavenge ROS from various sources. Studies have implicated the involvement of H₂S in various biological processes including atherosclerosis. Thus, the disruption of H₂S homeostasis may contribute to the progression of atherosclerosis. Slow releasing H₂S molecules (H₂S donors) have been developed for a controlled and stable delivery of H₂S to cells. In this study, specific H₂S donors, including one which targets the mitochondria, were found to be protective against oxLDL-induced cell death in U937, human monocytes and HMDM cells. Although the exact mechanism is yet to be elucidated, these H₂S donors were shown to block the elevation of intracellular Ca²⁺ and ROS production mediated by oxLDL. Therefore, these H₂S donors could be the potential candidates for future development of therapeutics in treating atherosclerosis.
5

Suco de laranja tem efeito sinérgico à estatina e ao genfibrozila no tratamento da aterosclerose / Orange juice has a synergic effect to statin and gemfibrozil in the treat-ment of atherosclerosis

Raposo Filho, José Joaquim Fernandes 23 August 2010 (has links)
FUNDAMENTO: O suco de laranja (Citrus sinensis) é rico em vitami-na C, folatos e seu principal flavonóide, a hesperidina, cuja conformação es-pacial é semelhante à genisteína de soja que tem ação favorável sobre o aparelho cardiovascular. A vitamina C é conhecida como potente inibidor da peroxidação lipídica. Mas sua capacidade por possuir efeitos terapêuticos no tratamento da aterosclerose é pouco estudada. OBJETIVO: O presente tra-balho visa a determinar se o suco de laranja pode ter efeito aditivo no trata-mento com estatinas e fibratos, reduzindo placas ateroscleróticas e a quanti-dade de LDL Oxidado (LDL ox). MÉTODOS: Análise do efeito do suco nas dimensões de cortes histológicos e na quantidade de anticorpos anti LDL oxidado (antiLDLox) em lesões ateroscleróticas na aorta de coelhos. RE-SULTADOS: O suco de laranja potencializou a redução de área de placas ateroscleróticas e a quantidade de LDL(ox) em relação às reduções obtidas com rosuvastatina e gemfibrozil. CONCLUSÕES: O suco de laranja tem efei-to sinérgico ao tratamento convencional da aterosclerose de coelhos / Statins and fibrates have been used as anti-atherosclerotic drugs. However, a high number of treated patients still present acute events and death by atherosclerotic complications. Flavonoid ingestion has been associ-ated with lower risk of death, lower incidence of coronary artery disease and more preserved endothelial function in atherosclerotic patients. Orange juice is rich in C vitamine, a well known potent inhibitor of lipidic peroxidation, and in flavonoids, mainly the hesperidine that seems the soy bean genisteine, which is associated with decrease LDL and increase HDL. Objective: In this work we studied if orange juice has addictive effect to statin and gemfibrozil in the treatment of rabbit atherosclerosis, reducing plaque area and oxidate LDL (LDLox). Methods: Five group of atherosclerotic rabbits, fed with 1% cholesterol enriched diet during 12 weeks, were analyzed: GI - received no treatment, GII Gemfibrozil 600mg/day, GIII treated with Gemfibrozil 600mg/day + orange juice, GIV - rosuvastatin/10mg / day and GV - rosu-vastatin/10mg / day + orange juice. The most severe atherosclerotic cross section in ascendant aorta was analyzed in H&E and anti-oxidated LDL (oxLDL) immunostained slides, obtaining intimal area, total vessel area, % luminal obstruction and % oxLDL area in intima. Results: The means (stan-dard deviations) of plaque area and % plaque area of oxLDL in GI were 1.05 (0.91) and 0.12 (0.13), with no significant difference with GII animals, respec- tively 3.85 (5.27) and 0.18 (0.22), but significantly reduced in GIII, 0.64 (1.56) and 0.03 (0.05). Similar data were seen in GIV, 2.11 (2.77) and 0.19 (0.25), compared with GV, 0.04 (0.09) and 0.00 (0.00). Conclusion: This work de-monstrates that orange juice has a potential synergistic action with statin and fibrates in reducing atherosclerosis and the mechanism seems to involve in-hibition of oxLDL concentration and migration of smooth muscle cells in the subendothelial space
6

Novos biossensores baseados em anticorpos naturais e sintéticos para detecção de LDL oxidada (oxLDL) usada como biomarcador de aterosclerose. / New biosensors based on natural and synthetic antibodies for the detection of oxidized LDL (oxLDL) used as a biomarker for atherosclerosis.

Gustavo Cabral de Miranda 04 August 2014 (has links)
Vários estudos que tentam compreender a gênese da aterosclerose têm demonstrado evidências que a oxLDL é peça importante para o desenvolvimento da doença, tornando-a um importante marcador. Os objetivos deste trabalho foram propor um novo imunossensor empregando anticorpos monoclonais anti-oxLDL e desenvolver um processo inovador de obtenção de anticorpos plásticos anti-oxLDL. Para construção do imunossensor, a região Fc do anticorpo foi ligada ao eletrodo de trabalho do dispositivo AuSPE (Screen-Printed Gold Electrodes), utilizando cisteamina. Posteriormente, foi adicionado BSA como bloqueador de possíveis regiões livres. Após o bloqueio, o imunossensor foi testado com oxLDL e outros antígenos, como forma de garantir a especificidade. Em relação aos anticorpos plásticos, chamados MAPS, estes foram desenvolvidos contruindo uma camada impressa de forma invertida ao anticorpo plástico SPAN, referência deste trabalho. Após obtenção dos MAPSs, estes passaram por diversos testes, similar ao imunossensor. Os resultados demonstraram excelente sensibilidade e especificidade às moléculas de oxLDL com detecção em tempo real em ambas as metodologias. / Increased levels of plasma oxLDL are associated with atherosclerosis, and the subsequent development of severe cardiovascular diseases that are today a major cause of death in modern countries. It is therefore important to find a reliable and fast assay to determine oxLDL. A new Immunosensor employing three monoclonal antibodies against oxLDL and a backside protein-surface imprinting process are proposed in this work. To generate the Immunosensor the mAbs were set-up by cysteamine on a gold layer of a disposable screen-printed electrode. BSA was immobilized further as bloker. All steps were followed by various characterization techniques such as electrochemical impedance spectroscopy and square wave voltammetry. To generate specific synthetic antibody materials, called MAPS, these were developed with a backside protein-surface imprinting process of the plastic antibody SPAN, the reference of the work. The devices were successfully applied to determine the oxLDL fraction in real serum, without prior dilution or necessary chemical treatment. Overall, these were promising results with the possibility to apply on the practical use of clinical.
7

Novos biossensores baseados em anticorpos naturais e sintéticos para detecção de LDL oxidada (oxLDL) usada como biomarcador de aterosclerose. / New biosensors based on natural and synthetic antibodies for the detection of oxidized LDL (oxLDL) used as a biomarker for atherosclerosis.

Miranda, Gustavo Cabral de 04 August 2014 (has links)
Vários estudos que tentam compreender a gênese da aterosclerose têm demonstrado evidências que a oxLDL é peça importante para o desenvolvimento da doença, tornando-a um importante marcador. Os objetivos deste trabalho foram propor um novo imunossensor empregando anticorpos monoclonais anti-oxLDL e desenvolver um processo inovador de obtenção de anticorpos plásticos anti-oxLDL. Para construção do imunossensor, a região Fc do anticorpo foi ligada ao eletrodo de trabalho do dispositivo AuSPE (Screen-Printed Gold Electrodes), utilizando cisteamina. Posteriormente, foi adicionado BSA como bloqueador de possíveis regiões livres. Após o bloqueio, o imunossensor foi testado com oxLDL e outros antígenos, como forma de garantir a especificidade. Em relação aos anticorpos plásticos, chamados MAPS, estes foram desenvolvidos contruindo uma camada impressa de forma invertida ao anticorpo plástico SPAN, referência deste trabalho. Após obtenção dos MAPSs, estes passaram por diversos testes, similar ao imunossensor. Os resultados demonstraram excelente sensibilidade e especificidade às moléculas de oxLDL com detecção em tempo real em ambas as metodologias. / Increased levels of plasma oxLDL are associated with atherosclerosis, and the subsequent development of severe cardiovascular diseases that are today a major cause of death in modern countries. It is therefore important to find a reliable and fast assay to determine oxLDL. A new Immunosensor employing three monoclonal antibodies against oxLDL and a backside protein-surface imprinting process are proposed in this work. To generate the Immunosensor the mAbs were set-up by cysteamine on a gold layer of a disposable screen-printed electrode. BSA was immobilized further as bloker. All steps were followed by various characterization techniques such as electrochemical impedance spectroscopy and square wave voltammetry. To generate specific synthetic antibody materials, called MAPS, these were developed with a backside protein-surface imprinting process of the plastic antibody SPAN, the reference of the work. The devices were successfully applied to determine the oxLDL fraction in real serum, without prior dilution or necessary chemical treatment. Overall, these were promising results with the possibility to apply on the practical use of clinical.
8

Antioxidative Enzyme und \"oxidized low density lipoprotein\" (oxLDL) in Follikelflüssigkeit und Serum bei IVF - Patientinnen mit Adipositas

Bausenwein, Judith 01 July 2011 (has links)
Adipositas und das polyzystische Ovarsyndrom (PCOS) sind häufig Gründe für Anovulation, Infertilität und unerfüllten Kinderwunsch. Sowohl Adipositas als auch das PCOS können zu einem Ungleichgewicht zwischen Anti- und Prooxidanzien im menschlichen Körper führen. Durch Übergewicht der Prooxidanzien ensteht oxidativer Stress. Reaktive Sauerstoffspezies (reactive oxygen species, ROS) fallen vermehrt an und oxidieren Lipoproteine zu „oxidized low density lipoproteins“ (oxLDL). Durch Bindung von oxLDL an den „lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1)“ wird Apoptose und Autophagie induziert. Wir vermuten, dass sich diese Prozesse auch in der Follikelflüssigkeit (FF), dem Milieu der Eizelle, abspielen und zum Absterben reifender Follikel und somit zur Anovulation und Infertilität führen. Das Ziel dieser Arbeit war es, zu untersuchen, welchen Einfluss Adipositas, hormonelle Stimulation und PCOS auf die enzymatischen Antioxidanzien Superoxiddismutase (SOD), Katalase, Glutathionperoxidase (GPx) und Glutathionreduktase (GR) sowie auf den oxLDL-Spiegel haben. Es wurden Serum und FF von Frauen unter IVF (in vitro Fertilisation) -Therapie untersucht, die anhand ihres Body Mass Index (BMI), des Taille-Hüft-Quotienten (T/H-Quotient) sowie des PCOS in vier Gruppen eingeteilt wurden. Die Konzentration an oxLDL als Repräsentant des oxidativen Systems und die Aktivität der Enzyme SOD, Katalase, GPx und GR, Repräsentaten des antioxidativen Systems, wurden im Serum vor Stimulationsbeginn und zum Zeitpunkt der Follikelpunktion sowie in der FF gemessen. Adipöse Frauen mit und ohne PCOS hatten höhere Konzentrationen an oxLDL in der FF als normalgewichtige. Die oxLDL-Konzentrationen der FF waren 1000-fach niedriger als die der Seren. Interessanterweise waren auch die Katalase-Aktivitäten in der FF adipöser Frauen mit und ohne PCOS höher als die der normalgewichtigen. Zusammenfassend lässt sich folgern, dass erhöhte oxLDL-Konzentrationen in der FF von adipösen Frauen, unabhängig vom Vorliegen eines PCOS, mit einer gesteigerten Katalase-Aktivität und einer niedrigeren IVF-Erfolgsrate assoziiert sind.
9

Suco de laranja tem efeito sinérgico à estatina e ao genfibrozila no tratamento da aterosclerose / Orange juice has a synergic effect to statin and gemfibrozil in the treat-ment of atherosclerosis

José Joaquim Fernandes Raposo Filho 23 August 2010 (has links)
FUNDAMENTO: O suco de laranja (Citrus sinensis) é rico em vitami-na C, folatos e seu principal flavonóide, a hesperidina, cuja conformação es-pacial é semelhante à genisteína de soja que tem ação favorável sobre o aparelho cardiovascular. A vitamina C é conhecida como potente inibidor da peroxidação lipídica. Mas sua capacidade por possuir efeitos terapêuticos no tratamento da aterosclerose é pouco estudada. OBJETIVO: O presente tra-balho visa a determinar se o suco de laranja pode ter efeito aditivo no trata-mento com estatinas e fibratos, reduzindo placas ateroscleróticas e a quanti-dade de LDL Oxidado (LDL ox). MÉTODOS: Análise do efeito do suco nas dimensões de cortes histológicos e na quantidade de anticorpos anti LDL oxidado (antiLDLox) em lesões ateroscleróticas na aorta de coelhos. RE-SULTADOS: O suco de laranja potencializou a redução de área de placas ateroscleróticas e a quantidade de LDL(ox) em relação às reduções obtidas com rosuvastatina e gemfibrozil. CONCLUSÕES: O suco de laranja tem efei-to sinérgico ao tratamento convencional da aterosclerose de coelhos / Statins and fibrates have been used as anti-atherosclerotic drugs. However, a high number of treated patients still present acute events and death by atherosclerotic complications. Flavonoid ingestion has been associ-ated with lower risk of death, lower incidence of coronary artery disease and more preserved endothelial function in atherosclerotic patients. Orange juice is rich in C vitamine, a well known potent inhibitor of lipidic peroxidation, and in flavonoids, mainly the hesperidine that seems the soy bean genisteine, which is associated with decrease LDL and increase HDL. Objective: In this work we studied if orange juice has addictive effect to statin and gemfibrozil in the treatment of rabbit atherosclerosis, reducing plaque area and oxidate LDL (LDLox). Methods: Five group of atherosclerotic rabbits, fed with 1% cholesterol enriched diet during 12 weeks, were analyzed: GI - received no treatment, GII Gemfibrozil 600mg/day, GIII treated with Gemfibrozil 600mg/day + orange juice, GIV - rosuvastatin/10mg / day and GV - rosu-vastatin/10mg / day + orange juice. The most severe atherosclerotic cross section in ascendant aorta was analyzed in H&E and anti-oxidated LDL (oxLDL) immunostained slides, obtaining intimal area, total vessel area, % luminal obstruction and % oxLDL area in intima. Results: The means (stan-dard deviations) of plaque area and % plaque area of oxLDL in GI were 1.05 (0.91) and 0.12 (0.13), with no significant difference with GII animals, respec- tively 3.85 (5.27) and 0.18 (0.22), but significantly reduced in GIII, 0.64 (1.56) and 0.03 (0.05). Similar data were seen in GIV, 2.11 (2.77) and 0.19 (0.25), compared with GV, 0.04 (0.09) and 0.00 (0.00). Conclusion: This work de-monstrates that orange juice has a potential synergistic action with statin and fibrates in reducing atherosclerosis and the mechanism seems to involve in-hibition of oxLDL concentration and migration of smooth muscle cells in the subendothelial space
10

The Anti-angiogenic Functions of Low Density Lipoproteins Subfractions from Patients with Familial Hypercholestrolemia

Liang, Hui-Ting 15 February 2005 (has links)
Compelling evidence indicated that major risk factors for atherosclerosis such as oxidatively modified low density lipoprotein (oxLDL), high glucose, and reactive oxygen species promote endothelial cell apoptosis and thereby may contribute to the initiation of atherosclerotic lesion formation. Using fast protein liquid chromatography (FPLC), plasma LDL from familial hypercholesterolemic (FH) patients were separated into five subfractions, L1¡VL5. Among them, L5 subfraction was highly electronegative and suppressed DNA synthesis in cultured bovine aortic endothelial cells (BAEC) and stimulated mononuclear cell adhesion to cultured endothelial cells in vitro. Because impaired angiogenesis plays an important role in the pathogenesis of atherosclerosis, the anti-angiogenic functions of LDL subfractions from FH subjects were examined. Subconfluent BAEC (6 to 10 passages) maintained in DMEM containing 10% serum were treated with LDL subfractions at a dose of 20 £gg/ml, and the effects on anti-angiogenic functions, including cell proliferation, migration, apoptosis, tube formation, and secretion of matrix metalloproteinase (MMP) were determined. Similar to Cu2+ ox-LDL, FH-L4 and FH-L5 inhibited cell proliferation to 80.9¡Ó2.4% (p<0.05) and 58.5¡Ó4.3% of control (p<0.001), respectively, while the other FH (L1-L3) and all subfractions isolated from normocholesterolemic (N) subjects had negligible effects. Similarly, FH-L4 and -L5, but not FH-L1 to -L3, retarded cell migration to 326.9 ¡Ó 19.4 (p<0.05) and 215¡Ó16 cells (p<0.001 with the control values of 402¡Ó34 cells), respectively. FH-L5 induced almost 20% of BAEC to undergo apoptosis; FH-L4 caused very mild effects, and other subfractions did not affect apoptosis In addition, FH-L4 and -L5 perturbed tube formation by BAEC in culture (5.8¡Ó0.2 and 3.4¡Ó0.4, respectively, versus control 8.5¡Ó1.5 tubes). Finally, FH-L4 and -L5 inhibited secretion of MMP-2 by BAEC (72.7¡Ó6.9 and 18.9¡Ó4.8% of control, respectively). The results demonstrate that FH-L5 potently affects multiple processes that are vital to normal angiogenesis, FH-L4 had milder effects, and other FH and N subfractions had negligible effects. In turn, these effects in vitro on processes pivotal to angiogenesis are consistent with potential effects of ox-LDL on endothelial dysfunction during atherogenesis in vivo.

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