Little is known about changes in calpain activity in the pituitary gland. In the present study,μ- and m-calpain activity changes were detected in the rat anterior pituitary following intraperitoneal injection of diet...Little is known about changes in calpain activity in the pituitary gland. In the present study,μ- and m-calpain activity changes were detected in the rat anterior pituitary following intraperitoneal injection of diethylstilbestrol. Double-immunofluorescence labeling confirmed colocalization of μ- and m-calpain in prolactin-secreting cells （lactotrophs）. Western blot analysis revealed significantly increased expression of both calpains, which accompanied upregulated cytosol and membrane zymographic activities at 12 weeks following diethylstilbestrol injection, compared with rats injected with sunflower oil. Moreover, following estrogen injection, pituitary gland pathological damage gradually worsened with increasing time. Results demonstrated that estrogen regulated calpain expression and activity, and both calpains participated in the pathophysiological processes of the pituitary gland. Ubiquitous calpain expression could serve as an effective target for anti-estrogen drugs.展开更多
Detailed mechanisms behind regeneration after nerve injury, in particular signal transduction and the fate of Schwann cells （SCs）, are poorly understood. Here, we investigated axotomy-induced activation of extracell...Detailed mechanisms behind regeneration after nerve injury, in particular signal transduction and the fate of Schwann cells （SCs）, are poorly understood. Here, we investigated axotomy-induced activation of extracellular- signal-regulated kinase-1/2 （ERK1/2; important for proliferation） and m-calpain in vitro, and the relation to Ca2＋ deletion and Schwann cell proliferation and death after rat sciatic nerve axotomy. Nerve segments were cultured for up to 72 hours with and without ethylene glycol-bis（β-aminoethyl ether）- N,N,N＇,N＇-tetraacetic acid （EGTA）. In some experiments, 5-bromo-2′-deoxyuridine （BrdU） was added during the last 24 hours to detect proliferating cells and propidium iodide （PI） was added at the last hour to detect dead and/or dying cells. Immunohistochemistry of sections of the cultured nerve segments was performed to label m-calpain and the phosphorylated and activated form of ERK1/2. The experiments revealed that immunoreactivity for p-ERK1/2 increased with time in organotypically cultured SCs. p-ERK1/2 and m-calpain were also observed in axons. A significant increase in the number of dead or dying SCs was observed in nerve segments cultured for 24 hours. When deprived of Ca2＋, activation of axonal m-calpain was reduced, whereas p-ERK1/2 was increased in SCs. Ca2＋ deprivation also significantly reduced the number of proliferating SCs, and instead increased the number of dead or dying SCs. Ca2＋ seems to play an important role in activation of ERK1/2 in SCs and in SC survival and proliferation. In addition, extracellular Ca2＋ levels are also required for m-calpain activation and up-regulation in axons. Thus, regulation of Ca2＋ levels is likely to be a useful method to promote SC proliferation.展开更多
BACKGROUND： During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release p...BACKGROUND： During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin （PRL） and may promote formation of prolactin neoplasia in pituitary anterior lobe. OBJECTIVE： To observe the effect of diethylstilbestrol （DES） on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats. DESIGN： Observational contrast animal study. SETTING： Beijing Neurosurgical Institute. MATERIALS： A total of 21 female Wistar rats, 3 weeks old weighing 70-80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at （24±1）℃ and a humidity of （55±5）%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan. METHODS： The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil （1 mL/kg, twice a week） for 16 weeks; DES group, where animals were administered with DES （5 mg/kg, twice a week） for 16 weeks; DES ＋ vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil （1 mL/kg, twice a week） for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. MAIN OUTCOME MEASURES： ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue. RESULTS： All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination： Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone （ACTH） was increased in both DES group and DES ＋ vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES ＋ vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue： Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissueswere confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES ＋ vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES. CONCLUSION： A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe.展开更多
Calpains are ubiquitous non-lysosomal Ca2+-dependent cysteine proteases also present in myocardial cytosol and mitochondria.Numerous experimental studies reveal an essential role of the calpain system in myocardial in...Calpains are ubiquitous non-lysosomal Ca2+-dependent cysteine proteases also present in myocardial cytosol and mitochondria.Numerous experimental studies reveal an essential role of the calpain system in myocardial injury during ischemia,reperfusion and postischemic structural remodelling.The increasing Ca2+-content and Ca2+-overload in myocardial cytosol and mitochondria during ischemia and reperfusion causes an activation of calpains.Upon activation they are able to injure the contractile apparatus and impair the energy production by cleaving structural and functional proteins of myocytes and mitochondria.Besides their causal involvement in acute myocardial dysfunction they are also involved in structural remodelling after myocardial infarction by the generation and release of proapoptotic factors from mitochondria.Calpain inhibition can prevent or attenuate myocardial injury during ischemia,reperfusion,and in later stages of myocardial infarction.展开更多
Aging is a popular method used by meat industry for improving the sensory attributes of meat.Despite the advent of many novel technologies,aging has not lost its charm and is still widely used commercially as a post-m...Aging is a popular method used by meat industry for improving the sensory attributes of meat.Despite the advent of many novel technologies,aging has not lost its charm and is still widely used commercially as a post-mortem intervention for tenderization.Aging improves the tenderness of meat through disruption of the muscle structure by intracellular proteolytic systems.Muscles undergo various molecular changes that cause proteolysis of key myofibrillar and cytoskeletal proteins,disrupting the overall integrity of muscle cells.Although several endogenous proteolytic systems are capable of post-mortem proteolysis,a great body of scientific evidence supports a major role for the calpain system.Calpains are intracellular calcium-dependent cysteine proteases found in most eukaryotes.At least three calpains(μ-and m-calpains and calpain 3)and calpastatin,their specific endogenous inhibitor,are found in muscle.They are known to be involved in the proteolysis of functionally relevant structural proteins such as the myofibrillar proteins and cytoskeletal anchorage complexes.These ubiquitous proteases are also present in mitochondria and play important roles in a variety of pathophysiological conditions including apoptotic and necrotic cell death phenomena.This review discusses the role and contribution of the calpain system and the factors that influence calpain activity during aging.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
文摘Little is known about changes in calpain activity in the pituitary gland. In the present study,μ- and m-calpain activity changes were detected in the rat anterior pituitary following intraperitoneal injection of diethylstilbestrol. Double-immunofluorescence labeling confirmed colocalization of μ- and m-calpain in prolactin-secreting cells （lactotrophs）. Western blot analysis revealed significantly increased expression of both calpains, which accompanied upregulated cytosol and membrane zymographic activities at 12 weeks following diethylstilbestrol injection, compared with rats injected with sunflower oil. Moreover, following estrogen injection, pituitary gland pathological damage gradually worsened with increasing time. Results demonstrated that estrogen regulated calpain expression and activity, and both calpains participated in the pathophysiological processes of the pituitary gland. Ubiquitous calpain expression could serve as an effective target for anti-estrogen drugs.
基金supported by the Research School in Pharmaceutical Science in Lund,The Royal Physiographic Society in LundThe Swedish Research Council(Medicine)+1 种基金the Craaford’s and Thure Nilsson’s Funds for Medical ResearchFunds for diabetic research,Lund University and Region Skane
文摘Detailed mechanisms behind regeneration after nerve injury, in particular signal transduction and the fate of Schwann cells （SCs）, are poorly understood. Here, we investigated axotomy-induced activation of extracellular- signal-regulated kinase-1/2 （ERK1/2; important for proliferation） and m-calpain in vitro, and the relation to Ca2＋ deletion and Schwann cell proliferation and death after rat sciatic nerve axotomy. Nerve segments were cultured for up to 72 hours with and without ethylene glycol-bis（β-aminoethyl ether）- N,N,N＇,N＇-tetraacetic acid （EGTA）. In some experiments, 5-bromo-2′-deoxyuridine （BrdU） was added during the last 24 hours to detect proliferating cells and propidium iodide （PI） was added at the last hour to detect dead and/or dying cells. Immunohistochemistry of sections of the cultured nerve segments was performed to label m-calpain and the phosphorylated and activated form of ERK1/2. The experiments revealed that immunoreactivity for p-ERK1/2 increased with time in organotypically cultured SCs. p-ERK1/2 and m-calpain were also observed in axons. A significant increase in the number of dead or dying SCs was observed in nerve segments cultured for 24 hours. When deprived of Ca2＋, activation of axonal m-calpain was reduced, whereas p-ERK1/2 was increased in SCs. Ca2＋ deprivation also significantly reduced the number of proliferating SCs, and instead increased the number of dead or dying SCs. Ca2＋ seems to play an important role in activation of ERK1/2 in SCs and in SC survival and proliferation. In addition, extracellular Ca2＋ levels are also required for m-calpain activation and up-regulation in axons. Thus, regulation of Ca2＋ levels is likely to be a useful method to promote SC proliferation.
文摘BACKGROUND： During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin （PRL） and may promote formation of prolactin neoplasia in pituitary anterior lobe. OBJECTIVE： To observe the effect of diethylstilbestrol （DES） on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats. DESIGN： Observational contrast animal study. SETTING： Beijing Neurosurgical Institute. MATERIALS： A total of 21 female Wistar rats, 3 weeks old weighing 70-80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at （24±1）℃ and a humidity of （55±5）%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan. METHODS： The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil （1 mL/kg, twice a week） for 16 weeks; DES group, where animals were administered with DES （5 mg/kg, twice a week） for 16 weeks; DES ＋ vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil （1 mL/kg, twice a week） for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. MAIN OUTCOME MEASURES： ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue. RESULTS： All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination： Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone （ACTH） was increased in both DES group and DES ＋ vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES ＋ vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue： Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissueswere confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES ＋ vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES. CONCLUSION： A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe.
文摘Calpains are ubiquitous non-lysosomal Ca2+-dependent cysteine proteases also present in myocardial cytosol and mitochondria.Numerous experimental studies reveal an essential role of the calpain system in myocardial injury during ischemia,reperfusion and postischemic structural remodelling.The increasing Ca2+-content and Ca2+-overload in myocardial cytosol and mitochondria during ischemia and reperfusion causes an activation of calpains.Upon activation they are able to injure the contractile apparatus and impair the energy production by cleaving structural and functional proteins of myocytes and mitochondria.Besides their causal involvement in acute myocardial dysfunction they are also involved in structural remodelling after myocardial infarction by the generation and release of proapoptotic factors from mitochondria.Calpain inhibition can prevent or attenuate myocardial injury during ischemia,reperfusion,and in later stages of myocardial infarction.
文摘Aging is a popular method used by meat industry for improving the sensory attributes of meat.Despite the advent of many novel technologies,aging has not lost its charm and is still widely used commercially as a post-mortem intervention for tenderization.Aging improves the tenderness of meat through disruption of the muscle structure by intracellular proteolytic systems.Muscles undergo various molecular changes that cause proteolysis of key myofibrillar and cytoskeletal proteins,disrupting the overall integrity of muscle cells.Although several endogenous proteolytic systems are capable of post-mortem proteolysis,a great body of scientific evidence supports a major role for the calpain system.Calpains are intracellular calcium-dependent cysteine proteases found in most eukaryotes.At least three calpains(μ-and m-calpains and calpain 3)and calpastatin,their specific endogenous inhibitor,are found in muscle.They are known to be involved in the proteolysis of functionally relevant structural proteins such as the myofibrillar proteins and cytoskeletal anchorage complexes.These ubiquitous proteases are also present in mitochondria and play important roles in a variety of pathophysiological conditions including apoptotic and necrotic cell death phenomena.This review discusses the role and contribution of the calpain system and the factors that influence calpain activity during aging.
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。
