Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Más filtros











Intervalo de año de publicación
1.
Cancers (Basel) ; 14(6)2022 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-35326743

RESUMEN

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Patients with AML harboring a constitutively active internal tandem duplication mutation (ITDMUT) in the FMS-like kinase tyrosine kinase (FLT3) receptor generally have a poor prognosis. Several tyrosine kinase/FLT3 inhibitors have been developed and tested clinically, but very few (midostaurin and gilteritinib) have thus far been FDA/EMA-approved for patients with newly diagnosed or relapse/refractory FLT3-ITDMUT AML. Disappointingly, clinical responses are commonly partial or not durable, highlighting the need for new molecules targeting FLT3-ITDMUT AML. Here, we tested EC-70124, a hybrid indolocarbazole analog from the same chemical space as midostaurin with a potent and selective inhibitory effect on FLT3. In vitro, EC-70124 exerted a robust and specific antileukemia activity against FLT3-ITDMUT AML primary cells and cell lines with respect to cytotoxicity, CFU capacity, apoptosis and cell cycle while sparing healthy hematopoietic (stem/progenitor) cells. We also analyzed its efficacy in vivo as monotherapy using two different xenograft models: an aggressive and systemic model based on MOLM-13 cells and a patient-derived xenograft model. Orally disposable EC-70124 exerted a potent inhibitory effect on the growth of FLT3-ITDMUT AML cells, delaying disease progression and debulking the leukemia. Collectively, our findings show that EC-70124 is a promising and safe agent for the treatment of AML with FLT3-ITDMUT.

2.
Bioorg Chem ; 112: 104859, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33836453

RESUMEN

A novel series of enantiopure naphthalimide-cycloalkanediamine conjugates were designed, synthetized and evaluated for in vitro cytotoxicity against human colon adenocarcinoma (LoVo), human lung adenocarcinoma (A549), human cervical carcinoma (Hela) and human promyelocytic leukemia cell lines (HL-60). The cytotoxicity of the compounds was highly dependent on size and relative stereochemistry of the cycloalkyl ring as well as length of the spacer. By contrast, any kind of enantioselection was observed for each pair of enantiomers. Flow cytometric analysis indicated that compounds 22 and 23 could effectively induce G2/M arrest in the four previous cell lines despite a mild apoptotic effect.


Asunto(s)
Antineoplásicos/farmacología , Cicloparafinas/farmacología , Diaminas/farmacología , Diseño de Fármacos , Naftalimidas/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Cicloparafinas/química , Diaminas/química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Estructura Molecular , Naftalimidas/química , Relación Estructura-Actividad
3.
Angew Chem Int Ed Engl ; 60(24): 13536-13541, 2021 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-33768597

RESUMEN

Brasilicardin A (1) consists of an unusual anti/syn/anti-perhydrophenanthrene skeleton with a carbohydrate side chain and an amino acid moiety. It exhibits potent immunosuppressive activity, yet its mode of action differs from standard drugs that are currently in use. Further pre-clinical evaluation of this promising, biologically active natural product is hampered by restricted access to the ready material, as its synthesis requires both a low-yielding fermentation process using a pathogenic organism and an elaborate, multi-step total synthesis. Our semi-synthetic approach included a) the heterologous expression of the brasilicardin A gene cluster in different non-pathogenic bacterial strains producing brasilicardin A aglycone (5) in excellent yield and b) the chemical transformation of the aglycone 5 into the trifluoroacetic acid salt of brasilicardin A (1 a) via a short and straightforward five-steps synthetic route. Additionally, we report the first preclinical data for brasilicardin A.


Asunto(s)
Aminoglicósidos/metabolismo , Ingeniería Genética , Inmunosupresores/síntesis química , Transferasas Alquil y Aril/genética , Aminoglicósidos/síntesis química , Aminoglicósidos/química , Aminoglicósidos/farmacología , Animales , Productos Biológicos/síntesis química , Productos Biológicos/química , Productos Biológicos/metabolismo , Productos Biológicos/farmacología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Inmunosupresores/química , Inmunosupresores/metabolismo , Inmunosupresores/farmacología , Ratones , Plásmidos/genética , Plásmidos/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Terpenos/química
4.
Eur Urol Oncol ; 2(4): 415-424, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31277777

RESUMEN

BACKGROUND: The TMPRSS2-ERG gene fusion is the most frequent genetic rearrangement in prostate cancers and results in broad transcriptional reprogramming and major phenotypic changes. Interaction and cooperation of ERG and SP1 may be instrumental in sustaining the tumorigenic and metastatic phenotype and could represent a potential vulnerability in ERG fusion-positive tumors. OBJECTIVE: To test the activity of EC-8042, a compound able to block SP1, in cellular and mouse models of ERG-positive prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: We evaluated the activity of EC-8042 in cell cultures and ERG/PTEN transgenic/knockout mice that provide reliable models for testing novel therapeutics in this specific disease context. Using a new protocol to generate tumor spheroids from ERG/PTEN mice, we also examined the effects of EC-8042 on tumor-propagating stem-like cancer cells with high self-renewal and tumorigenic capabilities. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The efficacy of EC-8042 was determined by measuring the proliferative capacity and target gene expression in cell cultures, invasive and metastatic capabilities in chick chorioallantoic membrane assays, and tumor development in mice. Significance was determined using statistical test. RESULTS AND LIMITATIONS: EC-8042 blocked transcription of ERG-regulated genes and reverted the invasive and metastatic phenotype of VCaP cells. EC-8042 blocked the expansion of stem-like tumor cells in tumor spheroids from VCaP cells and mouse-derived tumors. In ERG/PTEN mice, systemic treatment with EC-8042 inhibited ERG-regulated gene transcription, tumor progression, and tumor-propagating stem-like tumor cells. CONCLUSIONS: Our data support clinical testing of EC-8042 for the treatment of ERG-positive prostate cancer in precision medicine approaches. PATIENT SUMMARY: In this study, EC-8042, a novel compound with a favorable pharmacological and toxicological profile, exhibited relevant activity in cell cultures and in vivo in a genetically engineered mouse model that closely recapitulates the features of clinically aggressive ERG-positive prostate cancer. Our data indicate that further evaluation of EC-8042 in clinical trials is warranted.


Asunto(s)
Plicamicina/análogos & derivados , Neoplasias de la Próstata/genética , Factor de Transcripción Sp1/antagonistas & inhibidores , Regulador Transcripcional ERG/genética , Animales , Línea Celular Tumoral , Humanos , Masculino , Ratones Transgénicos , Células Madre Neoplásicas , Fosfohidrolasa PTEN/genética , Plicamicina/farmacología , Plicamicina/uso terapéutico , Neoplasias de la Próstata/tratamiento farmacológico
5.
Int J Cancer ; 145(1): 254-266, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-30575954

RESUMEN

Cytotoxic drugs like doxorubicin remain as the most utilized agents in sarcoma treatment. However, advanced sarcomas are often resistant, thus stressing the need for new therapies aimed to overcome this resistance. Multikinase inhibitors provide an efficient way to target several pro-tumorigenic pathways using a single agent and may constitute a valuable strategy in the treatment of sarcomas, which frequently show an aberrant activation of pro-tumoral kinases. Therefore, we studied the antitumor activity of EC-70124, an indolocarbazole analog that have demonstrated a robust ability to inhibit a wide range of pro-survival kinases. Evaluation of the phospho-kinase profile in cell-of-origin sarcoma models and/or sarcoma primary cell lines evidenced that PI3K/AKT/mTOR, JAK/STAT or SRC were among the most highly activated pathways. In striking contrast with the structurally related drug midostaurin, EC-70124 efficiently prevented the phosphorylation of these targets and robustly inhibited proliferation through a mechanism associated to the induction of DNA damage, cell cycle arrest and apoptosis. In addition, EC-70124 was able to partially reduce tumor growth in vivo. Importantly, this compound inhibited the expression and activity of ABC efflux pumps involved in drug resistance. In line with this ability, we found that the combined treatment of EC-70124 with doxorubicin resulted in a synergistic cytotoxic effect in vitro and an increased antitumor activity of this cytotoxic drug in vivo. Altogether, these results uncover the capability of the novel multikinase inhibitor EC-70124 to counteract drug resistance in sarcoma and highlight its therapeutic potential when combined with current treatments.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Carbazoles/farmacología , Doxorrubicina/farmacología , Sarcoma/tratamiento farmacológico , Transportadoras de Casetes de Unión a ATP/antagonistas & inhibidores , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Doxorrubicina/administración & dosificación , Sinergismo Farmacológico , Femenino , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Inhibidores de Proteínas Quinasas/administración & dosificación , Inhibidores de Proteínas Quinasas/farmacología , Sarcoma/enzimología , Transducción de Señal/efectos de los fármacos , Estaurosporina/análogos & derivados , Estaurosporina/farmacología , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
6.
Oncoimmunology ; 7(9): e1477460, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30228947

RESUMEN

Treatment for acute myeloid leukemia (AML) remains suboptimal and many patients remain refractory or relapse upon standard chemotherapy based on nucleoside analogs plus anthracyclines. The crosstalk between AML cells and the BM stroma is a major mechanism underlying therapy resistance in AML. Lenalidomide and pomalidomide, a new generation immunomodulatory drugs (IMiDs), possess pleiotropic anti-leukemic properties including potent immune-modulating effects and are commonly used in hematological malignances associated with intrinsic dysfunctional BM such as myelodysplastic syndromes and multiple myeloma. Whether IMiDs may improve the efficacy of current standard treatment in AML remains understudied. Here, we have exploited in vitro and in vivo preclinical AML models to analyze whether IMiDs potentiate the efficacy of AraC/Idarubicin-based standard AML chemotherapy by interfering with the BM stroma-mediated chemoresistance. We report that IMiDs do not exert cytotoxic effects on either non-del5q/5q- AML cells nor BM-MSCs, but they enhance the immunomodulatory properties of BM-MSCs. When combined with AraC/Idarubicin, IMiDs fail to circumvent BM stroma-mediated resistance of non-del5q/5q- AML cells in vitro and in vivo but induce robust extramedullary mobilization of AML cells. When administered as a single agent, lenalidomide specifically mobilizes non-del5q/5q- AML cells, but not healthy CD34+ cells, to peripheral blood (PB) through specific downregulation of CXCR4 in AML blasts. Global gene expression profiling supports a migratory/mobilization gene signature in lenalidomide-treated non-del5q/5q- AML blasts but not in CD34+ cells. Collectively, IMiDs mobilize non-del5q/5q- AML blasts to PB through CXCR4 downregulation, but fail to potentiate AraC/Idarubicin activity in preclinical models of non-del5q/5q- AML.

7.
Mol Cancer Ther ; 17(3): 614-624, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29339551

RESUMEN

Internal tandem duplication (ITD) or tyrosine kinase domain mutations of FLT3 is the most frequent genetic alteration in acute myelogenous leukemia (AML) and are associated with poor disease outcome. Despite considerable efforts to develop single-target FLT3 drugs, so far, the most promising clinical response has been achieved using the multikinase inhibitor midostaurin. Here, we explore the activity of the indolocarbazole EC-70124, from the same chemical space as midostaurin, in preclinical models of AML, focusing on those bearing FLT3-ITD mutations. EC-70124 potently inhibits wild-type and mutant FLT3, and also other important kinases such as PIM kinases. EC-70124 inhibits proliferation of AML cell lines, inducing cell-cycle arrest and apoptosis. EC-70124 is orally bioavailable and displays higher metabolic stability and lower human protein plasma binding compared with midostaurin. Both in vitro and in vivo pharmacodynamic analyses demonstrate inhibition of FLT3-STAT5, Akt-mTOR-S6, and PIM-BAD pathways. Oral administration of EC-70124 in FLT3-ITD xenograft models demonstrates high efficacy, reaching complete tumor regression. Ex vivo, EC-70124 impaired cell viability in leukemic blasts, especially from FLT3-ITD patients. Our results demonstrate the ability of EC-70124 to reduce proliferation and induce cell death in AML cell lines, patient-derived leukemic blast and xenograft animal models, reaching best results in FLT3 mutants that carry other molecular pathways' alterations. Thus, its unique inhibition profile warrants EC-70124 as a promising agent for AML treatment based on its ability to interfere the complex oncogenic events activated in AML at several levels. Mol Cancer Ther; 17(3); 614-24. ©2018 AACR.


Asunto(s)
Carbazoles/farmacología , Indoles/farmacología , Leucemia Mieloide/tratamiento farmacológico , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Ensayos Antitumor por Modelo de Xenoinjerto , Tirosina Quinasa 3 Similar a fms/antagonistas & inhibidores , Enfermedad Aguda , Animales , Disponibilidad Biológica , Células CACO-2 , Carbazoles/farmacocinética , Carbazoles/uso terapéutico , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Femenino , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Células HL-60 , Humanos , Indoles/farmacocinética , Indoles/uso terapéutico , Leucemia Mieloide/genética , Leucemia Mieloide/metabolismo , Ratones SCID , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Proto-Oncogénicas c-pim-1/genética , Proteínas Proto-Oncogénicas c-pim-1/metabolismo , Células THP-1 , Tirosina Quinasa 3 Similar a fms/metabolismo
8.
Mol Cancer Ther ; 15(5): 806-18, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26826115

RESUMEN

Cancer stem cells (CSC) contribute to disease progression and treatment failure in prostate cancer because of their intrinsic resistance to current therapies. The transcription factors NF-κB and STAT3 are frequently activated in advanced prostate cancer and sustain expansion of prostate CSCs. EC-70124 is a novel chimeric indolocarbazole compound generated by metabolic engineering of the biosynthetic pathways of glycosylated indolocarbazoles, such as staurosporine and rebeccamycin. In vitro kinome analyses revealed that EC-70124 acted as a multikinase inhibitor with potent activity against IKKß and JAK2. In this study, we show that EC-70124 blocked concomitantly NF-κB and STAT3 in prostate cancer cells and particularly prostate CSCs, which exhibited overactivation of these transcription factors. Phosphorylation of IkB and STAT3 (Tyr705), the immediate targets of IKKß and JAK2, respectively, was rapidly inhibited in vitro by EC-70124 at concentrations that were well below plasma levels in mice. Furthermore, the drug blocked activation of NF-κB and STAT3 reporters and suppressed transcription of their target genes. Treatment with EC-70124 impaired proliferation and colony formation in vitro and delayed development of prostate tumor xenografts. Notably, EC-70124 had profound effects on the prostate CSC subpopulation both in vitro and in vivo Thus, EC-70124 is a potent inhibitor of the NF-κB and STAT3 signaling pathways and blocked tumor growth and maintenance of prostate CSCs. EC-70124 may provide the basis for developing new therapeutic strategies that combine agents directed to the CSC component and the bulk tumor cell population for treatment of advanced prostate cancer. Mol Cancer Ther; 15(5); 806-18. ©2016 AACR.


Asunto(s)
Transformación Celular Neoplásica/efectos de los fármacos , Transformación Celular Neoplásica/metabolismo , FN-kappa B/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/metabolismo , Neoplasias de la Próstata/etiología , Neoplasias de la Próstata/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Factor de Transcripción STAT3/metabolismo , Animales , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Glicosilación , Humanos , Masculino , Ratones , Neoplasias de la Próstata/patología , Transducción de Señal/efectos de los fármacos , Carga Tumoral , Ensayos Antitumor por Modelo de Xenoinjerto
9.
J Biol Chem ; 290(24): 14852-65, 2015 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-25918169

RESUMEN

Low density lipoprotein receptor-related protein (LRP1) mediates the internalization of aggregated LDL (AgLDL), which in turn increases the expression of LRP1 in human vascular smooth muscle cells (hVSMCs). This positive feedback mechanism is thus highly efficient to promote the formation of hVSMC foam cells, a crucial vascular component determining the susceptibility of atherosclerotic plaque to rupture. Here we have determined the LRP1 domains involved in AgLDL recognition with the aim of specifically blocking AgLDL internalization in hVSMCs. The capacity of fluorescently labeled AgLDL to bind to functional LRP1 clusters was tested in a receptor-ligand fluorometric assay made by immobilizing soluble LRP1 "minireceptors" (sLRP1-II, sLRP1-III, and sLRP1-IV) recombinantly expressed in CHO cells. This assay showed that AgLDL binds to cluster II. We predicted three well exposed and potentially immunogenic peptides in the CR7-CR9 domains of this cluster (termed P1 (Cys(1051)-Glu(1066)), P2 (Asp(1090)-Cys(1104)), and P3 (Gly(1127)-Cys(1140))). AgLDL, but not native LDL, bound specifically and tightly to P3-coated wells. Rabbit polyclonal antibodies raised against P3 prevented AgLDL uptake by hVSMCs and were almost twice as effective as anti-P1 and anti-P2 Abs in reducing intracellular cholesteryl ester accumulation. Moreover, anti-P3 Abs efficiently prevented AgLDL-induced LRP1 up-regulation and counteracted the down-regulatory effect of AgLDL on hVSMC migration. In conclusion, domain CR9 appears to be critical for LRP1-mediated AgLDL binding and internalization in hVSMCs. Our results open new avenues for an innovative anti-VSMC foam cell-based strategy for the treatment of vascular lipid deposition in atherosclerosis.


Asunto(s)
Células Espumosas/citología , Lipoproteínas LDL/fisiología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/fisiología , Músculo Liso Vascular/citología , Secuencia de Aminoácidos , Animales , Células CHO , Células Cultivadas , Cricetinae , Cricetulus , Humanos , Ligandos , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/química , Datos de Secuencia Molecular , Reacción en Cadena en Tiempo Real de la Polimerasa , Homología de Secuencia de Aminoácido
10.
Clín. investig. arterioscler. (Ed. impr.) ; 24(3): 115-130, mayo-jun. 2012. ilus, tab
Artículo en Español | IBECS | ID: ibc-105085

RESUMEN

Introducción La hipoxia se considera un factor clave en la progresión de las lesiones ateroscleróticas. El low density lipoprotein receptor-related protein-1 (LRP1) juega un papel fundamental en la vasculatura. El propósito de este estudio fue investigar el efecto de la hipoxia en la expresión y la función del LRP1 en células musculares lisas vasculares (CMLV) y el papel del factor de transcripción inducible por la hipoxia 1 alfa (..) (AU)


Objective Hypoxia is considered a key factor in the progression of atherosclerotic lesions. Low density lipoprotein receptor-related protein 1 (LRP1) plays a pivotal role in the vasculature. The aims of this study were to investigate the effect of hypoxia on LRP1 expression and function in vascular smooth muscle cells (VSMC) and the role of hypoxia-inducible factor alpha (..) (AU)


Asunto(s)
Humanos , Hipoxia de la Célula/fisiología , Aterosclerosis/fisiopatología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/fisiología , Músculo Liso Vascular/fisiología , Esterol Esterasa , Lipoproteínas LDL , Subunidad alfa del Factor 1 Inducible por Hipoxia/fisiología
11.
Arterioscler Thromb Vasc Biol ; 31(6): 1411-20, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21454812

RESUMEN

OBJECTIVE: Hypoxia is considered a key factor in the progression of atherosclerotic lesions. Low-density lipoprotein receptor-related protein (LRP1) plays a pivotal role in the vasculature. The aim of this study was to investigate the effect of hypoxia on LRP1 expression and function in vascular smooth muscle cells (VSMC) and the role of hypoxia-inducible factor-α (HIF-1α). METHODS AND RESULTS: Real-time polymerase chain reaction and Western blot analysis demonstrated that hypoxia (1% O(2)) time-dependently induced LRP1 mRNA (maximum levels at 1 to 2 hours) and protein expression (maximum levels at 12 to 24 hours). The delayed hypoxic upregulation of LRP1 protein versus mRNA may be explained by the long half-life of LRP1 protein. Luciferase assays demonstrated that hypoxia and HIF-1α overaccumulation induced LRP1 promoter activity and that 2 consensus hypoxia response element sites located at -1072/-1069 and -695/-692 participate in the induction. Chromatin immunoprecipitation showed the in vivo binding of HIF-1α to LRP1 promoter in hypoxic VSMC. Hypoxia effects on LRP1 protein expression were functionally translated into an increased cholesteryl ester (CE) accumulation from aggregated low-density lipoprotein (agLDL) uptake. The blockade of HIF-1α expression inhibited the upregulatory effect of hypoxia on LRP1 expression and agLDL-derived intracellular CE overaccumulation, suggesting that both LRP1 overexpression and CE overaccumulation in hypoxic vascular cells are dependent on HIF-1α. Immunohistochemical analysis showed the colocalization of LRP1 and HIF-1α in vascular cells of human advanced atherosclerotic plaques. CONCLUSION: Hypoxia upregulates LRP1 expression and agLDL-derived intracellular CE accumulation in human VSMC through HIF-1α induction.


Asunto(s)
Antígenos CD/genética , Hipoxia de la Célula , Subunidad alfa del Factor 1 Inducible por Hipoxia/fisiología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Aterosclerosis/metabolismo , Células Cultivadas , Ésteres del Colesterol/metabolismo , Regulación de la Expresión Génica , Humanos , Lipoproteínas LDL/metabolismo , Músculo Liso Vascular/citología , Regiones Promotoras Genéticas , ARN Mensajero/análisis , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/análisis , Proteína 2 de Unión a Elementos Reguladores de Esteroles/análisis
12.
Cardiovasc Res ; 78(3): 581-9, 2008 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-18281370

RESUMEN

AIMS: Hypertension is a risk factor for atherothrombotic vascular events. Angiotensin II (Ang II), one of the main vasoactive hormones of the renin-angiotensin system, has been associated with the development and progression of atherosclerosis. However, it is not fully known how Ang II contributes to lipid-enriched atherosclerotic lesion formation. In human vascular smooth muscle cells (VSMC), low density lipoprotein (LDL) receptor-related protein (LRP1) internalizes cholesteryl esters (CE) from extracellular matrix-bound aggregated LDL (agLDL). The aim of this study was to investigate the effect of Ang II on LRP1 expression and function in VSMC. METHODS AND RESULTS: Here, we report for the first time that Ang II induces the upregulation of LRP1 expression in VSMC. Ang II (1 microM) induced maximal LRP1 mRNA expression at 12 h and maximal protein overexpression (by 4.10-fold) at 24 h in cultured human VSMC. Ang II effects were functionally translated into an increased CE accumulation from agLDL uptake (by two-fold at 50 microg/mL) that was prevented by the LRP1 ligand lactoferrin and by siRNA-LRP1 treatment. Ang II-LRP1 upregulation and excess CE accumulation from agLDL were prevented by losartan (an AT1 blocker) but not by PD123319 (a specific AT2 blocker). Additionally, in a normolipidaemic rat model, Ang II infusion produced a significant increase in aortic LRP1 expression and lipid infiltration in the arterial intima. CONCLUSION: The in vitro and in vivo data reported here indicate that Ang II upregulates LRP1 receptor expression and LRP1-mediated aggregated LDL uptake in vascular cells.


Asunto(s)
Angiotensina II/metabolismo , Aterosclerosis/etiología , Hipertensión/metabolismo , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Músculo Liso Vascular/metabolismo , Angiotensina II/administración & dosificación , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Bloqueadores del Receptor Tipo 2 de Angiotensina II , Animales , Aterosclerosis/metabolismo , Células Cultivadas , Ésteres del Colesterol/metabolismo , Modelos Animales de Enfermedad , Humanos , Hipertensión/inducido químicamente , Hipertensión/complicaciones , Imidazoles/farmacología , Lactoferrina/metabolismo , Losartán/farmacología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Masculino , Músculo Liso Vascular/efectos de los fármacos , Piridinas/farmacología , Interferencia de ARN , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Wistar , Receptor de Angiotensina Tipo 1/efectos de los fármacos , Receptor de Angiotensina Tipo 1/metabolismo , Receptor de Angiotensina Tipo 2/metabolismo , Factores de Tiempo , Regulación hacia Arriba
13.
Arterioscler Thromb Vasc Biol ; 26(1): 117-23, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16254205

RESUMEN

OBJECTIVE: Low-density lipoprotein (LDL) receptor-related protein (LRP1) mediates the internalization of aggregated LDL (agLDL)-LDL trapped in the arterial intima bound to proteoglycans-into human vascular smooth muscle cells (VSMC). LRP1-mediated agLDL uptake induces high-intracellular cholesteryl ester (CE) accumulation. The aim of this study was to characterize the mechanism of agLDL internalization in human VSMC. METHODS AND RESULTS: The lipidic component of LDL was labeled with [3H] and the apolipoprotein component with [(125)I]. We found that >90% of intracellular CE derived from agLDL uptake was not associated with apoB100 degradation but was selectively taken up from agLDL. The inhibition of LRP1 expression by small interfering RNA treatment led to a decrease of 80+/-0.05% in agLDL-CE selective uptake. AgLDL induced intracellular CE accumulation without a concomitant CE synthesis. Cytosolic and cytoskeletal proteins were not required for CE transport. Electron and confocal microscopy experiments indicate that CE derived from agLDL accumulated in adipophilin-stained lipid droplets that were not removable by high-density lipoprotein. CONCLUSIONS: Taken together, these results demonstrate that LRP1 mediates the selective uptake of CE from agLDL and that CE derived from agLDL is not intracellularly processed but stored in lipid droplets in human VSMC.


Asunto(s)
Ésteres del Colesterol/farmacocinética , LDL-Colesterol/farmacocinética , Vasos Coronarios/metabolismo , Músculo Liso Vascular/metabolismo , Antimaláricos/farmacología , Apolipoproteína B-100 , Apolipoproteínas B/farmacocinética , Células Cultivadas , Cloroquina/farmacología , HDL-Colesterol/metabolismo , Vasos Coronarios/citología , Citoesqueleto/efectos de los fármacos , Citoesqueleto/metabolismo , Inhibidores Enzimáticos/farmacología , Humanos , Radioisótopos de Yodo , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Músculo Liso Vascular/citología , Fagocitosis/efectos de los fármacos , Fagocitosis/fisiología , Inhibidores de Proteínas Quinasas/farmacología , Tritio
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA