Spelling suggestions: "subject:"apolipoproteins."" "subject:"apolipoproteinas.""
91 |
Capacidade da Lipoproteína de Alta Densidade (HDL) de receber lipídeos em diferentes faixas etárias: um estudo in vitro utilizando uma lipoproteína artificial / Capacity of the High Density Lipoprotein (HDL) to receive lipids in different age: a study in vitro using an artificial nanoemulsionCarolina Heitmann Mares Azevedo 26 September 2007 (has links)
A relação entre transferência de lipídeos, idade e aterogênese são complexas e ainda não estão claras. É possível que a troca de lipídeos esteja alterada com a avançar da idade e relacionada com a Doença Arterial Coronariana (DAC). O objetivo deste trabalho foi verificar a hipótese se em indivíduos mais jovens a habilidade da HDL de receber lipídeos é diferente de indivíduos mais velhos com e sem a evidência clínica da DAC. Dentro desses aspectos, foram determinados o diâmetro da partícula desta lipoproteína, a atividade da Paraoxonase (PON1) e sua capacidade de receber lipídeos. Para tanto, foram estudados 86 indivíduos divididos em quatro grupos: adulto jovem (25±4), meia-idade (42±8), idosos sem evidência clínica de DAC (75±6) e idosos com DAC (74±5). Uma nanoemulsão artificial rica em colesterol (LDE) marcada com 3H-TG e 14C-CL ou 3H-CE e 14C-FL foi incubada com plasma. Após a precipitação de outras lipoproteínas, o sobrenadante contendo HDL foi separado e em seguida, medida a radioatividade. O diâmetro da HDL foi medido por laser scattering (nm). Foram constatadas diferenças significativas entre as taxas de transferência de 3H-éster de colesterol (CE) entre os grupos: adulto jovem (3.7±1.0%); meia idade (4.1 ±0.7%) e idosos (5.3±1.8%);p= 0.024. Também ocorreu diferença entre as taxas de transferência do 14C-fosfolipídeo (FL): adulto jovem (18.7±4.6%), meia idade (18.3 ±4.0%) e idosos (20.6±5.3); p=0.0368. Com relação ao tamanho das partículas de HDL, foi encontrada diferença entre os grupos: os grupos adulto jovem (8.9± 0.3nm) e meia idade (8.9± 0.3nm) apresentaram menores diâmetros de HDL quando comparados ao do grupo de idosos sem evidência clínica da DAC (9.7± 1.6);p= 0,0444. As transferências de lipídeos foram expressas em % de radioatividade. A idade correlacionou-se positivamente com a taxa de transferência do 3H- éster de colesterol (r=0.3365; p=0.0036), com a concentração de colesterol total (r=0.4965; p=0.0001) e com a concentração de HDL colesterol (r=0.3559; p=0.0023). Também houve correlação positiva com o tamanho de HDL (r=0.3695; p=0.0013). Em princípio, os indivíduos idosos sem evidência clínica da DAC, aparentemente têm alguma proteção contra a mesma. Desse modo, com o intuito de saber se os resultados encontrados no presente trabalho sustentam a afirmação acima, foi realizada a comparação desse grupo com um grupo de idosos que apresentavam a DAC. O grupo com DAC apresentou menor tamanho de partícula de HDL (8,7±0,7). As taxas de transferência de 3H-CE e de 14C-FL também foram menores neste grupo (3H-CE=3,1 ±2,3 e 3H-TG= 5,1 ±1 ,6). Devido ao importante papel antiaterogênico da HDL, esses resultados podem ser relevantes para estabelecer novos mecanismos existentes entre os aspectos qualitativos dessa lipoproteína, o avanço da idade e a presença da DAC. / The relationship between transfer of lipids, age and atherogenesis are complex and yet unclear and is possible that the shift of lipids to HDL may be altered by the aging process and related with coronary artery disease (CAD). We tested the hypothesis whether in younger patients the ability of HDL to receive lipids is different from that of elderly patients with or without CAD. Inside of these aspects, the HDL size, the activity of Paraoxonase (PON1) and its capacity to receive lipids was determined. It was studied, 25 younger, 25 middle age, 36 elderly patients with a coronariography and/or a perfusion scintilography on the last 6 months (11 with CAD, 74±5 yo; and 25 patients without proved CAD, 75±6 yo). An artificial cholesterol-rich nanoemulsion labeled with 3H-TG and 14C-FC or H-CE and 14C-PL was incubated, per 1 hour, with plasma. After chemical precipitation of apoB-containing lipoproteins and the nanoemulsion, the supernatant containing HDL was counted for radioactivity. The HDL diameter was measured by laser-light-scattering. Transfer of CE and PL to HDL was smaller in young patients than in the elderly patients without CAD, but the transfer of the other lipids are equal (CE: young= 3.7±1.0%; middle age= 4.1 ±0.7%; elderly without CAD= 5.3±1.8%; p= 0.024 and PL: young= 18.7±4.6%; middle age= 18.3 ±4.0%; elderly without CAD= 20.6±5.3; p=0.0368). The HDL size was greater in elderly group without CAD (9.7± 1.6nm) than in younger (8.9± 0.3nm) and middle age patients (8.9± 0.3nm); p=0,0444. Transfer of lipids to HDL was expressed as % of total incubated radioactivity. The age positively correlated with the transfer of CE (r=0.3365; p=0.0036), with the total cholesterol concentration (r=0.4965; p=0.0001) and with the HDL concentration cholesterol (r=0.3559; p=0.0023). Also had positive correlation with the size of HDL (; p=0.0013). In principle, the aged patients without CAD, have some protection against the same one. In this aspect, with intention to know if the results found in the present work support the affirmation above, was compared this group with a group of aged that presented the CAD. Comparing elderly patients without CAD with elderly patients with CAD, the transfer of CE and FL as well as HDL size was smaller in the CAD group (CE=3.1±2.3 and TG= 5.1±1.6; 8.7±0.7nm). Due to HDL important antiatherogenic roles, this result can be relevant to establish new mechanisms and risk factors in aging and in CAD.
|
92 |
The trypanosome lytic factor of human serum, a Trojan horseVanhollebeke, Benoît 01 December 2008 (has links)
The trypanolytic factor of human serum :a trojan horse.<p><p><p>African trypanosomes, the prototype of which is Trypanosoma brucei, are protozoan parasites of huge clinical, veterinary and economical importance. They develop in the body fluids of various mammals (including humans) where they face and manipulate many different aspects of the immune system. The extent of this interplay is pivotal to both host and parasite survival, and depending on parasite virulence and host susceptibility, infection duration ranges from some months to several years. At the end, host survival is invariably compromised.<p><p>Humans and few other primates provide however a striking exception to this fatal outcome. They are indeed fully protected against most trypanosome infections through the presence in their blood of a so-called trypanosome lytic factor (TLF). The TLF is known to circulate mainly in the form of a high density lipoprotein particle characterized by the simultaneous presence of two primate-specific proteins: haptoglobin-related protein (Hpr) and apolipoprotein L-I (apoL-I).<p><p>We have contributed to delineate the respective roles played by Hpr and apoL-I in the lysis process.<p><p>ApoL-I was shown to be the exclusive toxin of the TLF. In its absence humans get fully susceptible to any trypanosome infection. The toxin was shown to kill the parasite after endocytosis through the generation of ionic pores in the lysosomal membrane. Those pores dissipate membrane potential and trigger the influx of chloride ions from the cytoplasm into the lysosomal compartment, leading to an eventually fatal uncontrolled osmotic phenomenon. <p><p>ApoL-I efficient delivery to the parasite relies on Hpr. African trypanosomes indeed fulfil their heme nutritional requirements by receptor-mediated internalization of the complex formed by haptoglobin, an evolutionary conserved acute-phase protein, and hemoglobin, resulting from physiological intravascular hemolysis. This heme uptake by the auxotrophic parasites contributes to both growth rate and resistance against host oxidative burst. In human serum, the trypanosome receptor is unable to discriminate between Hp and the closely related TLF-bound Hpr, explaining TLF efficient endocytosis.<p><p>As such, the TLF acts as a Trojan horse, killing the parasite from inside the cell after having deceived its vigilance through the high similarity between heme-delivering haptoglobin and toxin-associated Hpr. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
|
93 |
APOL-Mediated trypanolytic activity / Activité trypanolytique des apolipoprotéines L humainesFontaine, Frédéric 12 September 2014 (has links)
Apolipoprotein L1 (APOL1) is a human-specific serum protein bound to high-density lipoprotein (HDL) particles. This protein allows human resistance to infection by African trypanosomes except for two subspecies, Trypanosoma brucei rhodesiense and T. b. gambiense, the causative agents of sleeping sickness or African trypanosomiasis. This disease infects 20 000 people in sub-Saharan Africa and without treatment, infection is almost always fatal. T. b. rhodesiense resists APOL1 through direct protein neutralization by the Serum Resistance-Associated (SRA) protein. T. b. gambiense does not express SRA, and its mechanism of resistance to APOL1 is orchestrated upon a recently characterized multifactorial defense mechanism.<p><p>The mechanism by which the human serum sensitive parasites are killed following APOL1 uptake is described as the result of the lysosomal swelling induced by the generation of ionic pores within the lysosomal membrane.<p>We show here that preventing the osmotic lysosomal swelling in a hyperosmotic culture condition does not prevent the cell death. In addition, APOL1 appears to trigger some programmed cell death events in the cell such as a fast mitochondrial depolarization followed by a DNA laddering and fragmentation. Furthermore, we show an implication of the endonuclease G (TbEndoG), known to be a key actor in the regulation of cell death process and a kinesin (TbKIFC1), which might be the transporter of APOL1 for the endosomes to the mitochondrion.<p> <p>In addition, by producing different recombinant human APOL proteins in E. coli and test their activity on T. brucei, we were able to show that APOL3, an other member of the APOL family, also possesses a trypanolytic activity like APOL1 beneath the fact it is not a secreted protein. APOL3 does not only kill T. b. brucei but is also able to lyse APOL1-resistant subspecies such as rhodesiense and gambiense, in vitro and confirmed in vivo when the recombinant APOL3 were injected in infected mice. A beginning of an action mechanism is described herein showing a pH-independent activity for this protein oppositely to APOL1, conferring its specificity.<p>It is thus conceivable to use this recombinant protein as a first step of a potent curative agent against gambiense or rhodesiense since the few currently available drugs for treatment of African trypanosomiasis, that are outdated, show problems with toxicity and resistance. <p><p>/ <p><p>L’ Apolipoprotéine L1 (APOL1) est une protéine sérique humaine associée aux lipoprotéines de haute densité (HDL). Cette protéine confère la résistance à l'infection des trypanosomes africains à l'exception des deux sous-espèces, Trypanosoma brucei rhodesiense et T. b. gambiense, les agents responsables de la maladie du sommeil ou trypanosomiase africaine. Cette maladie infecte 20 000 personnes en Afrique sub-saharienne et en l'absence de traitement, l'infection est presque toujours mortelle. T. b. rhodesiense résiste à l’APOL1 grâce à une neutralisation directe d’APOL1 par une protéine appelé SRA (Serum Resistant-Associated). T. b. gambiense n'exprime pas SRA, et sa résistance à l’APOL1 est orchestrée par un mécanisme de défense multifactorielle récemment caractérisé 1.<p>Le mécanisme par lequel les parasites sensibles au sérum humain sont tués suivant l’entrée de l’APOL1 est décrit comme le résultat d’un gonflement du lysosome induit par la génération de pores ioniques à l'intérieur de la membrane lysosomiale2. Nous montrons ici que le gonflement osmotique du lysosome peut être empêché en condition de culture hyper osmotique, sans néanmoins empêcher la mort de la cellule. En outre, l’APOL1 semble déclencher des événements de mort cellulaire programmée dans la cellule, tels qu’une dépolarisation mitochondriale rapide suivie d'une fragmentation de l’ADN. De plus, nous montrons une implication de l'endonucléase G (TbEndoG), connu pour être un acteur clé dans la régulation du processus de mort cellulaire et d’une kinésine (TbKIFC1) qui pourrait avoir le rôle de transporter l’APOL1 des endosomes vers la mitochondrie.<p>Nous avons également pu montrer que l’APOL3, un autre membre de la famille des APOLs humaines, possède tout comme l’APOL1, une activité trypanolytique bien que cette protéine ne soit pas sécrétée en condition physiologique. De manière intéressante, l’APOL3 ne tue pas seulement T. b. brucei, mais est également capable de tuer les sous-espèces résistantes à l’APOL1 tels que rhodesiense et gambiense, in vitro et in vivo lorsque de l’APOL3 recombinante est injectée dans des souris infectées. La spécificité d’action de l’APOL3 pourrait être liée à une indépendance au pH, au contraire de l’APOL1. Il pourrait être envisagé d'utiliser cette protéine recombinante comme agent curatif contre gambiense ou rhodesiense du fait que les médicaments actuellement disponibles pour le traitement de la trypanosomiase africaine montrent des problèmes de toxicité et de résistance.<p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
|
94 |
Papel dos lípides plasmáticos e fatores pró-inflamatórios na fisiopatologia da insuficiência cardíaca / Role of plasma lipids and pro inflammatory factors in the patho physiology of heart failureMartinelli, Ana Elisa Marabini 19 May 2017 (has links)
Introdução: A Organização Mundial da Saúde estimou em 2015 que 23 milhões de pessoas em todo o mundo sofrem de insuficiência cardíaca (IC), com taxas de mortalidade equivalentes às do câncer. Níveis mais elevados de HDL-colesterol têm sido associados com maior sobrevivência na IC. É consensual que as várias funções protetoras da HDL devem ser exploradas além da concentração de HDL-colesterol. Transferência de lípides para HDL, mediada por proteínas de transferência CETP e PLTP, é uma etapa importante no transporte reverso de colesterol e metabolismo de HDL.,Desenvolvemos um ensaio in vitro para avaliar as transferências de lípides para a HDL, mostrando que esse fenômeno é alterado em várias condições, como na doença arterial coronária, no diabetes mellitus e pelo estilo de vida sedentário. Recentemente, tem sido descrito que a HDL transporta pequenos RNAs não codificadores de proteína, os chamados microRNAs (miRNAs). Alguns miRNAs foram descritos como reguladores críticos do metabolismo das lipoproteínas. O objetivo deste estudo foi comparar lípides plasmáticos, transferência lipídica para HDL, perfil inflamatório, miRNAs relacionados ao metabolismo de lipoproteínas obtidos de pacientes com IC e de pacientes sem IC (sem-IC). Métodos: Quarenta e oito pacientes com IC foram avaliados, 25 em classe funcional NYHA I e II (IC-I/II) e 23 em NYHA III e IV (IC-III/IV), bem como 50 pacientes sem-IC pareados por gênero e idade. Todos os pacientes com IC apresentavam uma fração de ejeção <=40%. Foram determinadas as concentrações plasmáticas de CETP, LCAT, LDL oxidada (LDLox) e atividade de paraoxonase 1 (PON-1). Transferências de lípides para a HDL foi avaliada a partir da incubação de uma nanopartícula artificial com plasma total. A expressão de miRNAs circulantes envolvidos no metabolismo das lipoproteínas também foi analisada. Resultados: Os níveis de colesterol total, LDL e HDL e triglicérides não diferiram entre os três grupos. A concentração da apolipoproteína A-I foi menor no grupo IC-I/II em comparação ao grupo sem-IC (125±23 versus 142±19; p < 0,05), enquanto que a concentração da apolipoproteína B foi menor em ICIII/ IV comparado ao sem-IC (81±35 versus 114±40; p < 0,001). A transferência de colesterol esterificado (5,44±1,76 versus 6,26±0,85), fosfolípides (19,05±2,5 versus 20,21±1,45) e de triglicérides (6,29±2,05 versus 7,40±1,47) foi menor no grupo IC-III/IV do que no grupo sem-IC (p < 0,05). No entanto, não houve diferença nas transferências entre IC-I/II e sem-IC. A concentração de LDLox foi menor em ambos os grupos com IC comparados ao sem-IC (p < 0,0001). A massa de CETP foi menor em IC-III/IV do que em IC-I/II (2,77±1,3 versus 3,78±1,3; p=0,021). A concentração de LCAT e a atividade de PON-1 não foram diferentes entre os grupos. A análise da expressão dos miRNAs circulantes miR-33a, miR-144, miR-185, miR-125, miR-758, miR-26a, miR- 106b, miR-122 e miR-30c, mostrou-se significantemente aumentada nos indivíduos com IC em comparação aos indivíduos sem-IC, ao passo que o miR- 10b foi o único encontrado diminuído na IC comparado com indivíduos sem-IC (p=0,007). Conclusão: Em pacientes com IC mais severa e sintomática da IC, o processo de transferência de lípides para a HDL está deficiente, bem como alguns dos mecanismos que o regulam, e possivelmente estas alterações influenciem no transporte reverso do colesterol e nas funções protetoras da HDL desses pacientes / Background: World Health Organization estimated that there were twentythree million subjects worldwide suffering from heart failure (HF) in 2015, with mortality rates equivalent to those of cancer. Higher HDL-cholesterol levels have been associated with longer survival in HF. It is now consensual that the various protective functions of HDL should be explored beyond HDLcholesterol. Transfer of lipids to HDL, mediated by transfer proteins CETP and PLTP, is an important step in reverse cholesterol transport and HDL metabolism. Previously, we developed an in vitro assay to test those lipid transfers and showed that transfer of cholesterol to HDL is altered in several conditions, such as coronary artery disease (CAD), diabetes and sedentary lifestyle. Recently, HDL transports small non-coding RNA molecule, called micro RNAs (miRNAs). Some miRNA are critical regulators of lipoprotein metabolism. The aim of this study was compare plasma lipids, lipid transfers to HDL, inflammatory profile, miRNAs related to plasma lipids from patients with HF with those from patients with without HF (non-HF). Methods: Forty-eight HF patients were studied, 25 with functional class NYHA I and II (HF I/II) and 23 with NYHA III and IV (HF III/IV), as well as 50 non-HF patients matched for gender, age and BMI. All HF had ejection fraction <= 40%. CETP, LCAT, oxidized LDL (oxLDL) and paraoxonase 1 (PON-1) activity were determined. Transfers of lipids from a donor artificial nanoparticle to HDL was determined by an in vitro assay in which the emulsion was incubated with whole plasma. Expression of circulating miRNAs involved in cholesterol metabolism was also analyzed. Results: Total, LDL and HDL cholesterol and triglycerides did not differ among the 3 groups. Apolipoprotein A-I was lower in NYHA I/II group compared to non- HF (125±23 versus 142±19; p < 0.05) and apo B was lower in NYHA III/IV group compared to non-HF (81±35 versus 114±40, p < 0.001). The transfer of esterified cholesterol (5.44±1.76 versus 6.26±0.85), phospholipids (19.05±2.5 versus 20.21±1.45) and of triglycerides (6.29±2.05 versus 7.40±1.47) to HDL was lower in HF-III/IV than in non-HF (p < 0.05), but lipid transfers were not different between HF-I/II and non-HF. oxLDL was lower in both HF groups compared to non-HF (p < 0.0001). CETP mass was lower in HF-III/IV than in HF-I/II (2.77±1.3 versus 3.78±1.3; p=0.021). LCAT and PON-1 activity was not different among the groups. Regarding to miRNA, miR-33a, miR-144, miR-185, miR-125, miR- 758, miR-26a, miR-106b, miR-122 e miR-30c were significantly increased in HF compared to non-HF subjects, whereas miR-10b was the only one found to be decreased in HF compared to non-HF subjects (p=0.007). Conclusion: In patients with the more severe and symptomatic HF, the lipid transfer to HDL is deficient, as well as some mechanisms that regulate it, and possibly these changes influence reverse cholesterol transport and the protective functions of HDL in these patients
|
95 |
Effect of phytoestrogens on low-density- lipoprotein receptor and apolipoprotein A-I expression in HepG2 cells.January 2005 (has links)
Yuen Yee Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 108-125). / Abstracts in English and Chinese. / TITLE PAGE --- p.1 / ACKNOWLEGDEMENTS --- p.2 / ABSTRACT --- p.3 / 摘要 --- p.5 / table of contents --- p.7 / list of figures and tables --- p.13 / CHAPTER 1 GENERAL INTRODUCTION --- p.16 / Chapter 1.1 --- role of PHYTOESTROGENS in soy and red WINE the PREVENTION OF CARDIOVASCULAR DISEASES (CVD) --- p.17 / Chapter 1.1.1 --- INTRoduction and Classification of Phytoestrogens --- p.17 / Chapter 1.1.2 --- estrogenic1ty of phytoestrogens and theIr abundancesin Plasma --- p.18 / Chapter 1.1.3 --- phytoestrogens as one of the active components In cvd Protection --- p.21 / Chapter 1.1.4 --- effects of Phytoestrogens on LDL Receptor and Apolipoprotein A-1 --- p.22 / Chapter 1.2 --- role of estrogen receptors (ers) in gene regulation --- p.24 / Chapter 1.2.1 --- "structure, Classification and tissue distribution of ERS" --- p.24 / Chapter 1.2.2 --- ligands for ERS --- p.25 / Chapter 1.2.3 --- mechaniSMS OF LIgands-ERS complex in GENE regulation --- p.27 / Chapter 1.2.4 --- ligand-independent ER activation --- p.28 / Chapter 1.3 --- aims and scopes of investigation --- p.29 / Chapter CHAPTER 2 --- MATERIALS AND METHODS --- p.30 / Chapter 2.1 --- chemicals and materials --- p.30 / Chapter 2.1.1 --- Chemicals --- p.30 / Chapter 2.1.2 --- Plasmids --- p.30 / Chapter 2.2 --- mammalian cell culture maintainence --- p.30 / Chapter 2.2.1 --- Maintenance of Cells --- p.31 / Chapter 2.2.2 --- Preparation of Cell Stock --- p.31 / Chapter 2.2.3 --- Cell Recovery from Liquid Nitrogen Stock --- p.31 / Chapter 2.3 --- manipulation of dna --- p.31 / Chapter 2.3.1 --- isolation of HEPG2 cells genonmic DNA --- p.31 / Chapter 2.3.2 --- separation and purification of dna from agarose gel --- p.31 / Chapter 2.3.3 --- Restriction digestionof DNA --- p.32 / Chapter 2.3.4 --- Ligation of DNA Fragments --- p.32 / Chapter 2.3.5 --- Transformation of --- p.32 / Chapter 2.3.6 --- Small Scale Plasmids Purification from DH5a --- p.32 / Chapter 2.4 --- construction of expression and reporter plasmids --- p.33 / Chapter 2.4.1 --- Construction of Estrogen Receptorα (Erα) Expression Vectors --- p.33 / Chapter 2.4.2 --- construction of reporter vectors of LDLR promoter and the Respective Mutants --- p.33 / Chapter 2.4.3 --- Construction of Reporter Vectors of APOAI Promoter and the Respective Mutants --- p.33 / Chapter 2.5 --- determination of promoter transcrtiption activities --- p.34 / Chapter 2.5.1 --- Transient Transfection of Cell with ERa Expression Vector and Promoter Reporter using Lipofectamine PLUS Reagent --- p.34 / Chapter 2.5.2 --- Dual Luciferase Assay --- p.34 / Chapter 2.6 --- semi-quantitative and quantitative rt-pcr assay --- p.34 / Chapter 2.6.1 --- Transient transfection of Cell with ERa Expression Vector Using Lipofectamine PLUS Reagent --- p.34 / Chapter 2.6.2 --- "Isolation of RNA using TRIzol® Reagent (Life Technology, USA)" --- p.35 / Chapter 2.6.3 --- Quantitation of RNA --- p.35 / Chapter 2.6.4 --- First Strand cDNA Synthesis --- p.35 / Chapter 2.6.5 --- Sem卜Quantitative PCR Reactions --- p.35 / Chapter 2.6.6 --- Quantitative PCR Reactions --- p.36 / Chapter 2.7 --- western blotting analysis --- p.36 / Chapter 2.8 --- statistical methods --- p.36 / Chapter CHAPTER 3 --- REGULATION BY PHYSIOLOGICAL LEVEL OF 17B-ESTRADIOL ON APOLIPOPROTEIN A-I AND LOW-DENSITY- LIPOPROTEIN RECEPTOR IN HEPG2 CELLS --- p.37 / Chapter 3.1 --- introduction --- p.37 / Chapter 3.2 --- results --- p.39 / Chapter 3.2.1 --- Determination of transient transfection functionality of estrogen receptors in hepg2 cells --- p.39 / Chapter 3.2.2 --- Effect of 17β-Estradiolon LDLR promoter transcription activity --- p.39 / Chapter 3.2.3 --- Effect of 17β-Estradiol on apoai promoter transcription activity --- p.40 / Chapter 3.2 --- discussion --- p.47 / Chapter CHAPTER 4 --- SOY ISOFLAVONES AND RESVERATROL DISPLAY DIFFERENT MECHANISM IN THE UP-REGULATION OF LOVV-DENSITY-LIPOPROTEIN RECEPTOR IN HEPG2 CELLS --- p.49 / Chapter 4.1 --- introduction --- p.49 / Chapter 4.2 --- results --- p.54 / Chapter 4.2.1 --- Association of ERα and isoflavones or resveratrol on LDLR promoter transcription activity --- p.54 / Chapter 4.2.2 --- Association of ERβ and isoflavones or resveratrol on LDLR promoter transcription activity --- p.54 / Chapter 4.2.3 --- "Role of MAP Kinase, PKA and PKC in isoflavones and resveratrol induced LDLR promoter transcription" --- p.55 / Chapter 4.2.4 --- Identification of promoter regions responsible for induction of LDLR transcription by isoflavones in the presence OF ERα --- p.55 / Chapter 4.2.5 --- Identification of promoter regions responsible for induction of LDLR TRANSCRIPTION BY resveratrol IN THE ABSENCE OF ERα --- p.56 / Chapter 4.3 --- DISCUSSION --- p.75 / Chapter CHAPTER 5 --- SOY ISOFLAVONES AND RESVERATROL UP-REGULATE APOLIPOPROTEIN A-I SIMILAR TO 17B-ESTRADIOL IN HEPG2 CELLS --- p.80 / Chapter 5.1 --- INTRODUCTION --- p.80 / Chapter 5.2 --- RESULTS --- p.84 / Chapter 5.2.1 --- Association of ERα phytoestrogens on APCAI gene expression --- p.84 / Chapter 5.2.2 --- Association of ERβ and isoflavones or resveratrol on APOAI promoter transcription activity --- p.85 / Chapter 5.2.3 --- "Role of MAP Kinase, PKA and PKC in isoflavones and resveratrol in APOAI promoter transcription in the presence of ERα" --- p.85 / Chapter 5.2.4 --- Identification of promoter regions responsible for induction of APOAI transcription by isoflavones and resveratrol in the presence of ERα --- p.85 / Chapter 5.3 --- DISCUSSION --- p.100 / Chapter CHAPTER 6 --- GENERAL DISCUSSION --- p.103 / Chapter CHAPTER 7 --- SUMMARY --- p.106 / BIBLIOGRAPHY --- p.108 / APPENDIX 1 ABBREVIATIONS --- p.126 / APPENDIX 2 MATERIALS AND METHODS --- p.129 / APPENDIX 3 PRIMER LISTS --- p.145 / APPENDIX 4 REAGENTS AND BUFFERS --- p.147
|
96 |
The role of fibroblast growth factor-23 in chronic kidney disease-mineral and bone disorderMirza, Majd A. I. January 2010 (has links)
Fibroblast growth factor-23 (FGF23) was initially identified as the causative factor of autosomal dominant hypophosphatemic rickets. Further studies confirmed that FGF23 is predominantly expressed in the osteocytes and osteoblasts of bone and that circulating FGF23 acts on the kidney to inhibit renal phosphate reabsorption and 1,25(OH)2D3 hydroxylation. With the progression of chronic kidney disease (CKD), the kidneys become insufficient to maintain a normal systemic mineral homeostasis, resulting in various abnormalities of bone and mineral metabolism, generally referred to as Chronic Kidney Disease – Mineral and Bone Disorders (CKD-MBD). FGF23 increases early in the course of CKD in order to maintain normal serum phosphate levels; long before a significant increase in serum phosphate can be detected. Recent studies suggest that increased FGF23 levels are associated with progression of CKD, mortality, and the development of refractory secondary hyperparathyroidism. Because FGF23 is the very earliest marker of CKD-MBD, it is of particular interest to evaluate the relation between FGF23 and CKD-MBD abnormalities, in the setting of early CKD and also in individuals with normal renal function. In the present work, we show that FGF23 is linked to several dynamic measurements of vascular function, including endothelial dysfunction, arterial stiffness, and atherosclerosis. FGF23 is also positively associated with left ventricular mass index and an increased risk of having left ventricular hypertrophy. All associations were independent of serum phosphate and were strengthened in subjects with diminished renal function. Furthermore, we found significant evidence for an association between higher FGF23 and increased fat mass and dyslipidemia, which could represent a novel pathway linking FGF23 to cardiovascular disease. Finally, we show that FGF23 is a significant predictor of future fracture risk. Although these associations could be reflecting the increased risk associated with hyperphosphatemia and calcitriol deficiency, current evidence points towards FGF23 being more than an innocent bystander. At the very least, FGF23 holds promise of being a bio-marker of cardiovascular status and phosphate-related toxicity both in CKD and in the general population, and might be a therapeutic target that could improve the fatal prognosis in CKD patients.
|
97 |
Papel dos lípides plasmáticos e fatores pró-inflamatórios na fisiopatologia da insuficiência cardíaca / Role of plasma lipids and pro inflammatory factors in the patho physiology of heart failureAna Elisa Marabini Martinelli 19 May 2017 (has links)
Introdução: A Organização Mundial da Saúde estimou em 2015 que 23 milhões de pessoas em todo o mundo sofrem de insuficiência cardíaca (IC), com taxas de mortalidade equivalentes às do câncer. Níveis mais elevados de HDL-colesterol têm sido associados com maior sobrevivência na IC. É consensual que as várias funções protetoras da HDL devem ser exploradas além da concentração de HDL-colesterol. Transferência de lípides para HDL, mediada por proteínas de transferência CETP e PLTP, é uma etapa importante no transporte reverso de colesterol e metabolismo de HDL.,Desenvolvemos um ensaio in vitro para avaliar as transferências de lípides para a HDL, mostrando que esse fenômeno é alterado em várias condições, como na doença arterial coronária, no diabetes mellitus e pelo estilo de vida sedentário. Recentemente, tem sido descrito que a HDL transporta pequenos RNAs não codificadores de proteína, os chamados microRNAs (miRNAs). Alguns miRNAs foram descritos como reguladores críticos do metabolismo das lipoproteínas. O objetivo deste estudo foi comparar lípides plasmáticos, transferência lipídica para HDL, perfil inflamatório, miRNAs relacionados ao metabolismo de lipoproteínas obtidos de pacientes com IC e de pacientes sem IC (sem-IC). Métodos: Quarenta e oito pacientes com IC foram avaliados, 25 em classe funcional NYHA I e II (IC-I/II) e 23 em NYHA III e IV (IC-III/IV), bem como 50 pacientes sem-IC pareados por gênero e idade. Todos os pacientes com IC apresentavam uma fração de ejeção <=40%. Foram determinadas as concentrações plasmáticas de CETP, LCAT, LDL oxidada (LDLox) e atividade de paraoxonase 1 (PON-1). Transferências de lípides para a HDL foi avaliada a partir da incubação de uma nanopartícula artificial com plasma total. A expressão de miRNAs circulantes envolvidos no metabolismo das lipoproteínas também foi analisada. Resultados: Os níveis de colesterol total, LDL e HDL e triglicérides não diferiram entre os três grupos. A concentração da apolipoproteína A-I foi menor no grupo IC-I/II em comparação ao grupo sem-IC (125±23 versus 142±19; p < 0,05), enquanto que a concentração da apolipoproteína B foi menor em ICIII/ IV comparado ao sem-IC (81±35 versus 114±40; p < 0,001). A transferência de colesterol esterificado (5,44±1,76 versus 6,26±0,85), fosfolípides (19,05±2,5 versus 20,21±1,45) e de triglicérides (6,29±2,05 versus 7,40±1,47) foi menor no grupo IC-III/IV do que no grupo sem-IC (p < 0,05). No entanto, não houve diferença nas transferências entre IC-I/II e sem-IC. A concentração de LDLox foi menor em ambos os grupos com IC comparados ao sem-IC (p < 0,0001). A massa de CETP foi menor em IC-III/IV do que em IC-I/II (2,77±1,3 versus 3,78±1,3; p=0,021). A concentração de LCAT e a atividade de PON-1 não foram diferentes entre os grupos. A análise da expressão dos miRNAs circulantes miR-33a, miR-144, miR-185, miR-125, miR-758, miR-26a, miR- 106b, miR-122 e miR-30c, mostrou-se significantemente aumentada nos indivíduos com IC em comparação aos indivíduos sem-IC, ao passo que o miR- 10b foi o único encontrado diminuído na IC comparado com indivíduos sem-IC (p=0,007). Conclusão: Em pacientes com IC mais severa e sintomática da IC, o processo de transferência de lípides para a HDL está deficiente, bem como alguns dos mecanismos que o regulam, e possivelmente estas alterações influenciem no transporte reverso do colesterol e nas funções protetoras da HDL desses pacientes / Background: World Health Organization estimated that there were twentythree million subjects worldwide suffering from heart failure (HF) in 2015, with mortality rates equivalent to those of cancer. Higher HDL-cholesterol levels have been associated with longer survival in HF. It is now consensual that the various protective functions of HDL should be explored beyond HDLcholesterol. Transfer of lipids to HDL, mediated by transfer proteins CETP and PLTP, is an important step in reverse cholesterol transport and HDL metabolism. Previously, we developed an in vitro assay to test those lipid transfers and showed that transfer of cholesterol to HDL is altered in several conditions, such as coronary artery disease (CAD), diabetes and sedentary lifestyle. Recently, HDL transports small non-coding RNA molecule, called micro RNAs (miRNAs). Some miRNA are critical regulators of lipoprotein metabolism. The aim of this study was compare plasma lipids, lipid transfers to HDL, inflammatory profile, miRNAs related to plasma lipids from patients with HF with those from patients with without HF (non-HF). Methods: Forty-eight HF patients were studied, 25 with functional class NYHA I and II (HF I/II) and 23 with NYHA III and IV (HF III/IV), as well as 50 non-HF patients matched for gender, age and BMI. All HF had ejection fraction <= 40%. CETP, LCAT, oxidized LDL (oxLDL) and paraoxonase 1 (PON-1) activity were determined. Transfers of lipids from a donor artificial nanoparticle to HDL was determined by an in vitro assay in which the emulsion was incubated with whole plasma. Expression of circulating miRNAs involved in cholesterol metabolism was also analyzed. Results: Total, LDL and HDL cholesterol and triglycerides did not differ among the 3 groups. Apolipoprotein A-I was lower in NYHA I/II group compared to non- HF (125±23 versus 142±19; p < 0.05) and apo B was lower in NYHA III/IV group compared to non-HF (81±35 versus 114±40, p < 0.001). The transfer of esterified cholesterol (5.44±1.76 versus 6.26±0.85), phospholipids (19.05±2.5 versus 20.21±1.45) and of triglycerides (6.29±2.05 versus 7.40±1.47) to HDL was lower in HF-III/IV than in non-HF (p < 0.05), but lipid transfers were not different between HF-I/II and non-HF. oxLDL was lower in both HF groups compared to non-HF (p < 0.0001). CETP mass was lower in HF-III/IV than in HF-I/II (2.77±1.3 versus 3.78±1.3; p=0.021). LCAT and PON-1 activity was not different among the groups. Regarding to miRNA, miR-33a, miR-144, miR-185, miR-125, miR- 758, miR-26a, miR-106b, miR-122 e miR-30c were significantly increased in HF compared to non-HF subjects, whereas miR-10b was the only one found to be decreased in HF compared to non-HF subjects (p=0.007). Conclusion: In patients with the more severe and symptomatic HF, the lipid transfer to HDL is deficient, as well as some mechanisms that regulate it, and possibly these changes influence reverse cholesterol transport and the protective functions of HDL in these patients
|
Page generated in 0.0732 seconds