锰对大鼠睾丸支持细胞骨架蛋白及紧密连接相关蛋白表达的抑制作用

目的研究染锰诱导的大鼠睾丸超微结构改变及支持细胞(vimentin,VM)和紧密连接Occludins、Claudin-11mRNA表达,探讨锰对支持细胞骨架蛋白和紧密连接蛋白的破坏机制。方法雄性SD大鼠随机分为空白对照组,低剂量(15 mg/kg MnCl_2)和高剂量(30 mg/kg MnCl_2)组,8只/组。实验组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,电镜观察睾丸支持细胞及血睾屏障超微结构,免疫组织化学(SABC)法检测支持细胞VM表达,实时定量PCR反应检测血睾屏障紧密连接Occludins和Claudin-11 mRNA表达。结果 1与空白对照组比较,各染锰组支持细胞数量及VM阳性细胞率、Occludins mRNA和Claudin-11 mRNA表达均显著降低。2染锰剂量相同,6周与4周组比较,以及染锰时间相同,高剂量组与低剂量组比较,支持细胞数量及VM阳性细胞率、Occludins mRNA和Claudin-11 mRNA表达均显著降低。3各组大鼠睾丸支持细胞数量与VM阳性细胞率及Occludins mRNA和Claudin-11 mRNA表达均成正相关。结论锰可抑制大鼠睾丸支持细胞骨架蛋白及紧密连接相关蛋白表达,破坏血睾屏障,导致生精微环境改变,产生生殖毒性效应。     

锰诱导大鼠生精细胞凋亡过程中半胱氨酸酶-3mRNA与增殖细胞核抗原表达变化

目的:研究氯化锰对生精细胞凋亡过程半胱氨酸酶3(caspase-3)mRNA和增殖细胞核抗原(PCNA)表达的影响,探讨两者在生精细胞凋亡过程中的作用。方法:雄性SD大鼠随机分为空白对照组、低剂量(15 mg/kg MnCl_2)和高剂量(30mg/kg MnCl_2)组。MnCl_2组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,TUNEL法检测睾丸生精细胞凋亡,原位杂交和免疫组织化学(SABC)检测生精细胞caspase-3 mRNA和PCNA和表达。结果:与空白对照组比较,各染锰组生精细胞凋亡指数(AI)均升高,caspase-3 mRNA阳性细胞率均显著升高,染锰4周:PCNA阳性细胞率显著降低,染锰6周反而升高。染锰剂量相同,6周与4周组比较,生精细胞AI与caspase-3 mRNA阳性细胞率、PCNA阳性细胞率均显著升高。染锰时间相同,高剂量组与低剂量组比较,生精细胞AI与caspase-3 mRNA阳性细胞率均显著升高,PCNA阳性细胞率显著降低。各组大鼠生精细胞AI与caspase-3 mRNA阳性细胞率呈正相关,与PCNA阳性细胞率呈负相关,而caspase-3 mRNA阳性细胞率与PCNA阳性细胞率呈负相关。结论:锰可诱导大鼠生精细胞caspase-3mRNA表达,促使生精细胞凋亡并且抑制细胞增殖,产生生殖毒性效应。     

细胞色素C和波形蛋白在染锰大鼠睾丸表达及对精子发生的抑制作用

目的研究氯化锰对大鼠生精细胞细胞色素C(cyto-c)和支持细胞波形蛋白(VM)表达的影响及对生精功能的抑制效应。方法雄性SD大鼠随机分为空白对照组,低剂量(15 mg/kg Mn Cl2)和高剂量(30 mg/kg Mn Cl2)组,8只/组。Mn Cl2组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,取睾丸免疫组织化学(SABC)法检测生精细胞cyto-c和VM表达,测定睾丸脏器系数,取附睾检测精子数量和精子畸形率。结果与空白对照组比较,各染锰组生精细胞cyto-c阳性细胞率和支持细胞VM阳性细胞率及各生精功能指标均显著降低,并呈一定的时间-效应关系和剂量-效应关系。各组大鼠精子数量与cyto-c阳性细胞率和VM阳性细胞率均呈正相关。结论锰可诱导大鼠生精细胞cyto-c和支持细胞VM表达,抑制生精细胞增殖,产生生殖毒性效应。     

染锰大鼠生精细胞凋亡中caspase-3 mRNA、凋亡蛋白酶活化因子-1及多聚ADP核糖聚合酶的表达变化

目的:研究染锰诱导的大鼠生精细胞凋亡过程中,天冬氨酸特异性半胱氨酸酶-3(caspase-3)mRNA和凋亡蛋白酶活化因子-1(Apaf-1)、多聚ADP核糖聚合酶(PARP)的表达及其关系,探讨它们在生精细胞凋亡过程中的作用。方法:雄性SD大鼠,设立空白对照组、低剂量(15 mg/kg MnCl_2)和高剂量(30 mg/kg MnCl_2)组。实验组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,TUNEL法检测生精细胞凋亡,原位杂交法和免疫组织化学法检测生精细胞caspase-3 mRNA、Apaf-1和PARP的表达。结果:与空白对照组比较,各染锰组生精细胞凋亡指数(AI)和caspase-3mRNA阳性细胞率均显著升高,Apaf-1和PARP阳性细胞率均显著降低。染锰剂量相同,6周与4周组比较,以及染锰时间相同,高剂量组与低剂量组比较,生精细胞AI和caspase-3 mRNA阳性细胞率均显著升高,Apaf-1和PARP阳性细胞率均显著降低。各组大鼠生精细胞AI与caspase-3 mRNA阳性细胞率呈正相关,与Apaf-1和PARP阳性细胞率呈负相关。结论:锰可影响大鼠生精细胞caspase-3 mRNA表达,促进Apaf-1和PARP分解,导致生精细胞凋亡,产生生殖毒性效应。     

染锰大鼠生精细胞半胱氨酸蛋白酶3的表达及锌的保护作用

目的:研究氯化锰对生精细胞半胱氨酸蛋白酶3(caspase-3)表达的影响,探讨锰诱发大鼠生精细胞caspase-3表达的机制及锌的拮抗作用.方法:雄性SD大鼠随机分为空白对照组,ZnCl_2对照组,15mg/kg和30mg/kg MnCl_2组;15mg/kg和30mg/kg MnCl_2+ZnCl_2组.免疫组织化学法检测睾丸caspase-3表达.结果:各染锰组,染锰补锌组及染锰剂量相同的6周组,染锰时间相同的30mg/kg MnCl_2组caspase-3阳性细胞率均显著升高,染锰补锌组显著降低.结论:染锰15mg/kg 4周可诱发大鼠生精细胞caspase-3表达,且随染锰时间和剂量的增加而增加,两者存在一定时间-效应和剂量-效应关系;摄入含锌100mg/kg的食物可拮抗锰诱发的生精细胞caspase-3表达.     

Caspase-3mRNA与PARP在染锰大鼠生精细胞中表达变化

目的研究氯化锰对生精细胞凋亡过程半胱氨酸酶3(caspase-3)mRNA和多聚ADP核糖聚合酶(PARP)表达的影响,探讨氯化锰的生殖毒性效应及可能机制。方法雄性SD大鼠48只随机分为空白对照组,低剂量(15 mg/kg MnCl_2)和高剂量(30 mg/kg MnCl_2)组,8只/组。MnCl_2组分别染锰4周和6周,空白对照组给予等容生理盐水,给药途径均为腹腔注射,TUNEL法检测睾丸生精细胞凋亡,原位杂交法和免疫组织化学(SABC)法检测生精细胞caspase-3mRNA和PARP和表达。结果随染锰时间延长和剂量增加,各染锰组生精细胞凋亡指数(AI)及caspase-3 mRNA表达水平显著升高,PARP表达水平显著降低,凋亡指数AI分别与caspase-3 mRNA和PARP表达呈正相关和负相关。结论锰可诱导大鼠生精细胞caspase-3 mRNA表达,促进PARP分解,导致生精细胞凋亡,产生生殖毒性效应。     

锰对大鼠生精细胞Caspase-3 mRNA调控及支持细胞波形蛋白表达的影响

目的 探讨锰对大鼠生精细胞Caspase-3 mRNA调控及支持细胞波形蛋白（vimentin）表达的影响。 方法 将正常雄性SD大鼠48只,随机分为1个对照组和2个染锰组,给予各组大鼠腹腔注射生理盐水和15mg/kg、30mg/kg氯化锰。分别染锰4周和6周,随机处死各组大鼠8只。应用末端脱氧核糖核酸转移酶介导的dUTP缺口末端标记技术（TUNEL） 、原位杂交法和免疫组织化学链酶亲和素生物素过氧化物酶复合物（SABC）法进行检测研究。 结果 1. 与空白对照组比较,15mg/kg、30mg/kg染锰组生精细胞凋亡指数（AI）均升高（ P<0.05, P<0.01）,Caspase-3 mRNA阳性细胞率均显著升高（ P<0.01）,支持细胞波形蛋白（vimentin）阳性细胞率均显著降低（ P<0.01）。2. 染锰剂量相同,染锰6周组与染锰4周组比较,生精细胞AI与Caspase-3 mRNA阳性细胞率均显著升高（ P<0.01）,支持细胞vimentin阳性细胞率均显著降低（ P<0.01）。3. 染锰时间相同,30mg/kg MnCl2组与15mg/kg MnCl2组比较,生精细胞AI与Caspase-3 mRNA阳性细胞率均显著升高（ P<0.01）,支持细胞vimentin阳性细胞率均显著降低（ P<0.01）。4. 各组大鼠生精细胞AI和Caspase-3 mRNA阳性细胞率呈正相关（ r =0.842, P<0.01）,与支持细胞vimentin阳性细胞率呈负相关（ r =-0.859, P<0.01）,各组大鼠生精细胞Caspase-3 mRNA阳性细胞率和支持细胞vimentin阳性细胞率呈负相关（ r =-0.975, P<0.01）。 结论 染锰大鼠生精细胞Caspase-3 mRNA表达增加导致生精细胞凋亡增加;支持细胞vimentin表达下降;这可能是锰生殖毒性的重要分子机制之一。     

镉对大鼠血睾屏障的损伤及黄芪甲苷的保护作用

目的观察黄芪甲苷和SB203580对镉致大鼠血睾屏障破坏及相关蛋白表达改变的保护效应,探讨黄芪甲苷的保护机制。方法 21只成年雄性SD大鼠随机分为7组:单纯镉组[0.1%氯化镉腹腔内注射,1mg/(kg·d)],镉+黄芪甲苷组[镉剂量同上,同时注射黄芪甲苷,10mg/(kg·d)],镉+SB203580组[镉剂量同上,同时注射SB203580,100μg/(kg·d)],以上各组又分为连续处理5d和10d两个时间组,对照组腹腔内注射等量生理盐水。各实验和对照组动物均为3只。取睾丸做光学显微镜、电子显微镜观察以及免疫组织化学染色和Western blotting检测。结果 HE染色观察对照组支持细胞核染色较浅且不规则,镉组支持细胞内有空泡形成,镉+黄芪甲苷组与镉+SB203580组未见明显形态异常。免疫组织化学染色观察对照组闭锁小带-1蛋白(ZO-1)、紧密连接蛋白-11(claudin-11)阳性产物在生精上皮靠近基底部表达。镉组ZO-1、claudin-11阳性产物表达均显著降低(P0.05),镉+黄芪甲苷组与镉+SB203580组阳性产物表达低于对照组但明显高于镉组(P0.05)。超微结构观察对照组血睾屏障紧密连接形态完整,呈连续的电子密度较深致密线,镉组血睾屏障紧密连接及支持细胞均见不同程度破坏,镉+黄芪甲苷组与镉+SB203580组破坏程度较相应处理时间镉组为轻。Western blotting结果显示,镉组磷酸化p38丝裂原活化蛋白激酶(p-p38MAPK)水平明显增强(P0.05),镉+黄芪甲苷组与镉+SB203580组pp38MAPK水平虽高于对照组,但较镉组明显减弱(P0.05)。结论镉致大鼠血睾屏障ZO-1、claudin-11表达降低,紧密连接超微结构损伤,黄芪甲苷具有保护作用,其保护机制与抑制p38MAPK磷酸化有关。     

谷胱甘肽对染锰大鼠生精细胞凋亡与增殖的影响

目的:研究谷胱甘肽(GSH)对染锰大鼠生精细胞凋亡与增殖的作用及机制。方法:雄性SD大鼠48只随机分为6组,各组给锰途径为腹腔注射。采用TUNEL法检测生精细胞凋亡指数(AI);免疫组织化学法检测生精细胞增殖细胞核抗原(PCNA)表达。结果:与空白对照组比较,GSH对照组和15mg/kg GSH组生精细胞AI与生精细胞PCNA增殖指数(PI)均无显著性差异;与各自对应的单纯染锰组比较,15mg/kg GSH组和30mg/kg GSH组生精细胞AI均显著降低而PI均显著升高;30mg/kg组与15mg/kg组比较,生精细胞AI显著升高而PI显著降低;各组大鼠生精细胞AI和PI呈负相关。结论:15mg/kg和30mg/kg氯化锰可诱发大鼠睾丸生精细胞凋亡,两者存在剂量-效应关系;各组大鼠睾丸生精细胞AI和PI呈显著负相关;GSH对锰诱发大鼠生精细胞凋亡具有拮抗作用;GSH可能拮抗锰对大鼠生精细胞增殖的抑制作用。     

胱抑素C对脑缺血再灌注损伤大鼠大脑皮质紧密连接的影响

目的:观察胱抑素C(Cys C)干预对脑缺血再灌注损伤(IRI)后大鼠脑皮质毛细血管内皮细胞紧密连接超微结构的形态学变化并探讨其影响机制。方法:雄性SD大鼠随机分为假手术组(Sham)、缺血再灌注损伤组(IRI)和胱抑素C(Cys C)干预组(根据药物浓度不同分为低、中、高3个亚组分别为Cys C-L、Cys C-M和Cys C-H),采用改良线拴法建立大鼠大脑中动脉缺血2 h再灌注24 h模型。透射电镜下观察内皮细胞紧密连接超微结构的改变,Western Blot观察损伤侧脑皮质ZO-1蛋白表达变化,免疫荧光检测Hsp20的表达与分布。结果:与Sham组相比,IRI组电镜下可见毛细血管内皮细胞紧密连接开放,ZO-1蛋白表达明显减少(P 0. 01),Hsp20细胞数目增多。与IRI组比较,Cys C-L、Cys C-M组紧密连接开放程度明显减轻,ZO-1蛋白表达增加(P 0. 01),Hsp20阳性细胞数也显著增多。而Cys C-H组紧密连接结构消失,毛细血管内皮细胞间完全开放、松散;ZO-1蛋白表达明显降低,Hsp20阳性细胞数也明显减少。结论:Cys C在一定浓度下干预能减轻脑IRI对紧密连接超微结构的破坏,其机制可能与ZO-1蛋白表达增加及Hsp20阳性细胞个数增多有一定的关系。     

雷公藤甲素抗肿瘤血管新生的研究进展（英文）

雷公藤甲素(triptolide,TPL)是从中草药雷公藤中提取的一种有效活性物质,已被用来治疗多种疾病,包括系统性红斑狼疮,类风湿性关节炎,肾病综合征等,TPL甚至有很强的抑制肿瘤的活性。近些年的研究显示,TPL具有抗血管新生的能力,TPL不仅可以抑制肿瘤的增殖,诱导细胞的凋亡,还可以抑制肿瘤的转移,可以增加其它化疗药物的抗肿瘤活性。本综述将讨论TPL在抗肿瘤血管新生方面的研究进展,以及初步探讨其潜在的作用机制。     

Changes in activity of neutral proteases in tissues of ground squirrels in the dynamics of hibernation

Total activities of neutral proteases in the cerebral, hepatic, and myocardial tissues of ground squirrel vary during hibernation: in autumn (before hibernation) activities of the enzymes in the brain and myocardium start increasing, while in the liver they do not change. A common feature for all tissues is minimum activity of active neutral proteases in the middle of hibernation month 1 bout, while the maximum activity is recorded before awakening. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 9, pp. 278–280, September, 2008     

Kinetics of decline of maternal measles virus-neutralizing antibodies in sera of infants in France in 2006

The optimal age for measles vaccination is an important health issue, since maternal antibodies may neutralize the vaccine antigen before a specific immune response develops, while delaying vaccination may increase the risk of complicated diseases in infants. However, measles vaccination impacts the duration of protection afforded by transplacental transfer of maternal antibodies: vaccination-induced maternal antibodies disappear faster than disease-induced antibodies. In order to maintain protection against measles in infants, it is important to monitor the dynamics of this phenomenon in vaccinated populations. To assess the current situation in France, a multicenter, prospective seroepidemiological study was conducted in seven French hospitals between October 2005 and January 2007. Maternal measles antibody concentrations from 348 infants 0 to 15 months old were measured using the plaque reduction neutralization assay. Geometric mean concentrations and the percentage of infants with maternal measles antibody concentrations above the protection threshold (≥120 mIU/ml) were assessed according to age. Results show that after more than 20 years of routine measles vaccination in France, maternal measles-neutralizing antibodies decrease dramatically in French infants by 6 months of age, from 1,740 mIU/ml for infants 0 to 1 month old to 223 mIU/ml for infants 5 to 6 months old, and that 90% of infants are not protected against measles after 6 months of age. Infant protection against measles could be optimized both by increasing herd immunity through an increased vaccine coverage and by lowering the age of routine vaccination from 12 to 9 months.     

Effect of vitamin C in reducing the toxicity of endosulfan in liver in rabbits

In this study, the effect of endosulfan, an organochlorine pesticide, and the ameliorating effect of vitamin C on the livers of New Zealand white rabbits were studied. Livers of the rabbits were examined grossly and histopathologically, and caspase-3 activity was detected by immunohistochemical methods. A total of twenty-four rabbits were divided into four groups (n=6). Rabbits in Group I (END) were daily given a sublethal dose of endosulfan (1 mg/kg bw) in corn oil by oral gavage for 6 weeks. Group II (END+C) received the same dose of endosulfan and additionally Vit C (20 mg/kg bw) every other day during this period. Group III (OIL+C) received corn oil daily by oral gavage and vitamin C every other day for 6 weeks. Group IV (OIL), the control group, received only corn oil daily, by oral gavage throughout the experiment. The concentration of α-endosulfan in the END group was higher in livers (0.102±0.012 ppb) than the β-endosulfan (0.072±0.001 ppb). Decreased accumulation of α and β endosulfan was observed in the END+C group (0.025±0.003 and 0.016±0.002 ppb, respectively) (p<0.0001). The most prominent gross findings at the necropsy were seen in the END group, in which swollen and pale livers were commonly observed. Hemorrhages, degenerations, necrosis, and in some rabbits bile duct hyperplasia were the marked histopathological findings of the END group. Caspase-3 positive reaction was more severe in this group than in the others. An ameliorating effect of Vit C on gross, histopathological and immunohistochemical findings was observed in the END+C group. The results revealed that endosulfan is highly toxic for rabbit livers. However, toxicity was decreased by Vit C treatment, which reduced the accumulation of endosulfan in livers four-fold.