PI3K-Akt-eNOS信号转导通路在七氟醚后处理减轻大鼠心肌缺血再灌注损伤中的作用

目的 评价磷酯酰肌醇-3-激酶/丝氨酸-苏氨酸激酶/内皮型一氧化氮合酶(PI3K-Akt-eNOS)信号转导通路在七氟醚后处理减轻大鼠心肌缺血再灌注损伤中的作用.方法 健康雄性Wistar大鼠50只,体重250 ～ 280 g,2～3月龄,采用随机数字表法,将大鼠随机分为5组(n=10):假手术组(S组)、缺血再灌注组(I/R组)、七氟醚后处理组(Spo组)、七氟醚后处理+二甲基亚砜组(Spo+D组)和七氟醚后处理+ PI3K特异性抑制剂LY294002组(Spo+L组).I/R组、Spo组、Spo+D组和Spo+L组采用结扎左冠状动脉前降支30 min的方法制备心肌缺血再灌注损伤模型.Spo组、Spo+D组和Spo+L组进行七氟醚后处理:再灌注前1 min使呼气末七氟醚浓度达到2.5％～3.0％,持续吸入5min; Spo+L组于再灌注前5min静脉注射LY294002 0.3 mg/kg,Spo+D组给予等容量二甲基亚砜.再灌注120 min时,每组取10只大鼠,采集动脉血样,检测血清LDH、CK-MB的活性和cTnI浓度.每组处死5只大鼠,取心脏,分离左心室,计算心肌梗死体积;每组处死5只大鼠,取心肌组织,测定Akt、磷酸化Akt(p-Akt)、eNOS和磷酸化eNOS(p- eNOS)的表达,计算p-Akt表达与Akt表达的比值(p-Akt/Akt)和p-eNOS表达与eNOS表达的比值(p-eNOS/eNOS).结果 与S组比较,其余4组血清CK-MB、LDH的活性、cTnI浓度、心肌梗死体积升高,心肌p-Akt/Akt和p-eNOS/eNOS升高(P＜0.05或0.01);与I/R组比较,Spo组和Spo+D组血清CK-MB、LDH的活性、cTnI浓度和心肌梗死体积降低,心肌p-Akt/Akt和p-eNOS/eNOS升高(P＜0.05或0.01),Spo+L组上述指标差异无统计学意义(P＞0.05);Spo组与Spo+D组上述指标比较差异无统计学意义(P＞0.05).结论 PI3K-Akt-eNOS信号转导通路介导了七氟醚后处理减轻大鼠心肌缺血再灌注损伤作用.     

远端缺血后处理对大鼠全脑缺血再灌注损伤的影响

目的 探讨远端缺血后处理对大鼠全脑缺血再灌注损伤的影响.方法 健康成年雄性SD大鼠128只,体重为200～ 250 g,采用随机数字表法,将其随机分为4组(n=32):假手术组(S组)、缺血再灌注组(I/R组)、I/R+远端缺血后处理组(I/R+ RIPoC组)以及远端缺血再灌注组(RI/R组).采用改良的Pulsinelli四动脉阻断法建立大鼠全脑缺血再灌注模型.S组不制备全脑缺血再灌注模型;I/R+ RIPoC组于再灌注开始行双侧股动脉缺血15 min,再灌注15 min,共计3个循环;RI/R组仅行双侧股动脉缺血15 min,再灌注15 min,共计3个循环.于再灌注24、48 h时取脑组织,行海马CA1区和额叶皮层凋亡细胞计数,测定海马CA1区Bcl-2和Bax的表达水平,并于再灌注48 h测定超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性及丙二醛(MDA)的含量;再灌注4d时行Morris水迷宫实验;再灌注7d时取脑组织,计算海马CA1区和额叶皮层神经元密度.结果 与S组比较,I/R组再灌注时凋亡细胞计数升高,Bcl-2和Bax表达上调,神经元密度、SOD和CAT活性降低,MDA含量升高,逃避潜伏期明显延长,穿越原平台次数与第2象限停留时间百分比降低(P≤0.Ol),RI/R组上述指标差异无统计学意义(P＞0.05);与I/R组比较,I/R+ RIPoC组再灌注时凋亡细胞计数降低,Bcl-2表达上调,Bax表达下调,神经元密度、SOD和CAT活性升高,MDA含量降低,逃避潜伏期缩短,穿越原平台次数与第2象限停留时间百分比升高(P＜0.01).结论 远端缺血后处理可减轻大鼠全脑缺血再灌注损伤,其机制与抑制脂质过氧化反应,调节Bcl-2与Bax的平衡抑制细胞凋亡有关.     

一氧化氮在吗啡后处理抑制大鼠缺血再灌注心肌细胞凋亡中的作用

目的 探讨一氧化氮在吗啡后处理抑制大鼠缺血再灌注损伤心肌细胞凋亡中的作用.方法 清洁级雄性SD大鼠60只,体重280～330 g,随机分为4组(n=15):假手术组(S组)只穿线不结扎;缺血再灌注组(I/R组)结扎左冠状动脉前降支45 min,再灌注120 min;吗啡后处理组(M组)再灌注前3 min至再灌注2 min经左颈内静脉注射吗啡1.25 mg/kg;L-NAME+吗啡后处理组(L+M组)左冠状动脉前降支结扎前20 min静脉注射L-NAME 10 mg/kg.分别于缺血前、缺血20 min及再灌注120 min时监测心率(HR)和平均动脉压(MAP),并计算HR与收缩压(SP)的乘积(RPP);于再灌注120 min时取心肌,采用TUNEL法检测心肌凋亡细胞,计算心肌细胞凋亡指数(AI),采用Western blot法检测总内皮型一氧化氮合酶(eNOS)和磷酸化eNOS蛋白的表达水平,计算磷酸化eNOS蛋白表达与总eNOS蛋白表达的比值(p-eNOS/eNOS),硝酸盐还原酶法测定心肌NO含量.结果 I/R组、M组及L+M组间各时点HR、MAP及RPP差异无统计学意义(P>0.05);与S组比较,其余各组AI升高,I/R组和L+M组心肌NO含量降低,M组升高(P<0.05);与I/R组比较,M组AI降低,M组心肌NO含量升高(P<0.05),L+M组差异无统计学意义(P>0.05),M组和L+M组p-eNOS/eNOS升高(P<0.05);与M组比较,L+M组AI升高,心肌NO含量降低(P<0.05),p-eNOS/eNOS差异无统计学意义(P>0.05).结论 吗啡后处理可通过激活eNOS促进NO产生,抑制大鼠缺血再灌注损伤诱发的心肌细胞凋亡.     

ROS和PI3K-Akt在缺血后处理或控制性低压灌注减轻大鼠脊髓缺血再灌注损伤中的作用

目的 探讨活性氧自由基(ROS)和磷酸酰肌醇3激酶-蛋白激酶B(PI3K-Akt)在缺血后处理或控制性低压灌注减轻大鼠脊髓缺血再灌注损伤中的作用.方法 雄性SD大鼠126只,体重300～350 g,随机分为7组(n=18),缺血再灌注组(I/R组)阻断胸主动脉同时维持MAP40 mm Hg持续9 min进行脊髓缺血,胸主动脉开放后使MAP升至100 mm Hg进行脊髓再灌注;缺血后处理组(IP组)开放主动脉后,进行再灌注30 s缺血30 s,重复3次,同时维持MAP 100 mm Hg;控制性低压灌注组(LR)开放主动脉后维持MAP 40 mm Hg持续5 min后升高至100 mm Hg;缺血后处理+PI3K抑制剂LY-294002组(IP+L组)和控制性低压灌注+LY-294002组(LR+L组)分别于实施缺血后处理和控制性低压后立即动脉注射LY-294002 25 mg/kg;缺血后处理+氧自由基清除剂N-乙酰半胱氨酸组(IP+N组)和控制性低压灌注+N-乙酰半胱氨组(LR+N组)分别于实施缺血后处理和控制性低血压后立即动脉注射N-乙酰半胱氨酸100 mg/kg.于再灌注2 h时,各组处死12只大鼠,取腰段脊髓组织,测定胞浆Akt磷酸化水平和线粒体通透性转换孔(mPTP)开放程度.分别于再灌注4、12、24、48 h进行神经行为学评分,然后处死大鼠,取腰段脊髓组织,分别进行脊髓前角正常神经元和凋亡神经元的计数.结果 与I/R组比较,IP组和LR组Akt磷酸化水平升高,mPTP开放程度和神经元凋亡计数降低,神经行为学评分和正常神经元计数升高(P＜0.01);IP组与LR组各指标比较差异无统计学意义(P＞0.05).LY294002和N-乙酰半胱氨酸均可逆转缺血后处理和控制性低压灌注对脊髓的保护作用,引起mPTP开放程度升高(P＜0.01).结论 ROS激活PI3K-Akt进而降低线粒体通透性是缺血后处理或控制性低压灌注减轻大鼠脊髓缺血再灌注损伤的机制.     

上调miRNA-133a表达对心肌缺血再灌注损伤的保护作用

目的 观察上调miRNA-133a表达是否可改善缺血再灌注损伤后心肌损害及心脏功能.方法 建立活体大鼠心肌缺血再灌注损伤模型.将实验动物随机分为5组:(1)空白对照组(Sham组);(2)缺血再灌注损伤组(I/R组);(3)缺血再灌注损伤+miRNA-133a模拟物agomiR-133a组(I/R+ agomiR-133a组);(4)缺血再灌注损伤+阴性对照序列组(I/R+ scramble组);(5)缺血再灌注损伤组+生理盐水组(I/R+ NS组).于再灌注24h分别使用实时定量聚合酶链反应(Real-TimePCR)法检查心肌内miRNA-133a表达水平;经胸超声心动检查大鼠心脏功能;2,3,5-氯化三苯基四氮唑(TTC)染色检测心肌梗死以及TdT介导的dUTP缺口末端标记(TUNEL)检测心肌细胞凋亡.结果 I/R+ agomiR-133a组心肌内miRNA表达水平显著高于I/R组(P＜0.01).上调miRNA-133a表达水平可显著减少再灌注后心肌梗死面积[(37.0±3.1)％比(58.0±4.4)％,P＜0.01],抑制心肌细胞凋亡(38.4±6.0比15.7±5.2,P＜0.01),并改善心脏功能[LVEF:(64.8 ±2.9)％比(52.8±4.0)％,LVFS:(31.1±1.2)％比(25.2±0.8)％,P＜0.01].NS与scramble对再灌注后心肌损伤及心脏功能无显著影响.结论 上调心肌内miRNA-133a表达水平可显著减轻缺血再灌注损伤24h后心肌损害,并改善心脏功能.     

乳化异氟醚预处理对大鼠局灶性脑缺血再灌注时海马CA1区神经元凋亡的影响

目的 评价乳化异氟醚预处理对大鼠局灶性脑缺血再灌注时海马CA1区神经元凋亡的影响.方法 健康成年雄性SD大鼠48只,体重250～300 g,月龄4～6月,采用随机数字表法,将大鼠随机分为6组(n=8),假手术组(S组)腹腔注射生理盐水10.5 ml/kg,24 h后只分离血管,不置入线栓;缺血再灌注组(I/R组)和乳化异氟醚预处理组(EI组)分别腹腔注射生理盐水或8%乳化异氟醚10.5 ml/kg(120 mg/ml);LY294002+乳化异氟醚预处理组(L+EI组)缺血侧侧脑室注射LY294002(磷脂酰肌醇-3激酶特异性抑制剂)25 mmol/L 5 μl,30 min后腹腔注射8%乳化异氟醚10.5 ml/kg;LY294002组(L组)和DMSO(LY294002溶剂)组缺血侧侧脑室注射LY294002 25 mmol/L(5 μl)或DMSO 5 μl.于给 药后24 h采用大脑中动脉缺血2 h恢复再灌注的方法制备局灶性脑缺血再灌注模型.于再灌注24 h时行神经功能缺陷评分,检测海马CA1区神经元凋亡情况和磷酸化丝氨酸-苏氨酸蛋白激酶(p-Akt)表达,观察海马CA1区病理学改变.结果 与S组比较,其余各组神经功能缺陷评分、凋亡细胞计数升高.p-Akt表达上调(P＜0.05);与I/R组比较,EI组神经功能缺陷评分、凋亡细胞计数降低,p-Akt表达上调(P＜0.05),L+EI组、L组、DMSO组上述各指标差异无统计学意义(P＞0.05);与EI组比较,L+EI组神经功能缺陷评分、凋亡细胞计数升高,p-Akt表达下调(P＜0.05).EI组病理学损伤程度明显轻于I/R组,L+EI组、L组、DMSO组与I/R组相似.结论 乳化异氟醚预处理可减少大鼠局灶性脑缺血再灌注时海马CA1区神经元凋亡,其神经元保护作用与PI3K/Akt通路激活有关.

Abstract：

Objective To investigate the effect of preconditioning with emulsified isoflurane (eISO) on neuronal apoptosis in hippocampal CA1 region induced by focal cerebral ischemia-reperfusion (I/R) injury in rats. Methods Forty-eight healthy adult male SD rats weighing 250-300 g were randomly divided into 6 groups (n = 8 each): sham operation group (group S); I/R group; eISO + I/R group (group EI); LY294002 (a specific PI3K inhibitor) + eISO + I/R group (group L+ EI); LY294002 + I/R group (group L) and DMSO (solvent for LY294002) + I/R group (group DMSO). Focal cerebral I/R was induced by 2 h middle cerebral artery occlusion ( MCAO). A nylon thread (0.26 mm in diameter) with rounded tip was inserted into internal carotid artery and advanced cranially until resistance was met (depth of insertion about 18-20 mm) . eISO 10.5 ml/kg (120 mg/ml) was injected intraperitoneally (IP) in groups EI and L+ EI. LY294002 (25 mmol/L) 5 pi was injected into cerebral ventricle on the ischemic side in group L + EI ( at 30 min before eISO) and group L. DMSO 5 μl was injected into the cerebral ventricle on ischemic side before MCAO in group DMSO. Neurologic deficit was assessed and scored (0 = normal, 4 = unconscious) at 24 h of reperfusion. The animals were then killed and their brains were removed for detection of neuronal apoptosis (by TUNEL) and p-Akt expression (by immuno-histochemistry) in hippocampal CA1 region. Results Cerebral I/R significantly increased the neurologic deficit scores, the number of apoptotic cells and p-Akt expression in group I/R as compared with group S. Preconditioning with elSO attenuated the I/R-induced increase in neurologic deficit scores and number of apoptotic cells but further increased p-Akt expression. The neuroprotective effect of eISO preconditioning against I/R-induced changes was counteracted by LY294002. Conclusion eISO preconditioning can attenuate focal cerebral I/R-induced neuronal apoptosis in rats by activating PI3K/Akt pathway.     

磷脂酰肌醇-3-激酶/丝氨酸苏氨酸蛋白激酶/内皮型一氧化氮合酶信号通路在二氮嗪后处理缺血/再灌注大鼠心肌中的作用

目的 研究磷脂酰肌醇-3-激酶/丝氨酸苏氨酸蛋白激酶/内皮型一氧化氮合酶(phosphatidylinositol-3-kinase/protein serine threonine kinase/endothelial nitric oxide synthase,PI3K/Akt/eNOS)信号通路在二氮嚷后处理大鼠在体心肌缺血/再灌注(ischemia/reperfusion,I/R)损伤中的作用. 方法 40只雄性SD大鼠完全随机分为5组,每组8只:假手术组(S组)、I/R组、二氮嗪组(D组)、PI3K抑制剂渥蔓菁霉素组(W组)和二氮嗪+渥蔓菁霉素组(DW组).结扎左冠状动脉前降支30 min、再开放120 min,建立在体心肌I/R损伤模型,S组不结扎.再灌注5 min前,5组依次分别经股静脉输入0.1％二甲基亚砜(dimethyl sulfoxide,DMSO)1 ml/kg、0.1％ DMSO 1 ml/kg、二氮嗪7 mg/kg、渥蔓菁霉素15 μg/kg,DW组于输入二氮嗪前5 min输入渥蔓菁霉素;所有药物均输注15 min.再灌注末,测定血浆心肌肌钙蛋白I(cardiac troponin I,cTnI)浓度,苏木精-伊红(HE)染色观察心肌病理变化,免疫组化分析eNOS的表达情况. 结果 与S组比较,其余4组cTnI显著增高(P＜0.01),心肌明显损伤,eNOS表达增高(P＜0.05或P＜0.01).与I/R组比较,D组和DW组cTnI[(36.5±5.2) μg/L与(44.5±4.5)μg/L vs (64.7±11.1) μg/L]明显降低(P＜0.01),心肌病理改变减轻,eNOS表达增高[(0.515±0.136)％与(0.394±0.100)％ vs (0.241±0.077)％](P＜0.01).与D组比较,DW组cTnI明显增高[(44.5±4.5) μg/L vs (36.5±5.2) μg/L] (P＜0.05),心肌损伤加重,eNOS表达降低[(0.394±0.100)％ vs (0.515±0.136)％] (P＜0.01). 结论 二氮嗪后处理减轻大鼠心肌I/损伤的作用部分与PI3K/Akt/eNOS信号通路激活有关.     

线粒体ATP敏感性钾通道阻断剂对在体大鼠肺缺血后处理的作用及其机制

目的 探讨缺血后处理(IPO)对大鼠在体肺缺血-再灌注损伤(I/R)的保护作用及线粒体ATP敏感性钾通道(mitoKATP)在缺血后处理效应中的作用.方法 将Wistar大鼠35只随机分为5组:假手术组(Sham组)、缺血再灌注损伤组(I/R组)、缺血后处理组(IPO组)、缺血再灌注损伤+5-羟基葵酸盐组(I/R+5-HD组)、缺血后处理+5-羟基葵酸盐组(IPO+5-HD组).观察各组肺组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、湿/干比值(W/D)以及病理形态学改变.结果 I/R组与Sham组比较MDA含量增加[(5.07±1.60)nmol/mg prot比(1.43±0.41)nmol/mgprot,P＜0.01],SOD活性减低[(12.38±2.24)U/mg prot比(45.51±5.42)U/mg prot,P＜0.01],W/D比值增高(5.45±0.82比3.05±0.47,P＜0.01),肺组织形态及超微结构明显受损;IPO+5-HD组与IPO组比较MDA含量增加[(3.74±0.71)nmol/mg prot比(2.60±0.43)nmol/mg prot,P＜0.01],SOD活性减低[(22.91±2.71)U/mg prot比(28.74±2.03)U/mg prot,P＜0.01],W/D比值增高(4.64±0.79比3.89±0.60,P＜0.01),肺组织形态及超微结构明显受损;IPO组与I/R组比较,肺组织MDA含量减少[(2.60±0.43)nmol/mg prot比(5.07±1.60)nmol/mg prot,P＜0.01],SOD活性增高[(28.74±2.03)U/mg prot比(12.38±2.24)U/mg prot,P＜0.01],W/D比值减低(3.89±0.60比5.45±0.82,P＜0.01),肺组织病理形态学改变轻于I/R组;I/R+5-HD组与I/R组比较,肺组织MDA含量[(5.14±1.30)mol/mg prot比(5.07±1.60)mol/mg prot,P＞0.05)、SOD活性[(11.65±1.82)U/mg prot比(12.38±2.24)U/mg prot,P＞0.05]、W/D比变化(5.54±0.61比5.45±0.82),差异无统计学意义(P＞0.05),肺组织病理形态学改变无明显差异.IPO+5-HD组的各项指标介于IPO组和I/R组之间.结论 缺血后处理能减轻大鼠在体肺缺血再灌注损伤,mitoKATP参与了肺缺血后处理效应.

Abstract：

Objective To investigate the protective effect of ischemic postconditioning (IPO) on lung ischemic reperfusion (L/R) in rats in vivo and the mechanism of mitochondrial ATP-sensitive potassium channel (mitoKATP) blocker in the ischemic postconditioning. Methods Thirty five Wistar rats were randomly divided into 5 groups: sham group, I/R group, ischemic postconditioning (IPO) group, I/R +5-hydroxydecanoate (I/R + 5-HD) group, IPO + 5-HD group. The concentration of malondialdehyde (MDA) and activity of superoide dismutase (SOD) were determined in the lung homogenate, wet to dry weight ratio (W/D) was measured and pathological changes were also observed. Results The levels of MDA[(5.07±1.60) vs (1.43 ±0.41) nmol/mg prot,P＜0. 01]and W/D (5.45 ±0.82 vs 3.05 ±0. 47,P ＜0. 01 ) were increased significantly in I/R group as compared with sham group, while the activity of SOD[( 12. 38 ±2. 24) vs (45.51 ±5.42) U/mg prot,P ＜0. 01]was decreased, and the injury of lung tissues was significantly aggravated in IPO + 5-HD group as compared with IPO group[MDA: (3.74 ±0. 71 ) nmol/mg prot vs (2. 60 ± 0. 43 ) nmol/mg prot , P ＜ 0. 01]; W/D: 4. 64 ± 0. 79 vs 3. 89 ± 0. 60,P＜0.01; SOD:[(22.91 ±2.71) U/mg prot vs (28.74±2.03) U/mg prot,P＜0. 01]. The levels of MDA[(2.60±0.43) vs (5.07 ±1.60) nmol/mg prot,P＜0. 01]and W/D (3.89 ±0.60 vs 5.45 ±0. 82,P ＜0. 01 ) were decreased significantly in IPO group as compared with I/R group, the activity of SOD[(28.74±2.03) vs (12.38 ±2.24) U/mg prot,P＜0. 01]increased and lung tissue histological damage attenuated. The difference in MDA[(5.14 ± 1.30) vs (5.07 ± 1.60) nmol/mg prot, P ＞ 0. 05],W/D (5.54±0.61 vs5.45 ±0.82,P＞0.05) and SOD[(11.65 ±1.82) vs (12.38 ±2.24) U/mgprot,P ＞ 0. 05]levels had no statistical significance between I/R + 5-HD group and I/R group, and the injury of lung tissues had no significant difference too. Each index in IPO + 5-HD group was between IPO and I/R groups. Conclusion Ischemic postconditioning can attenuate the lung I/R injury, and mitoKATP plays a vital role in the protective procession of ischemic postconditioning on lung ischemic reperfusion.     

再灌注损伤挽救激酶和线粒体膜通透性转换在肝缺血后处理中的作用

缺血后处理(IPO)能减轻肝脏缺血再灌注损伤[1].我们通过观察缺血后处理对磷脂酰肌醇-3激酶(PI3K)、细胞外信号调节激酶1/2(ERK1/2)和线粒体膜通透性转换(MPT)的影响,探讨肝脏IPO的作用机制. 一、材料与方法 1.动物及分组:健康成年雄性SD大鼠56只随机分为7组,每组8只,分别为假手术(S)组、LY294002(PI3K抑制剂)+假手术(LY+S)组、PD98059(MAPKK抑制剂)+假手术(PD+S)组、缺血再灌注(IR)组、缺血后处理(IPO)组、LY294002+缺血后处理(LY +IPO)组和PD98059+ IPO( PD+ IPO)组.     

Cardioprotection by St Thomas' solution is mediated by protein kinase C and tyrosine kinase

BACKGROUND: Intracellular signaling pathways, specifically the activation of protein kinase C and tyrosine kinase, are essential to the cardioprotection of ischemic preconditioning. We proposed that activation of PKC and TK contribute to the myocardial protection of St. Thomas' No. 2 cardioplegia solution (STC). MATERIALS AND METHODS: Isolated rat hearts were exposed to 40 min of global ischemia followed by 120 min of reperfusion. Before ischemia, hearts received no treatment (control; n = 7), STC (n = 7), phorbol 12-myristate 13-acetate (PMA; n = 6), PMA + chelerythrine (n = 6), anisomycin (n = 6), anisomycin + genistein (n = 7), STC + chelerythrine (n = 7), STC + genistein (n = 7), PMA + genistein (n = 7) or anisomycin + chelerythrine (n = 7). Left ventricular developed pressure (LVDP) recovery, myocardial infarct size, and lactate dehydrogenase release were measured. RESULTS: STC as well as PMA (protein kinase C activator) and anisomycin (tyrosine kinase activator) significantly reduced infarct size (6.9 +/- 2.9%, 9.6 +/- 2.1%, 14.0 +/- 4.4%) compared with controls (42.4 +/- 2.9%, P < 0.05). The infarct reduction of PMA and anisomycin were blocked by their inhibitors chelerythrine and genistein, respectively. Both chelerythrine (29.2 +/- 4.1%, P < 0.05) and genistein (40.4 +/- 4.3%, P < 0.05) attenuated the reduction of infarct size provided by STC. The recovery of LVDP improved with STC, PMA and anisomycin (72.6 +/- 1.4%, 60.4 +/- 4.7%, 57.2 +/- 4.6%) compared with control (33.8 +/- 3.6%, P < 0.05). Addition of chelerythrine or genistein to STC impaired recovery of LVDP (52.3 +/- 4.4%, 35.1 +/- 2.5%, P < 0.05) compared with STC treatment. CONCLUSION: Administration of the pharmacologic inhibitors chelerythrine and genistein blunts the cardioprotection caused by STC treatment.     

细胞外信号调节激酶及应激活化蛋白激酶通路蛋白在瘢痕疙瘩成纤维细胞中的表达

目的通过比较瘢痕疙瘩及正常皮肤中细胞外信号调节激酶(extracellular signal-regulated kinase,ERK)、应激活化蛋白激酶(c-Jun amino-terminal kinase,JNK)信号通路的表达,探讨其在瘢痕疙瘩形成中的作用。方法取四川大学华西医院烧伤整形科收治的26例患者皮肤组织,其中行瘢痕疙瘩切除患者(实验组)16例,瘢痕疙瘩形成时间8个月～10年;胸部6例,耳垂4例,会阴部2例,肩部3例,腹部1例;均经病理检查确诊为瘢痕疙瘩。10例整形手术患者自愿捐赠的正常皮肤作为对照组,腹部4例,大腿3例,肩部2例,背部1例。取标本采用Envision二步法行免疫组织化学染色,观察磷酸化及非磷酸化JNK和ERK表达情况,并采用Image Pro Plus 4.5图像分析系统测定积分吸光度(IA)值,观察阳性染色强度。结果免疫组织化学染色观察显示,对照组正常皮肤成纤维细胞中未见明显的磷酸化及非磷酸化ERK、JNK阳性表达;而实验组主要在成纤维细胞中表达,阳性颗粒主要位于细胞质和细胞核内。实验组磷酸化ERK及JNK的IA值明显高于对照组(P<0.05),非磷酸化ERK及JNK两组间差异无统计学意义(P>0.05)。结论磷酸化JNK、ERK信号通路蛋白在瘢痕疙瘩中异常高表达,提示该通路可能与瘢痕疙瘩形成密切相关。     

酪氨酸蛋白激酶抑制剂的抗生育效应及研究进展

酪氨酸蛋白激酶(PTKs)是一组酶系,是在正常和异常增殖过程中起重要作用的癌蛋白和原癌蛋白家族中的成员。多种生长因子受体都有PTKs活性。PTKs途径的激活属于与细胞的生长、增殖和分化有关的信号途径。目前,PTKs抑制剂主要用于抗肿瘤。本文阐述PTKs抑制剂通过三种途径:(1)干扰胚泡与子宫内膜的相互识别及相互作用;(2)干扰激素导致子宫内膜不能接受胚泡着床;(3)通过免疫抑制和诱导细胞凋亡造成对胚胎排斥而产生抗生育效应。     

Mitogen-activated protein kinase cascade and cell cycle-related genes in the kidney

Recent studies have shown that mitogen-activated protein kinase (MAPK) consists of at least 3 subfamilies, including the classical MAPK, stress-activated protein kinase/c-Jun N-terminal kinase, and p38 kinase. Transforming growth factor (TGF)-β-activating kinase-1 (TAK1) is a novel MAP kinase kinase (MAPKK) that is reported to stimulate the p38 kinase and/or c-Jun N-terminal kinase pathway. TAKdN, the active form of TAK1, inhibits [³H]-thymidine uptake, and reduces the percentages of cells in the S and G₂/M phases of the cell cycle. TAKK63W, the negative, or inactive form of TAK1, ameliorates the inhibition of³H-thymidine uptake and the percentages of cells in S and G₂/M phases induced by TGF-β. Overexpression of TAKdN inhibits cyclin D1 gene promoter activity and protein expression. In contrast, constitutive active MKK1, the classical p42/44 MAPK activator, increases cyclin D1 promoter activity and protein level. Overexpression of the active form of MKK1 increases [³H]-thymidine uptake, while the inactive form decreases the uptake. To elucidate the mechanisms of the cell cycle of mesangial cells, we produced adenovirus vectors containing the coding sequences of cyclin D1 (AxCAD1), p16^INK4 (AxCAp16), and p21^CIP1 (AxCAp21), and investigated whether transfer of these genes changes platelet-derived growth factor-and endothelin-1-induced proliferation of rat mesangial cells. AxCAp16 and AxCAp21 inhibits [³H]-thymidine incorporation and the mitogen-induced increase in cyclin-dependent kinase-4 activity, and reduces the percentage of cells in the S phase as well. Overexpression of cyclin D1 increases the percentage of the cells in the S and G₂ phases, and reduces cell size. These findings suggest that p16^INK4 and p21^CIP1 function as inhibitors of the proliferation of mesangial cells, induced by growth-promoting factors, and that deregulated expression of cyclin D1 causes disturbances in the cell cycle. This review was presented at the 40th Annual Meeting of the Japanese Society of Nephrology and received an Oshima Award for Young Investigators.     

DAPK在肿瘤中的研究进展

死亡相关蛋白激酶(death-associated protein kinase,DAPK)是钙调蛋白调节的丝氨酸/苏氨酸蛋白激酶,在整个凋亡系统中发挥着重要作用,是凋亡正性调节因子之一.DAPK被认为是抑癌基因,与肿瘤的发生、发展、转移密切联系,在肿瘤早期诊断、评价预后及基因靶向治疗等方面有重要意义.     

膀胱癌组织中蛋白激酶C的表达

目的　探讨蛋白激酶C(PKC)在膀胱癌发病机制中的作用及其意义。方法　应用免疫组化方法检测 82 例膀胱癌组织和12例正常膀胱组织中PKC和增殖细胞核抗原(PCNA)的表达。结果　膀胱癌组织中PKC阳性率为56.1%,显著高于正常膀胱组织的25.0%(P<0.05)。PKC表达与肿瘤分级、分期无显著相关性,复发者 PKC表达显著高于无复发者。膀胱癌 PKC阳性表达者的PCNA指数显著高于阴性表达者。结论　PKC异常表达促使细胞过度增殖,进而参与膀胱癌发病过程的调控。     

蛋白激酶C活性及δ亚型在肾透明细胞癌的表达

目的　探讨蛋白激酶C(PKC)、PKC δ在肾透明细胞癌中的表达及其临床意义。方法　采用PKC比活性测定和WesternBlotting方法检测 38例肾透明细胞癌和 5例正常肾组织中PKC比活性和PKC δ的表达。结果　癌组织和正常组织胞浆PKC比活性值分别为 ( 6 .97± 2 .6 5 )10 - 2 pmol·ml- 1 ·min- 1 和 ( 14 .16± 5 .6 7) 10 - 2 pmol·ml- 1 ·min- 1 ;而胞膜中的比活性值分别为( 2 7.90± 7.5 8) 10 - 2 pmol·ml- 1 ·min- 1 和 ( 5 7.0 6± 18.13) 10 - 2 pmol·ml- 1 ·min- 1 ;PKC δ在癌组织细胞胞浆中的相对灰度值小于 1,在胞膜中则大于 1,各病理分期和细胞分级间差异均有显著性 (P<0 .0 5 )。结论　PKC活性在肾透明细胞癌中下降 ,PKC δ表达与病理分期、细胞分级相关 ,是判断肾细胞癌预后的指标。     

蛋白激酶C在预处理脑保护中的作用

Protein kinase C may play a central role in preconditioning-induced cerebral protection.Current findings confirm that some PKC isoforms involve in signaling pathways of mediating cerebral isehemic/reperfusion injury.Our previous studying results suggest that PKCe,γ involve in early stage of morphine preconditioning-induced cerebral ischemic tolerance.Further studies on the role of PKC in cerebral ischemic tolerance will provide scientific evidences for exploring new method of cerebral protection.     

细胞外信号调节蛋白激酶在前列腺上皮内瘤组织中的表达及意义

目的 探讨细胞外信号调节蛋白激酶（ERK）在前列腺上皮内瘤（PIN）组织中表达的意义。方法 应用免疫组织化学SP法检测12例PIN、11例前列腺癌（PCa)及16例BPH组织标本中ERK的表达。结果 12例PIN标本均有表达,其中6例为高表达;11例PCa组织10例为阳性,但多为弱表达;16例BPH组织12例为阳性,表达也较弱。PIN组织中ERK表达与PCa组和BPH相比ERK在PIN组织中呈高表达,与早期前列腺癌的发生有密切关系。