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Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 4 uppsatser.

published_or_final_version / Medicine / Master / Master of Philosophy

Li Tin Wai Olive. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 191-217). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.II / ABSTRACT --- p.III / 中文摘要 --- p.IX / PUBLICATIONS --- p.XIV / TABLE OF CONTENTS --- p.XV / LIST OF ABBREVIATIONS --- p.XXI / LIST OF FIGURES AND TABLES --- p.XXIII / Chapter CHAPTER 1. --- INTRODUCTION --- p.1 / Chapter CHAPTER 2. --- LITERATURE REVIEW --- p.7 / Chapter 2.1. --- Cardiovascular disease --- p.7 / Chapter 2.1.1. --- Introduction --- p.7 / Chapter 2.1.2. --- Atherosclerosis --- p.7 / Chapter 2.1.3. --- Cellular and molecular deregulation in early atherosclerosis --- p.10 / Chapter 2.1.3.1. --- Introduction --- p.10 / Chapter 2.1.3.2. --- Endothelial dysfunction --- p.11 / Chapter 2.1.3.3. --- Nitric oxide --- p.12 / Chapter 2.1.3.4. --- Adhesion molecules and the early events of atherogenesis --- p.13 / Chapter 2.1.3.4.1. --- Introduction --- p.13 / Chapter 2.1.3.4.2. --- Intracellular adhesion molecule-1 --- p.15 / Chapter 2.1.3.4.3. --- Nuclear factor kappa B --- p.18 / Chapter 2.1.3.5. --- Summary --- p.19 / Chapter 2.2. --- Nitric oxide in molecular vascular biology --- p.20 / Chapter 2.2.1. --- Introduction --- p.20 / Chapter 2.2.2. --- Nitric oxide synthase --- p.21 / Chapter 2.2.2.1. --- Introduction --- p.21 / Chapter 2.2.2.2. --- Endothelial nitric oxide synthase --- p.24 / Chapter 2.2.2.3. --- Inducible nitric oxide synthase --- p.25 / Chapter 2.2.2.4. --- Nitric oxide concentration dependent effector pathways --- p.26 / Chapter 2.2.3. --- Nitric oxide and its regulation in vascular events --- p.28 / Chapter 2.2.3.1. --- Introduction --- p.28 / Chapter 2.2.3.2. --- Regulation of vascular tone --- p.30 / Chapter 2.2.3.3. --- "Regulation of platelet adhesion, activation and aggregation" --- p.32 / Chapter 2.2.3.4. --- Regulation of endothelial adhesiveness and leukocyte adhesion - Anti-adhesive effect of nitric oxide --- p.32 / Chapter 2.2.3.5. --- "Regulation of vascular smooth muscle growth, migration and proliferation" --- p.33 / Chapter 2.2.3.6. --- Antioxidative effect of nitric oxide --- p.34 / Chapter 2.2.3.7. --- Regulation of endothelial apoptosis --- p.35 / Chapter 2.2.3.8. --- Nitric oxide and its relationship with other risk factors --- p.36 / Chapter 2.3. --- "Menopause, cardiovascular diseases and Traditional Chinese Medicine" --- p.37 / Chapter 2.3.1. --- Traditional Chinese Medicine and menopause --- p.37 / Chapter 2.3.2. --- Dang Gui Buxue Tang --- p.38 / Chapter 2.3.3. --- Danggui --- p.39 / Chapter 2.3.3.1. --- Botanic origins --- p.39 / Chapter 2.3.3.2. --- Usage --- p.39 / Chapter 2.3.4. --- Huangqi --- p.40 / Chapter 2.3.4.1. --- Botanic origins --- p.40 / Chapter 2.3.4.2. --- Usage --- p.40 / Chapter 2.3.5. --- Modern scientific research --- p.41 / Chapter 2.3.5.1. --- General cardioprotective role --- p.41 / Chapter 2.3.5.2. --- Vascular tone modulation --- p.42 / Chapter 2.3.5.3. --- Haemostasis --- p.42 / Chapter 2.3.5.4. --- Endothelial cell --- p.43 / Chapter 2.3.5.4.1. --- Nitric oxide pathway --- p.43 / Chapter 2.3.5.4.1.1. --- Direct alteration of nitric oxide secretion --- p.43 / Chapter 2.3.5.4.1.2. --- Alteration of Nitric oxide synthase expression or activity --- p.43 / Chapter 2.3.5.4.2. --- Alteration of adhesion molecule expression --- p.44 / Chapter 2.3.5.4.3. --- Alteration of adhesion molecule expression as an effect of nitric oxide secretion --- p.45 / Chapter 2.3.5.5. --- Antioxidant effect --- p.45 / Chapter 2.3.5.6. --- Estrogenicity of DBT --- p.46 / Chapter 2.4. --- Research plan --- p.47 / Chapter 2.4.1. --- Formulation of research hypotheses --- p.47 / Chapter 2.4.1.1. --- Hypotheses --- p.50 / Chapter 2.4.2. --- Plan of study --- p.50 / Chapter 2.4.2.1. --- Dang Gui Buxue Tang extraction and standardization of content --- p.50 / Chapter 2.4.2.2. --- Cell model development --- p.52 / Chapter 2.4.2.3. --- Experimental studies --- p.54 / Chapter 2.4.2.4. --- eNOS activity determination - the nitric oxide metabolite assay --- p.56 / Chapter 2.4.2.5. --- Endotoxin contamination in DBT --- p.57 / Chapter 2.4.3. --- Sample size and statistical analysis --- p.59 / Chapter CHAPTER 3. --- MATERIALS AND METHODS --- p.62 / Chapter 3.1. --- Dang Gui Buxue Tang extraction and content standardization --- p.62 / Chapter 3.1.1. --- Plant materials --- p.62 / Chapter 3.1.2. --- DBT authentication --- p.62 / Chapter 3.1.3. --- DBT processing prior to extraction --- p.63 / Chapter 3.1.4. --- DBT extraction --- p.63 / Chapter 3.1.5. --- Quantitative standardization of DBT markers by High Pressure Liquid Chromatography --- p.66 / Chapter 3.1.5.1. --- DBT markers: standard preparation --- p.66 / Chapter 3.1.5.2. --- Sample preparation --- p.67 / Chapter 3.1.5.3. --- Quantitative analysis of DBT constituents by HPLC --- p.67 / Chapter 3.1.6. --- DBT polysaccharide standardization --- p.68 / Chapter 3.1.6.1. --- Glucose standard preparation --- p.68 / Chapter 3.1.6.2. --- Sample preparation --- p.68 / Chapter 3.1.6.3. --- Quantitative determination of polysaccharide by Phenol-Sulfuric acid colorimetric assay --- p.68 / Chapter 3.1.7. --- DBT endotoxin contamination determination --- p.69 / Chapter 3.1.7.1. --- "Positive, negative and inhibition controls" --- p.69 / Chapter 3.1.7.2. --- Qualitative determination of sample endotoxin --- p.70 / Chapter 3.2. --- Cell culture --- p.70 / Chapter 3.2.1. --- Characterization of cultured cells --- p.72 / Chapter 3.2.2. --- Passage --- p.73 / Chapter 3.3. --- DBT treatment --- p.73 / Chapter 3.3.1. --- Solvent system of DBT treatment --- p.73 / Chapter 3.3.2. --- Dosage and duration of DBT treatment --- p.74 / Chapter 3.3.3. --- Positive and negative controls --- p.74 / Chapter 3.4. --- MTT-based cytotoxicity assay --- p.75 / Chapter 3.5. --- Reverse transcriptase- polymerase chain reaction --- p.76 / Chapter 3.5.1. --- Sample preparation --- p.76 / Chapter 3.5.1.1. --- Total RNA isolation --- p.76 / Chapter 3.5.1.2. --- DNase treatment --- p.77 / Chapter 3.5.1.3. --- RNAethanol precipitation --- p.78 / Chapter 3.5.1.4. --- Complementary DNA synthesis --- p.78 / Chapter 3.5.2. --- Polymerase chain reaction --- p.79 / Chapter 3.5.2.1. --- Polymerase chain reaction conditions --- p.79 / Chapter 3.5.2.2. --- Primers --- p.79 / Chapter 3.5.3. --- Visualization of the PCR products --- p.81 / Chapter 3.5.3.1. --- Gel electrophoresis --- p.81 / Chapter 3.5.3.2. --- Gel Doc software --- p.82 / Chapter 3.5.3.3. --- Densitometry --- p.82 / Chapter 3.5.4. --- Real time RT-PCR --- p.82 / Chapter 3.6. --- Quantitative Immunocytochemical studies --- p.84 / Chapter 3.6.1. --- Coverslip preparation --- p.84 / Chapter 3.6.2. --- Sample preparation --- p.84 / Chapter 3.6.3. --- Immunocytochemical staining preparation --- p.85 / Chapter 3.6.3.1. --- "Immunocytochemical staining for vWF, α-actin, iNOS, ICAM-1, NF-kB using DAKO catalyzed signal amplification (CSA) system (anti-mouse)" --- p.86 / Chapter 3.6.3.2. --- Immunocytochemical staining for eNOS using Santa Cruz immunoCruz staining system (anti-goat) --- p.87 / Chapter 3.6.4. --- Counterstaining and mounting --- p.88 / Chapter 3.6.5. --- Result interpretation --- p.89 / Chapter 3.6.5.1. --- Microscopy and digital image capture --- p.89 / Chapter 3.6.5.2. --- Determination of Image (file) Energy --- p.89 / Chapter 3.7. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.90 / Chapter 3.7.1. --- Sample preparation --- p.90 / Chapter 3.7.2. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.91 / Chapter CHAPTER 4. --- RESULTS --- p.93 / Chapter 4.1. --- Dang Gui Buxue Tang extraction and standardization of content --- p.93 / Chapter 4.1.1. --- DBT extraction - general data --- p.93 / Chapter 4.1.2. --- DBT polysaccharide standardization --- p.97 / Chapter 4.1.3. --- DBT marker standardization --- p.101 / Chapter 4.1.4. --- DBT endotoxin contamination determination --- p.104 / Chapter 4.2. --- Cell model development --- p.108 / Chapter 4.2.1. --- Endothelial morphology --- p.108 / Chapter 4.2.2. --- Immunocytochemistiy --- p.108 / Chapter 4.2.3. --- MTT cytotoxicity assay --- p.110 / Chapter 4.3. --- Study 1 --- p.112 / Chapter 4.3.1. --- Immunocytochemistry (Hypothesis 1) --- p.112 / Chapter 4.3.2. --- RT-PCR (Hypothesis 1) --- p.117 / Chapter 4.3.3. --- Real time RT-PCR (Hypothesis 1) --- p.121 / Chapter 4.3.4. --- Immunocytochemistry (Hypothesis 2) --- p.125 / Chapter 4.3.5. --- RT-PCR (Hypothesis 2) --- p.128 / Chapter 4.3.6. --- Total Nitrite/Nitrate quantitative colorimetric assay --- p.131 / Chapter 4.4. --- Study 2 --- p.133 / Chapter 4.4.1. --- Immunocytochemistry --- p.133 / Chapter 4.5. --- Study 3 --- p.138 / Chapter 4.5.1. --- Immunocytochemistry --- p.138 / Chapter 4.5.2. --- RT-PCR --- p.141 / Chapter 4.5.3. --- Real time RT-PCR --- p.145 / Chapter 4.6. --- Endotoxin contamination in DBT --- p.149 / Chapter 4.6.1. --- Effects of endotoxin on eNOS --- p.149 / Chapter 4.6.2. --- Immunocytochemistry on immunostained endothelial cells --- p.151 / Chapter 4.6.3. --- Effects of endotoxin on iNOS --- p.153 / Chapter 4.6.4. --- Effect of endotoxin on NF-kB --- p.157 / Chapter 4.6.5. --- Effects of endotoxin on ICAM-1 --- p.160 / Chapter CHAPTER 5. --- DISCUSSION --- p.165 / Chapter 5.1. --- DBT extraction and standardization of content --- p.165 / Chapter 5.1.1. --- Optimal DBT extraction conditions --- p.165 / Chapter 5.1.2. --- Evidence to support formulae usage --- p.166 / Chapter 5.1.3. --- Limitation of the methodology used --- p.166 / Chapter 5.2. --- Cell model development --- p.167 / Chapter 5.2.1. --- Choice of DBT concentration range in the study --- p.167 / Chapter 5.2.1.1. --- Choice of concentration range in consideration of endotoxin contamination --- p.167 / Chapter 5.2.1.2. --- Choice of concentration range in consideration of DBT's cytotoxicity effects --- p.168 / Chapter 5.2.1.3. --- Choice of concentration range in consideration of prevous studies --- p.168 / Chapter 5.3. --- Study 1 --- p.169 / Chapter 5.3.1. --- Action of DBT on eNOS expression --- p.169 / Chapter 5.3.2. --- Action of DBT on iNOS expression --- p.170 / Chapter 5.3.3. --- Action of DBT on Nitric oxide metabolite assay --- p.171 / Chapter 5.3.3.1. --- Result interpretation with rejected hypothesis 2 --- p.171 / Chapter 5.3.3.2. --- Assay limitations and improvements --- p.171 / Chapter 5.4. --- Study 2 --- p.172 / Chapter 5.4.1. --- Action of DBT on NF-kB expression --- p.172 / Chapter 5.4.2. --- Assay limitations and improvements --- p.173 / Chapter 5.5. --- Study 3 --- p.174 / Chapter 5.5.1. --- Action of DBT on ICAM-1 expression --- p.174 / Chapter 5.6. --- Endotoxin contamination in DBT --- p.175 / Chapter 5.6.1. --- Action of endotoxin contamination in DBT on various markers --- p.175 / Chapter 5.6:2. --- Experimental limitation --- p.176 / Chapter 5.6.3. --- Endotoxin removal --- p.177 / Chapter 5.6.3.1. --- Introduction --- p.177 / Chapter 5.6.3.2. --- Endotoxin removal methodologies suitable for herbal use --- p.179 / Chapter 5.7. --- Action of DBT on angiogenesis stimulation --- p.181 / Chapter 5.7.1. --- Evidence for DBT's proangiogenic effects from various studies --- p.181 / Chapter 5.7.2. --- Influence of endotoxin contamination on angiogenesis stimulation --- p.182 / Chapter 5.7.3. --- Assay limitations and future developments --- p.183 / Chapter CHAPTER 6. --- GENERAL DISCUSSION AND SUMMARY --- p.186 / Chapter CHAPTER 7. --- REFERENCES --- p.191

La artritis reumatoide (AR) es una enfermedad inflamatoria cr_nica que se ha asociado a un incremento de enfermedad cardiovascular (ECV). La causa de este elevado riesgo de ECV no se conoce, se ha sugerido que la actividad inflamatoria de la AR pudiera dar lugar a una aterog_nesis acelerada. La arteriosclerosis es la causa subyacente de la ECV y se caracteriza por una acumulaci_n de lipoprote_nas apo B, matriz extracelular, c_lulas, y por un aumento de la oxidaci_n lip_dica en la _ntima de la pared arterial. Estudios experimentales sugieren que la oxidaci_n lip_dica y la inflamaci_n juegan un papel principal en la arteriosclerosis y sus consecuencias cl_nicas. Marcadores de inflamaci_n como la proteina C reactiva (PCR), las mol_culas de adhesi_n o la fosfolipasa A2 secretora del grupo IIA (sPLA2-IIA) se han relacionado con un mayor riesgo de ECV. Adem_s, la sPLA2-IIA se ha encontrado en lesiones ateroscler_ticas de arterias humanas.En pacientes con AR se han observado alteraciones en el perfil lip_dico caracterizadas por una disminuci_n en las concentraciones plasm_ticas de colesterol total y de lipoprote_nas tanto HDL como LDL. Aunque, este perfil lip_dico no implica un mayor riesgo aterog_nico. El objetivo de nuestro estudio fue investigar en pacientes con AR si la actividad inflamatoria de la enfermedad induce cambios cualitativos en las part_culas lipoproteicas mediados por acciones enzim_ticas de la sPLA2-IIA y oxidativas que derivan en lipoprote_nas m_s aterog_nicas, con la finalidad de contribuir a explicar la elevada mortalidad por ECV descrita en estos pacientes.M_todos: Estudiamos en pacientes con AR y en un grupo control: marcadores de inflamaci_n sist_micos, el perfil lip_dico, las subfracciones de la LDL y HDL, la afinidad de la LDL por el glucoaminoglicano (GAG) condroitin 6-sulfato, la susceptibilidad a la oxidaci_n de la LDL y los niveles en plasma de vitaminas A y E.Resultados: Los pacientes con AR (n=31) y el grupo control (n=28) presentaron niveles en plasma similares de colesterol total, triglic_ridos, Apo-A, Apo-B, HDL y VLDL. Los niveles de LDL en plasma fueron m_s bajos en pacientes con AR. Los pacientes con AR presentaron un aumento significativo de los niveles en plasma de sPLA2-IIA, ICAM, PCR, fibrin_geno, IFNg y TNFa en comparaci_n con el grupo control. Los pacientes con AR presentaron niveles de LDL-1 densas y peque_as m_s altos (p<0.05) y m_s bajos de HDL-2 densas (p<0.001) que el grupo control. Adem_s, las LDL de los pacientes con AR presentaron una mayor afinidad por los GAG (Kd 204 ± 22.4 nM Apo B) en comparaci_n con el grupo control (Kd 312 ± 364 nM Apo B) (p<0.05). La Kd-LDL se correlacion_ inversamente con los niveles en plasma de LDL-1 (r=-0.566, p<0.004). En los pacientes con AR encontramos una correlaci_n positiva y significativa entre marcadores de inflamaci_n (PCR, ICAM, sPLA2-IIA) y las LDL-1. Las HDL-2 se correlacionaron negativamenre con la sPLA2-IIA. Los niveles en plasma de vitamina A fueron m_s bajos en pacientes y los de vitamina E similares en ambos grupos. Los par_metros oxidativos, medidos a trav_s de las diferentes fases de formaci_n de dienos conjugados, fueron similares en pacientes y controles. En pacientes con AR encontramos una correlaci_n inversa entre sPLA2-IIA, PCR y las vitaminas antioxidantes, as_ como una correlaci_n positiva entre la Kd-LDL y la lag phase en oxidaci_n de las LDL. Conclusi_n y discusi_n: En pacientes con AR hemos encontrado niveles elevados de LDL densas y peque_as con una alta afinidad por los componentes de la matriz extracelular. La afinidad de las LDL por los GAG se correlacion_ positivamente con los niveles de sPLA2-IIA y con una mayor suceptibilidad a la oxidaci_n de las LDL. Estos marcadores lipoproteicos aterog_nicos sumado a la inflamaci_n cr_nica podr_an contribuir a explicar el aumento de mortalidad por ECV en pacientes con AR. / Rheumatoid arthritis (RA) is a chronic inflammatory disease that has been associated with an increase in cardiovascular diseases (CVD). The cause of increased risk for CVD in patients with RA is unknown. It has been postulated that the chronic inflammation associated with RA could lead to an accelerated atherogenesis. Atherosclerosis, the underlying cause of CVD, is characterized by acumulation of Apo B lipoproteins, extracelular matrix, cells, and by an increase of the lipid peroxidation in the intima of the arterial wall. Experimentals studies data suggest that inflammation and the lipid peroxidation plays a significant role in atherogenesis and its clinical consequences. Plasma levels of inflammatory markers such as C-reactive protein (CRP), solubles adhesion molecules and secretory group phospholipase A2 (sPLA2-IIA) have been associated with a higher risk of CVD. Furthermore, the sPLA2-IIA is present in atherosclerotic lesions of human arteries.Lipid anormalities, such as decreased serum cholesterol and cholesterol levels in lipoproteins (low density (LDL) and high density (HDL) lipoproteins) have been described in patients with RA. However, this lipoprotein profile does not imply a higher atherogenic risk. The aim of our study was to investigate in patients with RA if inflammatory activity of the disease induce qualitatives changes in the lipoproteins particles mediated by enzymatics actions of the sPLA2-IIA and oxidatives that derive in more atherogenic lipoproteins, with the finality of to contribute to an explanation of the high risk of CVD in RA patients.Methods: We studied in RA patients as well as in the control group: Plasma inflammatory markers, lipid profile, the size distribution of plasma lipoprotein subclasses, the binding affinity of LDL to chondroitin 6-sulfate glycosaminoglycan (GAG), the susceptibility of LDL to oxidation and the concentrations of vitamins A and E.Results: RA patients (n=31) and matched controls (n=28) had similar plasma concentrations of cholesterol, triglycerides, Apo B, Apo A-I, VLDL and HDL. RA patients had significantly lower plasma levels of LDL. RA patients had significantly higher plasma levels of sPLA2-IIA, ICAM, CRP, fibrinogen, TNFa, and IFNg compared with controls. RA patients also had significantly higher levels of small, dense LDL-1 (p<0.05) and lower levels of small HDL-2 particles (p<0.001) compared with controls. In addition, LDL from RA patients had a significantly higher affinity (Kd) to GAG (mean ± SD Kd 204 ± 22.4 nM Apo B) than did LDL from control subjects (Kd 312 ± 364 nM Apo B) (p<0.05). This Kd value showed a significant negative correlation with the plasma levels of LDL-1 (r=-0.566, p<0.004). In RA patients, a significant positive correlation was obtained between sPLA2-IIA and CRP, ICAM, and LDL-1. HDL-2 showed a negative correlation with sPLA2-IIA. Plasma levels of vitamin A were lower in patients, and similar levels of vitamin E were observed in both groups. Oxidative variables, measured as the diferent phases of conjugated diene formation, were similar in patients and controls. We found a significant inverse correlation between vitamin A and E, and sPLA2-IIA. We found a positive correlation between the Kd-LDL and the lag phase of LDL oxidation in RA patients.Conclusion and discusion: In patientes with RA, we found elevated levels of small, dense LDL with high affinity for arterial matrix components. The LDL affinity to GAG showed a positive correlation with the plasma levels of sPLA2-IIA and the susceptibility to the oxidation of the LDL. These atherogenic lipoprotein factors combined with the presence of chronic inflammation may contribute to the high CVD related mortality in RA patients.

Las apolipoproteínas más abundantes de HDL son la apoA-I y la apoA-II. La concentración plasmática de apoA-I está inversamente relacionada con el riesgo de enfermedad coronaria y su papel en las HDL es bien conocido. La apoA-I tiene un papel estructural muy importante en HDL, interacciona con receptores de HDL provocando el eflujo de colesterol de membranas celulares y es cofactor de la LCAT. En cambio, el papel que juega la apoA-II en el metabolismo lipoproteico y en el desarrollo de la arteriosclerosis es menos conocido. La línea de ratones transgénicos con más expresión de apoA-II humana (línea 11.1) alimentada con dieta aterogénica desarrolla hiperlipemia combinada, deficiencia de HDL y aumento notable de susceptibilidad a la arteriosclerosis. Los ratones transgénicos de apoA-II humana de la línea 11.1 presentaron un gran aumento del área de tinción para epítopos derivados de oxidación en estas lesiones respecto de los controles. En el estudio de las propiedades antioxidantes de las HDL de los ratones 11.1, éstas presentaron una menor capacidad de protección frente a la oxidación de lipoproteínas con apoB, que las HDL de ratones controles y que los transgénicos 25.3 (baja expresión de apoA-II). Las HDL de los ratones transgénicos 11.1 presentaron una composición alterada con gran cantidad de apoA-II humana, y disminución de apoA-I, PON1 y PAF-AH, que probablemente explican la menor protección frente a la oxidación que proveen estas HDL. Estos cambios en las partículas de HDL no son debidos a cambios en la transcripción de los genes de apoA-I, PON1, PAF-AH, LCAT. Sin embargo, en ensayos in vitro se comprobó que la apoA-II humana es capaz de desplazar la PON1 de la partícula de HDL. La alteración en la capacidad antioxidante de las HDL de transgénicos 11.1 explica, al menos en parte, la susceptibilidad a la arteriosclerosis aumentada en estos animales en dieta aterogénica. En el estudio de la capacidad de estas HDL de realizar transporte reverso de colesterol, los resultados mostraron que, a pesar de la deficiencia parcial de HDL que presentan, los ratones transgénicos 11.1 no mostraron una alteración importante en el ritmo de transporte reverso de colesterol específico de macrófagos, respecto de los ratones controles. Así pues, la susceptibilidad a la arteriosclerosis en ratones transgénicos 11.1 alimentados con dieta aterogénica, no parece ser atribuible a una disminución del transporte reverso de colesterol específico de macrófagos. / ApoA-I and apoA-II are the most abundant apolipoprotein in HDL. ApoA-I plasma concentration is inversely related to coronary artery disease risk and its role in HDL is well known. ApoA-I has a very important structural role in HDL, it binds to HDL receptors triggering cholesterol efflux from cell membranes and is LCAT cofactor. However, the role of apoA-II in lipoprotein metabolism and atherosclerosis development is less known.The high expressor human apoA-II transgenic mice (line 11.1) challenged with atherogenic diet develops combined hiperlipidemia, HDL deficiency and high atherosclerosis susceptibility. Line 11.1 mice showed a dramatic increase in staining area for oxidation-derived epitopes in aortic lesions, compared to control mice. HDL from 11.1 line presented impaired ability to protect apoB lipoprotein against oxidation when compared to control and 25.3 mouse line (low human apoA-II expressor). HDL from 11.1 mice showed an altered composition with high quantities of human apoA-II, low apoA-I, PON1 and PAF-AH, that likely accounts for the impaired protection against oxidation found in these mice. However, these changes are not due to changes in transcription of apoA-I, PON1, PAF-AH or LCAT genes. On the other hand, human apoA-II is able to displace PON1 from the HDL particle, as shown by in vitro assays. Impairment of antioxidant ability of HDL from 11.1 transgenic mice could explain, at least in part, the enhanced atherosclerosis susceptibility found in these animals in atherogenic diet.In the study of the ability of HDL from 11.1 transgenic mice to carry out reverse cholesterol transport, the results showed that, despite their HDL deficiency, 11.1 transgenic mice did not presented an altered flux in macrophage-specific reverse cholesterol transport. Therefore, the enhanced atherosclerosis susceptibility of 11.1 transgenic mice does not seem attributable to an impaired macrophage-specific reverse cholesterol transport.

Diss. (sammanfattning) Linköping : Univ., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 5 uppsatser.