[目的]利用急性脊髓损伤SD大鼠动物模型,探讨E-64-d在脊髓损伤修复过程中的作用机制。[方法]制作大鼠脊髓损伤模型,将大鼠随机分为5组:对照组;单纯损伤组;E-64-d治疗组;MP治疗组;MP与E-64-d联合治疗组。给与钙蛋白酶抑制剂E-64-d和/或...[目的]利用急性脊髓损伤SD大鼠动物模型,探讨E-64-d在脊髓损伤修复过程中的作用机制。[方法]制作大鼠脊髓损伤模型,将大鼠随机分为5组:对照组;单纯损伤组;E-64-d治疗组;MP治疗组;MP与E-64-d联合治疗组。给与钙蛋白酶抑制剂E-64-d和/或甲基强的松龙(MP)腹腔注射。分别应用TUNEL法检测神经细胞的凋亡水平。免疫组化测定各时间点Calpain1与GFAP的表达变化;每天同一时间对大鼠进行后肢运动功能BBB评分及感觉功能评分。[结果]TUNEL检测显示,治疗组神经元细胞凋亡减少,Caspase-3的活性均减弱。损伤后脊髓组织中Calpain 1活性增加,应用E-64-d治疗后得到抑制。损伤后3 d Calpain 1和GFAP的表达增强,但治疗组显著低于损伤组。BBB运动功能评分显示,治疗组大鼠的运动功能得到增强,结果具有统计学意义。进一步实验结果显示,联合使用E-64-d和甲基强的松龙(MP)的效果要好于单独使用E-64-d或MP。[结论]E-64-d具有减轻急性大鼠脊髓损伤的作用,其与MP联合使用效果更加明显,Calpain抑制剂具有治疗脊髓损伤的潜力。展开更多
We developed a dietary exposure assay for screening insecticidal compounds for their toxicity and for assessing the side effects of insecticidal proteins produced by genetically engineered （GE） plants on the plantho...We developed a dietary exposure assay for screening insecticidal compounds for their toxicity and for assessing the side effects of insecticidal proteins produced by genetically engineered （GE） plants on the planthopper Laodelphax striatellus Fallen. The fitness bioassay confirmed that the diet fulfills the requirements to be used in the dietary exposure system. To validate the efficacy of the dietary exposure system, nymphs of L. striatellus were fed diets treated with different concentrations of an inorganic stomach poison, potassium arsenate （PA）, or a cysteine protease inhibitor, E-64. The results showed that with increasing concentrations of E-64, the larval development time was prolonged, the adult weight was reduced and the survival rate of L. striatellus was decreased. Similarly the survival rates of L. striatellus consistently decreased with increasing PA content in the diet. The data indicate that the dietary exposure assay is able to detect the effects of insecticidal compounds on L. striatellus. Subsequently, this assay was successfully used for assessing the potential toxicity of Cry2Aa. The results showed that L. striatellus larvae were not negatively affected when fed the artificial diet containing purified Cry2Aa at 300 μg/g diet. In the assay, the stability and bioactivity of crystal （Cry） proteins in the food sources were confirmed by enzyme-linked immunosorbent assay and sensitive-insect bioassays. These results show that L. striatellus is not sensitive to Cry2Aa. We conclude that the dietary exposure system is valid and useful for assessing the toxicity of insecticidal compounds produced by GE plants on planthoppers.展开更多
文摘[目的]利用急性脊髓损伤SD大鼠动物模型,探讨E-64-d在脊髓损伤修复过程中的作用机制。[方法]制作大鼠脊髓损伤模型,将大鼠随机分为5组:对照组;单纯损伤组;E-64-d治疗组;MP治疗组;MP与E-64-d联合治疗组。给与钙蛋白酶抑制剂E-64-d和/或甲基强的松龙(MP)腹腔注射。分别应用TUNEL法检测神经细胞的凋亡水平。免疫组化测定各时间点Calpain1与GFAP的表达变化;每天同一时间对大鼠进行后肢运动功能BBB评分及感觉功能评分。[结果]TUNEL检测显示,治疗组神经元细胞凋亡减少,Caspase-3的活性均减弱。损伤后脊髓组织中Calpain 1活性增加,应用E-64-d治疗后得到抑制。损伤后3 d Calpain 1和GFAP的表达增强,但治疗组显著低于损伤组。BBB运动功能评分显示,治疗组大鼠的运动功能得到增强,结果具有统计学意义。进一步实验结果显示,联合使用E-64-d和甲基强的松龙(MP)的效果要好于单独使用E-64-d或MP。[结论]E-64-d具有减轻急性大鼠脊髓损伤的作用,其与MP联合使用效果更加明显,Calpain抑制剂具有治疗脊髓损伤的潜力。
文摘We developed a dietary exposure assay for screening insecticidal compounds for their toxicity and for assessing the side effects of insecticidal proteins produced by genetically engineered （GE） plants on the planthopper Laodelphax striatellus Fallen. The fitness bioassay confirmed that the diet fulfills the requirements to be used in the dietary exposure system. To validate the efficacy of the dietary exposure system, nymphs of L. striatellus were fed diets treated with different concentrations of an inorganic stomach poison, potassium arsenate （PA）, or a cysteine protease inhibitor, E-64. The results showed that with increasing concentrations of E-64, the larval development time was prolonged, the adult weight was reduced and the survival rate of L. striatellus was decreased. Similarly the survival rates of L. striatellus consistently decreased with increasing PA content in the diet. The data indicate that the dietary exposure assay is able to detect the effects of insecticidal compounds on L. striatellus. Subsequently, this assay was successfully used for assessing the potential toxicity of Cry2Aa. The results showed that L. striatellus larvae were not negatively affected when fed the artificial diet containing purified Cry2Aa at 300 μg/g diet. In the assay, the stability and bioactivity of crystal （Cry） proteins in the food sources were confirmed by enzyme-linked immunosorbent assay and sensitive-insect bioassays. These results show that L. striatellus is not sensitive to Cry2Aa. We conclude that the dietary exposure system is valid and useful for assessing the toxicity of insecticidal compounds produced by GE plants on planthoppers.
