RESUMO
BACKGROUND AND AIMS: Drug-resistant epilepsy (DRE) is a common and important neurological problem to identify with scope for curative surgical treatment if underlying cause is delineated. There are very few prospective structured studies in our population. This study aimed to look at the neuroimaging profile of DRE presenting in a tertiary care center in South India. MATERIALS AND METHODS: All patients diagnosed clinically as DRE as per International League Against Epilepsy (ILAE) criteria and who underwent magnetic resonance imaging (MRI) over a period of 24 months were included in the study. Their clinical and MRI features were documented and analyzed. RESULTS: A total of 150 patients diagnosed with DRE were included in the study. Clinically, 96 of them presented with generalized tonic-clonic seizures (GTCS), 36 with complex partial seizures (CPS), 14 with simple focal seizures, and two each with atonic seizures and focal seizures with secondary generalization. Magnetic resonance imaging (done in 1.5 T) was normal in 32%. In those with abnormal MRI, mesial temporal sclerosis (MTS) was the commonest pathology seen in 41.3%, followed by cortical malformations (6.7%), tumors (2.6%), vascular malformations (2.7%), and other nonspecific lesions (12%). CONCLUSION: The clinical and neuroimaging profile of DRE showed that DRE is more common in younger age (of less than 30 years); presents mainly with GTCS or CPS; mesial temporal sclerosis is the commonest underlying pathology which was bilateral in 8.6%; temporal lobe lesions predominate (49.3% of all DRE); and cortical malformation, low-grade tumors, and vascular lesions are other important causes.
Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Epilepsia , Adulto , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Eletroencefalografia , Epilepsia/complicações , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/patologia , Epilepsia do Lobo Temporal/cirurgia , Humanos , Imageamento por Ressonância Magnética , Neuroimagem , Estudos Prospectivos , Esclerose , Convulsões/complicações , Centros de Atenção TerciáriaRESUMO
Heme catabolic processes produce the antioxidants biliverdin and bilirubin, as well as the potent prooxidant free iron. Since these products have opposing effects on oxidative stress, it is not clear whether heme catabolism promotes or inhibits inflammatory processes, including atherosclerotic lesion formation. Heme oxygenase (HO) catalyzes the rate-limiting step of heme catabolism. We used cocultures of human aortic endothelial cells and smooth muscle cells to examine the possible role of HO in early atherosclerosis. Heme oxygenase-1 (HO-1), the inducible isoform of HO, was highly induced by mildly oxidized LDL, and augmented induction was observed with hemin pretreatment. This augmented HO-1 induction resulted in the reduction of monocyte chemotaxis in response to LDL oxidation. Conversely, inhibition of HO by a specific inhibitor, Sn-protoporphyrin IX, enhanced chemotaxis. Furthermore, pretreatment with biliverdin or bilirubin, the products of HO, reduced chemotaxis. Oxidized phospholipids in the mildly oxidized LDL appear to be responsible for HO-1 induction, since oxidized but not native arachidonic acid-containing phospholipids also induced HO-1. These results suggest that HO-1 induced by mildly oxidized LDL may protect against the induction of inflammatory responses in artery wall cells through the production of the antioxidants biliverdin and bilirubin.
Assuntos
Heme Oxigenase (Desciclizante)/fisiologia , Lipoproteínas LDL/farmacologia , Monócitos/fisiologia , Bilirrubina/farmacologia , Células Cultivadas , Quimiotaxia de Leucócito/efeitos dos fármacos , Técnicas de Cocultura , Endotélio Vascular/enzimologia , Indução Enzimática , Heme Oxigenase-1 , Hemina/farmacologia , Humanos , Proteínas de Membrana , Músculo Liso Vascular/enzimologia , Fosfolipídeos/farmacologiaRESUMO
Rabbit aortic endothelial cells (RAECs) were grown on micropore filters in a device that allowed in situ determination of transendothelial electrical resistance (TEER). Incubation of confluent RAEC monolayers with 2 ng.ml-1 of bacterial LPS for 3 h did not change the protein content or the number of cells on the filters, but resulted in a marked decline in TEER (from 14.1 +/- 0.9 to 5.1 +/- 0.6 omega.cm2) and a significant increase in LDL transport across the monolayers (from 154 +/- 13 to 456 +/- 41 ng. h-1 per cm2). In contrast, exposure of RAEC monolayers for 3 d to as much as 5 micrograms.ml-1 of LPS complexed to LDL (LPS-LDL) did not alter the TEER or LDL transport. LPS-LDL was transported across the monolayers at the same rate as LDL. While microgram quantities of LPS complexed to LDL did not disrupt the integrity of the endothelial monolayer, incubation of RAECs with transported LPS-LDL at concentrations of 25-100 ng LPS.ml-1 resulted in a two- to ninefold increase in the secretion of monocyte chemotactic activity by these cells. Incubation of rabbit aortic smooth muscle cells with transported LPS-LDL at concentrations of 25-100 ng LPS.ml-1 resulted in a two- to threefold increase in the secretion of monocyte chemotactic activity. We propose that LDL protects endothelial cells from the acute toxicity of LPS but the resulting complexes are transported across the endothelium in a biologically active form that can initiate an inflammatory response.
Assuntos
Endotélio Vascular/metabolismo , Lipopolissacarídeos/metabolismo , Lipoproteínas LDL/metabolismo , Animais , Transporte Biológico , Quimiotaxia de Leucócito , Condutividade Elétrica , Endotoxinas/metabolismo , Técnicas In Vitro , Monócitos/fisiologia , CoelhosRESUMO
Minimally modified low density lipoprotein (MM-LDL), derived by mild iron oxidation or prolonged storage at 4 degrees C, has been shown to induce certain inflammatory responses in vascular cells in tissue culture. These include induction of monocyte (but not neutrophil) adherence to endothelial cells (EC), induction of EC production of colony stimulating factors (CSF), and induction of EC and smooth muscle cell production of monocyte chemotactic protein (MCP-1). To test for biologic activity in vivo, microgram quantities of MM-LDL were injected into mice, sera were assayed for CSF activity, and tissues were subjected to Northern analysis. After injection of MM-LDL, CSF activity increased approximately 7-26-fold but remained near control levels after injection of native LDL. Essentially all of the induced CSF activity was due to macrophage CSF as judged by antibody inhibition. Injection of MM-LDL into a mouse strain (C3H/HeJ) that is resistant to bacterial LPS gave similar results, indicating that the induction of CSF was not due to contaminating LPS and suggesting that there are differences in the pathways by which LPS and MM-LDL trigger cytokine production. In addition, after injection of MM-LDL, mRNA for JE, the mouse homologue of MCP-1, was markedly induced in various tissues, but was not induced after injection of native LDL. We conclude, therefore, that MM-LDL is biologically active in vivo and may contribute to the early stages of atherosclerosis by acting as an inflammatory agent.
Assuntos
Lipoproteínas LDL/química , Animais , Sequência de Bases , Northern Blotting , Quimiocina CCL2 , Fatores Quimiotáticos/genética , Expressão Gênica , Lipoproteínas LDL/metabolismo , Fator Estimulador de Colônias de Macrófagos/sangue , Camundongos , Dados de Sequência Molecular , Oligonucleotídeos/química , Oxirredução , RNA Mensageiro/genética , Relação Estrutura-AtividadeRESUMO
Human aortic endothelial cells (EC) and smooth muscle cells (SMC) were isolated and used to form a multilayer of EC-SMC separated by a layer of collagen. SMC and/or collagen layers exerted minimal effects on Na+ transport but impeded the transport of LDL. The presence of an endothelial monolayer markedly reduced the transport of Na+ and LDL. When monocytes were presented to the complete coculture, in the absence of added chemoattractant, one monocyte entered the subendothelial space for every one to three EC present. In contrast, neither collagen nor SMC plus collagen nor EC plus collagen induced comparable monocyte migration. Despite massive migration of monocytes into the coculture, no significant alteration in Na+ transport was observed. LDL transport into the preparation during massive monocyte migration increased modestly, but this was far less than the amount of LDL transported in the absence of an endothelial monolayer. We conclude that (a) the endothelial monolayer was the principal permeability barrier, (b) a substantial migration of monocytes occurred in the absence of added chemoattractant when both EC and SMC were present in the coculture, (c) endothelial barrier function was largely maintained after monocyte migration; and (d) these experiments indicate the need to study all three cell types (monocytes, EC, and SMC) together to understand the complex interactions that occur between these cells.
Assuntos
Movimento Celular , Endotélio Vascular/citologia , Monócitos/citologia , Músculo Liso Vascular/citologia , Adulto , Aorta , Adesão Celular , Células Cultivadas , Humanos , Lipoproteínas LDL/farmacocinética , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Sódio/farmacocinéticaRESUMO
Iron promotes cellular damage via its capacity to catalyze hydroxyl radical formation and by peroxidation of unsaturated lipids. The major cellular iron storage depot, ferritin, acts as a critical antioxidant defense by sequestering unbound or "free" iron, limiting its participation in damaging oxidative reactions. In this study, we investigated the relationship between LDL modified by artery wall cells and the regulation of intracellular free iron levels in the mouse model and in a human aortic endothelial and smooth muscle cell coculture system. We found in response to an atherogenic diet, fatty streak-resistant C3H/HeJ mice exhibited higher levels of liver apoferritin and lower intracellular concentrations of free iron than did fatty streak-susceptible C57 BL/6J mice. Also, ferritin repressor protein mRNA was not significantly suppressed after 15 wk on the atherogenic diet in female C57BL/6J mice, which exhibit the most extensive fatty streak formation, but was significantly reduced in C3H/HeJ mice. Iron loading of coculture cells resulted in elevations of cellular free iron and enhanced LDL-induced monocyte transmigration. Pretreatment of cells with apoferritin completely abolished iron-induced LDL modification. Addition of LDL to cocultures resulted in elevations in lipid peroxidation products, intracellular free iron, apoferritin mRNA expression, and apoferritin synthesis, suggesting a possible relationship between the oxidative modification of LDL and iron metabolism.
Assuntos
Aorta/metabolismo , Apoferritinas/metabolismo , Arteriosclerose/metabolismo , Endotélio Vascular/fisiologia , Expressão Gênica , Ferro/metabolismo , Peroxidação de Lipídeos , Lipoproteínas LDL/farmacologia , Fígado/metabolismo , Músculo Liso Vascular/metabolismo , Proteínas de Ligação a RNA/biossíntese , Transferrina/metabolismo , Animais , Arteriosclerose/patologia , Sequência de Bases , Northern Blotting , Células Cultivadas , Dieta Aterogênica , Feminino , Homeostase/efeitos dos fármacos , Humanos , Proteína 1 Reguladora do Ferro , Proteínas Reguladoras de Ferro , Lipoproteínas LDL/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Caracteres Sexuais , Especificidade da EspécieRESUMO
In an effort to identify genetic factors contributing to atherogenesis, we have studied inbred strains of mice that are susceptible (C57BL/6J) and resistant (C3H/HeJ) to diet-induced aortic fatty streak lesions. When maintained on a low-fat diet, HDL isolated from both strain C57BL/6J (B6) and C3H/HeJ (C3H) mice protect against LDL oxidation in a coculture model of the artery wall. However, when maintained on an atherogenic diet high in fat and cholesterol, the HDL isolated from B6 mice lose the capacity to protect, whereas HDL from C3H mice protect equally well. Associated with the loss in the ability of HDL to protect is a decrease in the activity of serum paraoxonase, a serum esterase carried on HDL that has previously been shown to protect against LDL oxidation in vitro. The levels of paraoxonase mRNA decreased in B6 mice upon challenge with the atherogenic diet but increased in C3H, indicating that paraoxonase production is under genetic control. In a set of recombinant inbred strains derived from the B6 and C3H parental strains, low paraoxonase mRNA levels segregated with aortic lesion development, supporting a role for paraoxonase in atherogenesis.
Assuntos
Arteriosclerose/etiologia , Dieta , Esterases/sangue , Sequência de Aminoácidos , Animais , Arteriosclerose/enzimologia , Arteriosclerose/genética , Arildialquilfosfatase , Sequência de Bases , Clonagem Molecular , Cruzamentos Genéticos , DNA Complementar/genética , Dieta Aterogênica , Dieta com Restrição de Gorduras , Modelos Animais de Doenças , Esterases/genética , Feminino , Expressão Gênica , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas HDL/farmacologia , Lipoproteínas LDL/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Oxirredução , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos , Especificidade da EspécieRESUMO
Addition of leumedin, N-[9H-(2,7-dimethylfluorenyl-9-methoxy) carbon]-L-leucine at 30-60 microM together with LDL almost completely prevented the induction of monocyte chemotactic protein mRNA, reduced monocyte chemotactic protein 1 levels by 84%, and inhibited monocyte migration into the subendothelial space of cocultures of human aortic wall cells by < or = 98%. LDL incubated with leumedin formed a stable complex that remained intact even after refloating in an ultracentrifuge. Leumedin at 50 microM did not change conjugated diene formation during coculture modification of LDL or Cu++ catalyzed oxidation of LDL. Unlike LDL from control rabbits, LDL isolated from rabbits that were injected with 20 mg/kg leumedin was remarkably resistant to modification by the coculture and did not induce monocyte migration to a significant degree. Moreover, HDL isolated from rabbits injected with leumedin was far more effective in protecting against LDL modification by the artery wall cocultures than HDL from control rabbits. We conclude that leumedins can associate with lipoproteins in vivo, rendering LDL resistant to biological modification and markedly amplifying the protective capacity of HDL against in vitro LDL oxidation by artery wall cells.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aorta/fisiologia , Endotélio Vascular/fisiologia , Leucina/análogos & derivados , Lipoproteínas LDL/metabolismo , Monócitos/fisiologia , Músculo Liso Vascular/fisiologia , Animais , Anti-Inflamatórios não Esteroides/metabolismo , Aorta/efeitos dos fármacos , Comunicação Celular , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Cobre/farmacologia , Humanos , Leucina/metabolismo , Leucina/farmacologia , Lipoproteínas HDL/metabolismo , Lipoproteínas VLDL/metabolismo , Monócitos/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , CoelhosRESUMO
Incubation of cocultures of human aortic endothelial (HAEC) and smooth muscle cells (HASMC) with LDL in the presence of 5-10% human serum resulted in a 7.2-fold induction of mRNA for monocyte chemotactic protein 1 (MCP-1), a 2.5-fold increase in the levels of MCP-1 protein in the coculture supernatants, and a 7.1-fold increase in the transmigration of monocytes into the subendothelial space of the cocultures. Monocyte migration was inhibited by 91% by antibody to MCP-1. Media collected from the cocultures that had been incubated with LDL induced target endothelial cells (EC) to bind monocyte but not neutrophil-like cells. Media collected from cocultures that had been incubated with LDL-induced monocyte migration into the subendothelial space of other cocultures that had not been exposed to LDL. In contrast, media from separate cultures of EC or smooth muscle cells (SMC) containing equal number of EC or SMC compared to coculture and incubated with the same LDL did not induce monocyte migration when incubated with the target cocultures. High density lipoprotein HDL, when presented to cocultures together with LDL, reduced the increased monocyte transmigration by 91%. Virtually all of the HDL-mediated inhibition was accounted for by the HDL2 subfraction. HDL3 was essentially without effect. Apolipoprotein AI was also ineffective in preventing monocyte transmigration while phosphatidylcholine liposomes were as effective as HDL2 suggesting that lipid components of HDL2 may have been responsible for its action. Preincubating LDL with beta-carotene or with alpha-tocopherol did not reduce monocyte migration. However, pretreatment of LDL with probucol or pretreatment of the cocultures with probucol, beta-carotene, or alpha-tocopherol before the addition of LDL prevented the LDL-induced monocyte transmigration. Addition of HDL or probucol to LDL after the exposure to cocultures did not prevent the modified LDL from inducing monocyte transmigration in fresh cocultures. We conclude that cocultures of human aortic cells can modify LDL even in the presence of serum, resulting in the induction of MCP-1, and that HDL and antioxidants prevent the LDL induced monocyte transmigration.
Assuntos
Fatores Quimiotáticos/biossíntese , Lipoproteínas HDL/farmacologia , Lipoproteínas LDL/farmacologia , Monócitos/fisiologia , Antioxidantes/farmacologia , Aorta/metabolismo , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Quimiocina CCL2 , Humanos , Oxigênio/metabolismoRESUMO
Medium from cocultures of human aortic endothelial cells (HAEC) and smooth muscle cells (HASMC) taken from the same donor contained approximately two- to fourfold more macrophage colony-stimulating factor, granulocyte/macrophage colony-stimulating factor, and up to 5.1-fold more transforming growth factor beta than could be accounted for by the sum of the activities of media from equivalent numbers of HAEC and HASMC cultured separately. After pulse labeling, immunoprecipitated [35S]fibronectin and [14C]collagen were also found to be substantially increased in the coculture compared to the sum of HAEC and HASMC cultured separately. The cocultivation of HAEC and HASMC resulted in a 2.7-fold increase in connexin43 messenger RNA. When direct physical contact between HAEC and HASMC was prevented by a membrane that was permeable to medium, the levels of [35S]fibronectin and [14C]collagen in the coculture were significantly reduced. Monocytes cultured alone contained low levels of [35S]fibronectin and [14C]collagen but when added to the coculture there was up to a 22-fold increase in [35S]fibronectin and a 1.9-fold increase in [14C]collagen compared to the coculture alone. The increase in fibronectin was prevented in the presence of neutralizing antibody to interleukin 1 and antibody to interleukin 6 by 45% and 67%, respectively. Addition of monocytes to cocultures also induced the levels of mRNA for connexin43 by 2.8-fold. We conclude that the interaction of HAEC, HASMC, and monocytes in coculture can result in marked increases in the levels of several biologically important molecules and that increased gap junction formation between the cells and interleukins 1 and 6 may be partially responsible for these changes.
Assuntos
Comunicação Celular , Endotélio Vascular/fisiologia , Interleucina-1/fisiologia , Interleucina-6/fisiologia , Proteínas de Membrana/genética , Monócitos/fisiologia , RNA Mensageiro/análise , Aorta/fisiologia , Células Cultivadas , Colágeno/análise , Conexinas , Fibronectinas/análise , Humanos , Fator de Crescimento Transformador beta/análiseRESUMO
Mildly oxidized low density lipoprotein (MM-LDL) produced by oxidative enzymes or cocultures of human artery wall cells induces endothelial cells to produce monocyte chemotactic protein-1 and to bind monocytes. HDL prevents the formation of MM-LDL by cocultures of artery wall cells. Using albumin treatment and HPLC we have isolated and partially characterized bioactive oxidized phospholipids in MM-LDL. Platelet activating factor-acetylhydrolase (PAF-AH), a serine esterase, hydrolyzes short chain acyl groups esterified to the sn-2 position of phospholipids such as PAF and particular oxidatively fragmented phospholipids. Treatment of MM-LDL with PAF-AH (2-4 x 10(-2) U/ml) eliminated the ability of MM-LDL to induce endothelial cells to bind monocytes. When HDL protected against the formation of MM-LDL by cocultures, lysophosphatidylcholine was detected in HDL; whereas when HDL was pretreated with diisopropyl fluorophosphate, HDL was no longer protective and lysophosphatidylcholine was undetectable. HPLC analysis also revealed that the active oxidized phospholipid species in MM-LDL had been destroyed after PAF-AH treatment. In addition, treatment of MM-LDL with albumin removed polar phospholipids that, when reisolated, induced monocyte binding to endothelial cells. These polar phospholipids, when treated with PAF-AH, lost biological activity and were no longer detected by HPLC. These results suggest that PAF-AH in HDL protects against the production and activity of MM-LDL by facilitating hydrolysis of active oxidized phospholipids to lysolipids, thereby destroying the biologically active lipids in MM-LDL.
Assuntos
Endotélio Vascular/fisiologia , Lipoproteínas LDL/metabolismo , Músculo Liso Vascular/fisiologia , Fosfolipases A/metabolismo , 1-Alquil-2-acetilglicerofosfocolina Esterase , Animais , Aorta/fisiologia , Adesão Celular , Comunicação Celular , Movimento Celular , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Humanos , Lipoproteínas HDL/sangue , Lipoproteínas HDL/isolamento & purificação , Lipoproteínas LDL/sangue , Lipoproteínas LDL/isolamento & purificação , Monócitos/fisiologia , Fosfolipídeos/análise , Fosfolipídeos/isolamento & purificação , Coelhos , Albumina Sérica/farmacologiaRESUMO
Previous studies showed that transgenic mice overexpressing either apolipoprotein AI (apoAI) or apolipoprotein AII (apoAII), the major proteins of HDL, exhibited elevated levels of HDL cholesterol, but, whereas the apoAI-transgenic mice were protected against atherosclerosis, the apoAII-transgenic mice had increased lesion development. We now examine the basis for this striking functional heterogeneity. HDL from apoAI transgenics exhibited an enhanced ability to promote cholesterol efflux from macrophages, but HDL from apoAII transgenics and nontransgenics were not discernibly different in efflux studies. In contrast with HDL from nontransgenics and apoAI transgenics, HDL from the apoAII transgenics were unable to protect against LDL oxidation in a coculture model of the artery wall. Furthermore, HDL taken from apoAII-transgenic mice, but not HDL taken from either the apoAI transgenics or nontransgenic littermate controls, by itself stimulated lipid hydroperoxide formation in artery wall cells and induced monocyte transmigration, indicating that the apoAII-transgenic HDL were in fact proinflammatory. This loss in the ability of the apoAII-transgenic HDL to function as an antioxidant/antiinflammatory agent was associated with a decreased content of paraoxonase, an enzyme that protects against LDL oxidation. Reconstitution of the apoAII transgenic HDL with purified paraoxonase restored both paraoxonase activity and the ability to protect against LDL oxidation. We conclude that overexpression of apoAII converts HDL from an anti- to a proinflammatory particle and that paraoxonase plays a role in this transformation.
Assuntos
Apolipoproteína A-II/metabolismo , Colesterol/metabolismo , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , 1-Alquil-2-acetilglicerofosfocolina Esterase , Animais , Aorta/metabolismo , Aorta/patologia , Apolipoproteína A-I/metabolismo , Apolipoproteína A-II/genética , Arteriosclerose/etiologia , Arildialquilfosfatase , Técnicas de Cocultura , Esterases/metabolismo , Regulação da Expressão Gênica , Peróxidos Lipídicos/metabolismo , Lipoproteínas HDL/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oxirredução , Fosfolipases A/metabolismoRESUMO
We previously reported that high density lipoprotein (HDL) protects against the oxidative modification of low density lipoprotein (LDL) induced by artery wall cells causing these cells to produce pro-inflammatory molecules. We also reported that enzyme systems associated with HDL were responsible for this anti-inflammatory property of HDL. We now report studies comparing HDL before and during an acute phase response (APR) in both humans and a croton oil rabbit model. In rabbits, from the onset of APR the protective effect of HDL progressively decreased and was completely lost by day three. As serum amyloid A (SAA) levels in acute phase HDL (AP-HDL) increased, apo A-I levels decreased 73%. Concomitantly, paraoxonase (PON) and platelet activating factor acetylhydrolase (PAF-AH) levels in HDL declined 71 and 90%, respectively, from days one to three. After day three, there was some recovery of the protective effect of HDL. AP-HDL from human patients and rabbits but not normal or control HDL (C-HDL) exhibited increases in ceruloplasmin (CP). This increase in CP was not seen in acute phase VLDL or LDL. C-HDL incubated with purified CP and re-isolated (CP-HDL), lost its ability to inhibit LDL oxidation. Northern blot analyses demonstrated enhanced expression of MCP-1 in coculture cells treated with AP-HDL and CP-HDL compared to C-HDL. Enrichment of human AP-HDL with purified PON or PAF-AH rendered AP-HDL protective against LDL modification. We conclude that under basal conditions HDL serves an anti-inflammatory role but during APR displacement and/or exchange of proteins associated with HDL results in a pro-inflammatory molecule.
Assuntos
Endotélio Vascular/fisiologia , Inflamação/fisiopatologia , Lipoproteínas HDL/metabolismo , Lipoproteínas HDL/farmacologia , Músculo Liso Vascular/fisiologia , 1-Alquil-2-acetilglicerofosfocolina Esterase , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Aorta/citologia , Aorta/fisiologia , Arildialquilfosfatase , Sequência de Bases , Adesão Celular , Células Cultivadas , Ceruloplasmina/biossíntese , Quimiocina CCL2/biossíntese , Técnicas de Cocultura , Óleo de Cróton , Primers do DNA , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Esterases/metabolismo , Expressão Gênica , Humanos , Lipoproteínas HDL/isolamento & purificação , Masculino , Dados de Sequência Molecular , Monócitos/citologia , Monócitos/fisiologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Oxirredução , Fosfolipases A/metabolismo , CoelhosRESUMO
Our group has previously demonstrated that oxidized phospholipids in mildly oxidized LDL (MM-LDL) produced by oxidation with lipoxygenase, iron, or cocultures of artery wall cells increase monocyte-endothelial interactions and this sequence of events is blocked by HDL. To obtain further insight into the mechanism by which HDL abolishes the activity of MM-LDL we investigated the effect of the HDL-associated ester hydrolase paraoxonase (PON). Treatment of MM-LDL with purified PON significantly reduced the ability of MM-LDL to induce monocyte-endothelial interactions. Inactivation of PON by pretreating HDL with heat or EDTA reduced the ability of HDL to inhibit LDL modification. HPLC analysis of phospholipids isolated from MM-LDL before and after treatment with purified PON showed that the 270 nm absorbance of phospholipids was decreased, while no effect was observed on 235 nm absorbance. Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (Ox-PAPC) and specific fractions of Ox-PAPC isolated by HPLC induced the same monocyte-endothelial interactions as did MM-LDL. Biologically active and inactive HPLC fractions of Ox-PAPC were compared by fast atom bombardment-mass spectrometry which revealed that active fractions possessed ions with a mass to charge [correction of change] ratio greater than native PAPC by multiples of 16 D suggesting the addition of 3 and 4 oxygen atoms to PAPC. Comparison of Ox-PAPC by fast atom bombardment-mass spectrometry before and after PON treatment showed that PON destroyed these multi-oxygenated molecules found in biologically active fractions of Ox-PAPC. These results suggest that PON in HDL may protect against the induction of inflammatory responses in artery wall cells by destroying biologically active lipids in mildly oxidized LDL.
Assuntos
Endotélio Vascular/fisiologia , Esterases/sangue , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Lipoproteínas LDL/farmacologia , Monócitos/fisiologia , 1-Alquil-2-acetilglicerofosfocolina Esterase , Animais , Aorta , Arildialquilfosfatase , Células Cultivadas , Técnicas de Cocultura , Ácido Edético/farmacologia , Endotélio Vascular/citologia , Esterases/isolamento & purificação , Humanos , Inflamação , Cinética , Lipoproteínas HDL/isolamento & purificação , Lipoproteínas LDL/isolamento & purificação , Modelos Biológicos , Monócitos/citologia , Oxirredução , Fosfolipases A/metabolismo , Fosfolipídeos/isolamento & purificação , Fosfolipídeos/metabolismo , Coelhos , Espectrometria de Massas de Bombardeamento Rápido de ÁtomosRESUMO
Rabbit aortic endothelial cells (RAEC) were grown on micropore filters in a new device. This system allowed in situ measurement of transendothelial electrical resistance (TEER). The monolayers demonstrated a TEER of 14 +/- 1 omega X cm2 at confluence. No difference was seen in the transport of low density lipoproteins (LDL) across endothelial cell monolayers obtained from normal or Watanabe heritable hyperlipidemic rabbits, indicating that the LDL receptor was not involved in the LDL transport. TEER was inversely correlated with 22Na transport (r2 = 0.93, P = less than 0.001) but not with 125I-LDL transport. The amount of LDL transported at 15 degrees C or across glutaraldehyde-fixed monolayers was half that of the controls at 37 degrees C. Preincubation of the monolayers with rabbit beta-migrating very low density lipoproteins (beta-VLDL) increased cholesterol content by 65%, and the transport of albumin and LDL doubled without a change in TEER. Removal of beta-VLDL from the culture medium resulted in the return of cellular cholesterol content and LDL transport to control values. We conclude that preincubation of RAEC with beta-VLDL resulted in an increased permeability to LDL and albumin, and that beta-VLDL may promote increased transendothelial transport of macromolecules in cholesterol-fed rabbits.
Assuntos
Condutividade Elétrica , Endotélio/efeitos dos fármacos , Lipoproteínas VLDL/farmacologia , Albuminas/metabolismo , Animais , Aorta , Transporte Biológico/efeitos dos fármacos , Células Cultivadas , Endotélio/metabolismo , Endotélio/ultraestrutura , Humanos , Lipoproteínas LDL/metabolismo , Substâncias Macromoleculares , Microscopia Eletrônica , Coelhos , Sódio/metabolismoRESUMO
We have examined the effects of mildly oxidized LDL and atherosclerosis on the levels of two proteins associated with HDL; apolipoprotein J (apoJ), and paraoxonase (PON). On an atherogenic diet, PON activity decreased by 52%, and apoJ levels increased 2.8-fold in fatty streak susceptible mice, C57BL/6J (BL/6), but not in fatty streak resistant mice, C3H/HeJ (C3H). Plasma PON activity was also significantly decreased, and apoJ levels were markedly increased in apolipoprotein E knockout mice on the chow diet, resulting in a 9.2-fold increase in the apoJ/PON ratio as compared to controls. Furthermore, a dramatic increase in the apoJ/PON ratio (over 100-fold) was observed in LDL receptor knockout mice when they were fed a 0.15%-cholesterol-enriched diet. Injection of mildly oxidized LDL (but not native LDL) into BL/6 mice (but not in C3H mice) on a chow diet resulted in a 59% decrease in PON activity (P < 0.01) and a 3.6-fold increase in apoJ levels (P < 0.01). When an acute phase reaction was induced in rabbits, or the rabbits were placed on an atherogenic diet, hepatic mRNA for apoJ was increased by 2.7-fold and 2.8-fold, respectively. Treatment of HepG2 cells in culture with mildly oxidized LDL (but not native LDL) resulted in reduced mRNA levels for PON (3.0-fold decrease) and increased mRNA levels for apoJ (2.0-fold increase). In normolipidemic patients with angiographically documented coronary artery disease who did not have diabetes and were not on lipid-lowering medication (n = 14), the total cholesterol/HDL cholesterol ratio was 3.1+/-0.9 as compared to 2.9+/-0.4 in the controls (n = 19). This difference was not statistically significant. In contrast, the apoJ/PON ratio was 3.0+/-0.4 in the patients compared to 0.72+/-0.2 in the controls (P < 0.009). In a subset of these normolipidemic patients (n = 5), the PON activity was low (48+/-6.6 versus 98+/-17 U/ml for controls; P < 0.009), despite similar normal HDL levels, and the HDL from these patients failed to protect against LDL oxidation in co-cultures of human artery wall cells. We conclude that: (a) mildly oxidized LDL can induce an increased apoJ/PON ratio, and (b) the apoJ/PON ratio may prove to be a better predictor of atherosclerosis than the total cholesterol/HDL cholesterol ratio.
Assuntos
Esterases/metabolismo , Glicoproteínas/metabolismo , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Chaperonas Moleculares , Animais , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Artérias/efeitos dos fármacos , Artérias/metabolismo , Arteriosclerose/etiologia , Arteriosclerose/metabolismo , Arildialquilfosfatase , Sequência de Bases , Células Cultivadas , Colesterol/metabolismo , Clusterina , Dieta Aterogênica , Esterases/genética , Glicoproteínas/genética , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/química , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sondas de Oligonucleotídeos/genética , Oxirredução , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos , Receptores de LDL/genética , Receptores de LDL/metabolismoRESUMO
Objectives: This study evaluated the perception and practices of health care providers (physicians, diabetologists, and endocrinologists) regarding the treatment of hypertension in patients with diabetes in India. Methods: Health care providers throughout India who treated patients with diabetes and hypertension were invited to participate in an online survey and periodic 21 virtual meetings. They were questioned about their perception and practices in managing these patients, and strategies to improve blood pressure (BP). Results: The online survey was completed by 2,513 health care providers, and 344 participated in virtual meetings. More than 50% reported that 31–50% of their patients with diabetes also had hypertension. Home BP monitoring was recommended by 88%, and lifestyle modifications were consistently recommended. Choice of antihypertensive treatment varied based on comorbidities, and a renin–angiotensin system blocker plus a calcium channel blocker (CCB) was the most common combination for dual antihypertensive therapy. Suggested strategies to improve BP control included patient awareness/education, lifestyle modifications, better follow-up/monitoring, and optimization of therapy. Conclusion: Indian health care providers were aware of clinical recommendations and practices regarding treatment of patients with diabetes and hypertension, and generally make clinical decisions consistent with current guidelines. Optimization of care for these patients is essential to reduce cardiovascular disease risk and improve patient outcomes.
RESUMO
BACKGROUND: Viruses have been identified as one of a variety of potential agents that are implicated in atherogenesis. METHODS AND RESULTS: C57BL/6J mice were killed before or 2, 3, 5, 7, or 9 days after intranasal infection with 10(5) plaque-forming units (pfu) of Influenza A strain WSN/33. Peak infectivity in lungs was reached by 72 hours, and it returned to baseline by 9 days. No viremia was observed at any time. The activities of paraoxonase and platelet-activating factor acetylhydrolase in HDL decreased after infection and reached their lowest levels 7 days after inoculation. The ability of HDL from infected mice to inhibit LDL oxidation and LDL-induced monocyte chemotactic activity in human artery wall cell cocultures decreased with time after inoculation. Moreover, as the infection progressed, LDL more readily induced monocyte chemotaxis. Peak interleukin-6 and serum amyloid A plasma levels were observed at 2 and 7 days after inoculation. HDL apoA-I levels did not change. ApoJ and ceruloplasmin levels in HDL peaked 3 days after infection. Ceruloplasmin remained elevated throughout the time course, whereas apoJ levels decreased toward baseline after the third day. CONCLUSIONS: We conclude that alterations in the relative levels of paraoxonase, platelet-activating factor acetylhydrolase, ceruloplasmin, and apoJ in HDL occur during acute influenza infection, causing HDL to lose its anti-inflammatory properties.
Assuntos
Inflamação/sangue , Inflamação/virologia , Influenza Humana/sangue , Lipoproteínas HDL/metabolismo , 1-Alquil-2-acetilglicerofosfocolina Esterase , Doença Aguda , Reação de Fase Aguda/metabolismo , Reação de Fase Aguda/virologia , Animais , Apolipoproteínas/sangue , Artérias/citologia , Artérias/efeitos dos fármacos , Artérias/metabolismo , Arildialquilfosfatase , Células Cultivadas , Ceruloplasmina/análise , Ceruloplasmina/metabolismo , Quimiotaxia/efeitos dos fármacos , Clusterina , Modelos Animais de Doenças , Esterases/análise , Esterases/metabolismo , Feminino , Glicoproteínas/análise , Glicoproteínas/metabolismo , Humanos , Vírus da Influenza A/crescimento & desenvolvimento , Vírus da Influenza A/isolamento & purificação , Influenza Humana/virologia , Interleucina-6/sangue , Lipoproteínas HDL/química , Lipoproteínas HDL/farmacologia , Lipoproteínas LDL/sangue , Lipoproteínas LDL/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Chaperonas Moleculares/análise , Chaperonas Moleculares/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fosfolipases A/análise , Fosfolipases A/metabolismo , Proteína Amiloide A SéricaRESUMO
BACKGROUND: Carotenoids are hypothesized to explain some of the protective effects of fruit and vegetable intake on risk of cardiovascular disease. The present study assessed the protective effects of the oxygenated carotenoid lutein against early atherosclerosis. EPIDEMIOLOGY: Progression of intima-media thickness (IMT) of the common carotid arteries over 18 months was determined ultrasonographically and was related to plasma lutein among a randomly sampled cohort of utility employees age 40 to 60 years (n=480). Coculture: The impact of lutein on monocyte response to artery wall cell modification of LDL was assessed in vitro by quantification of monocyte migration in a coculture model of human intima. Mouse models: The impact of lutein supplementation on atherosclerotic lesion formation was assessed in vivo by assigning apoE-null mice to chow or chow plus lutein (0.2% by weight) and LDL receptor-null mice to Western diet or Western diet plus lutein. IMT progression declined with increasing quintile of plasma lutein (P for trend=0.007, age-adjusted; P=0.0007, multivariate). Covariate-adjusted IMT progression (mean+/-SEM) was 0.021+/-0.005 mm in the lowest quintile of plasma lutein, whereas progression was blocked in the highest quintile (0.004+/-0.005 mm; P=0.01). In the coculture, pretreatment of cells with lutein inhibited LDL-induced migration in a dose-dependent manner (P<0.05). Finally, in the mouse models, lutein supplementation reduced lesion size 44% in apoE-null mice (P=0.009) and 43% in LDL receptor-null mice (P=0.02). CONCLUSIONS: These epidemiological, in vitro, and mouse model findings support the hypothesis that increased dietary intake of lutein is protective against the development of early atherosclerosis.
Assuntos
Arteriosclerose/prevenção & controle , Luteína/administração & dosagem , Adulto , Animais , Apolipoproteínas E/deficiência , Arteriosclerose/sangue , Arteriosclerose/diagnóstico , Arteriosclerose/epidemiologia , Arteriosclerose/patologia , Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/patologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Estudos de Coortes , Meios de Cultivo Condicionados/farmacologia , Modelos Animais de Doenças , Progressão da Doença , Relação Dose-Resposta a Droga , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Feminino , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas HDL/farmacologia , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Los Angeles/epidemiologia , Luteína/sangue , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Monócitos/citologia , Monócitos/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Oxirredução/efeitos dos fármacos , Fatores de Risco , Ultrassonografia , beta Caroteno/sangueRESUMO
Studies from several laboratories suggest that oxidized LDL may play an important role in atherogenesis. Our group previously showed that treatment of aortic endothelial cells with low levels of MM-LDL caused increased expression of MCP-1, M-CSF, tissue factor, and a monocyte-binding protein. In these studies MM-LDL was produced by storage of native LDL. We now show that cocultures of endothelial and smooth muscle cells can also produce MM-LDL from native LDL. This production of MM-LDL by cells is prevented by preincubating the LDL with probucol or vitamin E. However, addition of antioxidants to MM-LDL did not block its action. In past studies we also showed that endothelial cells exhibit differential sensitivity to the effects of MM-LDL. We report herein that in resistant cells there is no elevation of catalase, glutathione peroxidase, or copper-zinc-dependent SOD. However, manganese-dependent SOD is elevated in resistant cells. Ways in which MM-LDL production may be elevated in poorly controlled diabetics subjects are discussed.