热休克蛋白70和血红素加氧酶-1表达在肾缺血后处理减轻肾缺血再灌注损伤中的作用

目的 评价热休克蛋白70(HSP70)和血红素加氧酶-1(HO-1)表达在肾缺血后处理减轻肾缺血再灌注损伤中的作用.方法健康雄性SD大鼠140只,体重250～280 g,采用随机数字表法,将大鼠随机分为4组(n=35):假手术组(S组)仅开腹,游离双侧肾脏,分离双侧肾蒂不夹团;肾缺血再灌注组(I/R组)夹闭双侧肾蒂缺血45 min,恢复灌注;缺血后处理组(IPo组)夹闭双侧肾蒂45 min,再灌注10 s,缺血10 s,反复3次,恢复灌注;HSP抑制剂槲皮黄酮+缺血后处理组(Q+IPo组)缺血前1 h 腹腔注射槲皮黄酮100 mg/kg,余操作同IPo组.于再灌注即刻(T0)、1、3、6、12、24、48 h(T1～6)时各组随机取5只大鼠抽心脏血后取肾,检测肾组织HSP70、HO-1的mRNA和蛋白表达,T3时抽心脏血,测定血清肌酐(Cr)和尿素氮(BUN)浓度、caspase-3 mRNA的表达,TUNNEL法检测肾组织凋亡细胞,计算凋亡指数(AI),光镜下观察肾组织病理学结果.结果 与S组比较,其余组T3时血清Cr和BUN浓度和AJ升高,caspase-3 mRNA表达上调,各时点HSF70、BO-1的mRNA和蛋白表达上调(P＜0.05);与I/R组比较,IPo组T3时血清Cr和BUN浓度和AI降低,caspase-3 mRNA表达下调,T1～5时HSP70、HO-1的mRNA和蛋白表达上调(P＜0.05);与IPo组比较,Q+IPo组T3时血清Cr和BUN浓度和AJ升高,caspase-3mRNA表达上调,T1～5时HSP70、HO-1的mRNA和蛋白表达下调(P＜0.05).IPo组肾组织病理学损伤较I/R组减轻,Q+IPo组肾组织病理学损伤程度与I/R组相似.结论 HSP70和H0-1表达参与了肾缺血后处理减轻肾缺血再灌注损伤的过程.

Abstract：

Objective To evaluate the role of the expression of heat shock protein 70 (HSP70) and heme oxygenase-1 (HO-1) in the reduction of renal ischemia-reperfusion (I/R) injury by ischemic postconditioning in tats.Methods One hundred and forty healthy male SD rats weighing 250-280 g were randomized into 4 groups ( n = 35 each) : sham operation group (S group) ; I/R group; ischemic postconditioning group (IPo group); quercetin (an inhibitor of HSP) + ischemic postconditioning group (Q + IPo group). Renal I/R was produced by clamping bilateral renal pedicels for 45 min followed by reperfusion. In group S, bilateral kidneys were only exposed through a midline incision but their- pedicels were not clamped. In IPo and Q + IPo groups, 45 min ischemia was followed by three 10 s episodes of ischemia at 10 s intervals for reperfusion and in addition intraperitoneal quercetin 100 mg/kg was injected at 1 h before ischemia in group Q + IPo. Blood samples from hearts were obtained at 0, 1, 3, 6, 12, 24 and 48 h of reperfusion (T0-6) and the rats were then sacrificed and kidneys removed to detect the expression of HSP70 and HO-1 mRNA and protein in renal tissues. The blood samples obtained at T3 were used to determine serum creatinine (Cr) and urea nitrogen (BUN) concentrations and the expression of caspase-3 mRNA . The apoptosis in the renal tissues was detected using TUNEL and apoptotic index ( AI) was calculated. Microscopic examination was performed with light microscope. Results Compared with group S, the serum Cr and BUN concentrations and AI were significantly increased at T3,the expression of caspase-3 mRNA was up-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was up-regulated at T0-6 in the other groups (P ＜ 0.05) . Compared with group I/R, the serum Cr and BUN concentrations and AI were significantly decreased at T3, the expression of caspase-3 mRNA was down-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was up-regulated at T1-5 in group IPo ( P ＜ 0.05) . Compared with group IPo, the serum Cr and BUN concentrations and AI were significantly increased at T3, the expression of caspase-3 mRNA was up-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was down-regulated at T1-5, in group Q + IPo ( P ＜ 0.05) . The microscopic examination showed that the renal I/R injury was significantly attenuated by ischemic postconditioning and the degree of injury in group IPo was similar to that in group I/R. Conclusion The expression of HSP70 and HO-1 is involved in the reduction of renal I/R injury by ischemic postconditioning in rats.     

上调肝脏HO-1抑制肥大细胞脱颗粒减轻大鼠肝脏缺血再灌注损伤

目的 探索HO-1对肝脏缺血再灌注损伤中肥大细胞脱颗粒的影响。方法 将20只SD大鼠随机分成4组：假手术组（Sham组）,缺血再灌注损伤组（I/RI组）,HO-1诱导剂钴原卟啉组(CoPP组,术前24h给予CoPP,5 mg/kg)及HO-1抑制剂锌原卟啉组(ZnPP组,术前24h给予ZnPP,20 mg/kg)。建立大鼠缺血再灌注损伤模型,各组于再灌注后2h收集标本。RT-PCR检测肝脏组织HO-1 mRNA表达,Western blot检测肝脏组织HO-1蛋白表达;测定血清中ALT、AST水平;肝脏组织甲苯胺蓝染色检测肥大细胞脱颗粒数量,HE染色评价肝脏组织损伤情况。结果 与Sham组相比,I/RI组、CoPP组、ZnPP组大鼠组织HO-1 RNA和蛋白表达增加,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多,肝脏细胞损伤加重。CoPP组与I/RI组相比,HO-1 mRNA和蛋白表达增加,血清ALT、AST水平减低,肥大细胞脱颗粒数量减少,肝细胞损伤减轻。ZnPP组与I/RI组相比,HO-1 mRNA和蛋白表达减少,血清ALT、AST水平升高,肥大细胞脱颗粒数量增多、肝细胞损伤严重。组间比较差异具有统计学意义(P＜0.05)。结论 HO-1过表达能减轻肝脏I/RI,其机制可能与抑制肝脏组织中肥大细胞脱颗粒有关。     

Expression of Heme Oxygenase-1 in Human Livers Before Transplantation Correlates with Graft Injury and Function After Transplantation

Upregulation of heme oxygenase-1 (HO-1) has been proposed as an adaptive mechanism protecting against ischemia/reperfusion (I/R) injury. We investigated HO-1 expression in 38 human liver transplants and correlated this with I/R injury and graft function. Before transplantation, median HO-1 mRNA levels were 3.4-fold higher (range: 0.7-9.3) in donors than in normal controls. Based on the median value, livers were divided into two groups: low and high HO-1 expression. These groups had similar donor characteristics, donor serum transaminases, cold ischemia time, HSP-70 expression and the distribution of HO-1 promoter polymorphism. After reperfusion, HO-1 expression increased significantly further in the initial low HO-1 expression group, but not in the high HO-1 group. Postoperatively, serum transaminases were significantly lower and the bile salt secretion was higher in the initial low HO-1 group, compared to the high expression group. Immunofluorescence staining identified Kupffer cells as the main localization of HO-1. In conclusion, human livers with initial low HO-1 expression (<3.4 times controls) are able to induce HO-1 further during reperfusion and are associated with less injury and better function than initial high HO-1 expression (>3.4 times controls). These data suggest that an increase in HO-1 during transplantation is more protective than high HO-1 expression before transplantation.     

缺血或药物预处理对大鼠供肝缺血再灌注损伤的抑制作用

目的　探讨缺血预处理 (IPC)或阿霉素预处理 (DPC ,模拟IPC)对大鼠供肝延迟性保护作用的发生机制。方法　将供鼠分为 3组。IPC组 :供鼠采用肝脏预先缺血 10min后再开放 ;DPC组 :供鼠经静脉注射阿霉素 (1mg/kg体重 ) ;对照组 :供鼠用等量生理盐水注射。观察各组预处理后血红素氧化酶 1(HO 1)和热休克蛋白 70 (HSP70 )含量 ;建立上述各组大鼠原位肝移植模型 ,并设假手术对照组 ,观察肝移植后各组对供肝缺血再灌注损伤的影响。结果　IPC组HO 1、HSP70含量分别于预处理 12h和 2 4h达到高峰 ;IPC和DPC组预处理 2 4h ,诱导的HSP70、HO 1含量差异无显著性 (P >0 .0 5 )。对照组肝移植后 6h ,肝组织中ICAM 1mRNA表达和内皮细胞ICAM 1分子表达明显增强 ,髓过氧化物酶 (MPO)活性增高 ,血清中天冬氨酸转氨酶 (AST)、丙氨酸转氨酶 (ALT)、乳酸脱氢酶 (LDH)及肝组织湿重 /干重 (W/D)水平明显升高 ,和假手术组相比 ,差异有显著性 (P <0 .0 1)。IPC或DPC组肝移植后减弱了ICAM 1mRNA和蛋白表达及MPO活性 ,AST、ALT、LDH及W/D的水平亦明显降低 ,与对照组比较 ,差异有显著性 (P <0 .0 5 )。结论　IPC的延迟保护作用是通过降低中性粒细胞的粘附浸润来实现的 ,这与IPC诱导生成HSP70和HO 1有关。DPC可以模拟IPC的延迟性保护     

Alterations in protein tyrosine kinase pathways in rat liver following normothermic ischemia-reperfusion

The phosphoregulation of signal transduction pathways is a complex series of reactions that modulate the cellular response to ischemia-reperfusion (I-R). The aim of this study was to evaluate the effect of normothermic liver I-R on protein tyrosine phosphorylation, production of angiogenic growth factors, and activation of signal proteins in tyrosine kinase pathways. A segmental normothermic ischemia of the liver was induced in rats by occluding the blood vessels (including the bile duct) to the median and left lateral lobes for 120 minutes. Liver extracts from either ischemic or nonischemic lobes were prepared at 0, 1, 3, and 6 hours after reperfusion. Liver tyrosine phosphorylation of proteins was examined by Western blot analysis, whereas vascular endothelial growth factor (VEGF) mRNA was analyzed by Northern blot. In ischemic liver lobes, VEGF mRNA and total protein levels increased at 1 and 3 hours after reperfusion. Tyrosine phosphorylation of the VEGF receptor Flk-1 and the platelet-derived growth factor receptor (PDGF-R) was increased only at 1 hour after reperfusion, while c-Src tyrosine phosphorylation remained increased at 3 hours and remained up to 6 hours after reperfusion. In conclusion, 1-R led to alterations in protein tyrosine phosphorylation and increased expression of VEGF in rat liver.     

Liver HIF-1 alpha induction precedes apoptosis following normothermic ischemia-reperfusion in rats

Apoptosis plays an important role in ischemia-reperfusion (I-R) injury during liver transplantation. The hypoxia-inducible factor alpha (HIF-1alpha) may trigger liver apoptosis following I-R through the induction of hypoxically regulated genes. The aim of this study was to evaluate the effect of normothermic liver I-R on HIF-1alpha expression and apoptosis in rats. Segmental normothermic ischemia of the liver was induced in rats for 120 minutes. Liver extracts from either ischemic or nonischemic lobes were prepared at 0, 1, 3, and 6 hours after reperfusion. Liver HIF-1alpha protein expression was examined by Western blot analysis. Liver apoptosis was quantified using terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end labeling assay. Normothermic I-R resulted in a significant (P< .05) increase in liver HIF-1alpha protein levels 1 and 3 hours after reperfusion. Liver apoptosis was significantly (P< .005) increased at 3 and 6 hours after reperfusion. In conclusion, normothermic liver I-R leads to increased liver expression of HIF-1alpha and apoptosis.     

Effects of N-acetylcysteine in hepatic ischemia-reperfusion injury during hemorrhagic shock

This article seeks to standardize an experimental model of liver ischemia-reperfusion in rats following hemorrhagic shock modulated by N-acetylcysteine (NAC). Twenty-seven adult Wistar rats were randomized into three groups: the HS-IR-Garm underwent hemorrhagic shock with selective hepatic ischemia followed by reperfusion; the HSIR + NAC-G, the same procedure plus NAC; and the control group, only venous catheterization. Blood was withdrawn for 10 minutes until MABP reached 35 mm Hg, which was maintained for 1 hour. The blood was then reinjected as required to maintain MABP at that level. Ringer's lactate solution was infused in a volume equivalent to three times the shed blood, over a period of 15 minutes. Half of the shed blood was reinfused over 5 minutes. HSIR + NAC-G received 150 mg/kg of NAC, during treatment of the shock, and again 10 minutes before reperfusion and continued for 30 minutes. Finally, both groups were subjected to 40 minutes of warm selective hepatic ischemia and reperfusion for 1 hour. Data were analyzed by nonparametric tests (P < or =.05). Liver enzyme levels were higher in HS-IR-G (DHL = 6094 +/- 1688, AST = 746 +/- 175, and ALT = 457 +/- 90) than in HSIR + NAC-G group (DHL = 2920 +/- 284, AST = 419 +/- 113, and ALT = 253 +/- 26). The values in the control group were lower than both experimental groups (DHL = 965 +/- 173, AST = 163 +/- 42, and ALT = 82 +/- 28). Our data showed that liver ischemia-reperfusion injury following hemorrhagic shock produces important hepatic damage and that NAC reduces injury in this rat model.     

Alleviating ischemia-reperfusion injury in aged rat liver by induction of heme oxygenase-1

BACKGROUND: Heme oxygenase-1 (HO-1), a cytoprotective protein, may be important in ameliorating hepatic ischemia-reperfusion (I/R) injury, a critical factor in the dysfunction of the aged liver after transplantation. METHODS: We used hemin to overexpress HO-1 and analyze its effects in a model of I/R in aged livers used for orthotopic transplantation. RESULTS: The SGOT levels in the hemin group were significantly lower than those of the saline treatment group. Hemin liver grafts showed markedly fewer apoptotic (TUNEL+) liver cells after reperfusion compared with the controls. The plasma nitric oxide levels in the hemin group were significantly lower than those in the control group. Unlike untreated or hemin + Znpp-treated orthotopic liver transplant controls, iNOS expression in the hemin group was almost absent at 12 and 24 hours, after reperfusion. In contrast, eNOS was comparable in hemin and saline orthotopic liver transplants. The increased levels of Bcl-2 expression compared with saline controls were most pronounced at 12 hours after transplantation. In contrast, caspase 3 was lower at 24 hours among the hemin-pretreated group compared with saline-treated liver transplant controls. CONCLUSIONS: HO-1 alleviated the I/R injury in the aged liver by suppressing local expression of inducible nitric oxide synthase and by modulating pro- and antiapoptotic pathways.     

Evaluation of warm ischemia-reperfusion injury using heat shock protein in the rat liver

We focused on heat shock protein 70 (HSP70) as a marker of viability in hepatic warm ischemia-reperfusion. Segmental hepatic warm ischemia was produced in rats for 15, 30, 60, 90, 120, or 180 min. Liver sections were evaluated at 30, 60, and 120 min of reperfusion. Expression of HSP70 and messenger RNA (mRNA), apoptosis, and apoptosis-associated genes such as Bcl-2 and Bax were studied. Expression of HSP70 and mRNA was augmented as warm ischemia was prolonged, but was markedly suppressed in livers with more than 120 min of ischemia. The highest accumulation of HSP70 was observed in the nucleus. In livers subjected to longer duration of warm ischemia, necrosis and apoptosis were evident and Bcl-2 mRNA expression and Bcl-2/Bax protein ratio were markedly diminished. Apoptosis may be related to the process of cellular injury induced by warm ischemia-reperfusion. Expression of HSP70 and the Bcl-2 family can be effective markers of viability in hepatic warm ischemia-reperfusion.     

Sequence of reperfusion influences ischemia/reperfusion injury and primary graft function following porcine liver transplantation.

The impact of 3 different reperfusion sequences following orthotopic liver transplantation (OLT) in pigs were evaluated. The reperfusion technique commonly performed is primary portal in order to shorten warm ischemic times (WITs). Experimental and clinical data, usually comparing 2 out of 3 possible reperfusion sequences, provide controversial results. OLT was performed in 24 pigs randomized into 3 groups: primary arterial (A), simultaneous (SIM), and primary portal (P) reperfusion. Hemodynamics were continuously monitored and reperfusion injury and primary graft function were assessed by standard serum parameters, histopathological findings, immunohistochemistry for heme oxygenase 1 (HO-1), and heat shock protein 70 (HSP 70). Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and gamma-glutamyl transpeptidase (gammaGT) following reperfusion were significantly increased for group A when compared to groups SIM and P. Hemodynamics showed significant differences after reperfusion compared to physiological data; differences in group comparisons were not significant. The bile production/100 g liver/hr was significantly higher for group SIM (1.15 mL) compared to group P (0.66 mL) and group A (0.62 mL). Histology and immunohistochemistry significantly correlated with functional results and outcome. Histological score was best for group SIM and worst for group A. HSP 70, being visualized mainly in the hepatocytes, showed higher expression for groups SIM and P. Inversely, HO-1, found in perisinusoidal cells, showed highest expression after primary arterial reperfusion. In conclusion, although associated with a 10-minute longer warm ischemic time, simultaneous reperfusion causes the least reperfusion injury with superior primary transplant function. Primary arterial reperfusion showed the worst overall outcome and highest degree of HO-1 expression.     

Protective effect of ischemic postconditioning on lung ischemia-reperfusion injury in rats and the role of heme oxygenase-1

To investigate the effect of ischemic postconditioning (IPO) on acute lung ischemia-reperfusion (I/R) injury and the protein expression of haeme oxygenase-1 (H0-1), a cytoprotective defense against oxidative injury. Methods: After being anesthetized with chloralhy-drate, forty-eight healthy SD rats were randomly divided into 6 groups (8 in each): sham operation group (S group); I/R group: left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group: left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Hemin (HM)+ I/R group: hemin, an inducer of HO- 1 was injected intraperitoneally at 40 μmol.kg-1·day-1 for two con-secutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX+IPO group: zinc protoporphyrin Ⅸ, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM+S group: HM was administered as in the HM+I/R group without inducing lung I/R. Arterial partial pressure of oxygen (PaO2) and malondialdehyde (MDA) content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-his-tochemical technique and for light microscopic examination. Results: The PaO2 was significantly lower in all the experimental groups compared with sham group (90 mm Hg ±11 mm Hg). However, the values ofPaO2 in IPO (81 mm Hg ±7 mm Hg) and HM+I/R (80 mm Hg±9 mm Hg) were higher than that in I/R (63 mm Hg±9 mm Hg) and ZnPPIX+IPO (65 mm Hg±8 mm Hg) groups (P<0.01). The protein expression of HO-1 in lung tissue was significantly increased in I/R group compared with S group (P<0.01). While the HO-1 protein expression was higher in IPO and HM+I/R groups as compared with I/R group (P<0.05, P<0.01). The lung wet/ dry (W/D) weight ratio and MDA content in serum were significantly increased in I/R group as compared with S or HM+S groups (P<0.01), accompanied by severe lung tissue histological damage, which was attenuated either by IPO or by HM pretreatment (P<0.01, IPO or HM+I/R vs. I/R). The protective effect of IPO was abolished by ZnPPIX. Condusion: Ischemic postconditioning can attenuate the lung ischemia-reperfusion injury through upregulating the protein expression of HO-1 that leads to reduced post-ischemic oxidative damage.     

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.     

Experimental cooling-induced preconditioning attenuates skin flap failure

BACKGROUND: Microvascular perfusion failure is a leading cause of tissue necrosis in reconstructive surgery. In the present experimental study the effect of local hypothermia was investigated as a possible preconditioning procedure that could induce stress proteins such as heat-shock protein (HSP) 70 and HSP-32 (haem oxygenase (HO) 1). The effect on flap microcirculation and survival was also studied. METHODS: Ears of hairless mice were subjected to local hypothermia (30 min, 4 degrees C) 24 h before flap creation. A pedicled flap was elevated by incision of four-fifths of the base of the ear. Microcirculatory dysfunction and tissue necrosis were analysed quantitatively over 5 days by means of intravital fluorescence microscopy. HO-1 and HSP-70 protein expression were determined by western blot analysis. HO-1 distribution within the flap tissue was also analysed by immunohistochemistry. Animals with unconditioned flaps served as controls. RESULTS: Cooling induced a marked expression of HO-1 without induction of HSP-70 protein. This was paralleled by a significant improvement in microvascular perfusion (P < 0.050) that was predominantly regulated by the dilatation of nutritive capillaries. The cooling-mediated improvement in microcirculation resulted in a significant reduction in final flap necrosis (P < 0.050). CONCLUSION: In this experimental study preoperative cooling was associated with the expression of HO-1 and was an effective conditioning procedure.     

血红素氧合酶-1在临床肝移植中肝脏保护作用的研究

目的 研究移植肝脏血红素氧合酶(HO-1)表达水平与缺血再灌注损伤和移植术后肝脏功能的关系.方法 研究28例人类临床原位肝脏移植,根据供肝血红素氧合酶(HO-1)表达的平均值将供肝分为两组:移植前供肝HO-1高表达组和移植前供肝HO-1低表达组.比较两组移植术后血浆AST、ALT水平、胆汁中胆盐含量以及术前术后HO-1 mRNA和蛋白表达情况.结果 再灌注后移植术前HO-1低表达组的HO-1 mRNA表达显著增加,而高表达组HO-1 mRNA表达却有所下降.肝脏移植后,术前HO-1低表达组与高表达组相比,血浆转氨酶显著降低,胆汁中胆盐含量明显高于后者.结论 移植术前HO-1低表达组供肝在再灌注过程中能够进一步诱导HO-1表达,与高表达组供肝相比其所遭受的缺血再灌注损伤较轻,移植术后肝脏功能较好.移植过程中HO-1表达的增强要比移植前HO-1高表达更具有细胞保护作用.免疫荧光染色证实枯否细胞是人类肝脏表达HO-1的主要部位.     

Renal expression of heat shock proteins after brain death induction in rats

The majority of transplanted kidneys are derived from brain-dead patients. This nonphysiological state influences the hemodynamic and hormonal status of the donor. As a result, kidneys derived from brain-dead donors have inferior graft survival and increased graft function loss. Heat shock proteins (HSPs) are a family of stress-inducible proteins involved in maintaining cell homeostasis and regulating the immune system. We studied renal expression of the genes HO-1, HSP27, HSP40, and HSP70 after experimental brain death in rats. Brain death was induced in male F344 rats by slowly inflating a balloon catheter in the epidural space. Untreated rats were used as controls. Animals were humanely killed after 4 hours of brain death. Kidneys were analysed using RT-PCR, Western blotting, and immunohistochemistry. RT-PCR showed an increase in expression of genes coding for HO-1 (3.6-fold; P < .05) and HSP70 (2.7-fold; P < .05) after brain death. Western blotting also revealed an increase in HO-1 protein levels (4.6-fold; P < .001) but changes in HSP70 protein expression were not detected. Immunohistochemistry showed increments of HO-1 protein expression in the renal cortical tubules of brain-dead rats. HSP70 was predominantly increased in renal distal tubules of brain-dead rats treated for hypotension. No changes were observed in renal HSP27 and HSP40 expression after brain death. Renal stress caused by brain death induces expression of the cytoprotective genes HO-1 and HSP70, but not of HSP27 and HSP40. The up-regulation of these cytoprotective genes could be part of a recuperative mechanism induced by stress associated with brain death.