RESUMO
Left ventricular (LV) remodeling after myocardial infarction constitutes the structural basis for ventricular dysfunction and heart failure. The characterization underlying the expression of lipoprotein receptors in cardiac dysfunction is scarcely explored. The aim of this study was to analyze the status of lipoprotein receptors on the infarcted and noninfarcted areas of LV and to verify whether nanoparticles that mimic the lipid structure of low-density lipoprotein (LDL) and have the ability to bind to LDL receptors (LDE) are taken up more avidly by the noninfarcted LV. 13 male Wistar rats with left coronary artery ligation (myocardial infarction [MI]) and 12 animals with SHAM operation (SHAM) were used in this study. 6 weeks after the procedure, the quantification of low-density lipoprotein receptor (LDLR), LDL receptor-related protein 1 (LRP1), scavenger receptor-class B type I (SR-BI) lipoprotein receptors, and PCNA proliferation marker, and tissue uptake of radioactively labeled LDE were performed. Immunohistochemistry and Western blot analysis showed that LDLR, LRP1, SR-BI, and PCNA, expression in infarcted area of MI was remarkably higher than SHAM and noninfarcted subendocardial (SEN) and interstitial (INT) areas. In addition, in SEN noninfarcted area of MI, the presence of LDLR was about threefold higher than in SHAM SEN and INT noninfarcted areas. The LDE uptake of noninfarcted LV of MI group was about 30% greater than that of SHAM group. In conclusion, these findings regarding the status of lipoprotein receptors after MI induction could help to establish mechanisms on myocardial repairing. In conclusion, infarcted rats with LV dysfunction showed increased expression of lipoprotein receptors mainly in the infarcted area.
Assuntos
Infarto do Miocárdio/genética , Receptores de Lipoproteínas/genética , Disfunção Ventricular Esquerda/genética , Animais , Perfilação da Expressão Gênica , Ketamina , Masculino , Infarto do Miocárdio/induzido quimicamente , Infarto do Miocárdio/metabolismo , Ratos , Ratos Wistar , Receptores de Lipoproteínas/metabolismo , Disfunção Ventricular Esquerda/induzido quimicamente , Disfunção Ventricular Esquerda/metabolismo , XilazinaRESUMO
OBJECTIVES: To test the toxicity and antitumoral activity of the compound N-oleyl-daunorubicin (oDNR) with a cholesterol-rich nanoemulsion (LDE) formulation. METHODS: LDE-oDNR was prepared by high-pressure homogenisation of lipid mixtures. B16F10 melanoma cells and NIH/3T3 fibroblasts were used for cytotoxicity tests. The maximum tolerated dose (MTD) of both commercial and LDE-oDNR was determined in mice, and melanoma-bearing mice were used for the antitumoral activity tests. KEY FINDINGS: CC50 for LDE-oDNR and DNR in melanoma cells were 200 µm and 15 µm, respectively, but LDE-oDNR was less toxic against fibroblasts than DNR. MTD for LDE-oDNR was 65-fold higher than commercial DNR. In tumour-bearing mice, LDE-oDNR (7.5 µmol/kg) reduced tumour growth by 59 ± 2%, whereas the reduction by DNR was only 23 ± 2%. LDE-oDNR increased survival rates (P < 0.05), which was not achieved by DNR treatment. The number of mice with metastasis was only 30% in LDE-oDNR-treated mice, compared with 82% under DNR treatment. By flow cytometry, there were 9% viable cells in tumours of animals treated with LDE-oDNR compared with 27% in DNR-treated animals. Less haematological toxicity was observed in LDE-oDNR-treated mice. CONCLUSIONS: Compared with DNR, LDE-oDNR improved tumour growth inhibition and survival rates with pronouncedly less toxicity, and thus may become a new tool for cancer treatment.
Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Colesterol/química , Daunorrubicina/análogos & derivados , Daunorrubicina/uso terapêutico , Portadores de Fármacos/química , Melanoma Experimental/tratamento farmacológico , Nanoestruturas/química , Ácidos Oleicos/uso terapêutico , Receptores de LDL/metabolismo , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Daunorrubicina/administração & dosagem , Daunorrubicina/toxicidade , Estabilidade de Medicamentos , Emulsões , Masculino , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Estrutura Molecular , Transplante de Neoplasias , Ácidos Oleicos/administração & dosagem , Ácidos Oleicos/toxicidade , Tamanho da Partícula , Ligação Proteica , Testes de Toxicidade AgudaRESUMO
PURPOSE: Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. METHODS: Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, or cholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated. RESULTS: It was shown that cholesteryl stearate nanoemulsions had the greatest particle size and all three nanoemulsions were stable during the 237-day observation period. The pH of the three nanoemulsion preparations tended to decrease over time, but the decrease in pH of cholesteryl stearate was smaller than that of cholesteryl oleate and cholesteryl linoleate. Lipoperoxidation was greater in cholesteryl linoleate than in cholesteryl oleate and cholesteryl stearate. After four hours' incubation of human umbilical vein endothelial cells (HUVEC) with nanoemulsions, peroxidation was minimal in the presence of cholesteryl oleate and more pronounced with cholesteryl linoleate and cholesteryl stearate. In contrast, macrophage incubates showed the highest peroxidation rates with cholesteryl oleate. Cholesteryl linoleate induced the highest cell peroxidation rates, except in macrophages. Uptake of cholesteryl oleate nanoemulsion by HUVEC and fibroblasts was greater than that of cholesteryl linoleate and cholesteryl stearate. Uptake of the three nanoemulsions by monocytes was equal. Uptake of cholesteryl oleate and cholesteryl linoleate by macrophages was negligible, but macrophage uptake of cholesteryl stearate was higher. In H292 tumor cells, cholesteryl oleate showed the highest uptakes. HUVEC showed higher survival rates when incubated with cholesteryl stearate and smaller survival with cholesteryl linoleate. H292 survival was greater with cholesteryl stearate. CONCLUSION: Although all three nanoemulsion types were stable for a long period, considerable differences were observed in size, oxidation status, and cell survival and nanoemulsion uptake in all tested cell lines. Those differences may be helpful in protocol planning and interpretation of data from experiments with lipid nanoemulsions.
Assuntos
Ésteres do Colesterol/química , Portadores de Fármacos/química , Nanoestruturas/química , Transporte Biológico Ativo , Sobrevivência Celular , Células Cultivadas , Sistemas de Liberação de Medicamentos/métodos , Estabilidade de Medicamentos , Emulsões/química , Humanos , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos , Nanomedicina , Tamanho da PartículaRESUMO
Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, orcholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated.It was shown that cholesteryl stearate nanoemulsions had the greatest particlesize and all three nanoemulsions were stable during the 237-day observation period...