肝癌切除肝缺血再灌注损伤前后的蛋白质组学变化◆

背景:肝癌切除肝缺血再灌注损伤可促进微小转移灶的侵袭转移并引起线粒体损伤.目的:比较肝癌切除手术过程中肝正常组织缺血再灌注损伤前后蛋白质表达谱的改变,筛查发生肝缺血再灌注损伤应激的相关蛋白质分子标志物并探讨可能机制.方法:应用双向等电聚焦/聚丙烯酰胺凝胶电泳建立20例肝癌切除患者肝缺血再灌注前与灌注后15 min肝正常组织的全细胞蛋白质和线粒体蛋白质表达图谱,并进行差异分析,应用基质辅助激光解吸离子化串联时间质谱对差异蛋白质点进行鉴定,并进行生物信息学分析.结果与结论:相同条件下对各组全细胞和线粒体蛋白样品分别进行3次双向电泳,筛选在3次电泳中均存在的差异点进行分析,在全细胞蛋白质图谱中共鉴定出5个差异蛋白,在线粒体蛋白质图谱中未鉴定出明显的差异蛋白.结果可见肝癌切除手术过程中肝缺血再灌注15 min即可使细胞骨架蛋白、热休克蛋白等细胞保护蛋白表达发生改变,同时有促进肿瘤转移的风险,需要采取预防措施降低影响,但线粒体蛋白表达基本未发生改变.     

兔脊髓缺血再灌注损伤与正常组蛋白质组的差异分析

目的建立脊髓缺血再灌注损伤双向凝胶电泳图谱,对照观察蛋白质的差异表达。方法建立脊髓缺血再灌注损伤模型,获取损伤和正常脊髓的蛋白质组双向电泳荧光图谱,观察差异蛋白的不同时间点的变化规律,建立缺血再灌注24 h与正常脊髓蛋白质组的匹配差异图谱,鉴定差异蛋白。结果成功建立损伤和正常的双向电泳荧光图谱和肽质量指纹图谱,比较再灌注损伤24 h组与正常组可检测到46个蛋白差异点,鉴定出10个差异蛋白。结论损伤24 h组较其他组变化明显,与正常脊髓的蛋白质组存在明显差异。     

P选择素及其单克隆抗体对肝、肾缺血再灌注时细胞凋亡的影响

目的：探讨Ｐ选择素及其单克隆抗体在肝、肾缺血再灌注时其表达对细胞凋亡的影响。方法：建立大鼠肝及肾缺血再灌注损伤模型,分别采用免疫组化链菌素抗生物素蛋白生物素酶标法和原位ＤＮＡ片断末端标记法检测有或无Ｐ选择素单抗治疗组肝、肾组织中Ｐ选择素表达及凋亡细胞。结果：大鼠肝、肾缺血再灌注时Ｐ选择素在肝、肾内广泛表达,肝、肾组织出现显著病理改变并发生细胞凋亡;Ｐ选择素单抗作用组肝、肾组织中Ｐ选择素未表达,无明显病理变化且细胞凋亡减少。结论：在肝、肾缺血再灌注时,Ｐ选择素介导了肝、肾内中性粒细胞积聚和细胞凋亡,并加重肝、肾损伤;抑制Ｐ选择素可减少肝、肾内中性粒细胞积聚和细胞凋亡,减轻肝、肾缺血再灌注损伤     

缺血预处理抑制大鼠胰腺移植缺血再灌注胰腺细胞凋亡:活性氧与线粒体DNA修复酶的作用

背景:缺血预处理可诱发机体内源性保护机制,可全面有效地防治器官移植缺血再灌注损伤.在胰腺移植过程中冷、热缺血均可导致移植胰腺缺血再灌注损伤,线粒体结构及功能与胰腺病变密切相关,近些年研究发现,线粒体DNA存在修复体系,其与线粒体DNA损伤之间的平衡决定了疾病的发生和转归.目的:观察缺血预处理对大鼠胰腺移植缺血再灌注损伤时的细胞凋亡的影响,分析线粒体DNA修复酶8-氧鸟嘌呤DNA糖基化酶和氧化应激在其中的变化规律及可能途径.方法:纳入健康雄性SD大鼠50只,其中20只为供体,10只为假手术组,另20只糖尿病造模后分为缺血再灌注组和缺血预处理组,每组10只.假手术组只行开、关腹手术,缺血再灌注组和缺血预处理组行异位全胰十二指肠移植.缺血再灌注组对应供体大鼠于获取供胰前以4℃ UW液灌洗20 min:缺血预处理组对应供体大鼠于获取供胰前阻断腹上动脉5 min,再灌注5 min,共2次.供胰均控制热缺血时间为15 min,冷缺血时间为180 min.再灌注后12 h检测血浆淀粉酶活性、血糖浓度及Caspase-3,9活化水平,流式细胞法检测腺泡细胞凋亡率,罗丹明123法检测线粒体膜电位,二氯荧光素法检测线粒体过氧化氢产生速率,高效液相色谱法检测线粒体DNA中8-氧鸟嘌呤质量浓度,荧光定量聚合酶链反应法检测8-氧鸟嘌呤DNA糖基化酶mRNA的表达,Westenn-blotting法检测细胞色素C释放、磷酸化Akt及线粒体8-氧鸟嘌呤DNA糖基化酶蛋白表达水平.结果与结论:缺血预处理可降低线粒体氧化应激,提高Akt磷酸化水平,从而上调8-氧鸟嘌呤DNA糖基化酶表达,减少线粒体DNA氧化损伤,抑制腺泡细胞凋亡,减轻移植胰缺血再灌注损伤.     

褪黑素对全肝缺血再灌注大鼠肺细胞凋亡的影响及相关机制

目的 探讨褪黑素对全肝缺血再灌注大鼠肺组织细胞凋亡的影响作用及相关机制.方法 30只SD大鼠随机分3组:褪黑素治疗组,缺血再灌注组与假手术对照组.阻断肝门30 min后开放血流,建立大鼠全肝缺血再灌注模型.褪黑素组与缺血再灌注组分别于肝门阻断前15 min和再灌注前10 min静脉注射褪黑素溶液或相同剂量溶剂,于再灌注1 h处死动物.假手术组不阻断肝门,于上述各相应时间点注射溶剂与处死动物.留取肺脏组织,原位末端转移酶(TUNEL)法检测细胞凋亡、PCR法检测Bcl-XL与Bax mRNA表达,考马斯亮兰法检测肺泡灌洗液(BALF)总蛋白含量,同时进行肺组织病理学检查.结果 与缺血再灌注组相比,褪黑素组病理学改变减轻;BALF总蛋白含量、细胞凋亡指数(AI)与Bax mRNA表达显著降低(P＜0.01);而Bcl-XL mRNA表达及Bcl-XL/Bax比值显著增加(P＜0.01).结论 褪黑素可能通过影响Bcl-XL/Bax比值来抑制大鼠全肝缺血再灌注后肺细胞凋亡.     

硫化氢延迟预处理对大鼠心肌蛋白质组学的研究

目的 采用蛋白质组学技术,观察硫化氢延迟预处理对大鼠心肌蛋白质表达的影响.方法 16只SD大鼠按随机数字表法分为生理盐水对照组和硫化氢预处理组,每组8只.尾静脉注射生理盐水和硫化氢预处理后24h建立心肌缺血/再灌注模型(缺血30 min、再灌注120 min).用双向凝胶电泳(2-DE)分离两组大鼠心肌组织蛋白质,2-DE图谱分析后找出表达差异的蛋白质,并用基质辅助激光解析-电离飞行时间质谱(MALDI-TOF-MS)鉴定差异蛋白质.结果 对照组的蛋白质点数平均为929±14,硫化氢组的蛋白质点数平均为906±10,经凝胶图像分析找到表达差异蛋白质15个;用MALDI-TOF-MS对差异蛋白进行鉴定,共鉴定出11个蛋白质,包括多(聚)脱氧核糖核苷酸合酶、胱硫醚-γ-裂解酶、转录起始因子、NADH脱氢酶、鸟嘌呤核苷酸释放因子、果糖二磷酸醛缩酶A、糖原合成酶激酶-3、电子转移黄素蛋白、谷胱甘肽S转移酶、钙活化核苷酸酶、S-腺苷蛋氨酸合成酶.结论 硫化氢延迟预处理可使大鼠心肌组织蛋白表达发生改变,其心肌保护作用可能与改善能量代谢、抗氧化反应、细胞保护和保护呼吸链等有关.     

丙泊酚对大鼠肾缺血再灌注损伤细胞凋亡信号通路的影响

背景:肾移植中肾缺血再灌注损伤能引发凋亡程序的执行,丙泊酚可能的肾保护作用及其与细胞凋亡通路间的关系,有助于探讨丙泊酚的作用机制.目的:探讨丙泊酚对大鼠肾缺血再灌注损伤细胞凋亡通路的影响及可能的作用机制.设计,时间及地点:动物实验,细胞形态学观察,于2004/2005在北京友谊医院泌尿外科研究所实验室共同设计和完成.材料:选取封闭群SD成年雄性大鼠99只.兔抗鼠Bcl-2、Bax、caspase3、cytochrome C均为武汉博士德生物工程有限公司产品.方法:将动物随机分为对照组26只、缺血再灌注组35只、缺血再灌注+丙泊酚组38只.建立大鼠肾缺血再灌注损伤模型,术前单次静脉缓慢输注乳酸林格液5 mL/kg,逐层正中切口开骏,切除右肾,用无创血管夹夹闭左侧肾蒂,缺血时间45 min,松夹再灌注后全层缝合腹壁,取再灌注0,3,12,24,72 h左侧肾脏,取肾同时采血处死动物.缺血再灌注+丙泊酚组在缺血前15 min用药,丙泊酚1 mg/(kg·min)直至再灌注后30 min,共用药75 min.对照组和缺血再灌注组以乳酸林格液等量输注.主要观察指标:观察损伤肾的形态学改变,用免疫组织化学观察细胞凋亡相关蛋白Bcl-2、Bax、caspase 3和细胞色素C的表达情况.结果:光镜可观察到肾缺血再灌注引起的肾损害,程度依次为近曲小管、远曲小管、集合管、肾小球;免疫组化图像分析观察到缺血再灌注组与对照组相比,Bax、caspase 3,细胞色素C表达增加,Bcl-2表达未见明显变化;缺血再灌注+丙泊酚组与对照组比较,前者Bax、caspase 3和细胞色素C表达下降,Bcl-2表达增高(P＜0.05).结论:丙泊酚对肾缺血再灌注损伤引起的细胞凋亡可能具有保护作用,可能机制是抑制促凋亡蛋白Bax、caspase 3和细胞色素C的表达,对Bcl-2的表达无影响,与细胞凋亡的线粒体通路途径有关.     

大鼠全脑缺血再灌注损伤过程中细胞凋亡研究

目的：探讨在大鼠全脑缺血再灌注损伤过程中细胞凋亡的作用与意义。方法：采用四血管闭塞法复制大鼠全脑缺血再灌注模型,在光镜,电镜水平观察损伤病灶形态学改变,利用原位末端标记（TUNEL）法定量检测细胞凋亡指数。结果;大鼠全脑缺血30min后再灌注,细胞凋亡的发生随着缺血再灌注损伤时间变化,呈动态性改变,凋亡指数在再灌注24h达高峰,形态学观察预见细胞凋亡与坏死并存,结论：急性全脑缺血再灌注损伤过程中细胞凋亡与坏死同时存在,表明细胞凋亡参与急生全脑缺血再灌注的损伤过程。     

pifithrin-α抑制大鼠肝缺血再灌注早期PUMA蛋白的表达

背景：pifithrin-α是一种可逆性p53抑制剂,应用pifithrin-α抑制p53通路对肝脏缺血再灌注损伤的影响尚不清楚。目的：探讨核转录因子p53抑制剂对大鼠肝缺血再灌注后PUMA蛋白表达的影响。方法：96只雄性Wistar大鼠随机分为对照组,缺血再灌注组,缺血再灌注＋二甲亚砜溶媒对照组（二甲亚砜组）,缺血再灌注＋p53抑制剂pifithrin组（PFT组）。建立70%肝缺血模型,PFT组于60min的肝血流阻断结束时立即给予pifithrin-α,二甲亚砜组给予等量二甲亚砜溶液,对照组和缺血再灌注组给予等量生理盐水。结果与结论：大鼠肝缺血再灌注后1,3,6h肝组织PUMA蛋白表达明显,PFT组可以明显抑制PUMA蛋白的表达,但缺血再灌注24hPFT组PUMA蛋白的表达高于其他3组。结果可见pifithrin-α对肝脏缺血再灌注损伤有一定保护作用,其通过抑制p53从而诱导PUMA蛋白表达下调主要是在缺血再灌注早期。     

鼠肝缺血再灌注后肺组织ERK1/2通路活性变化及褪黑素的影响

目的探讨大鼠全肝缺血再灌注后肺组织损伤、修复过程中ERK1/2信号通路活性的动态变化与意义,以及褪黑素对该信号通路的影响。方法本实验将分成两部分完成。第一部分,36只SD大鼠随机分成6组（n=6）：①缺血前组;②再灌注0.5 h组;③再灌注3 h组;④再灌注6 h组;⑤再灌注12 h组;⑥再灌注24 h组。阻断肝门30 min后开放血流,建立大鼠全肝缺血再灌注模型。分别于缺血前5 min、再灌注0.5 h、3 h、6 h、12 h、24 h处死动物取肺,检测ERK1/2和p-ERK1/2表达、细胞凋亡、PCNA表达及肺组织病理学变化,观察肝缺血再灌注后肺组织ERK1/2信号通路活性的动态变化及其与细胞增殖、凋亡的关系。第二部分,将12只SD大鼠随机分成2组（n=6）：褪黑素组与基质对照组,依上述方法制备全肝缺血再灌注模型,分别于全肝缺血前15 min和再灌注前10 min静脉注射0.5%褪黑素溶液10 mg/kg或相同剂量的溶剂,于再灌注3 h处死动物取肺,检测前述相同参数,观察褪黑素的作用。结果 （1）与缺血前相比,全肝缺血再灌注后肺组织p-ERK/ERK比值与PCNA阳性指数均于再灌注0.5 h显著降低,此后逐渐增高;细胞凋亡指数则于再灌注0.5 h显著增高,后逐渐上升,再灌注6 h达最高,后又逐渐下降;肺组织病理于再灌注0.5 h即出现损伤改变,后逐渐加重,再灌注3 h最重,此后逐渐恢复。（2）双变量相关分析显示：p-ERK/ERK比值与PCNA阳性指数成正相关（r=0.85,P〈0.01）;与凋亡指数呈负相关（r=-0.38,P〈0.05）。（3）褪黑素组与基质对照组比较,p-ERK/ERK比值显著增加,细胞凋亡指数显著降低,病理学改变减轻,但PCNA阳性指数无明显变化。结论全肝缺血再灌注后肺组织损伤、修复过程中,ERK1/2信号通路活性呈先抑制后激活的变化方式,该通路可能通过抑制凋亡、促进增殖在损伤肺组织自身修复过程中发挥积极作用。褪黑素可激活ERK1/2信号通路,并可能由此减轻肝缺血再灌注后肺损伤。     

Hepatocyte apoptosis is enhanced after ischemia/reperfusion in the steatotic liver

Liver steatosis is associated with organ dysfunction after hepatic resection and transplantation which may be caused by hepatic ischemia/reperfusion injury. The aim of the current study was to determine the precise mechanism leading to hepatocyte apoptosis after steatotic liver ischemia/reperfusion. Using a murine model of partial hepatic ischemia for 90 min, we examined the levels and pathway of apoptosis, and the peroxynitrite expression, serum alanine aminotransferase levels, and liver histology 1 and 4 h after reperfusion. In the steatotic liver, the peroxynitrite expression increased after ischemia/reperfusion. Significant hepatocyte apoptosis in the steatotic liver was seen after reperfusion, caused by upregulation of cleaved caspases 9 and 3, but not caspase 8. Serum alanine aminotransferase levels were elevated and histological examination revealed severe liver injury in the steatotic liver 4 h after reperfusion. In mice treated with aminoguanidine, ischemia/reperfusion-induced increases in serum alanine aminotransferase levels and apoptosis were significantly reduced in steatotic liver compared with mice treated with phosphate buffered saline. Survival of mice with steatotic livers significantly improved by treatment with aminoguanidine. Our data suggested that the steatotic liver is vulnerable to hepatic ischemia/reperfusion, leading to significant hepatocyte apoptosis by the mitochondrial permeability transition, and thereby resulting in organ dysfunction.     

缺血预处理大鼠自体肝移植后剩余肝细胞的凋亡和增殖

背景:肝脏缺血再灌注损伤后肝细胞受到增殖和凋亡的双重调控.肝大部切除后,余肝经历缺血再灌注损伤,其肝再生受到明显抑制,缺血预处理可减轻此损伤,促进肝再生,其机制是否也与这有关,目前未见相关报道.目的:探讨缺血预处理对大鼠自体肝移植后余肝肝细胞凋亡和增殖的影响.设计、时间及地点:随机对照动物实验,于2006-09/2007-07在中南大学湘雅医学院实验动物中心完成.材料:雄性SD大鼠144只,随机分为3组:单纯肝叶切除组、自体肝移植组、缺血预处理组,48只/组.方法:单纯肝叶切除组大鼠只行肝左、中叶切除,不阻断肝右、尾叶血流.自体肝移植组大鼠结扎切断肝后与食管腹段之间的静脉交通支,游离liberate尾状叶,游离第一肝门、肝上及肝下下腔静脉后,阻断并经门静脉持续低温灌注保存液,同时进行无血肝切除(切除肝左、中叶),肝脏在体持续低温灌洗15 min.解除肝门阻断,完全恢复肝脏血流.快速复温肝脏表面,并冲洗腹腔,缝合关腹.缺血预处理组大鼠在门静脉灌注前先阻断肝右、尾叶血流10 min,然后开放血流10 min,余步骤同自体肝移植组.各组大鼠分别于肝叶切除后0,1,3,6,12,24,48,72 h时取材.主要观察指标:生化分析仪测定血清丙氨酸氨基转移酶及天冬氨酸氨基转移酶的水平,流式细胞仪检测肝细胞凋亡指数,通过Ki-67抗原的表达检测肝细胞增殖情况.结果:与自体肝移植组比较,除肝叶切除后0 h 外,其余各时间点单纯肝叶切除组、缺血预处理组血清丙氨酸氨基转移酶和天冬氨酸氨基转移酶水平均明显降低(P < 0.05).各组在肝叶切除后0 h(即正常肝组织)基本不存在凋亡细胞;单纯肝叶切除组肝大部切除后余肝肝细胞凋亡指数稍有升高;自体肝移植组复灌注后肝细胞凋亡指数急剧升高,约在12 h达到高峰,而后逐渐下降;与自体肝移植组比较,缺血预处理组肝细胞凋亡指数明显降低(P < 0.05).各组Ki-67表达率在肝叶切除后均明显升高,约在24 h达高峰,而后逐渐下降.与单纯肝叶切除组比较,自体肝移植组Ki-67表达率明显降低(P < 0.05);与自体肝移植组比较,缺血预处理组Ki-67表达率明显增高(P < 0.05).结论:缺血预处理可减轻自体肝移植后肝缺血再灌注损伤所致肝细胞凋亡,促进肝细胞增殖,这可能是其促进肝再生的机制之一.     

MMP-9抑制剂对大鼠肝脏缺血再灌注模型的影响分析

目的探讨基质金属蛋白酶-9(MMP-9)抑制剂对大鼠肝脏缺血再灌注模型的影响。方法选择36只健康雄性Wistar大鼠,将其随机分成3组,对照组(大鼠未进行任何处理不建立肝脏缺血再灌注模型)12只,模型组(肝脏缺血再灌注模型组建立前采用生理盐水处理)12只大鼠,实验组(肝脏缺血再灌注模型建立前采用盐酸多西环素处理)12只。检测各组大鼠肝脏缺血再灌注1 h、6 h、24 h血清天冬氨酸氨基转移酶(AST)与丙氨酸氨基转移酶(ALT)含量;观察评价肝脏组织损伤情况,肝脏组织的淤血、空泡样变、坏死程度以及MMP-9水平。结果模型组与实验组再灌注1 h、6 h、24 h的血清ALT与AST水平、肝组织病理评分均显著高于对照组(P <0.05)实验组低于模型组(P <0.05),模型组和实验组在肝脏缺血再灌注6 h时血清ALT与AST水平最高(P <0.05)。模型组与实验组再灌注1 h、6h、24 h的肝组织MMP-9相对表达水平均显著低于对照组(P <0.05),实验组高于模型组(P <0.05)。结论 MMP-9抑制剂能抑制大鼠肝脏缺血再灌注损伤,促进恢复大鼠的肝功能,缓解肝组织病变状况。     

Carbon monoxide, but not endothelin-1, plays a major role for the hepatic microcirculation in a murine model of early systemic inflammation

OBJECTIVE: Endothelin-1 and carbon monoxide play a major role in the regulation of liver microcirculation in numerous disease states. During sepsis and endotoxemia, elevated formation of endothelin-1 results in reduced sinusoidal blood flow. However, the role of carbon monoxide and endothelin-1 and its receptors endothelin receptor A and endothelin receptor B in the deranged liver microcirculation during early systemic inflammation remains unclear. DESIGN: Prospective, randomized, controlled experiment. SETTING: University animal laboratory. SUBJECTS: Male C57/BL6 mice, weighing 23-27 g. INTERVENTIONS: To induce a systemic inflammation, mice were treated with 1 hr of bilateral hind limb ischemia followed by 3 hrs or 6 hrs of reperfusion. Animals were randomly exposed to the nonselective endothelin receptor antagonist Ro-61-6612 (Tezosentan) and/or a continuous endothelin-1 infusion. Different animals were randomized to methylene chloride gavage or carbon monoxide inhalation during the reperfusion period. MEASUREMENTS AND MAIN RESULTS: After ischemia/reperfusion, endothelin-1 plasma concentrations, endothelin-1 messenger RNA expression, and endothelin receptor A and B messenger RNA expression revealed no significant changes when compared with sham animals. After 6 hrs of ischemia/reperfusion, hepatic microcirculatory variables (sinusoidal density, sinusoidal diameter, and red blood cell velocity) deteriorated. Tezosentan after 6 hrs of ischemia/reperfusion did not improve the liver microcirculation, whereas the continuous infusion of endothelin-1 after 6 hrs of ischemia/reperfusion further impaired sinusoidal blood flow. Tezosentan treatment did not produce any alterations in hepatocellular injury or hepatic redox status when compared with the untreated animals receiving 6 hrs of ischemia/reperfusion. Animals receiving 6 hrs of ischemia/reperfusion and exposed to methylene chloride gavage or inhaled carbon monoxide during limb reperfusion showed significantly improved microcirculatory variables, hepatic redox status, and attenuated hepatocellular injury. CONCLUSIONS: These data suggest that endothelin-1 and the endothelin receptors A and B are not responsible for the observed hepatic microcirculatory and cellular dysfunction during early systemic inflammation, but exposure to exogenous carbon monoxide protected the hepatic microcirculation and improved the impaired hepatic cellular integrity and the hepatocellular redox status.     

缺血预处理减轻大鼠减体积肝移植损伤并促进肝再生

背景:近年来,肝移植技术迅速发展,如何预防缺血再灌注损伤并有效保护肝再生成为研究的热点.缺血预处理是保护肝缺血损伤的有效方法,但其确切机制尚存争议.目的:研究缺血预处理在大鼠减体积肝移植肝损伤和肝再生中的作用及机制.方法:动物随机分为3组,肝移植组建立大鼠减体积肝移植模型.缺血预处理+肝移植组在供肝灌注前阻断第1肝门行缺血预处理10 min,再灌注15 min.假手术组在开腹后游离肝周韧带,然后关腹.分别于术后0.5,2,6,24 h取材.通过血清谷丙转氨酶水平和移植肝组织病理检查评估肝损伤.半定量免疫组织化学和western blot法测定氧化还原蛋白1表达水平,检测移植肝细胞增殖细胞核抗原评估肝再生情况.结果与结论:与肝移植组相比,缺血预处理+肝移植组术后6,24 h受体血清谷丙转氨酶明显降低(P<0.05;P<0.01).病理学分析显示肝移植组术后24 h可见到门脉周围大量炎细胞浸润,肝窦扩张明显,肝组织损伤较重;而缺血预处理+肝移植组则损伤较轻.半定量免疫组织化学显示缺血预处理+肝移植组移植肝中Ref-1蛋白表达明显增加,这一结果同样在westernblot检测中得到验证:缺血预处理+肝移植组移植肝术后24 h Ref-1蛋白表达较肝移植组明显增强(P<0.05).同时,术后2,6和24 h缺血预处理+肝移植组增殖细胞核抗原阳性细胞数较肝移植组明显增加(P<0.05).结果提示缺血预处理可减轻大鼠减体积肝移植术后早期移植物肝损伤并促进肝再生,这与Ref-1蛋白高表达密切相关.     

17β-estradiol attenuates reduced-size hepatic ischemia/reperfusion injury by inhibition apoptosis via mitochondrial pathway in rats

The aim of this study was to investigate the effect of 17β-estradiol (E2) on hepatocyte apoptosis after reduced-size hepatic ischemia/reperfusion (I/R) injury and its mechanism. A rat model of reduced-size hepatic I/R injury was established. Sprague-Dawley rats were randomly allocated into sham, I/R, and E2 + I/R group. 17β-Estradiol (4 mg/kg) or the vehicle was administered i.p. 1 h before ischemia and immediately after operation. For each group, 10 rats were used to investigate the survival during a week after reperfusion. Blood samples and liver tissues were obtained in the remaining animals after 3, 6, 12, and 24 h of reperfusion to assess serum aspartate aminotransferase and alanine aminotransferase levels, liver tissue malondialdehyde concentration, superoxide dismutase activity, and histopathologic changes. Apoptosis ratio; expression of cytochrome c, Bcl-2, and Bax proteins; and enzymatic activities of caspase 9 and caspase 3 were performed in the samples at 12 h after reperfusion. The serum aspartate aminotransferase and alanine aminotransferase levels and tissue malondialdehyde concentration were increased in the I/R group, whereas the increase was significantly reduced by E2. The superoxide dismutase activity, depressed by I/R injury, was elevated back to normal levels by treatment with E2. Severe hepatic damage was observed by light microscopy in the I/R group, whereas administration of E2 resulted in tissue and cellular preservation. Furthermore, E2 inhibited hepatocellular apoptosis by upregulating the ratio of Bcl-2 and Bax expression, reduced cytosolic cytochrome c level, and decreased caspase 9 and caspase 3 activities. The 7-day survival rate was significantly higher in the E2 + I/R group than in the I/R group. These results indicated that E2 protects liver tissues from reduced-size hepatic I/R injury by suppressing mitochondrial apoptotic pathways.     

Endothelial nitric oxide synthase protects the post-ischemic liver: potential interactions with superoxide.

Hepatic ischemia and reperfusion (I/R) continues to represent a significant cause of post-transplant liver failure. The roles that certain free radicals including nitric oxide (NO) and superoxide (O(2)(-)) play in this process are not well understood. The present study was designed to assess the role of endothelial cell nitric oxide synthase (eNOS) in I/R-induced liver injury in a murine model of hepatic I/R. Forty five minutes of partial (70%) hepatic ischemia followed by 3 and 6 h of reperfusion resulted in a significant increase in liver injury which occurred in the absence of neutrophil infiltration. eNOS-deficient mice displayed enhanced liver injury when compared to their wild type controls again in the absence of neutrophil infiltration. Interestingly, basal liver blood flow was significantly decreased in these mice when compared to controls though their blood flow during reperfusion was not significantly reduced from their wild type controls. Treatment of eNOS(-/-) mice with gadolinium chloride, a potent inhibitor of Kupffer cell function, but not superoxide dismutase, significantly reduced post-ischemic hepatocellular injury while either treatment protected the wild type mouse livers. Taken together, these data suggest that NO derived from eNOS may act to protect the post-ischemic liver possibly by suppression of Kupffer cell function and not by modulation of tissue perfusion. Further the data presented here would indicate that the protective effects conferred by SOD are related to its ability to increase the bioavailability of NO rather than by attenuating superoxide-dependent reactions. Data generated from these studies may prove useful in developing new drug therapies to treat the post-ischemic liver.     

乌司他丁对肝缺血-再灌注后急性肺损伤的保护作用

目的 :观察肝缺血再灌注后急性肺损伤的发病机制及乌司他丁的干预作用。方法 :建立大鼠部分肝缺血再灌注模型 ,随机分为手术对照组 (对照组 ) ,肝缺血 90 min组 (缺血组 ) ,肝缺血 90 m in、再灌注 12 0 m in组 (再灌注组 ) ,缺血前 30 m in静脉注射乌司他丁 +肝缺血 90 min、再灌注 12 0 min组 (乌司他丁组 )。检测支气管肺泡灌洗液 (BAL F)中总蛋白含量、肺组织干 /湿质量比 (D/ W)、肺组织髓过氧化物酶 (MPO)含量及血浆中丙二醛 (MDA)含量。结果 :1与对照组比较 ,肝缺血再灌注损伤后各组大鼠 BAL F中总蛋白含量均明显升高(P<0 .0 5或 P<0 .0 1) ,再灌注组总蛋白升高更为明显 ,乌司他丁能干预其升高 ;肺 D/ W则均明显降低(P均 <0 .0 1) ,乌司他丁能干预其降低程度。 2随着肝缺血再灌注的发生 ,肺组织 MPO与血浆 MDA含量均逐渐升高 ,以再灌注组升高更明显 (P均 <0 .0 1) ,乌司他丁能干预 MDA和 MPO的升高。结论 :肝缺血再灌注后急性肺损伤的主要病理生理过程是氧化抗氧化系统的失衡 ,中性粒细胞是肺组织急性损伤的主要炎性细胞 ;乌司他丁通过抑制中性粒细胞在肺组织中的渗出及其抗氧化作用显著减轻急性肺损伤的程度。     

肝移植后缺血再灌注损伤大鼠诱导细胞凋亡中的一氧化氮

背景：由诱生型一氧化氮合酶产生的一氧化氮,是肝脏缺血再灌注损伤中病理生理学改变的一个重要因素。目的：探讨一氧化氮在肝移植缺血再灌注诱导的肝细胞早期凋亡的影响以及相关基因caspase-3的表达情况。方法：受体鼠72只随机数字表法均分成移植组、精氨酸组及L-硝基精氨酸甲酯组,均建立原位肝移植模型,后2组大鼠在开放血流前5min于股静脉注射可升高血清一氧化氮水平的精氨酸或一氧化氮抑制剂L-硝基精氨酸甲酯。移植造模后剩余的24只大鼠设为假手术组。结果与结论：血清谷草转氨酶活性比较,精氨酸组〈移植组〈L-硝基精氨酸甲酯组,组间比较差异有显著性意义（P〈0.01）;血清一氧化氮浓度,精氨酸组〉移植组〉L-硝基精氨酸甲酯组;早期凋亡的高峰期为再灌注后3h,肝细胞的活细胞数比例及肝组织中caspase-3的表达,精氨酸组〈移植组〈L-硝基精氨酸甲酯组。说明,一氧化氮对大鼠对肝移植缺血再灌注后肝细胞早期凋亡具有保护作用,且该作用可能主要通过下调caspase-3基因的表达。