RESUMO
Soil contamination with arsenic (As) can cause phytotoxicity and reduce crop yield. The mechanisms of As toxicity and tolerance are not fully understood. In this study, we used a forward genetics approach to isolate a rice mutant, ahs1, that exhibits hypersensitivity to both arsenate and arsenite. Through genomic resequencing and complementation tests, we identified OsLPD1 as the causal gene, which encodes a putative lipoamide dehydrogenase. OsLPD1 was expressed in the outer cell layer of roots, root meristem cells, and in the mesophyll and vascular tissues of leaves. Subcellular localization and immunoblot analysis demonstrated that OsLPD1 is localized in the stroma of plastids. In vitro assays showed that OsLPD1 exhibited lipoamide dehydrogenase (LPD) activity, which was strongly inhibited by arsenite, but not by arsenate. The ahs1 and OsLPD1 knockout mutants exhibited significantly reduced NADH/NAD+ and GSH/GSSG ratios, along with increased levels of reactive oxygen species and greater oxidative stress in the roots compared with wild-type (WT) plants under As treatment. Additionally, loss-of-function of OsLPD1 also resulted in decreased fatty acid concentrations in rice grain. Taken together, our finding reveals that OsLPD1 plays an important role for maintaining redox homeostasis, conferring tolerance to arsenic stress, and regulating fatty acid biosynthesis in rice.
Assuntos
Arsênio , Di-Hidrolipoamida Desidrogenase , Ácidos Graxos , Homeostase , Oryza , Proteínas de Plantas , Estresse Fisiológico , Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/genética , Arsênio/toxicidade , Arsenitos/toxicidade , Di-Hidrolipoamida Desidrogenase/metabolismo , Di-Hidrolipoamida Desidrogenase/genética , Ácidos Graxos/biossíntese , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mutação/genética , Oryza/genética , Oryza/efeitos dos fármacos , Oryza/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plastídeos/metabolismo , Plastídeos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genéticaRESUMO
OBJECTIVE: Over the past decade, heat shock protein 90 (HSP90) inhibitors have emerged as promising anticancer drugs in solid and hematological malignancies. Flavokawain C (FKC) is a naturally occurring chalcone that has been found to exert considerable anti-tumor efficacy by targeting multiple molecular pathways. However, the efficacy of FKC has not been studied in nasopharyngeal carcinoma (NPC). Metabolic abnormalities and uncontrolled angiogenesis are two important features of malignant tumors, and the occurrence of these two events may involve the regulation of HSP90B1. Therefore, this study aimed to explore the effects of FKC on NPC proliferation, glycolysis, and angiogenesis by regulating HSP90B1 and the underlying molecular regulatory mechanisms. METHODS: HSP90B1 expression was analyzed in NPC tissues and its relationship with patient's prognosis was further identified. Afterward, the effects of HSP90B1 on proliferation, apoptosis, glycolysis, and angiogenesis in NPC were studied by loss-of-function assays. Next, the interaction of FKC, HSP90B1, and epidermal growth factor receptor (EGFR) was evaluated. Then, in vitro experiments were designed to analyze the effect of FKC treatment on NPC cells. Finally, in vivo experiments were allowed to investigate whether FKC treatment regulates proliferation, glycolysis, and angiogenesis of NPC cells by HSP90B1/EGFR pathway. RESULTS: HSP90B1 was highly expressed in NPC tissues and was identified as a poor prognostic factor in NPC. At the same time, knockdown of HSP90B1 can inhibit the proliferation of NPC cells, trigger apoptosis, and reduce glycolysis and angiogenesis. Mechanistically, FKC affects downstream EGFR phosphorylation by regulating HSP90B1, thereby regulating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway. FKC treatment inhibited the proliferation, glycolysis, and angiogenesis of NPC cells, which was reversed by introducing overexpression of HSP90B1. In addition, FKC can affect NPC tumor growth and metastasis in vivo by regulating the HSP90B1/EGFR pathway. CONCLUSION: Collectively, FKC inhibits glucose metabolism and tumor angiogenesis in NPC by targeting the HSP90B1/EGFR/PI3K/Akt/mTOR signaling axis.
RESUMO
Glioblastoma is the most fatal and insidious malignancy, due to the existence of the blood-brain barrier (BBB) and the high invasiveness of tumor cells. Abnormal mitochondrial viscosity has been identified as a key feature of malignancies. Therefore, this study reports on a novel fluorescent probe for mitochondrial viscosity, called ZVGQ, which is based on the twisted intramolecular charge transfer (TICT) effect. The probe uses 3-dicyanomethyl-1,5,5-trimethylcyclohexene as an electron donor moiety and molecular rotor, and triphenylphosphine (TPP) cation as an electron acceptor and mitochondrial targeting group. ZVGQ is highly selective, pH and time stable, and exhibits rapid viscosity responsiveness. In vitro experiments showed that ZVGQ could rapidly recognize to detect the changes in mitochondrial viscosity induced by nystatin and rotenone in U87MG cells and enable long-term imaging for up to 12 h in live U87MG cells. Additionally, in vitro 3D tumor spheres and in vivo orthotopic tumor-bearing models demonstrated that the probe ZVGQ exhibited exceptional tissue penetration depth and the ability to penetrate the BBB. The probe ZVGQ not only successfully visualizes abnormal mitochondrial viscosity changes, but also provides a practical and feasible tool for real-time imaging and clinical diagnosis of glioblastoma.
Assuntos
Corantes Fluorescentes , Glioblastoma , Mitocôndrias , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Humanos , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Mitocôndrias/metabolismo , Viscosidade , Linhagem Celular Tumoral , Animais , Camundongos , Camundongos Nus , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Imagem ÓpticaRESUMO
The study aimed to achieve enhanced targeted cytotoxicity and cell-internalization of cisplatin-loaded deoxyribonucleic acid-nanothread (CPT-DNA-NT),mediated by scavenger receptors into HeLa cells.DNA-NT was developed with stiff-topology utilizing circular-scaffold to encapsulate CPT.Atomic force microscopy (AFM) characterization of the DNA-NT showed uniformity in the structure with a diameter of 50-150 nm and length of 300-600 nm.The successful fabrication of the DNA-NT was confirmed through native-polyacrylamide gel electrophoresis analysis,as large the molecular-weight (polymeric) DNA-NT did not split into constituting strands under applied current and voltage.The results of cell viability confirmed that blank DNA-NT had the least cytotoxicity at the highest concentration (512 nM) with a viability of 92% as evidence of its biocompatibility for drug delivery.MTT assay showed superior cyto-toxicity of CPT-DNA-NT than that of the free CPT due to the depot release of CPT after DNA-NT inter-nalization.The DNA-NT exhibited targeted cell internalizations with the controlled intracellular release of CPT (from DNA-NT),as illustrated in confocal images.Therefore,in vitro cytotoxicity assessment through flow cytometry showed enhanced apoptosis (72.7%) with CPT-DNA-NT (compared to free CPT;64.4%).CPT-DNA-NT,being poly-anionic,showed enhanced endocytosis via scavenger receptors.
RESUMO
<p><b>Background</b>Dendritic cells (DCs) play an important role in host defense against pathogen infection. DC-specific intercellular adhesion molecule-3-grabbing nonintegrin (SIGN) is a group II C-type lectin receptor and specifically expressed on the surface of DCs. This study aimed to determine whether DC-SIGN affects intracellular signaling activation, Th1/Th2 imbalance and aspergillus immune evasion in aspergillus infection, and explore the application of DC-SIGN-modified DCs in immunotherapy.</p><p><b>Methods</b>DCs were first obtained from the mononuclear cells of peripheral blood. The interferon (IFN)-γ and dexamethasone (Dex) were used to stimulate DCs. The expression of DC-SIGN, Th1 and Th2 cytokines, and the capacity of DCs in stimulating T cells proliferation and phagocytosis, and nuclear factor (NF)-κB activation were analyzed. In addition, adenovirus expression vector Ad-DC-SIGN was generated to transfect DCs. Mannan was used to block DC-SIGN signaling for confirming the involvement of DC-SIGN function in Aspergillus fumigatus (Af)-induced DCs maturation. The unpaired, two-tailed Student's t-test was used in the comparisons between two groups.</p><p><b>Results</b>Exogenous IFN-γ could activate Af-induced DCs and promote the Th0 cells toward Th1 profile (interleukin [IL]-12 in IFN-γ/Af group: 50.96 ± 4.38 pg/ml; control/Af group: 29.70 ± 2.00 pg/ml, t = 10.815, P < 0.001). On the other hand, Dex inhibited the secretion of Th2 cytokines (IL-10 in Dex/Af group: 5.27 ± 0.85 pg/ml; control/Af group: 15.14 ± 1.40 pg/ml, t = 14.761, P < 0.001)), and successfully caused immunosuppression. After transfection with Ad-DC-SIGN, DCs have improved phagocytosis (phagocytosis rates in Ad-DC-SIGN group: 74.0% ± 3.4%; control group: 64.7% ± 6.8%, t = 3.104, P = 0.013). There was more Th1 cytokine secreted in the Af-induced DC-SIGN modified DCs (IL-12 in Ad-DC-SIGN/Af group: 471.98 ± 166.31 pg/ml; control/Af group: 33.35 ± 5.98 pg/ml, t = 6.456, P = 0.001), correlated to the enhanced NF-κB activation.</p><p><b>Conclusion</b>Overexpressing DC-SIGN in DCs had a protective function on aspergillosis.</p>
RESUMO
AIM:To explore the effect of acteoside on behavioral changes and endoplasmic reticulum stress(ERS)in prefrontal cortex of depressive rats.METHODS:Sprague-Dawley(SD)rats(n=108)were randomly divided into 6 groups:control group,model group,fluoxetine(20 mg/kg)group,low-dose(30 mg/kg)acteoside group,medium-dose(60 mg/kg)acteoside group and high-dose(120 mg/kg)acteoside group,with 18 rats in each group.The depres-sive-like rat model was established by chronic unpredictable mild stress(CUMS)combined with solitary way for 28 d.The rats in fluoxetine group and acteoside groups were treated with fluoxetine(20 mg/kg)or acteoside(30 mg/kg,60 mg/kg and 120 mg/kg)once daily by intragastric administration for 3 weeks.The rats in control group and model group were both given equal volume of saline by intragastric administration for 3 weeks.The behavioral changes were detected by the open-field test and sugar preference experiment.The protein expression of glucose-regulated protein 78(GRP78 )and C/EBP homologous protein(CHOP)was assessed by immunofluorescence and Western blot.The caspase-3 activity was measured by spectrophotometer.RESULTS:Compared with control group ,the total distance ,time spent in the center and sugar in-take were all decreased ,the expression of GRP78 and CHOP was increased ,and the activity of caspase-3 was increased in model group ,fluoxetine group and acteoside groups(P<0.05 ).Compared with model group ,the total distance ,time spent in the center and sugar intake were increased ,the expression of GRP78 and CHOP was reduced ,and the activity of caspase-3 was decreased(P<0.05)in fluoxetine group and acteoside groups.CONCLUSION:Acteoside improves de-pressive-like behaviors in depressive rats ,which may be related to the inhibition of ERS and neuronal apoptosis in prefron-tal cortex.
RESUMO
Lycopene liposomes were prepared by conventional rotary-evaporated film-ultrasonication method. The release of lycopene from lycopene liposome was evaluated in vitro. The pharmacokinetic parameters of lycopene liposomes (L-LYC) and lycopene (LYC) oil, the effect of LYC and L-LYC on antioxidation were also investigated in rats. HPLC method was used to assay the concentration of lycopene in rat's plasma. Pharmacokinetic parameters were estimated by 3P97 program. The release of L-LYC and LYC were measured in the artificial stomach liquid and bowel liquid. After 4 weeks of L-LYC or LYC feeding, the activity of SOD, T-AOC, GSH-Px, MDA and CAT in serum and liver were measured separately. The pharmacokinetic parameters of LYC oil and L-LYC in a single dose were 4.45 and 7.45 h for Tmax; 0.473 and 0.654 microg x mL(-1) for Cmax; 12.38 and 21.67 mirog x h x mL(-1) for AUC,respectively. The activities of GSH-Px and T-AOC in serum and liver of the L-LYC group increased (P < 0.05) and the concentrations of MDA and CAT decreased significantly (P < 0.05). It could be concluded that lycopene liposomes could prolong the time of absorption. L-LYC could increase antioxidative effect and reduce lipid peroxidation obviously compared with LYC in rats.
Assuntos
Animais , Masculino , Ratos , Administração Oral , Antioxidantes , Farmacocinética , Área Sob a Curva , Carotenoides , Farmacocinética , Catalase , Sangue , Metabolismo , Cromatografia Líquida de Alta Pressão , Métodos , Portadores de Fármacos , Glutationa Peroxidase , Sangue , Metabolismo , Peroxidação de Lipídeos , Lipossomos , Química , Fígado , Metabolismo , Malondialdeído , Sangue , Metabolismo , Distribuição Aleatória , Ratos Sprague-Dawley , Superóxido Dismutase , Sangue , MetabolismoRESUMO
Objective To explore the relationship of c-fos protein and cell apoptosis by observing the expression of c-fos protein in hippocampus of newborn rat with hypoxic-ischemic brain damage(HIBD).Methods Forty-eight 7-day SD neonatal rats were randomly divided into control group(n=6) and experiment group(n=42).The models of HIBD were established in neonatal rats by inhaling the mixed gases of 920 mL/L N2 and 80 mL/L O2,and the animals were sacrificed by dislocation their heads at different time points(0.5,1,3,6,12,24,48,72 h),then the hippocampus were dissected by morphological analysis.Results The apoptotic cells appeared at the time point of 3 h,and reached the peak at 48 h,then decreased.The positive cell of c-fos protein increased from the time point of 30 min and reached the peak at 2 h and then decreased gradually,and there was a contrary tendency between the expression of c-fos protein and the number of damaged brain cells by HIBD(r=-0.57 P
RESUMO
Activation of N-methyl-d-aspartic acid (NMDA) receptor plays an important role in neuronal apoptosis induced by cerebral ischemia but the underlying mechanisms are still unclear. The present study examined the neuroprotection of three chloride blockers in an in vitro cell model of cerebral ischemia established by treatment of cultured rat hippocampal neurons with NMDA. Hoechst 33258 staining and MTT assay were used to detect neuronal apoptosis and cell viability, respectively. The neuroprotective effects of chloride channel blockers on the cell viability and neuronal apoptosis were only observed when the blockers were applied before NMDA exposure. In comparison with DIDS, SITS showed more potent protective effect in a dose-dependent manner, whereas NPPB showed no significant neuroprotective effect. The results demonstrate that pretreatment with both SITS and DIDS have protective effect against neuronal apoptosis, which is achieved by blocking both NMDA receptor and chloride channel.
Assuntos
Animais , Ratos , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico , Farmacologia , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-dissulfônico , Farmacologia , Animais Recém-Nascidos , Apoptose , Bisbenzimidazol , Química , Sobrevivência Celular , Células Cultivadas , Canais de Cloreto , Hipocampo , Biologia Celular , Microscopia de Fluorescência , N-Metilaspartato , Farmacologia , Neurônios , Química , Biologia Celular , Fármacos Neuroprotetores , Farmacologia , Ratos Sprague-DawleyRESUMO
Objective To investigate the impact of alterations within the space of Disse micro- environment on the migration of hepatic stellate cells(HSC) during the process of liver fibrosis,and to ex plore the novel mechanism of liver fibrosis from the view of cell migration.Methods A modified in vitro Boyden chamber system to partially mimic in vivo microenvironment of Disse space of normal and liver fibrosis was employed.The effects of fibrogenetic growth factors on the migration of HSC in liver fibrosis were observed via cell migration and cell proliferation experiments.Results Enhanced platelet-derived growth factor(PDGF)-BB,transforming growth factor(TGF)-?1 and/or epithelial growth factor(EGF) in liver fibrosis resulted in an increase in migratory capacity of activated HSC.The enhanced migration of HSCs induced by PDGF-BB was partially associated with their increased proliferation,while,TGF-?1 or EGF-induced migration was proliferation independent.The elevation of basic fibroblast growth factor (bFGF) or vascular endothelial growth factor(VEGF)during liver fibrosis had no effect on the migration of HSCs.Conclusions The study provides valuable insights into the role of space of Disse microenvironment in regulating HSC migratory behavior.TGF-?1,PDGF-BB and EGF,which increased in liver fibrosis, could induce the migration of activated HSC.However,bFGF or VEGF has no such kind of effect,al- though they also increased during liver fibrosis.
RESUMO
Objective To observe the expression of bcl-2 gene in cell apoptosis of neonatal rats followed by hypoxic-ischemic brain damage(HIBD) and investigate the mechanism of neuronal apoptosis after HIBD.Methods Fifty-four neonatal SD rats were used in 1 sham-operated group and 8 trial groups. The models of HIBD were established in neonatal rats by inhaling the mixed gases of 92 % N 2 and 8 % O 2, the animals were sacrificed by dislocation their heads at different time points(0.5,1,3,6,12,24,48,72 h), the hippocampus were dissected for morphological analysis. The neuronal apoptosis and the expression of bcl-2 gene in hippocampus were detected by the methods of immunohistochemistry. Results The apoptotic cells appeared at the time point of 3 h, and reached the peak at 48 h, then decreased. The positive cell of bcl-2 protein increased from the time point of 30 min and reached the peak at 6 h and then decreased gradually following HIBD. Conclusion The expression of bcl-2 gene plays a role in the process of neuronal apoptosis following HIBD.
RESUMO
Objective To investigate the change of eNOS,the spermatogenic cell proliferation,apoptosis in mouse testis exerted by alcohol. Methods The immunohistochemical staining method for detecting of eNOS,PCNA,TUNEL method for detecting of apoptotic cells and the satistics analysis were used in the present study. Results With the increase of alcohol concentration,the structure of seminiferous tubule changed,the diameter of seminiferous tubule decreased,the surface density of postive eNOS cells increased gradually,and the number of positve PCNA cells and apoptosis cells also increased.There were significant difference in 15% alcohol concentration group compared with the other groups(P