Evidence suggests that autophagy may be a new therapeutic target for stroke, but whether acti- vation of autophagy increases or decreases the rate of neuronal death is still under debate. This review summarizes the po...Evidence suggests that autophagy may be a new therapeutic target for stroke, but whether acti- vation of autophagy increases or decreases the rate of neuronal death is still under debate. This review summarizes the potential role and possible signaling pathway of autophagy in neuronal survival after cerebral ischemia and proposes that autophagy has dual effects.展开更多
Tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a critical role in diverse cellular events, including cell proliferation, differentiation and apoptosis. TNF is also involved in many types of disea...Tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a critical role in diverse cellular events, including cell proliferation, differentiation and apoptosis. TNF is also involved in many types of diseases. In recent years, the molecular mechanisms of TNF functions have been intensively investigated. Studies from many laboratories have demonstrated that the TNF-mediated diverse biological responses are achieved through activating multiple signal- ing pathways. Especially the activation of transcription factors NF-κB and AP-1 plays a critical role in mediating these cellular responses. Several proteins, including FADD, the death domain kinase RIP and the TNF receptor associated factor TRAF2 have been identified as the key effectors of TNF signaling. Recently, we found that the effector mol- ecules of TNF signaling, such as RIP and TRAF2, are also involved in other cellular responses. These finding suggests that RIP and TRAF2 serve a broader role than as just an effector of TNF signaling.展开更多
AIM: To observe the protective effect of Radix Astragali injection on immune organs (lymph nodes, spleen and thymus) of rats with obstructive jaundice (OJ) and its mechanism. METHODS: SD rats were randomly divided int...AIM: To observe the protective effect of Radix Astragali injection on immune organs (lymph nodes, spleen and thymus) of rats with obstructive jaundice (OJ) and its mechanism. METHODS: SD rats were randomly divided into sham-operation group, model control group and Radix Astragali treatment group. On days 7, 14, 21 and 28 after operation, mortality rate of rats, pathological changes in immune organs, expression levels of Bax and nuclear factor (NF)-κB p65 proteins, apoptosis indexes and serum tumor necrosis factor (TNF)-α level in spleen and thymus were observed, respectively.RESULTS: Compared to model control group, the number of dead OJ rats in Radix Astragali treatment group decreased (P > 0.05). The TNF-α level (27.62 ± 12.61 vs 29.55 ± 18.02, 24.61 ± 9.09 vs 31.52 ± 10.95) on days 7 and 21, the pathological severity score for spleen [0.0 (0.0) vs 0.0 (2.0) on days 7 and 14 and for lymph nodes [0.0 (1.0) vs 1.0 (2.0), 1.0 (0.0) vs 2.0 (1.0)] on days 21 and 28, the product staining intensity and positive rate of Bax protein in spleen [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5) and thymus [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5)] on days 14 and 28, the apoptotic indexes [0.0 (0.0) vs 0.0 (0.01)] in spleen and thymus [0.0 (0.0) vs 0.0 (0.01) on days 14 and 21 were significantly lower in Radix Astragali treatment group than in model control group (P < 0.05). CONCLUSION: Radix Astragali has protective effects on immune organs of OJ rats by relieving the pathological changes in immune organs, reducing TNF-α level and inhibiting Bax expression and apoptosis in spleen and thymus.展开更多
The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae（Gegen）,salvia miltiorrhiza（Danshen）,radix curcuma（Jianghuang）,hawthorn（Shanzha）,salvia chinensis（Shijianchuan）,sinapis alba（Baiji...The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae（Gegen）,salvia miltiorrhiza（Danshen）,radix curcuma（Jianghuang）,hawthorn（Shanzha）,salvia chinensis（Shijianchuan）,sinapis alba（Baijiezi）,astragalus（Huangqi）,panax japonicas（Zhujieshen）,atractylodes macrocephala koidz（Baizhu）,radix paeoniae alba（Baishao）,bupleurum（Chaihu）,chrysanthemum（Juhua）,rhizoma cyperi（Xiangfu） and gastrodin（Tianma）,whose aqueous extract was fermented with lactobacillus,bacillus aceticus and saccharomycetes.ShuanTong-Ling is a formula used to treat brain diseases including ischemic stroke,migraine,and vascular dementia.Shuan-Tong-Ling attenuated H_2O_2-induced oxidative stress in rat microvascular endothelial cells.However,the potential mechanism involved in these effects is poorly understood.Rats were intragastrically treated with 5.7 or 17.2 m L/kg Shuan-Tong-Ling for 7 days before middle cerebral artery occlusion was induced.The results indicated Shuan-Tong-Ling had a cerebral protective effect by reducing infarct volume and increasing neurological scores.Shuan-Tong-Ling also decreased tumor necrosis factor-α and interleukin-1β levels in the hippocampus on the ischemic side.In addition,Shuan-Tong-Ling upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of acetylated-protein 53 and Bax.Injection of 5 mg/kg silent information regulator 1（SIRT1） inhibitor EX527 into the subarachnoid space once every 2 days,four times,reversed the above changes.These results demonstrate that Shuan-Tong-Ling might benefit cerebral ischemia/reperfusion injury by reducing inflammation and apoptosis through activation of the SIRT1 signaling pathway.展开更多
Anti-tumor necrosis factor(TNF) antibodies are successfully used in the therapy of inflammatory bowel diseases(IBD). However, the molecular mechanism of action of these agents is still a matter of debate. Apart from n...Anti-tumor necrosis factor(TNF) antibodies are successfully used in the therapy of inflammatory bowel diseases(IBD). However, the molecular mechanism of action of these agents is still a matter of debate. Apart from neutralization of TNF, influence on the intestinal barrier function, induction of apoptosis in mucosal immune cells, formation of regulatory macrophages as well as other immune modulating properties have been discussed as central features. Nevertheless, clinically effective anti-TNF antibodies were shown to differ in their mode-of-action in vivo and in vitro. Furthermore, the anti-TNF agent etanercept is effective in the treatment of rheumatoid arthritis but failed to induce clinical response in Crohn's disease patients, suggesting different contributions of TNF in the pathogenesis of these inflammatory diseases. In the following, we will review different aspects regarding the mechanism of action of anti-TNF agents in general and analyze comparatively different effects of each antiTNF agent such as TNF neutralization, modulation of the immune system, reverse signaling and induction of apoptosis. We discuss the relevance of the membranebound form of TNF compared to the soluble form for the immunopathogenesis of IBD. Furthermore, we review reports that could lead to personalized medicine approaches regarding treatment with antiTNF antibodies in chronic intestinal inflammation, by predicting response to therapy.展开更多
As post-mitotic cells with great energy demands, neurons depend upon the homeostatic and waste-recycling functions provided by autophagy. In addition, autophagy also promotes survival during periods of harsh stress an...As post-mitotic cells with great energy demands, neurons depend upon the homeostatic and waste-recycling functions provided by autophagy. In addition, autophagy also promotes survival during periods of harsh stress and targets aggregate-prone proteins associated with neurodegeneration for degradation. Despite this, autophagy has also been controversially described as a mechanism of programmed cell death. Instances of autophagic cell death are typically associated with elevated numbers of cytoplasmic autophagosomes, which have been assumed to lead to excessive degradation of cellular components. Due to the high activity and reliance on autophagy in neurons, these cells may be particularly susceptible to autophagic death. In this review, we summarize and assess current evidence in support of autophagic cell death in neurons, as well as how the dysregulation of autophagy commonly seen in neurodegeneration can contribute to neuron loss. From here, we discuss potential treatment strategies relevant to such cell-death pathways.展开更多
Objective To investigate the in vitro effect of caffeic acid phenethyl ester （CAPE）, a NF-KB inhibitor, on the apoptosis of osteoarthritic （OA） chondrocytes and on the regulation of the gelatinases matrix metallop...Objective To investigate the in vitro effect of caffeic acid phenethyl ester （CAPE）, a NF-KB inhibitor, on the apoptosis of osteoarthritic （OA） chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 （MMP-2） and matrix metalloproteinase 9 （MMP-9）. Methods Annexin V-FITC/propidium iodide （PI） labeling and western blotting were used to observe and determine the apoptosis in TNFa-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants. Results it was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFa for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated （from proMMP-9 to active MMP-9）, and the physiologic calcium concentration （2.5 mmol/L） could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFa for 24 h. The stimulatory effect of TNFa just on proMMP-9 was counteracted significantly by CAPE. Conclusion NF-KB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFa （a pro-apoptotic factor）. Therefore, therapeutic NF-KB inhibitor was a ＇double-edged swords＇ to the apoptosis of chondrocytes and the secretion of MMP-9.展开更多
AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma ...AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expre展开更多
Background Little is known about neuronal death mechanisms following spinal cord ischemia. The present study aimed to investigate the protective effect of pentoxifylline （PTX） against spinal cord ischemia/reperfusi...Background Little is known about neuronal death mechanisms following spinal cord ischemia. The present study aimed to investigate the protective effect of pentoxifylline （PTX） against spinal cord ischemia/reperfusion （I/R） injury. Methods Rabbits sustained spinal cord ischemia following 45 minutes cross-clamping of the infrarenal aorta. Experimental groups were as follows： the first group of animals （sham, n=-8） underwent laparotomy alone and served as the sham group; the second group （I/R, n=20） received carrier （3 ml saline solution） and served as the control group; the third group （PTX-A, n=20） received PTX intravenously 10 minutes prior to ischemia; and the fourth group （PTX-B, n=20） received PTX intravenously at the onset of reperfusion. Rabbits were evaluated for hind-limb motor function with the Tarlov scoring system at 48 hours. Serum was assayed with enzyme-linked immunosorbent assay for tumor necrosis factor α （TNF-α） and spinal cords were harvested for myeloperoxidase （MPO） activity, histopathological analysis, terminal deoxynucleotidyl transferase （TdT）-rnediated dUTP nick end labeling staining, platelet/endothelial ceU adhesion molecule-1 （PECAM-1） and caspase-3 immunohistochemistry, and the number of necrotic and apoptotic neuron were counted and data analyzed at 12, 24, 48 and 72 hours of reperfusion. Spinal cords were studied by electron microscopy. Results Improved Tarlov scores were seen in PTX-treated rabbits as compared with ischemic control rabbits at 48 hours. A significant reduction was found in TNF-α in serum, activity of MPO and immunoreactivity of the PECAM-1 and caspase-3 in PTX-treated rabbits. There were fewer apoptotic neurons than necrotic neurons （P 〈0.05）. A significant decrease in both necrotic and apoptotic neurons was observed in the PTX-treated groups （PTX-A and PTX-B） compared with the I/R group （P 〈0.05）. Both necrotic and apoptotic neurons were found with the electron microscope. Conclusions PTX may induce pro展开更多
AIM： TO investigate the severity of acute pancreatitis （AP） is associated to the intensity of leukocyte activation, inflammatory up-regulation and microcirculatory disruption associated to ischernia-reperfusion inj...AIM： TO investigate the severity of acute pancreatitis （AP） is associated to the intensity of leukocyte activation, inflammatory up-regulation and microcirculatory disruption associated to ischernia-reperfusion injury. Hicrovascular integrity and inhibition of pro-inflammatory mediators are key-factors in the evolution of AP. Relaxin is an insulin-like hormone that has been attributed vasorelaxant properties via the nitric oxide pathway while behaving as a glucocorticoid receptor agonist. METHODS： AP was induced by the bilio-pancreatic duct-outlet-exclusion closed-duodenal-loops model. Treatment with relaxin was done at different timepoints. Nitric oxide synthase inhibition by L-NAME and glucocorticoid receptor （GR） blockage by mifepristone was considered. AP severity was assessed by biochemical and histopathological analyses. RESULTS： Treatment with relaxin reduced serum amylase, lipase, C-reactive protein, IL-6, IL-10, hsp72, LDH and 8-isoprostane as well as pancreatic and lung myeloperoxidase. Acinar and fat necrosis, hemorrhage and neutrophil infiltrate were also decreased. ATP depletion and ADP/ATP ratio were reduced while caspases 2-3-8 and 9 activities were increased. L-NAME and mifepristone decreased the efficiency of relaxin. CONCLUSION： Relaxin resulted beneficial in the treatment of AP combining the properties of a GR agonist while preserving the microcirculation and favoring apoptosis over necrosis.展开更多
Objective Oxidative stress plays an important role in retinal pigmental epithelium （RPE） death during aging and the development of age-related macular degeneration.Although early reports indicate that reactive oxyge...Objective Oxidative stress plays an important role in retinal pigmental epithelium （RPE） death during aging and the development of age-related macular degeneration.Although early reports indicate that reactive oxygen species （ROS） including H2O2 can trigger apoptosis at lower concentrations and necrosis at higher concentrations,the exact molecular mechanism of RPE death is still unclear.The purpose of this study was to investigate the molecular pathways involved in RPE death induced by exogenous ROS,especially at higher concentrations.Methods Cultured ARPE-19 cells were treated with H2O2 at different concentrations and cell viability was measured with the MTT assay.Cell death was morphologically studied by microscopy using APOPercentage assay and PI staining.Furthermore,the impact of oxidative stress on ARPE-19 cells was assessed by HO-1 and PARP-1 Western blotting and by the protection of antioxidant EGCG.Calcium influx was determined using the fura-2 calcium indicator and the role of intracellular calcium overload in ARPE-19 cell death was evaluated following cobalt treatment to block calcium effects.Results H2O2 reduced the viability of ARPE-19 cells in a concentration-dependent manner,which was presented as a typical s-shaped curve.Cell death caused by high concentrations of H2O2 was confirmed to be programmed necrosis.Morphologically,dying ARPE-19 cells were extremely swollen and lost the integrity of their plasma membrane,positively detected with APOPercentage assay and PI staining.24-hour treatment with 500 ？mol/L H2O2 induced remarkable up-regulation of HO-1 and PARP-1 in ARPE-19 cells.Moreover,antioxidant treatment using EGCG effectively protected cells from H2O2-induced injury,increasing cell viability from 14.17%±2.31% to 85.77%±4.58%.After H2O2 treatment,intracellular calcium levels were highly elevated with a maximum concentration of 1200nM.Significantly,the calcium channel inhibitor cobalt was able to blunt this calcium influx and blocked the necrotic pathway,rescuing the ARPE-19 cell fr展开更多
Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ�...Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ’s physiological function. For long, only apoptosis was considered as a sole form of programmed cell death. Recently necroptosis, a RIP1/RIP3-dependent programmed cell death, has been identified as an apoptotic backup cell death mechanism with necrotic morphology. The evidences of necroptosis and protective effects achieved by blocking necroptosis have been extensively reported in recent past. However, only a few studies reported the evidence of necroptosis and protective effects achieved by inhibiting necroptosis in liver related disease conditions. Although the number of necroptosis initiators is increasing; however, interestingly, it is still unclear that what actually triggers necroptosis in different liver diseases or if there is always a different necroptosis initiator in each specific disease condition followed by specific downstream signaling molecules. Understanding the precise mechanism of necroptosis as well as counteracting other cell death pathways in liver diseases could provide a useful insight towards achieving extensive therapeutic significance. By targeting necroptosis and/or other parallel death pathways, a significant cell loss and thus a decrement in an organ’s physiological function can be prevented.展开更多
Objective To study the effect of γ-interferon （IFNγ）, tumor necrosis factor related apoptosis inducing ligand （TRAIL）, and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and it...Objective To study the effect of γ-interferon （IFNγ）, tumor necrosis factor related apoptosis inducing ligand （TRAIL）, and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and its possible molecular mechanisms. Methods The expressions of Caspase 8 mRNA and protein were detected with RT-PCR and Western blot analysis. The effects of IFNγ, TRAIL, IFNγ ＋ TRAIL, IFNγ ＋ Caspase 8 inhibitor ＋ TRAIL, IFNγ ＋ cisplatin ＋ TRAIL, and IFNγ ＋ etoposide ＋ TRAIL on the growth and apoptosis of SH-SY5Y cells were detected with the methods of MTT and flow cytometry. The relative Caspase 8 activity was measured with colorimetric assay. Results Caspase 8 was undetectable in SH-SY5Y cells but an increased expression of Caspase 8 mRNA and protein was found after treatment with IFNγ. SH-SY5Y ceils themselves were not sensitive to TRAIL, but those expressing Caspase 8 after treatment with IFNγ were. The killing effect of TRAIL on SH-SY5Y cells expressing Caspase 8 was depressed by Caspase 8 inhibitor. Cisplatin and etoposide could enhance the sensitivity of TRAIL on SH-SY5Y cells. The relative Caspase 8 activity of SH-SY5Y cells in IFNγ ＋ TRAIL group was significantly higher than those of control group, IFNγ group, TRAIL group, and inhibitor group （ P 〈 0. 01 ）. There was no significant difference among IFNγ ＋ TRAIL group, IFNγ ＋ cisplatin ＋ TRAIL group, and IFNγ ＋ etoposide ＋ TRAIL group. Conclusions IFNγ could sensitize SH-SY5Y cells to TRAIL-induced apoptosis and this may be realized by the up-regulation of Caspase 8. Cisplatin and etoposide could enhance the killing effect of TRAIL on SH-SY5Y cells.展开更多
AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resis...AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resistance in hepatocellular carcinoma(HCC)and to study the efficacy of agonistic TRAIL antibodies,as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS:Surface expression of TRAIL receptors (TRAIL-R1-4)and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting,respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNAs.HCC cellswere treated with kinase inhibitors and chemotherapeutic drugs.Apoptosis induction and cell viability were analyzed via flow cytometry and 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS:TRAIL-R1 and-R2 were profoundly expressed on the HCC cell lines Huh7 and Hep-G2. However,treatment of Huh7 and Hep-G2 with TRAIL and agonistic antibodies only induced minor apoptosis rates.Apoptosis resistance towards TRAIL could be considerably reduced by adding the chemotherapeutic drugs 5-fluorouracil and doxorubicin as well as the kinase inhibitors LY294002[inhibition of phosphoinositol- 3-kinase(PI3K)],AG1478(epidermal growth factor receptor kinase),PD98059(MEK1),rapamycin(mam- malian target of rapamycin)and the multi-kinase inhibitor Sorafenib.Furthermore,the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL play a major role in TRAIL resistance:knock-down by RNA interference increased TRAIL-induced apoptosis of HCC cells.Additionally, knock-down of MCL-1 and BCL-xL led to a significant sensitization of HCC cells towards inhibition of both c-Jun N-terminal kinase and PI3K.CONCLUSION:Our data identify the blockage of survival kinases,combination with chemotherapeutic drugs and targeting of antiapoptotic BCL-2 proteins as promising ways to overcome TRAIL resistance in HCC.展开更多
The immune checkpoints,cytotoxic T-lymphocyte-associated antigen 4(CTLA-4) and programmed cell death protein-1/ligand-1(PD-1/PD-L1) are vital contributors to immune resulation and tolerance.Recently immune checkpoint ...The immune checkpoints,cytotoxic T-lymphocyte-associated antigen 4(CTLA-4) and programmed cell death protein-1/ligand-1(PD-1/PD-L1) are vital contributors to immune resulation and tolerance.Recently immune checkpoint inhibitors(ICIs) have revolutionized cancer therapy;however,they come with the cost of immune related adverse events involving multiple organs such as the liver.Due to its constant expo sure to foreign antigens,the liver has evolved a high capacity for immune tolerance,therefore,blockade of the immune checkpoints can result in aberrant immune activation affecting the liver in up to 20% of patients depending on the agent(s) used and underlying factors.This type of hepatotoxicity is termed immune mediated liver injury from checkpoint inhibitors(ILICI) and is more common when CTLA4 and PD-1/PDL1 are used in combination.The underlying mechanisms of this unique type of hepatotoxicity are not fully understood;however,the contribution of CD8^(+) cytotoxic T lymphocytes,various CD4^(+) T cells populations,cytokines,and the secondary activation of the innate immune system leading to liver injury have all been suggested.This review summarizes our current understanding of the underlying mechanisms of liver injury in immunotherapy using animal models of ILICI and available patient data from clinical studies.展开更多
基金supported by grants from the project of National Natural Science Foundation of China,No.31171014 and 31371065the project of Science and Technology Commission of Board of Health of Shanghai,China,No.20134125the Key Specialty(disease) Declaration of Pudong New Area’s Health System
文摘Evidence suggests that autophagy may be a new therapeutic target for stroke, but whether acti- vation of autophagy increases or decreases the rate of neuronal death is still under debate. This review summarizes the potential role and possible signaling pathway of autophagy in neuronal survival after cerebral ischemia and proposes that autophagy has dual effects.
文摘Tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a critical role in diverse cellular events, including cell proliferation, differentiation and apoptosis. TNF is also involved in many types of diseases. In recent years, the molecular mechanisms of TNF functions have been intensively investigated. Studies from many laboratories have demonstrated that the TNF-mediated diverse biological responses are achieved through activating multiple signal- ing pathways. Especially the activation of transcription factors NF-κB and AP-1 plays a critical role in mediating these cellular responses. Several proteins, including FADD, the death domain kinase RIP and the TNF receptor associated factor TRAF2 have been identified as the key effectors of TNF signaling. Recently, we found that the effector mol- ecules of TNF signaling, such as RIP and TRAF2, are also involved in other cellular responses. These finding suggests that RIP and TRAF2 serve a broader role than as just an effector of TNF signaling.
基金Supported by Technological Foundation Project of Traditional Chinese Medicine of Zhejiang Province, No. 2003C130, No. 2004C142Foundation Project for Medical Science and Technology of Zhejiang Province, No. 2003B134+3 种基金Grave foundation project for Technology and Development of Hangzhou, No. 2003123B19Intensive Foundation Project for Technology of Hangzhou, No. 2004Z006Foundation Project for Medical Science and Technology of Hangzhou, No. 2003A004Foundation Project for Technology of Hangzhou, No. 2005224
文摘AIM: To observe the protective effect of Radix Astragali injection on immune organs (lymph nodes, spleen and thymus) of rats with obstructive jaundice (OJ) and its mechanism. METHODS: SD rats were randomly divided into sham-operation group, model control group and Radix Astragali treatment group. On days 7, 14, 21 and 28 after operation, mortality rate of rats, pathological changes in immune organs, expression levels of Bax and nuclear factor (NF)-κB p65 proteins, apoptosis indexes and serum tumor necrosis factor (TNF)-α level in spleen and thymus were observed, respectively.RESULTS: Compared to model control group, the number of dead OJ rats in Radix Astragali treatment group decreased (P > 0.05). The TNF-α level (27.62 ± 12.61 vs 29.55 ± 18.02, 24.61 ± 9.09 vs 31.52 ± 10.95) on days 7 and 21, the pathological severity score for spleen [0.0 (0.0) vs 0.0 (2.0) on days 7 and 14 and for lymph nodes [0.0 (1.0) vs 1.0 (2.0), 1.0 (0.0) vs 2.0 (1.0)] on days 21 and 28, the product staining intensity and positive rate of Bax protein in spleen [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5) and thymus [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5)] on days 14 and 28, the apoptotic indexes [0.0 (0.0) vs 0.0 (0.01)] in spleen and thymus [0.0 (0.0) vs 0.0 (0.01) on days 14 and 21 were significantly lower in Radix Astragali treatment group than in model control group (P < 0.05). CONCLUSION: Radix Astragali has protective effects on immune organs of OJ rats by relieving the pathological changes in immune organs, reducing TNF-α level and inhibiting Bax expression and apoptosis in spleen and thymus.
基金supported by the National Natural Science Foundation of China,No.81202625Open Fund of Key Laboratory of Cardiovascular and Cerebrovascular Diseases Translational Medicine of China Three Gorges University of China,No.2016xnxg101
文摘The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae（Gegen）,salvia miltiorrhiza（Danshen）,radix curcuma（Jianghuang）,hawthorn（Shanzha）,salvia chinensis（Shijianchuan）,sinapis alba（Baijiezi）,astragalus（Huangqi）,panax japonicas（Zhujieshen）,atractylodes macrocephala koidz（Baizhu）,radix paeoniae alba（Baishao）,bupleurum（Chaihu）,chrysanthemum（Juhua）,rhizoma cyperi（Xiangfu） and gastrodin（Tianma）,whose aqueous extract was fermented with lactobacillus,bacillus aceticus and saccharomycetes.ShuanTong-Ling is a formula used to treat brain diseases including ischemic stroke,migraine,and vascular dementia.Shuan-Tong-Ling attenuated H_2O_2-induced oxidative stress in rat microvascular endothelial cells.However,the potential mechanism involved in these effects is poorly understood.Rats were intragastrically treated with 5.7 or 17.2 m L/kg Shuan-Tong-Ling for 7 days before middle cerebral artery occlusion was induced.The results indicated Shuan-Tong-Ling had a cerebral protective effect by reducing infarct volume and increasing neurological scores.Shuan-Tong-Ling also decreased tumor necrosis factor-α and interleukin-1β levels in the hippocampus on the ischemic side.In addition,Shuan-Tong-Ling upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of acetylated-protein 53 and Bax.Injection of 5 mg/kg silent information regulator 1（SIRT1） inhibitor EX527 into the subarachnoid space once every 2 days,four times,reversed the above changes.These results demonstrate that Shuan-Tong-Ling might benefit cerebral ischemia/reperfusion injury by reducing inflammation and apoptosis through activation of the SIRT1 signaling pathway.
基金Supported by DFG-CRC1181-Project number(C02)a research operating grant from the International Organization for the Study of Inflammatory Bowel Diseases
文摘Anti-tumor necrosis factor(TNF) antibodies are successfully used in the therapy of inflammatory bowel diseases(IBD). However, the molecular mechanism of action of these agents is still a matter of debate. Apart from neutralization of TNF, influence on the intestinal barrier function, induction of apoptosis in mucosal immune cells, formation of regulatory macrophages as well as other immune modulating properties have been discussed as central features. Nevertheless, clinically effective anti-TNF antibodies were shown to differ in their mode-of-action in vivo and in vitro. Furthermore, the anti-TNF agent etanercept is effective in the treatment of rheumatoid arthritis but failed to induce clinical response in Crohn's disease patients, suggesting different contributions of TNF in the pathogenesis of these inflammatory diseases. In the following, we will review different aspects regarding the mechanism of action of anti-TNF agents in general and analyze comparatively different effects of each antiTNF agent such as TNF neutralization, modulation of the immune system, reverse signaling and induction of apoptosis. We discuss the relevance of the membranebound form of TNF compared to the soluble form for the immunopathogenesis of IBD. Furthermore, we review reports that could lead to personalized medicine approaches regarding treatment with antiTNF antibodies in chronic intestinal inflammation, by predicting response to therapy.
基金funded by a Wellcome Trust Principal Research Fellowshipthe NIHR Biomedical Research Unit in Dementia at Addenbrooke’s Hospitalsupported by Plymouth University and Northcott Medical Foundation
文摘As post-mitotic cells with great energy demands, neurons depend upon the homeostatic and waste-recycling functions provided by autophagy. In addition, autophagy also promotes survival during periods of harsh stress and targets aggregate-prone proteins associated with neurodegeneration for degradation. Despite this, autophagy has also been controversially described as a mechanism of programmed cell death. Instances of autophagic cell death are typically associated with elevated numbers of cytoplasmic autophagosomes, which have been assumed to lead to excessive degradation of cellular components. Due to the high activity and reliance on autophagy in neurons, these cells may be particularly susceptible to autophagic death. In this review, we summarize and assess current evidence in support of autophagic cell death in neurons, as well as how the dysregulation of autophagy commonly seen in neurodegeneration can contribute to neuron loss. From here, we discuss potential treatment strategies relevant to such cell-death pathways.
文摘Objective To investigate the in vitro effect of caffeic acid phenethyl ester （CAPE）, a NF-KB inhibitor, on the apoptosis of osteoarthritic （OA） chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 （MMP-2） and matrix metalloproteinase 9 （MMP-9）. Methods Annexin V-FITC/propidium iodide （PI） labeling and western blotting were used to observe and determine the apoptosis in TNFa-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants. Results it was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFa for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated （from proMMP-9 to active MMP-9）, and the physiologic calcium concentration （2.5 mmol/L） could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFa for 24 h. The stimulatory effect of TNFa just on proMMP-9 was counteracted significantly by CAPE. Conclusion NF-KB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFa （a pro-apoptotic factor）. Therefore, therapeutic NF-KB inhibitor was a ＇double-edged swords＇ to the apoptosis of chondrocytes and the secretion of MMP-9.
基金the National Natural Science Foundation of China,No.39870850
文摘AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expre
文摘Background Little is known about neuronal death mechanisms following spinal cord ischemia. The present study aimed to investigate the protective effect of pentoxifylline （PTX） against spinal cord ischemia/reperfusion （I/R） injury. Methods Rabbits sustained spinal cord ischemia following 45 minutes cross-clamping of the infrarenal aorta. Experimental groups were as follows： the first group of animals （sham, n=-8） underwent laparotomy alone and served as the sham group; the second group （I/R, n=20） received carrier （3 ml saline solution） and served as the control group; the third group （PTX-A, n=20） received PTX intravenously 10 minutes prior to ischemia; and the fourth group （PTX-B, n=20） received PTX intravenously at the onset of reperfusion. Rabbits were evaluated for hind-limb motor function with the Tarlov scoring system at 48 hours. Serum was assayed with enzyme-linked immunosorbent assay for tumor necrosis factor α （TNF-α） and spinal cords were harvested for myeloperoxidase （MPO） activity, histopathological analysis, terminal deoxynucleotidyl transferase （TdT）-rnediated dUTP nick end labeling staining, platelet/endothelial ceU adhesion molecule-1 （PECAM-1） and caspase-3 immunohistochemistry, and the number of necrotic and apoptotic neuron were counted and data analyzed at 12, 24, 48 and 72 hours of reperfusion. Spinal cords were studied by electron microscopy. Results Improved Tarlov scores were seen in PTX-treated rabbits as compared with ischemic control rabbits at 48 hours. A significant reduction was found in TNF-α in serum, activity of MPO and immunoreactivity of the PECAM-1 and caspase-3 in PTX-treated rabbits. There were fewer apoptotic neurons than necrotic neurons （P 〈0.05）. A significant decrease in both necrotic and apoptotic neurons was observed in the PTX-treated groups （PTX-A and PTX-B） compared with the I/R group （P 〈0.05）. Both necrotic and apoptotic neurons were found with the electron microscope. Conclusions PTX may induce pro
基金Supported by a research grant given to Dr Laura Iris CosenBinker by GlaxoSmithKline S.A.
文摘AIM： TO investigate the severity of acute pancreatitis （AP） is associated to the intensity of leukocyte activation, inflammatory up-regulation and microcirculatory disruption associated to ischernia-reperfusion injury. Hicrovascular integrity and inhibition of pro-inflammatory mediators are key-factors in the evolution of AP. Relaxin is an insulin-like hormone that has been attributed vasorelaxant properties via the nitric oxide pathway while behaving as a glucocorticoid receptor agonist. METHODS： AP was induced by the bilio-pancreatic duct-outlet-exclusion closed-duodenal-loops model. Treatment with relaxin was done at different timepoints. Nitric oxide synthase inhibition by L-NAME and glucocorticoid receptor （GR） blockage by mifepristone was considered. AP severity was assessed by biochemical and histopathological analyses. RESULTS： Treatment with relaxin reduced serum amylase, lipase, C-reactive protein, IL-6, IL-10, hsp72, LDH and 8-isoprostane as well as pancreatic and lung myeloperoxidase. Acinar and fat necrosis, hemorrhage and neutrophil infiltrate were also decreased. ATP depletion and ADP/ATP ratio were reduced while caspases 2-3-8 and 9 activities were increased. L-NAME and mifepristone decreased the efficiency of relaxin. CONCLUSION： Relaxin resulted beneficial in the treatment of AP combining the properties of a GR agonist while preserving the microcirculation and favoring apoptosis over necrosis.
基金supported by grants from the Natural Science Foundation of China (30801271)the Changchun Science and Technology Development Fund (08SF39)the International Joint Project from Science and Technology Bureau of Jilin Province (20090746)
文摘Objective Oxidative stress plays an important role in retinal pigmental epithelium （RPE） death during aging and the development of age-related macular degeneration.Although early reports indicate that reactive oxygen species （ROS） including H2O2 can trigger apoptosis at lower concentrations and necrosis at higher concentrations,the exact molecular mechanism of RPE death is still unclear.The purpose of this study was to investigate the molecular pathways involved in RPE death induced by exogenous ROS,especially at higher concentrations.Methods Cultured ARPE-19 cells were treated with H2O2 at different concentrations and cell viability was measured with the MTT assay.Cell death was morphologically studied by microscopy using APOPercentage assay and PI staining.Furthermore,the impact of oxidative stress on ARPE-19 cells was assessed by HO-1 and PARP-1 Western blotting and by the protection of antioxidant EGCG.Calcium influx was determined using the fura-2 calcium indicator and the role of intracellular calcium overload in ARPE-19 cell death was evaluated following cobalt treatment to block calcium effects.Results H2O2 reduced the viability of ARPE-19 cells in a concentration-dependent manner,which was presented as a typical s-shaped curve.Cell death caused by high concentrations of H2O2 was confirmed to be programmed necrosis.Morphologically,dying ARPE-19 cells were extremely swollen and lost the integrity of their plasma membrane,positively detected with APOPercentage assay and PI staining.24-hour treatment with 500 ？mol/L H2O2 induced remarkable up-regulation of HO-1 and PARP-1 in ARPE-19 cells.Moreover,antioxidant treatment using EGCG effectively protected cells from H2O2-induced injury,increasing cell viability from 14.17%±2.31% to 85.77%±4.58%.After H2O2 treatment,intracellular calcium levels were highly elevated with a maximum concentration of 1200nM.Significantly,the calcium channel inhibitor cobalt was able to blunt this calcium influx and blocked the necrotic pathway,rescuing the ARPE-19 cell fr
基金Supported by A grant of the Korea Healthcare technology R and D Project,Ministry of Health and Welfare,South Korea,NO.A121185
文摘Cell death has been extensively evaluated for decades and it is well recognized that pharmacological interventions directed to inhibit cell death can prevent significant cell loss and can thus improve an organ’s physiological function. For long, only apoptosis was considered as a sole form of programmed cell death. Recently necroptosis, a RIP1/RIP3-dependent programmed cell death, has been identified as an apoptotic backup cell death mechanism with necrotic morphology. The evidences of necroptosis and protective effects achieved by blocking necroptosis have been extensively reported in recent past. However, only a few studies reported the evidence of necroptosis and protective effects achieved by inhibiting necroptosis in liver related disease conditions. Although the number of necroptosis initiators is increasing; however, interestingly, it is still unclear that what actually triggers necroptosis in different liver diseases or if there is always a different necroptosis initiator in each specific disease condition followed by specific downstream signaling molecules. Understanding the precise mechanism of necroptosis as well as counteracting other cell death pathways in liver diseases could provide a useful insight towards achieving extensive therapeutic significance. By targeting necroptosis and/or other parallel death pathways, a significant cell loss and thus a decrement in an organ’s physiological function can be prevented.
基金the National Natural Sciences Foundation of China(39470739)the Ministry of Public Health Research Foundation(20122167)the Doctor Startup-Natural Science Foundation of Li-aoning Province (20041047)
文摘Objective To study the effect of γ-interferon （IFNγ）, tumor necrosis factor related apoptosis inducing ligand （TRAIL）, and cisplatin or etoposide induced apoptosis in human neuroblastoma cell line SH-SY5Y and its possible molecular mechanisms. Methods The expressions of Caspase 8 mRNA and protein were detected with RT-PCR and Western blot analysis. The effects of IFNγ, TRAIL, IFNγ ＋ TRAIL, IFNγ ＋ Caspase 8 inhibitor ＋ TRAIL, IFNγ ＋ cisplatin ＋ TRAIL, and IFNγ ＋ etoposide ＋ TRAIL on the growth and apoptosis of SH-SY5Y cells were detected with the methods of MTT and flow cytometry. The relative Caspase 8 activity was measured with colorimetric assay. Results Caspase 8 was undetectable in SH-SY5Y cells but an increased expression of Caspase 8 mRNA and protein was found after treatment with IFNγ. SH-SY5Y ceils themselves were not sensitive to TRAIL, but those expressing Caspase 8 after treatment with IFNγ were. The killing effect of TRAIL on SH-SY5Y cells expressing Caspase 8 was depressed by Caspase 8 inhibitor. Cisplatin and etoposide could enhance the sensitivity of TRAIL on SH-SY5Y cells. The relative Caspase 8 activity of SH-SY5Y cells in IFNγ ＋ TRAIL group was significantly higher than those of control group, IFNγ group, TRAIL group, and inhibitor group （ P 〈 0. 01 ）. There was no significant difference among IFNγ ＋ TRAIL group, IFNγ ＋ cisplatin ＋ TRAIL group, and IFNγ ＋ etoposide ＋ TRAIL group. Conclusions IFNγ could sensitize SH-SY5Y cells to TRAIL-induced apoptosis and this may be realized by the up-regulation of Caspase 8. Cisplatin and etoposide could enhance the killing effect of TRAIL on SH-SY5Y cells.
基金Supported by Research grants from Merck KGaA,Darmstadt,Germany,to Schulze-Bergkamen H
文摘AIM:To analyze the effect of chemotherapeutic drugs and specific kinase inhibitors,in combination with the death receptor ligand tumor necrosis factor-related apoptosis inducing ligand(TRAIL),on overcoming TRAIL resistance in hepatocellular carcinoma(HCC)and to study the efficacy of agonistic TRAIL antibodies,as well as the commitment of antiapoptotic BCL-2 proteins, in TRAIL-induced apoptosis. METHODS:Surface expression of TRAIL receptors (TRAIL-R1-4)and expression levels of the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL were analyzed by flow cytometry and Western blotting,respectively. Knock-down of MCL-1 and BCL-xL was performed by transfecting specific small interfering RNAs.HCC cellswere treated with kinase inhibitors and chemotherapeutic drugs.Apoptosis induction and cell viability were analyzed via flow cytometry and 3-(4,5-Dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS:TRAIL-R1 and-R2 were profoundly expressed on the HCC cell lines Huh7 and Hep-G2. However,treatment of Huh7 and Hep-G2 with TRAIL and agonistic antibodies only induced minor apoptosis rates.Apoptosis resistance towards TRAIL could be considerably reduced by adding the chemotherapeutic drugs 5-fluorouracil and doxorubicin as well as the kinase inhibitors LY294002[inhibition of phosphoinositol- 3-kinase(PI3K)],AG1478(epidermal growth factor receptor kinase),PD98059(MEK1),rapamycin(mam- malian target of rapamycin)and the multi-kinase inhibitor Sorafenib.Furthermore,the antiapoptotic BCL-2 proteins MCL-1 and BCL-xL play a major role in TRAIL resistance:knock-down by RNA interference increased TRAIL-induced apoptosis of HCC cells.Additionally, knock-down of MCL-1 and BCL-xL led to a significant sensitization of HCC cells towards inhibition of both c-Jun N-terminal kinase and PI3K.CONCLUSION:Our data identify the blockage of survival kinases,combination with chemotherapeutic drugs and targeting of antiapoptotic BCL-2 proteins as promising ways to overcome TRAIL resistance in HCC.
文摘The immune checkpoints,cytotoxic T-lymphocyte-associated antigen 4(CTLA-4) and programmed cell death protein-1/ligand-1(PD-1/PD-L1) are vital contributors to immune resulation and tolerance.Recently immune checkpoint inhibitors(ICIs) have revolutionized cancer therapy;however,they come with the cost of immune related adverse events involving multiple organs such as the liver.Due to its constant expo sure to foreign antigens,the liver has evolved a high capacity for immune tolerance,therefore,blockade of the immune checkpoints can result in aberrant immune activation affecting the liver in up to 20% of patients depending on the agent(s) used and underlying factors.This type of hepatotoxicity is termed immune mediated liver injury from checkpoint inhibitors(ILICI) and is more common when CTLA4 and PD-1/PDL1 are used in combination.The underlying mechanisms of this unique type of hepatotoxicity are not fully understood;however,the contribution of CD8^(+) cytotoxic T lymphocytes,various CD4^(+) T cells populations,cytokines,and the secondary activation of the innate immune system leading to liver injury have all been suggested.This review summarizes our current understanding of the underlying mechanisms of liver injury in immunotherapy using animal models of ILICI and available patient data from clinical studies.
