大鼠骨髓间充质细胞经SDF-1预处理后移植对急性心肌梗死的治疗效果

目的 探讨大鼠骨髓间充质细胞(BMSC)经基质细胞衍生因子-1(SDF-1)预处理后移植对急性心肌梗死(AMI)的治疗效果.方法 (1)全骨髓贴壁法培养大鼠BMSC;逆转录聚合酶链反应(RT-PCR)和免疫组织化学法检测BMSC趋化因子受体(CXCR4)基因的表达;将BMSC分别与10和100μg/L的SDF-1作用24 h后,在无氧、无血清条件下培养6 h,流式细胞仪和末端标记(TUNEL)法检测细胞凋亡率.(2)建立大鼠急性心肌梗死模型,将经100μg/L SDF-1预处理的BMSC和未经处理的BMSC植入大鼠梗死心肌周边,2周后采用超声心动图观察心脏功能的变化.结果 BMSC表达CXCR4基因;在无氧和无血清条件下,经SDF-1预处理的BMSC凋亡率与对照组比较明显降低(P<0.05),而经100 μg/L SDF-1预处理的BMSC凋亡率最低.成功建立大鼠急性心肌梗死模型;与未经处理的BMSC移植比较,经SDF-1预处理的BMSC移植后改善心肌梗死大鼠的心功能作用更为明显(P<0.05).结论 用SDF-1预处理大鼠BMSC能抑制其在无氧和无血清条件下的凋亡.用SDF-1预处理BMSC能增强其移植后治疗大鼠急性心肌梗死的效果.     

粒细胞集落刺激因子联合携带肝细胞生长因子基因的BMSCs移植对心肌梗死大鼠血管重建的影响

目的研究粒细胞集落刺激因子(granulocyte colony stimulating factor,G-CSF)联合携带肝细胞生长因子(hepatocyte growth factor,HGF)基因的BMSCs移植对心肌梗死大鼠血管重建的影响,初步探讨作用机制。方法取3周龄雄性SD大鼠骨髓分离培养BMSCs,取第3代BMSCs以携带HGF基因的5型复制缺陷型腺病毒(Ad-HGF)感染。成年雄性SD大鼠44只,体重200～250 g,结扎左冠状动脉建立心肌梗死模型。造模4周后心脏超声检查,以左室短轴缩短率(shorting fraction,FS)<30%作为造模成功标准。取其中12只大鼠,于梗死心肌边缘注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL),2、7、14 d后用Western blot方法检测大鼠体内HGF蛋白的表达。将其余32只大鼠随机分为4组,每组8只:对照组注射0.1 mL生理盐水;G-CSF组注射0.1 mL生理盐水并于腹腔注射G-CSF 100μg(/kg.d)共5 d;HGF组注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL);联合治疗组注射0.1 mL Ad-HGF感染的BMSCs(5×107个/mL)并于腹腔注射G-CSF 100μg/(kg.d)共5 d。细胞移植后2周,行心功能和血流动力学检测,然后处死大鼠取心肌组织行免疫荧光双染后激光共聚焦显微镜下评价血管生成情况,Western blot检测VEGF蛋白表达。结果感染Ad-HGF的BMSCs移植2、7 d时在大鼠体内表达HGF蛋白。心功能及血流动力学检测显示,G-CSF组左室收缩压(left ventricular systolic pressure,LVSP)、左室舒张末期压力(left ventricularend-diastolic pressure,LVEDP)、LVSP上升/降低时间(dP/dtmax)、FS与对照组相比差异均无统计学意义(P>0.05);HGF组和联合治疗组与对照组相比,LVEDP显著降低,LVSP、FS和dP/dtmax显著升高(P<0.05);与HGF组相比,联合治疗组的FS和dP/dtmax升高(P<0.05)。免疫荧光双染显示心肌梗死交界区增生细胞是血管内皮细胞。联合治疗组血管密度明显高于其他3组(P<0.05),VEGF蛋白表达较其他3组明显增加(P<0.05)。结论 在大鼠心肌梗死4周时给予G-CSF联合携带HGF基因的BMSCs移植治疗,可明显改善心功能,促进心肌梗死边缘缺血区域的血管生成,其作用机制之一是增加了缺血心肌VEGF蛋白的表达。     

骨髓间充质干细胞移植对大鼠慢性癫痫模型腺苷系统的重建作用

目的 探讨骨髓间充质干细胞(MSC)移植对大鼠慢性癫痫模型腺苷系统的重建作用.方法 Wistar大鼠腹腔注射氯化锂及硝酸毛果芸香碱制作癫痫模型.将取自正常Wistar大鼠的MSC在培养后移植入癫痫模型大鼠的海马CA3区(MSC组).以腹腔注射生理盐水及海马区注射磷酸盐缓冲液的正常Wistar大鼠为对照(对照组).移植前和移植后3个月时进行大鼠脑电图检测,移植后3个月检测大鼠脑内腺苷A1及A2a受体的表达情况.结果 移植后3个月时,MSC组大鼠腺苷A1受体表达水平高于对照组.A2a受体表达水平低于对照组.MSC组A1受体升高在颞叶及海马尤为明显,A2a受体降低在丘脑尤为明显.MSC组中,移植前(慢性癫痫大鼠模型)的棘波频率为(19.65±2.18)次/页,波幅为(297.43±25.37)mV,移植后大鼠棘波发放的频率明显减少,为(7.48±0.91)次/页,且波幅明显降低,为(86.27±7.72)mV.结论 骨髓间充质干细胞移植可改善大鼠脑内腺苷受体的表达,重建功能异常的腺苷系统,并使大鼠脑内海马和顶叶皮层的痫样放电得到显著改善.     

一种从骨髓血凝块中分离间充质干细胞的方法

目的 探讨一种从骨髓血凝块中分离培养间充质干细胞的简易方法.方法 采集肝素化骨髓标本7份,部分加入凝血酶以模拟血液凝固过程,并于0、8和16 h分别使用尿激酶或机械处理,分为尿激酶处理组、机械处理组、凝固未处理组及未凝固对照组.各组标本经氯化铵溶解红细胞后,分别进行成纤维细胞集落形成单位(CFU-F)和MSC传代培养.计每组CFU-F及第0、1和2代MSC数量.流式细胞仪测定细胞表型,组织化学法检测细胞体外成骨和成脂肪能力.结果 尿激酶处理组样本CFU-F数平均为(33.71±23.54),接近于未凝固对照组样本(40.43±21.29)(n=7,P＞0.05),显著高于机械法处理组(13±11.91)(n=7,P＜0.01)和凝固未处理组(3.71±3.89)(n=7,P＜0.01).储存8或16h后的标本,各组CFU-F形成能力下降,而未凝固对照组和尿激酶处理组数量仍显著高于另外两组(P＜0.05).标本储存不同时间进行MSC传代培养,未凝固对照组及尿激酶处理组细胞数量无明显差别,但均显著高于凝固未处理组及机械处理组.各组MSC均表达CD73和CD90,不表达CD31和CD45.经特异诱导后,各组MSC均呈现碱性磷酸酶活性,细胞内出现亲油红O染料的脂肪滴.结论 对于已经凝固的骨髓标本而言,尿激酶预处理是分离培养MSC的良好途径.     

咪达唑仑和异丙酚对急性心肌梗死大鼠血清VEGF浓度及G-CSF药物动员骨髓干细胞效果的影响

目的 评价咪达唑仑和异丙酚对急性心肌梗死大鼠血清血管内皮生长因子(VEGF)浓度及粒细胞集落刺激因子(G-CSF)药物动员骨髓干细胞效果的影响.方法 雄性Wistar大鼠36只,体重250 ～ 280 g,采用结扎左冠状动脉前降支的方法制备急性心肌梗死模型,采用腹腔连续注射G-CSF 5d进行药物动员,于药物动员后第7天,按照随机数字表法,将大鼠随机分为G-CSF组(G组)、咪达唑仑组(M组)及异丙酚组(P组),每组12只.G组以0.5 ml/h的速率股静脉输注生理盐水6h;M组股静脉输注咪达唑仑0.05 mg·kg-·h-1 6 h;P组股静脉输注异丙酚5mg·kg-1 ·h-16 h.于给药完毕后经股静脉取血,采用流式细胞仅测定CD34+单核细胞( CD34+ MNC)和内皮祖细胞(EPCs)数目,采用ELISA法测定血清VEGF浓度.于心肌梗死后4周每组随机取6只大鼠测定左心室舒张末压(LVEDP)、最大收缩速率(+dp/dtmax)和最大舒张速率(- dp/max).结果 与G组比较,M组CD34+MNC及EPCs细胞数目增加,血清VEGF浓度升高,LVEDP下降,-dp/dtmax的绝对值升高(P＜0.05),P组LVEDP下降,- dp/dtmax的绝对值升高(P＜0.05);与P组比较,M组CD34+MNC及EPCs细胞数目增加,血清VEGF浓度升高,LVEDP下降,- dp/dtmax的绝对值升高(P＜0.05).结论 咪达唑仑可促进VEGF的释放,加强G-CSF动员骨髓干细胞的作用,改善急性心肌梗死后大鼠的心脏功能;异丙酚不能促进VEGF的释放及无骨髓干细胞动员的作用.     

吡那地尔诱导失血性休克大鼠血流动力学保护

目的 观察吡那地尔诱导失血性休克大鼠血流动力学的保护及与线粒体ATP激活钾通道( KATP)的关系.方法 采用失血性休克复苏大鼠,观察吡那地尔预处理对大鼠存活时间、血流动力学指标[平均动脉压(MAP)、左室收缩压(LVSP)、左室舒张末压(LVEDP)、左室压最大上升/下降速率(±dp/dtmax)、心率(HR)]的影响,以及线粒体KATP关闭剂5-羟基癸酸(5-HD)和格列本脲对其效应的作用.结果 吡那地尔预处理显著延长大鼠存活时间,恢复血流动力学,MAP、LVSP、LVEDP、+dp/dtmax、- dp/dtmax、HR分别增高5.9％、11.6％、32.9％、28.0％、28.1％和13.4％(P＜0.01),5-HD和格列本脲可显著抑制其保护效应(P＜0.01).结论 吡那地尔开放线粒体KATP,保护失血性休克大鼠血流动力学,提高存活率.     

烧伤大鼠血清对不同来源间质干细胞的趋化作用

目的了解间质干细胞(MSC)的来源,观察烧伤大鼠血清对不同来源 MSC 的趋化作用。方法将72只大鼠采用完全随机法分成烧伤组(36只,制作背部30%TBSAⅢ度烧伤模型)、假伤组(36只,37℃模拟致伤)。从两组大鼠骨髓、外周血中分离并培养 MSC,在倒置显微镜下观察各组 MSC 的阳性率,比较其生长速度和细胞形态。同时观察不同血清对 MSC 的趋化作用及不同来源 MSC 的迁移能力。结果两组大鼠的骨髓内均培养出贴壁生长的 MSC。烧伤组12只大鼠外周血中有7只培养出 MSC,其阳性率(58%)明显低于骨髓培养(100%,P<0.05)。假伤组大鼠的外周血内未见 MSC(P<0.05)。倒置显微镜下可见原代接种后24h 有少量贴壁细胞,2～3d 后见其生长,散在贴壁,大多呈梭形。各组 MSC 形态无明显差异,均呈纺锤形生长。烧伤大鼠血清处理的假伤组骨髓 MSC 的迁移数[(94±11)个/高倍视野]明显多于正常大鼠血清和胎牛血清处理者[(37±6)、(38±11)个/高倍视野,P<0.01],后两者处理的 MSC 迁移数相近(P>0.05)。假伤组大鼠骨髓MSC 被不同血清趋化时迁移的细胞数明显少于烧伤组大鼠骨髓和外周血 MSC(P<0.05或0.01)。烧伤组大鼠骨髓 MSC 与外周血 MSC 的迁移能力虽有差异,但无统计学意义(P>0.05)。结论烧伤大鼠骨髓及外周血均能分离到 MSC,而正常大鼠仅骨髓能分离到 MSC。烧伤大鼠血清对 MSC 有较强的趋化作用。烧伤大鼠来源的 MSC 比正常大鼠来源的 MSC 具有更强的迁移能力。     

脐血间充质干细胞移植对大鼠局灶性脑缺血的影响

目的　从人脐血中分离纯化间充质干细胞(MSC) ,观察其移植对大鼠大脑中动脉栓塞后神经功能恢复的影响及细胞的存活、迁移向神经细胞分化的情况。方法　雄性SD大鼠45只,用线栓法建立大鼠大脑中动脉栓塞(MCAO)模型,大鼠随机分为3组:MSC移植组、单核细胞组和生理盐水组。移植后1、7、14、2 1、2 8d采用改良神经功能损害评分(mNSS)观察大鼠神经功能恢复情况,应用免疫组织化学和免疫荧光双标记技术检测5溴 2脱氧尿核苷(BrdU )标记的MSC细胞的存活、迁移及其胶质纤维酸性蛋白(GFAP)和神经元特异性核蛋白(NeuN)的表达。结果　人脐血MSC细胞移植可显著提高大鼠局灶性脑缺血后神经功能的恢复(P <0 .0 5 )。移植的MSC细胞可在大鼠脑组织中存活,并向缺血区域迁移,11.67%MSC细胞表达GFAP ,3 .72 %MSC细胞表达NeuN。结论　人脐血中含有MSC细胞并可促进局灶性脑缺血大鼠的神经功能恢复,移植细胞可在大鼠脑缺血区域中存活、迁移并向星形胶质细胞或神经元分化     

糖尿病大鼠离体心脏对缺血/再灌注的耐受性

目的评价糖尿病大鼠离体心脏缺血／再灌注后心脏功能的改变。方法链佐星(60mg／kg)诱导的糖尿病大鼠16只(D组),年龄匹配的健康雄性SD大鼠10只(C组),戊巴比妥钠(60mg／kg)麻醉后快速取出心脏,接上主动脉插管置于Langendorg装置上,Krebs-Henseleit缓冲液逆行灌注。平衡灌注20min,待心率(HR)及冠脉流量平稳后夹闭灌注道,进行全心缺血30min,复灌40min。持续监测心肌心电活动、左心室压峰值(LVPSP)、左室舒张末压(LVEDP)和左室压力最大上升／下降速率(±dp／dtmax),计算左室发展压(LVDP=LVPSP-LVEDP),用LVDP×HR(RDPP)表示左室作功。结果与C组相比,基础状态下,D组大鼠心脏HR减慢,LVDP、RDPP和±dp／dtmax降低,LVEDP升高(P<0.05或0.01);再灌注后HR、LVDP、RDPP、冠脉流出液、±dp／dtmax等心功能指标恢复百分率升高,肌酸激酶活性降低(P<0.05或0.01);心脏缺血-停搏时间延长。结论糖尿病心脏基础心功能损伤严重,但对缺血／再灌注的耐受性增强。     

表达IκBα突变体的树突状细胞对大鼠移植肾存活时间的影响

目的 观察IκBα突变体基因修饰的供体树突状细胞(IκBαM-Dc)对大鼠移植肾存活时间的影响.方法 利用重组腺病毒载体将IκBαM基因转染WF大鼠骨髓DC,流式细胞仪检测DC共刺激分子CD80、CD86表达.以wF大鼠为供体,Lewis大鼠为受体,行同种肾移植.术前7 d,受体输注供体IκBαM-DC作为IκBαM组,未输注IκBαM-DC的受体作为对照组,观察移植肾存活时间和术后肾功能变化.术后第14天检测受体T细胞对供体成熟DC及第三方大鼠成熟DC的反应性.结果 IκBαM明显抑制DC共刺激分子CD80、CD86表达.IκBαM组受体鼠移植肾存活时间为(32.5±7.8)d,较对照组移植肾存活时间(8.5±1.7)d明显延长(P<0.01);而其术后7 d血清肌酐为(57.3±8.2)μmol/L,较对照组血清肌酐(498.0±46.3)μmol/L明显减低.肾移植术后,IκBαM组受体T细胞对供体成熟DC反应明显低于对照组,而对第三方大鼠成熟DC的反应性与对照组比较,差异无统计学意义(P>0.05).结论 表达IκBα突变体的供体树突状细胞能诱导受体大鼠T细胞对供体抗原的免疫低反应,显著延长大鼠移植肾存活时间.     

Heat shock-induced protection of renal proximal tubular epithelial cells from cold storage and rewarming injury

Cold storage and reperfusion injury to transplanted kidneys contributes to increased incidence of delayed graft function and may have a negative impact on graft survival. This study examined the mechanisms by which previous heat shock protects against cell death in an in vitro model of kidney storage. Cold storage is mimicked by incubating human renal proximal tubular epithelial (HK-2) cells in University of Wisconsin solution at 4 degrees C with and without subsequent rewarming. Heat shock was induced by incubation of cells at 42 degrees C for 1 h. Altered protein expression was measured by Western blot, and cell viability and apoptosis were measured by propidium iodide DNA staining using flow cytometry. The specific role of heat-shock protein 70 (HSP-70) was determined both by siRNA knockdown and by stable overexpression approaches. Cold storage and rewarming-induced cell death was associated with decreased expression of HSP-70, HSP-90, HSP-27, and Bcl-2. Previous heat shock significantly reduced HK-2 cell death after cold storage and rewarming and was associated with the maintenance of HSP-70, HSP-27, and Bcl-2 protein levels. Blocking heat stress-induced HSP-70 with siRNA did not significantly block the protective effect of heat stress against cold storage and rewarming cell death; however, overexpression of HSP-70 protected HK-2 cells from this stress. It is concluded that previous heat shock protects HK-2 cells from cold storage and rewarming injury. siRNA inhibition of HSP-70 induction did not block the protective effect of heat shock, indicating that HSP-70 is not essential to the heat stress-induced protective effect reported in this study.     

Mechanical deformation induced apoptosis in human proximal renal tubular epithelial cells is caspase dependent

PURPOSE: Ureteral obstruction (UO) results in apoptosis of renal tubular epithelial cells. We postulated that mechanical deformation and inflammation contribute to the cellular loss that occurs as a result of UO and it is mediated through altered heat shock protein 70 (HSP-70) expression and the caspase cascade. MATERIALS AND METHODS: Human HK-2 renal tubular cells were subjected to mechanical stretch. Cell viability and apoptosis were assessed by flow cytometry; HSP-70 and caspase 3 protein expression by Western blotting, and caspase 3 activity by fluorescence substrates. RESULTS: Mechanical stretch caused direct apoptosis induction and it also primed for tumor necrosis factor-alpha induced apoptosis, which was caspase 3 dependent. Although HSP-70 protein expression was increased during mechanical stretch, the protective effects of HSP-70 were only seen after further induction by heat shocking. CONCLUSIONS: Altering HSP-70 expression and manipulating the caspase cell death proteases represent a novel pathway to protect against renal tubular cell apoptosis and the potential for progression to renal failure in UO.     

Kinetics of plasma heat shock protein HSP-70 release in coronary artery surgery: on-pump versus off-pump

AIM: Heat shock protein HSP-70 is known as protective chaperone molecule synthetized in response following ischemia and stress agents. It is detected in the myocardium and endothelium as well as in the circulation. Damaged as well as viable but exposed to stress cells contribute to the release of HSP-70 into the circulation. The aim of the study was to investigate if cardiopulmonary bypss (CPB) leads to more circulating HSP-70, on the basis of comparison dynamics of plasma concentration HSP-70 in 8 men undergoing procedures with the use of CPB (coronary artery bypass grafting, CABG group) and 8 men undergoing off-pump surgery (OPCAB group). METHODS: Blood samples were taken preoperatively, twice intraoperatively, immediately after surgical procedure (1 h) and 24-hours thereafter. The concentration of plasma HSP-70 was measured by means of immunoassay. The derived results were compared statistically with the frequency of incidence postoperative atrial fibrillation (AF). RESULTS: In CABG group was observed continuous gradual increase of plasma HSP-70 concentration during the operation with the peak 1 h after surgery (P<0.01), in striking contrast to OPCAB group, in which was detected small, but non statistically significant increase of HSP-70 1 h after operation. Significantly more of circulating HSP-70 it was detected in CABG group during the operation and 1 h after surgery (CABG vs OPCAB, respectively P<0.015 and P<0.028). In both groups among patients witch AF it was found higher postoperative values of circulating HSP-70 compared with the non-AF group (P=0.0415). CONCLUSIONS: The use of CPB leads to significant more release of HSP-70 into the circulation. According to our findings high plasma concentration of HSP-70 may be the measure of operative cellular stress, ischemia or injury and may be related with greater onset of postoperative AF. High circulating HSP-70 levels is connected with higher incidence of postoperative AF after open heart surgery.     

Pretransplant induction of HSP-70 in isolated adult pig islets decreases early islet xenograft survival

The heat-induced HSP-70 expression protects rat islet single cells against lysis mediated by nitric oxide (NO), reactive oxygen, and streptozotocin. The present study was performed to investigate the potential antiinflammatory effect of pretransplant heat shock in adult pig islets for subsequent early islet xenograft survival. Maximum HSP-70 expression in freshly isolated pig islets was induced by hyperthermia at 43 degrees C for 90 min prior to islet regeneration at 37 degrees C for 4-6 h. Heat-stressed and sham-treated islets were incubated in 0.6 mM H2O2 or 1.5 mM Na-nitroprusside at 37 degrees C for 20 h. Early graft survival was evaluated in normoglycemic Lewis rats after simultaneous, contralateral transplantation of heat-shocked islets and sham-treated islets into the renal subcapsular space of the same recipient. Prior hyperthermia significantly reduced specific lysis of islets exposed to NO or H2O2, although protection was only marginal. No differences were observed between viability of heat-shocked and sham-treated islets after NO exposure. In contrast, prior heat shock increased islet viability after H2O2 treatment. The finding that hyperthermia reduced recovery of initially grafted pig insulin 48 h after transplantation by 30% compared to controls contrasted significantly with an increased insulin recovery in heat-exposed islets at the end of simultaneous 37 degrees C culture. The observation, that the heat-induced HSP-70 expression decreases early islet xenograft survival as reflected by recovery of grafted insulin, implies an enhancement of islet immunogenicity and the induction of apoptosis. Future experiments aiming at augmentation of intrinsic defense mechanisms should consider detrimental effects associated with induction of heat shock proteins.     

Prevalence of heat shock protein in patients with Meniere''s disease and allergy

OBJECTIVE: The study purpose was to investigate the prevalence of elevated heat shock protein 70 (HSP-70) in patients with Meniere's disease who have milk allergy compared with those who are not allergic to milk. METHODS: Fifty-five patients with Meniere's disease and allergy in whom milk allergy had been confirmed by intradermal progressive dilutional food testing or skin testing to milk antigen were included. Blood serum was tested for HSP-70 elevation with a Western blot assay using bovine renal extract. The 29 women and 26 men ranged in age from 29 to 76 years (mean age 52.8 years). Forty percent of the patients had bilateral Meniere's disease. RESULTS: Overall prevalence of HSP-70 elevation was 29.1%. This was higher in bilateral patients (50%) than unilateral patients (15%) (P 相似文献   

TNFR gene-modified mesenchymal stem cells attenuate inflammation and cardiac dysfunction following MI

OBJECTIVES: To investigate the protective effect of tumor necrosis factor receptor (TNFR) gene modified mesenchymal stem cells (MSCs) transplantation against inflammation and cardiac dysfunction following acute myocardial infarction (AMI). DESIGN: MSCs were extracted from the tibias and femurs of rats and transfected with recombinant adeno-associated viral (rAAV) expressing EGFP (enhanced green fluorescent protein) or p75 (human 75 kilodalton) TNFR at multiplicity of infection of 10(5) particles/cell. Rats with AMI induced by occlusion of the left coronary artery were randomized to MSCs-TNFR transplantation group, MSCs-EGFP transplantation group and MI control group. RESULTS: The effects of MSCs-TNFR transplantation on cardiac inflammation and left ventricular dysfunction were observed after 2 weeks of MI. We found that: 1) MSCs-TNFR transplantation attenuated protein production and gene expression of inflammatory cytokines TNF-, IL-1beta and IL-6; 2) MSCs-TNFR transplantation inhibited cardiomyocytes apoptosis and 3) MSCs-TNFR transplantation improved left ventricular function. CONCLUSIONS: The experimental data show that transplantation with rAAV-TNFR transfected MSCs improves left ventricular function following MI through anti-apoptotic and anti-inflammatory mechanisms.     

Selective and non-selective cox inhibitors up-regulate heat shock protein-70 expression and protect human monocytes and macrophages from the cytotoxic effect of hydrogen peroxide

Heat shock protein 70 (HSP-70) is a molecular chaperone that protects cells against stress stimuli. The expression of HSP-70 is normally up regulated in response to stress. However, in patients with severe sepsis, HSP-70 expression is suppressed. We hypothesized that inhibitors of cyclooxygenase (COX) could up regulate the expression of HSP-70 in human macrophages and monocytes, which in turn will improve the resistance of these cells to stress. Human monocytes and macrophages were untreated or treated with aspirin, ibuprofen or NS-398, a selective COX-2 inhibitor, for 1.5 to 24 hrs. A parallel group was exposed to a 30-min heat shock at 42°C. Western blotting and real-time polymerase chain reaction quantified, respectively, time dependent changes in HSP-70 protein expression and mRNA production. To evaluate whether elevated HSP-70 expression protects the cells from stress, cell viability was determined after exposure of cells to cytotoxic concentrations of hydrogen peroxide. Changes in cell viability were monitored using propidium iodide and fluorescent microscopy. Treatment of the monocytes or macrophage cultures with either aspirin, ibuprofen or NS-398 caused a statistically significant increase (p < 0.05; n = 4) of about 2.5 fold in HSP-70 mRNA expression that peaked at 1.5 hrs. Heat shock caused a 25-fold increase in HSP-70 mRNA expression at 1.5 hrs. The COX inhibitors also triggered a statistically significant increase (p < 0.05; n = 8) of about 2-fold in HSP-70 expression within 1.5 hrs of treatment, while the heat shock triggered a 3-5 fold increase in both cell populations. The protein levels remained elevated for 24 hrs in all treated groups. Significantly, pretreatment of the cells with either the COX inhibitors or the heat shock protected the cells from the cytotoxic effect of hydrogen peroxide. These findings suggest that both selective and non-selective COX inhibitors may be as effective as a febrile response in augmenting the body’s resistance to stress.     

Mesenchymal stem cells participate in angiogenesis and improve heart function in rat model of myocardial ischemia with reperfusion.

OBJECTIVE: The effect of transplanted mesenchymal stem cells (MSCs) on the left ventricular (LV) function and morphology in a rat myocardial infarct heart with reperfusion model were analyzed. METHODS: One week after 60 min of myocardial ischemia and reperfusion by left anterior descending artery (LAD) occlusion, 1.0x10(7) 6-diamidino-2-phenylindole (DAPI)-labeled MSCs were injected into the infarcted myocardium and compared with controls, and sham-operated rats, in which a cell-free serum medium was injected into the infarcted region or the myocardial wall, respectively. Measurement of vascular endothelial growth factor (VEGF) expression 1 week after MSC injection using Western blot analysis (n=5), and immunohistochemical staining using HE staining and fluorescent microscopy of the DAPI-positive regions from MSC implantation, cTnT immunostaining of potential myocardial-like cells, and SM-actin and CD31 immunostaining demonstrating neovascular transformation of implanted MSCs 1 week, 2 weeks and 4 weeks after transplantation (n=5). Hemodynamic measurements were performed after 4 weeks in vivo. Subsequently, hearts were quickly removed and cut for histological analysis using HE staining with measurement of the infarcted LV-area, the LV-wall thickness within the scar segment compared to non-infarcted scar segments, and the capillary density counting capillary vessels with 400x light microscopy (n=10). RESULTS: Measurement of hemodynamics 4 weeks after transplantation in vivo showed LV function to be significantly greater in MSCs than in the control group. Semi-quantitative histomorphometric examinations showed a significantly lower infract size, a greater LV-wall thickness, and a lower Hochman-Choo expansion index in the MSC-treated group compared to the control group. Immunofluorescence demonstrated that transplanted MSCs were positive for cTnT, suggesting that a small number of transplanted MSCs can differentiate into cardiomyocytes. Other MSCs were positive for CD31 and SM-actin. The transplanted MSCs in MI area had significantly higher expression rates of cTnT, CD31 and SM-actin 2 weeks after transplantation. HE staining showed marked augmentation of neovascularization in the MSC group. Semi-quantitative analysis demonstrated that capillary density was significantly higher in the MSC group than in the control group. CONCLUSION: Implanted MSCs could improve cardiac structure and function through the combined effect of myogenesis and angiogenesis.     

Acute allograft rejection occurs independently of inducible heat shock protein-70

Dendritic cells (DCs) are key mediators of the innate response to transplantation. Yet, the substances that activate these cells during acute allograft rejection remain elusive. Previous work has suggested that heat shock protein (HSP)-70 is associated with acute allograft rejection. Hence, the goal of this study was to determine whether HSP-70 activates DCs and plays a critical role in acute allograft rejection in an experimental model that is dependent on innate MyD88 signaling. Our in vitro data indicate that HSP-70 does not activate DCs. In vivo transplant studies demonstrate that HSP-70 levels are not increased during acute allograft rejection and that an absence of the inducible form of HSP-70 neither delays acute allograft rejection, impairs DCs maturation, nor alters Th1 immune responses during acute allograft rejection. In conclusion, our results indicate that HSP-70 in our experimental models does not play an essential role in acute allograft rejection.     

Ozone oxidative preconditioning is mediated by A1 adenosine receptors in a rat model of liver ischemia/ reperfusion.

The liver is damaged by sustained ischemia in liver transplantation, and the reperfusion after ischemia results in further functional impairment. Ozone oxidative preconditioning (OzoneOP) protected the liver against ischemia/reperfusion (I/R) injury. The aim of this study was to investigate the role of A(1) adenosine receptor on the protective actions conferred by OzoneOP in hepatic I/R. By using a specific agonist and antagonist of the A(1) subtype receptor (2-chloro N6 cyclopentyladenosine, CCPA and 8-cyclopentyl-1,3-dipropylxanthine, DPCPX respectively), we studied the role of A(1) receptor in the protective effects of OzoneOP on the liver damage, nitiric oxide (NO) generation, adenosine deaminase activity and preservation of the cellular redox balance. Immunohistochemical analysis of nuclear factor-kappa B (NF-kappaB), tumor necrosis factor alpha (TNF-alpha) and heat shock protein-70 (HSP-70) was performed. OzoneOP prevented and/or ameliorated ischemic damage. CCPA showed a similar effect to OzoneOP + I/R group. A(1)AR antagonist DPCPX blocked the protective effect of OzoneOP. OzoneOP largely reduced the intensity of the p65 expression, diminished TNF-alpha production, and promoted a reduction in HSP-70 immunoreactivity. In summary, OzoneOP exerted protective effects against liver I/R injury through activation of A(1) adenosine receptors (A(1)AR). Adenosine and (.)NO produced by OzoneOP may play a role in the pathways of cellular signalling which promote preservation of the cellular redox balance, mitochondrial function, glutathione pools as well as the regulation of NF-kappaB and HSP-70.