RESUMO
Cholesterol sulfate (CS) is an activator of retinoic acid-related orphan receptor α (RORα). CS treatment or RORα overexpression attenuates osteoclastogenesis in a collagen-induced arthritis mouse model. However, the mechanism by which CS and RORα regulate osteoclast differentiation remains largely unknown. Thus, we aimed to investigate the role of CS and RORα in osteoclastogenesis and their underlying mechanism. CS inhibited osteoclast differentiation, but RORα deficiency did not affect osteoclast differentiation and CS-mediated inhibition of osteoclastogenesis. CS enhanced adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and sirtuin1 (Sirt1) activity, leading to nuclear factor-κB (NF-κB) inhibition by decreasing acetylation at Lys310 of p65. The NF-κB inhibition was restored by AMPK inhibitor, but the effects of CS on AMPK and NF-κB were not altered by RORα deficiency. CS also induced osteoclast apoptosis, which may be due to sustained AMPK activation and consequent NF-κB inhibition, and the effects of CS were significantly reversed by interleukin-1ß treatment. Collectively, these results indicate that CS inhibits osteoclast differentiation and survival by suppressing NF-κB via the AMPK-Sirt1 axis in a RORα-independent manner. Furthermore, CS protects against bone destruction in lipopolysaccharide- and ovariectomy-mediated bone loss mouse models, suggesting that CS is a useful therapeutic candidate for treating inflammation-induced bone diseases and postmenopausal osteoporosis.
Assuntos
Reabsorção Óssea , Ésteres do Colesterol , NF-kappa B , Animais , Feminino , Camundongos , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Diferenciação Celular , NF-kappa B/metabolismo , Osteoclastos/metabolismo , Osteogênese , Ligante RANK/farmacologia , Sirtuína 1/genética , Sirtuína 1/metabolismo , Ésteres do Colesterol/farmacologia , Ésteres do Colesterol/uso terapêuticoRESUMO
Nonalcoholic steatohepatitis (NASH) is a liver disease characterized by fat accumulation and chronic inflammation in the liver. Dynein light chain of 8 kDa (LC8) was identified previously as an inhibitor of nuclear factor kappa B (NF-κB), a key regulator of inflammation, however, its role in NASH remains unknown. In this study, we investigated whether LC8 can alleviate NASH using a mouse model of methionine and choline-deficient (MCD) diet-induced NASH and examined the underlying mechanism. LC8 transgenic (Tg) mice showed lower hepatic steatosis and less progression of NASH, including hepatic inflammation and fibrosis, compared to wild-type (WT) mice after consuming an MCD diet. The hepatic expression of lipogenic genes was lower, while that of lipolytic genes was greater in LC8 Tg mice than WT mice, which might be associated with resistance of LC8 Tg mice to hepatic steatosis. Consumption of an MCD diet caused oxidative stress, IκBα phosphorylation, and subsequent p65 liberation from IκBα and nuclear translocation, resulting in induction of proinflammatory cytokines and chemokines. However, these effects of MCD diet were reduced by LC8 overexpression. Collectively, these results suggest that LC8 alleviates MCD diet-induced NASH by inhibiting NF-κB through binding to IκBα to interfere with IκBα phosphorylation and by reducing oxidative stress via scavenging reactive oxygen species. Thus, boosting intracellular LC8 could be a potential therapeutic strategy for patients with NASH.
Assuntos
Dineínas , NF-kappa B , Hepatopatia Gordurosa não Alcoólica , Estresse Oxidativo , Animais , Colina/metabolismo , Dineínas do Citoplasma , Dieta , Modelos Animais de Doenças , Dineínas/genética , Dineínas/metabolismo , Inflamação/metabolismo , Fígado/metabolismo , Fígado/patologia , Metionina/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Inibidor de NF-kappaB alfa/metabolismo , NF-kappa B/metabolismo , Hepatopatia Gordurosa não Alcoólica/genéticaRESUMO
Many bone diseases such as osteoporosis and periodontitis are caused by hyperactivation of osteoclasts. Calcium (Ca2+ ) signals are crucial for osteoclast differentiation and function. Thus, the blockade of Ca2+ signaling may be a strategy for regulating osteoclast activity and has clinical implications. Flunarizine (FN) is a Ca2+ channel antagonist that has been used for reducing migraines. However, the role of FN in osteoclast differentiation and function remains unknown. Here, we investigated whether FN regulates osteoclastogenesis and elucidated the molecular mechanism. FN inhibited osteoclast differentiation along with decreased expression of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), and attenuated osteoclast maturation and bone resorption. FN inhibition of osteoclast differentiation was restored by ectopic expression of constitutively active NFATc1. FN reduced calcium oscillations and its inhibition of osteoclast differentiation and resorption function was reversed by ionomycin, an ionophore that binds Ca2+ . FN also inhibited Ca2+ /calmodulin-dependent protein kinase IV (CaMKIV) and calcineurin leading to a decrease in the cAMP-responsive element-binding protein-dependent cFos and peroxisome proliferator-activated receptor-γ coactivator 1ß expression, and NFATc1 nuclear translocation. These results indicate that FN inhibits osteoclastogenesis via regulating CaMKIV and calcineurin as a Ca2+ channel blocker. In addition, FN-induced apoptosis in osteoclasts and promoted osteogenesis. Furthermore, FN protected lipopolysaccharide- and ovariectomy-induced bone destruction in mouse models, suggesting that it has therapeutic potential for treating inflammatory bone diseases and postmenopausal osteoporosis.
Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Flunarizina/antagonistas & inibidores , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Animais , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/metabolismo , Calcineurina/metabolismo , Diferenciação Celular/efeitos dos fármacos , Flunarizina/metabolismo , Humanos , Fatores de Transcrição NFATC/efeitos dos fármacos , Fatores de Transcrição NFATC/metabolismo , Osteoclastos/metabolismo , Osteogênese/fisiologia , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Ligante RANK/metabolismoRESUMO
Cinchonine (CN) has been known to exert antimalarial, antiplatelet, and antiobesity effects. It was also recently reported to inhibit transforming growth factor ß-activated kinase 1 (TAK1) and protein kinase B (AKT) through binding to tumor necrosis factor receptor-associated factor 6 (TRAF6). However, its role in bone metabolism remains largely unknown. Here, we showed that CN inhibits osteoclast differentiation with decreased expression of nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), a key determinant of osteoclastogenesis. Immunoblot and quantitative real-time polymerase chain reaction analysis as well as the reporter assay revealed that CN inhibits nuclear factor-κB and activator protein-1 by regulating TAK1. CN also attenuated the activation of AKT, cyclic AMP response element-binding protein, and peroxisome proliferator-activated receptor-γ coactivator 1ß (PGC1ß), an essential regulator of mitochondrial biogenesis. Collectively, these results suggested that CN may inhibit TRAF6-mediated TAK1 and AKT activation, which leads to downregulation of NFATc1 and PGC1ß resulting in the suppression of osteoclast differentiation. Interestingly, CN not only inhibited the maturation and resorption function of differentiated osteoclasts but also promoted osteoblast differentiation. Furthermore, CN protected lipopolysaccharide- and ovariectomy-induced bone destruction in mouse models, suggesting its therapeutic potential for treating inflammation-induced bone diseases and postmenopausal osteoporosis.
Assuntos
Diferenciação Celular , Alcaloides de Cinchona/farmacologia , Osteoclastos/citologia , Osteoclastos/metabolismo , Osteogênese , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Reabsorção Óssea/metabolismo , Reabsorção Óssea/patologia , Diferenciação Celular/efeitos dos fármacos , Alcaloides de Cinchona/química , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/patologia , Lipopolissacarídeos , MAP Quinase Quinase Quinases/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/metabolismo , Proteínas Nucleares/metabolismo , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ovariectomia , Ligante RANK/farmacologia , Células RAW 264.7 , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Excessive osteoclast activity can lead to an imbalance between the synthesis and breakdown of bone, with pathologic consequences that include osteoporosis and periodontitis. Thus, controlling osteoclast differentiation and function has significant therapeutic implications. In this study, we investigated the effects of dehydrocostus lactone (DL) on osteoclast differentiation and activation and elucidated the possible mechanisms underlying these processes. DL suppressed osteoclast differentiation by reducing the expression of the nuclear factor of activated T-cells, cytoplasmic 1. When used to challenge differentiated osteoclasts, DL also effectively inhibited their enlargement and resorption activity, and biochemical approaches revealed that DL attenuates osteoclast activation by inhibiting the migration and lysosome biogenesis and secretion via the down-regulation of integrin ß3, PKC-ß, and autophagy related 5 expression. Furthermore, DL prevented bone destruction in inflammation- and ovariectomy-induced osteolytic mouse models. These results indicate that DL has therapeutic potential to treat bone diseases caused by excessive or hyperactive osteoclasts.-Lee, H. I., Lee, J., Hwang, D., Lee, G.-R., Kim, N., Kwon, M., Lee, H., Piao, D., Kim, H. J., Kim, N. Y., Kim, H. S., Seo, E. K., Kang, D., Jeong, W. Dehydrocostus lactone suppresses osteoclast differentiation by regulating NFATc1 and inhibits osteoclast activation through modulating migration and lysosome function.
Assuntos
Lactonas/farmacologia , Fatores de Transcrição NFATC/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Sesquiterpenos/farmacologia , Animais , Reabsorção Óssea/metabolismo , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Osteoclastos/citologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Many bone diseases, such as osteoporosis and rheumatoid arthritis, are attributed to an increase in osteoclast number or activity; therefore, control of osteoclasts has significant clinical implications. This study shows how skullcapflavone II (SFII), a flavonoid with anti-inflammatory activity, regulates osteoclast differentiation, survival, and function. SFII inhibited osteoclastogenesis with decreased activation of MAPKs, Src, and cAMP response element-binding protein (CREB), which have been known to be redox sensitive. SFII decreased reactive oxygen species by scavenging them or activating nuclear factor-erythroid 2-related factor 2 (Nrf2), and its effects were partially reversed by hydrogen peroxide cotreatment or Nrf2 deficiency. In addition, SFII attenuated survival, migration, and bone resorption, with a decrease in the expression of integrin ß3, Src, and p130 Crk-associated substrate, and the activation of RhoA and Rac1 in differentiated osteoclasts. Furthermore, SFII inhibited osteoclast formation and bone loss in an inflammation- or ovariectomy-induced osteolytic mouse model. These findings suggest that SFII inhibits osteoclastogenesis through redox regulation of MAPKs, Src, and CREB and attenuates the survival and resorption function by modulating the integrin pathway in osteoclasts. SFII has therapeutic potential in the treatment and prevention of bone diseases caused by excessive osteoclast activity.-Lee, J., Son, H. S., Lee, H. I., Lee, G.-R., Jo, Y.-J., Hong, S.-E., Kim, N., Kwon, M., Kim, N. Y., Kim, H. J., Lee, Y. J., Seo, E. K., Jeong, W. Skullcapflavone II inhibits osteoclastogenesis by regulating reactive oxygen species and attenuates the survival and resorption function of osteoclasts by modulating integrin signaling.
Assuntos
Flavonoides/toxicidade , Integrinas/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Osteoclastos/metabolismo , Osteólise/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Osteoclastos/patologia , Osteólise/induzido quimicamente , Osteólise/patologiaRESUMO
Excessive and hyperactive osteoclast activity causes bone diseases such as osteoporosis and periodontitis. Thus, the regulation of osteoclast differentiation has clinical implications. We recently reported that dehydrocostus lactone (DL) inhibits osteoclast differentiation by regulating a nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), but the underlying mechanism remains to be elucidated. Here we demonstrated that DL inhibits NFATc1 by regulating nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and nuclear factor-erythroid 2- related factor 2 (Nrf2). DL attenuated IκBα phosphorylation and p65 nuclear translocation as well as decreased the expression of NF-κB target genes and c-Fos. It also inhibited c-Jun N-terminal kinase (JNK) but not p38 or extracellular signalregulated kinase. The reporter assay revealed that DL inhibits NF-κB and AP-1 activation. In addition, DL reduced reactive oxygen species either by scavenging them or by activating Nrf2. The DL inhibition of NFATc1 expression and osteoclast differentiation was less effective in Nrf2-deficient cells. Collectively, these results suggest that DL regulates NFATc1 by inhibiting NF-κB and AP-1 via down-regulation of IκB kinase and JNK as well as by activating Nrf2, and thereby attenuates osteoclast differentiation. [BMB Reports 2020; 53(4): 218-222].
Assuntos
Lactonas/farmacologia , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Sesquiterpenos/farmacologia , Animais , Reabsorção Óssea/metabolismo , Diferenciação Celular/efeitos dos fármacos , Feminino , Quinase I-kappa B/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/metabolismo , Fatores de Transcrição NFATC/fisiologia , Osteoclastos/efeitos dos fármacos , Osteogênese/fisiologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ligante RANK/farmacologia , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição AP-1/metabolismoRESUMO
Bone diseases such as osteoporosis and periodontitis are induced by excessive osteoclastic activity, which is closely associated with inflammation. Benzydamine (BA) has been used as a cytokine-suppressive or non-steroidal anti-inflammatory drug that inhibits the production of pro-inflammatory cytokines or prostaglandins. However, its role in osteoclast differentiation and function remains unknown. Here, we explored the role of BA in regulating osteoclast differentiation and elucidated the underlying mechanism. BA inhibited osteoclast differentiation and strongly suppressed interleukin-1ß (IL-1ß) production. BA inhibited osteoclast formation and bone resorption when added to bone marrow-derived macrophages and differentiated osteoclasts, and the inhibitory effect was reversed by IL-1ß treatment. The reporter assay and the inhibitor study of IL-1ß transcription suggested that BA inhibited nuclear factor-κB and activator protein-1 by regulating IκB kinase, extracellular signal regulated kinase and P38, resulting in the down-regulation of IL-1ß expression. BA also promoted osteoblast differentiation. Furthermore, BA protected lipopolysaccharide- and ovariectomy-induced bone loss in mice, suggesting therapeutic potential against inflammation-induced bone diseases and postmenopausal osteoporosis.
RESUMO
Excessive bone resorption caused by increased osteoclast number or activity leads to a variety of bone diseases including osteoporosis, rheumatoid arthritis and periodontitis. Thus, the therapeutic strategy for these diseases has been focused primarily on the inhibition of osteoclast formation and function. This study shows that euphorbia factor L1 (EFL1), a diterpenoid isolated from Euphorbia lathyris, inhibited osteoclastogenesis and induced osteoclast apoptosis. EFL1 suppressed osteoclast formation and bone resorption at both initial and terminal differentiation stages. EFL1 inhibited receptor activator of NF-κB ligand (RANKL)-induced NFATc1 induction with attenuated NF-κB activation and c-Fos expression. EFL1 decreased the level of reactive oxygen species by scavenging them or activating Nrf2, and inhibited PGC-1ß that regulates mitochondria biogenesis. In addition, EFL1 induced apoptosis in differentiated osteoclasts by increasing Fas ligand expression followed by caspase activation. Moreover, EFL1 inhibited inflammation-induced bone erosion and ovariectomy-induced bone loss in mice. These findings suggest that EFL1 inhibits osteoclast differentiation by regulating cellular redox status and induces Fas-mediated apoptosis in osteoclast, and may provide therapeutic potential for preventing or treating bone-related diseases caused by excessive osteoclast.
Assuntos
Apoptose/efeitos dos fármacos , Diterpenos/farmacologia , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Fenilpropionatos/farmacologia , Ligante RANK/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Animais , Apoptose/genética , Reabsorção Óssea , Caspases/genética , Caspases/metabolismo , Diferenciação Celular , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Feminino , Regulação da Expressão Gênica , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , Osteoclastos/citologia , Osteoclastos/metabolismo , Osteogênese/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ligante RANK/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Receptor fas/genética , Receptor fas/metabolismoRESUMO
Cancer cells have been suggested to be more susceptible to oxidative damages and highly dependent on antioxidant capacity in comparison with normal cells, and thus targeting antioxidant enzymes has been a strategy for effective cancer treatment. Sulfiredoxin (Srx) is an enzyme that catalyzes the reduction of sulfinylated peroxiredoxins and thereby reactivates them. In this study we developed a Srx inhibitor, K27 (N-[7-chloro-2-(4-fluorophenyl)-4-quinazolinyl]-N-(2-phenylethyl)-ß-alanine), and showed that it induces the accumulation of sulfinylated peroxiredoxins and oxidative stress, which leads to mitochondrial damage and apoptotic death of cancer cells. The effects of K27 were significantly reversed by ectopic expression of Srx or antioxidant N-acetyl cysteine. In addition, K27 led to preferential death of tumorigenic cells over non-tumorigenic cells, and suppressed the growth of xenograft tumor without acute toxicity. Our results suggest that targeting Srx might be an effective therapeutic strategy for cancer treatment through redox-mediated cell death.
Assuntos
Adenocarcinoma Bronquioloalveolar/tratamento farmacológico , Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/antagonistas & inibidores , Quinazolinas/farmacologia , Espécies Reativas de Oxigênio/agonistas , beta-Alanina/análogos & derivados , Células A549 , Acetilcisteína/farmacologia , Adenocarcinoma Bronquioloalveolar/metabolismo , Adenocarcinoma Bronquioloalveolar/patologia , Animais , Antineoplásicos/síntese química , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células , Inibidores Enzimáticos/síntese química , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Expressão Gênica , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Terapia de Alvo Molecular , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/genética , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Quinazolinas/síntese química , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , beta-Alanina/síntese química , beta-Alanina/farmacologiaRESUMO
Recent studies have shown that many types of cancer cells have increased levels of reactive oxygen species (ROS) and enhance antioxidant capacity as an adaptation to intrinsic oxidative stress, suggesting that cancer cells are more vulnerable to oxidative insults and are more dependent on antioxidant systems compared with normal cells. Thus, disruption of redox homeostasis caused by a decline in antioxidant capacity may provide a method for the selective death of cancer cells. Here we show that ROS-mediated selective death of tumor cells can be caused by inhibiting sulfiredoxin (Srx), which reduces hyperoxidized peroxiredoxins, leading to their reactivation. Srx inhibitor increased the accumulation of sulfinic peroxiredoxins and ROS, which led to oxidative mitochondrial damage and caspase activation, resulting in the death of A549 human lung adenocarcinoma cells. Srx depletion also inhibited the growth of A549 cells like Srx inhibition, and the cytotoxic effects of Srx inhibitor were considerably reversed by Srx overexpression or antioxidants such as N-acetyl cysteine and butylated hydroxyanisol. Moreover, Srx inhibitor rendered tumorigenic ovarian cells more susceptible to ROS-mediated death compared with nontumorigenic cells and significantly suppressed the growth of A549 xenografts without acute toxicity. Our results suggest that Srx might serve as a novel therapeutic target for cancer treatment based on ROS-mediated cell death.
Assuntos
Antineoplásicos/farmacologia , Benzoatos/farmacologia , Mitocôndrias/efeitos dos fármacos , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Cholangiocarcinoma is one of the most difficult malignancies to cure. An important prognostic factor is metastasis, which precludes curative surgical resection. Recent evidence shows that capsaicin has an inhibitory effect on cancer cell migration and invasion. Here, we investigated the molecular mechanism of the capsaicin-induced anti-migration and anti-invasion effects on HuCCT1 cholangiocarcinoma cells. Migration and invasion were significantly reduced in response to capsaicin. Capsaicin also inhibited the expression of matrix metalloproteinase-9 (MMP-9). In capsaicin-treated cells, levels of phosphorylated AMPK increased, and this effect was abolished by treatment with the AMPK inhibitor, Compound C. Capsaicin enhanced the expression of SIRT1, which can activate the transcription factor NF-κB by deacetylation. This suggests that NF-κB is activated by capsaicin via the SIRT1 pathway. In addition, capsaicin-activated AMPK induced the phosphorylation of IκBα and nuclear localization of NF-κB p65. Chromatin immunoprecipitation assays demonstrated that capsaicin reduced MMP-9 transcription by inhibiting NF-κB p65 translocation and deacetylation via SIRT1. These findings provide evidence that capsaicin suppresses the migration and invasion of cholangiocarcinoma cells by inhibiting NF-κB p65 via the AMPK-SIRT1 and the AMPK-IκBα signaling pathways, leading to subsequent suppression of MMP-9 expression.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/patologia , Capsaicina/farmacologia , Movimento Celular/efeitos dos fármacos , Colangiocarcinoma/patologia , Metaloproteinase 9 da Matriz/metabolismo , NF-kappa B/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Acetilação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/metabolismo , Ductos Biliares Intra-Hepáticos/efeitos dos fármacos , Ductos Biliares Intra-Hepáticos/metabolismo , Western Blotting , Proliferação de Células/efeitos dos fármacos , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/metabolismo , Imunoprecipitação da Cromatina , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imunoprecipitação , Metaloproteinase 9 da Matriz/genética , NF-kappa B/genética , Invasividade Neoplásica , Fosforilação/efeitos dos fármacos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fármacos do Sistema Sensorial/farmacologia , Células Tumorais Cultivadas , Cicatrização/efeitos dos fármacosRESUMO
Aurora A kinase has drawn considerable attention as a therapeutic target for cancer therapy. However, the underlying molecular and cellular mechanisms of the anticancer effects of Aurora A kinase inhibition are still not fully understood. Herein, we show that depletion of Aurora A kinase by RNA interference (RNAi) in hepatocellular carcinoma (HCC) cells upregulated FoxO1 in a p53-dependent manner, which induces cell cycle arrest. Introduction of an RNAi-resistant Aurora A kinase into Aurora A-knockdown cells resulted in downregulation of FoxO1 expression and rescued proliferation. In addition, silencing of FoxO1 in Aurora A-knockdown cells allowed the cells to exit cytostatic arrest, which, in turn, led to massive cell death. Our results suggest that FoxO1 is responsible for growth arrest at the G2/M phase that is induced by Aurora A kinase inhibition.
Assuntos
Fatores de Transcrição Forkhead/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Apoptose , Aurora Quinases , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Regulação para Baixo , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/antagonistas & inibidores , Fatores de Transcrição Forkhead/genética , Pontos de Checagem da Fase G2 do Ciclo Celular , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Pontos de Checagem da Fase M do Ciclo Celular , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
OBJECTIVE: Visceral obesity contributes to the development of obesity-related disorders such as diabetes, hyperlipidemia, and fatty liver disease, as well as cardiovascular diseases. In this study, we determined whether topical application of capsaicin can reduce fat accumulation in visceral adipose tissues. METHODS AND RESULTS: We first observed that topical application of 0.075% capsaicin to male mice fed a high-fat diet significantly reduced weight gain and visceral fat. Fat cells were markedly smaller in the mesenteric and epididymal adipose tissues of mice treated with capsaicin cream. The capsaicin treatment also lowered serum levels of fasting glucose, total cholesterol, and triglycerides. Immunoblot analysis and RT-PCR revealed increased expression of adiponectin and other adipokines including peroxisome proliferator-activated receptor (PPAR) α, PPARγ, visfatin, and adipsin, but reduced expression of tumor necrosis factor-α and IL-6. CONCLUSIONS: These results indicate that topical application of capsaicin to obese mice limits fat accumulation in adipose tissues and may reduce inflammation and increase insulin sensitivity.
Assuntos
Adipocinas/metabolismo , Capsaicina/uso terapêutico , Dieta Hiperlipídica/efeitos adversos , Gordura Intra-Abdominal/efeitos dos fármacos , Obesidade/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Adipócitos/efeitos dos fármacos , Adiponectina/metabolismo , Administração Tópica , Animais , Glicemia/metabolismo , Capsaicina/administração & dosagem , Capsaicina/farmacologia , Capsicum/química , Colesterol/sangue , Fator D do Complemento/metabolismo , Epididimo , Interleucina-6/metabolismo , Gordura Intra-Abdominal/citologia , Gordura Intra-Abdominal/metabolismo , Masculino , Mesentério , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Nicotinamida Fosforribosiltransferase/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , PPAR alfa/metabolismo , PPAR gama/metabolismo , Extratos Vegetais/farmacologia , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/metabolismo , Aumento de Peso/efeitos dos fármacosRESUMO
Embryonic stem cells (ESCs) can be propagated in vitro on feeder layers of mouse STO fibroblast cells. The STO cells secrete several cytokines that are essential for ESCs to maintain their undifferentiated state. In this study, we found significant growth inhibition of mouse ESCs (mESCs) cultured on STO cells infected with adenovirus containing a dominant-negative mutant form of IκB (rAd-dnIκB). This blockage of the NF-κB signal pathway in STO cells led to a significant decrease in [(3)H]thymidine incorporation and colony formation of mESCs. Expression profile of cytokines secreted from the STO cells revealed an increase in the bone morphogenetic protein4 (BMP4) transcript level in the STO cells infected with adenoviral vector encoding dominant negative IκB (rAd-dnIκB). These results suggested that the NF-κB signaling pathway represses expression of BMP4 in STO feeder cells. Conditioned medium from the rAd-dnIκB-infected STO cells also significantly reduced the colony size of mESCs. Addition of BMP4 prevented colony formation of mESCs cultured in the conditioned medium. Our finding suggested that an excess of BMP4 in the conditioned medium also inhibits proliferation of mESCs.