BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription fact...BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription factor specific for endoplasmic reticulum stress, can cause cell cycle arrest and cell apoptosis. OBJECTIVE： To study the protective effects of serum containing natural cerebrolysin on endoplasmic reticulum stress in tunicamycin-induced neuronal PC12 cells, and analyze the influence on GRP78 and CHOP expressions. DESIGN, TIME AND SETTING： A parallel controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, between March 2006 and August 2008. MATERIALS： Adult Sprague-Dawley rats were perfused with natural Cerebrolysin aqueous extract （0.185 g/kg/d） to produce serum containing natural Cerebrolysin. Physiological saline was used to produce blank serum. PC12 cell line was provided by Shanghai Institute of Cell Biology, Chinese Academy of Science. Tunicamycin was provided by Sigma （St. Louis, USA）, and natural Cerebrolysin, containing ginseng, rhizoma gastrodiae, and gingko leaf （1：2：2）, by Shengzhen Institute of Integrated Western and Traditional Chinese Medicine. METHODS： PC12 cells were treated with DMEM culture media containing 10% blank serum （normal control group）, tunicamycin （1 μg/mL; model group）, and 5%, 10%, and 15% serum containing natural cerebrolysin and tunicamycin （1 μ g/mL; low-, moderate-, and high-dose serum containing natural cerebrotysin groups）, for 2 hours. MAIN OUTCOME MEASURES： PC12 cells were treated with tunicamycin for 48 hours after which apoptosis was measured using the TUNEL method to calculate apoptotic index. GRP78 expression was detected using immunocytochemistry. After 24 hours of treatment with tunicamycin, GRP78 and CHOP mRNA expressions were measured using RT-PCR. RESULTS： The apoptotic index and CHOP mRNA expression were in the model group and three cerebrolysin groups were significantly increased when compared to the normal control group （P 〈 0.05）. In contrast, GRP78 mRNA and protein expressions were significantly decreased （P 〈 0.05）. CONCLUSION： Serum containing natural cerebrolysin significantly reduced apoptosis in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress. These results may be related to an up-regulation of GRP78 expression and down-regulation of CHOP expression, both of which displayed dose-dependent effects.展开更多
目的观察血压正常大鼠和自发性高血压大鼠全脑缺血后海马区CCAAT/增强子结合蛋白同源蛋白(CCAAT/enhancer-binding protein homologous protein,CHOP)的表达变化,探讨其在高血压加重脑缺血神经损伤中的作用。方法分别取血压正常大鼠和...目的观察血压正常大鼠和自发性高血压大鼠全脑缺血后海马区CCAAT/增强子结合蛋白同源蛋白(CCAAT/enhancer-binding protein homologous protein,CHOP)的表达变化,探讨其在高血压加重脑缺血神经损伤中的作用。方法分别取血压正常大鼠和自发性高血压大鼠,应用改良的Pulsineli 4血管阻断(4-VO)法制作全脑缺血再灌注模型。分别在脑缺血6、24、48h应用HE染色观察海马区神经细胞形态变化、免疫组织化学法和免疫印迹法检测海马区CHOP表达;在48h应用八臂迷宫检测动物行为学的变化。结果与血压正常脑缺血组比较,高血压脑缺血组各时间点存活神经细胞数量减少,6h和24hCHOP表达增多,48h减少;八臂迷宫检测动物总错误次数、参考记忆错误次数和工作记忆错误次数增多。结论高血压可加重脑缺血后神经损伤,其机制与加重CHOP表达增加有关。展开更多
Computer assisted audit techniques （CAATs） are audit technologies that allow auditors to perform their audit work efficiently and effectively. However, little is known about CAATs adoption process by audit firms. Th...Computer assisted audit techniques （CAATs） are audit technologies that allow auditors to perform their audit work efficiently and effectively. However, little is known about CAATs adoption process by audit firms. Therefore, this paper adapts the technology readiness theory （TRI）, the unified theory of acceptance and use of technology （UTAUT） and the technology-organization environment （TOE） framework and Denison organizational culture theory, and presents a new theory of unified technology readiness and cultural-technological-organizational-environmental model （UTR-CTOE）, to explain CAATs adoption at both individual level and firm level. The methodology used in the study consists of a random sampling among the auditors through the administration of questionnaire. A total of 581 auditors registered with Mauritius Institute of Professional Accountants （MIPA） respond to the survey. Our main findings of this paper confirm that the relation between beliefs, such as perceived usefulness, perceived ease of use, facilitating condition and social influence, and motivation is positively correlated, while beliefs have a negative correlation with inhibition towards CAATs adoption. Results also indicate that firm＇s decision for CAATs adoption is positively influenced by cultural, technological, organizational, and environmental factors. Furthermore, there is an indirect impact of firm＇s internal and external influences on auditors＇ adoption of CAATs.展开更多
Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways...Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review.展开更多
Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the...Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of mitomycin C on the proliferation and apoptosis of human epidural scar fibroblasts. Human epidural scar fibroblasts were treated with various concentrations of mitomycin C （1, 5, 10, 20, 40 μg/mL） for 12, 24 and 48 hours. Mitomycin C suppressed the growth of these cells in a dose- and time-dependent manner. Mitomycin C upregulated the expression levels of Fas, DR4, DR5, cleaved caspase-8/9, Bax, Bim and cleaved caspase-3 proteins, and it downregulated Bcl-2 and Bcl-xL expression. In addition, inhibitors of caspase-8 and caspase-9 （Z-IETD-FMK and Z-LEHD-FMK, respectively） did not fully inhibit mitomycin C-induced apoptosis. Furthermore, mitomycin C induced endoplasmic reticulum stress by increasing the expression of glucose-regulated protein 78, CAAT/enhancer-binding protein homologous protein （CHOP） and caspase 4 in a dose-dependent manner. Salubrinal significantly inhibited the mitomycin C-induced cell viability loss and apoptosis, and these effects were accompanied by a reduction in CHOP expression. Our results support the hypothesis that mitomycin C induces human epidural scar fibroblast apoptosis, at least in part, via the endoplasmic reticulum stress pathway.展开更多
目的探讨CAAT增强子结合蛋白同源蛋白(CHOP)、海马葡萄糖调节蛋白78(GRP78)和caspase-12在蛛网膜下腔出血(SAH)后的表达及其在早期脑损伤(EBI)中的作用。方法选取健康雄性SD大鼠78只,采用随机数字表法将其分为空白对照组(6只)、假手术组...目的探讨CAAT增强子结合蛋白同源蛋白(CHOP)、海马葡萄糖调节蛋白78(GRP78)和caspase-12在蛛网膜下腔出血(SAH)后的表达及其在早期脑损伤(EBI)中的作用。方法选取健康雄性SD大鼠78只,采用随机数字表法将其分为空白对照组(6只)、假手术组(36只)与SAH组(36只)。将假手术组和SAH组分别于1、6、12、24、48、72h,采用简单随机抽样法选取6只大鼠,神经功能缺陷评分后处死。比较各组不同时间点光镜及电镜下大鼠海马神经元形态改变、CHOP、GRP78、caspase-12相对表达水平、海马神经元凋亡细胞水平、脑水肿严重程度及神经功能缺陷评分情况。结果通过Western blot法检测CHOP、GRP78和caspase-12的表达,SAH组与空白对照组、假手术组在12、24、48、72h比较,差异均有统计学意义(P<0.05),且在SAH后24h达到峰值。TUNEL法检测大鼠海马区神经元凋亡显示,SAH组与对照组、假手术组在6、12、24、48、72h比较,差异均有统计学意义(P<0.05),在电镜下,SAH后24h节点可见明显的神经元凋亡。SAH组12、24、48、72h的神经功能缺陷评分及脑水肿程度明显重于空白对照组及假手术组,在24h达高峰,差异均有统计学意义(P<0.05)。SAH组大鼠的CHOP、GRP78和caspase-12 Western blot法检测结果与脑水肿严重程度及神经元凋亡结果之间呈极显著正相关,与神经功能缺陷评分呈极显著负相关(P<0.05)。结论 SAH后72h内确实造成了EBI,同时发生了内质网应激,内质网应激与EBI严重程度之间均呈正相关,揭示内质网应激在SAH后EBI的病理过程中发挥了重要作用。展开更多
基金Supported by:Scientific and Technological Foundation of the National Administration of Traditional Chinese Medicine of China,No.02-03LP41the Scientific and Technological Key Project of Guangdong Province,No. 2006B35630007
文摘BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription factor specific for endoplasmic reticulum stress, can cause cell cycle arrest and cell apoptosis. OBJECTIVE： To study the protective effects of serum containing natural cerebrolysin on endoplasmic reticulum stress in tunicamycin-induced neuronal PC12 cells, and analyze the influence on GRP78 and CHOP expressions. DESIGN, TIME AND SETTING： A parallel controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, between March 2006 and August 2008. MATERIALS： Adult Sprague-Dawley rats were perfused with natural Cerebrolysin aqueous extract （0.185 g/kg/d） to produce serum containing natural Cerebrolysin. Physiological saline was used to produce blank serum. PC12 cell line was provided by Shanghai Institute of Cell Biology, Chinese Academy of Science. Tunicamycin was provided by Sigma （St. Louis, USA）, and natural Cerebrolysin, containing ginseng, rhizoma gastrodiae, and gingko leaf （1：2：2）, by Shengzhen Institute of Integrated Western and Traditional Chinese Medicine. METHODS： PC12 cells were treated with DMEM culture media containing 10% blank serum （normal control group）, tunicamycin （1 μg/mL; model group）, and 5%, 10%, and 15% serum containing natural cerebrolysin and tunicamycin （1 μ g/mL; low-, moderate-, and high-dose serum containing natural cerebrotysin groups）, for 2 hours. MAIN OUTCOME MEASURES： PC12 cells were treated with tunicamycin for 48 hours after which apoptosis was measured using the TUNEL method to calculate apoptotic index. GRP78 expression was detected using immunocytochemistry. After 24 hours of treatment with tunicamycin, GRP78 and CHOP mRNA expressions were measured using RT-PCR. RESULTS： The apoptotic index and CHOP mRNA expression were in the model group and three cerebrolysin groups were significantly increased when compared to the normal control group （P 〈 0.05）. In contrast, GRP78 mRNA and protein expressions were significantly decreased （P 〈 0.05）. CONCLUSION： Serum containing natural cerebrolysin significantly reduced apoptosis in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress. These results may be related to an up-regulation of GRP78 expression and down-regulation of CHOP expression, both of which displayed dose-dependent effects.
文摘目的观察血压正常大鼠和自发性高血压大鼠全脑缺血后海马区CCAAT/增强子结合蛋白同源蛋白(CCAAT/enhancer-binding protein homologous protein,CHOP)的表达变化,探讨其在高血压加重脑缺血神经损伤中的作用。方法分别取血压正常大鼠和自发性高血压大鼠,应用改良的Pulsineli 4血管阻断(4-VO)法制作全脑缺血再灌注模型。分别在脑缺血6、24、48h应用HE染色观察海马区神经细胞形态变化、免疫组织化学法和免疫印迹法检测海马区CHOP表达;在48h应用八臂迷宫检测动物行为学的变化。结果与血压正常脑缺血组比较,高血压脑缺血组各时间点存活神经细胞数量减少,6h和24hCHOP表达增多,48h减少;八臂迷宫检测动物总错误次数、参考记忆错误次数和工作记忆错误次数增多。结论高血压可加重脑缺血后神经损伤,其机制与加重CHOP表达增加有关。
文摘Computer assisted audit techniques （CAATs） are audit technologies that allow auditors to perform their audit work efficiently and effectively. However, little is known about CAATs adoption process by audit firms. Therefore, this paper adapts the technology readiness theory （TRI）, the unified theory of acceptance and use of technology （UTAUT） and the technology-organization environment （TOE） framework and Denison organizational culture theory, and presents a new theory of unified technology readiness and cultural-technological-organizational-environmental model （UTR-CTOE）, to explain CAATs adoption at both individual level and firm level. The methodology used in the study consists of a random sampling among the auditors through the administration of questionnaire. A total of 581 auditors registered with Mauritius Institute of Professional Accountants （MIPA） respond to the survey. Our main findings of this paper confirm that the relation between beliefs, such as perceived usefulness, perceived ease of use, facilitating condition and social influence, and motivation is positively correlated, while beliefs have a negative correlation with inhibition towards CAATs adoption. Results also indicate that firm＇s decision for CAATs adoption is positively influenced by cultural, technological, organizational, and environmental factors. Furthermore, there is an indirect impact of firm＇s internal and external influences on auditors＇ adoption of CAATs.
基金supported by the German Research Council(Deutsche Forschungsgemeinschaft,HA3309/3-1/2,HA3309/6-1,HA3309/7-1)。
文摘Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review.
基金supported by the National Natural Science Foundation of China,No.81401791,81371968,81672152
文摘Numerous studies have shown that topical application of mitomycin C after surgical decompression effectively reduces scar adhesion. However, the underlying mechanisms remain unclear. In this study, we investigated the effect of mitomycin C on the proliferation and apoptosis of human epidural scar fibroblasts. Human epidural scar fibroblasts were treated with various concentrations of mitomycin C （1, 5, 10, 20, 40 μg/mL） for 12, 24 and 48 hours. Mitomycin C suppressed the growth of these cells in a dose- and time-dependent manner. Mitomycin C upregulated the expression levels of Fas, DR4, DR5, cleaved caspase-8/9, Bax, Bim and cleaved caspase-3 proteins, and it downregulated Bcl-2 and Bcl-xL expression. In addition, inhibitors of caspase-8 and caspase-9 （Z-IETD-FMK and Z-LEHD-FMK, respectively） did not fully inhibit mitomycin C-induced apoptosis. Furthermore, mitomycin C induced endoplasmic reticulum stress by increasing the expression of glucose-regulated protein 78, CAAT/enhancer-binding protein homologous protein （CHOP） and caspase 4 in a dose-dependent manner. Salubrinal significantly inhibited the mitomycin C-induced cell viability loss and apoptosis, and these effects were accompanied by a reduction in CHOP expression. Our results support the hypothesis that mitomycin C induces human epidural scar fibroblast apoptosis, at least in part, via the endoplasmic reticulum stress pathway.
文摘目的探讨CAAT增强子结合蛋白同源蛋白(CHOP)、海马葡萄糖调节蛋白78(GRP78)和caspase-12在蛛网膜下腔出血(SAH)后的表达及其在早期脑损伤(EBI)中的作用。方法选取健康雄性SD大鼠78只,采用随机数字表法将其分为空白对照组(6只)、假手术组(36只)与SAH组(36只)。将假手术组和SAH组分别于1、6、12、24、48、72h,采用简单随机抽样法选取6只大鼠,神经功能缺陷评分后处死。比较各组不同时间点光镜及电镜下大鼠海马神经元形态改变、CHOP、GRP78、caspase-12相对表达水平、海马神经元凋亡细胞水平、脑水肿严重程度及神经功能缺陷评分情况。结果通过Western blot法检测CHOP、GRP78和caspase-12的表达,SAH组与空白对照组、假手术组在12、24、48、72h比较,差异均有统计学意义(P<0.05),且在SAH后24h达到峰值。TUNEL法检测大鼠海马区神经元凋亡显示,SAH组与对照组、假手术组在6、12、24、48、72h比较,差异均有统计学意义(P<0.05),在电镜下,SAH后24h节点可见明显的神经元凋亡。SAH组12、24、48、72h的神经功能缺陷评分及脑水肿程度明显重于空白对照组及假手术组,在24h达高峰,差异均有统计学意义(P<0.05)。SAH组大鼠的CHOP、GRP78和caspase-12 Western blot法检测结果与脑水肿严重程度及神经元凋亡结果之间呈极显著正相关,与神经功能缺陷评分呈极显著负相关(P<0.05)。结论 SAH后72h内确实造成了EBI,同时发生了内质网应激,内质网应激与EBI严重程度之间均呈正相关,揭示内质网应激在SAH后EBI的病理过程中发挥了重要作用。
