ERK介导的炎性反应参与肾缺血再灌注损伤

目的研究小鼠肾缺血再灌注损伤的发病机制。方法建立小鼠肾缺血再灌注损伤模型。12只雄性C57BL／6随机分为2个组（n=6）,分别为假手术组（Sham）,肾缺血再灌注损伤模型组（IRI）。IRI组血管夹夹闭左肾动脉,置于32℃温箱后1h松开血管夹,去除右肾。Sham组操作同上,但不夹闭左肾动脉。再灌注24h后处死小鼠,收集血清和肾脏标本。测定血清肌酐（Cr）和血尿素氮（BUN）。PAS染色后显微镜下观察肾脏形态学变化,Western印迹分析ERK、p-ERK的表达,PCR检测MCP-1、IFN-γ。结果与假手术组（Sham）相比,IRI组血清肌酐、血尿素氮明显升高,病理检查可见肾脏内肾小管上皮细胞明显肿胀坏死、蛋白管型形成明显,还可观察到炎性细胞浸润明显增加。ERK、p-ERKWestern印迹结果PCR显示MCP-1、TNF-α也明显上调,但ERK表达不变。结论在肾缺血再灌注中,ERK激活介导的炎性后府可能参与了肾扣伤。     

Toll样受体2和4在大鼠心肌缺血/再灌注损伤模型中的动态表达

目的:通过观察大鼠心肌组织缺血/再灌注(I/R)急性期Toll样受体2(TLR2)和4(TLR4)mRNA及蛋白质的表达,探讨TLR2和TLR4在心肌缺血/再灌注损伤中的作用。方法:雄性Wistar大鼠随机分为缺血/再灌注组(I/R组)和假手术组(sham组),建立大鼠心肌缺血/再灌注模型,按不同的再灌注时间(1、2、4、6、12、24 h和7 d)处死动物(n=42)。光镜下观察心肌组织形态改变。实时定量聚合酶链式反应(RT-PCR)定量心肌TLR2及TLR4mRNA水平。逆转录聚合酶链式反应(r-t PCR)测定心肌白介素-6(IL-6)和单核细胞趋化因子-1(MCP-1)的mRNA水平。结果:①随着再灌注时间的延长,心肌梗死面积逐渐增大,在再灌注4 h时达最大值,再灌注4 h、6 h、12 h、24 h,再灌注7 d已发生心室重塑。②在再灌注早期,sham组心肌组织形态未见明显改变,I/R组心肌结构有不同程度损伤,在复灌7 d时可见心室重塑,左室壁厚度明显变薄,大量成纤维细胞替代原有的心肌细胞。③sham组和I/R组TLR2、TLR4、MCP-1和IL-6mRNA水平均出现不同程度上调,其中TLR2和TLR4均在再灌注4 h时达高峰,随后逐渐下降,至再灌注7 d时TLR4水平再次升高。IL-6在6 h达到高峰后开始下降,到24 h时基本降至sham组水平,再灌注7 d时再次有升高趋势。MCP-1在缺血/再灌注后一直保持与sham组相当水平,在再灌注7 d时才有明显升高。结论:在心肌缺血/再灌注早期,心肌组织中TLR2和TLR4基因水平迅速上调,并促进下游炎症因子的产生造成心肌早期的损伤。在再灌注后期,TLR2和TLR4的再次升高使得炎症因子的表达再一次增加,从而影响心肌重塑,损伤心肌结构及功能。     

Eritoran对大鼠肾脏缺血再灌注损伤的保护作用

目的:观察eritoran对大鼠肾脏缺血再灌注损伤模型的.方法:建立SD大鼠缺血再灌注模型,给予eritoran治疗而对照组给予生理盐水治疗,观察各组的肾功能情况、肾组织光镜病理,并采用核糖核酸酶保护测定检测肾组织炎症因子/趋化因子的表达.结果:与模型组相比,eritoran预处理可显著改善大鼠的肾功能,减轻缺血再灌注引起的肾小管损伤,减轻肾组织病变,减少肾组织单核细胞浸润并下调多种炎症因子的表达(TNF-α,IL-6,IL-1β和MCP-1).结论:本研究证实通过eritoran抑制Toll样受体4,可减轻大鼠肾脏缺血再灌注损伤中的炎症反应,减轻肾脏缺血再灌注损伤,eritoran可望成为肾脏I/R损伤的新治疗手段.     

脑缺血和缺血再灌注大鼠皮层神经元自噬的动态变化

目的：探讨脑缺血和缺血/再灌注不同时间大鼠大脑皮层神经元自噬的变化。方法：健康雄性SD大鼠60只,随机分为：假手术（Sham）组（n=10）,脑缺血和缺血/再灌注模型组（n=50）.模型组分别在缺血30min、2h,缺血2h再灌注1h、6h、24h五个时间点,随机抽取10只大鼠,测定脑梗死体积和脑含水量,同时采用Western印迹法测定各组大鼠大脑皮层中微管相关蛋白轻链3-Ⅱ（LC3-Ⅱ）的水平,透射电镜检测大脑皮层神经细胞自噬情况。结果：脑缺血30min时LC3-Ⅱ/Ⅰ比值未见明显上升,缺血2h时LC3-Ⅱ/Ⅰ比值开始升高,明显高于Sham组（P<0.01）;缺血/再灌注1h、6h时LC3-Ⅱ/Ⅰ比值虽较缺血2h组有所下降,但仍明显高于Sham组（P<0.05）;缺血/再灌注24h时LC3Ⅱ/Ⅰ比值达高峰,明显高于Sham组（P<0.01）。透射电镜观察进一步证实该现象。缺血/再灌注6h和24h时大鼠脑梗死体积明显增加,与Sham组比较有统计学差异（P<0.01）。缺血/再灌注24h大鼠脑组织含水量明显增加,明显高于Sham组（P<0.05）。HE染色显示：仅在缺血/再灌注24h组大鼠皮层见组织水肿、疏松,部分细胞变性、凋亡,海马区见大量神经元细胞核皱缩、深染呈变性凋亡状。结论：局灶性脑缺血和缺血/再灌注模型中大脑皮层缺血2 h神经元自噬即明显激活,缺血/再灌注1 h、6 h自噬均持续增高,缺血/再灌注24 h自噬达高峰。     

刺五加注射液预处理对大鼠肾缺血再灌注损伤的影响

该研究探讨了刺五加(Acanthopanax senticosus,AS)注射液预处理对大鼠肾缺血再灌注损伤(ischemic reperfusion injury,IRI)的保护作用及其可能机制。采取单动脉夹闭法建立大鼠肾缺血再灌注损伤模型。检测各组大鼠血清肌酐(Scr)、尿素氮(blood urea nitrogen,BUN)、丙二醛(malondialdehyde,MDA)、血液中白介素-6(interleukin-6,IL-6)、尿液肾损伤分子-1(kidney injury molecule-1,KIM-1)、6-乙酰-B-D-氨基葡萄糖苷酶(6-acetyl-B-D-glucosaminidase,NAG)的含量。苏木精–伊红染色(hematoxylin-eosin staining,HE)光镜下观察各组大鼠肾组织的病理变化。免疫组化法测定各组大鼠肾组织中细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM-1)蛋白质水平。结果表明,HE染色光镜下观察,IRI组及AS组肾组织出现病理改变,对照组无明显病理变化,而AS组大鼠肾组织损伤较IRI组减轻。AS预处理大鼠肾IRI,可明显降低血清Scr、BUN、MDA、IL-6、尿液KIM-1、NAG量及肾组织中ICAM-1蛋白的表达。认为AS预处理对大鼠急性肾IRI具有明显保护作用,可能与其可以减轻大鼠IRI的炎性损伤反应有关。     

缺血再灌注对大鼠肾脏足细胞podocin的表达影响及意义

目的:观察SD大鼠缺血再灌注肾损伤足细胞表面相关蛋白(podocin)表达的变化,探讨podocin分子在足细胞损伤中的作用.方法:60只雄性SD大鼠随机分为假手术组(S组)30只和模型组(M组)30只,各组又分为lh、3h、6h、12h、24h、48h六个亚组,每个亚组各5只.采用Westemblot蛋白印迹法检测肾皮质足细胞podocin蛋白表达.并观察各组血肌酐、尿素氮的变化.结果:与S组相比,肾缺血再灌注损伤后,M组尿素氮于6h开始升高,且48h达高峰(P＜0.05);血肌酐48 h才升高(P＜0.05).Podocin 蛋白在3h表达开始下降,以后随缺血再灌注时间的延长podocin蛋白的表达逐渐下降,且48h组下降最明显(P＜0.01).结论:(1)缺血再灌注肾损伤时大鼠肾功明显发生改变,尿素氮早期开始升高,血肌酐晚期升高明显,说明造模成功.(2)大鼠肾脏足细胞podocin的蛋白表达随着缺血再灌注时间的延长而改变,早期下降不明显,3h组开始逐渐下降,48h组下降最明显.此结果表明podocin蛋白在肾脏缺血再灌注肾损伤表达减少.我们可以推想在缺血再灌注肾损伤时,podocin随缺血时间延长而表达逐渐减少的同时,也破坏了与足细胞相关蛋白之间的联系,这种关系的破坏最终导致足细胞受损.通过对足细胞表面蛋白podocin的研究,对将来肾脏足细胞损伤的防治提供新的思路.     

肌肽对大鼠缺血-再灌注损伤后热休克蛋白70及炎性因子表达水平的影响

目的通过失血性休克大鼠血液回输后造成的缺血-再灌注损伤（IRI）模型,研究肌肽对IRI后丙二醛（malondialdehyde,MDA）浓度、热休克蛋白70（HSP70）及炎性因子表达水平的影响。方法27只Wistar大鼠随机分成3组制作IRI模型,大鼠失血至40mmHg→雌持20min→放置1h→全血回输→维持3h→处死。大鼠处死后取血浆检测MDA浓度,取肝、脑、肺、心、肾、脾组织制作石蜡切片,通过免疫组化染色比较肝、脑、肺、心、肾、脾组织切片HSP70阳性细胞数;取肝组织提取RNA比较肝组织HSP70及炎性因子mRNA表达量。结果与再灌损伤组相比,肌肽治疗组肝、脑、肺、心、肾、脾组织切片HSP70阳性细胞数及HSPa5、HSPala mRNA表达量明显升高;MDA浓度及IL-6、TNF-α、NF-κB1、SCYA2、SCYA3 mRNA表达量明显降低。结论肌肽可以抑制IRI后MDA的生成、从mRNA水平促进HSP70的表达、抑制炎性因子mRNA的表达。     

肾缺血再灌注损伤大鼠肾内AQP2表达水平降低

目的了解肾脏缺血再灌注损伤(ischemia reperfusion injury, IRI)时肾内水通道蛋白-2(aquaporin 2, AQP2)免疫组织化学表达特点。方法建立大鼠右侧肾IRI 45min模型,随机分为缺血再灌注1d、3d、5d、7d组和假手术1d组,检测尿常规、尿比重、尿素氮、血肌酐;HE染色观察肾脏病理形态学变化;免疫组织化学染色观察IRI时肾脏AQP2表达的变化。结果 IRI后,大鼠出现尿量增多,尿比重降低,血肌酐、尿素氮均增加;HE染色示右侧肾充血,水肿以及肾小管上皮细胞肿胀、坏死和脱落;免疫组织化学染色显示AQP2免疫反应性在右肾降低,左肾增强。肾组织的变化在第7d基本恢复正常。结论肾IRI时肾内AQP2表达降低,可能与IRI后尿量增多、尿比重降低相关。     

CD4^＋T细胞在大鼠心肌缺血再灌注损伤中的作用

目的通过大鼠心肌缺血再灌注损伤的动物模型,分析CD4^＋T细胞在心肌组织损伤中的作用。方法结扎大鼠冠状动脉左前降支45min,随后恢复再灌的方法,制作缺血再灌损伤的动物模型,随机分为再灌注0、2、6、9、12h组及相应的对照组。II导联心电图及TTC确定模型,组织病理学观察心肌细胞的损伤情况,免疫荧光染色计数浸润的炎性细胞,半定量PCR进一步验证各型T细胞的表达。结果心肌的梗死面积与心肌缺血再灌时间成正相关,至观察结束未出现峰值;组织中浸润的中型粒细胞和T细胞分别在2h和12h有峰值出现,但CD4^＋T/CD3^＋T的比率几乎保持不变;观察所见CD4^＋T细胞是组织中存在最多的T细胞。结论大鼠缺血再灌注损伤中,心肌组织中浸润的CD4^＋T细胞作为主要的效应细胞,参与了持续稳定的心肌损伤过程。     

缺血缺氧再灌注对胎鼠肾组织环氧化酶表达的影响

目的观察宫内缺血缺氧再灌注后,胎鼠肾组织COX蛋白表达及其AA代谢产物PGI2、PGE2和TXA2含量的变化,探讨COX在宫内窘迫胎鼠肾损伤发病机制中的作用.方法制备胎鼠子宫内缺血缺氧再灌注模型(缺血缺氧组：缺血缺氧30min;再灌注组：缺血缺氧30min后,分别再灌注30min,2h,6h,12h,24h,30h)缺血氧组：取胎鼠18只;再灌注组各时间点分别取胎鼠18只;对照组取胎鼠20只.将肾组织匀浆后采用Western免疫印迹和放免法检测COX蛋白表达及其PGI2、PGE2和TXA2含量的变化.同时HE染色观察肾组织病理学改变.结果子宫内缺血缺氧再灌注后胎肾组织COX-2蛋白表达上调,PGI2的稳定代谢产物6-Keta-PGF1α及PGE2均于再灌注2h开始增高(P<0.05).其中6-keta-PGF1α增加迅速,于再灌注12h达假手术组的6倍(P<0.01),PGE2于再灌注24h达假手术组的2倍(P<0.01),而TXB2增加幅度不大,无统计学意义.结论宫内缺血缺氧再灌注选择性地诱导胎肾COX-2蛋白表达增强,COX-2可能通过PGI2和PGE2对缺血性胎肾损伤具有保护作用,因此,在围产期肾损伤不宜应用COX-2抑制剂.     

The outcome of renal ischemia-reperfusion injury is unchanged in AMPK-β1 deficient mice

Aim

Activation of the master energy-regulator AMP-activated protein kinase (AMPK) in the heart reduces the severity of ischemia-reperfusion injury (IRI) but the role of AMPK in renal IRI is not known. The aim of this study was to determine whether activation of AMPK by acute renal ischemia influences the severity of renal IRI.

Methods

AMPK expression and activation and the severity of renal IRI was studied in mice lacking the AMPK β1 subunit and compared to wild type (WT) mice.

Results

Basal expression of activated AMPK, phosphorylayed at αThr¹⁷², was markedly reduced by 96% in AMPK-β1^−/− mice. Acute renal ischaemia caused a 3.2-fold increase in α1-AMPK activity and a 2.5-fold increase in α2-AMPK activity (P<0.001) that was associated with an increase in AMPK phosphorylation of the AMPK-α subunit at Thr¹⁷² and Ser⁴⁸⁵, and increased inhibitory phosphorylation of the AMPK substrate acetyl-CoA carboxylase. After acute renal ischemia AMPK activity was reduced by 66% in AMPK-β1^−/− mice compared with WT. There was no difference, however, in the severity of renal IRI at 24-hours between AMPK-β1^−/− and WT mice, as measured by serum urea and creatinine and histological injury score. In the heart, macrophage migration inhibitory factor (MIF) released during IRI contributes to AMPK activation and protects from injury. In the kidney, however, no difference in AMPK activation by acute ischemia was observed between MIF^−/− and WT mice. Compared with the heart, expression of the MIF receptor CD74 was found to be reduced in the kidney.

Conclusion

The failure of AMPK activation to influence the outcome of IRI in the kidney contrasts with what is reported in the heart. This difference might be due to a lack of effect of MIF on AMPK activation and lower CD74 expression in the kidney.     

Early release of macrophage migration inhibitory factor after liver ischemia and reperfusion injury in rats

Macrophage migration inhibitory factor (MIF) is an important mediator of ischemia/reperfusion (I/R) injury in heart, brain and intestine. We previously demonstrated that MIF was released during warm/cold ischemia in vitro. However, the role of MIF in liver I/R injury remains unclear. We aimed to test the hypothesis that MIF acts as an early proinflammatory cytokine and could mediate the inflammatory injury in liver I/R. Rats (n = 6 per group) were subjected to 90 min warm ischemia followed by 0.5 h, 6 h and 24 h reperfusion, respectively to liver transplantation (LTx) after 6 h of cold ischemia followed by 24 h of reperfusion. The expression of MIF, its receptor (cluster of differentiation 74 (CD74)) and the downstream inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β)) were analyzed. Peritoneal macrophages were cultured for 6 h alone or in the presence of effluent from cold-preserved livers or effluent depleted of MIF. Warm I/R increased hepatic MIF-mRNA and protein expression. MIF-protein was released into peripheral circulation in vivo with a maximum at 0.5 h after reperfusion. Induction of MIF-expression was associated with the expression of proinflammatory cytokines and its receptor in both models. MIF released by isolated cold preserved livers, induced TNF-α and IL-1β production by cultured peritoneal macrophages. Intrahepatic upregulation of MIF, release into systemic circulation and the associated upregulation of the proinflammatory mediators suggest a role of MIF in mediating the inflammatory response to I/R injury. Blocking experiments will help to elucidate its role as potential molecular target for preventing hepatic I/R injury.     

Antithrombin III prevents progression of chronic kidney disease following experimental ischaemic‐reperfusion injury

Acute kidney disease (AKI) leads to increased risk of progression to chronic kidney disease (CKD). Antithrombin III (ATIII) is a potent anticoagulant with anti‐inflammatory properties, and we previously reported that insufficiencies of ATIII exacerbated renal ischaemia‐reperfusion injury (IRI) in rats. In this study, we examined the characteristic of AKI‐CKD transition in rats with two distinct AKI models. Based on our observation, left IRI plus right nephrectomy (NX‐IRI) was used to determine whether ATIII had therapeutic effects in preventing CKD progression after AKI. It was observed that NX‐IRI resulted in significant functional and histological damage at 5 weeks after NX‐IRI compared with sham rats, which was mitigated by ATIII administration. Besides, we noticed that ATIII administration significantly reduced NX‐IRI‐induced interstitial fibrosis. Consistently, renal expression of collagen‐1, α‐smooth muscle actin and fibronectin were substantial diminished in ATIII‐administered rats compared with un‐treated NX‐IRI rats. Furthermore, the beneficial effects of ATIII were accompanied with decreased M1‐like macrophage recruitment and down‐regulation of M1‐like macrophage‐dependent pro‐inflammatory cytokines such as tumour necrosis factor α, inducible nitric oxide synthase and interleukin‐1β, indicating that ATIII prevented AKI‐CKD transition via inhibiting inflammation. Overall, ATIII shows potential as a therapeutic strategy for the prevention of CKD progression after AKI.     

The Role of M2 Macrophages in the Progression of Chronic Kidney Disease following Acute Kidney Injury

Introduction

Acute kidney injury (AKI) is a major risk factor in the development of chronic kidney disease (CKD). However, the mechanisms linking AKI to CKD remain unclear. We examined the alteration of macrophage phenotypes during an extended recovery period following ischemia/reperfusion injury (IRI) and determine their roles in the development of fibrosis.

Methods

The left renal pedicle of mice was clamped for 40 min. To deplete monocyte/macrophage, liposome clodronate was injected or CD11b-DTR and CD11c-DTR transgenic mice were used.

Results

Throughout the phase of IRI recovery, M2-phenotype macrophages made up the predominant macrophage subset. On day 28, renal fibrosis was clearly shown with increased type IV collagen and TGF-β. The depletion of macrophages induced by the liposome clodronate injection improved renal fibrosis with a reduction of kidney IL-6, type IV collagen, and TGF-β levels. Additionally, the adoptive transfer of the M2c macrophages partially reversed the beneficial effect of macrophage depletion, whereas the adoptive transfer of the M1 macrophages did not. M2 macrophages isolated from the kidneys during the recovery phase expressed 2.5 fold higher levels of TGF-β than the M1 macrophages. The injection of the diphtheria toxin into CD11b or CD11c-DTR transgenic mice resulted in lesser depletion or no change in M2 macrophages and had little impact on renal fibrosis.

Conclusion

Although M2 macrophages are known to be indispensible for short-term recovery, they are thought to be main culprit in the development of renal fibrosis following IRI.     

Phenotypic and functional characterization of kidney-infiltrating lymphocytes in renal ischemia reperfusion injury

T and B lymphocytes have been implicated in the pathogenesis of renal ischemia reperfusion injury (IRI). The trafficking of lymphocytes into kidneys during IRI has been postulated to underlie this effect, but has not been rigorously studied. We therefore characterized the lymphocyte populations infiltrating into mouse kidneys 3 and 24 h after renal IRI. Immunohistochemistry and flow cytometry staining of kidney lymphocytes showed increased trafficking of CD3+ T cells and CD19+ B cells in both sham-operated and IRI mice 3 h after renal IRI. In the IRI mice, increased infiltration of NK1.1+ and CD4+ NK1.1+ cells compared with normal and sham-operated mice was observed 3 and 24 h after renal IRI, respectively. After 24 h of renal IRI, the decreased percentages of CD3+, CD19+, and NK1.1+ populations in the IRI mice compared with control groups were observed. Increased TNF-alpha and IFN-gamma production of kidney infiltration CD3+ T cells in IRI mice but not sham-operated mice was found. Unexpectedly, isolation and transfer of kidney-infiltrating lymphocytes 24 h after renal IRI into T cell-deficient mice reduced their functional and histological injury after renal IRI, suggesting that kidney-infiltrating lymphocytes could have a protective function. These quantitative, qualitative, and functional changes in kidney lymphocytes provide mechanistic insight into how lymphocytes modulate IRI, as well as demonstrating that abdominal surgery alone leads to lymphocyte changes in kidney.     

大蒜素对全脑缺血再灌注大鼠脑保护机制的研究

目的：通过大蒜素预处理,观察全脑缺血再灌注大鼠海马区ICAM-1 的表达,从而探讨大蒜素的脑保护机制。方法：雄性 Wistar 大鼠30 只,随机分为5 组：假手术组、缺血再灌注组、缺血再灌注+ 大蒜素10、20、30 mg/kg 组。采用四血管闭塞法制备大 鼠全脑缺血再灌注模型,于再灌注24 h 取出海马,硫堇染色观察海马组织的形态学改变,免疫组织化学染色测定海马CA1 区 ICAM-1 免疫反应阳性细胞面积和积分光密度值。结果：通过给予大鼠全脑缺血8 min 再灌注24 h处理,海马CA1 区组织形态学 改变显著,神经元密度明显降低;ICAM-1的表达显著增加。静脉给予大蒜素可使缺血再灌注海马组织形态学改变明显改善,存活 神经元数目增加,ICAM-1 表达显著较少。结论：大蒜素可以通过减少ICAM-1 的表达抑制全脑缺血再灌注后的炎症损失从而发 挥脑保护作用。     

Activation of hypoxia-inducible factor-1 ameliorates postischemic renal injury via inducible nitric oxide synthase

Hypoxia-inducible factor-1 (HIF-1) could ameliorate renal ischemia reperfusion injury (IRI), but the underlying mechanism remains elusive. In the current study, we aim to investigate the possible role of prolyl hydroxylases inhibitor dimethyloxalylglycine (DMOG) in inducing delayed preconditioning-like effects against IRI. Mice were divided into four groups (n = 6): sham group; IRI group; DMOG group: pretreated with DMOG 24 h before IRI; and GW274150 + DMOG group: pretreated with DMOG followed by iNOS inhibitor GW274150 treatment 24 h before IRI. The results showed that the protein level of HIF-1a and the expression of its targets inducible nitric oxide synthase (iNOS), erythropoietin, and heme oxygenase-1 were obviously increased after administration of DMOG. Histological analysis of renal function showed improvement in tubulointerstitial injury due to ischemia by delayed preconditioning with DMOG. GW274150 antagonized the delayed renal protection afforded by DMOG as reflected by deteriorated renal dysfunction, aggravated histological injury, increased renal cell apoptosis, and increased vimentin expression in the kidney. In conclusion, our data demonstrate that DMOG pretreatment induces delayed renal protection against IRI in mice and the beneficial effects are mitigated by pharmacological inhibition of iNOS, suggesting that the protective effects derived from HIF-1 activation via DMOG in the kidney are partially mediated by iNOS.     

Ischemic Preconditioning Increases Endothelial Progenitor Cell Number to Attenuate Partial Nephrectomy-Induced Ischemia/Reperfusion Injury

Objectives

The objective of this study was to investigate the role of endothelial progenitor cells (EPCs) in the modulation of ischemia-reperfusion injury (IRI) in a partial nephrectomy (PN) rat model using early-phase ischemic preconditioning (IPC).

Materials and Methods

Ninety male Sprague-Dawley rats were randomly divided into three groups following right-side nephrectomy: Sham-operated rats (surgery without vascular clamping); PN rats (renal blood vessels were clamped for 40 min and PN was performed); and IPC rats (pretreated with 15 min ischemia and 10 min reperfusion). At 1, 3, 6, 12, 24 h, and 3 days after reperfusion, the pool of circulating EPCs and kidneys were harvested. The extent of renal injury was assessed, along with EPC number, cell proliferation, angiogenesis, and vascular growth factor expression.

Results

Pretreated rats exhibited significant improvements in renal function and morphology. EPC numbers in the kidneys were increased at 12 h following reperfusion in the IPC group as compared to the PN or Sham groups. Cell proliferation (including endothelial and tubular epithelial cells) and angiogenesis in peritubular capillaries were markedly increased in kidneys treated with IPC. In addition, vascular endothelial growth factor-A (VEGF-A) and stromal cell-derived factor-1α (SDF-1α) expression in the kidneys of pretreated rats was increased compared to rats subjected to PN.

Conclusions

Our investigation suggested that: (1) the early phase of IPC may attenuate renal IRI induced by PN; (2) EPCs play an important role in renal protection, involving promotion of cell proliferation and angiogenesis through release of several angiogenic factors.     

姜黄素对自发性高血压大鼠脑缺血/再灌注后海马神经元损伤及RANTES表达的影响

目的：探讨姜黄素对自发性高血压大鼠（SHR）脑缺血/再灌注后认知功能及海马神经元损伤和调解活化正常T细胞表达和分泌的趋化因子（RANTES）表达的影响。方法：雄性Wistar-Kyoto大鼠（WKY）和SHR,随机分为5组：假手术组（W-Sham、S-Sham）、缺血/再灌注组（W-I/R、S-I/R）和姜黄素组（S-Cur）,各组按再灌注时间分为3h、12 h、1 d、3 d、7 d 5个亚组（n=6）。采用四血管阻断法制备全脑缺血/再灌注模型,HE染色观察海马CA1区神经细胞形态,Nissl染色计数海马CA1区平均锥体细胞密度,ELISA法检测海马RANTES表达,于再灌注后7 d观察行为学。结果：与假手术组大鼠比较,缺血/再灌注组大鼠学习和记忆能力下降,海马CA1区神经元损伤加重,海马RANTES蛋白表达上调（P〈0.05）;与W-I/R大鼠比较,S-I/R大鼠学习和记忆能力下降,海马CA1区神经元损伤加重,海马RANTES蛋白表达上调（P〈0.05）;姜黄素组大鼠学习和记忆能力明显改善,海马CA1区神经元损伤减轻,海马RANTES蛋白表达下调（P〈0.05）。结论：缺血/再灌注更易导致SHR海马神经元损伤。姜黄素减轻SHR脑缺血/再灌注海马神经元损伤,其机制可能与抑制RANTES蛋白的表达有关。