RESUMO
Acid-sensing ion channels (ASICs), a group of Na(+)-selective and Ca(2+)-permeant ligand-gated cation channels, can be transiently activated by extracellular acid. Among seven subunits of ASICs, acid-sensing ion channel 1a (ASIC1a), which is responsible for Ca(2+) transportation, is elevated in response to inflammation, tumor, and ischemic injury in central nervous system and non-neuronal tissues. In this study, we demonstrated for the first time the presence of ASIC1a in rat liver and hepatic stellate cells (HSCs). Furthermore, the expression of ASIC1a was increased in primary HSCs and liver tissues of CCl4-treated rats, suggesting that ASIC1a may play certain role in liver fibrosis. Interestingly, we identified that the level of ASIC1a was significantly elevated in response to platelet-derived growth factor (PDGF) induction in a time- and dose-dependent manner. It was also established that Ca(2+)-transporting ASIC1a was involved in acid-induced injury of different cell types. Moreover, inhibition or silencing of ASIC1a was able to inhibit PDGF-induced pro-fibrogenic effects of activated rat HSCs, including cell activation, de novo synthesis of extracellular matrix components through mitogen-activated protein kinase signaling pathway. Collectively, our studies identified that ASIC1a was expressed in rat liver and HSCs and provided a strong evidence for the involvement of the ASIC1a in the progression of hepatic fibrosis.
Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Intoxicação por Tetracloreto de Carbono/patologia , Células Estreladas do Fígado/citologia , Cirrose Hepática/induzido quimicamente , Fígado/patologia , Sistema de Sinalização das MAP Quinases , Canais Iônicos Sensíveis a Ácido/genética , Animais , Cálcio/metabolismo , Intoxicação por Tetracloreto de Carbono/genética , Intoxicação por Tetracloreto de Carbono/metabolismo , Células Cultivadas , Regulação da Expressão Gênica , Células Estreladas do Fígado/patologia , Fígado/metabolismo , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Masculino , Fator de Crescimento Derivado de Plaquetas , Ratos , Ratos Sprague-DawleyRESUMO
INTRODUCTION: Interleukin (IL)-22, originally referred to as IL-TIF for IL-10-related T cell-derived inducible factor, is a member of the IL-10-like cytokine family. IL-22 is highly expressed by Th17 cells and is tightly linked to chronic inflammation, including inflammatory bowel disease and local intestinal inflammation among others. MATERIALS AND METHODS: A PubMed and Web of Science databases search was performed for studies providing evidences on the role of IL-22 in liver diseases. CONCLUSION: IL-22 plays an important role in ameliorating liver injury in many rodent models by targeting hepatocytes that express high levels of IL-22 receptor 1 and IL-10 receptor 2. This review concisely summarizes the role of IL-22 in the development progression of liver disease of different etiologies. It is focused mainly on the IL-22 intracellular signaling and its influence on liver diseases.
Assuntos
Interleucinas/metabolismo , Hepatopatias/metabolismo , Animais , Humanos , Interleucinas/uso terapêutico , Hepatopatias/tratamento farmacológico , Receptores de Interleucina/metabolismo , Interleucina 22RESUMO
Hepatic fibrosis is a chronic inflammation-associated disease, which is involved in the infiltration of inflammatory cells and releasing of proinflammatory cytokines. In the pathological process, protons are released by damaged cells and acidosis is considered to play a critical role in cell injury. Although the underlying mechanism (s) remain ill-defined, ASICs (acid-sensing ion channels) are assumed to be involved in this process. The diuretic, amiloride, is neuroprotective in models of cerebral ischemia, a property attributable to the inhibition of central ASICs by the drug. However, the effect of inhibition of ASICs by amiloride in the liver fibrotic process remains unclear. We found that amiloride (25, 50, or 100 µM) could restrain acid-induced HSCs at pH6 in vitro. In vivo experiments showed that amiloride could significantly alleviate liver injury, decreasing levels of profibrogenic cytokines, collagen deposition, and reducing pathological tissue damage. In summary, amiloride inhibits hepatic fibrosis in vivo and in vitro, which is probably associated with the downregulation of ASICs.
Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Células Estreladas do Fígado/metabolismo , Bloqueadores do Canal Iônico Sensível a Ácido/farmacologia , Bloqueadores do Canal Iônico Sensível a Ácido/uso terapêutico , Canais Iônicos Sensíveis a Ácido/química , Actinas/metabolismo , Alanina Transaminase/sangue , Amilorida/farmacologia , Amilorida/uso terapêutico , Animais , Aspartato Aminotransferases/sangue , Tetracloreto de Carbono/toxicidade , Células Cultivadas , Colágeno/metabolismo , Citocinas/metabolismo , Canais Epiteliais de Sódio/metabolismo , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/efeitos dos fármacos , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND: The activation of hepatic stellate cells (HSCs) is the key step in the pathogenesis of liver fibrosis, which directly leads to fibrotic pathological changes in the hepatic tissue. Mitochondrial stress exacerbates inflammatory diseases by inducing pathogenic shifts in normal cells. However, the role of mitochondrial stress in HSC activation remains to be elucidated. METHODS: We analyzed the effect of mitochondrial stress on HSC activation. An in vivo hepatic fibrosis model was established by intraperitoneal injection of 40% carbon tetrachloride (CCl4) for 12 weeks. Additionally, using in vitro approach, HSC-T6 cells were treated with 10 ng/mL platelet-derived growth factor-BB (PDGF-BB) for 24 h. RESULTS: Transcriptional activator 4 (ATF4) is highly expressed in fibrotic liver tissue samples and activated HSCs. We found that AAV8-shRNA-Atf4 alleviated liver fibrosis in rats. ATF4 promoted the activation of HSCs, which was induced by mitochondrial stress. The mechanisms involved ATF4 binding to a specific region of the tribble homologue 3 (TRIB3) promoter. Further, TRIB3 promoted HSCs activation mediated by mitochondrial stress. CONCLUSIONS: ATF4 induces mitochondrial stress by upregulating TRIB3, leading to the activation of HSCs. Therefore, the inhibition of ATF4 during mitochondrial stress may be a promising therapeutic target for liver fibrosis.
Assuntos
Células Estreladas do Fígado , Fígado , Ratos , Animais , Células Estreladas do Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/patologia , Becaplermina/efeitos adversos , Becaplermina/metabolismo , FibroseRESUMO
Cytokine-mediated immunity plays a crucial role in the pathogenesis of various autoimmune diseases, including rheumatoid arthritis (RA). Increasing evidence has revealed the importance of IL-23, which closely resembles IL-12 structurally and immunologically, in linking innate and adaptive immunity. IL-23, a newly identified heterodimeric pro-inflammatory cytokine, is composed of a p40 subunit in common with IL-12 and a unique p19 subunit. Recent evidence suggests that IL-23, rather than IL-12, is the crucial factor in the pathogenesis of various immune-mediated disorders. In addition, recent studies have explored the role of IL-23 in patients with RA. An elevated expression of IL-23 has been demonstrated in the synovial fibroblasts and plasma of patients with RA. Moreover, an association between IL-23 and IL-23R polymorphisms with susceptibility to RA has been reported. Therefore, the targeting of IL-23 or the IL-23 receptor has been proposed as a potential therapeutic approach for RA. In this review we will discuss the biological features of IL-23, and summarize recent advances in our understanding of the role of IL-23 in the pathogenesis and treatment of RA.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Interleucina-23/fisiologia , Animais , Artrite Reumatoide/imunologia , Artrite Reumatoide/metabolismo , Humanos , Interleucina-23/metabolismo , Terapia de Alvo Molecular , Receptores de Interleucina/metabolismoRESUMO
OBJECTIVE: The aim of this study was to examine the effect of recombinant human endostatin (rhEndostatin) on adjuvant arthritis (AA) in rats and its possible mechanisms. METHODS: RhEndostatin was subcutaneously administrated to AA rats after immunization. The progression of AA was assessed by the macroscopic arthritis scoring system of paws. Histological examination of the synovial tissues was examined by hematoxylin and eosin staining. The expression level of vascular endothelial growth factor (VEGF) mRNA and proteins in the synovial tissues was evaluated by realtime PCR and immunohistochemistry, respectively. Fibroblast-like synoviocytes (FLS) were isolated from synovial tissues. Cell proliferation assay was evaluateded with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The levels of tumour necrosis factor-alpha (TNF-α) and interleukin-1ß (IL-1ß) in culture medium was examined by radioimmno assay. RESULTS: RhEndostatin attenuated the severity of arthritis on both second hind paw volume and polyarthritis score, as well as improved the arthritic status histologically in AA rats. Simultaneously, rhEndostatin can inhibit the expression of VEGF in synovial tissues. The proliferation of FLS and TNF-α, IL-1ß production from culture medium was significantly inhibited by rhEndostatin. CONCLUSION: Our data suggest that rhEndostatin inhibits adjuvant arthritis by down-regulating VEGF expression and suppression of TNF-α, IL-1ß production.
Assuntos
Artrite Experimental/tratamento farmacológico , Endostatinas/uso terapêutico , Interleucina-1beta/metabolismo , Proteínas Recombinantes/uso terapêutico , Fator de Necrose Tumoral alfa/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Artrite Experimental/metabolismo , Artrite Experimental/patologia , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Proliferação de Células , Células Cultivadas , Regulação para Baixo , Humanos , Cápsula Articular/efeitos dos fármacos , Cápsula Articular/metabolismo , Cápsula Articular/patologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: Acid-sensing ion channels (ASICs) are members of the degenerin/epithelial sodium channel (DEG/ENaC) protein superfamily and play a critical role in acid-induced cell injury. In this study, we examined whether drugs such as amiloride that block ASICs could attenuate acid-induced apoptotic injury to articular chondrocytes. METHODS: Articular chondrocytes were isolated from Sprague-Dawley rats, and their phenotype was determined by toluidine blue and immunocytochemical staining. Articular chondrocyte viability assay was performed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Apoptosis of chondrocytes was observed by the terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling method as well as propidium iodide labeling methods. Intracellular calcium ([Ca(2+)](i)) was analyzed by a Ca(2+)-imaging method. In addition, the expression levels of calpain and calcineurin in articular chondrocytes were examined by real-time PCR and immunocytochemical staining. The activity of caspase-3 was evaluated by spectrophotometric assays. RESULTS: Positive staining for glycosaminoglycan and collagen II was seen in articular chondrocytes. Blocking acid-sensing ion channels significantly decreased the cell death percentage and increased cell viability following acid exposure. After pretreated with amiloride, acid-induced [Ca(2+)](i) rises were reduced. Amiloride also inhibited calpain and calcineurin expression levels in acid-induced chondrocytes, and inhibited caspase-3 activity. CONCLUSION: The data presented in this study provided some experimental evidence that blocking ASICs could protect acid-induced apoptotic injury to chondrocytes.
Assuntos
Condrócitos/metabolismo , Proteínas do Tecido Nervoso/antagonistas & inibidores , Canais Iônicos Sensíveis a Ácido , Amilorida/farmacologia , Animais , Apoptose/efeitos dos fármacos , Calcineurina/metabolismo , Cálcio/metabolismo , Calpaína/metabolismo , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Condrócitos/efeitos dos fármacos , Ácido Clorídrico , Masculino , Ratos , Ratos Sprague-Dawley , Bloqueadores dos Canais de Sódio/farmacologia , Canais de SódioRESUMO
A significant decrease in tissue pH or acidosis is a common feature of numerous diseases, including RA (rheumatoid arthritis). Cartilage homoeostasis is profoundly affected by local acidosis in the joints. The diuretic, amiloride, is neuroprotective in models of cerebral ischaemia, a property attributable to the inhibition of ASICs (acid-sensing ion channels) by the drug. However, little is known about the effect of amiloride on apoptosis induced by extracellular acid in articular chondrocytes. We have found that amiloride could restrain the acid-induced apoptosis of rat articular chondrocytes in vitro. Primary rat articular chondrocytes were isolated, cultured and induced to apoptose by exposure to extracellular solution (pH 6.0), while simultaneously treated with 50-200 µM amiloride. Apoptotic rate, mitochondrial function, levels of apoptosis-related gene Bcl-2 family mRNA and activity of caspase 3/9 in chondrocytes were examined. Amiloride inhibited chondrocyte apoptosis in a dose-dependent manner. Furthermore, amiloride partly restored the levels of mitochondrial membrane potential by regulation of Bcl-2 family gene mRNA expression, and activity of caspase 3/9 in chondrocytes induced by extracellular acid. Our results indicated that amiloride protected against acid-induced apoptosis in rat articular chondrocytes by increasing anti-apoptotic ability and down-regulation of pro-apoptotic factors, thus protecting mitochondrial function.
Assuntos
Amilorida/farmacologia , Apoptose/efeitos dos fármacos , Condrócitos/metabolismo , Diuréticos/farmacologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Canais Iônicos Sensíveis a Ácido , Animais , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Células Cultivadas , Condrócitos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Canais de Sódio/metabolismoRESUMO
Activation of hepatic stellate cells (HSCs) is a key cause of liver fibrosis. However, the mechanisms leading to the activation of HSCs are not fully understood. In the pathological process, acid-sensing ion channel 1a (ASIC1a) is widely involved in the development of inflammatory diseases, suggesting that ASIC1a may play an important role in liver fibrosis. We found that in an acidic environment, ASIC1a leads to HSC-T6 cell activation. Meanwhile, exosomes produced by activated HSC-T6 cells (HSC-EXOs) can be reabsorbed by quiescent HSC-T6 cells to promote their activation. Exosomes mainly carry miRNAs involved in intercellular information exchange. We performed exosome miRNA whole transcriptome sequencing. The results indicated that the acidic environment could alter the miRNA expression profile in the exosomes of HSC-T6 cells. Further studies revealed that ASIC1a promotes the activation of HSCs by regulating miR-301a-3p targeting B-cell translocation gene 1 (BTG1). In conclusion, our study found that ASIC1a may affect HSC activation through the exosomal miR-301a-3p/BTG1 axis, and inhibiting ASIC1a may be a promising treatment strategy for liver fibrosis.
Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Células Estreladas do Fígado/metabolismo , MicroRNAs , Canais Iônicos Sensíveis a Ácido/genética , Animais , Linhagem Celular , Exossomos/genética , Exossomos/metabolismo , Humanos , Cirrose Hepática/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , RatosRESUMO
The activation of hepatic stellate cells (HSCs) is closely related to hepatic fibrosis and plays a key role in its occurrence and development. In the damaged liver, inhibition of the activation, proliferation, and clearance of HSCs is an important therapeutic strategy. However, the mechanism underlying the activation of HSCs is not completely clear. Acid-sensitive ion channel 1a (ASIC1a) is a cation channel activated by extracellular acid, which is responsible for the transport of Ca2+ and Na+ and participates in the activation of HSCs and the occurrence and development of many inflammatory diseases, suggesting that ASIC1a plays an important role in liver fibrosis. A previous study by the project team found that when the membrane channel protein ASIC1a was opened, intracellular Ca2+ levels increased, the expression of CaM/CaMKII in HSCs was high, and HSC was activated and proliferated. Therefore, we established an SD rat model of hepatic fibrosis and induced HSC-T6 activation by stimulating ASIC1a with acid in vitro. In vivo, CCl4 was used to induce liver fibrosis in rats, and different doses of KN93 (0.5, 1, and 2 mg/kg/d) and colchicine (0.1 mg/kg/d) were administered. Eight weeks later, the activities of ALT and AST in serum were measured and hematoxylin-eosin and Masson staining in liver tissue, and immunohistochemistry analysis were performed in SD rats. The expressions of ASIC1a, α-SMA, Collagen-1, CaM, and CaMKII were detected. In vitro, we activated HSC-T6 cells by stimulating ASIC1a with acid. The results showed that inhibition of ASIC1a could improve acid-induced HSCs activation. In addition, CaM/CaMKII was expressed in HSC of rats with hepatic fibrosis regulated by ASIC1a. After blocking or silencing the expression of CaMKII, the fibrosis marker protein can be down-regulated. KN93 also reduced inflammation and improved the activation, proliferation and fibrosis of HSC. In summary, we concluded that CaM/CaMKII participates in ASIC1a regulation of the proliferation and activation of HSC and promotes the occurrence of liver fibrosis.
RESUMO
Acid-sensing ion channels (ASICs) are cationic channels that are activated by extracellular acidification and implicated in pain perception, ischemic stroke, mechanosensation, learning, and memory. It has been shown that ASIC1a is an extracellular pH sensor in the central and peripheral nervous systems, but its physiological and pathological roles in non-neural cells are poorly understood. We demonstrated a novel physiological function of ASIC1a in rat articular chondrocytes. The expression of ASIC1a mRNA and protein in rat articular chondrocytes was evaluated by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting. The distribution of ASIC1a protein located in articular chondrocytes was determined by using immunofluorescence cell staining. The possible molecular mechanisms of articular chondrocytes pH sensing, as assessed by recording intracellular calcium ([Ca(2+)]i) in chondrocytes, were analyzed by using the laser scanning confocal microscopy technique. The cell injury following acid exposure was analyzed with lactate dehydrogenase release assay and electron microscopy. mRNA and protein expression showed that ASIC1a was expressed abundantly in these cells. In cultured chondrocytes, extracellular pH 6.0 increased intracellular calcium in the presence of extracellular Ca(2+). The ASIC1a-specific blocker PcTX venom significantly reduced this increase in [Ca(2+)]i, and inhibited acid-induced articular chondrocyte injury. However, the increase in [Ca(2+)]i and articular chondrocyte injury were not observed in the absence of extracellular Ca(2+). These findings show that increased [Ca(2+)]i, mediated via ASIC1a, might contribute to acidosis-induced articular chondrocyte injury.
Assuntos
Cálcio/metabolismo , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Canais de Sódio/metabolismo , Canais Iônicos Sensíveis a Ácido , Animais , Western Blotting , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/ultraestrutura , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/ultraestrutura , Imunofluorescência , Concentração de Íons de Hidrogênio , L-Lactato Desidrogenase/metabolismo , Masculino , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Peptídeos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/genética , Venenos de Aranha/farmacologia , Fatores de TempoRESUMO
OBJECTIVE: The aim of this study was to examine whether drugs such as amiloride that block acid sensing ion channels (ASICs) could attenuate articular cartilage destruction in adjuvant-induced arthritis (AA). METHODS: Articular chondrocytes were isolated from the normal rats, and intracellular calcium ([Ca(2+)]i) was analyzed with laser scanning confocal microscopy. The cell injury was analyzed with lactate dehydrogenase release assay and electron microscopy. Amiloride or phosphate buffered saline was administered daily to AA rats for 1 week from the time of arthritis onset. Morphology of the articular cartilage was examined by hematoxylin and eosin staining, and Mankin score was calculated. The expression level of type II collagen (COII) and aggrecan mRNA and proteins in the articular cartilage was evaluated by real-time PCR and Western blotting, respectively. RESULTS: The rapid decrease in extracellular pH (6.0) induced a conspicuous increase in [Ca(2+)]i in the articular chondrocytes. Amiloride reduced this increase in [Ca(2+)]i, and inhibited acid-induced articular chondrocyte injury. Amiloride significantly decreased Mankin scores in the articular cartilage in AA rats. COII and aggrecan mRNA and protein expression in the articular cartilage was significantly increased by amiloride. CONCLUSION: These findings represent some experimental evidence of a potential role for ASICs in the pathogenesis of articular cartilage destruction in rheumatoid arthritis.
Assuntos
Amilorida/farmacologia , Artrite Experimental/patologia , Cartilagem Articular/citologia , Condrócitos/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Bloqueadores dos Canais de Sódio/farmacologia , Canais de Sódio/metabolismo , Canais Iônicos Sensíveis a Ácido , Agrecanas/metabolismo , Animais , Artrite Experimental/metabolismo , Células Cultivadas , Condrócitos/citologia , Condrócitos/metabolismo , Colágeno Tipo II/metabolismo , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Sprague-DawleyAssuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Fibroblastos/imunologia , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Interleucinas/metabolismo , Líquido Sinovial/imunologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Feminino , Humanos , MasculinoRESUMO
Reactive oxygen species derived from NADPH oxidase contribute to a wide variety of renal diseases. Nox4, the major NADPH isoform in kidney, produces mainly H2O2 that regulates physiological functions. Nox4 contributes to redox processes involved in diabetic nephropathy, acute kidney injury, obstructive nephropathy, hypertensive nephropathy, renal cell carcinoma and other renal diseases by activating multiple signaling pathways. Although Nox4 is found in a variety of cell types, including epithelial cells, podocytes, mesangial cells, endothelial cells and fibroblasts, its role is not clear and even controversial. In some conditions, Nox4 protects cells by promoting cell survival in response to harmful stimuli. In other scenarios it induces cell apoptosis, inflammation or fibrogenesis. This functional variability may be attributed to distinct cell types, subcellular localization, molecular concentrations, disease type or stage, and other factors yet unexplored. In this setting, we reviewed the function and mechanism of Nox4 in renal diseases, highlighted the contradictions in Nox4 literature, and discussed promising therapeutic strategies targeting Nox4 in the treatment of certain types of renal diseases.
Assuntos
Nefropatias/enzimologia , NADPH Oxidase 4/metabolismo , Animais , Humanos , Oxirredução , Espécies Reativas de Oxigênio/metabolismoRESUMO
Bidens bipinnata L. is well known in China as a traditional Chinese medicine. This study was designed to evaluate the hepatoprotective activity of the total flavonoids of B. bipinnata L. (TFB) against carbon tetrachloride (CCl4)-induced acute liver injury in mice and to determine its mechanism of action. Oral administration of TFB at doses of 50, 100 and 200 mg kg(-1) for 7 days significantly reduced the elevated relative values of liver weight, serum transaminases (alanine aminotransferase and aspartate aminotransferase) and the hepatic morphologic changes induced by CCl4 in mice. In addition, TFB markedly inhibited CCl4-induced lipid peroxidation and enhanced the activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase. Moreover, pretreatment with TFB suppressed nitric oxide production and nuclear factor-kappaB activation in CCl4-treated mice. The results suggest that TFB has significant hepatoprotective activity and its mechanism is related, at least in part, to its antioxidant properties. Further research is required to investigate the detailed mechanism of the protective effect of TFB on acute liver injury.
Assuntos
Bidens/química , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Flavonoides/uso terapêutico , Fígado/efeitos dos fármacos , Substâncias Protetoras/uso terapêutico , Doença Aguda , Animais , Antioxidantes/metabolismo , Intoxicação por Tetracloreto de Carbono/tratamento farmacológico , Intoxicação por Tetracloreto de Carbono/patologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Sequestradores de Radicais Livres/uso terapêutico , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , NF-kappa B/biossíntese , Óxido Nítrico/biossíntese , Tamanho do Órgão , Fitoterapia , Substâncias Protetoras/isolamento & purificação , Substâncias Protetoras/farmacologia , Superóxido Dismutase/metabolismoRESUMO
OBJECTIVE: To screen macroporous resins for isolation and purification of total flavonoids of Bidens bipinnata L. (TFB) through investigating the property of adsorption and desorption of 7 kinds of macroporous adsorption resins for TFB. METHODS: The content of total flavonoids was used as the evaluating criteria, and the static and dynamic adsorption-desorption methods were adopted to compare the adsorption quantity, the rate of desorption and adsorption kinetics of different macroporous adsorption resins. RESULTS: Among 7 kinds of macroporous adsorption resins, the HPD 100 resin was the best for isolating and purifying TFB. CONCLUSION: HPD 100 possess a better adsorbability and separating property, and its property is obviously higher than any other resins.
Assuntos
Bidens/química , Flavonoides/isolamento & purificação , Adsorção , Medicamentos de Ervas Chinesas , Cinética , PorosidadeRESUMO
BACKGROUND: Acid-sensing ion channel 1a (ASIC1a), the primary acid sensors in the nervous system, has been studied earlier in various physiopathologic conditions. However, little is known about the role of ASIC1a in endplate chondrocytes in intervertebral discs (IVDs). METHODS: The expression of ASICs was examined in rat endplate chondrocytes. Effects of treatment with ASIC1a small interfering RNA (siRNA) or selective blocker (PcTX1) on acid-induced intracellular Ca(2+) concentration ([Ca(2+)]i) and cell apoptosis were investigated. ASIC1a involved in Ca(2+)-mediated apoptotic signals in acid-induced endplate chondrocyte apoptosis was also assessed. RESULTS: We showed that ASIC1a is expressed in rat endplate chondrocytes, and blockade of ASIC1a using ASIC1a-siRNA or PcTX1 inhibited acid-induced cell apoptosis and elevation of [Ca(2+)]i. We also demonstrated that the acid-induced [Ca(2+)]i increase via ASIC1a is involved in endplate chondrocyte apoptosis. Moreover, blocking of ASIC1a-mediated [Ca(2+)]i elevation inhibited activation of acid-induced calcium-dependent proteases and decreased BAD phosphorylation in endplate chondrocytes. Similarly, extracellular acidosis induced cytochrome C translocation from the mitochondria to the cytoplasm and activation of caspase-9 and caspase-3, which was inhibited by ASIC1a-siRNA or PcTX1. CONCLUSION: ASIC1a activation in endplate chondrocytes may trigger Ca(2+)-dependent proteases activity and signaling, which leads to apoptosis of endplate chondrocytes in IVDs.
Assuntos
Canais Iônicos Sensíveis a Ácido/fisiologia , Apoptose/fisiologia , Cálcio/metabolismo , Condrócitos/citologia , Lâmina de Crescimento/citologia , Disco Intervertebral/citologia , Canais Iônicos Sensíveis a Ácido/genética , Animais , Calcineurina/metabolismo , Células Cultivadas , Condrócitos/metabolismo , Lâmina de Crescimento/metabolismo , Disco Intervertebral/metabolismo , Transporte de Íons , Microscopia de Fluorescência , Fosforilação , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Retinoic acid (RA) analogs have been used in the treatment of a variety of cancers; however, their application is limited due to serious therapy-related sequelae. In the present study, the effects of a novel RA analog, 4-amino-2-trifluoromethyl-phenyl retinate (ATPR), on the growth of gastric cancer cells were evaluated. Three gastric cancer cell lines, AGS, MKN-74 and SC-M1, were treated with either alltrans retinoic acid (ATRA) or ATPR, and their growth and distribution in different cell cycle phases were assessed using an MTT assay and propidium iodide (PI) staining followed by flow cytometry. The binding affinity of ATPR to the retinoic acid receptors, retinoic acid receptor-α (RAR-α) and retinoid X receptor-α (RXR-α), was determined using ligand-binding assays. Activator protein-1 (AP-1) activity was measured using a luciferase reporter assay. Western blot analysis was used to determine cyclin E, Bcl-2 and Bax protein expression. ATPR preferentially bound RXR-α (0.04 nM) as compared with RAR-α (20.96 nM). Although both ATRA and ATPR inhibited the growth of AGS, MKN-74 and SC-M1 cells in a dose-dependent manner, a significantly greater inhibitory effect was observed with treatment with 5 and 500 µM ATPR for 3 days (P<0.05). In addition, ATPR (50 µM), but not ATRA, significantly increased the population of AGS and MKN-74 cells in the subG1 phase and decreased the Bcl-2/Bax ratio (P<0.05). Furthermore, in MNK-74 and SC-M1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) and 5 or 10 µM of ATPR significantly suppressed the activity of the AP-1 reporter as compared to treatment with ATRA (P<0.05). Thus, ATPR inhibits cancer cell proliferation to a greater extent compared to ATRA, possibly through the RXR-mediated inhibition of AP-1 activity.
Assuntos
Retinoides/farmacologia , Neoplasias Gástricas/patologia , Tretinoína/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Gástricas/metabolismo , Fator de Transcrição AP-1/antagonistas & inibidores , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Tretinoína/análogos & derivadosRESUMO
Because of increased insensitivity or resistance to chemical treatment in tumor patients, specific apoptotic gene silence may provide a rational approach for the development of novel therapeutic strategies. This study was to investigate whether downregulation of Bcl-2 expression by small interfering RNA (siRNA) against the Bcl-2 gene would enhance the apoptosis and sensitivity of gastric adenocarcinoma SGC-7901 cell to 5-Fluorouracil. Transfections of SGC-7901 cells with siRNA were performed using cationic liposomes. Sequence-specific downregulation of Bcl-2 expression was measured by RT-PCR and Western blot analysis. Cell proliferation assay was determined by MTT assay and apoptotic cell rates were determined by flow cytometry assay. Results showed that the siRNA could downregulate Bcl-2 expression, which increased apoptosis and sensitivity of SGC-7901 cell to 5-Fluorouracil (P<0.05). This study indicated that inhibition of Bcl-2 expression by siRNA would be useful a new useful protocol to increase the effect of 5-Fluorouracil on treatment of gastric adenocarcinoma, which may play an important role in developing novel therapeutic strategies in the future.