间歇低压低氧预处理对心肌缺血／再灌注损伤及ZFP580表达的影响

目的：探讨间歇性低压低氧（IHH）预处理对大鼠心肌缺血／再灌注（I/R）损伤后血清中心肌酶、心肌梗死的影响及锌指核转录因子ZFP580发挥的作用。方法：32只雄性Wistar大鼠随机分为IHH预处理组和常氧对照组（n=16）。IHH组大鼠置于模拟海拔高度为5000m的低压氧舱中,每天6h,持续42d。两组大鼠经结扎冠状动脉左前降支建立心肌I/R损伤模型后,检测血清中乳酸脱氢酶（LDH）活性及肌酸磷酸肌酶同功酶（CK-MB）浓度,并利用Western blot方法观察各组大鼠心肌组织中ZFP580的表达情况。每组另外8只大鼠经心肌酞菁蓝-TIC染色后比较心肌梗死面积。培养大鼠H9c2心肌细胞,利用慢病毒介导的基因转染实验获得高表达ZFP580的心肌细胞,并进行心肌细胞模拟缺血／再灌注（SI/）损伤实验。利用Annexin V-PE／7-AAD柒色及流式细胞术检测H9c2心肌细胞的凋亡情况。结果：IHH预处理能明显减少心肌I／R损伤后IDH、CK-MB漏出至血清,并明显缩小心肌梗死面积。大鼠经IHH预处理后心肌组织中ZFP580的表达上调,IHH预处理明显上调心肌L／R损伤后心肌组织中ZFP580的表达。高表达ZFP580的H9c2心肌细胞在STIR损伤后细胞凋亡率明显下降。结论：IHH预处理对于心肌I／R损伤具有明显细胞保护作用,其上调的ZFPS80表达具有减少心肌细胞凋亡的作用,ZFP580可能作为心肌细胞内源性抗凋亡分子之一,参与IHH预处理抗心肌I／R损伤的过程。     

积雪草对早期糖尿病肾病大鼠TGF-β1表达及相关下游信号的影响

目的：通过研究积雪草（CA）对早期糖尿病肾病大鼠转化生长因子β₁（TGF-β₁）表达及相关下游信号的影响,阐明积雪草防治早期糖尿病肾病（DN）的分子机制。方法：60只雄性SD大鼠,按体重随机分为假手术组（n=10）和造模组（n=50）。造模组大鼠进行右肾切除术,1周后给以腹腔注射链脲佐菌素（STZ）30 mg/kg,连续给3 d;72 h后测血糖,以 ≥ 16.7 mmol/L,尿糖+++以上及尿量大于对照组的50%为DN模型成模标准。假手术组进行右肾被膜损伤,并注射相应量生理盐水。造模组通过灌胃给药,分为：DN模型组（模型组）、DN+福辛普利组（蒙组1.6 mg/kg·d）、DN+积雪草高剂量组（高剂量组16.8 mg/kg·d）、DN+积雪草中剂量组（中剂量组11.2 mg/kg·d）和DN+积雪草低剂量组（低剂量组5.6 mg/kg·d）（n=10）,连续给药16周,每日上午1次灌胃。利用实时荧光定量PCR和Western blot分别检测肾组织中TGF-β₁、TβR1、TβR2、Smad2/3、p-Smad2/3及Smad7 mRNA和蛋白的表达。结果：与假手术组相比,DN组TGF-β₁、TβR1、TβR2、Smad2/3 mRNA和蛋白表达及Smad2/3蛋白的磷酸化水平显著增加（P<0.05）、Smad7 mRNA和蛋白表达明显减少（P<0.05）,而福辛普利和高剂量积雪草能倒转DN引起的TGF-β₁、TβR1、TβR2、Smad2/3 mRNA和蛋白表达增加（P<0.05）及Smad7 mRNA和蛋白表达降低（P<0.05）。结论：积雪草可能通过调控TGF-β₁/Smad信号通路起到防治DN的作用。     

巨噬细胞亚型转变在大鼠肾脏缺血/再灌注损伤中的作用

目的：探讨巨噬细胞在大鼠肾脏缺血/再灌注损伤过程中的亚型转变及意义。方法：将30只雄性SD大鼠随机分成假手术组（Sham,n=6）和缺血/再灌组（IRI,夹闭肾动脉45 min,n=24）。IRI组分别于术后0、6、24和72 h取肾组织,每个时相组6只大鼠。用HE染色观察肾组织损伤程度;免疫组化染色检测细胞增殖核抗原（PCNA）的表达;实时定量RT-PCR检测巨噬细胞移动抑制因子（MIF） mRNA的表达;免疫组织荧光染色检测MIF、单核巨噬细胞趋化蛋白-1（MCP-1）以及活化巨噬细胞标志物CD68的表达,流式细胞分析检测巨噬细胞M1和M2亚型的分布特征。结果：病理结果显示大鼠肾局部损伤情况和炎症细胞浸润程度在24 h时最为严重,之后逐渐恢复。PCNA在再灌后表达明显增加,6 h达峰值,72 h表达下降。相比于正常组,再灌组大鼠肾组织中MIF的mRNA和蛋白表达明显升高;MCP-1表达则在6 h达峰值,随后下降;而CD68阳性的巨噬细胞数量明显增加,24 h达峰值,72 h表达下降。更进一步研究发现缺血/再灌注6 h时,M1亚型分布达最高值;之后随着缺血/再灌注时间延长,M1亚群相对含量开始下调,M2随之升高。结论：在肾脏缺血/再灌注早期,M1巨噬细胞介导的组织损伤发挥主要作用,随后M2型表达逐渐上调,并通过促进细胞增殖修复肾组织损伤。     

锌指蛋白ZFP580在全反式维甲酸调节大鼠血管平滑肌细胞迁移中的作用及机制

目的:探讨锌指基因ZFP580在全反式维甲酸(ATRA)调节VSMCs迁移功能中的作用及其机制。方法:分离,培养并鉴定大鼠主动脉VSMCs;分别予以0、5、10、20 μmol/L ATRA刺激VSMCs 24h,以0 μmol/L ATRA组为对照组,观察不同溶度ATRA刺激不同时间对VSMCs迁移能力的影响或给予0、20 μmol/L ATRA刺激VSMCs 24、48、72h,观察ATRA刺激不同时间对VSMCs迁移能力的影响;QPCR及Western blot检测ATRA刺激VSMCs后ZFP580的mRNA和蛋白表达变化;应用ERK抑制剂PD98059抑制ERK的蛋白表达,观察ERK信号蛋白表达变化对ATRA刺激后ZFP580蛋白表达的影响;腺病毒转染技术获得过表达或低表达ZFP580的VSMCs,QPCR及Western blot检测MMP-2和MMP-9、ZFP580蛋白和mRNA表达水平。结果:分离的VSMCs在培养10d后,免疫荧光显示平滑肌细胞特异性标记物SM22α抗体阳性。与对照组相比,5、10、20 μmol/L ATRA预刺激分别降低了32%、43%和59%的VSMCs迁移能力;20 μmol/L ATRA刺激VSMCs与对照组相比,在24、48、72h分别降低49%、36%和22%细胞迁移能力。ZFP580的mRNA和蛋白表达随着ATRA刺激溶度的增加和刺激时间的延长而升高。ERK在ATRA刺激15min即显著升高,运用ERK抑制剂PD98059(20 μmol/L)预处理抑制ERK蛋白表达并降低了ATRA诱导ZFP580的蛋白表达。过表达ZFP580降低MMP-2和MMP-9的mRNA和蛋白表达,反之,低表达ZFP580则上调了MMP-2和MMP-9的mRNA和蛋白表达。结论:ATRA可通过ERK信号通路上调ZFP580的表达,而ZFP580通过调控MMP-2和MMP-9的表达参与ATRA对VSMCs迁移的抑制作用。     

贯叶连翘提取物对小鼠免疫性心肌炎心肌纤维化的影响及其机制*

目的:研究贯叶连翘提取物(HPE)对小鼠实验性免疫性心肌炎心肌纤维化(MFEAM)的影响。方法:利用猪心肌肌球蛋白免疫易感鼠系,建立小鼠MFEAM模型,将MFEAM模型组小鼠随机分为: MFEAM模型组(n=14)、HPE100 mg/kg组(n=13)、HPE 40 mg/kg组(n=13)、Cap 50 mg/kg对照组(n=13)。各组药物每次均分别以0.4 ml生理盐水溶解,采用灌胃给药方式,每天2次,共60 d;正常对照组(n=10),MFEAM模型组按上述方法同体积同疗程给予生理盐水。通过观察小鼠一般情况,测定心脏重量、脾脏重量与体重之比,检测小鼠血清中I型前胶原N端前肽(PINP)、III型前胶原N端前肽(PIIINP)含量及转化生长因子-β1(TGF-β1)浓度,Masson染色显微镜观察心肌纤维化(MF)程度及胶原容积分数(CVF)测定,Western blot检测心肌TGF-β1蛋白表达。结果:MFEAM模型组小鼠血清中TGF-β1浓度及PINP、PIIINP含量显著升高,MF程度及CVF增加,心肌TGF-β1蛋白表达上调,与正常组比较差异有显著性意义(P＜0.05或P＜0.01);而HPE 40 mg/kg、100 mg/kg及Cap对照组血清PINP、PIIINP含量及TGF-β1浓度均减少,不同HPE或Cap剂量显著改善或降低MFEAM模型小鼠MF程度及CVF,不同程度下调心肌TGF-β1蛋白表达水平,与MFEAM模型组比较差异有显著性意义(P＜0.05或P＜0.01)。结论:HPE对MF有治疗作用,可能与其减少胶原蛋白沉积,抑制TGF-β1信号通路有关。     

姜黄素类似物L6H4对2型糖尿病大鼠肾脏的保护作用

目的：探讨姜黄素类似物L6H4对2型糖尿病大鼠肾脏的保护作用及机制。方法：24只SPF级雄性SD大鼠,随机分成3组（n=8）：对照组（NC组）、糖尿病组（DM组）和糖尿病治疗组（DT组）,采用高脂饮食加腹腔注射低剂量链脲佐菌素诱导2型糖尿病大鼠模型。DT组按0.2 mg/kg·d剂量的L6H4灌胃8周。治疗结束后测24 h尿蛋白、空腹血糖（FBG）、甘油三酯（TG）、血肌酐（Scr）、血尿素氮（BUN）、尿酸（UA）。采用光镜和透射电镜观察大鼠肾脏的形态学改变;用免疫组化法测定大鼠肾脏组织转化生长因子-β1（TGF-β1）、纤维粘连蛋白（FN）、四型胶原（Col-IV）的表达水平。结果：DM组大鼠24 h尿蛋白、FBG、TG、Scr、BUN均明显升高（P<0.01）,肾小球体积增大、不规则,弥漫性系膜基质增多,伴基底膜不同程度的增生肥厚及足突融合现象;肾组织的TGF-β1、FN、Col-IV表达水平明显增加（P<0.05）。经L6H4治疗后,DT组的24 h尿蛋白、FBG、TG、Scr、BUN水平明显下降（P<0.01）,大鼠肾小球形态较规则,系膜区基质明显减少,足细胞肿胀、融合现象减轻;肾组织的TGF-β1、FN、Col-IV表达明显减少（P<0.05）。结论：L6H4可能通过下调TGF-β1的表达,抑制FN、Col-IV的大量分泌,减轻细胞外基质的沉积,从而起到保护2型糖尿病大鼠肾脏的作用。     

高糖诱导的大鼠原代心肌细胞损伤对程序性坏死的影响及其机制*

目的: 探讨程序性坏死在高糖诱导的大鼠原代心肌细胞损伤中的变化及可能机制。方法: 原代大鼠心肌细胞随机分为4组(n=9):正常对照组(Control,5.5 mmol/L葡萄糖培养心肌细胞48 h)、高糖组(HG,30 mmol/L葡萄糖培养心肌细胞48 h)、HG+Nec-1(30 mmol/L葡萄糖+100 μmol/L程序性坏死关键蛋白RIP1抑制剂Nec-1共同培养心肌细胞48 h)组、高渗组(HPG,5.5 mmol/L葡萄糖+24.5 mmol/L甘露醇共同培养心肌细胞48 h)。MTT法检测各组心肌细胞活力,DHE荧光染色检测细胞氧化应激水平,ELISA法检测心肌细胞TNF-α、IL-6及IL-1β水平,Real-time PCR和Western blot分别检测各组程序性坏死关键蛋白RIP1、RIP3、MLKL mRNA和蛋白水平的表达情况。结果: 与Control组相比,HG组心肌细胞活力明显降低(P＜0.01),氧化应激水平明显增高(P＜0.01),TNF-α、IL-6及IL-1β水平升高明显(P＜0.01),RIP1、RIP3、MLKL mRNA及蛋白水平表达均明显升高(P＜0.05);与HG组相比,HG+Nec-1组心肌细胞活力明显升高(P＜0.01),氧化应激水平明显下降(P＜0.01),TNF-α、IL-6及 IL-1β水平明显降低(P＜0.01), RIP1、RIP3、MLKL mRNA及蛋白水平表达均下降(P＜0.05)。结论: 高糖诱导的原代大鼠心肌细胞损伤可引起程序性坏死的发生;抑制程序性坏死可减轻细胞损伤的机制,可能与抑制氧化应激、减轻炎症反应有关。     

厄贝沙坦对抗糖尿病大鼠心肌纤维化作用及机制

目的：观察厄贝沙坦对抗糖尿病大鼠心肌纤维化的作用,并分析细胞外调节信号激酶（ERK）通路在其中的作用。方法：健康雄性SD大鼠32只,随机分成两组：正常对照组（CON,n=10）,实验组（n=22）。实验组糖尿病造模成功20只,随机分为2组（n=10）：糖尿病组（DM）、厄贝沙坦+糖尿病组（Ir+DM）。8周后测定空腹血糖（FBG）水平,计算各组大鼠体重（BW）、心体比（H/B）和左室重量指数（LVWI）;Masson染色观察心肌形态及纤维化的发生;ELISA检测心肌组织胶原Ⅰ（colⅠ）、胶原Ⅲ（colⅢ）含量;Western blot检测心肌组织ERK1/2、p-ERK1/2蛋白的表达。结果：与CON组相比,DM组大鼠FBG水平、H/B、LVWI显著升高,体重显著减轻,colⅠ、colⅢ含量显著增加,心肌组织p-ERK1/2蛋白表达及p-ERK1/2/ERK1/2比值增加（P<0.05,P<0.01）,ERK1/2无明显变化。Masson染色显示DM组心肌胶原纤维粗大,交织成网状,排列分布不均,沉积增多。与DM组大鼠相比,厄贝沙坦干预后大鼠体重明显增加,H/B、LVWI、心肌组织colⅠ、colⅢ含量明显降低（P<0.05,P<0.01）,p-ERK1/2蛋白表达及p-ERK1/2/ERK1/2比值降低（P<0.01）,且心肌形态改善明显。结论：糖尿病可诱导心肌纤维化的发生,厄贝沙坦可通过抑制ERK的活化减轻糖尿病诱导的心肌纤维化损伤。     

辛伐他汀对大鼠糖尿病所致心肌细胞凋亡的影响及其机制

目的：探讨辛伐他汀对糖尿病所致心肌损伤的保护作用及可能机制。方法：24只SD大鼠（180~220） g随机分为对照组（control组,n=8）和模型组（n=16）,模型组给予链脲佐菌素（STZ）腹腔注射建立糖尿病模型,然后随机将模型组分为糖尿病组（DM组,n=8）和糖尿病+辛伐他汀组（DM+S组,n=8）,DM+S组给予辛伐他汀40 mg/（kg·d）灌胃四周,其余两组给予的等量生理盐水。实验结束后,取心脏,分光光度测定法测定大鼠心肌组织脂质过氧化物丙二醛（MDA）含量、超氧化物歧化酶（SOD）的活性,HE染色观察大鼠心肌病理学改变,TUNEL法检测大鼠心肌细胞凋亡,免疫组织化学法测定大鼠p53的表达;Western blot检测心肌组织p53,p53-phospho-serine15,Bax,Bcl-2等蛋白的表达。结果：①与对照组比较,DM组大鼠心肌组织MDA含量显著升高（P<0.01）,SOD活性明显下降（P<0.01）,与DM组比较,DM+S组大鼠SOD活性显著增加（P<0.01）,MDA含量显著下降（P<0.01）。②HE染色结果表明,与对照组比较,DM组大鼠心肌细胞排列紊乱,结构不清晰,有大量炎性细胞浸润;与DM组比较,DM+S组的心肌细胞结构明显改善。③ TUNEL细胞凋亡检测结果表明,与control组相比,DM组心肌凋亡细胞阳性率显著增加（P<0.01）,给予辛伐他汀后细胞凋亡明显减少（P<0.01）;④免疫组织学检测结果显示,与对照组比较,DM组p53表达量显著增加,且p53在细胞质和细胞核中均有表达（P<0.01）;与DM组比较,DM+S组p53表达量明显下降,p53在细胞质和核中均有表达,但核内表达量减少（P<0.01）。⑤ Western blot检测结果表明,与对照组比较,DM组大鼠p53,p53-Phospho-Serine15,Bax表达量显著升高（P<0.01）,Bcl-2表达量减少（P<0.01）;与DM组比较,DM+S组p53（P<0.01）,p53-Phospho-Serine15（P<0.01）,Bax （P<0.05）表达量显著下降,Bcl-2（P< 0.05）表达量显著增加。结论：辛伐他汀通过改善心肌结构异常、抑制氧化应激和心肌细胞凋亡对糖尿病导致的心肌损伤起到保护作用,其机制与p53介导的细胞凋亡通路相关蛋白的调控有关。     

熊果酸对糖尿病小鼠心肌病变的作用及其机制

目的：研究熊果酸对高脂饮食结合小剂量链脲佐菌素（STZ）诱导的糖尿病小鼠心肌病的影响,探讨其可能的作用机制。方法：雄性ICR小鼠30只,随机分为对照组（n=10）和造模组（n=20）,对照组和造模组分别以普通饲料及高脂饲料饲养,连续6周。造模组腹腔注射STZ连续5 d,对照组腹腔注射相应溶剂,9 d后测空腹血糖（FBG）,高于11.1 mmol/L视为糖尿病模型。20只成功造模小鼠随机分为模型组和熊果酸组（n=10）。各组连续灌胃给药（熊果酸100 mg/kg或相应溶剂）8周。测定FBG、体重、全心重和左心室重,计算心脏质量指数（HMI）和左室质量指数（LVMI）;测定血清肌酸激酶（CK）、乳酸脱氢酶（LDH）水平;测定心肌组织超氧化物歧化酶（SOD）活力和丙二醛（MDA）含量;HE染色观察心肌病理改变;免疫组化法测定NOD样受体蛋白3（NLRP3）、白介素-1β（IL-1β）的蛋白质表达。结果：与正常组比较,模型组HMI、LVMI、FBG、CK、LDH、MDA水平显著升高;SOD活力显著降低。HE染色显示,模型组小鼠心肌纤维排列紊乱,细胞水肿、肥大,细胞间质大量炎性细胞浸润;免疫组化显示,模型组小鼠心肌组织NLRP3和IL-1β蛋白质表达显著增加;熊果酸组小鼠的上述变化明显改善。结论：熊果酸对高脂饲料结合小剂量链脲佐菌素诱导的糖尿病小鼠心肌损伤有明显的改善作用,其机制与抑制NLRP3炎症小体活化,减少IL-1β生成,减轻心肌组织炎性损伤有关。     

miR-148a在5-aza诱导间充质干细胞心肌样分化中的调控作用及机制

目的：探讨miR-148a在5-aza诱导人骨髓间充质（hMSCs）成心肌样分化中的表达及miR-148a对hMSCs体外成心肌样分化的生物学作用。方法：免疫荧光检测5-aza诱导hMSCs分化后心肌细胞特异性标志物α-MHC表达水平;qRT-PCR和Western blot分别检测miR-148a和DNMT1在hMSCs成肌样分化中的表达水平。利用Lipofectamine TM 2000将miR-148a mimics和miR-148a inhibitor分别瞬时转染hMSCs,Western blot检测心肌细胞特异性标志物α-MHC的蛋白表达水平。利用生物信息学技术预测miR-148a的靶基因结合位点利用双荧光素酶报告基因系统鉴定其对靶基因3'UTR的结合序列。通过DNMT1 shRNA和miR-148a inhibitors共转到hMSCs中,研究miR-148a在hMSCs成心肌样分化中的调控作用。结果：hMSCs经5-aza诱导分化后,心肌细胞特性标志物α-MHC蛋白水平明显上调。miR-148a在hBMSCs成肌样分化中显著性增加（P<0.01）,DNMT1表达水平显著降低。过表达miR-148a能提高hBMSC中心肌细胞特异性标志物α-MHC表达水平,而抑制miR-148a则能降低其水平（P<0.01）。DNMT1沉默可以阻断miR-148a对hMSCs的诱导成肌样分化作用。结论：miR-148a在hMCCs成肌样分化中表达上调,通过靶定和调控DNMT1基因的表达,并对hMSCs心肌向分化具有正向调控作用。     

Downregulation of p300/CBP-associated factor inhibits cardiomyocyte apoptosis via suppression of NF-κB pathway in ischaemia/reperfusion injury rats

Cardiomyocyte apoptosis is the main reason of cardiac injury after myocardial ischaemia-reperfusion (I/R) injury (MIRI), but the role of p300/CBP-associated factor (PCAF) on myocardial apoptosis in MIRI is unknown. The aim of this study was to investigate the main mechanism of PCAF modulating cardiomyocyte apoptosis in MIRI. The MIRI model was constructed by ligation of the rat left anterior descending coronary vessel for 30 min and reperfusion for 24 h in vivo. H9c2 cells were harvested after induced by hypoxia for 6 h and then reoxygenation for 24 h (H/R) in vitro. The RNA interference PCAF expression adenovirus was transfected into rat myocardium and H9c2 cells. The area of myocardial infarction, cardiac function, myocardial injury marker levels, apoptosis, inflammation and oxidative stress were detected respectively. Both I/R and H/R remarkably upregulated the expression of PCAF, and downregulation of PCAF significantly attenuated myocardial apoptosis, inflammation and oxidative stress caused by I/R and H/R. In addition, downregulation of PCAF inhibited the activation of NF-κB signalling pathway in cardiomyocytes undergoing H/R. Pretreatment of lipopolysaccharide, a NF-κB pathway activator, could blunt these protective effects of PCAF downregulation on myocardial apoptosis in MIRI. These results highlight that downregulation of PCAF could reduce cardiomyocyte apoptosis by inhibiting the NF-κB pathway, thereby providing protection for MIRI. Therefore, PCAF might be a promising target for protecting against cardiac dysfunction induced by MIRI.     

miR-34a Modulates Angiotensin II-Induced Myocardial Hypertrophy by Direct Inhibition of ATG9A Expression and Autophagic Activity

Cardiac hypertrophy is characterized by thickening myocardium and decreasing in heart chamber volume in response to mechanical or pathological stress, but the underlying molecular mechanisms remain to be defined. This study investigated altered miRNA expression and autophagic activity in pathogenesis of cardiac hypertrophy. A rat model of myocardial hypertrophy was used and confirmed by heart morphology, induction of cardiomyocyte autophagy, altered expression of autophagy-related ATG9A, LC3 II/I and p62 proteins, and decrease in miR-34a expression. The in vitro data showed that in hypertrophic cardiomyocytes induced by Ang II, miR-34a expression was downregulated, whereas ATG9A expression was up-regulated. Moreover, miR-34a was able to bind to ATG9A 3′-UTR, but not to the mutated 3′-UTR and inhibited ATG9A protein expression and autophagic activity. The latter was evaluated by autophagy-related LC3 II/I and p62 levels, TEM, and flow cytometry in rat cardiomyocytes. In addition, ATG9A expression induced either by treatment of rat cardiomyocytes with Ang II or ATG9A cDNA transfection upregulated autophagic activity and cardiomyocyte hypertrophy in both morphology and expression of hypertrophy-related genes (i.e., ANP and β-MHC), whereas knockdown of ATG9A expression downregulated autophagic activity and cardiomyocyte hypertrophy. However, miR-34a antagonized Ang II-stimulated myocardial hypertrophy, whereas inhibition of miR-34a expression aggravated Ang II-stimulated myocardial hypertrophy (such as cardiomyocyte hypertrophy-related ANP and β-MHC expression and cardiomyocyte morphology). This study indicates that miR-34a plays a role in regulation of Ang II-induced cardiomyocyte hypertrophy by inhibition of ATG9A expression and autophagic activity.     

Downregulation of p300/CBP‐associated factor inhibits cardiomyocyte apoptosis via suppression of NF‐κB pathway in ischaemia/reperfusion injury rats

Cardiomyocyte apoptosis is the main reason of cardiac injury after myocardial ischaemia‐reperfusion (I/R) injury (MIRI), but the role of p300/CBP‐associated factor (PCAF) on myocardial apoptosis in MIRI is unknown. The aim of this study was to investigate the main mechanism of PCAF modulating cardiomyocyte apoptosis in MIRI. The MIRI model was constructed by ligation of the rat left anterior descending coronary vessel for 30 min and reperfusion for 24 h in vivo. H9c2 cells were harvested after induced by hypoxia for 6 h and then reoxygenation for 24 h (H/R) in vitro. The RNA interference PCAF expression adenovirus was transfected into rat myocardium and H9c2 cells. The area of myocardial infarction, cardiac function, myocardial injury marker levels, apoptosis, inflammation and oxidative stress were detected respectively. Both I/R and H/R remarkably upregulated the expression of PCAF, and downregulation of PCAF significantly attenuated myocardial apoptosis, inflammation and oxidative stress caused by I/R and H/R. In addition, downregulation of PCAF inhibited the activation of NF‐κB signalling pathway in cardiomyocytes undergoing H/R. Pretreatment of lipopolysaccharide, a NF‐κB pathway activator, could blunt these protective effects of PCAF downregulation on myocardial apoptosis in MIRI. These results highlight that downregulation of PCAF could reduce cardiomyocyte apoptosis by inhibiting the NF‐κB pathway, thereby providing protection for MIRI. Therefore, PCAF might be a promising target for protecting against cardiac dysfunction induced by MIRI.     

caspase抑制剂z-VAD-fmk对阿霉素损伤乳鼠心肌细胞calumenin、caspase-3、GRP78及GRP94表达的影响

目的：研究细胞凋亡限速酶caspase广谱抑制剂z-VAD-fmk对阿霉素损伤心肌细胞calumenin、caspase-3、GRP78及GRP94表达的影响,探讨心肌细胞网腔钙结合蛋白与内质网应激及心肌细胞凋亡是否存在相互调控关系。方法：原代培养乳鼠心肌细胞实验分为3组：对照组（正常细胞）、阿霉素组（3 mg/L阿霉素+心肌细胞）、Z-VAD-fmk组（3 mg/L阿霉素+ 0.1μmol/L Z-VAD-fmk +心肌细胞）,每组细胞设3个复孔,分别处理后置37℃、CO₂培养箱中培养24 h阿霉素组、z-VAD-fmk组。采用免疫组化方法检测培养乳鼠心室肌细胞α-SMA蛋白。采用Westernblot技术检测各组心肌细胞Calumenin、内质网应激伴侣蛋白GRP78、GRP94及caspase-3表达。结果：与对照组相比较,阿霉素组心肌细胞calumenin表达明显减少（P < 0.01）,GRP78、GRP94及caspase-3表达增加（P < 0.01）。与阿霉素组相比较,z-VAD-fmk组心肌细胞calumenin表达增加（P < 0.01）,而GRP7,GRP94及caspase-3减少（P < 0.01）。结论：caspase广谱抑制剂z-VAD-fmk增加阿霉素损伤心肌细胞calumenin表达进而缓解内质网应激。     

The protective effects of N-n-butyl haloperidol iodide on myocardial ischemia-reperfusion injury in rats by inhibiting Egr-1 overexpression.

AIMS: Our previous studies have shown that N-n-butyl haloperidol iodide (F(2)) can antagonize myocardial ischemia/reperfusion (I/R) injury by blocking intracellular Ca(2+) overload. The present study is to test the hypothesis that the protective effects of F(2) on myocardial I/R injury is mediated by downregulating Egr-1 expression. METHODS: The Sprague-Dawley rat myocardial I/R model and cardiomyocyte hypoxia/reoxygenation (H/R) model were established. With antisense Egr-1 oligodeoxyribonucleotide (ODN), the relationship between Egr-1 expression and myocardial I/R injury was investigated. Hemodynamic parameters, myeloperoxidase (MPO), cardiac troponin I (cTnI) and tumor necrosis factor-alpha (TNF-alpha) were measured to assess the degree of injury and inflammation of myocardial tissues and cells. Egr-1 mRNA and protein expressions were examined by Northern-blot and Western-blot analyses. RESULTS: Treatment with antisense Egr-1 ODN significantly reduced Egr-1 protein expression and attenuated injury of myocardial tissues and cells. Meanwhile, treatment with F(2) significantly inhibited the overexpression of Egr-1 mRNA and protein in myocardial tissues and cells. Consistent with downregulation of Egr-1 expression by F(2), inflammation and other damages were significantly relieved evidenced by the amelioration of hemodynamics, the reduction in myocardial MPO activity as well as the decrease in leakage of cTnI and release of TNF-alpha from cardiomyocyte. CONCLUSIONS: These results suggested that the overexpression of Egr-1 was causative in myocardial I/R or H/R injury, and F(2) could protect myocardial tissues and cells from I/R or H/R injury, which was largely due to the inhibition of Egr-1 overexpression.