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1.
Background： Edaravone had been validated to effectively protect against ischemic injuries. In this study, we investigated the protective effect of edaravone by observing the effects on anti-apoptosis, regulation of Bcl-2/Bax protein expression and recovering from damage to mitochondria after OGD （oxygen-glucose deprivation）-reperfusion. Methods： Viability of PC 12 cells which were injured at different time of OGD injury, was quantified by measuring MTT （2-（4,5-dimethylthia-zol-2-yl）-2,5-diphenyltetrazolium bromide） staining. In addition, PC 12 cells＇ viability was also quantified after their preincubation in different concentration of edaravone for 30 min followed by （OGD）. Furthermore, apoptotic population of PC 12 cells that reinsulted from OGD-reperfusion with or without preincubation with edaravone was determined by flow cytometer analysis, electron microscope and Hoechst/Pl staining. Finally, change of Bcl-2/Bax protein expression was detected by Western blot. Results： （1） The viability of PC12 cells decreased with time （1-12 h） after OGD. We regarded the model of OGD 2 h, then replacing DMEM （Dulbecco＇s Modified Eagle＇s Medium） for another 24 h as an OGD-reperfusion in this research. Furthermore, most PC 12 cells were in the state of apoptosis after OGD-reperfusion. （2） The viability of PC 12 cells preincubated with edaravone at high concentrations （1, 0.1, 0.01 μmol/L） increased significantly with edaravone protecting PC 12 cells from apoptosis after OGD-reperfusion injury. （3） Furthermore, edaravone attenuates the damage of OGD-reperfusion on mitochondria and regulated Bcl-2/Bax protein imbalance expression after OGD-reperfusion. Conclusion： Neuroprotective effects of edaravone on ischemic or other brain injuries may be partly mediated through inhibition of Bcl-2/Bax apoptotic pathways by recovering from the damage of mitochondria.  相似文献   

2.
Sevoflurane postconditioning reduces myocardial infarct size.The objective of this study was to examine the role of the phosphatidylinositol-3-kinase(PI3K)/Akt pathway in anesthetic postconditioning and to determine whether PI3K/Akt signaling modulates the expression of pro-and antiapoptotic proteins in sevoflurane postconditioning.Isolated and perfused rat hearts were prepared first,and then randomly assigned to the following groups:Sham-operation(Sham),ischemia/reperfusion(Con),sevoflurane postconditioning(SPC),Sham plus 100 nmol/L wortmannin(Sham+Wort),Con+Wort,SPC+Wort,and Con+dimethylsulphoxide(DMSO).Sevoflurane postconditioning was induced by administration of sevoflurane(2.5%,v/v) for 10 min from the onset of reperfusion.Left ventricular developed pressure(LVDP),left ventricular end-diastolic pressure(LVEDP),maximum increase in rate of LVDP(+dP/dt),maximum decrease in rate of LVDP(?dP/dt),heart rate(HR),and coronary flow(CF) were measured at baseline,R30 min(30 min of reperfusion),R60 min,R90 min,and R120 min.Creatine kinase(CK) and lactate dehydrogenase(LDH) were measured after 5 min and 10 min reperfusion.Infarct size was determined by triphenyltetrazolium chloride staining at the end of reperfusion.Total Akt and phosphorylated Akt(phospho-Akt),Bax,Bcl-2,Bad,and phospho-Bad were determined by Western blot analysis.Analysis of variance(ANOVA) and Student-Newman-Keuls' test were used to investigate the significance of differences between groups.The LVDP,±dP/dt,and CF were higher and LVEDP was lower in the SPC group than in the Con group at all points of reperfusion(P0.05).The SPC group had significantly reduced CK and LDH release and decreased infarct size compared with the Con group [(22.9±8)% vs.(42.4±9.4)%,respectively;P0.05].The SPC group also had increased the expression of phospho-Akt,Bcl-2,and phospho-Bad,and decreased the expression of Bax.Wortmannin abolished the cardioprotection of sevoflurane postconditioning.Sevoflurane postconditioning may protect the isolated rat heart.Activation of PI3K and modulation of the expression of pro-and antiapoptotic proteins may play an important role in sevoflurane-induced myocardial protection.  相似文献   

3.
The aim was to investigate how the PI3K/Akt pathway is involved in the protection of dexmedetomidine against propofol. The hippocampal neurons from fetal rats were separated and cultured in a neurobasal medium. Cell viability was assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Then neurons were pretreated with different concentrations of dexmedetomidine before 100 μmol/L propofol was added. Akt, phospho-Akt (p-Akt), Bad, phospho-Bad (p-Bad), and Bcl-xL were detected by Western blot. Also, neurons were pretreated with dexmedetomidine alone or given the inhibitor LY294002 before dexmedetomidine pretreatment, and then propofol was added for 3 h. The results demonstrated that propofol decreased the cell viability and the expression of p-Akt and p-Bad proteins, increased the level of Bad, and reduced the ratio of Bcl-xL/Bad. Dexmedetomidine pretreatment could reverse these effects. The enhancement of p-Akt and p-Bad induced by dexmedetomidine was prevented by LY294002. These results showed that dexmedetomidine potently protected the developing neuron and this protection may be partly mediated by the PI3K/Akt pathway.  相似文献   

4.
Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.  相似文献   

5.
目的：观察开心散含药血清对皮质酮（corticosterone）损伤大鼠大脑皮质星形胶质细胞CTXTNA2的影响。方法：制备开心散含药血清（500mg·kg-1）、阳性药氟西汀含药血清（10mg·kg-1）、普通大鼠血清。细胞实验中采用皮质酮损伤CTXTNA2细胞建立体外抑郁模型,MTT法检测开心散对皮质酮所致细胞损伤的影响以及磷脂酰肌醇3-激酶（phosphatidylinositol 3-kinase,P13K）信号通路抑制剂的干预作用;采用Western Blotting法检验相关信号通路蛋白表达变化情况。结果：皮质酮浓度为200μm01·L-1时,细胞活力抑制率可稳定在60％,浓度依赖性较好;开心散含药血清均能够显著提高皮质酮损伤细胞的存活率,而给予P13K相关通路的抑制剂后,开心散保护作用被逆转,Western Blotting结果显示给予开心散含药血清能够逆转皮质酮损伤后P13K及蛋白激酶B（protein kinase B,AKT）1／2蛋白表达下降的趋势。结论：开心散含药血清对皮质酮所致的CTXTNA2细胞损伤具有明显保护作用,其保护机制可能与P13K信号通路有关。  相似文献   

6.
Objective： To investigate the effect ofberbamine on human hepatoma cell line SMMC7721. Methods： The effects of 24 h and 48 h incubation with different concentrations （0-64 μg/ml） of the berbamine on SMMC7721 cells were evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide （MTT） assay. Hoechst 33258 staining was conducted to distinguish the apoptotic cell, and the appearance of sub-G1 stage was determined by PI （propidium iodide） staining, the percentage of apoptotic cell was determined by flow cytometry following annexin V/PI staining. Flow cytometry was performed to analyze the cell cycle distribution and the mitochondrial membrane potential （△ψm）, the expression of activated caspase3 and caspase9 was analyzed by Western-blot. Results： The proliferation of SMMC7721 was decreased after treatment with berbamine in a dose- and time-dependent manner. Berbamine could induce apoptosis in SMMC7721 cells and could cause cell cycle arrest in G0/G1 phase, to induce loss of mitochondrial membrane potential （AVm） and activate caspase3 and caspase9. Berbamine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk. Conclusion： Berbamine exerts antiproliferative effects on human hepatocellular carcinoma SMMC7721 cells. The anticancer activity of berbamine could be attributed partly to its inhibition of cell proliferation and induction of apoptosis in cancer cells through loss in mitochondrial transmembrane potential and caspase activation.  相似文献   

7.
Objective： To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy. Methods： lschemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons （CGNs） by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential, mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation （OGD）. Results： The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential （its maximal protection ratio was 73.26%） and release of cytochrome c （its maximal inhibition ratio was 42.52%） and the subsequent activation of caspase-3 （its maximal protection ratio was 59.32%） in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential. Conclusion： Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfiusion.  相似文献   

8.

Objective

Mesenchymal stem cell (MSC) transplantation is a promising therapy for ischemic heart diseases. However, poor cell survival after transplantation greatly limits the therapeutic efficacy of MSCs. The purpose of this study was to investigate the protective effect of angiopoietin-1 (Ang1) preconditioning on MSC survival and subsequent heart function improvement after transplantation.

Methods

MSCs were cultured with or without 50 ng/ml Ang1 in complete medium for 24 h prior to experiments on cell survival and transplantation. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst staining were applied to evaluate MSC survival after serum deprivation in vitro, while cell survival in vivo was detected by terminal deoxynucleotidyl transferase biotin-dUPT nick end labeling (TUNEL) assay 24 and 72 h after transplantation. Heart function and infarct size were measured four weeks later by small animal echocardiography and Masson??s trichrome staining, respectively.

Results

Ang1 preconditioning induced Akt phosphorylation and increased expression of Bcl-2 and the ratio of Bcl-2/Bax. In comparison with non-preconditioned MSCs, Ang1-preconditioned cell survival was significantly increased while the apoptotic rate decreased in vitro. However, the PI3K/Akt pathway inhibitor, LY294002, abrogated the protective effect of Ang1 preconditioning. After transplantation, the Ang1-preconditioned-MSC group showed a lower death rate, smaller infarct size, and better heart functional recovery compared to the non-preconditioned-MSC group.

Conclusions

Ang1 preconditioning enhances MSC survival, contributing to further improvement of heart function.  相似文献   

9.
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10.
Inflammation plays an important role in the development of acute lung injury (ALI). Severe pulmonary inflammation can cause acute respiratory distress syndrome (ARDS) or even death. Expression of proinflammatory interleukin-‍1β (IL-‍1β) and inducible nitric oxide synthase (iNOS) in the process of pulmonary inflammation will further exacerbate the severity of ALI. The purpose of this study was to explore the effect of Palrnatine (Pa) on lipopolysaccharide (LPS)-induced mouse ALI and its underlying mechanism. Pa, a natural product, has a wide range of pharmacological activities with the potential to protect against lung injury. Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed to detect the expression and translation of inflammatory genes and proteins in vitro and in vivo. Immunoprecipitation was used to detect the degree of P65 translocation into the nucleus. We also used molecular modeling to further clarify the mechanism of action. The results showed that Pa pretreatment could significantly inhibit the expression and secretion of the inflammatory cytokine IL-1β, and significantly reduce the protein level of the proinflammatory protease iNOS, in both in vivo and in vitro models induced by LPS. Further mechanism studies showed that Pa could significantly inhibit the activation of the protein kinase B (Akt)/nuclear factor-κB (NF-κB) signaling pathway in the LPS-induced ALI mode and in LPS-induced RAW264.7 cells. Through molecular dynamics simulation, we observed that Pa was bound to the catalytic pocket of Akt and effectively inhibited the biological activity of Akt. These results indicated that Pa significantly relieves LPS-induced ALI by activating the Akt/NF-κB signaling pathway.  相似文献   

11.
This paper aims to investigate the effects of artesunate (ART) on growth and apoptosis in human osteosarcoma HOS cell line in vitro and in vivo and to explore the possible underlying mechanisms. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The induction of apoptosis was detected by light and transmission electron microscopy and flow cytometry. Western blot analysis was used to investigate the related mechanisms. Nude mice were further employed to investigate the antitumour activity of ART in vivo. MTT assay results demonstrated that ART selectively inhibits the growth of HOS cells in a dose- and time-dependent manner. Based on the findings of light and transmission electron microscopy, Hoechst 33258 staining, and fluorescein isothiocyanate (FITC)-annexin V staining, the cytotoxicity of ART in HOS cells occurs through apoptosis. With ART treatment, cytosolic cytochrome c was increased, Bax expression was gradually upregulated, Bcl-2 expression was downregulated, and caspase-9 and caspase-3 were activated. Thus, the intrinsic apoptotic pathway may be involved in ART-induced apoptosis. Cell cycle analysis by flow cytometry indicated that ART may induce cell cycle arrest at G2/M phase. In nude mice bearing HOS xenograft tumours, ART inhibited tumour growth and regulated the expressions of cleaved caspase-3 and survivin, in agreement with in vitro observations. ART has a selective antitumour activity against human osteosarcoma HOS cells, which may be related to its effects on induction of apoptosis via the intrinsic pathway. The results suggest that ART is a promising candidate for the treatment of osteosarcoma.  相似文献   

12.
We hypothesized whether systemic administration of high-molecular-weight hyaluronic acid (HMW HA) could rescue trinitrobenzene sulfonic acid (TNBS)-induced colitis through Toll-like receptor 4 (TLR4) signal. C3H/HeN mice and C3H/HeJ mice were used. Mice were divided into four groups: control, 50% ethanol treatment group, TNBS treatment group, and TNBS plus HA treatment group. The weight changes, clinical scores, macroscopic scores, and histological scores were recorded. Cyclooxygenase 2 (Cox-2) and prostaglandin E2 (PGE2) expressions were measured both in colons and peritoneal macrophages from these mice. HA was a rescue therapy for the colitis induced by TNBS only in C3H/HeN mice. The clinical score, macroscopic score, and histological score were much lower in C3H/HeN mice receiving TNBS plus HA treatment. Cox-2 and PGE2 expressions only increased in C3H/HeN mice. These Cox-2 expressing cells were macrophages. HA can also promote the production of Cox-2 and PGE2 in peritoneal macrophages from C3H/HeN mice. Our data demonstrated that HMW HA can rescue TNBS-induced colitis through inducing Cox-2 and PGE2 expressions in a TLR4-dependent way. Macrophages may be the effector cells of HMW HA.  相似文献   

13.
以硝酸钾为中心金属离子,1,4-苯二甲酸（H2BDC）、1,3,5-苯三甲酸（H3BTC）及混合物（H2BDC+H3BTC）为有机配体,N,N-二甲基甲酰胺（DMF）为溶剂,采用溶剂热法合成三种K-MOF晶体。通过X射线粉末衍射(PXRD)、红外光谱(FT-IR)、扫描电镜（SEM）及热重(TG)等方法对样品进行表征,考察不同配体对K-MOF的影响。结果表明:K+与H2BDC配位得到的长条状晶体,与H3BTC配位得到粉末状晶体,H2BDC与H3BTC同时存在时,K+优先与H3BTC配位得到粉末状晶体。K-MOF具有良好的热稳定性,在350℃内能保持结构的热稳定性。  相似文献   

14.
This study was to investigate the responses of phospholipase D (PLD) and lipoxygenase (LOX) to mechanical wounding in postharvest cucumber (Cucumis sativus L. cv. Biyu-2) fruits. Membrane-associated Ca2+ content, activities and gene expression of PLD and LOX, and contents of phosphatidylcholine (PC), phosphatidylinositol (PI), and phosphatidic acid (PA) were determined in cucumber fruits following mechanical wounding. Results show that PLD and LOX activities increased with the PLD and LOX mRNAs which are upregulated upon wounding, while membrane-associated Ca2+ content decreased. Accompanying with the increase of PLD and LOX activities, accumulation of PA and losses of PC and PI were observed in all fruits, but there were differences of degrees between wounded and control fruits. Results suggest that PLD and LOX might be the main hydrolytic enzymes of phospholipids in postharvest cucumber fruits participating in the mechanical wounding injury. The activation of PLD and LOX might be the result of gene expression, which could be stimulated by the Ca2+ flowing from the membrane to the cytoplasm upon receiving the wounding signals.  相似文献   

15.
This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 µmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway.  相似文献   

16.
本研究旨在探索UV-B胁迫条件下不同生长调节剂对烟草幼苗抗逆性的影响。实验利用3,3-二氨基联苯胺(3,3-diaminobenzidine,DAB)染色方法定性检测胁迫条件下施用外源植物生长调节剂后植物叶片中H2O2的变化。通过实验发现,与空白对照组比较,UV-B处理组叶脉中H2O2积累显著,这可能由于UV-B对烟草幼苗的胁迫作用较明显。另外,植物生长调节剂处理可从一定程度上提高烟草幼苗在UV-B胁迫下的抗逆性,其中以GA和6-BA+IAA双重处理效果最好。  相似文献   

17.
We introduced a new class of fuzzy set-valued variational inclusions with （H,η）-monotone mappings. Using the resolvent operator method in Hilbert spaces, we suggested a new proximal point algorithm for finding approximate solutions, which strongly converge to the exact solution of a fuzzy set-valued variational inclusion with （H,η）-monotone. The results improved and generalized the general quasi-variational inclusions with fuzzy set-valued mappings proposed by Jin and Tian [Jin MM, Perturbed proximal point algorithm for general quasi-variational inclusions with fuzzy set-valued mappings, OR Transactions, 2005, 9（3）： 31-38, （In Chinese）; Tian YX, Generalized nonlinear implicit quasi-variational inclusions with fuzzy mappings, Computers ＆ Mathematics with Applications, 2001, 42： 101-108].  相似文献   

18.
[目的]研究三氧化二砷对K562细胞凋亡的诱导.[方法]采用人红白血病细胞株K562细胞常规培养,给不同浓度的三氧化二砷,在不同的时间收获细胞,用台盼蓝排染法,DNA荧光染料Hoechst33342荧光染色法,及碘化丙啶(PI)与Hoechst33342共染计数坏死细胞的PI阳性率等方法,检测其对K562细胞的影响.[结果]三氧化二砷能够诱导K562细胞凋亡.并且呈现浓度依赖性和时间依赖性.[结论]三氧化二砷主要以诱导肿瘤细胞凋亡而表现其毒性作用.  相似文献   

19.
苄基取代茚基二价稀土配合物的合成与表征   总被引：3，自引：0，他引：3  
无水EuCl3与1—苄基茚基钾在四氢呋喃(THF)中以1／2的摩尔比反应，尔后用Na／K合金原位进行还原，得到了一种新的中性的二(1—苄基茚基)稀土Ⅱ配合物(1—PhCH2C9H6)2Eu(THF)2；而用SmI2与1—苄基茚基钾在THF中以1／2的摩尔比反应，合成了一种新的苄基取代茚基稀土二价配合物(1—PhCH2C9H6)2Sm(THE)2，并对其进行了元素分析及红外光谱的表征。  相似文献   

20.
It has been reported that Ethaselen shows inhibitory effects on thioredoxin reductase (TrxR) activity and human tumor cell growth. In order to find an efficient way to reverse cisplatin resistance, we investigated the reversal effects of Ethaselen on cisplatin resistance in K562/cisplatin (CDDP) cells that were established by pulse-inducing human erythrocyte leukemic cell line K562, which are fivefold more resistant to cisplatin compared to K562 cells. The morphology and growth showed that the adhesion of K562/CDDP further decreased while the cell volume increased. The proliferation of K562/CDDP is strengthened. The antitumor activities in vitro were assessed by MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and combination index (CI), showing the significant synergic effects of cisplatin and Ethaselen. Focusing on apoptosis, a series of comparisons was made between K562 and K562/CDDP. Cisplatin induced higher reactive oxygen species (ROS) generation in K562 and subsequently induced the formation of mitochondrial permeability transition pores (PTPs). In addition, cisplatin increased the ratio of Bax to Bcl-2 in K562, which can influence the mitochondrial membrane permeability. PTP formation and mitochondrial membrane permeabilization eventually resulted in the release of cytochrome c and activation of the Caspase pathway. However, these effects were not clearly seen in K562/CDDP, which may be the reason for the acquired CDDP resistance. However, Ethaselen can induce a high level of ROS in K562/CDDP by TrxR activity inhibition and increased ratio of Bax to Bcl-2 in K562/CDDP by nuclear factor κB (NF-κB) suppression, which subsequently induces the release of cytochrome c in K562/CDDP. This response is partly responsible for the reversal of the cisplatin resistance in K562/CDDP cells.  相似文献   

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