Objective： The mechanisms by which lipopolysaccharide （LPS） pretreatment induces cardioprotection following ischaemia/reperfusion （I/R） have not been fully elucidated. We hypothesized that activation of phosphoin...Objective： The mechanisms by which lipopolysaccharide （LPS） pretreatment induces cardioprotection following ischaemia/reperfusion （I/R） have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase （PI3K）/Akt and high mobility group box 1 （HMGBxl） signaling plays an important role in LPS-induced cardioprotection. Methods： In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride （TTC） staining. Akt, phospho-Akt, and HMGBxl were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apop- tosis was examined by the TdT-mediated dUTP nick-end labeling （TUNEL） assay. In an in vitro study, rat cardiac myoblasts （H9c2） were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% 02. Levels of HMGBxl were assessed by immunoblot. Results： In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBxl. In the in vitro study, pretreatment with LPS reduced the level of HMGBxl in H9c2 cell cytoplasm following hypoxia. Conclusion： The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBxl pathways.展开更多
AIM： To investigate the role of polo-like kinase 1 （PLK1） as a therapeutic target for hepatocellular carcinoma （HCC）. METHODS： PLK1 gene expression was evaluated in HCC tissue and HCC cell lines. Gene knockdown ...AIM： To investigate the role of polo-like kinase 1 （PLK1） as a therapeutic target for hepatocellular carcinoma （HCC）. METHODS： PLK1 gene expression was evaluated in HCC tissue and HCC cell lines. Gene knockdown with short-interfering RNA （siRNA） was used to study PLK1 gene and protein expression using real-time reverse transcription polymerase chain reaction （RT-PCR） and Western blotting, and cell proliferation using 3-（4,5-dim ethylthiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2（4-sulf ophenyl）-2H-tetrazolium （MTS） and bromodeoxyuridine （BrdU） assays. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end label- ing （TUNEL） assay, and caspase-inhibition assay. Huh-7 cells were transplanted into nude mice and co-cultured with PLK1 siRNA or control siRNA, and tumor progres- sion was compared with controls. RESULTS： RT-PCR showed that PLK1 was overexpre- ssed 12-fold in tumor samples compared with controls, and also was overexpressed in Huh-7 cells, siRNA against PLK1 showed a reduction in PLK1 gene and protein expression of up to 96% in Huh-7 cells, and a reduction in cell proliferation by 68% and 92% in MTS and BrdU cell proliferation assays, respectively. There was a 3-fold increase in apoptosis events, and TUNEL staining and caspase-3 assays suggested that this was caspase-independent. The pan-caspase inhibitor Z-VAD-FMK was unable to rescue the apoptotic cells. Immnofluorescence co-localized endonuclease-G to fragmented chromosomes, implicating it in apoptosis. Huh-7 cells transplanted subcutaneously into nude mice showed tumor regression in siPLKl-treated mice, but not in controls. CONCLUSION： Knockdown of PLK1 overexpression in HCC was shown to be a potential therapeutic target, leading to apoptosis through the endonuclease-G path- way.展开更多
Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible ...Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.展开更多
目的:观察电针对脑缺血大鼠前扣带皮质高迁移率族蛋白1(high mobility group protein 1,HMGB1)和磷酸化的c-Jun氨基酸末端激酶(phosphorylated c-Jun N-terminal kinase,p-JNK)的表达影响,探讨电针对脑缺血大鼠前扣带皮质的保护作用及...目的:观察电针对脑缺血大鼠前扣带皮质高迁移率族蛋白1(high mobility group protein 1,HMGB1)和磷酸化的c-Jun氨基酸末端激酶(phosphorylated c-Jun N-terminal kinase,p-JNK)的表达影响,探讨电针对脑缺血大鼠前扣带皮质的保护作用及机制。方法:将24只雄性SD大鼠随机分为假手术组、模型组、电针组和假电针组,6只/组。采用右侧大脑中动脉栓塞法制备脑缺血大鼠模型,电针组选取“百会”穴、左侧“足三里”穴进行电针刺激,1次/d,30 min/次,持续14 d;假电针组仅浅刺入两穴位皮下,接电针仪但不通电。采用Longa评分评估各组大鼠神经功能损伤情况;Nissl染色观察右侧前扣带皮质神经元的形态与分布情况;免疫组化检测右侧前扣带皮质HMGB1和p-JNK蛋白的表达情况。结果:与假手术组相比,模型组和假电针组大鼠神经功能缺损评分升高(P<0.01),右侧前扣带皮质区Nissl阳性神经元数量减少(P<0.01),HMGB1和p-JNK蛋白表达增加(P<0.01);与模型组相比,电针组大鼠在脑缺血第7天、14天时神经功能缺损评分降低(P<0.05),Nissl阳性神经元数量增加(P<0.01),HMGB1和p-JNK蛋白表达降低(P<0.01)。结论:电针可能通过抑制脑缺血后HMGB1和p-JNK的过表达,减轻前扣带皮质的损伤。展开更多
Objective Proprionibacterium acnes(P.acnes)-induced inflammatory responses,proliferation and differentiation of keratinocytes contribute to the progression of acne vulgaris(AV).P.acnes was found to enhance the product...Objective Proprionibacterium acnes(P.acnes)-induced inflammatory responses,proliferation and differentiation of keratinocytes contribute to the progression of acne vulgaris(AV).P.acnes was found to enhance the production of interleukin-8(IL-8)by keratinocytes.This study aimed to investigate the role of IL-8 in P.acnes-induced proliferation and differentiation of keratinocytes and the underlying mechanism.Methods The P.acnes-stimulated HaCaT cell(a human keratinocyte cell line)model was established.Western blotting and immunofluorescence were performed to detect the expression of the IL-8 receptors C-X-C motif chemokine receptor 1(CXCR1)and C-X-C motif chemokine receptor 2(CXCR2)on HaCaT cells.Cell counting kit-8(CCK-8)assay,5-ethynyl-20-deoxyuridine(EdU)assay and Western blotting were performed to examine the effects of IL-8/CXCR2 axis on the proliferation and differentiation of HaCaT cells treated with P.acnes,the IL-8 neutralizing antibody,the CXCR2 antagonist(SB225002),or the CXCR1/CXCR2 antagonist(G31P).Western blotting,nuclear and cytoplasmic separation,CCK-8 assay,and EdU assay were employed to determine the downstream pathway of CXCR2 after P.acnes-stimulated HaCaT cells were treated with the CXCR2 antagonist,the protein kinase B(AKT)antagonist(AZD5363),or the constitutively active forkhead box O1(FOXO1)mutant.Finally,autophagy markers were measured in HaCaT cells following the transfection of the FOXO1 mutant or treatment with the autophagy inhibitor 3-methyladenine(3-MA).Results The expression levels of CXCR1 and CXCR2 were significantly increased on the membrane of HaCaT cells following P.acnes stimulation.The IL-8/CXCR2 axis predominantly promoted the proliferation and differentiation of P.acnes-induced HaCaT cells by activating AKT/FOXO1/autophagy signaling.In brief,IL-8 bound to its receptor CXCR2 on the membrane of keratinocytes to activate the AKT/FOXO1 axis.Subsequently,phosphorylated FOXO1 facilitated autophagy to promote the proliferation and differentiation of P.acnes-induced keratinocytes.Conclusion This study demonstrated the novel autocrine effect of IL-8 on the proliferation and differentiation of P.acnes-induced keratinocytes,suggesting a potential therapeutic target for AV.展开更多
文摘Objective： The mechanisms by which lipopolysaccharide （LPS） pretreatment induces cardioprotection following ischaemia/reperfusion （I/R） have not been fully elucidated. We hypothesized that activation of phosphoinositide 3-kinase （PI3K）/Akt and high mobility group box 1 （HMGBxl） signaling plays an important role in LPS-induced cardioprotection. Methods： In in vivo experiments, age- and weight- matched male C57BL/10Sc wild type mice were pretreated with LPS before ligation of the left anterior descending coronary followed by reperfusion. Infarction size was examined by triphenyltetrazolium chloride （TTC） staining. Akt, phospho-Akt, and HMGBxl were assessed by immunoblotting with appropriate primary antibodies. In situ cardiac myocyte apop- tosis was examined by the TdT-mediated dUTP nick-end labeling （TUNEL） assay. In an in vitro study, rat cardiac myoblasts （H9c2） were subdivided into two groups, and only one was pretreated with LPS. After pretreatment, the cells were transferred into a hypoxic chamber under 0.5% 02. Levels of HMGBxl were assessed by immunoblot. Results： In the in vivo experiment, pretreatment with LPS reduced the at risk infarct size by 70.6% and the left ventricle infarct size by 64.93% respectively. Pretreatment with LPS also reduced cardiac myocytes apoptosis by 39.1% after ischemia and reperfusion. The mechanisms of LPS induced cardioprotection involved increasing PI3K/Akt activity and decreasing expression of HMGBxl. In the in vitro study, pretreatment with LPS reduced the level of HMGBxl in H9c2 cell cytoplasm following hypoxia. Conclusion： The results suggest that the cardioprotection following I/R induced by LPS pretreatment involves PI3K/Akt and HMGBxl pathways.
基金Supported by The National University of Singapore Grants,No.R-172-000-001-731 and No.R-172-000-024-731
文摘AIM： To investigate the role of polo-like kinase 1 （PLK1） as a therapeutic target for hepatocellular carcinoma （HCC）. METHODS： PLK1 gene expression was evaluated in HCC tissue and HCC cell lines. Gene knockdown with short-interfering RNA （siRNA） was used to study PLK1 gene and protein expression using real-time reverse transcription polymerase chain reaction （RT-PCR） and Western blotting, and cell proliferation using 3-（4,5-dim ethylthiazol-2-yl）-5-（3-carboxymethoxyphenyl）-2（4-sulf ophenyl）-2H-tetrazolium （MTS） and bromodeoxyuridine （BrdU） assays. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end label- ing （TUNEL） assay, and caspase-inhibition assay. Huh-7 cells were transplanted into nude mice and co-cultured with PLK1 siRNA or control siRNA, and tumor progres- sion was compared with controls. RESULTS： RT-PCR showed that PLK1 was overexpre- ssed 12-fold in tumor samples compared with controls, and also was overexpressed in Huh-7 cells, siRNA against PLK1 showed a reduction in PLK1 gene and protein expression of up to 96% in Huh-7 cells, and a reduction in cell proliferation by 68% and 92% in MTS and BrdU cell proliferation assays, respectively. There was a 3-fold increase in apoptosis events, and TUNEL staining and caspase-3 assays suggested that this was caspase-independent. The pan-caspase inhibitor Z-VAD-FMK was unable to rescue the apoptotic cells. Immnofluorescence co-localized endonuclease-G to fragmented chromosomes, implicating it in apoptosis. Huh-7 cells transplanted subcutaneously into nude mice showed tumor regression in siPLKl-treated mice, but not in controls. CONCLUSION： Knockdown of PLK1 overexpression in HCC was shown to be a potential therapeutic target, leading to apoptosis through the endonuclease-G path- way.
基金supported by a grant from the National Natural Sciences Foundation of China,No.81030019
文摘Alterations in embryonic neural stem cells play crucial roles in the pathogenesis of amyotrophic lateral sclerosis. We hypothesized that embryonic neural stem cells from SOD1G93A individuals might be more susceptible to oxidative injury, resulting in a propensity for neurodegeneration at later stages. In this study, embryonic neural stem cells obtained from human superoxide dis- mutase 1 mutant （SOD1G93A） and wild-type （SOD1wv） mouse models were exposed to H202. We assayed cell viability with mitochondrial succinic dehydrogenase colorimetric reagent, and measured cell apoptosis by flow cytometry. Moreover, we evaluated the expression of the adenos- ine monophosphate-activated protein kinase （AMPK） ct-subunit, paired box 3 （Pax3） protein, and p53 in western blot analyses. Compared with SOD1wr cells, SOD1~93A embryonic neural stem cells were more likely to undergo H202-induced apoptosis. Phosphorylation of AMPKct in SOD1G93A cells was higher than that in SOD1wr cells. Pax3 expression was inversely correlated with the phosphorylation levels of AMPKct. p53 protein levels were also correlated with AMPKct phosphorylation levels. Compound C, an inhibitor of AMPKa, attenuated the effects of H20~. These results suggest that embryonic neural stem cells from SOD1C93A mice are more susceptible to apoptosis in the presence of oxidative stress compared with those from wild-type controls, and the effects are mainly mediated by Pax3 and p53 in the AMPKa pathway.
文摘目的:观察电针对脑缺血大鼠前扣带皮质高迁移率族蛋白1(high mobility group protein 1,HMGB1)和磷酸化的c-Jun氨基酸末端激酶(phosphorylated c-Jun N-terminal kinase,p-JNK)的表达影响,探讨电针对脑缺血大鼠前扣带皮质的保护作用及机制。方法:将24只雄性SD大鼠随机分为假手术组、模型组、电针组和假电针组,6只/组。采用右侧大脑中动脉栓塞法制备脑缺血大鼠模型,电针组选取“百会”穴、左侧“足三里”穴进行电针刺激,1次/d,30 min/次,持续14 d;假电针组仅浅刺入两穴位皮下,接电针仪但不通电。采用Longa评分评估各组大鼠神经功能损伤情况;Nissl染色观察右侧前扣带皮质神经元的形态与分布情况;免疫组化检测右侧前扣带皮质HMGB1和p-JNK蛋白的表达情况。结果:与假手术组相比,模型组和假电针组大鼠神经功能缺损评分升高(P<0.01),右侧前扣带皮质区Nissl阳性神经元数量减少(P<0.01),HMGB1和p-JNK蛋白表达增加(P<0.01);与模型组相比,电针组大鼠在脑缺血第7天、14天时神经功能缺损评分降低(P<0.05),Nissl阳性神经元数量增加(P<0.01),HMGB1和p-JNK蛋白表达降低(P<0.01)。结论:电针可能通过抑制脑缺血后HMGB1和p-JNK的过表达,减轻前扣带皮质的损伤。
基金supported by the National Natural Science Foundation of China(No.82103756).
文摘Objective Proprionibacterium acnes(P.acnes)-induced inflammatory responses,proliferation and differentiation of keratinocytes contribute to the progression of acne vulgaris(AV).P.acnes was found to enhance the production of interleukin-8(IL-8)by keratinocytes.This study aimed to investigate the role of IL-8 in P.acnes-induced proliferation and differentiation of keratinocytes and the underlying mechanism.Methods The P.acnes-stimulated HaCaT cell(a human keratinocyte cell line)model was established.Western blotting and immunofluorescence were performed to detect the expression of the IL-8 receptors C-X-C motif chemokine receptor 1(CXCR1)and C-X-C motif chemokine receptor 2(CXCR2)on HaCaT cells.Cell counting kit-8(CCK-8)assay,5-ethynyl-20-deoxyuridine(EdU)assay and Western blotting were performed to examine the effects of IL-8/CXCR2 axis on the proliferation and differentiation of HaCaT cells treated with P.acnes,the IL-8 neutralizing antibody,the CXCR2 antagonist(SB225002),or the CXCR1/CXCR2 antagonist(G31P).Western blotting,nuclear and cytoplasmic separation,CCK-8 assay,and EdU assay were employed to determine the downstream pathway of CXCR2 after P.acnes-stimulated HaCaT cells were treated with the CXCR2 antagonist,the protein kinase B(AKT)antagonist(AZD5363),or the constitutively active forkhead box O1(FOXO1)mutant.Finally,autophagy markers were measured in HaCaT cells following the transfection of the FOXO1 mutant or treatment with the autophagy inhibitor 3-methyladenine(3-MA).Results The expression levels of CXCR1 and CXCR2 were significantly increased on the membrane of HaCaT cells following P.acnes stimulation.The IL-8/CXCR2 axis predominantly promoted the proliferation and differentiation of P.acnes-induced HaCaT cells by activating AKT/FOXO1/autophagy signaling.In brief,IL-8 bound to its receptor CXCR2 on the membrane of keratinocytes to activate the AKT/FOXO1 axis.Subsequently,phosphorylated FOXO1 facilitated autophagy to promote the proliferation and differentiation of P.acnes-induced keratinocytes.Conclusion This study demonstrated the novel autocrine effect of IL-8 on the proliferation and differentiation of P.acnes-induced keratinocytes,suggesting a potential therapeutic target for AV.
