Hyperthermia-induced HSP expression correlates with improved rat renal isograft viability and survival in kidneys harvested from non-heart-beating donors

Transient sublethal hyperthermia followed by recovery from heat stress, referred to as heat shock preconditioning, exerts a protective effect on ischemia/reperfusion-induced injury in many systems. This effect is considered to be correlated to heat shock proteins (HSPs) and might be a critical factor in kidney graft function and survival. This study was designed to examine the impact of heat shock preconditioning on kidney isograft function and survival in a model utilizing non-heart-beating (NHB) donors. Four groups of male Lewis rats (n = 10/group) subjected either to whole body hyperthermia (groups A and C) or to sham anesthesia (groups B and D) were allowed 24 h recovery. Thereafter, 20 min of warm ischemia (A/B), and in a separate set of experiments 40 min of warm ischemia (C/D), were induced by suprarenal aortic cross clamping before renal procurement. After 24-h preservation with University of Wisconsin solution at 4 °C, orthotopic kidney transplantations were performed to syngeneic bilaterally nephrectomized recipients. Tissue specimens were taken to determine HO-1/HSP32, 72, and 90 induction by Western blot analysis. Renal function was measured by means of serum creatinine and creatinine clearance on days 0, 3, and 7 as well as urine volume, protein content, and creatinine levels daily. HO-1/HSP32 and HSP72 were found to be expressed constitutively. Moreover, heat shock strongly induced renal HSP72 and HSP32/HO-1, and to a lesser extent HSP90, expression. For recipients of group A grafts, the graft survival rate was 10/10, whereas it was 7/10 (70 %) in recipients of group B grafts (log rank p < 0.05). Following 40 min of warm ischemia, 6/10 (60 %) recipients survived, whereas all sham treated animals died with anuria within 6 days (log rank p = 0.01). Heat shock preconditioning strongly improved graft viability and reduced functional impairment. Creatinine clearance (CRC) on day 3 post Tx was 0.43 ± 0.24 ml/min in preconditioned animals (group A) and 0.07 ± 0.09 ml/min (p < 0.001) in sham preconditioned (group B), whereas it was 0.91 ± 0.33 ml/min and 0.03 ± 0.02 ml/min (p < 0.00 001) on day 7 post Tx. Following 40 min NHB time, CRC in survivors of preconditioned graft recipients (group C) was 0.32 ± 0.2 ml/min (day 3 post Tx) and 0.23 ± 0.08 ml/min (day 7 post Tx) and was significantly better than CRC of group B (p < 0.01 and p < 0.00001, respectively). CRCs prior to NHB procedures were comparable in all animals ranging between 1.31 and 1.72 ml/min. Serum creatinine as well as proteinuria were significantly increased after transplantation in both groups but recovered within 5 days in recipients of preconditioned grafts, whereas kidneys from donors without HP did not recover function. Histological alterations were also diminished following HP. Hyperthermic preconditioning induces strong and long lasting HO-1/HSP32, HSP72, and HSP90 expression in rat kidneys. HP increases survival following transplantation and improves renal graft function including proteinuria, volume output, and creatinine clearance. HSP induction might be used to develop novel approaches in clinical transplantation. Received: 3 November 2000 Revised: 27 February 2001 Accepted: 29 May 2001     

Heme oxygenase-1 attenuates ischemia/reperfusion-induced apoptosis and improves survival in rat renal allografts

BACKGROUND: Kidneys can be preserved only for a limited time without jeopardizing graft function and survival. Induction of heat shock proteins (HSPs) can protect against ischemia/reperfusion (I/R) injury. Therefore, we investigated whether the induction of the HSP, heme oxygenase-1 (HO-1), improves outcome following isotransplantation after an extended period of cold storage. METHODS: Rats were subjected to heat preconditioning (HP; 42 degrees C for 20 minutes). Kidneys harvested after 24 hours, were preserved in cold University of Wisconsin (UW) solution at 4 degrees C for 45 hours and transplanted into bilateral nephrectomized rats. Cobalt protoporphyrin (CoPP) was administered in another group of animals in order to induce HO-1 pharmacologically, while other groups of animals received the HO-1 inhibitor, tin protophorphyrine (SnPP), following HP or CoPP. RESULTS: Cold ischemia caused a complete attenuation of graft function within 3 days following transplantation and subsequent death of all animals, whereas HP protected graft function and five of nine rats survived for 3 weeks. HP inhibited the induction of osteopontin and induced the expression of HO-1, HSP 70 and 90, and the antiapoptotic factor Bcl-XL. Grafts exposed to HP were protected against structural I/R injuries as revealed by histologic assessment using a semiquantitative score. Furthermore, induction of apoptosis was attenuated and activation of caspase-3 was inhibited. Comparable results were observed after administration of CoPP, whereas SnPP inhibited the effects of HP and CoPP. CONCLUSION: HP or administration of CoPP induced both HO-1, preserved kidney graft function, and prevented postreperfusion apoptosis after cold preservation.     

Improved skin flap survival after local heat preconditioning in pigs

BACKGROUND: Preconditioning induces the expression of heat shock proteins (HSPs), which can help a cell survive an acute episode of stress. Similar to the induction of HSP expression, the cell protection is independent of the type of stress. The aim of this study was to test in a large, randomized animal model, if skin flap survival may be improved by local heat preconditioning and induction of HSP 70. MATERIALS AND METHODS: Twenty-four hours before surgery, a heating blanket was laid on the buttocks of large white pigs. In the preconditioned group (n = 6), the blanket was warmed up to 43 degrees C for 3 x 30 min, whereas it was kept at room temperature in between the heating episodes as well as in the control animals (n = 6). A random pattern skin flap was raised on both sides of the buttocks. Flap survival was measured clinically. Induction of HSP and apoptosis were assessed quantitatively by immunohistochemistry and TUNEL assay, respectively. RESULTS: Preconditioning reduced flap necrosis from 40 +/- 8% of the total flap surface to 7 +/- 14% (P < 0.01). Induction of HSP was significantly higher in the experimental group (79 +/- 12% versus 42 +/- 13%, P < 0.01), whereas apoptosis in healthy flap tissue was reduced from 30 +/- 11 to 11 +/- 6 cells/visual field (P < 0.01). CONCLUSION: In the present study, necrosis and apoptosis rate of skin flaps could be reduced significantly due to local heat preconditioning. Our results suggest that ischemia-related wound healing complications could be diminished with local heat application, a most simple and least invasive method of preconditioning.     

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     

Prior induction of heat shock proteins by a nitric oxide donor attenuates cardiac ischemia/reperfusion injury in the rat

BACKGROUND: Recent studies have demonstrated that nitric oxide (NO) releasers considerably increase heat shock proteins (HSPs) in the in vitro cell system, providing resistance to oxidant damage. This study was designed to examine the cellular responses of HSPs induced by prior administration of an NO releaser, FK409 (FK), in an in vivo transplantation model. METHODS: Lewis rats received either saline or FK solution intravenously administered at different time points before graft harvesting (10 micromol/kg) or for 15 min during reperfusion (0.66 micromol/kg/min). Tissue specimens were taken to determine HSP70 and heme oxygenase-1/HSP32 (HO-1) expression, and glutathione content. After 24-hr preservation with University of Wisconsin solution, heterotopic cardiac transplantations were performed, and graft survival was determined at 14 days. Tissue samples for end labeling of nuclear DNA fragments (TdT-mediated d-uridine triphosphate biotin nick end labeling; TUNEL) and propidium iodide staining were taken 15 min after reperfusion. RESULTS: The gene and protein expression of HSP70 after FK administration peaked at 12 min and 60-90 min, whereas those of HO-1 peaked at 6 min and 90 min, respectively. Then, representative cardiac grafts taken 60 min after FK treatment were examined for further assay. Localization of induced HSP70 and HO-1 molecules were observed in the myocardium and vascular endothelium, respectively. Prior treatment of FK was effective in preventing the reduction of tissue glutathione contents compared with control (P<0.05). Fewer TUNEL and propidium iodide-positive cells were also observed in the FK group (P<0.0005, vs. control). The graft survival rate was higher in the FK group (9/10 vs. 1/10 of control; P<0.001), whereas the groups either harvested 10 min after FK pretreatment or continuously infused for 15 min during reperfusion were inferior, similar to that of control. CONCLUSION: Prior induction of HSP70 and HO-1 with a relatively low dose of FK administration attenuates ischemia and reperfusion injury, which was due to antioxidant and antiapoptotic activities augmented by such stress proteins. Thus, NO releasers as a pharmacological maneuver may provide an innovative approach for the prevention of ischemia and reperfusion injury.     

热休克蛋白70抑制大鼠颅脑损伤诱生型一氧化氮合酶mRNA的表达

目的 探讨热休克蛋白７０（ＨＳＰ７０）对大鼠感染性脑损伤（感脑）诱生型一氧化氮合酶（ｉＮＯＳ）的表达及一氧化氮（ＮＯ）合成的影响。方法 将大鼠７２只随机分为正常对照组、感染性脑损伤组和热休克处理组,每组又ｈ共３个时间点。采用百日咳菌液通过左颈内动脉注入制成大鼠感染性脑损伤模型,用Ｗｅｓｔｅｒｎ印迹杂交技术检测各组各时间点的ＨＳＰ７０的表达,同时用原位杂交方法检测各组ｉＮＯＳｍＲＮＡ的表达及Ｇｒｉｅｓｓ法测定各组的ＮＯ含量的变化。结果 Ｗｅｓｔｅｒｎ印迹杂交分析结果表明,大鼠感脑各组及正常组有一定量的ＨＳＰ７０表达,而热休克处理组的ＨＳＰ７０的量明显高于感脑组（Ｐ〈０．０１）。原位杂交结果提示ｉＮＯＳ在感脑的大脑皮质神经细胞４、８、２４ｈ开始表达,可见明显的杂交信号,而休克处理组仅有少量的阳性颗粒。ＮＯ含量在感脑     

热休克蛋白70对肾脏缺血预处理保护作用的研究

目的 :研究缺血预处理对肾脏缺血再灌注损伤的保护作用 ,观察热休克蛋白 70 (HSP70 )的表达变化并探讨其作用机制。方法 :建立大鼠肾脏缺血再灌注损伤模型并进行缺血预处理 ,实验分组 :假手术组 (S组 )、缺血再灌注组 (IR组 )和缺血预处理组 (PC组 )。各组再灌注后检测血清肌酐 (Scr)、肾组织丙二醛 (MDA)含量 ,肾组织石蜡切片苏木精伊红染色以及免疫组化染色。结果 :PC组Scr值、肾小管病理评分、肾组织中MDA含量明显低于IR组 (P <0 .0 5 ) ,PC组与S组比较差异无显著性意义 (P >0 .0 5 ) ;HSP70免疫组化染色 :S组未见明显的阳性反应产物 ,PC组和IR组肾小管上皮细胞胞质可见棕黄色阳性反应产物。计算机图像分析显示PC组灰度值显著高于IR组 (P <0 .0 1)。结论 :缺血预处理对肾脏缺血再灌注损伤有明显保护作用 ,其作用机制可能与HSP70本身的细胞保护作用及HSP70的细胞内抗氧化作用有关     

不同预处理对肝硬化兔缺血再灌注肝组织HSP70及ET-1表达的影响

目的:探讨两种预处理方式,即经典缺血预处理(IPC)与肢体缺血预处理(LIPC),对肝硬化兔肝缺血再灌注(I/R)损伤的保护作用及可能的作用机制。方法:皮下注射CCl4-橄榄油溶液制备兔肝硬化模型,随后将模型兔随机分为假手术组,肝I/R组(I/R组),IPC+肝I/R组(IPC组),LIPC+肝I/R组(LIPC组),每组7只。肝I/R模型制作方法:阻断入肝血流30 min,再灌注2 h;IPC诱导方法:在行肝I/R处理前阻断入肝血流10 min,开放10 min;LIPC诱导方法:在行肝I/R处理前24 h,采用止血带捆扎兔单侧后肢5 min,再开放5 min,重复3次。各组于再灌注2 h后切取肝组织,行组织形态学观察,用ELISA法测定内皮素1(ET-1)含量及Western blot法检测热休克蛋白(HSP70)的表达。结果:与假手术组比较,其余各组在肝硬化病变的基础上均出现不同程度的变性、水肿和炎性细胞浸润,但IPC组与LIPC组明显轻于I/R组,而LIPC组及IPC组间病变程度无明显差异;与假手术组比较,其余各组肝组织ET-1含量和HSP70的表达均明显增加(均P<0.05),但IPC组与LIPC组肝组织ET-1含量低于I/R组,HSP70的表达高于I/R组(均P<0.05),而上述2项指标在LIPC及IPC组间均无统计学差异(均P>0.05)。结论:LIPC和IPC均能对肝硬化肝I/R损伤有保护作用,且保护强度相似,其机制可能均与抑制ET-1的释放及增加HSP70的表达有关;LIPC具有无创性,可能具有更大的临床应用前景。     

Intramuscular heat shock protein 72 and heme oxygenase-1 mRNA are reduced in patients with type 2 diabetes: evidence that insulin resistance is associated with a disturbed antioxidant defense mechanism

To examine whether genes associated with cellular defense against oxidative stress are associated with insulin sensitivity, patients with type 2 diabetes (n = 7) and age-matched (n = 5) and young (n = 9) control subjects underwent a euglycemic-hyperinsulinemic clamp for 120 min. Muscle samples were obtained before and after the clamp and analyzed for heat shock protein (HSP)72 and heme oxygenase (HO)-1 mRNA, intramuscular triglyceride content, and the maximal activities of beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) and citrate synthase (CS). Basal expression of both HSP72 and HO-1 mRNA were lower (P < 0.05) by 33 and 55%, respectively, when comparing diabetic patients with age-matched and young control subjects, with no differences between the latter groups. Both basal HSP72 (r = 0.75, P < 0.001) and HO-1 (r = 0.50, P < 0.05) mRNA expression correlated with the glucose infusion rate during the clamp. Significant correlations were also observed between HSP72 mRNA and both beta-HAD (r = 0.61, P < 0.01) and CS (r = 0.65, P < 0.01). HSP72 mRNA was induced (P < 0.05) by the clamp in all groups. Although HO-1 mRNA was unaffected by the clamp in both the young and age-matched control subjects, it was increased (P < 0.05) approximately 70-fold in the diabetic patients after the clamp. These data demonstrate that genes involved in providing cellular protection against oxidative stress are defective in patients with type 2 diabetes and correlate with insulin-stimulated glucose disposal and markers of muscle oxidative capacity. The data provide new evidence that the pathogenesis of type 2 diabetes involves perturbations to the antioxidant defense mechanism within skeletal muscle.     

阿霉素预处理替代缺血预处理提供鼠肝缺血耐受力的实验研究

目的 探讨缺血预处理（IPC）延迟保护作用的发生机制以及应用阿霉素预处理（DPC）是否可以模拟IPC的延迟保护作用。方法 建立大鼠部分肝脏热缺血再灌注模型。IPC组采用肝脏缺血10min，再灌注10in，DPC组经静脉注射阿霉素（1mg/kg体重），对照组等量生理盐水注射。肝组织HSP70和HO－1蛋白和血清TNF－α、IL－10浓度分别采用Western blot法和ELISA法测定。结果 IPC后HO－1和HSP70含量分别于12h和24h达到高峰；IPC和DPC后24h诱导HSP70、HO－1的量无显著差异（P＞0.05）。对照组缺血再灌注后3h血清中TNF－α、AST、ALT、LDH及W／D（湿重／干重）的水平明显升高，而IL－10的含量降低，和假手术组相比差异显著（P＜0.01）；IPC或DPC后降低了TNF－α的释放和AST、ALT、LDH及W／D的水平，提高了IL－10的含量，和对照组相比差异显著（P＜0.01）。结论 IPC的延迟保护作用与HSP70和HO－1的诱导生成有关，DPC可以模拟IPC的延尺性保护作用，诱导HSP70和HO－1的产生。     

Welcoming a New Hip into the Family

ABSTRACT

Introduction: The aim of this study is to evaluate whether hemorrhage and resuscitation affect liver, intestinal, and renal expressions of heat shock protein 70 (HSP70), inducible nitric oxide synthase (iNOS), and apoptosis indexes (TUNEL, caspase-3 activation) and whether the expression of these proteins can be modulated by pyrrolidine dithiocarbamate (PDTC) after a nonlethal hemorrhagic shock (HS) in rats. Methods: Forty rats were randomized into four groups: sham-operated, only HS, HS/resuscitation with blood plus normal saline (NS), and HS/resuscitation with blood/NS plus PDTC, 15 mg/kg body weight, intravenously. Rats were subjected to HS by blood removal to a mean arterial pressure of 35–40 mmHg through the femoral artery. After 1 hr of shock, the animals were resuscitated according to the experimental protocol. HSP70, iNOS, cleaved caspase-3 expression, and TUNEL were analyzed in liver, small intestine, and kidney 3 hr after resuscitation. Results: HS upregulated HSP70, iNOS, cleaved caspase-3 expression, and induced apoptosis (TUNEL) (p < .05 to < .001). Resuscitation was not associated with further increase of their expressions. The administration of PDTC during resuscitation decreased liver, intestinal, and renal activation of iNOS and apoptosis indexes (p < .05 to < .001), and was associated with further increase in HSP70 expression (p < .05). Conclusions: Our results show that HS resuscitation with PDTC modulates several signaling pathways (HSP70, iNOS, TUNEL, and caspase-3) in a rat model. The results suggest that PDTC administration—by reducing apoptosis and iNOS expression—may have a potential role in minimizing organ damage after severe hemorrhage.     

Heat-shock preconditioning protects fatty livers in genetically obese Zucker rats from microvascular perfusion failure after ischemia reperfusion

Reduced tolerance of steatotic livers to ischemic injury is considered to correlate with impaired microcirculation. The aim of this study was to investigate the impact of heat-shock preconditioning (HSPC) on microcirculatory failure after ischemia/reperfusion (I/R) in steatotic livers by means of intra-vital fluorescence microscopy. Obese Zucker rats were used. In the HS group, rats underwent whole-body hyperthermia followed by 60-min partial liver ischemia. In group IR, rats were exposed only to ischemia. Microcirculation parameters (sinusoidal perfusion rate, sinusoidal diameter, leukocyte-endothelial interaction) were significantly better preserved in the HS group than in the IR group. Liver enzymes, oxygenated glutathione/reduced glutathione (GSSG/GSH) ratio, and electron microscopy showed less damage in the HS group. A marked expression of heat shock protein 72 (HSP72) and heme oxygenase (HO-1) was found only in the livers of group HS. HSPC mitigated the I/R injury of steatotic livers by preventing post-ischemic failure of microcirculation. This beneficial effect was found to be associated with the induction of HSP72 and HO-1.     

Heat preconditioning ameliorates hepatocyte viability after cold preservation and rewarming, and modulates its immunoactivity

BACKGROUND: Heat preconditioning significantly preserved liver graft function after cold preservation in animal experimental model. The elevation of heat shock protein 70 (HSP70) was claimed to play a critical role in protecting grafts against cold preservation-induced hepatocyte apoptosis. However, little is known about whether HSP70 also plays an immunomodulatory role in cold preserved cells. This study aimed at investigating the relationship between HSP70 protein and the immunoactivity in response to lipopolysaccharide (LPS) stimulation. METHODS AND RESULTS: A normal rat hepatocyte cell line was preserved with University of Wisconsin (UW) solution, Ringer's lactate solution (RL), and phosphate-buffered saline (PBS) at 4 degrees C. No significant morphological alteration was noted in UW-preserved cells after 24 h through phase-contrast microscopic observation and fluorescent viability stain. Western blotting showed a two-fold increase in the ratio of HSP70/Bax proteins in cells after 24 h of UW preservation. Heat preconditioning significantly enhanced the recovery of lactate dehydrogenase (LDH) activity in both RL- and UW-preserved cells that were stored for a period of 12 h or less. Moreover, heat preconditioning promoted HSP70 and NF-kappaB p50 nuclear translocation and suppressed the LPS-induced nuclear p50 accumulation in cells before UW preservation. Immunofluorescent stain revealed that the LPS-induced p50 protein redistribution to nuclear membrane might contribute to NF-kappaB activation, while heat preconditioning and UW cold preservation completely abrogated the p50 intranuclear redistribution. Thus NF-kappaB p50 might be responsible for the endotoxin tolerance induction. CONCLUSIONS: These findings strongly suggest that heat preconditioning not only preserves hepatocyte viability after cold preservation and rewarming, but also ameliorates its immunoactivity.     

Enhancement of heat shock protein expression after transient ischemia in the preconditioned spinal cord of rabbits

Purpose: This investigation was designed to evaluate the mechanism used to acquire a tolerance to spinal ischemia. We investigated inductions of the heat shock protein (HSP) 70 gene and protein in rabbit spinal cord with or without preconditioning. Methods: Neurologic function, morphologic changes, and inductions of HSP70 messenger RNA (mRNA) and protein were compared in the cases of a 15-minute ischemia 2 days after sham treatment and a 15-minute ischemia 2 days after 10-minute preconditioning. Result: HSP70 mRNA was induced at 8 hours of reperfusion after a 15-minute ischemia 2 days after sham treatment. HSP70 protein was induced slightly in selective motor neuron cells at 8 hours of reperfusion, and about 70% of motor neuron cells showed selective cell death after 7 days of reperfusion (p < 0.01). On the other hand, large populations of the motor neuron cells survived at 7 days after the 15-minute ischemia that was applied at 2 days after preconditioning (p < 0.01). HSP70 mRNA was induced persistently as compared with the case of a 15-minute ischemia 2 days after sham treatment. The motor neuron cells strongly produced immunoreactive HSP70 from 8 hours to 2 days. Conclusion: Preconditioning with 10-minute ischemia enhanced and prolonged the HSP70 gene expression at both mRNA and protein levels and saved the motor neuron cells from subsequent lethal ischemia. These changes of HSP70 gene expression may play an important role in the acquisition of ischemic tolerance of motor neuron cells in rabbit spinal cord. (J Vasc Surg 1998;27:720-5.)     

皮瓣重建兔阴囊诱导精原细胞凋亡与热休克蛋白70表达

目的:探讨皮瓣重建阴囊后睾丸表面的温度变化、生精细胞凋亡及热休克蛋白70(HSP70)的表达。方法:以健康育龄期新西兰大白兔为实验动物,雄性24只、雌性12只。将雄兔随机分成实验组12只,对照组12只。采用温度计埋藏法测量实验组阴囊内睾丸表面的温度,手术切除实验组动物阴囊,建立皮瓣重建阴囊动物模型,对照组未作处理。动物模型建立后第8周末对照组随机取6只动物进行睾丸活检,实验组随机取6只动物测量睾丸表面温度后行睾丸活检。睾丸组织行HE染色、原位末端标记(TUNEL)法检测生精细胞凋亡、免疫组化法结合图象分析仪检测睾丸生精细胞HSP70的表达。模型建立后第8周末,将两组未行睾丸活检的各6只动物分别与雌兔配对喂养观察生育情况。结果:实验组模型建立前睾丸表面温度为(36.0±0.3)℃,模型建立后第8周末睾丸表面温度为(38.1±0.6)℃(P<0.05)。模型建立后第8周末实验组睾丸生精小管中生精细胞的凋亡指数(AI)为(71.85±2.69)%,对照组为(7.73±4.95)%(P<0.05)。对照组HSP70主要在圆形精子细胞中表达,实验组主要表达在精原细胞。配对喂养结果显示,实验组没有生育,对照组生育幼兔(6.0±1.3)只(P<0.05)。结论:皮瓣重建家兔阴囊后睾丸局部温度升高诱导生精细胞凋亡增加,动物丧失生育能力。HSP70参与保护皮瓣重建阴囊诱导的精原细胞凋亡。     

子宫内膜癌热休克蛋白70、90的表达及其临床意义

目的 :探讨子宫内膜癌中热休克蛋白 ( HSP) 70、90的表达及意义。方法 :用免疫组化 Envision法及图象分析仪检测了 3 0例正常子宫内膜、3 0例增生过长子宫内膜和 53例子宫内膜癌中 HSP70、90的表达情况。结果 :子宫内膜癌中 HSP70的表达为( 2 0 9.0 6± 5.3 6 ) ,明显高于正常内膜 ( 1 45.2 1± 4.0 9)和增生过长内膜 ( 1 48.59± 4.2 3 ) ,P均 <0 .0 1 ;子宫内膜癌中 HSP90的表达为 ( 1 6 6 .98± 5.71 ) ,明显低于正常子宫内膜( 2 0 8.57± 3 1 .1 4)和增生过长子宫内膜 ( 2 49.73± 4.94) ,分别为 P<0 .0 5、P<0 .0 1。子宫内膜癌中 HSP70表达随肿瘤病理分级升高而增强 ( P<0 .0 1 ) ,非内膜样癌较内膜样癌表达增强 ( P<0 .0 1 ) ;子宫内膜癌中 HSP90表达随肿瘤病理分级升高而表达减弱 ( P<0 .0 1 ) ,非内膜样癌较内膜样癌表达减弱 ( P<0 .0 1 )。但子宫内膜癌中 HSP70、90表达与肌层浸润深度、术后病理分期、淋巴结转移未见显著相关性 ( P>0 .0 5)。结论 :HSP70、90可能与子宫内膜癌发生及预后有关     

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.