RESUMO
BACKGROUND: A rotator cuff tear (RCT) induces fatty acid-binding protein 4 (FABP4) expression, resulting in ectopic fat accumulation in the rotator cuff muscle. PURPOSE: To evaluate whether FABP4 inhibition reduces fatty infiltration and improves muscle physiology after RCT in a rat model. STUDY DESIGN: Controlled laboratory study. METHODS: Human supraspinatus muscle and deltoid muscle tissues were acquired from patients with RCTs during arthroscopic surgery, and FABP4 expression in the supraspinatus muscle was evaluated as compared with the intact deltoid muscle. A rat RCT model was established by detaching the supraspinatus tendon, after which a specific FABP4 inhibitor was locally injected into the supraspinatus muscle 4 times at 3-day intervals starting 2 weeks after the surgery. Body weight and blood glucose levels were measured at 2 and 4 weeks after the RCT, and the mRNA and protein expressions of various target molecules (including FABP4), histological changes, and biomechanical tensile strength were assessed in the supraspinatus muscles at 4 weeks after the RCT. RESULTS: The expression of human FABP4 was significantly increased in the torn rotator cuff muscle as compared with the intact deltoid muscle. In the rat model, the mRNA and protein expressions of FABP4 and HIF1α were significantly increased by the RCT as compared with the control. The FABP4 inhibitor treatment significantly decreased FABP4 expression when compared with the vehicle treatment; however, HIF1α expression was not significantly decreased versus the vehicle treatment. Histologically, RCT induced noticeable muscle fatty infiltration, which was remarkably reduced by the local injection of the FABP4 inhibitor. Biomechanically, the tensile strength of the rotator cuff muscle after the RCT was significantly improved by the FABP4 inhibitor in terms of load to failure and total energy to failure. CONCLUSION: RCT induces FABP4 expression in human and rat rotator cuff muscles. The FABP4 inhibitor drastically decreased the histological fatty infiltration caused by RCT and improved the tensile strength of the rotator cuff muscle. CLINICAL RELEVANCE: FABP4 inhibitor may have a beneficial effect on the muscle quality after RCT.
Assuntos
Compostos de Bifenilo/uso terapêutico , Proteínas de Ligação a Ácido Graxo/antagonistas & inibidores , Pirazóis/uso terapêutico , Lesões do Manguito Rotador/metabolismo , Manguito Rotador/efeitos dos fármacos , Adiposidade/efeitos dos fármacos , Animais , Compostos de Bifenilo/farmacologia , Músculo Deltoide/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Proteínas de Ligação a Ácido Graxo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/efeitos dos fármacos , Pirazóis/farmacologia , RNA Mensageiro , Ratos , Ratos Sprague-Dawley , Manguito Rotador/metabolismo , Lesões do Manguito Rotador/tratamento farmacológicoRESUMO
Obesity-associated metabolic alterations are closely linked to low-grade inflammation in peripheral organs, in which macrophages play a central role. Using genetic labeling of myeloid lineage cells, we show that hypothalamic macrophages normally reside in the perivascular area and circumventricular organ median eminence. Chronic consumption of a high-fat diet (HFD) induces expansion of the monocyte-derived macrophage pool in the hypothalamic arcuate nucleus (ARC), which is significantly attributed to enhanced proliferation of macrophages. Notably, inducible nitric oxide synthase (iNOS) is robustly activated in ARC macrophages of HFD-fed obese mice. Hypothalamic macrophage iNOS inhibition completely abrogates macrophage accumulation and activation, proinflammatory cytokine overproduction, reactive astrogliosis, blood-brain-barrier permeability, and lipid accumulation in the ARC of obese mice. Moreover, central iNOS inhibition improves obesity-induced alterations in systemic glucose metabolism without affecting adiposity. Our findings suggest a critical role for hypothalamic macrophage-expressed iNOS in hypothalamic inflammation and abnormal glucose metabolism in cases of overnutrition-induced obesity.
Assuntos
Hipotálamo/patologia , Inflamação/enzimologia , Macrófagos/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Obesidade/enzimologia , Animais , Núcleo Arqueado do Hipotálamo/patologia , Barreira Hematoencefálica/patologia , Proliferação de Células , Dieta Hiperlipídica , Glucose/metabolismo , Inflamação/patologia , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Obesidade/patologia , Células RAW 264.7RESUMO
Various self-healing methods for concrete, such as the use of supplementary cementitious materials, adhesive agents, mineral admixtures, and bacteria, have been suggested to date, and each of these has merits and demerits. Among these, however, the use of cementitious materials may be appropriate due to their good healing efficiency, low cost, and compatibility with the cement matrix. In this study, granulation and coating methods were applied to a new cementitious composite material. The self-healing property of these materials was controlled by the polyvinyl alcohol (PVA) coating until cracks were created. Water dissolved the PVA coating after entering through the cracks, and reacted with the healing materials to generate healing products. The self-healing performance was evaluated at various elapsed times through the measurement of the crack widths, visual observation, and examination of the microscopic images. Simultaneously, a water permeability test was performed and the dynamic modulus of elasticity was measured to verify the recovery of the cracks. In addition, the healing products that had been formed in the cracks were analyzed via X-ray diffraction (XRD) and scanning electron microscopy (SEM).
RESUMO
The Artemisia group of plants has long been used as a traditional remedy for various conditions. The present study assessed the sleep-promoting (sedative-hypnotic) effects of Artemisia capillaris Thunberg (A. capillaris), and elucidated a possible mechanism behind its effect. ICR mice were given A. capillaris extract (oral) at different dosages (50, 100, 200, 300, or 400 mg/kg), distilled water (oral; control), or diazepam (intraperitoneal; reference drug). One hour after administration, locomotion (open-field test) and motor coordination (rota-rod test) were assessed. The extract's effect on pentobarbital-induced sleep was also evaluated. Additionally, electroencephalographic (EEG) recordings were measured in rats. To evaluate a possible mechanism behind its effects, changes in chloride ( Cl (-)) ion influx were measured in human neuroblastoma cells. As compared to the control group, mice treated with A. capillaris demonstrated significantly decreased locomotor activity and impaired motor balance and coordination. The extract also shortened the onset and lengthened the duration of sleep induced by pentobarbital sodium. These effects were comparable to that induced by diazepam. Furthermore, A. capillaris-treated rats showed increased delta and decreased alpha EEG waves; an electroencephalographic pattern indicative of relaxation or sedation. In neuroblastoma cells, the extract dose-dependently increased Cl (-) ion influx, which was blocked by co-administration of bicuculline, a GABAA receptor competitive antagonist, suggesting that its effects are mediated through the GABAA receptor- Cl (-) ion channel complex. Altogether, the results of the present study demonstrate that A. capillaris possesses potent sedative-hypnotic effects, which are probably mediated through potentiation of the GABAA receptor- Cl (-) ion channel complex.
Assuntos
Artemisia/química , Hipnóticos e Sedativos , Extratos Vegetais/farmacologia , Receptores de GABA-A/metabolismo , Administração Oral , Animais , Canais de Cloreto/metabolismo , Cloretos/metabolismo , Relação Dose-Resposta a Droga , Eletroencefalografia/efeitos dos fármacos , Humanos , Locomoção/efeitos dos fármacos , Masculino , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Neuroblastoma/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/isolamento & purificação , Sono/efeitos dos fármacos , Estimulação Química , Células Tumorais CultivadasRESUMO
OBJECTIVE: The hypothalamus is the brain center that controls the energy balance. Anorexigenic proopiomelanocortin (POMC) neurons and orexigenic AgRP neurons in the arcuate nucleus of the hypothalamus plays critical roles in energy balance regulation. FoxO1 is a transcription factor regulated by insulin signaling that is deacetylated by Sirt1, a nicotinamide adenine dinucleotide- (NAD(+) -) dependent deacetylase. Overexpression of insulin-resistant constitutively-nuclear FoxO1 (CN-FoxO1) in POMC neurons leads to obesity, whereas Sirt1 overexpression in POMC neurons leads to leanness. Whether overexpression of Sirt1 in POMC neurons could rescue the obesity caused by insulin-resistant CN-FoxO1 was tested here. METHODS: POMC neuron-specific CN-FoxO1/Sirt1 double-KI (DKI) mice were analyzed. RESULTS: The obese phenotype of CN-FoxO1 KI mice was rescued in male DKI mice. Reduced O2 consumption, increased adiposity, and fewer POMC neurons observed in CN-FoxO1 mice were rescued in male DKI mice without affecting food intake and locomotor activity. Sirt1 overexpression decreased FoxO1 acetylation and protein levels without affecting its nuclear localization in mouse embryonic fibroblasts and hypothalamic N41 cells. CONCLUSIONS: Sirt1 rescues the obesity induced by insulin-resistant CN-FoxO1 in POMC neurons of male mice by decreasing FoxO1 protein through deacetylation. Sirt1 ameliorates obesity caused by a genetic model of central insulin resistance.
Assuntos
Resistência à Insulina , Obesidade/prevenção & controle , Pró-Opiomelanocortina/metabolismo , Sirtuína 1/metabolismo , Animais , Metabolismo Energético/fisiologia , Fatores de Transcrição Forkhead , Hipotálamo/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neurônios/metabolismo , Transdução de Sinais/genéticaRESUMO
Cirsium japonicum (CJ) has been shown to possess antidepressant-like properties. In the present study, we sought to identify which constituent of CJ might be responsible for its antidepressant effects and determine probable mechanism of action. The ethanol extract of CJ was administered to mice then behavioral changes were evaluated in the forced-swimming test (FST) and open-field test (OFT). In addition, its effects on norepinephrine (NE) reuptake and intracellular chloride (Cl(-)) flux were determined, in vitro. The effects of CJ's major constituents (linarin, pectolinarin, chlorogenic acid, luteolin) were also evaluated. CJ showed antidepressant-like effect by significantly reducing immobile behavior of mice in the FST, without increasing locomotor activity in the OFT. CJ had no effect on monoamine (NE) uptake, but it significantly promoted Cl(-) ion influx in human neuroblastoma cells. This CJ-induced Cl(-) influx was significantly blocked by co-administration of the competitive GABAA receptor antagonist, bicuculline. Among the major constituents of the CJ extract, only luteolin produced similar antidepressant-like effect, in vivo, and Cl(-) ion influx, in vitro. Altogether, the present results suggest that the antidepressant-like effect of CJ was most probably induced by its constituent luteolin, mediated through potentiation of the GABAA receptor-Cl(-) ion channel complex.
Assuntos
Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Cirsium/química , Luteolina/farmacologia , Extratos Vegetais/farmacologia , Receptores de GABA-A/metabolismo , Animais , Antidepressivos/isolamento & purificação , Canais de Cloreto/metabolismo , Células HEK293 , Humanos , Luteolina/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/genética , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/metabolismo , Extratos Vegetais/isolamento & purificação , Natação , TransfecçãoRESUMO
AIMS/HYPOTHESIS: Obesity is associated with ageing and increased energy intake, while restriction of energy intake improves health and longevity in multiple organisms; the NAD(+)-dependent deacetylase sirtuin 1 (SIRT1) is implicated in this process. Pro-opiomelanocortin (POMC) and agouti-related peptide (AgRP) neurons in the arcuate nucleus (ARC) of the hypothalamus are critical for energy balance regulation, and the level of SIRT1 protein decreases with age in the ARC. In the current study we tested whether conditional Sirt1 overexpression in mouse POMC or AgRP neurons prevents age-associated weight gain and diet-induced obesity. METHODS: We targeted Sirt1 cDNA sequence into the Rosa26 locus and generated conditional Sirt1 knock-in mice. These mice were crossed with mice harbouring either Pomc-Cre or Agrp-Cre and the metabolic variables, food intake, energy expenditure and sympathetic activity in adipose tissue of the resultant mice were analysed. We also used a hypothalamic cell line to investigate the molecular mechanism by which Sirt1 overexpression modulates leptin signalling. RESULTS: Conditional Sirt1 overexpression in mouse POMC or AgRP neurons prevented age-associated weight gain; overexpression in POMC neurons stimulated energy expenditure via increased sympathetic activity in adipose tissue, whereas overexpression in AgRP neurons suppressed food intake. SIRT1 improved leptin sensitivity in hypothalamic neurons in vitro and in vivo by downregulating protein-tyrosine phosphatase 1B, T cell protein-tyrosine phosphatase and suppressor of cytokine signalling 3. However, these phenotypes were absent in mice consuming a high-fat, high-sucrose diet due to decreases in ARC SIRT1 protein and hypothalamic NAD(+) levels. CONCLUSIONS/INTERPRETATION: ARC SIRT1 is a negative regulator of energy balance, and decline in ARC SIRT1 function contributes to disruption of energy homeostasis by ageing and diet-induced obesity.
Assuntos
Hipotálamo/metabolismo , Leptina/farmacologia , Sirtuína 1/metabolismo , Aumento de Peso/fisiologia , Animais , Calorimetria Indireta , Genótipo , Hipotálamo/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase , Sirtuína 1/genética , Aumento de Peso/genéticaRESUMO
The present study seeks to evaluate the sedative and anxiolytic effects of the 70% ethanol extract of Sinomeni Caulis et Rhizoma (SR). The extract was orally administered to mice at dosages of 25, 50, 100, 200 or 400 mg/kg. The mice were then subjected to an array of behavioral tests to assess the sedative (open-field, rota-rod, and thiopental sodium-induced sleeping test) and anxiolytic (elevated plus maze test) effects of the substance. SR (100, 200 mg/kg) significantly reduced locomotor activity, decreased rota-rod performance, and potentiated thiopental sodium-induced sleeping in mice, all indicative of its sedative effects. SR (50, 100 mg/kg) also produced anxiolytic effects, as shown by an increase in entries and staying time on the open arm of the plus maze. SR's sedative and anxiolytic effects were comparable to that of the benzodiazepine, diazepam. Moreover, to identify SR's probable mechanism of action, intracellular Clâ» ion influx was observed in cultured human neuroblastoma cells. SR dose-dependently increased Clâ» influx, which was blocked by co-administration of the GABAA receptor competitive antagonist, bicuculline. Among the major constituents of SR, only magnoflorine showed a similar increment in Clâ» influx, which was also blocked by bicuculline. Altogether, the present results suggest that SR has sedative and anxiolytic effects, probably mediated by magnoflorine through a GABAergic mechanism of action.
Assuntos
Ansiolíticos/farmacologia , Aporfinas/farmacologia , Hipnóticos e Sedativos/farmacologia , Sinomenium/química , Animais , Ansiolíticos/química , Aporfinas/química , Linhagem Celular Tumoral , Cloretos/análise , Diazepam/farmacologia , Humanos , Hipnóticos e Sedativos/química , Masculino , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologiaRESUMO
Recent studies have revealed that insulin signaling in pancreatic ß-cells and the hypothalamus is critical for maintaining nutrient and energy homeostasis, the failure of which are hallmarks of metabolic syndrome. We previously reported that forkhead transcription factor forkhead box-containing protein of the O subfamily (FoxO)1, a downstream effector of insulin signaling, plays important roles in ß-cells and the hypothalamus when we investigated the roles of FoxO1 independently in the pancreas and hypothalamus. However, because metabolic syndrome is caused by the combined disorders in hypothalamus and pancreas, to elucidate the combined implications of FoxO1 in these organs, we generated constitutively active FoxO1 knockin (KI) mice with specific activation in both the hypothalamus and pancreas. The KI mice developed obesity, insulin resistance, glucose intolerance, and hypertriglyceridemia due to increased food intake, decreased energy expenditure, and impaired insulin secretion, which characterize metabolic syndrome. The KI mice also had increased hypothalamic Agouti-related protein and neuropeptide Y levels and decreased uncoupling protein 1 and peroxisome proliferator-activated receptor γ coactivator 1α levels in adipose tissue and skeletal muscle. Impaired insulin secretion was associated with decreased expression of pancreatic and duodenum homeobox 1 (Pdx1), muscyloaponeurotic fibrosarcoma oncogene homolog A (MafA), and neurogenic differentiation 1 (NeuroD) in islets, although ß-cell mass was paradoxically increased in KI mice. Based on these results, we propose that uncontrolled FoxO1 activation in the hypothalamus and pancreas accounts for the development of obesity and glucose intolerance, hallmarks of metabolic syndrome.
Assuntos
Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica/fisiologia , Intolerância à Glucose/metabolismo , Hipotálamo/metabolismo , Obesidade/metabolismo , Pâncreas/metabolismo , Animais , Proliferação de Células , Ingestão de Alimentos , Metabolismo Energético/genética , Metabolismo Energético/fisiologia , Proteína Forkhead Box O1 , Fatores de Transcrição Forkhead/genética , Intolerância à Glucose/genética , Insulina/metabolismo , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/fisiologia , Camundongos , Obesidade/genética , Consumo de Oxigênio , Fatores de TempoRESUMO
We screened the major bioactive flavones isolated from Scutellaria baicalensis (baicalin, baicalein and oroxylin A) for their convulsion related activities. In electrogenic response score system and the pentylenetetrazole seizure model, baicalein but not oroxylin A and baicalin exhibited anticonvulsant effects. In vitro studies also revealed that baicalein induced intracellular Cl(-) influx, whereas oroxylin A blocked muscimol- and baicalein-induced intracellular Cl(-) influx. The anticonvulsant effect of baicalein was inhibited by flumazenil, a benzodiazepine(BZD) receptor antagonist. Therefore, anticonvulsive effect of baicalein was mediated by the BZD binding site of GABA(A) receptor. The 5, 7-dihydroxyl group is present in the structure of the three flavones. It is postulated that this group played a key role in inducing convulsion-related activities.
Assuntos
Anticonvulsivantes/química , Anticonvulsivantes/farmacologia , Flavonas/química , Flavonas/farmacologia , Hidróxidos/química , Scutellaria baicalensis/química , Convulsões/tratamento farmacológico , Animais , Anticonvulsivantes/uso terapêutico , Cloretos/metabolismo , Avaliação Pré-Clínica de Medicamentos , Eletrochoque , Flavonas/uso terapêutico , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Pentilenotetrazol/farmacologia , Ratos , Ratos Sprague-Dawley , Convulsões/induzido quimicamente , Convulsões/patologia , Convulsões/fisiopatologia , Relação Estrutura-Atividade , Estricnina/farmacologiaRESUMO
The flowers of Carthamus tinctorius L. (Compositae) have been widely used for enhancing blood circulation and postmenopausal disorder in women. In the present study, the potential protective effects of C. tinctorius flower extract (CFE) against reactive oxygen species (ROS) induced osteoblast dysfunction were investigated using osteoblastic MC3T3-E1 cells. The osteoblast function was assessed by measuring alkaline phosphatase activity, collagen content, calcium deposition, and RANKL production, and the oxidative status was assessed by measuring intracellular lipid peroxidation, and protein oxidation in osteoblastic MC3T3-E1 cells. A significant reduction in the alkaline phosphatase activity, collagen, and calcium deposition and an increase in the production of receptor activator of nuclear factor-kB ligand (RANKL) were observed after 0.3 mM H(2)O(2) addition. The H(2)O(2)-induced alterations were prevented by pre-incubating the osteoblasts with 2-10 microg/ml CFE for 48 h. When the oxidative stress was induced by H(2)O(2), the increased production of protein carbonyl and malondialdehyde was also reduced at the same CFE concentration. These results demonstrate that C. tinctorius flower can act as a biological antioxidant in a cell culture experimental model and protect osteoblasts from oxidative stress-induced toxicity.
Assuntos
Antioxidantes/farmacologia , Carthamus tinctorius/química , Peróxido de Hidrogênio/efeitos adversos , Osteoblastos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Colágeno/metabolismo , Flores/química , Peroxidação de Lipídeos , Camundongos , Ligante RANK/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
The aim of the present study was to evaluate the protective effect of palmatine, one of active ingredients of Coptidis rhizoma, against myocardial ischemia-reperfusion (I/R) injury is due to its antioxidant and anti-inflammatory action. Adult male rats were subjected to 30 min of ischemia and 6 or 24h of reperfusion. Rats were randomized to receive vehicle or palmatine 1h before reperfusion. Infarct size, myocardial function, and the antioxidant enzyme activity, such as malonaldehyde (MDA), lactate dehydrogenase (LDH), creatine phosphokinase (CK), superoxide dismutase (SOD) and catalase (CAT) were measured. Palmatine significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (+/-dp/dt) of left ventricular pressure and decreased infarct size by 50% (P<0.01 versus vehicle). As expected, palmatine markedly inhibited the increase of LDH, CK, and MDA contents in I/R rat serum, and it also significantly inhibited the decline of the activity of SOD and CAT in I/R cardiac tissues. In addition, COX-2 and iNOS expression in I/R myocardium was significantly reduced. Interestingly, palmatine increased heme oxygenase (HO)-1 induction in human aortic endothelial cells. We concluded that palmatine protects hearts from I/R injury in rats possibly by reducing oxidative stress and modulating inflammatory mediators.
Assuntos
Alcaloides de Berberina/farmacologia , Cardiotônicos , Medicamentos de Ervas Chinesas/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Antioxidantes/farmacologia , Alcaloides de Berberina/isolamento & purificação , Western Blotting , Coptis chinensis , Creatina Quinase/metabolismo , Medicamentos de Ervas Chinesas/química , Hemodinâmica/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Masculino , Malondialdeído/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/patologia , Ratos , Ratos Sprague-DawleyRESUMO
The rhizome of Atractylodes japonica Koidz. has been used traditionally for the treatment of water retention in the body and is known to have estrogen-like activity. In the present study, the protective effects of A. japonica root extract on the response of osteoblasts to oxidative stress were evaluated. Osteoblastic MC3T3-E1 cells were incubated with hydrogen peroxide and/or A. japonica root extract, and markers of osteoblast function and oxidative damage were examined. A. japonica root extract significantly (p < 0.05) increased cell survival, alkaline phosphatase activity, collagen and calcium deposition and decreased the production of receptor activator of nuclear factor-kB ligand (RANKL), protein carbonyl and malondialdehyde of osteoblastic MC3T3-E1 cells in the presence of hydrogen peroxide. These results demonstrate that A. japonica root can protect the cells from oxidative stress-induced toxicity and may have positive effects on skeletal structure.
Assuntos
Atractylodes/química , Diferenciação Celular/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Osteoblastos/efeitos dos fármacos , Estresse Oxidativo , Extratos Vegetais/farmacologia , Fosfatase Alcalina/metabolismo , Animais , Cálcio/metabolismo , Linhagem Celular , Peroxidação de Lipídeos , Camundongos , Raízes de Plantas/química , Ligante RANK/metabolismoRESUMO
Genetic modification of hematopoietic stem cells holds great promise in the treatment of hematopoietic disorders. However, clinical application of gene delivery has been limited, in part, by low gene transfer efficiency. To overcome this problem, we investigated the effect of retronectin (RN) on lentiviral-mediated gene delivery into hematopoietic progenitor cells (HPCs) derived from bone marrow both in vitro and in vivo. RN has been shown to enhance transduction by promoting colocalization of lentivirus and target cells. We found that RN enhanced lentiviral transfer of the VENUS transgene into cultured c-Kit(+) Lin(-) HPCs. As a complementary approach, in vivo gene delivery was performed by subjecting mice to intra-bone marrow injection of lentivirus or a mixture of RN and lentivirus. We found that co-injection with RN increased the number of VENUS-expressing c-Kit(+) Lin(-) HPCs in bone marrow by 2-fold. Further analysis of VENUS expression in colony-forming cells from the bone marrow of these animals revealed that RN increased gene delivery among these cells by 4-fold. In conclusion, RN is effective in enhancing lentivirus-mediated gene delivery into HPCs.
Assuntos
Fibronectinas/farmacologia , Técnicas de Transferência de Genes , Células-Tronco Hematopoéticas/efeitos dos fármacos , Lentivirus/genética , Proteínas Recombinantes/farmacologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Fibronectinas/química , Células-Tronco Hematopoéticas/metabolismo , Humanos , Lentivirus/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco Multipotentes/efeitos dos fármacos , Células-Tronco Multipotentes/metabolismo , Fragmentos de Peptídeos/farmacologia , Estrutura Terciária de Proteína , Regulação para CimaRESUMO
In this study we investigated the effects of constituents of Amomum xanthioides (AX) on gastritis in rats and on the growth of human gastric cancer cells. The ethanol extract of Amomum xanthioides significantly inhibited HCl ethanol-induced gastric lesions and the growth of Helicobacter pylori (H. pylon). The ethanol extract of AX was further fractionated with hexane, chloroform, butanol and H20. Among these fractions, oral treatment with the butanol fraction at a dose of 350 mg/kg was the most effective at preventing HCl* ethanol-induced gastric lesions. In pylorus ligated rats, the butanol fraction also decreased the volume of gastric secretion and gastric acid output. We isolated six subfractions of the butanol fraction using open column chromatography. Subfraction 4 (150 mg/kg) significantly inhibited HCl* ethanol-induced gastric lesions and gastric secretion in pylorus ligated rats. Using GC-MS we identified the constituents of subfraction 4 to be five aliphatic compounds, 1-hexadecene, 1-nonadecene, cycloeicosane, 1-octadecene and cyclotetracosane. In addition, subfraction 4 reduced cell viability in a dose-dependent manner in human gastric cancer cells (AGS, KATOIII and SNU638). It also increased intracellular Ca2+ concentration in SNU638 cells, an effect that was significantly inhibited by dantrolene, a Ca2+ release blocker. Moreover, dantrolene significantly inhibited subfraction 4-induced cytotoxicity. Taken together, these results suggest that subfraction 4 of the butanol extract of AX has an anti-gastritic effect in rats and is cytotoxic to human gastric cancer cells. The mechanism of its anti-gastritic action may be associated with the inhibition of secretion of gastric acid and anti-H. pylori action. Its cytotoxicity against human gastric cancer cells may be, at least in part, mediated by intracellular Ca2+ dyshomeostasis. From these results, we suggest that AX may be useful for the treatment of gastritis and gastric cancer.
Assuntos
Amomum/química , Gastrite/tratamento farmacológico , Fitoterapia , Extratos Vegetais/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Helicobacter pylori/efeitos dos fármacos , Masculino , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-DawleyRESUMO
Asiatic acid (AA) is a pentacyclic triterpene found in Centella asiatica. In the present study, the mechanism of anticancer effect of AA on skin cancer was investigated. AA decreased viability and induced apoptosis in human melanoma SK-MEL-2 cells in a time- and dose-dependent manner. AA also markedly increased intracellular reactive oxygen species (ROS) level and enhanced the expression of Bax but not Bcl-2 protein in the cells. In addition, AA-induced activation of caspase-3 activity in a dose-dependent manner. Pretreatment with Trolox, an antioxidant, significantly blocked the induction of Bax and activation of caspase-3 in AA-treated cells. Furthermore, Ac-DEVD-CHO, a specific caspase-3 inhibitor, and Trolox prevented the AA-induced apoptosis. AA did not elevate p53 nuclear protein levels that are present in a mutant form in SK-MEL-2 cells. These results suggest that AA-induced apoptosis may be mediated through generation of ROS, alteration of Bax/Bcl-2 ratio and activation of caspase-3, but p53-independent. These results further suggest that AA may be a good candidate for the therapeutic intervention of human skin cancer.