RESUMO

The accumulation of oxidized low-density lipoprotein (oxLDL) and its toxicity in the arterial wall have been implicated in atherosclerosis. This study aimed to investigate the mechanisms underlying the atheroprotective effect of bixin, a carotenoid obtained from the seeds of the tropical plant Bixa orellana, on Cu2+-induced LDL oxidation and oxLDL-mediated effects in J774A.1 macrophage cells. Bixin's effects were compared to those of lycopene, a carotenoid widely studied for its cardiovascular protective effects. LDL was isolated from human plasma, incubated with bixin or lycopene (positive control), and subjected to oxidation with CuSO4. Afterward, bixin or lycopene was incubated with J774A.1 macrophage cells and exposed to oxLDL. The levels of ROS, RNS, GSH, nitrite, mitochondrial function, and foam cell formation, as well as the expression of proteins related to the antioxidant and inflammatory status, were evaluated. The effect of bixin in inhibiting in vitro human-isolated LDL oxidation was more potent (5-6-fold) than that of lycopene. Bixin pretreatment reduced the atherogenic signaling triggered by oxLDL in the macrophages, namely the generation of reactive species, disturbance of nitric oxide homeostasis, mitochondrial dysfunction, and foam cell formation. The cytoprotective effects of bixin were accompanied by the upregulation of Nrf2 and the downregulation of the NF-kB pathways. Lycopene showed the same protective effect as bixin, except that it did not prevent mitochondrial dysfunction. The efficient performance of bixin makes it an ideal candidate for further trials as a new nutraceutical compound for the prevention of atherosclerosis.

RESUMO

Resumo Fundamento A formação de células espumosas ocorre devido ao aumento em lipoproteína plasmática de baixa densidade (LDL) e desregulação da inflamação, sendo importante para o desenvolvimento da aterosclerose. Objetivo Avaliar o perfil do fator de necrose tumoral alfa (TNF-α) e da interleucina-6 (IL-6) no método de formação da célula espumosa existente, otimizando esse protocolo. Métodos A LDL foi isolada, oxidada e marcada com sonda de isotiocianato de fluoresceína (FITC). As células espumosas foram geradas de célula derivada de monócitos humanos THP-1 e incubadas na ausência (controle) ou presença de FITC-ox-LDL (10, 50, 100, 150 ou 200 μg/mL), por 12, 24, 48 ou 72 horas. A FITC-ox-LDL na célula foi quantificada por microscopia. O ensaio de imunoabsorção enzimática foi avaliado para quantificar a IL-6 e o TNF-α, com um p <0,05 considerado significativo. Resultados Todas as concentrações de FITC-ox-LDL testadas apresentaram fluorescência mais alta em comparação com o controle, demonstrando maior acúmulo de lipoproteínas nas células. Quanto mais alta a concentração de FITC-ox-LDL, maior a produção de TNF-α e IL-6. A produção de IL-6 pelas células espumosas foi detectada até o valor de 150 µg/mL da LDL máxima de estímulo. Concentrações acima de 50 μg/mL de LDL estimularam maior liberação de TNF-α comparado ao controle. Conclusões Nosso modelo contribui para o entendimento da liberação de IL-6 e TNF-α em resposta a várias concentrações de ox-LDL usando o método otimizado para a formação de células espumosas.

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Abstract Background The formation of foam cells occurs due to the increase in low-density plasma lipoprotein (LDL) and dysregulation of inflammation, which is important for the development of atherosclerosis. Objective To evaluate the profile of tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6) in the existing foam cell formation method, optimizing this protocol. Methods The LDL was isolated, oxidized, and labeled with a Fluorescein isothiocyanate (FITC) probe. Foam cells were generated from THP-1 human monocyte-derived cells and incubated in the absence (control) or presence of FITC-ox-LDL (10, 50, 100, 150, or 200 μg/mL), for 12, 24, 48, or 72 hours. The accumulated FITC-ox-LDL in the cell was quantified by microscopy. The enzyme-linked immunosorbent assay was evaluated to quantify the IL-6 and TNF-α, with p < 0.05 considered significant. Results All the FITC-ox-LDL concentrations tested showed a higher fluorescence when compared to the control, showing a greater accumulation of lipoprotein in cells. The higher the concentration of FITC-ox-LDL, the greater the production of TNF-α and IL-6. The production of IL-6 by foam cells was detected up to the value of 150 µg/mL of the maximum stimulus for LDL. Concentrations above 50 μg/mL LDL stimulated greater release of TNF-α compared to control. Conclusions Our model contributes to the understanding of the release of IL-6 and TNF-α in response to different concentrations of ox-LDL, using an optimized method for the formation of foam cells.

RESUMO

Abstract Introduction: Drug-eluting stents (DES) coated with rapamycin or paclitaxel as antiproliferative substances significantly reduced the incidence of clinical restenosis and had fewer side effects after percutaneous coronary intervention. However, DES coated with rapamycin or paclitaxel still cause restenosis due to abnormal tissue growth which remained a therapeutic problem, particularly in certain subgroups, possibly due to drug concentrations. This study examined the impact of different concentrations of rapamycin and paclitaxel on cytokine, cell viability and proliferation in human aortic smooth muscle cells (HASMC)-derived foam cells. Methods: The foam cell model was established in vitro by incubating HASMC with 20 µg/mL oxidized low-density lipoprotein (ox-LDL) for 48 hours. Subsequently, foam cells were treated with different concentrations (0.01 µg/mL, 0.1 µg/mL, 0.5 µg/mL, 1 µg/mL, 5 µg/mL and 10 µg/mL) of rapamycin or paclitaxel for 48 hours, to measure cytokine, cell viability and proliferation by ELISA and MTT, respectively. Finally, viability and proliferation were measured by MTT after the foam cells were treated with 1 µg/mL rapamycin or paclitaxel combined with cytokine antibody for 48 hours. Results: After incubation of HASMC with ox-LDL, the ratios of cholesterol ester and total cholesterol increased significantly (55.29%) (P<0.01). Lipid staining with Oil Red O showed many lipid vacuoles and red dye particles in the cells. Meanwhile, cell viability and proliferation significantly increased compared with the control. This indicated that HASMC had been transformed into foam cells (P<0.01) while rapamycin or paclitaxel concentrations ≥0.1 µg/mL can significantly decrease the foam cell proliferation (P<0.05 or P<0.01), and 1 µg/mL of rapamycin or paclitaxel appeared the most effective concentration. As for cytokines, rapamycin or paclitaxel concentrations ≥1 ug/mL could significantly increase the level of inflammatory cytokines IL-6 (P<0.05 or P<0.01), which was enhanced with the increase of drug concentration. However, rapamycin or paclitaxel concentrations ≥1 µg/mL could significantly reduce the levels of anti-inflammatory cytokines IL-35 and transforming growth factor beta (TGF-β) (P<0.05 or P<0.01), which decreased with the increase of drug concentration. In addition, rapamycin or paclitaxel combined with anti-IL-1β, anti-IL-6, anti- TNF-α or anti-IL-35 had no significant effect on foam cell proliferation compared to the drug alone. However, rapamycin or paclitaxel combined with anti-IL-10 or anti-TGF-β can significantly enhance foam cell proliferation (P<0.01). In addition, there was no difference in the effects of the same concentrations of rapamycin and paclitaxel on foam cells. Conclusion: Although rapamycin or paclitaxel can reduce foam cell proliferation, too high or too low concentrations could decrease effectiveness. In particular, a high dose can induce foam cells to increase inflammatory cytokines secretion, reduce anti-inflammatory cytokines secretion, and thus affect the inhibiting proliferation. For rapamycin- and paclitaxel-eluting stents, this conclusion may explain the clinical observation of in-stent restenosis after percutaneous coronary intervention. DES coated with an appropriate concentration of rapamycin or paclitaxel may, at least to some extent, contribute significantly to reducing incidence of late in-stent restenosis.

RESUMO

Verruciform xanthoma (VX) is a rare benign lesion of unknown etiology, with a rough or papillary aspect, painless, sessile, well-defined, most lesions do not exceed 2 cm in their largest diameter, the degree of keratinization of the surface influences color, varying white to red, affecting mainly the gingiva and alveolar mucosa, and can also be seen in skin and genital. Herein, we present a report a clinical case of oral verruciform xanthoma in the buccal mucosa associated with the lichen planus lesion, as well as the morphological and immunohistochemical characteristics of the lesion. The clinical diagnostic hypothesis of oral lichen planus of the white reticular lesions on the buccal mucosa and on the tongue was confirmed by histopathology before a subepithelial connective tissue exhibiting intense inflammatory infiltrate in a predominantly lymphocytic band. In contrast, the hypothesis of the verrucous lesion in the left buccal mucosa was leukoplakia, with histopathological evidence showing exophytic and digitiform proliferations with parakeratin plugs between the papillary projections. Subepithelial connective tissue was characterized by macrophages with foamy cytoplasm (xanthoma cells). An immunohistochemical examination was performed, showing positivity for CD68, a macrophage marker, in addition to testing by Schiff's periodic acid (PAS) with diastasis, which was detected the presence of lipids inside these macrophages. The patient is free of recurrences of verruciform xanthoma and is being monitored due to the presence of lesions of oral lichen planus.

RESUMO

INTRODUCTION: Drug-eluting stents (DES) coated with rapamycin or paclitaxel as antiproliferative substances significantly reduced the incidence of clinical restenosis and had fewer side effects after percutaneous coronary intervention. However, DES coated with rapamycin or paclitaxel still cause restenosis due to abnormal tissue growth which remained a therapeutic problem, particularly in certain subgroups, possibly due to drug concentrations. This study examined the impact of different concentrations of rapamycin and paclitaxel on cytokine, cell viability and proliferation in human aortic smooth muscle cells (HASMC)-derived foam cells. METHODS: The foam cell model was established in vitro by incubating HASMC with 20 µg/mL oxidized low-density lipoprotein (ox-LDL) for 48 hours. Subsequently, foam cells were treated with different concentrations (0.01 µg/mL, 0.1 µg/mL, 0.5 µg/mL, 1 µg/mL, 5 µg/mL and 10 µg/mL) of rapamycin or paclitaxel for 48 hours, to measure cytokine, cell viability and proliferation by ELISA and MTT, respectively. Finally, viability and proliferation were measured by MTT after the foam cells were treated with 1 µg/mL rapamycin or paclitaxel combined with cytokine antibody for 48 hours. RESULTS: After incubation of HASMC with ox-LDL, the ratios of cholesterol ester and total cholesterol increased significantly (55.29%) (P<0.01). Lipid staining with Oil Red O showed many lipid vacuoles and red dye particles in the cells. Meanwhile, cell viability and proliferation significantly increased compared with the control. This indicated that HASMC had been transformed into foam cells (P<0.01) while rapamycin or paclitaxel concentrations ≥0.1 µg/mL can significantly decrease the foam cell proliferation (P<0.05 or P<0.01), and 1 µg/mL of rapamycin or paclitaxel appeared the most effective concentration. As for cytokines, rapamycin or paclitaxel concentrations ≥1 ug/mL could significantly increase the level of inflammatory cytokines IL-6 (P<0.05 or P<0.01), which was enhanced with the increase of drug concentration. However, rapamycin or paclitaxel concentrations ≥1 µg/mL could significantly reduce the levels of anti-inflammatory cytokines IL-35 and transforming growth factor beta (TGF-ß) (P<0.05 or P<0.01), which decreased with the increase of drug concentration. In addition, rapamycin or paclitaxel combined with anti-IL-1ß, anti-IL-6, anti- TNF-α or anti-IL-35 had no significant effect on foam cell proliferation compared to the drug alone. However, rapamycin or paclitaxel combined with anti-IL-10 or anti-TGF-ß can significantly enhance foam cell proliferation (P<0.01). In addition, there was no difference in the effects of the same concentrations of rapamycin and paclitaxel on foam cells. CONCLUSION: Although rapamycin or paclitaxel can reduce foam cell proliferation, too high or too low concentrations could decrease effectiveness. In particular, a high dose can induce foam cells to increase inflammatory cytokines secretion, reduce anti-inflammatory cytokines secretion, and thus affect the inhibiting proliferation. For rapamycin- and paclitaxel-eluting stents, this conclusion may explain the clinical observation of in-stent restenosis after percutaneous coronary intervention. DES coated with an appropriate concentration of rapamycin or paclitaxel may, at least to some extent, contribute significantly to reducing incidence of late in-stent restenosis.

Assuntos

Reestenose Coronária , Sirolimo , Proliferação de Células , Reestenose Coronária/induzido quimicamente , Reestenose Coronária/terapia , Citocinas , Células Espumosas , Humanos , Miócitos de Músculo Liso , Paclitaxel/efeitos adversos , Sirolimo/farmacologia , Stents/efeitos adversos

RESUMO

Verruciform xanthoma (VX) is a rare benign lesion of unknown etiology, with a rough or papillary aspect, painless, sessile, well-defined, most lesions do not exceed 2 cm in their largest diameter, the degree of keratinization of the surface influences color, varying white to red, affecting mainly the gingiva and alveolar mucosa, and can also be seen in skin and genital. Herein, we present a report a clinical case of oral verruciform xanthoma in the buccal mucosa associated with the lichen planus lesion, as well as the morphological and immunohistochemical characteristics of the lesion. The clinical diagnostic hypothesis of oral lichen planus of the white reticular lesions on the buccal mucosa and on the tongue was confirmed by histopathology before a subepithelial connective tissue exhibiting intense inflammatory infiltrate in a predominantly lymphocytic band. In contrast, the hypothesis of the verrucous lesion in the left buccal mucosa was leukoplakia, with histopathological evidence showing exophytic and digitiform proliferations with parakeratin plugs between the papillary projections. Subepithelial connective tissue was characterized by macrophages with foamy cytoplasm (xanthoma cells). An immunohistochemical examination was performed, showing positivity for CD68, a macrophage marker, in addition to testing by Schiff's periodic acid (PAS) with diastasis, which was detected the presence of lipids inside these macrophages. The patient is free of recurrences of verruciform xanthoma and is being monitored due to the presence of lesions of oral lichen planus.

Assuntos

Humanos , Feminino , Idoso , Xantomatose/complicações , Líquen Plano Bucal/complicações , Imuno-Histoquímica , Xantomatose/patologia , Líquen Plano Bucal/patologia , Mucosa Bucal/patologia

RESUMO

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

Assuntos

Café , Lipidômica , Ácido Clorogênico , Células Espumosas , Voluntários Saudáveis , Humanos

RESUMO

BACKGROUND: Opsonization, is the molecular mechanism by which target molecules promote interactions with phagocyte cell surface receptors to remove unwanted cells by induced phagocytosis. We designed an in vitro system to demonstrate that this procedure could be driven to eliminate adipocytes, using peptides mimicking regions of the complement protein C3b to promote opsonization and enhance phagocytosis. Two cell lines were used: (1) THP-1 monocytes differentiated to macrophages, expressing the C3b opsonin receptor CR1 in charge of the removal of unwanted coated complexes; (2) 3T3-L1 fibroblasts differentiated to adipocytes, expressing AQP7, to evaluate the potential of peptides to stimulate opsonization. (3) A co-culture of the two cell lines to demonstrate that phagocytosis could be driven to cell withdrawal with high efficiency and specificity. RESULTS: An array of peptides were designed and chemically synthesized p3691 and p3931 joined bound to the CR1 receptor activating phagocytosis (p < 0.033) while p3727 joined the AQP7 protein (p < 0.001) suggesting that opsonization of adipocytes could occur. In the co-culture system p3980 and p3981 increased lipid uptake to 91.2% and 89.0%, respectively, as an indicator of potential adipocyte phagocytosis. CONCLUSIONS: This in vitro model could help understand the receptor­ligand interaction in the withdrawal of unwanted macromolecules in vivo. The adipocyte-phagocytosis discussed may help to control obesity, since peptides of C3b stimulated the CR1 receptor, promoting opsonisation and phagocytosis of lipidcontaining structures, and recognition of AQP7 in the differentiated adipocytes, favored the phagocytic activity of macrophages, robustly supported by the co-culture strategy.

Assuntos

Fagocitose , Proteínas do Sistema Complemento , Adipócitos , Técnicas In Vitro , Proteínas Opsonizantes , Técnicas de Cocultura , Células Espumosas , Macrófagos , Microscopia de Fluorescência

RESUMO

BACKGROUND: Cardiovascular disease is more frequent in menopausal women, which has been related to factor such as weight gain, altered fat distribution, and increased inflammation markers including adipokines (MCP-1, TNF-α, IL-6) and cytokines (IL-1, IL-6, TNF-α) produced by macrophages. In addition to their phagocytic activity, macrophages secrete cytokines and chemokines that induces cell recruitment, which is a process related to vascular damage that favors the formation of atheromatous plaques. Tibolone (Tb) therapy is used to reduce the symptoms of menopause as well as osteoporosis and it has been shown to decreases the risk of fractures. METHODS: To investigate the effect of tibolone in macrophage enzymatic activity, gene expression of cytokines, and its effect on foam cells formation. We use phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 cells. The cells were incubated 24 h and 48 h using pre and post-treatment schemes. We evaluated total ROS determination by NBT assay, expression of cytokines (IL-1ß, IL-6, TNF-α, NOS2, ARG1, TGFß) by RT-qPCR and foam cell formation in THP-1 differentiated macrophages stimulated with PMA. RESULTS: It was observed that the minor levels of total ROS determination were obtained with tibolone at 48 h in post-treatment scheme. Also, in a long term we found decrease the proinflammatory cytokines (IL-1ß, IL-6 and TNF-α). Finally, with treatment for 24 h with P4 y Tb we observed fewer LDL vesicles into macrophages cytoplasm. CONCLUSIONS: These results suggest that tibolone reduces the inflammatory process, also inhibits the foam cells formation; suggesting a possible role in reducing cardiovascular risk.

Assuntos

Citocinas , Lipoproteínas LDL , Espécies Reativas de Oxigênio , Células Espumosas , Humanos , Células THP-1

RESUMO

Leptospirosis is a world-wide zoonotic disease caused by pathogenic Leptospira and can be asymptomatic or can cause clinical signs ranging from influenza-like to multi-organ failure and death in severe cases. While species and strain specificity can play a major role in disease presentation, the hamster is susceptible to most leptospiral infections and is the model of choice for vaccine efficacy testing. During evaluation of blood smears from hamsters challenged with different species and strains of Leptospira, a circulating population of large, mononuclear, lipid-filled cells, most similar to foamy macrophages (FMs), was detected. Circulating FMs were identified by Giemsa staining and verified by scanning and transmission electron microscopy. FMs were found in the circulating blood of all Leptospira-challenged hamsters, indicating that the finding was not species or strain specific, although higher numbers of FMs tended to correlate with severity of disease. The unique finding of circulating FMs in the hamster model of leptospirosis can yield additional insights into the pathogenesis of leptospirosis and other diseases that induce circulating FMs.

RESUMO

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

Assuntos

Aterosclerose , Café , Adulto , Ácido Clorogênico/farmacologia , Células Espumosas , Humanos , Macrófagos , Oxilipinas

RESUMO

BACKGROUND AND AIMS: Hypercholesterolemia and oxidative stress are two of the most important risk factors for atherosclerosis. The aim of the present work was to evaluate mandarin (Citrus reticulata) peel oil (MPO) in cholesterol metabolism and lipid synthesis, and its antioxidant capacity. METHODS AND RESULTS: Incubation of hepatic HepG2 cells with MPO (15-60 µL/L) reduced cholesterogenesis and saponifiable lipid synthesis, demonstrated by [14C]acetate radioactivity assays. These effects were associated with a decrease in a post-squalene reaction of the mevalonate pathway. Molecular docking analyses were carried out using three different scoring functions to examine the cholesterol-lowering property of all the components of MPO against lanosterol synthase. Docking simulations proposed that minor components of MPO monoterpenes, like alpha-farnesene and neryl acetate, as well the major component, limonene and its metabolites, could be partly responsible for the inhibitory effects observed in culture assays. MPO also decreased RAW 264.7 foam cell lipid storage and its CD36 expression, and prevented low-density lipoprotein (LDL) lipid peroxidation. CONCLUSION: These results may imply a potential role of MPO in preventing atherosclerosis by a mechanism involving inhibition of lipid synthesis and storage and the decrease of LDL lipid peroxidation.

Assuntos

Antioxidantes/farmacologia , Aterosclerose/prevenção & controle , Colesterol/metabolismo , Citrus , Dislipidemias/tratamento farmacológico , Células Espumosas/efeitos dos fármacos , Frutas , Hepatócitos/efeitos dos fármacos , Hipolipemiantes/farmacologia , Lipoproteínas LDL/metabolismo , Óleos de Plantas/farmacologia , Animais , Antioxidantes/isolamento & purificação , Aterosclerose/etiologia , Aterosclerose/metabolismo , Antígenos CD36/metabolismo , Citrus/química , Dislipidemias/complicações , Dislipidemias/metabolismo , Células Espumosas/metabolismo , Frutas/química , Células Hep G2 , Hepatócitos/metabolismo , Humanos , Hipolipemiantes/isolamento & purificação , Transferases Intramoleculares/antagonistas & inibidores , Transferases Intramoleculares/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Simulação de Acoplamento Molecular , Óleos de Plantas/isolamento & purificação , Células RAW 264.7

RESUMO

Niemann-Pick type C (NPC), a lysosomal storage disorder, is mainly caused by mutations in the NPC1 gene. Niemann-Pick type C patients and mice show intracellular cholesterol accumulation leading to hepatic failure with increased inflammatory response. The complement cascade, which belongs to the innate immunity response, recognizes danger signals from injured tissues. We aimed to determine whether there is activation of the complement system in the liver of the NPC mouse and to assess the relationship between C3 activation, a final component of the pathway, and NPC liver pathology. Niemann-Pick type C mice showed high levels of C3 staining in the liver which unexpectedly decreased with aging. Using an inducible NPC1 hepatocyte rescue mouse model, we restored NPC1 expression for a short time in young mice. We found C3 positive cells only in non-rescued cells, suggesting that C3 activation in NPC cells is reversible. Then, we studied the effect of C3 ablation on NPC liver damage at two postnatal time points, P56 and P72. Deletion of C3 reduced the presence of hepatic CD68-positive cells at postnatal day 56 and prevented the increase of transaminase levels in the blood of NPC mice. These positive effects were abrogated at P72, indicating that the complement cascade participates only during the early stages of liver damage in NPC mice, and that its inhibition may serve as a new potential therapeutic strategy for the disease.

Assuntos

Complemento C3/metabolismo , Fígado/patologia , Doença de Niemann-Pick Tipo C/imunologia , Envelhecimento/patologia , Animais , Células Espumosas/metabolismo , Células Espumosas/patologia , Camundongos Endogâmicos C57BL

RESUMO

Foam cells are specialized lipid-loaded macrophages derived from monocytes and are a key pathological feature of atherosclerotic lesions. Lysophosphatidylcholine (LPC) is a major lipid component of the plasma membrane with a broad spectrum of proinflammatory activities and plays a key role in atherosclerosis. However, the role of LPC in lipid droplet (LD) biogenesis and the modulation of inflammasome activation is still poorly understood. In the present study, we investigated whether LPC can induce foam cell formation through an analysis of LD biogenesis and determined whether the cell signaling involved in this process is mediated by the inflammasome activation pathway in human endothelial cells and monocytes. Our results showed that LPC induced foam cell formation in both types of cells by increasing LD biogenesis via a NLRP3 inflammasome-dependent pathway. Furthermore, LPC induced pyroptosis in both cells and the activation of the inflammasome with IL-1ß secretion, which was dependent on potassium efflux and lysosomal damage in human monocytes. The present study described the IL-1ß secretion and foam cell formation triggered by LPC via an inflammasome-mediated pathway in human monocytes and endothelial cells. Our results will help improve our understanding of the relationships among LPC, LD biogenesis, and NLRP3 inflammasome activation in the pathogenesis of atherosclerosis.

Assuntos

Células Endoteliais/imunologia , Células Espumosas/imunologia , Inflamassomos/imunologia , Lisofosfatidilcolinas/imunologia , Monócitos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Piroptose , Células Endoteliais/citologia , Células Espumosas/citologia , Humanos , Inflamassomos/genética , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Monócitos/citologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética

RESUMO

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

Assuntos

Biomarcadores/metabolismo , Inflamação/genética , Lipoproteínas LDL/genética , Estresse Oxidativo/genética , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Antígenos CD36/genética , Linhagem Celular , Células Espumosas/metabolismo , Células Espumosas/patologia , Humanos , Inflamação/metabolismo , Inflamação/patologia , Macrófagos/metabolismo , Macrófagos/patologia , Espécies Reativas de Oxigênio/metabolismo , Receptores Depuradores Classe E/genética , Fatores de Processamento de Serina-Arginina/genética

RESUMO

BACKGROUND: In atherosclerotic lesions, cholesterol-laden macrophage foam cells are formed and exposed to M1- and M2-polarizing factors. However, the effects of the polarizing factors on the proinflammatory and the anti-inflammatory potential of foam cells are not known. OBJECTIVE: To investigate the effects of M1- and M2-polarizing factors on the expression of pro- and anti-inflammatory genes in cultured human macrophage foam cells. METHODS AND RESULTS: Human monocytes were differentiated into macrophages in the presence of M-CSF, and then converted into cholesterol-loaded foam cells by incubation with acetylated LDL. The generated macrophages and foam cells were polarized into the M1 phenotype by classical activation with LPS and IFN-γ, or into the M2 phenotype by alternative activation with IL-4. When subjected to the M1-polarizing factors, the macrophages responded by typical upregulation of several key proinflammatory genes (TNFA, IL1B, CXCL8, CCL19, and COX2), while the anti-inflammatory genes (MRC1, CCL17, and IL10) displayed variable responses. The foam cells, again, showed a weaker response to the M1-polarizing factors, as indicated by reduced upregulation of the proinflammatory genes, reduced secretion of TNF-α, and a trend towards lower NF-κB activity. When subjected to alternative M2 polarization, both macrophages and foam cells responded by a typical upregulation of the anti-inflammatory genes, which was of equal magnitude in both cell types. CONCLUSIONS: Conversion of cultured human macrophages into foam cells suppresses their proinflammatory responses to M1-polarizing factors. Thus, in M1-polarizing microenvironments of atherosclerotic lesions, foam cell formation may locally weaken the macrophage-dependent inflammatory component of atherogenesis.

Assuntos

Células Espumosas/citologia , Fator Estimulador de Colônias de Macrófagos/metabolismo , Macrófagos/citologia , Anti-Inflamatórios/química , Aterosclerose/metabolismo , Colesterol/química , Colesterol/metabolismo , Meios de Cultura Livres de Soro , Regulação da Expressão Gênica , Humanos , Inflamação/metabolismo , Interferon gama/metabolismo , Interleucina-1beta/metabolismo , Interleucina-4/metabolismo , Lipopolissacarídeos/química , Macrófagos/metabolismo , NF-kappa B/metabolismo , Fenótipo , Regulação para Cima

RESUMO

El xantoma intraóseo (XIO) es un tumor óseo benigno extremadamente raro. En la histología se caracteriza por presentar macrófagos mononucleares, abundantes células espumosas y células gigantes multinucleadas. Puede aparecer asociado a otras enfermedades (XIO secundario), principalmente a desórdenes lipídicos, o en forma aislada (XIO primario). Los XIO son lesiones líticas expansivas que a menudo se encuentran en pacientes con condiciones hiperlipidémicas. En la mayoría de los casos la evaluación inicial se realiza con radiografía, aunque otros procedimientos pueden ser necesarios para confirmar el diagnóstico. Se presenta el caso de un hombre de 48 años que consultó por lumbalgia con irradiación al miembro inferior derecho e impotencia funcional de 3 meses de evolución. Tenía hallazgos imagenológicos de XIO en el hueso ilíaco derecho, sin hiperlipidemia o lesiones preexistentes. Se llevó a cabo la extirpación total del tumor y el posterior estudio histopatológico de la pieza operatoria confirmó el diagnóstico. El tratamiento resultó exitoso. El objetivo de este artículo es describir los hallazgos clínicos e imagenológicos (radiografía, resonancia magnética, tomografía computada y medicina nuclear) de un XIO primario y su tratamiento. Además, realizamos una breve revisión de la literatura.

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Abstract Intraosseous xanthoma is an extremely rare benign bone tumor. Histology shows mononuclear macrophages, abundant foam cells and multinucleated giant cells. The intraosseous xanthoma may appear associated with other diseases (secondary intraosseous xanthoma), mainly lipid disorders or without an underlying lipid disorder (primary intraosseous xanthoma). The intraosseous xanthoma is a lytic, expansive tumor, often seen in patients with hyperlipidemic conditions. In most cases, the initial evaluation is performed with X-ray, although other procedures may be necessary to confirm the diagnosis. We report the case of a man aged 48, who consulted for back pain radiating to the right leg and functional disability 3 months duration, with imaging findings in the right iliac XIO in the absence of pre-existing injuries or hyperlipidemic conditions, so surgery for total removal of the tumor was performed with histological examination of the surgical specimen, confirming the preoperative diagnosis of XIO. Such treatment resulted curative. The aim of this article is to describe the clinical, imaging findings (RX, MRI, CT, nuclear medicine) and the course of treatment of a committing the iliac primary intraosseous xanthoma a and a normolipidemic patient brief review of the literature.

Assuntos

Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Ósseas/diagnóstico por imagem , Xantomatose/diagnóstico por imagem , Pelve/diagnóstico por imagem , Radiografia , Tomografia Computadorizada por Raios X , Células Espumosas/patologia , Quadril/diagnóstico por imagem

RESUMO

El xantoma intraóseo (XIO) es un tumor óseo benigno extremadamente raro. En la histología se caracteriza por presentar macrófagos mononucleares, abundantes células espumosas y células gigantes multinucleadas. Puede aparecer asociado a otras enfermedades (XIO secundario), principalmente a desórdenes lipídicos, o en forma aislada (XIO primario). Los XIO son lesiones líticas expansivas que a menudo se encuentran en pacientes con condiciones hiperlipidémicas. En la mayoría de los casos la evaluación inicial se realiza con radiografía, aunque otros procedimientos pueden ser necesarios para confirmar el diagnóstico. Se presenta el caso de un hombre de 48 años que consultó por lumbalgia con irradiación al miembro inferior derecho e impotencia funcional de 3 meses de evolución. Tenía hallazgos imagenológicos de XIO en el hueso ilíaco derecho, sin hiperlipidemia o lesiones preexistentes. Se llevó a cabo la extirpación total del tumor y el posterior estudio histopatológico de la pieza operatoria confirmó el diagnóstico. El tratamiento resultó exitoso. El objetivo de este artículo es describir los hallazgos clínicos e imagenológicos (radiografía, resonancia magnética, tomografía computada y medicina nuclear) de un XIO primario y su tratamiento. Además, realizamos una breve revisión de la literatura.(AU)

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Abstract Intraosseous xanthoma is an extremely rare benign bone tumor. Histology shows mononuclear macrophages, abundant foam cells and multinucleated giant cells. The intraosseous xanthoma may appear associated with other diseases (secondary intraosseous xanthoma), mainly lipid disorders or without an underlying lipid disorder (primary intraosseous xanthoma). The intraosseous xanthoma is a lytic, expansive tumor, often seen in patients with hyperlipidemic conditions. In most cases, the initial evaluation is performed with X-ray, although other procedures may be necessary to confirm the diagnosis. We report the case of a man aged 48, who consulted for back pain radiating to the right leg and functional disability 3 months duration, with imaging findings in the right iliac XIO in the absence of pre-existing injuries or hyperlipidemic conditions, so surgery for total removal of the tumor was performed with histological examination of the surgical specimen, confirming the preoperative diagnosis of XIO. Such treatment resulted curative. The aim of this article is to describe the clinical, imaging findings (RX, MRI, CT, nuclear medicine) and the course of treatment of a committing the iliac primary intraosseous xanthoma a and a normolipidemic patient brief review of the literature.(AU)

RESUMO

To establish the etiological relationship and the appearance of foamy macrophages in the liver of cattle from tropical regions of Brazil, liver samples from the files of the Pathology Section of Embrapa-Projeto Sanidade Animal, Rio de Janeiro, were reviewed. A total of 55 liver samples of cattle which died from different causes between 1970 and 1991 were reexamined. Only samples of animals which grazed known pastures were reviewed. Foamy macrophages were not seen in the samples from 1970 to 1975, although 40 samples (72%) were from this period. Foamy macrophages were observed from 1976 on, coinciding with the introduction of Brachiaria decumbens from Australian seeds into Brazil. Some samples were from cattle with histories of photosensitization, which were at that time attributed to Pithomyces chartarum. The results of this study indicate that the liver changes are related to prolonged ingestion of Brachiaria spp.

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Com o objetivo de estabelecer uma relação etiológica e caracterizar, cronologicamente, o aparecimento de macrófagos espumosos (foam cells), comuns em fígados de bovinos oriundos das regiões de clima tropical do Brasil, foram reexaminados cortes histológicos de fígado de bovinos dos arquivos do Setor de Anatomia Patológica da Embrapa-Projeto Sanidade Animal, RJ. O material utilizado provinha de investigações sobre causas de mortandades em bovinos nas regiões Norte, Centro-Oeste e Sudeste do Brasil, realizadas de 1970 a 1991. Foram estudados 55 fígados de bovinos afetados por enfermidades variadas. Somente foram usados casos em que o tipo de pastagem era conhecido. Essa alteração não foi encontrada de 1970 até o final de 1975, embora 40 amostras (72,7%) tenham sido coletadas nesse período. A presença de macrófagos espumosos, observada a partir de 1976, coincidiu com a introdução da gramínea Brachiaria decumbens var. australiana no Brasil. Algumas amostras eram provenientes de bovinos que apresentaram histórico de fotossensibilização, na época atribuída ao fungo Pithomyces chartarum. Os achados indicam que essas alterações hepáticas são relacionadas com a ingestão de Brachiaria spp.