RESUMO
Tanshinone IIA (Tan IIA), a constituent of the traditional medicinal plant Salvia miltiorrhiza BUNGE, has been reported to possess anticancer activity through induction of apoptosis in many cancer cells. Surprisingly, the present study finds that Tan IIA simultaneously causes apoptosis and necroptosis in human hepatocellular carcinoma HepG2 cells. We further find that apoptosis can be converted to necroptosis by pan-caspase inhibitor Z-VAD-fmk, and the two death modes can be blocked by necroptotic inhibitor necrostatin-1. The underlying mechanisms are revealed by analysis of the signaling molecules using western blotting. In control cells, FLICE inhibitory protein in short form (FLIPS) is expressed in relatively high levels and binds to caspase 8 in ripoptosome, which supposedly sustains cell survival. However, in Tan IIA-treated cells, FLIPS is down-regulated and may thus cause homodimer formation of cleaved caspase 8, cleavage of receptor-interacting serine/threonine-protein kinases 1, 3 (RIP1, RIP3), and mixed-lineage kinase domain-like (MLKL), in turn leads to cell apoptosis. In parallel, Tan IIA causes necroptosis by forming a suggested necrosomal complex composed of RIP1/RIP3. Regarding the inhibitors, z-VAD-fmk diminishes the cleaved caspase 8, RIP1, RIP3, and MLKL induced by Tan IIA, and reconstructs the ripoptosome complex, which marks cells moving from apoptosis to necroptosis. Nec-1 recovers the Tan IIA down-regulated FLIPS, consequently causes FLIPS to form heterodimer with caspase 8 and thus block apoptosis. Meanwhile, cleaved forms of RIP1 and RIP3 were observed preventing necroptosis. Intriguingly, the cytotoxicity of tumor necrosis factor-related apoptosis-inducing ligand to HepG2 cells is enhanced by Tan IIA in a pilot study, which may be attributed to low FLIPS levels induced by Tan IIA. In short, Tan IIA simultaneously induces both Nec-1 inhibition and FLIPS regulation-mediated apoptosis/necroptosis, which has not been previously documented. Moreover, the involvement of the cleavage type of MLKL in executing necroptosis warrants further investigation.
RESUMO
Acidic fibroblast growth factor (aFGF) is a neurotrophic factor which is a powerful neuroprotective and neuroregenerative factor of the nervous system. Prior study had shown that levels of FGFs significantly increase following ischemic injury, reflecting a physiological protection mechanism. However, few reports demonstrated the efficacy of applying aFGF in cerebral ischemia. A recent report showed that the intranasal aFGF treatment improved neurological functional recovery; however, it did not significantly reduce the lesion size in ischemic rats. The present study examines the neuroprotective effect of aFGF on cortical neuron-glial cultures under oxygen glucose deprivation (OGD)-induced cell damage and investigates whether epidural application of slow-released aFGF could improve benefit on ischemic stroke injury in conscious rats. We used a topical application of aFGF mixed in fibrin glue, a slow-release carrier, over the peri-ischemic cortex and examined such treatment on cerebral infarction and behavioral impairments of rats subjected to focal cerebral ischemia (FCI). Results demonstrate that aFGF effectively protected cortical neuron-glial cultures from OGD-induced neuronal damage. Neurite extension from cortical neurons was significantly enhanced by aFGF, mediated through activation of AKT and ERK. In addition, topical application of fibrin glue-mixed aFGF dose-dependently reduced ischemia-induced brain infarction and improved functional restoration in ischemic stroke rats. Slow-released aFGF not only protected hippocampal and cortical cell loss but reduced microglial infiltration in FCI rats. Our results suggest that aFGF mixed in fibrin glue could prolong the protective/regenerative efficacy of aFGF to the damaged brain tissue and thus improve the functional restorative effect of aFGF.
Assuntos
Fator 1 de Crescimento de Fibroblastos/uso terapêutico , Infarto da Artéria Cerebral Média/patologia , Neuritos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/uso terapêutico , Animais , Infarto Encefálico/induzido quimicamente , Infarto Encefálico/tratamento farmacológico , Hipóxia Celular/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Embrião de Mamíferos , Fator 1 de Crescimento de Fibroblastos/farmacologia , Lateralidade Funcional , Glucose/deficiência , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/tratamento farmacológico , MAP Quinase Quinase Quinase 3/metabolismo , Masculino , Transtornos dos Movimentos/tratamento farmacológico , Transtornos dos Movimentos/etiologia , Neuroglia/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
PURPOSE: To evaluate low dose-rate radiation effects on the physical heights of children staying in apartments with 60Co-contaminated steel construction. MATERIALS AND METHODS: Children who once resided in radiocontaminated apartments since early 1983 were examined for height and body weight status from age 1 month to 18 years and before they moved out of the apartments. The physical heights and body weights of 21 898 age- and sex-matched non-exposed children from a nationwide school surveillance in 1997-98 were taken as controls. The physical height data were shown as height percentiles (HP) compared with reference children and age-specific relative height differences (RHD). RESULTS: HP and RHD in 48 exposed boys and 37 girls were analysed using generalized estimating equations (GEE), which accounted for multiple measurements and correlation between these measurements in the same individuals during this period. After adjusting for effects from parental heights and body mass index (BMI), clear dose-related decreases in HP and RHD were observed in the exposed boys with a cumulative exposure > 60 mSv. CONCLUSIONS: Prolonged low dose-rate y-radiation exposure was associated with adverse effects on the physical heights of growing boys, but were less apparent in the exposed girls.
Assuntos
Estatura/efeitos da radiação , Raios gama/efeitos adversos , Adolescente , Fatores Etários , Estudos de Casos e Controles , Criança , Pré-Escolar , Radioisótopos de Cobalto/efeitos adversos , Estudos de Coortes , Relação Dose-Resposta à Radiação , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Modelos Estatísticos , Estudos Retrospectivos , Fatores Sexuais , Fatores de TempoRESUMO
BACKGROUND: Early treatment for the neonate with pulmonary atresia and intact ventricular septum (PA-IVS) is important if a high mortality rate is to be avoided. The treatment includes prostaglandin administration, balloon atrial septostomy, pulmonary valvotomy, a shunting procedure and patch repair for the right ventricular outflow tract (RVOT). This study discusses the early treatment and risk factors of this disease that are essential for assessing the risk of surgery and predicting outcome. METHODS: The medical records, echocardiograms, catheterization data and cineangiograms of 29 patients with PA-IVS diagnosed at our institution from 1987 to 1997 were reviewed retrospectively. Clinical manifestations including age, body weight, sex ratio, type of surgery and outcome were analyzed. RESULTS: Three of four patients with a right ventricular volume of less than 1 ml died, and all patients with a right ventricular volume of greater than 2 ml survived. Four of six patients with a tricuspid valvular area of between 0.25 and 0.5 cm2 died, but patients with an area of greater than 0.5 cm2 survived. One case with a monopartite right ventricle died. Patients with a bipartite or tripartite right ventricle had higher survival rates than those with a monopartite right ventricle. Patients with a the right ventricle dependent coronary sinusoid had a higher risk for mortality, even after surgery, than those with normal coronary circulation. CONCLUSIONS: A small right ventricular volume, the presence of a coronary sinusoid involving the right ventricle, a short linear length of the tricuspid valve and a small area of the tricuspid valve were the risk factors associated with a negative outcome in neonates with PA-IVS.
Assuntos
Atresia Pulmonar/cirurgia , Feminino , Septos Cardíacos , Ventrículos do Coração , Humanos , Lactente , Recém-Nascido , Masculino , Estudos RetrospectivosRESUMO
This is the first report to describe and characterize a cell-free protein synthesis system derived from kidney tissue. The optimum conditions for [3H]-valine incorporation into protein by the post-mitochondrial supernatant from whole kidneys were found to be: pH 6.9, 7.5 mM MgCl2, 150 mM KCl, 10 mM ATP, and 2 mM GTP. The cell-free protein-synthetising activities of kidneys isolated from 4.5-, 7.5-, 22-, and 31-month-old female Fischer F344 rats were measured using the post-mitochondrial supernatant. A 73-87% decrease in cell-free protein synthesis was observed between 4.5 and 31 months of age. Both the cell sap and microsomal fractions of the kidney post-mitochondrial supernatant from old rats were less active in protein synthesis than these fractions from the kidneys of young rats. No age-related change in the activity of RNAase in the kidney post-mitochondrial supernatant was observed. Kidney ribosomes stripped of endogenous mRNA were found to be active in poly(uridylic acid)-directed polyphenylalanine synthesis. The effect of aging on the fidelity of translation was determined by measuring poly(uridylic acid)-directed [14C]-phenylalanine and [3H]leucine incorporation by kidney ribosomes isolated from rats of various ages. No age-related change in the fidelity of poly(uridylic acid) translation by kidney ribosomes was observed.