Protective effect and mechanism of KATP channel opener on the sinoatrial node cells of neonatal rat cultured in simulated ischemia-reperfusion＊

Objective: To study the effect of KATp channel opener and its possible mechanism on the sinoatrial node cells of neonatal rats which were cultured under simulated ischemia-reperfusion. Methods: Freshly isolated sinoatrial node (SAN) cells of neonatal rats were purified and cultured for 2 d, and then they were randomly divided into the control, simulated ischemia-reperfusion group (I/R group) , group intervened with KATp channel opener pinacidil (P + I/R group), KATP Channel blocking agent 5-HD (5-HD + I/R group) , and group with the 2 agents at same time (5-HD + P + I/R group) . The survival rate of cells was measured by flow cytometry and the content of intracellular calcium in the cells of each group was detected with laser confocal microscopy. Results: ① The survival rate of SAN cells in I/R group [ (51. 79±6. 28)% ] was remarkably significantly lower than in control [ (95. 08±10. 48)% ] (P < 0.001), and very significantly lower than in P + I/R group [ (63. 77±5. 35) % ] (P<0.01), however, those     

Zinc is a potent heat shock protein inducer during liver cold preservation in rats

Objective A simple liver cold preservation model was established to study the synthesis of heat shock protein 70 (HSP70) induced by zinc (ZnSO［4］,i.p.) and its protection during liver cold preservation in rat.Methods Male Wistar rats were divided into 5 groups (n=6).In control group rat received no pretreatment; in Zn-1 group, Zn-2 group, and Zn-3 group rats were pretreated with zinc sulfate at a dose of 5 mg/kg, 10 mg/kg, 15 mg/kg respectively; and in H group rat received heat shock preconditioning (42.5℃×15 min).Livers were preserved in UW solution for 6, 12 and 24 h, respectively.HSP70 was analyzed by Western blot.Aspartate transaminase (AST) and lactate dehydrogenase (LDH) values of the perfusion solution and the histology of the liver were evaluated.Results HSP70 expression was markedly elevated after pretreatment with zinc and heat shock.AST and LDH values in the Zn-1, Zn-2 and H groups were significantly lower than those in the control group, respectively (P&lt;0.05).There was no significant difference among the three groups (P&gt;0.05), whereas the AST and LDH values in the Zn-3 group were much higher than those in the control group.Histology results showed that liver injury in the Zn-1, Zn-2 and H groups were minimal, while it was severe in the Zn-3 group.Conclusions Zn(2+) is a potent and feasible inducer of HSP expression and is able to protect liver from cold preservation injury.The proper inducing dosage of Zn(2+) ranged from 5 mg/kg to 10 mg/kg.The dosage of 15 mg/kg for Zn(2+) as a HSP inducer is not indicated for its severe toxicity to the liver.     

ROS-mediated ERK activation in delayed protection from anoxic preconditioning in neonatal rat cardiomyocytes

Background The activation of extracellular signal-regulated kinase1/2 (ERK1/2) has been shown to be important signaling pathway in the ischemic preconditioning (IPC) response. Recently, some studies suggest a key role for the mitochondrial ATP-sensitive potassium channel (mKATP) as both a trigger and an end effector of acute and delayed protection of IPC. Hence, this study was undertaken to elucidate the relationship between mKATP and ERK1/2 in the delayed protection mechanism of anoxic preconditioning (APC). Methods An APC model was established using cultured neonatal rat cardiomyocytes. Pharmacological agents ［diazoxide, 5-hydroxydecanoate (5-HD), 2-mercaptopropionylglycine (MPG), and PD98059］ were used to modulate mKATP and ERK1/2 activation. Cellular injury was evaluated by measuring cellular superoxide dismutase (SOD) activity, cell viability, and lactate dehydrogenase (LDH) release. The generation of cellular reactive oxygen species (ROS) and the activation of ERK1/2 were determined at different time points starting from the beginning of preconditioning with anoxia or diazoxide (an mKATP opener). Results Cell viability and SOD activity in the APC ［(81.9±11.4)%, （13.6 ± 3.7） U/L］ and diazoxide ［(79.2±12.4)%, （16.5±4.6） U/L］ groups were significantly higher than in the anoxia/reoxygenation (A/R) ［(42.2±7.3)%, （8.8±2.8） U/L］ group (all P&lt;0.01). LDH activity in the APC group ［(101.9±18.9) U/L］ and diazoxide group ［(97.5±17.7) U/L］ was significantly lower than in the A/R group ［(250.5±43.6) U/L］ (all P&lt;0.01). Both APC and diazoxide simultaneously facilitated intracellular ROS generation and rapid ERK1/2 activation. But the effects of APC and diazoxide were remarkedly attenuated by 5-HP (an mKATP blocker) and by MPG (a free radical scavenger). In addition, the ERK1/2 inhibitor PD98059 also abolished the cellular protective effects induced by diazoxide. Conclusion mKATP may mediate ERK1/2 activation during anoxia preconditioning by generating ROS, which then triggers the delayed protection of APC in rat cardiomyocytes.     

The antiapoptotic effect of insulin against anoxia/reoxygenation injury in cultured cardiomyocyte of neonatal rat

Objective： To study protective effect of insulin against cardiomyocyte apoptosis in anoxia/reoxygenation （A/R） injury of neonatal rat. Methods： The model of A/R injury was finished through receiving anoxia for 2h and reoxygenation for 4h in cultured cardiomyocytes of neonatal rat. The cardiomyocytes were divided randomly into 3 groups： control group （CON）, anoxia/reoxygenation group （A/R） and insulin-treated group （INS）. At the end of reoxygenation of 4 hours, activities of lactate dehydrogenase （LDH）, contents of malondiaidehyde （MDA）, were assessed through spectrophotometric procedures, myocyte apoptosis were detected through TUNEL and DNA Ladder. Results： MDA, LDH, and Apoptosis Index were significantly decreased in INS group compared with A/R group （P〈0.01）. Conclusion： Insulin has a protective effect against A/R injury in cultured cardiomyocyte of neonatal rat; the protective mechanism may contribute to antiapoptosis of insulin.     

Genotypes and polymorphisms of mutant CCR5-△32,CCR2-64I and SDF1-3’A HIV- 1 resistance alleles in indigenous Han Chinese

Objective To understand the interaction between surfactant proteins and pneumocys tis carinii pneumonia (PCP), and the impact of corticosteriods on surfactant proteins.Methods We established rat models of PCP and bacterial pneumonia induced by subcutaneous injection of 25mg cortisone acetate. At 8-12 wk, the bronchoalveolar lavage f luid (BALF) of rats was collected. Total nucleated cells of BALF were counted a nd differentiated, and the concentrations of surfactant protein A (SP- A) and su rfactant protein D (SP- D) were measured by immunoblotting assay. The rats were divided into three immunosuppressive groups and a normal control group. Group Ⅰ, normal control (n=6), consisted of healthy SD rats; group Ⅱ, negative cont rol (n=6), consisted of rats with cortisone acetate injection for over 8 wk with out lung infection; group Ⅲ, bacterial pneumonia (n=11), rats were injected wit h cortisone acetate over 8 wk that resulted in bacterial pneumonia without other pathogens isolated; and group Ⅳ, PCP (n=14), rats with injected cortisone acet ate for 8-12 wk and developed PCP without other pathogens isolated. Results Our results indicated that the total cell count in BALF in the negative control group was lower than that in the normal control group (P&lt;0.001). During P CP infection, the total cell count and the percentage of polymorphonuclearcytes (PMNs) in BALF were signi ficantly increased (P&lt;0.01), but were lower than those in the bacterial pne umonia group. The concentration of SP- A of BALF in PCP (45.1±22.1 μg/ml) was significantly increased in comparison with that in the negative control ( 16.2±9.9 μg/ml, P&lt;0.05) and bacterial pneumonia groups (6.2±5.6 μ g/ml, P&lt;0.001). We also found that the relative content of SP - D was signi ficantly higher in PCP (24 249±4780 grey values) than that in the negative control (13 384±2887 grey values, P&lt;0.001) and that in bacterial pne u monia (11 989±2750 grey values, P&lt;0.001). SP- A and SP- D were a lso higher in the moderate to heavy group of PCP than those seen in the mild group (P&lt;0.01, P&lt;0.001). SP- A and SP- D were higher in the negative contr ol group than those in the normal control group, but there was no significant di fference between the 2 groups. Conclusion These results suggest that the concentrations of SP- A and SP- D in BALF are inc reased by pneumocystis carinii specific stimulation, but the alteration is n ot related to the corticosteriod usage.     

Enhanced sensitivity to mitomycin C by abating heat shock protein 70 expression in human bladder cancer cell line of BIU-87

Background Bladder cancer is a relatively common tumor in the urinary system, in which mitomycin C (MMC)-based chemotherapy or combination chemotherapy has been mainly used to treat patients with advanced bladder cancer. The prognosis of patients with advanced bladder cancer is still extremely poor in spite of recent therapeutic advances. To improve the prognosis, the sensitivity of tumor cells to mitomycin C by the induction of apoptosis with the abating heat shock protein 70 (HSP70) expression in human bladder cancer cell lines of BIU-87 was investigated. Methods HSP70 expression was abated in BIU-87 cells by HSP mRNA antisense oligomers. MTT assay and the clone-forming test were used for evaluating the sensitivity of cells to MMC. Apoptosis was assessed using both fluorescent microscopy after staining the cells with Hoechst 33258 and DNA fragment ladder agarose electrophoresis. Thirty-two male six-week-old BALB/c nude mice, at the beginning of the experiment, were used to evaluate the effect of antisense oligomers (ASO) on the tumor formation in vivo. Results HSP70 expression in BIU-87 was effectively abated by HSP70 mRNA antisense oligomers. The percentage of apoptotic cells in ASO group was greater than in sense oligomers (SO) ［P&lt;0.05, （18.31±2.89）% vs （1.89±0.74）%］, nonsense oligomers (NO) ［P&lt;0.05, （18.31±2.89）% vs （1.78±0.92）%］ and blank groups ［P&lt;0.05, （18.31±2.89）% vs （1.87±0.84）%］, while the sensitivity of tumor cells to mitomycin C was enhanced. The in vivo tumor inhibition rate of ASO plus MMC (&gt;50%) was more than that of ASO or MMC group alone (all P&lt;0.05). Conclusions The abating level of HSP70 expression can strengthen the sensitivity of BIU-87 to MMC. One of this effect might be related to the induction of apoptosis by abating HSP70 expression. Chin Med J 2005; 118(23):1965-1972     

Electron paramagnetic resonance in monitoring of nitric oxide production after kidney transplantation in rats

Background Much research has been focused on ischemia/reperfusion injury (IRI) to the transplanted organs. As a free radical, nitric oxide （NO） plays an important role in IRI. In this study, the production of NO and its functions during IRI were monitored in rat models after allotransplantation of kidney grafts.Methods Of 75 male LEW rats, 30 served as donors, and the remaining 45 rats were divided into three groups (15 rats in each group): controls (group 1), kidney allotransplantation followed by bilateral nephrectomy during reperfusion (group 2), 2 hours before operation, donors and recipients were treated with N（G）-nitro L-arginine methyl ester (L-NAME), a NO synthase inhibitor, at a dose of 30 mg/kg (group 3). Bilateral nephrectomies were performed while kidney grafts were reperfused. The kidney grafts were hypothemically stored for 24 hours. The production of NO before and after reperfusion was measured by electron paramagnetic resonance (EPR). The creatinine level, the glomerular filtration rate (GFR) and the protein carbonyl content in tissue samples were recorded on the first and the fifth day after operation. The data were evaluated by one-way analysis of variance. Differences were considered to be statistically significant when a P value was less than 0.05.Results After reperfusion for 15 minutes, the production of NO increased remarkably and kept increasing till 120 minutes, after which the level returned to normal. In group 3, which was pretreated with L-NAME, creatinine levels were higher than those in group 2 at the 24th hour (4.10±0.50 mg/dl vs. 3.77±0.42 mg/dl, P&lt;0.05) and the 120th hour (3.19±0.79 mg/dl vs. 2.22±0.53 mg/dl, P&lt;0.05). GFR levels in group 3 were lower than those in group 2 at the 24th hour (0.50±0.12 ml/min vs. 0.71±0.19 ml/min, P&lt;0.05) and the 120th hour (0.59±0.38 ml/min vs. 1.27±0.23 ml/min, P&lt;0.01). The content of protein carbonyl in tissue samples of group 3 was lower than that in group 2 at the 24th hour (29.01±7.02 nmol/mg protein vs. 49.39±13.13 nmol/mg protein, P&lt;0.05), but was higher than that at the 120th hour (75.71±16.74 nmol/mg protein vs. 57.93±15.32 nmol/mg protein, P&lt;0.05).Conclusions After transplantation of hypothemically stored kidney grafts, the increased NO production in the early stage has protective effects on the transplanted kidney. Application of L-NAME to inhibit NO production is harmful to the recovery of the renal functions of kidney grafts.     

A STUDY OF α-1,4-GLUCOSIDASE ACTIVITY IN HUMAN SEMINAL PLASMA

The activity of α-1, 4-glucosidase in seminal plasma from 105 fertile Chinese was 42.7±2.0 mIU/ml and 136.5±8.1 mIU/total. The specific activity was 874.3±84.0 mIU/g protein. There was a significantly positive correlation between the activity (mIU/ml) and the number of spermatozoa. The activity for infertile group was lower than that of the fertile group. For the azoospermia group, the activity was 28.7±3.4 mIU/ml and 47.8±4.9 mIU/total (n=29). There was a significant difference as compared with that of fertile group. The enzyme activity of varicocele group was 35.6±5.1 mIU/ml and 120.3±13.6 mIU/total (n=18). It was higher than that of the azoospermia group (P<0.001). There was no significant difference between the varicocele group and the fertile group. The possible role of the enzyme in seminal plasma and the significance of measurement of the activity in clinical investigation are discussed briefly.     

热休克蛋白70基因转染抗心肌细胞凋亡对缺氧/复氧损伤的保护作用

目的 观察比较热休克蛋白70对心肌细胞急性实验性缺氧/复氧损伤的保护作用及其与热休克心肌细胞保护模型之间作用的异同.方法 进行大鼠乳鼠原代心肌细胞培养,分为4组:空白组(对照),缺氧/再灌组(A/R),热休克蛋白组(A/R+HS)和pCDNA热休克蛋白质粒组(pCDNA HSP70).用脂质体对pCDNA HSP70质粒包裹,并转导入相关心肌细胞内.RT-PCR检测HSP70 mRNA表达、Western印迹检测HSP70蛋白质表达.检测心肌细胞存活率(四甲基偶氮唑蓝比色法)、培养液中乳酸脱氢酶活性、心肌细胞超微结构改变(透射电镜)及凋亡指数观察心肌细胞损伤程度.结果 A/R+HS组和A/R+pCDNA HSP70组细胞存活率显著提高(71.8±10.3)%、(73.4±12.2)%;(LDH)活性明显降低(14.3±2.6)IU/L、(14.6±2.9)IU/L;细胞超微结构明显改善;A/R组的HSP7o mRNA和蛋白质含量比A/R+HS组和A/R+pCDNA HSP70组,明显偏低(1.87±0.23、2.05±0.34倍P＜0.01).二者的细胞凋亡指数也较A/R组明显降低.结论 HSP70基因高表达能对抗缺氧/复氧对心肌细胞的损伤,其作用与抗细胞凋亡有关.     

含有人热休克蛋白基因的重组腺病毒转染乳鼠心肌细胞的实验研究

目的:研究含有人热休克蛋白70(HSP70)基因的重组腺病毒对乳鼠心肌细胞的转染效率以及基因转染后HSP70的表达。方法:体外原代培养乳鼠心肌细胞,以携带增强绿色荧光蛋白(EGFP)基因的腺病毒载体(Ad.EGFP)按不同感染倍数(MOI)体外感染心肌细胞,通过荧光显微镜、流式细胞仪观察所构建的腺病毒的感染力和安全性;应用含有人HSP70基因的重组腺病毒(Ad.HSP70)进行体外感染,采用ELISA法、Western印迹法及免疫组化染色法检测HSP70基因在心肌细胞中的表达情况。结果:Ad.EGFP感染心肌细胞的效率高于90%,在MOI值为200时,未见心肌细胞的生长明显受抑;ELISA法、Western印迹法以及免疫组化染色法证实转染的心肌细胞在正常生理状态下,可高水平表达HSP70。结论:重组腺病毒Ad.HSP70能够在体外高效、安全地感染心肌细胞,并成功地表达HSP70。     

腺病毒介导的HSP70基因转染对乳鼠心肌细胞缺氧/复氧损伤的保护作用

目的:研究热休克蛋白70(HSP70)基因转染对体外培养的乳鼠心肌细胞缺氧/复氧损伤的保护作用。方法:体外原代培养乳鼠心肌细胞,以携带增强型绿色荧光蛋白(EGFP)基因的腺病毒载体(Ad.EGFP)按不同感染倍数(MOI)感染体外心肌细胞,通过荧光显微镜、流式细胞仪观察所构建腺病毒的感染力和安全性;应用含有人HSP70基因的重组腺病毒(Ad.HSP70)进行体外感染,采用ELISA法、Western印迹法及免疫组化染色法检测HSP70基因在心肌细胞中的表达情况。利用体外心肌细胞缺氧/复氧损伤模型,研究HSP70基因转染对心肌细胞的保护作用。结果:原代培养获得高纯度的乳鼠心肌细胞,随着MOI值升高,Ad.EGFP的感染效率和基因表达增强,在MOI值为50时,Ad.EGFP感染心肌细胞的效率高于90%,在MOI值为200时,未见心肌细胞的生长明显受抑;ELISA法、Western印迹法证实转染的心肌细胞在正常生理状态下,可高水平表达HSP70。免疫组化染色法结果显示,表达的HSP70主要分布于心肌细胞的胞质和胞核中;利用体外的缺氧/复氧损伤模拟在体的缺血/再灌注损伤,结果显示Ad.HSP70感染组的细胞活力、MT...     

七氟醚和缺氧预适应诱导乳鼠心肌细胞HSP70表达的改变

目的 :探讨七氟醚预适应和缺氧预适应对乳鼠心肌细胞热休克蛋白 70表达的影响。方法 :第 2代培养心肌细胞随机分为正常对照组 (C组 )、缺氧 /复氧组 (A/R组 )、缺氧预适应组 (IP组 )和七氟醚预适应组 (S组 ) ,每组均缺氧 2h ,复氧 48h。分别取复氧 0 ,1,12 ,2 4,36和 48h的细胞 ,用免疫组化染色检测HSP70 表达并进行图象分析。结果 :在各个时间点 ,S组和IP组间的HSP70 表达均显著高于A/R组和C组 (P <0 .0 1) ,A/R组的HSP70 表达略高于C组 ,S组和IP组间的HSP70 表达差异无显著性 (P >0 .0 5 )。随着复氧时间的延长 ,S组和IP组间的HSP70 表达从 1h开始增加 ,2 4h表达最强 ,与 1h相比差异具有显著性 (P <0 .0 5 )。结论 :七氟醚预处理和缺氧预处理均可诱导乳鼠心肌细胞HSP70 在延迟相呈高表达 ,提示HSP70 参与了七氟醚预适应和缺氧预适应的延迟保护相。     

七氟醚和缺氧预适应诱导乳鼠心肌细胞HSP—70表达的改变

目的：探讨七氟醚预适应和缺氧预适应对乳鼠心肌细胞热休克蛋白70表达的影响。方法：第2代培养心肌细胞随机分为正常对照组(C组)、缺氧/复氧组(A／R组)、缺氧预适应组(IP组)和七氟醚预适应组(S组)，每组均缺氧2h，复氧48h。分别取复氧0，1，12，24，36和48h的细胞，用免疫组化染色检测HSP70表达并进行图象分析。结果：在各个时间点，S组和IP组间的HSP70表达均显著高于A／R组和C组(P＜0．01)，A／R组的HSP70表达略高于C组，S组和IP组间的HSP70表达差异无显著性(P＞0．05)。随着复氧时间的延长，S组和IP组间的HSP70表达从1h开始增加，24h表达最强，与1h相比差异具有显著性(P＜0．05)。结论：七氟醚预处理和缺氧预处理均可诱导乳鼠心肌细胞HSP70在延迟相呈高表达，提示HSP70参与了七氟醚预适应和缺氧预适应的延迟保护相。     

单核细胞Toll样受体4可能介导热休克蛋白70信号的转导

目的寻找Toll样受体4(TLR4)新的配体,探讨热休克蛋白70(HSP70)与TLR4的相互关系。方法收集人单核细胞体外培养,加入终浓度5．0μg／ml HSP70,分别于加入后0、30、60、120min中止刺激,免疫组化检测核因子-κB(NF—κB);加入不同浓度TLR4阻断剂孵育后,予HSP70刺激,120min后检测NF—κB。用流式细胞术检测HSP70刺激后单核细胞膜TLR4受体数目的变化。同时用ELISA法检测加不同浓度TLR4阻断剂后上清液肿瘤坏死因子-α(TNF—α)的浓度。结果HSP70可刺激单核细胞NF—κB核移位,TLR4阻断剂可阻断HSP70这一效应。HSP70的刺激可导致单核细胞膜TLR4受体数目显著下调。HSP70刺激单核细胞引起上清液TNF—α浓度增加,加入TLR4阻断剂可显著降低TNF—α浓度。结论HSP70可通过细胞膜TLR4转导信号,是TLR4的内源性配体。     

The regulatory effect of memantine on expression and synthesis of heat shock protein 70 gene in neonatal rat models with cerebral hypoxic ischemia

Objective To evaluate the neuroprotective effect of memantine, a non-competitive antagonist at the N-methyI-D-aspartate receptor, against hypoxic ischemia (HI) by exploring its regulation on the expression and synthesis of heat shock protein 70 (HSP70) gene in neonatal rat models with cerebralHI.Methods Memantine was intraperitoneally injected at a dose of 20 mg/kg in neonatal rat models either before (PRE group) or after (POST group) induction of HI. The expression and synthesis of the HSFr70 gene and its corresponding product were determined by rapid competitive PCR and immunohistochemistry, respectively.Results There was an increase in the expression of HSP70 mRNA two hours after induction of HI,which reached its peak at 48 hours, then decreased gradually. The same expression occurred at relatively low levels in the control group. Also, HSP70 synthesis was detected as early as 2h after HI,reached its peak between 48 and 72 hours, then declined over time. After memantine administration,the expression of the gene and its synthesis of the corresponding product decreased significantly during the time intervals 24 -72 h for the gene and 48 -72 h for the product compared to the HI group.Conclusion It was shown that HI is very sensitive to the expression of the HSP70 gene and synthesis of its corresponding product, which could be regulated by memantine. The latter may have the ability to reduce brain damage; thus decreased HSP70 mRNA expression could be a marker for HI. It is suggested that memantine can be a promising agent for neuroprotection against HI, although an overall and objective assessment of memantine is required to see if it can be used on neonates clinically later on.     

去甲肾上腺素诱导热休克蛋白70保护心肌细胞的机制

目的探讨去甲肾上腺素预处理心肌细胞后诱导心肌热休克蛋白70(HSP70)的表达及其对心肌细胞保护作用机制。方法 Wistar大鼠乳鼠心肌细胞培养,分为3组:对照组:心肌培养3～5天未施加任何因素;缺氧/复氧组:心肌细胞培养3～5天后,模拟缺氧(加入饱和氮气pH 6.8 D-Hank’s液培养细胞)3 h,复氧(用含20%新生牛血清的DMEM液培养细胞)孵育6 h;去甲肾+缺氧/复氧组:模拟缺氧前30 min加入100 nmol/L去甲肾,其它同缺氧/复氧组。测定心肌HSP70和bcl-2以及相关的细胞凋亡指标。结果 HSP70和bcl-2的表达在去甲肾+缺氧/复氧组明显高于缺氧/复氧组,去甲肾+缺氧/复氧组的细胞凋亡率明显低于缺氧/复氧组。结论去甲肾上腺素预处理可能通过诱导心肌组织HSP70和bcl-2高表达,发挥其对供心的保护作用。     

热休克蛋白质70对大鼠肝脏缺血再灌注后NOS活力的影响

目的为探讨热应激预处理对肝脏缺血再灌注损伤的保护作用的机制,采用局部热应激处理诱导热休克蛋白质(HSP70)的表达,检测了HSP70对肝脏缺血再灌注时NOS活力的影响。方法将实验大鼠随机分为热应激预处理组与非预处理组,对比观察两组动物肝脏缺血再灌注后0、4、8、12、24h期间内肝脏HSP70的表达、NOS活力及血清乳酸脱氢酶(lactate dehydrogenase,LDH)的活性与肝脏组织学改变。结果热应激预处理组HSP70的表达水平均比非预处理组同一时间点高,而NOS活力及血清LDH的活性较非预处理组低。与非预处理组比较,经热应激预处理肝组织损伤较轻。结论热应激预处理诱导产生的热休克蛋白70保护肝脏缺血再灌注损伤的作用途径之一可能是通过抑制NO的产生,从而降低大量自由基对肝脏的损害。     

重组腺病毒介导的HSP70转染对肠上皮细胞缺氧再复氧损伤的防护作用

目的　研究重组腺病毒介导的热休克蛋白 70转染对肠上皮细胞缺氧再复氧损伤的保护作用。方法　将重组含人全长HSP70基因的腺病毒载体 (AdCMVHSP70 )转染体外培养的肠上皮细胞株IEC 6 ,检测转染细胞HSP70的基因表达水平。对照组 (转染空载体组 )、转染HSP70 2 4h、48h及72h组IEC 6细胞经缺氧再复氧处理后 ,分别对细胞的活力、凋亡及死亡水平进行检测分析。结果AdCMVHSP 70转染组细胞HSP70基因表达为阳性 ,对照组无表达。经缺氧再复氧处理后 ,AdCMVHSP70转染组细胞活力较对照组明显增强 (P <0 0 1 ) ,Annexin V Flous试剂盒检测死亡细胞明显减少 (P<0 0 1 ) ,凋亡有一定水平的抑制 (P <0 0 5)。结论　重组腺病毒介导的HSP70转染可保护肠上皮细胞抵抗缺氧再复氧损伤 ,具有明确的细胞保护作用。而其具体保护机制可能与抑制细胞凋亡有关