RESUMO
The purpose of this work is to investigate the protein kinase inhibitory activity of constituents from Acacia auriculiformis stem bark. Column chromatography and NMR spectroscopy were used to purify and characterize betulin from an ethyl acetate soluble fraction of acacia bark. Betulin, a known inducer of apoptosis, was screened against a panel of 16 disease-related protein kinases. Betulin was shown to inhibit Abelson murine leukemia viral oncogene homolog 1 (ABL1) kinase, casein kinase 1ε (CK1ε), glycogen synthase kinase 3α/ß (GSK-3 α/ß), Janus kinase 3 (JAK3), NIMA Related Kinase 6 (NEK6), and vascular endothelial growth factor receptor 2 kinase (VEGFR2) with activities in the micromolar range for each. The effect of betulin on the cell viability of doxorubicin-resistant K562R chronic myelogenous leukemia cells was then verified to investigate its putative use as an anti-cancer compound. Betulin was shown to modulate the mitogen-activated protein (MAP) kinase pathway, with activity similar to that of imatinib mesylate, a known ABL1 kinase inhibitor. The interaction of betulin and ABL1 was studied by molecular docking, revealing an interaction of the inhibitor with the ABL1 ATP binding pocket. Together, these data demonstrate that betulin is a multi-target inhibitor of protein kinases, an activity that can contribute to the anticancer properties of the natural compound and to potential treatments for leukemia.
Assuntos
Acacia/química , Antineoplásicos Fitogênicos/farmacologia , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-abl/antagonistas & inibidores , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Apoptose/genética , Sítios de Ligação , Caseína Quinase 1 épsilon/antagonistas & inibidores , Caseína Quinase 1 épsilon/genética , Caseína Quinase 1 épsilon/metabolismo , Proliferação de Células/efeitos dos fármacos , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/genética , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Janus Quinase 3/antagonistas & inibidores , Janus Quinase 3/genética , Janus Quinase 3/metabolismo , Células K562 , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Modelos Moleculares , Quinases Relacionadas a NIMA/antagonistas & inibidores , Quinases Relacionadas a NIMA/genética , Quinases Relacionadas a NIMA/metabolismo , Casca de Planta/química , Extratos Vegetais/química , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/isolamento & purificação , Proteínas Proto-Oncogênicas c-abl/química , Proteínas Proto-Oncogênicas c-abl/genética , Proteínas Proto-Oncogênicas c-abl/metabolismo , Transdução de Sinais , Triterpenos/química , Triterpenos/isolamento & purificação , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Applied electric fields (static and pulsing) are widely used in orthopedic practices to treat nonunions and spine fusions and have been shown to improve ligament healing in vivo. Few studies, however, have addressed the effect of electric fields (EFs) on ligament fibroblast migration and biosynthesis. In the current study, we applied static and pulsing direct current (DC) EFs to calf anterior cruciate ligament (ACL) fibroblasts. ACL fibroblasts demonstrated enhanced migration speed and perpendicular alignment to the applied EFs. The motility of ligament fibroblasts was further modulated on type I collagen. In addition, type I collagen expression increased in ACL fibroblasts after exposure to pulsing EFs. In vitro wound-healing studies showed inhibitory effects of static EFs, which were alleviated with a pulsing EF. Our results demonstrate that applied EFs augment ACL fibroblast migration and biosynthesis and provide potential mechanisms by which EFs may be used for enhancing ligament healing and repair.