BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticu...BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticulum(ER)stress-related apoptosis in rat hepatocyte BRL-3A cells.METHODS BRL-3A cells were treated with varying doses of dithiothreitol(DTT),and their viability and apoptosis were quantified by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry.The expression of ER stress-and apoptosis-related proteins was detected by Western blot analysis.The protease activity of calpain-2 was determined using a fluorescent substrate,Nsuccinyl-Leu-Leu-Val-Tyr-AMC.Intracellular Ca^2+content,and ER and calpain-2 co-localization were characterized by fluorescent microscopy.The impact of calpain-2 silencing by specific small interfering RNA on caspase-12 activation and apoptosis of BRL-3A cells was quantified.RESULTS DTT exhibited dose-dependent cytotoxicity against BRL-3A cells and treatment with 2 mmol/L DTT triggered BRL-3A cell apoptosis.DTT treatment significantly upregulated 78 kDa glucose-regulated protein,activating transcription factor 4,C/EBP-homologous protein expression by>2-fold,and enhanced PRKR-like ER kinase phosphorylation,caspase-12 and caspase-3 cleavage in BRL-3A cells in a trend of time-dependence.DTT treatment also significantly increased intracellular Ca^2+content,calpain-2 expression,and activity by>2-fold in BRL-3A cells.Furthermore,immunofluorescence revealed that DTT treatment promoted the ER accumulation of calpain-2.Moreover,calpain-2 silencing to decrease calpain-2 expression by 85%significantly mitigated DTT-enhanced calpain-2 expression,caspase-12 cleavage,and apoptosis in BRL-3A cells.CONCLUSION The data indicated that Ca^2+-dependent calpain-2 activity promoted the aberrant ER stress-related apoptosis of rat hepatocytes by activating caspase-12 in the ER.展开更多
目的:应用肌性斜颈兔动物模型,探讨针刀治疗肌性斜颈的作用机制及意义。方法:无水酒精注射制备动物肌性斜颈兔子模型后,选取模型兔子48只,随机分为正常组、模型组、针刀组、按摩组,每组12只。分别给予各组对应治疗,治疗2个月后各组分别...目的:应用肌性斜颈兔动物模型,探讨针刀治疗肌性斜颈的作用机制及意义。方法:无水酒精注射制备动物肌性斜颈兔子模型后,选取模型兔子48只,随机分为正常组、模型组、针刀组、按摩组,每组12只。分别给予各组对应治疗,治疗2个月后各组分别取部分胸锁乳突肌制作标本,免疫组化法观察钙蛋白酶1(calpain-1)、分化抗原决定簇45(CD45)、基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)、基质金属蛋白酶抑制因子2(tissue inhibitor of metalloproteinases-2,TIMP-2)在各组肌纤维中的表达情况。结果:与正常组比较,其余各组实验动物明显出现颈部活动受限、斜颈、头颈不对称症状,而治疗结束后,针刀组和按摩组实验动物颈部活动受限改善,无明显头颈不对称症状。calpain-1、CD45、TIMP-2的表达,与正常组比较,模型组、按摩组上调(P<0.01);与模型组比较,针刀组、按摩组下调(P<0.01);与针刀组比较,按摩组上调(P<0.01)。MMP-2表达,与正常组比较,模型组下调(P<0.01),与模型组比较,针刀组、按摩组上调(P<0.05)。结论:针刀治疗肌性斜颈效果显著,其作用机制可能与减少calpain-1、CD45、TIMP-2表达,增加MMP-2表达有关。展开更多
乙型肝炎病毒(hepatitis B virus,HBV)X蛋白(HBx)对肝癌的发生发展具有十分重要的作用.我们前期研究发现,HBx突变体(HBxΔ127)与肝癌的增殖和迁移有密切的关系.钙蛋白酶小亚基1(calpain small subunit 1,Capn4)具有促进细胞迁移、增殖...乙型肝炎病毒(hepatitis B virus,HBV)X蛋白(HBx)对肝癌的发生发展具有十分重要的作用.我们前期研究发现,HBx突变体(HBxΔ127)与肝癌的增殖和迁移有密切的关系.钙蛋白酶小亚基1(calpain small subunit 1,Capn4)具有促进细胞迁移、增殖和分化的作用.本研究对HBx突变体(HBxΔ127)促进肝癌细胞迁移的分子机制进行了研究.实验结果显示,HBxΔ127可明显激活Capn4的启动子活性和上调Capn4蛋白表达.应用ERK抑制剂PD98059作用肝癌细胞后,可明显抑制HBxΔ127对Capn4的上调作用,提示HBxΔ127可通过磷酸化ERK1/2(p-ERK1/2)上调Capn4.应用伤口愈合实验进一步证实,HBxΔ127促进肝癌细胞迁移的作用与Capn4和p-ERK1/2有关.本研究结果表明,HBxΔ127促进肝癌细胞迁移的作用是通过p-ERK1/2上调Capn4实现的.这一发现对进一步揭示HBx突变体HBxΔ127促进肝癌细胞转移的分子机制具有重要意义.展开更多
基金the National Natural Science Foundation of China,No.81560105the Department of Science and Technology of Guizhou Province,No.LH(2014)7074。
文摘BACKGROUND Calpain-2 is a Ca^2+-dependent cysteine protease,and high calpain-2 activity can enhance apoptosis mediated by multiple triggers.AIM To investigate whether calpain-2 can modulate aberrant endoplasmic reticulum(ER)stress-related apoptosis in rat hepatocyte BRL-3A cells.METHODS BRL-3A cells were treated with varying doses of dithiothreitol(DTT),and their viability and apoptosis were quantified by 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2-H-tetrazolium bromide and flow cytometry.The expression of ER stress-and apoptosis-related proteins was detected by Western blot analysis.The protease activity of calpain-2 was determined using a fluorescent substrate,Nsuccinyl-Leu-Leu-Val-Tyr-AMC.Intracellular Ca^2+content,and ER and calpain-2 co-localization were characterized by fluorescent microscopy.The impact of calpain-2 silencing by specific small interfering RNA on caspase-12 activation and apoptosis of BRL-3A cells was quantified.RESULTS DTT exhibited dose-dependent cytotoxicity against BRL-3A cells and treatment with 2 mmol/L DTT triggered BRL-3A cell apoptosis.DTT treatment significantly upregulated 78 kDa glucose-regulated protein,activating transcription factor 4,C/EBP-homologous protein expression by>2-fold,and enhanced PRKR-like ER kinase phosphorylation,caspase-12 and caspase-3 cleavage in BRL-3A cells in a trend of time-dependence.DTT treatment also significantly increased intracellular Ca^2+content,calpain-2 expression,and activity by>2-fold in BRL-3A cells.Furthermore,immunofluorescence revealed that DTT treatment promoted the ER accumulation of calpain-2.Moreover,calpain-2 silencing to decrease calpain-2 expression by 85%significantly mitigated DTT-enhanced calpain-2 expression,caspase-12 cleavage,and apoptosis in BRL-3A cells.CONCLUSION The data indicated that Ca^2+-dependent calpain-2 activity promoted the aberrant ER stress-related apoptosis of rat hepatocytes by activating caspase-12 in the ER.
文摘目的:应用肌性斜颈兔动物模型,探讨针刀治疗肌性斜颈的作用机制及意义。方法:无水酒精注射制备动物肌性斜颈兔子模型后,选取模型兔子48只,随机分为正常组、模型组、针刀组、按摩组,每组12只。分别给予各组对应治疗,治疗2个月后各组分别取部分胸锁乳突肌制作标本,免疫组化法观察钙蛋白酶1(calpain-1)、分化抗原决定簇45(CD45)、基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)、基质金属蛋白酶抑制因子2(tissue inhibitor of metalloproteinases-2,TIMP-2)在各组肌纤维中的表达情况。结果:与正常组比较,其余各组实验动物明显出现颈部活动受限、斜颈、头颈不对称症状,而治疗结束后,针刀组和按摩组实验动物颈部活动受限改善,无明显头颈不对称症状。calpain-1、CD45、TIMP-2的表达,与正常组比较,模型组、按摩组上调(P<0.01);与模型组比较,针刀组、按摩组下调(P<0.01);与针刀组比较,按摩组上调(P<0.01)。MMP-2表达,与正常组比较,模型组下调(P<0.01),与模型组比较,针刀组、按摩组上调(P<0.05)。结论:针刀治疗肌性斜颈效果显著,其作用机制可能与减少calpain-1、CD45、TIMP-2表达,增加MMP-2表达有关。
文摘乙型肝炎病毒(hepatitis B virus,HBV)X蛋白(HBx)对肝癌的发生发展具有十分重要的作用.我们前期研究发现,HBx突变体(HBxΔ127)与肝癌的增殖和迁移有密切的关系.钙蛋白酶小亚基1(calpain small subunit 1,Capn4)具有促进细胞迁移、增殖和分化的作用.本研究对HBx突变体(HBxΔ127)促进肝癌细胞迁移的分子机制进行了研究.实验结果显示,HBxΔ127可明显激活Capn4的启动子活性和上调Capn4蛋白表达.应用ERK抑制剂PD98059作用肝癌细胞后,可明显抑制HBxΔ127对Capn4的上调作用,提示HBxΔ127可通过磷酸化ERK1/2(p-ERK1/2)上调Capn4.应用伤口愈合实验进一步证实,HBxΔ127促进肝癌细胞迁移的作用与Capn4和p-ERK1/2有关.本研究结果表明,HBxΔ127促进肝癌细胞迁移的作用是通过p-ERK1/2上调Capn4实现的.这一发现对进一步揭示HBx突变体HBxΔ127促进肝癌细胞转移的分子机制具有重要意义.
