RESUMO
Compound FLZ is a synthetic novel derivate of natural squamosamide, which has potent neuroprotective effects based on our previous study. We are now aiming to investigate the effects of FLZ on cerebral blood flow (CBF), infarct volume, neurological function, heat shock protein 70 (Hsp70), and Hsp27 expression in transient focal ischemia. For this goal, an animal model of middle cerebral artery occlusion (MCAO) for 2h followed by reperfusion was used, and animals received low or high doses of FLZ (150 or 300mg/kg), orally 10min after MCAO onset. The results show that the infarct volume was 32.7% for the vehicle control group, and reduced to 17.6 and 12.8% for the low and high dose FLZ-treated groups, respectively. FLZ treatment also significantly improved the neurobehavioral score from 2.6 in the vehicle control group to 1.0 and 0.9 in the low and high dose groups, respectively. Further, FLZ significantly induced Hsp27 over-expression and reduced over-expression of HSP70, a sensitive marker of acute ischemia, in ipsilateral cortex by a dose-dependent manner. In addition, CBF was quantified using laser-Doppler flowmetry. During ischemia, regional CBF (rCBF) was improved from approximately 30% to over 50% of the baseline and the reperfusion-induced hyperemia was reduced in both FLZ dosage groups. Particularly, high dose FLZ reduced rCBF during hyperemia by 30%. In conclusion, FLZ (150 and 300mg/kg) can significantly reduce the infarct volume and improve neurobehavioral deficits in a rat MCAO model, most likely through improving CBF in the penumbra and enhancing Hsp27 expression.
Assuntos
Benzenoacetamidas/administração & dosagem , Isquemia Encefálica/fisiopatologia , Córtex Cerebral/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Proteínas de Choque Térmico HSP27/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Fenóis/administração & dosagem , Animais , Isquemia Encefálica/patologia , Isquemia Encefálica/prevenção & controle , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Masculino , Ratos , Ratos WistarRESUMO
The rhizomes of Gastrodia elata have been used for the treatment of insomnia in oriental countries. N6-(4-hydroxybenzyl) adenine riboside (NHBA) was originally isolated from G. elata. For the first time we report a detailed study on the effects and mechanisms of NHBA on its sedative and hypnotic activity. Adenosine, an endogenous sleep factor, regulates sleep-wake cycle via interacting with adenosine A1/A(2A) receptors. Using radioligand binding studies and cAMP accumulation assays, our results show that NHBA may be a functional ligand for the adenosine A1 and A(2A) receptors. NHBA significantly decreases spontaneous locomotor activity and potentiates the hypnotic effect of sodium pentobarbital in mice. Sleep architecture analyses reveal that NHBA significantly decreases wakefulness time and increases NREM sleep times. However, NHBA does not affect the amount of REM sleep. Pretreatment with the adenosine A1 receptor antagonist DPCPX or the A(2A) receptor antagonist SCH 58261 significantly reverses the increase in sleeping time induced by NHBA in sodium pentobarbital treated mice. Immunohistochemical studies show that NHBA increases c-Fos expression in GABAergic neurons of the ventrolateral preoptic area (VLPO), which suggests that NHBA activates the sleep center in the anterior hypothalamus. Altogether, these results indicate that NHBA produces significant sedative and hypnotic effects. Such effects might be mediated by the activation of adenosine A1/A(2A) receptors and stimulation of the sleep center VLPO.
Assuntos
Adenosina/análogos & derivados , Gastrodia/química , Hipnóticos e Sedativos , Pentobarbital/farmacologia , Adenosina/isolamento & purificação , Adenosina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Células CHO , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Eletroencefalografia/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Membranas/efeitos dos fármacos , Membranas/enzimologia , Membranas/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Equilíbrio Postural/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Wistar , Receptor A1 de Adenosina/efeitos dos fármacos , Receptor A1 de Adenosina/metabolismo , Receptor A2A de Adenosina/efeitos dos fármacos , Receptor A2A de Adenosina/metabolismo , Receptores Purinérgicos P1/efeitos dos fármacos , Reflexo/efeitos dos fármacosRESUMO
GL331, a topoisomerase II inhibitor, has been found to trigger DNA damage response (DDR) to induce cell cycle arrest. However, the underlying mechanism has not yet been fully understood. This study investigated the molecular mechanism involved in the GL331-induced cell cycle arrest via DDR in human hepatocellular carcinoma HepG2 cells. As a result, GL331 could induce S arrest and up-regulate the phosphorylation of the histone H2AX variant (γ-H2AX). Ataxia telangiectasia mutated protein kinase (ATM) was activated by GL331 through its autophosphorylation at Ser1981, which led to the activation of DNA damage signaling pathways including p53/p21 and Chk2/Cdc25A cascades. The DNA damage cascades triggered by GL331 finally induced the inactivation of cyclin A/Cdk2 complexes to some extent. These phenomena could be reversed by ATM siRNA, followed by a partial disruption of S arrest. The present results suggested that the S arrest induced by GL331 via DDR was in an ATM-dependent manner to some degree.
Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Etoposídeo/análogos & derivados , Inibidores da Topoisomerase II/farmacologia , Etoposídeo/química , Etoposídeo/farmacologia , Células Hep G2 , Histonas/metabolismo , Humanos , Estrutura MolecularRESUMO
A series of new bisbenzylisoquinoline alkaloids was partially synthesized from tetrandrine and fangchinoline and evaluated for their ability to reverse P-glycoprotein-mediated multidrug resistance (MDR) in cancer cells. All the test compounds increased the intracellular accumulation rate of rhodamine 123 in MDR cells (Bel7402 and HCT8), and most exhibited more potent MDR-reversing activity relative to the reference compound verapamil. Compounds 8, 10, 13, and 14 enhanced intracellular accumulation of doxorubicin in Bel7402 and HCT8 cells.
Assuntos
Alcaloides/síntese química , Alcaloides/farmacologia , Benzilisoquinolinas/síntese química , Benzilisoquinolinas/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , Alcaloides/química , Benzilisoquinolinas/química , Doxorrubicina/farmacologia , Humanos , Estrutura Molecular , Rodamina 123/análiseRESUMO
The aim of this study was to investigate the protective effects of N-[2-(4-hydroxy-phenyl)-ethyl]-2-(2,5-dimethoxy-phenyl)-3-(3-methoxy-4-hydroxy-phenyl)-acrylamide (FLZ), a synthetic squamosamide cyclic derivative, on senescent mice induced by D: -galactose/NaNO(2) (120/90 mg/kg, i.p.) once daily for 60 days. FLZ (75 and 150 mg/kg) was orally administered once daily for 30 days after D: -galactose/NaNO(2) treatment for 30 days. The cognitive function of mice was evaluated with step-down task. The brain biomarkers including monoamine oxidase B (MAO-B), glutathione peroxidase (GSH-px), and malondialdehyde (MDA) were determined according to the manufacturer's instructions. The expression of acetylcholinesterase (ACh-E) and choline acetyltransferase (ChAT) protein in the CA1 region of hippocampus were counted by immunohistochemical staining. The results showed that the cognitive function, GSH-px activity in the brain, and the expression of ACh-E and ChAT in the CA1 region of hippocampus were significantly decreased, while MAO-B activity and MDA level in the brain were increased in senescent mice compared with the control mice. FLZ treatment prolonged the step-down latency and decreased the number of step-down errors in the senescent mice. In addition, FLZ treatment increased the GSH-px activity and the expression of ACh-E and ChAT in the hippocampus and decreased the MDA level and MAO-B activity compared with the senescent mice without drug administration. These findings suggested that FLZ improves the performance in the step-down task and the pathological alternations in senescent mice.
Assuntos
Envelhecimento/fisiologia , Benzenoacetamidas/uso terapêutico , Transtornos da Memória/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Fenóis/uso terapêutico , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Benzenoacetamidas/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Encéfalo/fisiopatologia , Modelos Animais de Doenças , Galactose , Glutationa Peroxidase/metabolismo , Masculino , Malondialdeído/metabolismo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/fisiopatologia , Camundongos , Camundongos Endogâmicos ICR , Monoaminoxidase/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Nitrito de SódioRESUMO
Currently, multi-drug resistance (MDR) to anticancer drugs is a major obstacle to successful treatment of cancer. Looking for novel compounds with anti-MDR activity is an effectively way to overcome cancer drug resistance. Here, we found that H1, a novel derivate of Tetrandrine, displayed anti-MDR activity in vitro and in vivo. Average resistant factor of H1 is only 1.6. In KB and KBv200 cancer cells xenograft mice, H1 also displayed favorable anti-MDR activity. It could induce typical apoptosis as indicated by morphologic changes, DNA fragmentation in sensitive and resistant cancer cells. Further studies showed that H1 treatment resulted in the increase of ROS generation, elevation of the Bax/Bcl-2 ratio, loss of mitochondrial transmembrane potential (ΔΨ(m)), release of cytochrome c and AIF from mitochondria into cytosol, and activation of caspase-9 and caspase-3, but had no effect on activation of caspase-8 and the expression of Fas/FasL. On the other hand, H1 also inhibited survival pathways such as the activation of Erk1/2 and Akt1/2. In conclusion, H1 exerts good anti-MDR activity in vitro and in vivo, its mechanisms may be associated with initiating intrinsic apoptosis pathway and inhibiting the activation of Erk1/2 and Akt1/2. These findings further support the potential of H1 to be used in clinical trial of MDR cancer treatment.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Antineoplásicos/química , Benzilisoquinolinas/química , Caspase 3/metabolismo , Caspase 9/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citocromos c/metabolismo , Ativação Enzimática , Feminino , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Heat shock proteins (HSPs) play an essential role in various neurodegenerative diseases. Manipulation of upregulation of HSPs in cells has been demonstrated to provide a therapeutic strategy to counteract the misfolding and aggregation of proteins that resulted in neurodegenerative disease. Our previous studies have shown that FLZ, a synthetic novel derivative of squamosamide from a Chinese herb, had potent neuroprotective effect against several experimental Parkinson's disease (PD) models. However, the mechanism of its neuroprotective effect is still not clarified. The present study demonstrated that FLZ induced HSP27 and HSP70 proteins and mRNA expression in a time- and dose-dependent manner in SH-SY5Y cells. Further studies showed that FLZ treatment stimulated the activation of heat shock factor 1 (HSF1) and its regulatory kinase Akt. Inactivation of Akt pathway by the PI3K inhibitor LY294002 blocked the expression of HSP27 and HSP70 induced by FLZ. Moreover, the inducing effects of FLZ on HSP27, HSP70, and HSF1 were all blocked by quercetin, an inhibitor of HSP biosynthesis. The cytoprotective effect of HSP27/HSP70 induced by FLZ against MPP(+) was assessed in SH-SY5Y cells. The pretreatment of FLZ significantly induced the accumulations of HSP27/HSP70 and suppressed the apoptosis caused by MPP(+) in SH-SY5Y cells. However, the protective effects of FLZ against MPP(+) were significantly blocked by quercetin, which indicated that the cytoprotective action of FLZ against MPP(+)-induced apoptosis is at least partially mediated by its induction of HSP27/HSP70. These results provide new evidence for elucidating the mechanism of the neuroprotective effect of FLZ against PD.
Assuntos
Apoptose/efeitos dos fármacos , Benzenoacetamidas/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , 1-Metil-4-fenilpiridínio/toxicidade , Western Blotting , Linhagem Celular , Proteínas de Ligação a DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Ativação Enzimática/efeitos dos fármacos , Neurotoxina Derivada de Eosinófilo/toxicidade , Proteínas de Choque Térmico HSP27/biossíntese , Proteínas de Choque Térmico HSP70/biossíntese , Fatores de Transcrição de Choque Térmico , Humanos , Microscopia de Fluorescência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismoRESUMO
OBJECTIVE: The purpose of this study was to assess the effect of long-term deprivation of gonadal hormone on brain aging in mice to develop a model of gonadectomy-accelerated brain aging. METHODS: Male and female mice at 2 months old were orchiectomized (ORX) or ovarectomized (OVX) bilaterally or sham operated, and then they were fed for 10 months. The spatial learning and memory ability was tested using Morris Water Maze. The biomarkers of brain neuropathology were examined by Western blotting and immunohistochemistry. RESULTS: Ovarectomy mildly impaired spatial learning and memory of mice, while the impairment in ORX-mice was not significant. The amount of Nissl bodies decreased in the hippocampus and cortex of gonadectomied mice. The expression of beta-amyloid (Aß), beta-site APP cleaving enzyme 1 and phosphorylated-Tau increased in gonadectomied mice. Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) decreased in the brain of OVX-mice, but neurotrophin-3 (NT-3) showed no change. We detected no decrease of NGF, BDNF or NT-3 in ORX-mice. TrkA expression decreased and p75(NTR) increased in the brain of gonadectomied mice. In all the above tests, there were no significant differences between young (2 months old) and sham operated (12 months old) mice. Alternations in the brain aging parameters were more obvious in OVX-mice than in ORX-mice. CONCLUSION: Long-term gonadal hormone deprivation by young-age gonadectomy accelerated mouse brain aging, which could serve as a valuable mouse model to study brain aging and aging-related pathological changes.
Assuntos
Envelhecimento/metabolismo , Envelhecimento/psicologia , Encéfalo/metabolismo , Hormônios Gonadais/deficiência , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Fator Neurotrófico Derivado do Encéfalo , Feminino , Hormônios Gonadais/efeitos adversos , Masculino , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos ICR , Fatores de Crescimento Neural/metabolismo , Orquiectomia/psicologia , Ovariectomia/psicologia , Receptor de Fator de Crescimento Neural/metabolismo , Receptor trkA/metabolismo , Proteínas tau/metabolismoRESUMO
p53 (encoded by TP53) is undoubtedly one of the most extensively studied genes and proteins. It is a highly potent transcription factor which, under normal circumstances, is maintained at low level. Both genotoxic and non-genotoxic stresses can induce p53 stabilized leading to changes in the expression of p53-responsive genes. The biological outcome inducing this pathway can be either growth arrest and apoptosis or senescence to maintain the integrity of the genome or to delete the damaged cells. The biochemical activity of p53 itself and the cellular environment govern the choice between these outcomes in a cell type- and stress-specific manner. So, p53 is a pivotal tumour suppressor and a mainstay of our body's natural anticancer defence. This review could provide some useful information for further study on the mechanisms of tumorigenesis and its progression, and also could contribute to the discovery of antitumor agents.
Assuntos
Dano ao DNA , Reparo do DNA , Genes p53 , Proteína Supressora de Tumor p53 , Animais , Apoptose , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologiaRESUMO
Eighteen schizandrin A derivatives, possessing an acyl group at 7-OH and/or halogen(s) at C-4 and C-11, were designed and synthesized for evaluation of their in vitro ability to inhibit multidrug resistance (MDR). They exhibit weak ability to restore the intracellular Rhodamine 123 in human hepatocarcinoma MDR cell lines Bel7402 and HCT8 relative to the reference drug verapamil.
Assuntos
Ciclo-Octanos/síntese química , Ciclo-Octanos/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Lignanas/síntese química , Lignanas/farmacologia , Compostos Policíclicos/síntese química , Compostos Policíclicos/farmacologia , Ciclo-Octanos/química , Humanos , Lignanas/química , Estrutura Molecular , Compostos Policíclicos/química , Rodamina 123/análise , Schisandra/química , Relação Estrutura-AtividadeRESUMO
This paper investigates the effect of natural scutellarin on acute lung injury (ALI) induced by Escherichia coli endotoxin lipopolysaccharide (LPS) in mice and its mechanism of action. Mouse ALI was induced by the injection of LPS (15 mg/kg) via the tail vein, and mice were intraperitoneally injected with 50 and 25 mg/kg of scutellarin before the LPS injection. The lung index, serum NO2(-)/NO3(-), and tumor necrosis factor-alpha (TNF-alpha) levels were determined using kits. The lung lesions were examined by light microscope. The mRNA levels of TNF-alpha, inducible nitric oxide synthase (iNOS), and FasL in pulmonary tissues were detected by RT-PCR. c-Fos, c-Jun, IkappaB, and iNOS proteins were detected by the western blotting method. Pretreatment with 25 and 50 mg/kg of scutellarin significantly reduced lung injury induced by LPS, which expressed in the decrease in lung morphological lesions, serum NO2(-)/NO3(-), TNF-alpha levels, lactate dehydrogenase release, and total protein in the lavage fluid of bronchoalveolar of the lung. The mRNA level of TNF-alpha, iNOS, the protein content of c-Fos, iNOS, and the activation of NF-kappaB in pulmonary tissues were all inhibited, while the lung glutathione level increased. In conclusion, scutellarin has protective action against LPS-induced lung damage in mice, and its underlying mechanism might be the inhibition of IkappaB alpha degradation and the expression of TNF-alpha mRNA.
Assuntos
Lesão Pulmonar Aguda/induzido quimicamente , Apigenina/farmacologia , Glucuronatos/farmacologia , Lipopolissacarídeos/farmacologia , NF-kappa B/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Actinas/sangue , Actinas/metabolismo , Animais , Endotoxinas/farmacologia , Escherichia coli/química , Genes fos/efeitos dos fármacos , Pulmão/metabolismo , Camundongos , Estrutura Molecular , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/sangue , Óxido Nítrico Sintase Tipo II/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/sangueRESUMO
Heat shock proteins (HSPs), the best known endogenous factors, play important roles in the cytoprotection and repair of cells and tissues against the harmful effects of stress and insults. In this study, RNAi technology was used to identify whether HSP70 was involved in the protection of bicyclol against d-galactosamine (d-GaIN)-induced apoptosis in HepG2 cells. As a result, bicyclol induced HSP70 in a time- and dose-dependent manner in HepG2 cells. Bicyclol markedly alleviated apoptosis and caspase-3 activity in HepG2 cells intoxicated by d-GaIN. The degradation of inhibitory kappa B, phosphorylation of inhibitory kappa B kinase, nuclear factor kappa B (NF-kappaB) nuclear translocation, and DNA-binding activity were all inhibited by bicyclol in HepG2 cells intoxicated by d-GaIN. In addition, bicyclol decreased the nitric oxide production and inducible nitric oxide synthase (iNOS) expression. The inhibitory effects of bicyclol on all the above biomarkers were attenuated when the HSP70 gene was silenced accordingly. Our data also showed that MG132 (inhibitor of NF-kappaB) and NG-nitro-l-arginine methyl ester (inhibitor of iNOS) inhibited hepatocyte apoptosis induced by d-GaIN. These in vitro results suggested that HSP70 partially contributed to the hepatoprotection of bicyclol through suppressing the NF-kappaB-iNOS pathway.
Assuntos
Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Galactosamina/farmacologia , Proteínas de Choque Térmico HSP70/metabolismo , NF-kappa B/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Caspase 3/metabolismo , Relação Dose-Resposta a Droga , Galactosamina/química , Proteínas de Choque Térmico HSP70/genética , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Estrutura Molecular , NG-Nitroarginina Metil Éster/farmacologia , EstereoisomerismoRESUMO
AIM: To study the inducing effect of bicyclol on heat shock protein 27 (HSP27) and its role on anti-apoptosis in HepG2 cells intoxicated with D-galactosamine (D-GaIN). METHODS: HepG2 cells were treated with various concentrations of bicyclol and then subjected to D-GaIN intoxication. Apoptosis was assayed by hoechst 33258 staining and flow cytometry analysis. HSP27, cytochrome c, apoptosis inducing factor (AIF) and c-Jun N-terminal kinase (JNK) were assayed by Western blot. Heat shock factor 1 (HSF1) was determined by electrophoretic mobility shift assay and the interactions of HSP27 with cytochrome c and AIF were detected by co-immunoprecipitation. RESULTS: The results showed that bicyclol induced HSP27 protein and mRNA expression in HepG2 cells in both time- and dose-dependent manners (the maximal response: 1.23 fold increase at 100 micromol/L). Bicyclol treatment stimulated HSF1 activation and increased the HSF1-HSE binding activity (the maximal response: 2.1 fold increase at 100 micromol/L). This inducing effect of bicyclol on HSP27 and HSF1 was markedly blocked by quercetin. Pretreatment of the cells with bicyclol markedly attenuated D-GaIN-induced apoptosis and the release of cytochrome c and AIF from mitochondria. The induced HSP27 by bicyclol suppressed the activity of caspase-3 and the phosphorylation of JNK caused by D-GaIN in HepG2 cells. All the above effect of bicyclol against D-GaIN-induced hepatocytes apoptosis were significantly reversed by quercetin. CONCLUSION: HSP27 is involved in the anti-hepatocytes apoptosis of bicyclol, and this effect of bicyclol-induced HSP27 is mainly through inhibition of mitochondria and JNK apoptotic pathways.
Assuntos
Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Galactosamina/farmacologia , Proteínas de Choque Térmico HSP27/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Sequência de Bases , Western Blotting , Linhagem Celular Tumoral , Primers do DNA , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Proteínas de Choque Térmico HSP27/genética , Humanos , Imunoprecipitação , Mitocôndrias Hepáticas/metabolismoRESUMO
AIM: The aim of this study was to study the effects of compound FLZ, a novel cyclic derivative of squamosamide from Annona glabra, on brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)/cAMP response element-binding protein (CREB) signaling and neuronal apoptosis in the hippocampus of the amyloid precursor protein (APP)/presenilin-1 (PS1) double transgenic mice. METHODS: APP/PS1 mice at the age of 5 months and age-matched wild-type mice (WT) were intragastrically administered FLZ (150 mg/kg) or vehicle [0.05% carboxymethyl cellulose sodium (CMC-Na)] daily for 20 weeks. The levels of BDNF in the hippocampus of WT and APP/PS1 mice were then measured by immunohistochemistry and Western blot analysis. Neuronal apoptosis in mouse hippocampus was detected by Nissl staining. Expression of NGF, NT3, pTrkB (Tyr515)/TrkB, pAkt (Ser473)/Akt, pERK/ERK, pCREB (Ser133)/CREB, Bcl-2/Bax, and active caspase-3 fragment/caspase-3 in the hippocampus of WT and APP/PS1 mice was detected by Western blot analysis. RESULTS: Compared with vehicle-treated APP/PS1 mice, FLZ (150 mg/kg) significantly increased BDNF and NT3 expression in the hippocampus of APP/PS1 mice. In addition, FLZ promoted BDNF high-affinity receptor TrkB phosphorylation and activated its downstream ERK, thus increasing phosphorylation of CREB at Ser133 in the hippocampus of APP/PS1 mice. Moreover, FLZ showed neuroprotective effects on neuronal apoptosis by increasing the Bcl-2/Bax ratio and decreasing the active caspase-3 fragment/caspase-3 ratio in the hippocampus of APP/PS1 mice. CONCLUSION: FLZ exerted neuroprotection at least partly through enhancing the BDNF/TrkB/CREB pathway and inhibiting neuronal apoptosis in APP/PS1 mice, which suggests that FLZ can be explored as a potential therapeutic agent in long-term Alzheimer's disease therapy.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Benzenoacetamidas/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Fármacos Neuroprotetores/farmacologia , Fenóis/farmacologia , Receptor trkB/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Apoptose/efeitos dos fármacos , Benzenoacetamidas/uso terapêutico , Caspase 3/metabolismo , Feminino , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Fenóis/uso terapêutico , Presenilina-1/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína X Associada a bcl-2/metabolismoRESUMO
5-Bromotetrandrine (BrTet) was shown to overcome multi-drug resistance (MDR) in vitro and in vivo by inhibiting the overexpression and efflux function of P-glycoprotein in our previous study. The purpose of the present study was to evaluate the effect of BrTet on the sensitivity of doxorubicin (Dox) induced apoptosis in intrinsic resistant human hepatic cancer Bel7402 cells. The cells were treated with non-toxic concentrations of BrTet (1 microM, 2 microM, 4 microM) or the positive control drug verapamil (Vrp) (10 microM) for 24h followed by a low dose Dox (3 microM) for 24 h. The results showed that BrTet pretreatment followed by Dox led to typical apoptotic characters as indicated by morphologic changes, DNA fragmentation and changes in cell cycle, while the same dose of BrTet, Vrp and Dox alone did not induce apoptosis in Bel7402 cells. In addition, the pretreatment of BrTet or Vrp followed by Dox induced activation of caspase-3, release of cytochrome c and AIF from mitochondria into cytosol, loss of mitochondrial transmembrane potential (DeltaPsi(m)) and elevation of Bax/Bcl-2 ratio, with no effect on activation of caspase-8 and the expression of Fas/FasL. In conclusion, BrTet pretreatment enhanced the sensitivity of Dox to induce apoptosis by causing loss of DeltaPsi(m) and elevating the ratio of Bax/Bcl-2, eventually activated mitochondrial apoptotic pathway. These findings further support the potential of BrTet to be used in clinical trail of cancer treatment.
Assuntos
Apoptose/efeitos dos fármacos , Benzilisoquinolinas/farmacologia , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Benzilisoquinolinas/administração & dosagem , Caspase 3/biossíntese , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Sinergismo Farmacológico , Ativação Enzimática , Humanos , Receptores de Morte Celular/metabolismo , Verapamil/farmacologiaRESUMO
Many major neurodegenerative diseases are associated with proteins misfolding and aggregation, which are also called "neurodegenerative conformational disease". The interaction of gene mutation and environmental factors are probably primary events resulting in oligomer and aggregate formations of proteins. Moreover, the dysfunctions of protein control systems, i.e. the ubiquitin-proteasome system and autophagy-lysosomal system, also contribute to the neurodegenerative process. The present review mainly summarizes protein misfolding and aggregation in the development of neurodegenerative conformational disease and the underling mechanisms, as well as upregulation of heatshock proteins as a promising treatment method for this kind of disease.
Assuntos
Proteínas de Choque Térmico/metabolismo , Doenças Neurodegenerativas/metabolismo , Dobramento de Proteína , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Annona/química , Autofagia , Benzenoacetamidas/isolamento & purificação , Benzenoacetamidas/uso terapêutico , Proteínas de Choque Térmico/fisiologia , Humanos , Mutação , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Fenóis/isolamento & purificação , Fenóis/uso terapêutico , Plantas Medicinais/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismoRESUMO
The aim of the present study is to investigate the effect and mechanism of Coeloglossum viride var. bracteatum extract (CE) on scopolamine-induced learning and memory deficits. Learning and memory deficits of mice were evaluated by step-down passive avoidance test. Long-term potentiation of rats was detected in the dentate gyrus of hippocampus. Brain acetylcholinesterase (AChE) and choline acetyltransferase (ChAT) activities were also determined. The results showed that scopolamine impaired learning and memory performance and LTP induction in hippocampus. Oral administration of CE (5, 10, and 20 mg x kg(-1)) significantly alleviated scopolamine-induced memory deficits measured by step-down test (P < 0.05). CE (5 mg x kg(-1), ip) significantly reversed the inhibitory effect of scopolamine on LTP in rats. In addition, CE was found to increase the activity of ChAT in rat brain. These results suggested that CE could alleviate scopolamine-induced learning and memory deficits, which might be due to the LTP-improvement and ChAT activity enhancement.
Assuntos
Glucosídeos/farmacologia , Aprendizagem/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Transtornos da Memória , Orchidaceae/química , Succinatos/farmacologia , Acetilcolinesterase/metabolismo , Animais , Encéfalo/enzimologia , Colina O-Acetiltransferase/metabolismo , Giro Denteado/fisiopatologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Glucosídeos/isolamento & purificação , Hipocampo/fisiopatologia , Masculino , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/enzimologia , Transtornos da Memória/fisiopatologia , Camundongos , Plantas Medicinais/química , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Escopolamina , Succinatos/isolamento & purificaçãoRESUMO
AIM: The aim of the present study was to assess the effects of N-[2-(4-hydroxyphenyl)ethyl]-2-(2,5-dimethoxyphenyl)-3-(3-methoxy-4-hydroxyphenyl) acrylamide (compound FLZ), a novel synthetic analogue of squamosamide, on the dysfunction of rat brain mitochondria induced by Abeta(25-35) in vitro. METHODS: Isolated rat brain mitochondria were incubated with aged Abeta(25-35) for 30 min in the presence and absence of FLZ (1-100 micromol/L). The activities of key mitochondrial enzymes, the production of hydrogen peroxide (H(2)O(2)) and superoxide anion (O2*-), and the levels of glutathione (GSH) in mitochondria were examined. Mitochondrial swelling and the release of cytochrome c from mitochondria were assessed by biochemical and Western blot methods, respectively. RESULTS: Incubation of mitochondria with aged Abeta(25-35) inhibited the activities of alpha-ketoglutarate dehydrogenase (alpha-KGDH), pyruvate dehydrogenase (PDH) and respiratory chain complex IV. It also resulted in increased H(2)O(2) and (O2*-) production, and decreased the GSH level in mitochondria. Furthermore, it induced mitochondrial swelling and cytochrome c release from the mitochondria. The addition of FLZ (100 micromol/L) prior to treatment with Abeta(25-35) significantly prevented these toxic effects of Abeta(25-35) on the mitochondria. CONCLUSION: FLZ has a protective effect against Abeta(25-35)-induced mitochondrial dysfunction in vitro.
Assuntos
Peptídeos beta-Amiloides/efeitos adversos , Benzenoacetamidas/farmacologia , Encéfalo/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fragmentos de Peptídeos/efeitos adversos , Fenóis/farmacologia , Animais , Citocromos c/metabolismo , Glutationa/metabolismo , Técnicas In Vitro , Complexo Cetoglutarato Desidrogenase/metabolismo , Masculino , Dilatação Mitocondrial/efeitos dos fármacos , Piruvato Desidrogenase (Lipoamida)/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
Heat shock proteins (HSPs) are molecular chaperones critical for cell survival under adverse environmental conditions and for normal cellular homeostasis. Bicyclol, a novel antihepatitis drug, has been shown to protect against liver injury in animals. However, it is unclear how bicyclol protects against liver injury. We recently found that bicyclol is an inducer of HSPs. We wondered whether bicyclol regulated the expression of HSPs to produce a liver protection in vivo. Thus, this study was designed to address these questions using a mouse model with concanavalin A (ConA)-induced liver injury. Oral administration of bicyclol markedly alleviated ConA-caused liver injury in mice as indicated by the reduction of serum aminotransferases, liver necrosis, and the release of cytochrome c and apoptosis-inducing factor from mitochondria and hepatic DNA fragmentation. Correlated with this, bicyclol induced the increase of mRNA and protein levels of hepatic 27- and 70-kDa HSPs (HSP27 and HSP70) in the mice. Correspondingly, the elevated HSP27 and HSP70 suppressed inhibitor kappaB degradation and nuclear factor kappaB (NF-kappaB) activation that were caused by ConA. The protective effects of bicyclol on ConA-induced mouse liver injury were markedly attenuated by quercetin, an inhibitor of HSPs synthesis. Our results suggest that the antihepatitis drug bicyclol may protect against liver injury by inducing the expression of hepatic HSP27 and HSP70 and consequently inhibit the transcription factor NF-kappaB-mediated apoptosis and necrosis in liver tissue.