Bo Li
共找到 4 条论著文献

1、Effect of long period stacking ordered structure on mechanical and damping properties of as-cast Mg-Zn-Y-Zr alloy

摘要:The effect of long-period stacking ordered (LPSO) structure on mechanical and damping properties of as-cast Mg-Zn-Y-Zr alloy were investigated. Obtained results indicate that the Mg-x%Zn-2x%Y-0.6%Zr alloys are mainly comprised of α-Mg and LPSO phase. The grain sizes of the Mg-Zn-Y-Zr alloys are obviously refined and the mechanical properties are improved continuously with the formation of LPSO phase, with a maximum value of 222.5 MPa in ultimate tensile strength and 18.9% in elongation. The fracture mechanism of alloys transforms from cleavage fracture to quasi-cleavage fracture with increasing amount of LPSO phase. The damping capacities of Mg-Zn-Y-Zr alloys increase continuously with the increasing LPSO phase and the damping behavior can be explained by the moving model of Shockley partial dislocation. Due to the stacking fault probability, the LPSO phase in the Mg-Zn-Y-Zr alloys could be new damping source to dissipate energy so as to contribute to the improvement of damping capacities.
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2、Nitidine chloride inhibits proliferation, induces apoptosis via the Akt pathway and exhibits a synergistic effect with doxorubicin in ovarian cancer cell

摘要:Nitidine chloride (NC) exhibits anti-tumor properties in various types of tumor. However, to the best of our knowledge there is no previous evidence of NC involvement in the apoptosis or proliferation of ovarian cancer cells and the underlying molecular mechanisms. The present study aimed to investigate the influence of NC on the viability and apoptosis of ovarian cancer cells and the synergistic effect NC and doxorubicin (DOX) may have on ovarian cancer cells. The viability and proliferation of ovarian cancer cells were examined using a methyl thiazolyl tetrazolium assay and 3H-thymidine incorporation assay. The apoptotic rate of ovarian cancer cells was detected by flow cytometry. The expression of apoptosis???associated proteins and Akt serine/threonine kinase??1 (Akt) were determined by western blot analysis following NC treatment. The inhibitory effect of NC on the proliferation of ovarian cancer cells was demonstrated in a time and dose???dependent manner. The pro-apoptotic effect of NC on ovarian cancer cells was also observed. It was determined that NC significantly downregulated the protein expression levels of B???cell CLL/lymphoma 2 (Bcl-2) and upregulated the expression of Bcl???2???associated X protein, p53, caspase???3 and ???9. NC suppressed Akt phosphorylation. Additionally, the present study demonstrated that the effect of NC on the proliferation and apoptosis of ovarian cancer cells was Akt???dependent by using the phosphatidylinositol-4,5-bisphosphate??3-kinase/Akt signaling pathway inhibitor, LY294002. NC exhibited a synergistic inhibitory effect on the viability of ovarian cancer cells when combined with DOX. The current study demonstrated that NC inhibited the proliferation and induced the apoptosis of ovarian cancer cells via the Akt signaling pathway and highlighted its potential clinical application for the treatment of ovarian cancer.
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3、AKT-mediated phosphorylation of ATG4B impairs mitochondrial activity and enhances the Warburg effect in hepatocellular carcinoma cell 2018

摘要:1 online resource ABSTRACT: Phosphorylation is a major type of post-translational modification, which can influence the cellular physiological function. ATG4B, a key macroautophagy/autophagy-related protein, has a potential effect on the survival of tumor cells. However, the role of ATG4B phosphorylation in cancers is still unknown. In this study, we identified a novel phosphorylation site at Ser34 of ATG4B induced by AKT in HCC cells. The phosphorylation of ATG4B at Ser34 had little effect on autophagic flux, but promoted the Warburg effect including the increase of L-lactate production and glucose consumption, and the decrease of oxygen consumption in HCC cells. The Ser34 phosphorylation of ATG4B also contributed to the impairment of mitochondrial activity including the inhibition of F1 Fo-ATP synthase activity and the elevation of mitochondrial ROS in HCC cells. Moreover, the phosphorylation of ATG4B at Ser34 enhanced its mitochondrial location and the subsequent colocalization with F1 Fo-ATP synthase in HCC cells. Furthermore, recombinant human ATG4B protein suppressed the activity of F1 Fo-ATP synthase in MgATP submitochondrial particles from patient-derived HCC tissues in vitro. In brief, our results demonstrate for the first time that the phosphorylation of ATG4B at Ser34 participates in the metabolic reprogramming of HCC cells via repressing mitochondrial function, which possibly results from the Ser34 phosphorylation-induced mitochondrial enrichment of ATG4B and the subsequent inhibition of F1 Fo-ATP synthase activity. Our findings reveal a noncanonical working pattern of ATG4B under pathological conditions, which may provide a scientific basis for developing novel strategies for HCC treatment by targeting ATG4B and its Ser34 phosphorylation.
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4、Evaluation of nigrostriatal damage and its change over weeks in a rat model of Parkinson's disease: small animal positron emission tomography studies with [11C]β-CFT

摘要:Introduction: The cardinal pathological feature of Parkinson's disease (PD) is progressive loss of dopaminergic neurons. Since dopamine transporter (DAT) is a protein located presynaptically on dopaminergic nerve terminals, radioligands that bind to these sites are promising radiopharmaceuticals for evaluation of the integrity of the dopamine system. This study using positron emission tomography (PET) tracers, [11C]-2β-carbomethoxy-3β-(4-fluorophenyl)-tropane ([11C]β-CFT, radioligand for DAT), was aimed at evaluating the degree of nigrostriatal damage and its change over weeks in a rat model of PD.Methods: The brains of these rats were unilaterally lesioned by mechanical transection of the nigrostriatal dopamine pathway at the medial forebrain bundle (MFB). Behavioral studies were carried out by apomorphine (APO) challenge prior to and 1, 2 and 4 weeks after MFB axotomy. Small animal PET scans were performed 2 days after the behavioral test. Immunohistochemistry was conducted 4 days after the last PET scan.Results: Compared with the contralateral intact side, a progressively decreased [11C]β-CFT binding was observed on the lesioned side which correlated inversely with the APO-induced rotations. Postmortem immunohistochemical studies confirmed the loss of both striatal dopamine fibers and nigral neurons on the lesioned side.Conclusion: These findings not only demonstrate that the neuronal degeneration in this model is relatively slow, but also suggest [11C]β-CFT is a sensitive marker to monitor the degree of nigrostriatal damage and its change over weeks. This marker can be used prospectively to study the progression of the disease, thereby making detection of early phases of PD possible.
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