RESUMO
BACKGROUND AND AIM: Liver fibrosis is a worldwide clinical challenge during the progression of chronic liver disease to liver cirrhosis. Shikonin is extracted from the root of Lithospermum erythrorhizon with antioxidant, anti-inflammatory, anticancer, and wound-healing properties. The study aims to investigate the protective effect of shikonin on liver fibrosis and its underlying mechanism. METHODS: Two liver fibrosis models were established in male C57 mice by intraperitoneal injection of CCl4 or bile duct ligation. Shikonin was administered orally three times weekly at a dose of 2.5 or 5 mg/kg. Protein and mRNA expressions were assayed by quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemical staining. RESULTS: Shikonin significantly inhibited activation of hepatic stellate cells and extracellular matrix formation by downregulating the transforming growth factor-ß1 expression and maintaining the normal balance between metalloproteinase-2 and tissue inhibitor of metalloproteinase-1. Shikonin also decreased hepatic stellate cell energy production by inhibiting autophagy. CONCLUSIONS: The results confirmed that shikonin attenuated liver fibrosis by downregulating the transforming growth factor-ß1/Smads pathway and inhibiting autophagy.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Cirrose Hepática/metabolismo , Cirrose Hepática/prevenção & controle , Naftoquinonas/farmacologia , Proteínas Smad Reguladas por Receptor/antagonistas & inibidores , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Alanina Transaminase/sangue , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Aspartato Aminotransferases/sangue , Autofagia/efeitos dos fármacos , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Matriz Extracelular/metabolismo , Células Estreladas do Fígado/fisiologia , Cirrose Hepática/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Naftoquinonas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Inibidor Tecidual de Metaloproteinase-1/metabolismoRESUMO
Bone Morphogenetic Proteins (BMPs) have multiple activities in the developing spinal cord: they specify the identity of the dorsal-most neuronal populations and then direct the trajectories of dorsal interneuron (dI) 1 commissural axons. How are these activities decoded by dorsal neurons to result in different cellular outcomes? Our previous studies have shown that the diverse functions of the BMPs are mediated by the canonical family of BMP receptors and then regulated by specific inhibitory (I) Smads, which block the activity of a complex of Smad second messengers. However, the extent to which this complex translates the different activities of the BMPs in the spinal cord has remained unresolved. Here, we demonstrate that the receptor-activated (R) Smads, Smad1 and Smad5 play distinct roles mediating the abilities of the BMPs to direct cell fate specification and axon outgrowth. Smad1 and Smad5 occupy spatially distinct compartments within the spinal cord, with Smad5 primarily associated with neural progenitors and Smad1 with differentiated neurons. Consistent with this expression profile, loss of function experiments in mouse embryos reveal that Smad5 is required for the acquisition of dorsal spinal neuron identities whereas Smad1 is critical for the regulation of dI1 axon outgrowth. Thus the R-Smads, like the I-Smads, have discrete roles mediating BMP-dependent cellular processes during spinal interneuron development.
Assuntos
Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Smad Reguladas por Receptor/metabolismo , Medula Espinal/embriologia , Medula Espinal/metabolismo , Animais , Proteínas Aviárias/antagonistas & inibidores , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Axônios/metabolismo , Sequência de Bases , Embrião de Galinha , Regulação da Expressão Gênica no Desenvolvimento , Imuno-Histoquímica , Hibridização In Situ , Interneurônios/citologia , Interneurônios/metabolismo , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Modelos Neurológicos , Neurogênese , RNA Interferente Pequeno/genética , Ratos , Proteínas Smad Reguladas por Receptor/antagonistas & inibidores , Proteínas Smad Reguladas por Receptor/genética , Proteína Smad1/antagonistas & inibidores , Proteína Smad1/genética , Proteína Smad1/metabolismo , Proteína Smad5/antagonistas & inibidores , Proteína Smad5/genética , Proteína Smad5/metabolismo , Medula Espinal/citologiaRESUMO
OBJECTIVE: Salvanic Acid B (Sal B) was proved to show significant effect against fibrosis and myocardial injury. This study aimed to investigate the protective effects and the mechanisms of Sal B on myocardial fibrosis. METHODS: The mice were randomly assigned to five groups: control group, model group, positive group, low-dose group, high-dose group. Hematoxylin-Eosin (HE) staining and Masson staining were used to assess the myocardial physiological changes and measure the myocardial fibrosis area. Expression of transforming growth factor-beta (TGF-ß), drosophila mothers against decapentaplegic (Smad)2, Smad3 and Smad7 were analyzed by immunohistochemistry and real-time PCR. On the other hand, mouse cardiac fibroblasts (CFs) cells were co-treated with 20 ng/mL TGF-ß1 and different concentrations of Sal B (5, 10, and 20 ng/mL) for 24 h. The cells morphology changes were assessed under a microscope, and the protein expressions induced by TGF-ß1 were detected by Western blot. RESULTS: Compared with the model group, myocardial collagen fibers decreased obviously with Sal B treatment (p < 0.05). Moreover, the expression of key signal molecules of the TGF-ß/Smads signaling pathway, including TGF-ß1, Smad2 and Smad3 proteins decreased, while the expression of Smad7 increased in Sal B treatment groups as compared to those of the model group (p < 0.05). On the other hand, results of CFs studies were also consistent with those animals. CONCLUSIONS: Sal B could inhibit the myocardial fibrosis process through regulating TGF-ß/Smads signal transduction pathways.
Assuntos
Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/metabolismo , Extratos Vegetais/uso terapêutico , Salvia miltiorrhiza , Proteínas Smad Reguladas por Receptor/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Relação Dose-Resposta a Droga , Fibrose/tratamento farmacológico , Fibrose/metabolismo , Fibrose/patologia , Masculino , Camundongos , Infarto do Miocárdio/patologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Proteínas Smad Reguladas por Receptor/antagonistas & inibidores , Fator de Crescimento Transformador beta1/antagonistas & inibidoresRESUMO
Smad7 is an inhibitor of the transforming growth factor-beta-activated signaling pathway. Under well-oxygenated conditions, Smad7 is a potent inhibitor of carcinoma cell invasion. Paradoxically, however, the expression of Smad7 is upregulated across several cancers and may promote cancer progression. Hypoxia, which is frequently met in solid tumors, is an enhancer of carcinoma cell invasion and cancer progression. Here, we report that hypoxia activates the expression of Smad7 in a hypoxia-inducible factor- and von Hippel-Lindau protein-dependent manner. As expected, in normoxia, the forced expression of Smad7 inhibited carcinoma cell invasion. In contrast with the normoxic condition, the inhibitory effect of Smad7 was lost under hypoxia. The block in carcinoma cell invasion by forced expression of Smad7 was released by hypoxia in two invasive carcinoma cell lines. Moreover, the noninvasive HaCaT keratinocytes become invasive upon simultaneous hypoxia and transforming growth factor-beta stimulus. The hypoxia-activated invasion was attenuated by inhibiting Smad7 expression by short interfering RNA. Finally, the increased Smad7 expression in human carcinomas correlated with hypoxic gene expression. The data provide evidence that hypoxia could convert Smad7 function from an invasion inhibitor into an activator of invasion. Furthermore, they might shed light as to why increased Smad7 expression is detected in cancers.