目的:探讨儿茶酚抑素( CST)对间歇低氧高血压大鼠的作用及机制。方法:健康雄性SD大鼠随机分为3组:control组、IH (间歇低氧组)组和IH+CST组(于低氧前3 d皮下埋植含CST 20 nmol? kg -1? d-1的微量渗透泵)。后2组置于间歇低氧舱中,舱内氧浓度为(5±0.5)%~(21±0.5)%,低氧-复氧循环时间为120 s(60 s+60 s),8 h/d,共3周。颈总动脉插管测收缩压(SP)、舒张压(DP)和平均压(MP),检测血浆中氧化/抗氧化损伤指标,Western blot 法检测主动脉和肾组织中核因子E2相关因子2(Nrf2)蛋白表达的变化。结果:SP、DP及MP,IH组均比control 组高(P<0.01),而IH+CST 组则显著低于IH 组(P<0.01)。 IH组的MPO和MDA含量显著高于control组(P<0.05),而SOD和羟自由基抑制率显著低于control组(P<0.01);IH+CST组的MPO和MDA明显低于IH组(P<0.05),SOD和羟自由基抑制率显著高于IH组(P<0.01)。与control组相比, IH组大鼠主动脉和肾组织胞浆、胞核中Nrf2蛋白的表达均显著下调(P<0.05);IH+CST组与IH组相比,胞浆中Nrf2蛋白的表达显著下调(P<0.05),而胞核中Nrf2蛋白的表达显著上调(P<0.05)。结论:CST有减轻间歇低氧致大鼠高血压的作用,该作用可能与其通过Nrf2-ARE信号通路调节氧化应激反应有关。
作者:陈然;范小芳;郑青青;丁露;薛峰;王永煜;龚永生 刊期: 2016年第08期
目的:房室传导阻滞是心脏电激动传导过程中,发生在心房和心室之间的电激动传导异常,可导致心律失常。前期,我们发现一个遗传性房室传导阻滞伴肥厚型心肌病家系,本次工作主要对其致病基因及机制进行研究。方法:采用候选基因测序的方法对已经确诊为房室传导阻滞的心脏病患者进行致病基因分析,对报道与心脏病相关的 TRP4、 SCN5A、 SCN1B、NKFX2.5、CLCA2和LMNA共6个基因测序并确定致病基因;构建致病基因的野生型和突变型质粒;克隆野生型和突变型,激光共聚焦显微镜检测野生和突变型蛋白在细胞定位,利用Western blot检测目的蛋白的表达情况对该突变功能进行分析。结果:遗传学分析显示在家系中患者LMNA基因第10号外显子缺失,并与疾病共分离。 Western blot结果显示突变型lamin蛋白表达水平正常,定位结果显示,野生型蛋白位于细胞核核膜,而突变型蛋白在核膜上和核内均有表达。 LMNA异常可引起房室结细胞死亡与纤维化,导致房室传导速率降低,并发生房室传导阻滞。自噬和凋亡是细胞死亡的重要形式,LC3-II是检测自噬的标志蛋白。应用Western blot检测LC3-II,结果显示LMNA突变不影响该蛋白表达。结论:本次研究中,我们发现了一个新的导致遗传性房室传导阻滞伴肥厚型心肌病的LMNA基因突变,该突变可使其编码的蛋白不能正确定位于细胞核膜,导致细胞核核纤层结构异常。核纤层在细胞分裂中呈现周期性的变化,因此核纤层的异常会对细胞正常周期产生重要影响从而导致细胞的异常死亡。这可能是导致该家族成员发生房室传导阻滞的原因。
作者:曹祝兵;李思思;臧小彪;凃欣 刊期: 2016年第08期
AIM:To investigate the effect of miR-214 on cardiomyocyte hypertrophy and the expression of the potential target genes . METHODS:A cell model of hypertrophy was established based on angiotensin-Ⅱ( Ang-Ⅱ)-induced neonatal mouse ventricular car-diomyocytes (NMVCs).Dual luciferase reporter assay was performed to verify the interaction between miR-214 and the 3’ UTR of MEF2C.The expression of MEF2C and hypertrophy-related genes at mRNA and protein levels was determined by RT-qPCR and Wes-tern blotting, respectively.RESULTS:The expression of ANP, ACTA1,β-MHC and miR-214 was markedly increased in Ang-Ⅱ-in-duced hypertrophic cardiomyocytes .Dual luciferase reporter assay revealed that miR-214 interacted with the 3’ UTR of MEF2C, and miR-214 was verified to inhibit MEF2C expression at the transcriptional level .The protein expression of MEF2C was markedly in-creased in the hypertrophic cardiomyocytes .Moreover, miR-214 mimic, in parallel to MEF2C siRNA, inhibited the expression of hy-pertrophy-related genes in Ang-Ⅱ-induced NMVCs.CONCLUSION:MEF2C is a target gene of miR-214, which mediates the effect of miR-214 on attenuating cardiomyocyte hypertrophy .
作者: 刊期: 2016年第08期
目的:比较柠檬酸镁与乳糖用于建立SD大鼠慢性渗透性腹泻模型的可行性和实验适用性,为大鼠慢性渗透性腹泻模型的建立提供方法学基础。方法:5周龄SPF级SD大鼠31只,随机分为正常对照( Con )组、柠檬酸镁腹泻( Mg)组以及乳糖腹泻( Lac)组。 Lac组用高乳糖饲料喂养,自由饮水;Mg组用基础饲料喂养,自由饮用柠檬酸镁溶液(镁离子浓度为4.77 g/L),不另外给予普通饮用水;Con组用基础饲料喂养,自由饮水。每天观测大鼠的一般情况和腹泻情况,腹泻14 d后测试肌力和自主活动度。随后处死全部大鼠,取结肠中段检测肠黏膜跨肠上皮电阻;取小肠下段和结肠中段,HE染色观察肠黏膜病理学变化。结果:两腹泻组大鼠均出现体重增长缓慢、毛发稀疏无光泽、乏力、活动减少等临床表现,腹泻率和腹泻指数均显著高于Con组( P<0.05);Lac组腹泻指数明显高于Mg组(P<0.05),但Mg组小肠黏膜破坏程度较Lac组稍严重。结论:两种腹泻模型均能达到慢性腹泻的要求,但存在各自的优势,需根据实验需求选择恰当的模型。
作者:刘舒;高媛;肖露;杨亭;李廷玉;陈洁 刊期: 2016年第08期
目的:我们的前期实验发现,腺病毒中介的peroxiredoxin II ( Prx II)过表达可保护心肌细胞防止氧化应激所致的损伤,尽管这样,Prx II在器官和整体动物水平是否具有心肌保护作用,而且这一保护作用是否通过内质网应激发挥作用尚不清楚。方法:应用Langendorff系统构建离体心肌缺血再灌注损伤模型;结扎冠状动脉左前降支,缺血30 min再灌注30 min/3 h/24 h构建体内心肌缺血再灌注损伤模型。结果:离体心肌缺血再灌后,Prx II过表达小鼠心肌收缩大速率(+dp/dtmax )和心肌舒张大速率(-dp/dtmax )恢复较正常对照组明显得到改善;Prx II心肌特异性过表达小鼠与野生型相比,离体和在体心肌缺血再灌后,心肌梗死面积均分别降低了69.13%和60.86%;体内心肌缺血再灌注,与野生型小鼠相比,Prx II心肌特异性过表达小鼠心肌细胞凋亡率降低了52.10%±5.32%;与野生型小鼠相比,Prx II心肌特异性过表达小鼠中内质网通路伴侣分子Hsp90、GRP94、PDI和p-eIF2α的表达量均明显降低(P<0.05),但cleaved ATF6和XBP-1的表达量在2组小鼠中无明显差异。 p-Akt (Ser473)和p-Akt(Thr308)水平在野生型小鼠明显降低,在Prx II过表达小鼠中仍维持高表达水平(P <0.05)。结论:Prx II对缺血再灌注损伤心肌具有保护作用,其机制可能与拮抗p-eIF2α表达、增加p-Akt表达、阻断内质网应激启动的凋亡通路有关。
作者:王慧敏;石晓静;周文娟;耿雪鹏;姬亚歌;肖悦;黄欣;刘宏民;赵文 刊期: 2016年第08期
目的:探讨核仁素对心肌梗死后巨噬细胞极化的影响及其作用机制。方法:采用小鼠心肌梗死模型;采用心肌内注射核仁素RNA干扰的慢病毒载体,从整体水平观察核仁素低表达对小鼠心梗后死亡率的影响及对巨噬细胞极化的影响;采用流式细胞术检测巨噬细胞极化情况。结果:心肌梗死1 d后,核仁素表达减少,3 d后表达增加,5 d后明显升高,达(2.73±0.47)倍,7 d后有所下降。小鼠心肌梗死2 d、5 d后,心肌中巨噬细胞明显增多;心肌梗死2 d后心肌中M1型巨噬细胞占77.71%,而心肌梗死5 d后心肌中M2型巨噬细胞占82.13%。核仁素低表达可抑制心肌梗死5 d后M2型巨噬细胞的极化,但对巨噬细胞的侵润无明显影响,可明显减少心肌梗死后28 d的存活率。核仁素过表达可使巨噬细胞极化相关基因NOTCH1和STAT6的mRNA水平表达上调,而核仁素低表达可下调NOTCH1和STAT6的mRNA表达水平。结论:核仁素可调控心梗后巨噬细胞的极化,核仁素低表达可增加小鼠心梗后死亡率。
作者:蒋碧梅;吕青兰;李媛彬;刘梅冬;刘可;涂自智;肖献忠 刊期: 2016年第08期
目的:探讨NAD(P)H醌氧化还原酶1[NAD(P)H-quinone oxidoreductase 1,NQO1]过表达在卵巢黏液性囊腺癌临床预后评估中的意义。方法:应用免疫组化EnVision法检测NQO1蛋白在162例卵巢黏液性囊腺癌组织、35例卵巢黏液性囊腺瘤组织和29例正常卵巢上皮组织中的表达,并分析其过表达与卵巢黏液性囊腺癌临床病理学特点之间的关系,通过Kaplan-Meier方法进行生存分析。结果:NQO1蛋白在卵巢黏液性囊腺癌组织中的阳性率及强阳性率分别为85.8%和64.2%,显著高于卵巢黏液性囊腺瘤和正常卵巢上皮组织(P<0.01)。卡方检验结果显示,NQO1蛋白高表达与卵巢黏液性囊腺癌组织学分级和FIGO分期密切相关( P<0.05)。 Kaplan-Meier生存分析显示,NQO1蛋白高表达的卵巢黏液性囊腺癌患者总生存期和无病生存期均明显低于NQO1蛋白低表达患者。结论:NQO1蛋白在卵巢黏液性囊腺癌组织中呈高表达,可能成为卵巢黏液性囊腺癌预后评估的有效生物学指标。
作者:徐明;杨洋;车拴龙;朴英实;林贞花;陈丽艳 刊期: 2016年第08期
目的:葡萄糖转运体4(GLUT4)在球囊损伤血管新生内膜中高表达,而其转位过程依赖于肌动蛋白(actin)细胞骨架的调节。平滑肌蛋白22α( smooth muscle protein 22α,SM22α)是一种actin细胞骨架相关蛋白,其在增殖性血管疾病中表达下调。本研究观察了SM22α是否参与血管损伤或者PDGF刺激诱导的GLUT4表达和转位活性升高。方法:用PDGF-BB刺激血管平滑肌细胞( vascular smooth muscle cell , VSMC),观察GLUT4膜转位和细胞骨架的变化;用荧光葡萄糖2-NBDG检测葡萄糖摄取;用特异性siRNA敲低内源性SM22α表达;BrdU实验检测细胞增殖;高效液相色谱法检测组织葡萄糖含量。结果:PDGF-BB诱导VSMCs GLUT4转位和葡萄糖摄取依赖于皮层F-actin聚合,而敲低SM22α促进这一过程。损伤新生内膜处GLUT4表达显著增加,PDGF-BB刺激促进细胞GLUT4表达和葡萄糖消耗,抑制GLUT4活性则显著降低细胞增殖活性。相对于WT组, SM22α-/-小鼠颈总动脉2-NBDG摄取显著增加,结扎后28 d新生内膜明显增厚,损伤动脉组织GLTU4转位和葡萄糖含量均明显升高。结论:PDGF-BB诱导的GLUT4转位和糖摄取参与VSMCs 增殖。缺失SM22α可诱导皮层细胞骨架聚合,增强PDGF-BB诱导的GLUT4膜转位和糖摄取及代谢活性。 SM22α是一种新的增殖相关糖代谢调节因子。
作者:赵丽丽;陈鹏;谢肖立;窦永青;聂磊;林燕玲;李晓坤;苗穗兵;董丽华;尹亚娟;张丹丹;宋昱;韩梅 刊期: 2016年第08期
目的:C1q/肿瘤坏死因子相关蛋白-3(CTRP3)是一种脂肪细胞因子,它与多种代谢性及心血管疾病密切相关,但CTRP3对线粒体生物生成的影响尚不清楚。本研究主要探讨CTRP3对心肌细胞线粒体生物生成的影响及相关机制。方法:原代培养乳大鼠心肌细胞并给予CTRP3处理。使用PCR、Western blot和免疫共沉淀等方法分别检测线粒体生物生成相关蛋白、线粒体DNA拷贝数、ATP含量和sirtuin 1( SIRT1)活性的变化。结果:CTRP3显著增加过氧化物酶体增殖激活受体共激活因子1α( PGC-1α)、核呼吸因子1( NRF-1)、线粒体转录因子A( TFAM)、线粒体氧化磷酸化复合物III和V的表达。 CTRP3显著升高心肌线粒体DNA拷贝数和ATP含量,而在心肌细胞中敲低PGC-1α可使上述效应减弱。预孵育腺苷酸活化蛋白激酶( AMPK)的抑制剂AraA可以逆转由CTRP3引起的NRF-1、TFAM和复合物III、V的表达升高。 CTRP3可上调SIRT1的表达和活性,SIRT1抑制剂EX-527可阻断CTRP3对PGC-1α的去乙酰化调节作用。此外,CTRP3对SIRT1表达和活性的促进作用也可被AraA所阻断。结论:CTRP3通过AMPK/PGC-1α通路促进心肌细胞线粒体生物生成。
作者:张城林;冯寒;李丽;王瑾瑜;张艳;吴立玲 刊期: 2016年第08期
目的:研究树鼩脑缺血及缺血后适应(postconditioning,PC)对酸敏感性离子通道(acid-sensing ion channel,ASIC)2a表达及海马微环境离子稳态性的影响,探讨ASIC2a在PC脑保护效应中的作用机制。方法:建立光化学诱导的树鼩血栓性脑缺血模型及PC模型,在观察脑组织病理形态学改变的基础上,利用单泵等速微灌流系统对海马离子微环境进行动态监测,并通过免疫组化、RT-PCR及Western blotting技术对树鼩海马组织内ASIC2a的表达进行定位和定量研究。结果:树鼩皮层脑血栓形成后引起了同侧海马神经元的继发性损伤及海马神经元微环境的紊乱;PC处理可减轻海马神经元缺血损伤性改变,并使海马微环境离子稳态失衡得以明显改善;脑缺血诱导树鼩海马ASIC2a蛋白及mRNA表达一过性增强,PC处理使得ASIC2a表达水平更高、持续时间延长(P<0.05)。结论:神经元微环境内离子稳态性异常是海马神经元继发性损伤的重要原因;PC可通过诱导ASIC2a表达上调,以强化机体内源性损伤防御机制,这也是其改善神经元微环境离子稳态性、提高缺血耐受性的关键所在。
作者:陈静;李树清 刊期: 2016年第08期
目的:观察AMPK对血管内皮细胞中电导和小电导钙激活钾离子通道(KCa3.1和KCa2.3)表达和功能的影响。方法:应用人脐静脉内皮细胞(human umbilical vein endothelial cells , HUVECs)细胞系CRL-1730,通过Western blotting和real-time PCR等方法检测AMPK激活和下调对内皮细胞上KCa3.1和KCa2.3通道蛋白和mRNA表达的影响;分离大鼠肠系膜三级动脉,加入AMPK的激动剂或(和)抑制剂,应用微血管张力测定仪观察KCa3.1和KCa2.3通道介导的血管内皮舒张功能的变化。结果:激活AMPK可以上调血管内皮细胞KCa3.1和KCa2.3通道蛋白和mRNA的表达,其作用可被AMPK抑制剂逆转;应用RNA干扰技术下调AMPKα1亚基可以抑制KCa3.1和KCa2.3通道蛋白的表达。激活AMPK可以增强KCa3.1和KCa2.3介导的血管舒张功能,其作用可被AMPK抑制剂逆转。结论:AMPK对HUVECs上KCa3.1和KCa2.3通道的表达具有上调作用,该作用至少部分涉及转录水平的调节;AMPK对KCa3.1和KCa2.3通道介导的舒张功能具有上调作用。
作者:宋征;王燕;庞正达;马晓真;王晓静;赵丽梅;邓秀玲 刊期: 2016年第08期
AIM:To investigate regulatory roles of Apelin in adventitial remodeling and fibrosis in rats with transverse aortic constriction ( TAC) .METHODS:The male Sprague-Dawley rats with TAC were randomized to daily deliver either pyroglutamyl Apelin-13 ( 50μg/kg) or saline for 4 weeks.RESULTS:Histomorphometric analysis by HE and Masson Trichrome staining revealed increased medi -al and adventitial thicknesses , especially in the adventitia , in ascending aortas in rats with TAC when compared with the sham-operated rats.Downregulation of APJ receptor and elevations in phosphorylated mTOR and ERK 1/2 levels were observed in rats with TAC . There are marked increases in heart weight ( HW) , HW/body weight ratio , and aortic fibrosis in rats with TAC .The pressure over-load-mediated pathological adventitial remodeling was strikingly rescued by Apelin-13, associated with attenuation of aortic fibrosis and reduced mRNA expression of TGF-β1, fibronectin and collagen I .CONCLUSION:Our results demonstrate the importance of Apelin-13 in amelioration of aortic adventitial remodeling and fibrosis in rats with TAC via modulation of the mTOR /ERK signaling , thus indi-cating potential therapeutic strategies by enhancing Apelin /APJ action for preventing pressure overload-and fibrosis-associated cardio-vascular disorders .
作者: 刊期: 2016年第08期
Angiotensin-converting enzyme 2 (ACE2)-angiotensin (1-7) [Ang (1-7)]-Mas constitutes the vasoprotective axis and is demon-strated to antagonize the vascular pathophysiological effects of the classical renin -angiotensin system .We hypothesize that upregulation of ACE2-Ang (1-7) signaling protects endothelial function through reducing oxidative stress , thus resulting in beneficial outcome in di-abetes.Ex vivo treatment with Ang (1-7) augmented endothelium-dependent relaxation (EDR) in renal arteries from diabetic patients . Both Ang (1-7) infusion via osmotic pump (500 ng? kg -1? min-1 ) for 2 weeks and exogenous ACE 2 overexpression mediated by ad-enoviral ACE2 via tail vein injection rescued the impaired EDR and flow-mediated dilatation ( FMD) in db/db mice.Diminazene acetu-rate treatment (15 mg? kg-1? d-1 ) activated ACE2, increased the circulating Ang (1-7) level, and augmented EDR and FMD in db/db mouse arteries.In addition, activation of the ACE2-Ang (1-7) axis reduced reactive oxygen species (ROS) overproduction de-termined by dihydroethidium staining , CM-H2DCFDA fluorescence imaging , and chemiluminescence assay in db/db mouse aortas and also in high-glucose-treated endothelial cells .Pharmacological benefits of ACE 2-Ang ( 1-7 ) upregulation on endothelial function were confirmed in ACE2 knockout mice both ex vivo and in vitro.We elucidate that the ACE2-Ang (1-7)-Mas axis serves as an important signal pathway in endothelial cell protection in diabetic mice , especially in diabetic human arteries .In summary, endogenous ACE2-Ang (1-7) activation or ACE2 overexpression preserves endothelial function in diabetic mice through increasing nitric oxide bioavail -ability and inhibiting oxidative stress , suggesting the therapeutic potential of ACE 2-Ang(1-7) axis activation against diabetic vasculop-athy.
作者: 刊期: 2016年第08期
目的:探讨梅花鹿二杠茸和三岔茸水提物对顺铂( CDDP)所致小鼠肾损伤的影响。方法:采用灌胃给药方式,用顺铂(15 mg/kg)诱导小鼠肾损伤模型,测定小鼠肾脏指数(KI)、血清肌酐(SCr)、血尿素氮(BUN)、肾脏组织中超氧化物歧化酶( SOD)和谷胱甘肽过氧化物酶( GSH-Px)活性及丙二醛( MDA)含量,并对肾脏组织进行HE染色,观察肾脏病理学变化,研究梅花鹿二杠茸和三岔茸的水提物各剂量对小鼠肾损伤的影响。结果:与顺铂组相比,各剂量鹿茸水提物可显著降低CDDP诱导肾损伤小鼠SCr、BUN水平及肾脏MDA含量,提高SOD和GSH-Px的活性( P<0.05);明显改善肾组织病理学形态,减轻CDDP对肾小管上皮细胞的损伤程度,且同等浓度下,与三岔茸相比,二杠茸水提物能更好地改善肾功能及减轻病理损伤。结论:鹿茸水提物减轻顺铂引起的小鼠肾损伤,其作用机制可能与鹿茸水提物增强小鼠肾脏组织的抗氧化能力有关。
作者:董思敏;王海璐;王全凯;张晶 刊期: 2016年第08期
目的:探讨高盐饮食对Dahl盐敏感大鼠肾小管上皮向间质转化( EMT )和肾脏纤维化的影响。方法:7~8周龄雄性Dahl盐敏感大鼠(SS, n=24)及SS-13BN大鼠(13BN, n=12),高盐、正常饮食干预4周与8周,测血压及血尿生化指标;用Masson染色评估肾脏纤维化程度;免疫组化和实时定量PCR检测肾小管上皮标志E-cadherin和间质细胞标志α-SMA mRNA和蛋白的表达情况。结果:(1)相较基线期,SS和13BN大鼠干预后收缩压增高,SS大鼠增高幅度更为明显;8周高盐干预时血压显著高于4周(P<0.01)。(2)4周高盐负荷后,2种大鼠肾脏均出现胶原纤维沉积,且SS高盐组多于13BN高盐组。8周时, SS高盐组肾小球和间质胶原沉积较4周进一步加重。(3)4周和8周高盐干预后,与SS正常饮食组相比,SS高盐组肾脏E-cadherin表达显著减少,α-SMA 表达明显增加。(4)肾脏纤维化程度与与肾小管EMT 的发生显著相关( E-cadherin: r =-0.787;α-SMA:r=0.866)。结论:高盐饮食可诱导Dahl盐敏感大鼠肾小管上皮细胞EMT的发生,促进肾脏纤维化。
作者:汪洋;牟建军;褚超;吕永波 刊期: 2016年第08期
AIM:NLRP3 inflammasome was identified as the cellular machinery responsible for activation of inflammatory processes .The present study investigated whether the activation of NLRP 3 inflammasomes contributes to hyperhomocysteinemia ( HHcy)-induced in-flammation and atherosclerosis .METHODS:ApoE-/-mice were fed regular diet , high fat ( HF) diet or HF plus high methionine (HM) diet for 10 weeks.NLRP3 shRNA or scramble shRNA viral suspension was injected twice at the 2nd and the 6th weeks after HFHM treatment.The whole aortas and aortic root sections were stained with Oil Red O for atherosclerotic lesion .Plasma lipids, ho-mocysteine ( Hcy) , IL-1βand IL-18 levels were measured .We also examined the effect of Hcy on NLRP 3 inflammasomes activation in THP-1 differentiated macrophages in the presence or absence of NLRP 3 siRNA, caspase-1 inhibitor Z-WEHD-FMK, or antioxidant N-acetyl-L-cysteine ( NAC) .RESULTS:HFHM treatment induced HHcy in ApoE-/-mice.Increased plasma levels of IL-1βand IL-18, aggravated macrophage infiltration into atherosclerotic lesion , and accelerated development of atherosclerosis were detected in HHcy mice, which were associated with the activation of NLRP 3 inflammasomes.Silencing the NLRP3 gene significantly suppressed NLRP3 inflammasomes activation , reduced plasma levels of proinflammatory cytokines , attenuated macrophage infiltration , and improved HHcy-induced atherosclerosis .Moreover, we found that Hcy activated NLRP3 inflammasomes and promoted subsequent production of IL-1βand IL-18 in macrophages, which were blocked by NLRP3 gene silencing, Z-WEHD-FMK, or NAC.CONCLUSION:These data suggest that the activation of NLRP 3 inflammasomes contributes to HHcy-induced inflammation and atherosclerosis .Hcy activates NLRP3 inflammasomes in reactive oxygen species dependent pathway in macrophages .
作者: 刊期: 2016年第08期
AIM:To investigate the relationship between polyamine metabolism and hypoxia /ischemia ( H/I)-induced cell apoptosis and to determine the mechanisms by which exogenous spermine protects cell apoptosis against AMI in rats .METHOD:The left anterior de-scending coronary artery ( LAD) of the Wistar rats were ligated , and neonatal rat cardiomyocytes were placed under hypoxic conditions for 24 h to establish the model of AMI (or H/I).Exogenous spermine was administered by intraperitoneal injection (2.5 mg/kg daily for 7 days) in vitro and subjected to the cell medium at 5μmol/L as a pre-treatment therapy.RESULTS:AMI (or H/I) induced an increase in polyamine catabolized enzyme SSAT and a decrease in polyamine biosynthesis enzyme ODC , which result in endogenous spermine and spermidine decrease and putrescine increase .At the same time, AMI ( or H/I) lowered cardiac function , increased cTnI and CK-MB concentrations , aggravated myocardial infarct size , cardiomyocyte damage and apoptosis , raised ROS generation , increased the expression of cleaved caspase-3, cleaved caspase-9 and endoplasmic reticulum stress (ERS)-related proteins, promoted the release of cytochrome C and mPTP opening , down-regulated Bcl-2 expression and the phosphorylation of ERK 1/2, PI3K, Akt and GSK-3β, and activated PERK and eIF 2αphosphorylation .Spermine pre-treatment reversed the above-motioned changes .CONCLUSION:AMI ( or H/I ) could induce cardiomyocyte apoptosis and polyamine metabolism disorder .Exogenous spermine attenuates cardiac injury through scavenging the ROS and inhibiting mPTP opening and ERS injury .These findings provide a novel target for the prevention of apoptosis in the setting of AMI .
作者: 刊期: 2016年第08期
AIM:We investigated how AT 1-R stimulated by mechanical stresses induces cardiac fibrosis .METHODS:We produced in vivo cardiac pressure overload model in angiotensinogen knockout ( ATG-/-) mice and in vitro mechanically-stretched cell model in cultured neonatal cardiac cells of ATG-/-mice both lack the participation of Ang II .RESULTS: Pressure overload for 4 weeks in ATG-/-mice induced myocardial hypertrophy accompanied by the significant interstitial fibrosis , however , the TGF-β, a key regulatory factor of fibrosis, was not significantly increased in these ATG-/-mice.Meanwhile, the inhibitor for AT1-R significantly inhibited mechani-cal stress-induced cardiac fibrosis in these ATG-/-models whereas inhibition of TGF-βdid not.CONCLUSION:The results showed that mechanical stress-induced fibrotic responses through AT 1-R required the phosphorylation of Smad 2 but not the involvement of TGF-β.
作者: 刊期: 2016年第08期
目的:动物实验表明高盐摄入可降低循环及肾脏中肾胺酶的表达水平。本研究拟探讨钠、钾摄入对成人血清和尿中肾胺酶表达的影响。方法:42名(28~65岁)来自中国北方农村的受试者参与了这项研究。所有受试者依次接受低盐饮食7 d(氯化钠3 g/d),高盐饮食7 d(氯化钠18 g/d),高盐补钾饮食7 d(氯化钠18 g+氯化钾4.5 g/d)。血清及尿中肾胺酶水平用ELISA试剂盒进行检测。结果:低盐饮食期,血清中肾胺酶水平较基线期显著升高。低盐转向高盐饮食期时,血清肾胺酶水平随之下降,但同时给予补钾后,可阻止高盐所致的肾胺酶水平下降。尿中肾胺酶水平在高盐饮食期显著高于低盐期。高盐补钾期,尿中肾胺酶水平与单纯高盐期相比无显著差异,但显著高于低盐饮食期。24 h尿钠排泄与血清中肾胺酶水平呈负相关,与尿中肾胺酶水平呈正相关。结论:饮食中钠、钾含量的变化可显著影响中国人血清及尿中肾胺酶的表达水平。
作者:吕永波;汪洋;牟建军 刊期: 2016年第08期
目的:探讨白藜芦醇对异丙肾上腺素诱导的心肌细胞肥大的保护作用及对心肌肥大时内质网应激相关因子GRP78和GRP94表达的影响。方法:利用异丙肾上腺素诱导乳鼠心肌细胞建立心肌肥大细胞模型,将心肌细胞分为正常对照组、模型组(加入异丙肾上腺素0.3 mg/L作用48 h),白藜芦醇+异丙肾上腺素组(加入异丙肾上腺素0.3 mg/L和白藜芦醇11.4 mg/L作用48 h)和白藜芦醇对照组(加入白藜芦醇11.4 mg/L)。检测心肌细胞表面积和心肌肥大标志物ANP表达评价心肌细胞肥大程度,检测细胞培养液中乳酸脱氢酶( LDH)活性和丙二醛( MDA)含量; Western blot 分析GRP78和GRP94的蛋白表达。结果:模型组与正常组比较,异丙肾上腺素作用心肌细胞48 h诱导心肌细胞肥大,内质网应激相关因子GRP78和GRP94蛋白表达均增高;白藜芦醇+异丙肾上腺素组与模型组比较,白藜芦醇(11.4 mg/L)干预可以有效抑制异丙肾上腺素诱导的细胞肥大,同时降低GRP78和GRP94的蛋白表达,减少细胞培养液中乳酸脱氢酶LDH和MDA的释放。结论:白藜芦醇通过抑制内质网应激相关因子GRP78和GRP94表达,减轻自由基生成发挥对心肌肥大的保护作用。
作者:王珺;肖薇;李波;金莉;王国忠;林岩 刊期: 2016年第08期