Glutamine supplementation attenuates intestinal apoptosis by inducing heat shock protein 70 in heatstroke rats

BACKGROUND:Heatstroke is the most hazardous heat-related illness and has a high fatality rate.We investigated whether glutamine supplementation could have a protective effect on heatstroke rats.METHODS:Twenty-five 12-week-old male Wistar rats(weight 305±16 g)were randomly divided into a control group(n=5),heatstroke(HS)group(n=10),and heatstroke+glutamine(HSG)group(n=10).Seven days before heat exposure,glutamine(0.4 g/[kg·d])was administered to the rats in the HSG group by gavage every day.Three hours after heat exposure,serum samples were collected to detect white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines in the rats.The small intestine tissue was stained to analyze pathological structural changes and apoptosis.Finally,immunohistochemistry and Western blotting were used to analyze the expression levels of heat shock protein 70(HSP70).Multiple comparisons were analyzed by using one-way analysis of variance,and the Bonferroni test was conducted for the post hoc comparisons.RESULTS:After heat exposure,the core temperature of the HS group(40.65±0.31°C)was higher than the criterion of heatstroke,whereas the core temperature of the HSG group(39.45±0.14°C)was lower than the criterion.Glutamine supplementation restored the increased white blood cells,coagulation indicators,blood biochemical indicators,and inflammatory cytokines that were induced by heatstroke to normal levels.The intestinal mucosa was injured,and the structure of tight junctions was damaged in the HS group;however,the structure of intestinal mucosal epithelial cells was stable in the HSG group.Glutamine supplementation alleviated intestinal apoptosis and up-regulated HSP70 expression.CONCLUSION:Glutamine supplementation may alleviate intestinal apoptosis by inducing the expression of HSP70 and have a protective effect on heatstroke rats.

Influence of Tanshinone lla on heat shock protein 70,Bcl-2 and Bax expression in rats with spinal ischemia/reperfusion injury

Tanshinone lla is an effective monomer component of Danshen, which is a traditional Chinese medicine for activating blood circulation to dissipate blood stasis. Tanshinone Ila can effectively improve brain tissue ischemia/hypoxia injury. The present study established a rat model of spinal cord ischemia/reperfusion injury and intraperitoneally injected Tanshinone lla, 0.5 hour prior to model establishment. Results showed that Tanshinone Ila promoted heat shock protein 70 and Bcl-2 protein expression, but inhibited Bax protein expression in the injured spinal cord after ischemia/reperfusion injury. Furthermore, Nissl staining indicated a reduction in nerve cell apoptosis and fewer pathological lesions in the presence of Tanshinone Ila, compared with positive control Danshen injection.

Radiofrequency ablation,heat shock protein 70 and potential anti-tumor immunity in hepatic and pancreatic cancers:a minireview

BACKGROUND: Radiofrequency ablation (RFA) is a minimally invasive surgical procedure which has widespread popularity in the treatment of hepatic and pancreatic cancers. Increased evidence indicates that RFA stimulates anti-tumor immunity, possibly through the induction heat shock protein 70 (HSP70) expression. HSP70 has the capacity to affect the immunogenicity of tumor cells, to chaperone antigenic peptides and deliver these into antigen presentation pathways within antigen-presenting cells, and to activate and regulate innate and adaptive immunity, which makes it useful in immunotherapeutic strategies for the treatment of cancers. DATA SOURCES: An English-language literature search was conducted using MEDLINE (1991-2010) on anti-tumor immunity, heat shock protein 70, radiofrequency ablation, hepatic cancer, pancreatic cancer, and other related subjects. RESULTS: RFA has an increasing application in the surgical treatment of hepatic and pancreatic cancers. Increased evidence indicates that RFA can induce the expression of HSP70 which possesses properties that enable it to influence a variety of immunological processes. Tumor-derived HSP70 is regarded as a potent adjuvant facilitating presentation of tumor antigens and induction of anti-tumor immunity. CONCLUSIONS: This review addresses the potential association of RFA, HSP70, and anti-tumor immunity in treatment of hepatic and pancreatic cancers. To establish direct evidence of a potential association of RFA, HSP70, and anti-tumor immunity in hepatic and pancreatic cancers, further investigations should be conducted.

Association of high expression in rat gastric mucosal heat shock protein 70 induced by moxibustion pretreatment with protection against stress injury

AIM:To study the effect of moxibustion on Zusanli or Liangmeng point on gastric mucosa injury in stress-induced ulcer rats and its correlation with the expression of heat shock protein 70 (HSP70). METHODS:Sixty healthy SD rats (30 males,30 females) were divided into control group,injury model group,Zushanli point group,Liangmeng point group. Stress gastric ulcer model was induced by binding cold stress method. Gastric mucosa ulcer injury (UI) index was calculated by Guth method. Gastric mucosa blood flow (GMBF) was recorded with a biological signal analyzer. Protein content and gene expression in gastric mucosal HSP70 were detected by immunohistochemistry (IHC) and reverse transcription polymerase chain reaction (RT-PCR). Thiobarbital method was used to determine malondialdehyde (MDA) content. Gastric mucosal endothelin (ET) and prostaglandin E2 (PGE2) were analyzed by radioimmunoassay. RESULTS:High gastric mucosal UI index,high HSP70 expression,low GMBF and PGF2,elevated MDA and ET were observed in gastric mucosa of rats subjected to cold stress. Moxibustion on Zusanli or Liangmeng point decreased rat gastric mucosal UI index,MDA and ET. Conversely,the expression of HSP70,GMBF,and PGE2 was elevated in gastric mucosa after pretreatment with moxibustion on Zusanli or Liangmeng point. The observed parameters were significantly different between Zusanli and Liangmeng points. CONCLUSION:Pretreatment with moxibustion on Zusanli or Liangmeng point protects gastric mucosa against stress injury. This protection is associated with the higher expression of HSP70 mRNA and protein,leading to release of PGE2 and inhibition of MDA and ET,impairment of gastric mucosal index.

Expression of Heat Shock Protein 70 and 27 in Non-small Cell Lung Cancer and Its Clinical Significance

The heat shock proteins （HSPs） 70 and HSP 27 expression in patients with non-small cell lung cancer （NSCLC） was studied and the relation.ship between HSP 70 and HSP 27 with the clinicopathological features of NSCLC was investigated. The expression of HSP 70 and HSP 27 was detected in tumor tissues from 60 patients with NSCLC by S-P immunohistochemistry. The findings were analyzed in combination with the histological types, histopathological differentiation, lymph node metastasis, patients＇ clinical stages, smoking history and gender. The results showed that of the 60 NSCLC tissue specimens studied, the immunoreactivity of HSP 70 and HSP 27 was detected in 47 （78.3 %） and 43 （71.7 %） specimens, respectively. A positive correlation was found between the overexpression of HSP 70 and HSP 27. The histopathological differentiation, lymph node metastasis, clinical stages and smoking history were correlated to the expression of HSP 70, but not to the expression of HSP 27. No statistical significance was observed in histological types and gender with respect to both HSP 70 and HSP 27 expression. It is suggested that the HSP 70 expression is a powerful and significant prognostic indicator and is related to histopathological differentiation, lymph node metastasis, patients＇ clinical stages, smoking history, whereas HSP 27 expression is not.

Heat Shock Protein 70 Gene Polymorphisms in Han Nationality of China with Chronic Obstructive Pulmonary Diseases

In order to investigate whether polymorphism in gene for heat shock protein 70 (HSP70) has any bearing on individual susceptibility to the development of chronic obstructive pulmonary disease(COPD), the geotypes of 88 patients with COPD and 87 healthy smoking control subjects were tested by polymerase chain reaction followed by restriction fragment polymorphism analysis for HSP70 gene. In COPD group, HSP70 1 genotype A/A, A/B and B/B was 59.1 %, 35.2 % and 5.7 %, HSP70 2 genotype A/A, A/B and B/B was 26.1 %, 54.6 % and 19.3 %, and HSP70 hom genotype A/A, A/B and B/B was 70.4 %, 27.3 % and 2.3 % respectively. In the control group, it was 60.9 %, 27.5 % and 3.5 %, 20.7 %, 56.3 % and 23.0 %, and 54.0 %, 42.5 % and 3.5 %, respectively. The frequency of polymorphic genetypes showed no difference between the COPD group and the control group ( P >0.05). It was suggested that geneic polymorphism in HSP70 is not associated with development of COPD in Han nationality of China.

Neuroprotective effect of heat shock protein 70 Inhibition of Tau protein expression

BACKGROUND： Previous studies have shown that heat shock protein 70 （HSP70） has neuroprotective effects by decreasing phosphorylation of Tau protein, thereby reducing the expression of Tau protein and proper aggregation. OBJECTIVE： To observe and verify expressional changes of HSP70 and Tau in retinal ganglion cells following stretch injury to the right optic nerve in rats, and to determine the effect of heat stress pretreatment on HSP70 and Tau protein expressions. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Laboratory of Neurology Research Institute of the First Affiliated Hospital of Chongqing Medical University from March to June 2006. MATERIALS： Instant SABC immunohistochemistry kit, as well as mouse anti-HSP70 and rabbit anti-Tau polyclonal antibodies, were purchased from Wuhan Boster Bioengineering Limited, China. METHODS： A total of 57 male, Wistar rats were randomly assigned to 4 groups： control （n = 3）; 150-180 g stretch force was induced in the right optic nerves in stretch-only group （n = 18） to establish optic nerve stretch injury model; heat stress was applied to 18 animals in heat-stress treatment group; 18 rats in the heat-stress pretreatment plus stretch group were subjected to identical stretch injury as stretch-only group after 24-hour heat-stress pretreatment. According to sacrifice time, the groups were assigned to 6 subgroups at different time points of 4, 8, and 16 hours, and 1,3, and 5 days, with 3 rats in each subgroup. No treatment was performed in the control group except anesthesia. MAIN OUTCOME MEASURES： Morphological changes of optic nerves and retinal ganglion cells following stretch injury were observed by light microscopy following hematoxylin-eosin staining. HSP70 and Tau protein expression levels were observed in retinal ganglial cells from each group using im munohistochemistry. RESULTS： （1） Compared with the control group, morphological axonal and retinal ganglial cell changes, as well as a decreased number of retinal ganglial cells, were identified in the stretch-only group （P 〈 0.01）. Pathological damage in optical nerve and retinal ganglial cells were not remarkable in the heat-stress pretreatment plus stretch group, with no statistical difference in the number of retinal ganglial cells compared with the control group （P 〉 0.05）. （2） Compared with the control group significantly increased HSP70 expression in retinal ganglial cells occurred in the stretch-only, heat-stress treatment, and heat-stress pretreatment plus stretch groups （P 〈 0.05 or P 〈 0.01 ）. The peak of HSP70 expression was earlier in the heat-stress pretreatment plus stretch group compared with the stretch-only and heat-stress treatment groups, and was expressed over a longer period of time compared with the heat-stress treatment group. Compared with the control group, Tau expression in the retinal ganglial cells rapidly increased 4-16 hours following stretch injury in the stretch-only group （P 〈 0.05 or P 〈 0.01）, and obviously decreased in the heat-stress pretreatment plus stretch group （P 〈 0.05 or P 〈 0.01 ）. CONCLUSION： Tau expression increased following stretch injury, with an earlier expression peak than HSP70, which indicated that stretch injury-induced HSP70 expression was not strong or quick enough to sufficiently protect the nerve. A much more enhanced HSP70 expression, with an earlier peak and longer expression period, was observed in rats subjected to stretch injury following heat stress, which demonstrated that HSP70 exhibited neuroprotective functions by reducing abnormal aggregation of Tau.

Genotoxicity and Reduced Heat Shock Protein 70 in Human Airway Smooth Muscle Cells Exposed to Cigarette Smoke Extract

Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease （COPD）. The purpose of this study was to investigate genotoxicity and heat shock protein 70 （Hsp70） in human airway smooth muscle cells （HASMCs） exposed to cigarette smoke extract （CSE）. HASMCs was exposed to CSE with different doses for 24 h. The level of 8-hydroxydeoxyguanosine （8-OHdG） was determined by using HPLC-ECD, the DNA damage was ana- lyzed by using comet assay, and apoptosis was examined by using Annexin-FITC/PI staining. The pro- duction of Hsp70 after CSE stimulation was tested. Results indicated that CSE significantly increased the level of 8-OHdG, DNA damage and cell apoptosis, and reduced the production of Hsp70. In par- ticular, levels of Hsp70 were inversely correlated with 8-OHdG, DNA damage and cell apoptosis. It was concluded that cigarette smoke induced genotoxicity and decreased the production of cell protective protein Hsp70, which may contribute to the development of some airway diseases.

Novel heat shock protein Hsp70L1 activates dendritic cells and acts as a Th1 polarizing adjuvant

Heat shock proteins (HSPs) are reported to act as effective adjuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), and the chemokines IP-10, macrophage inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and normal T cell expressed and secreted (RANTES). The induction of interferon-gamma-inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)(257-264) induces an OVA(257-264)-specific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E.G7-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases.

Effect of heat shock protein 70 on cerebral ischemia

OBJECTIVE： TO summarize the relationship between heat shock protein 70 （HSP70） and cerebra ischemia. DATA SOURCES： An online search of Medline database was undertaken to identify relevant articles published in English from January 1980 to December 2005 by using the keywords of ＂heat shock protein 70, ischemia＂. Meanwhile, Chinese relevant articles published from January 2000 to December 2005 were searched in China National Knowledge Infrastructure （CNKI） database and Chinese Journal of Clinical Rehabilitation with the keywords of ＂heat shock protein 70, cerebral ischemia＂ in Chinese. STUDY SELECTION ： More than 100 related articles were screened, and 29 references mainly about HSP70 and cerebral ischemia were selected, including basic and clinical researches. As to the articles with similar content, those published in the authoritative journals in recent 3 years were preferential. DATA EXTRACTION： A total of 29 articles were collected and classified according to the structure, function and clinical application of HSP70. Among them, 1 article is about the structure of HSP70, 27 about the relationship between HSP70 and cerebral ischemia, and 2 about the clinical application of HSP70. DATA SYNTHESIS： HSP70 is one of the most conservative proteins during biological evolution. Experiments in cerebral ischemia revealed that HSP70 expression was time-dependent, also correlated with the injured site and severity. The cerebral ischemia induced HSP70 gene expression in hippocampus of gerbil had protection to tolerance of fatal ischemic injury for neurons. The increase of HSP70 expression may be one of the endogenous protective mechanisms during cerebral ischemia, and can effectively alleviate cerebral ischemia. Thus HSP70 protein and HSP70 mRNA have been taken as important indexes extensively applied in the basic study of cerebral ischemia by some scholars abroad. CONCLUSION： HSP70 plays a protective role in cerebral ischemia, and a deeper research into the biological function of HSP70 will provide a new way for the therapy of cerebral ischemia.

Enhancing the treatment effects of tumor cell purified autogenous heat shock protein 70-peptide complexes on HER-3-overexpressing breast cancer

Objective The aim of this study was to enhance the treatment effect of tumor purified autogenous heat shock protein 70-peptide complexes(HSP70-PCs)on HER-3-overexpressing breast cancer.Methods In this study,we first studied the expression of HER-3 in breast cancer tissues and its relationship with patient characteristics.We then purified HSP70-PCs from primary breast cancer cells with different HER-2 and HER-3 expression profiles and determined the cytotoxicity of autogenous dendritic cells(DCs)and CD8+T cells induced by these complexes.Third,recombinant human HSP70-HER-3 protein complexes were used to inhibit the autogenous HSP70-PCs purified from HER-3-overexpressing breast cancer cells,and the resulting immunological response was examined.Results The results show that HSP70-PCs can be combined with recombinant HSP70-HER-3 protein complexes to induce stronger immunological responses than autogenous HSP70-PCs alone and that these treatments induce autogenous CD8+T cell killing of HER-3-positive breast cancer cells.Conclusion These findings provide a new direction for HSP70-DC-based immunotherapy for patients with HER-3-overexpressing breast cancer.

The diagnostic role of heat shock protein 70 in acute rejection after pancreatioduodenal transplantation in rats

Objective To explore the diagnositc role of heat shock protein ( HSP) 70 in acute rejection after pancreatioduodenal transplantation in rats. Methods Groups of Wistar rats underwent total pancreatioduodenal transplantation from allogeneic SD or syngeneic Wistar rats. The grafts were harvested on the posttransplantation day 3,5 and 7 and were used to detect the expression of HSP70 by immunohistochemistry and Western Blotting quantitative methods. The correlation between HSP70 expression and pathological findings was observed. Results The level of HSP70 in the isografts did not change greatly( P 】 0.05); the level of HSP70 in the allografts was increased progressively on the posttransplantation day3, 5 and 7 ( P 【 0.01). There was a significant correlation between HSP70 and pathological score in the allograft group (P 【 0.01, r = 0.934). Conclusion HSP70 involved in pancreas allograft rejection and could be useful for early diagnosis of acute rejection following pancreas transplantation. 8 refs,2 tabs.

Effect of Ultraviolet Radiation on Hsp70 Protein Expression in HaCaT Cells

Ultraviolet radiation by its wavelength is divided into: UVA, UVB and UVC. Only UVA and UVB manage to penetrate the ozone layer, but due to anthropological activities, all of them are capable of interacting with humans to a greater or lesser extent, and can generate adverse effects such as cellular stress when interacting with intra-and extracellular biomolecules. The skin is the first organ in contact with UV radiation, and the stress it generates can be analyzed by the expression of a bioindicator of cellular damage such as Hsp70. Therefore, the objective of the project was: to determine the effect of UVA, UVB and UVC radiation on HaCaT epithelial cells, by analyzing the expression of Hsp70. Materials and methods: HaCaT cells were cultured in vitro, which were irradiated with UVA, UVB and UVC light at different doses, to subsequently determine the degree of Hsp70 expression by Immunodetection by PAGE-SDS and Western Blot. Results: Basal expression of Hsp70 was observed in no irradiated HaCaT cells. When HaCaT cells were irradiated with UVA, UVB, UVC, an increase in this Hsp70 protein was observed. With UVA, a higher degree of expression was observed at a time of 30 minutes of irradiation. With UVB the highest expression shifted to a time of 20 minutes. With UVC, overexpression was observed after 10 minutes. Conclusion: UV radiation generates cellular stress on HaCaT cells, evaluated by the stress bioindicator Hsp70. According to the wavelength of UV radiation, those that have a shorter wavelength have a greater potential for cellular damage, such as UVC.

Melatonin protects mouse oocyte from heat stress damage

Objective:To explore the potential effect of melatonin on the in-vitro maturation of mouse oocytes under heat shock condition.Methods:This study used a heat shock model of mouse oocyte maturation.The oocytes were randomly divided into three groups:control group,heat shock group and heat shock+melatonin group,in order to evaluate the effect of 1×10^(−9) mol/L melatonin on the quality of oocytes after heat shock.Results:In comparison with the control group,the maturation rate of mouse oocytes in heat shock group was significantly decreased[(33.00±0.07)%vs.(85.00±0.03)%,p<0.01],with abnormal spindle assembly,and the early apoptosis rate was significantly increased[(59.7±4.5)%vs.(22.0±3.5)%,p<0.01].Compared with heat shock group,the maturation rate of oocytes was significantly increased in heat shock+melatonin group[(70.00±0.05)%vs.(33.00±0.07)%,p<0.01],meanwhile,the spindle abnormality rate and the early apoptosis rate were significantly decreased accordingly[(37.3±6.1)%vs.(59.7±4.5)%,p<0.01].The expression level of heat shock protein 70 was significantly up-regulated in heat shock+melatonin group in comparison with other two groups(p<0.01).Conclusions:By regulating the over-expression of heat shock protein 70,melatonin can improve the declined maturation rate of oocytes and the increased rates of spindle assembly abnormality and early apoptosis caused by heat shock.

血清HSP70、VEGF联合检测对可切除胰腺癌诊断及术后生存预测价值

目的探讨血清热休克蛋白70(heat shock protein 70,HSP70)、血管内皮生长因子(vascular endothelial growth factor,VEGF)联合检测对可切除胰腺癌诊断及术后生存预测价值。方法选取2015年12月至2018年10月南方医科大学附属萍乡医院124例行手术治疗的Ⅰ~Ⅲ期原发性胰腺癌患者作为胰腺癌组,另选取16例同期于本院进行健康体检者作为对照组,检测胰腺癌组患者手术前和手术后以及对照组血清HSP70、VEGF水平,分析两项指标相关性,研究其与临床病理及预后的关系。结果血清HSP70、VEGF含量:术前>术后7d>术后1个月>对照组(P<0.05),胰腺癌组患者术前、术后7d、术后1个月血清HSP70水平与血清VEGF含量呈正相关(P<0.05)。胰腺癌组患者术前肿瘤>3cm、肿瘤分化程度低、临床分期Ⅲ期、淋巴结转移患者血清HSP70、VEGF含量分别高于肿瘤≤3cm、肿瘤分化程度高、临床分期Ⅰ期或Ⅱ期、未发生淋巴结转移者(P<0.05)。血清HSP70和VEGF对胰腺癌的诊断均有较好的特异性,联合诊断效果更好(P<0.05)。HSP70浓度和VEGF浓度均与胰腺癌患者术后生存时间呈负相关(P<0.05)。单因素回归分析和多因素Cox回归分析显示肿瘤直径、淋巴结转移、肿瘤淋巴结转移(tumor-node-metastasis,TNM)分期、分化程度、远处转移、HSP70和VEGF浓度均是胰腺癌预后的独立危险因素(P<0.05)。结论胰腺癌患者血清HSP70和VEGF与恶性生物学行为呈正相关,与生存时间呈负相关,是胰腺癌术后预后的独立危险因素。

肉鸡热应激病理损伤与应激蛋白(HSP_(70))相关性研究

通过血液临床病理学、组织学和免疫组织化学检测技术,对AA肉鸡进行了为期10 h的急性热应激,观察分析了高热应激状态下受试鸡组织损伤及其与HSP70的相关性。热应激受试鸡组织脏器在应激初期即开始出现较明显的组织病理学改变,表现为心肌纤维、肾小管上皮细胞等呈现不同程度的变性、坏死等退行性变化;外周血液中反映受试鸡心肌等细胞组织损伤的肌酸激酶(对照)活性显著升高;反映鸡体基础代谢水平的甲状腺素T3和T4、胰岛素则呈现不同程度的下降趋势。应激持续较长时间(10 h)后受试鸡外周血液中对照含量下降的幅度明显趋缓的现象可能与持续应激状态下心肌纤维内产生大量HSP70而产生保护性反应有关,HSP70在各组织脏器血管壁上的强阳性分布提示HSP70与血管功能密切相关。

妊娠早期小鼠子宫内膜热休克蛋白70的免疫组化研究

目的 :研究妊娠早期小鼠子宫内膜热休克蛋白 70的表达。方法 :采用免疫组织化学方法。结果 :热休克蛋白 70主要存在于子宫内膜固有层的基质细胞及蜕膜细胞 ,内膜上皮、腺上皮中未见表达。与未孕小鼠相比 ,孕鼠热休克蛋白 70免疫反应阳性细胞显著增多 (P <0 .0 1 )且随妊娠日龄的增加而增加 (P <0 .0 1 )。结论 :热休克蛋白70可能参与了子宫内膜蜕膜反应中基质细胞的增殖 。

丹酚酸B预适应对缺氧复氧损伤细胞热休克蛋白70mRNA表达的影响

[目的 ]探讨丹酚酸B(SalB)预适应的细胞保护机制是否与诱导热休克蛋白 70 (HSP70 )合成有关。[方法 ]在缺氧复氧损伤大鼠心脏微血管内皮细胞 (CMEC)后 ,采用RT -PCR法观察SalB预适应对细胞HSP70mR NA表达的影响。 [结果 ]HSP70mRNA在正常的CMEC有较低表达 ,缺氧刺激使其表达明显增强。SalB预适应促进HSP70mRNA表达增强 ,作用明显优于缺氧预适应 (HPC)。晚期预适应保护中 ,SalB预适应同样促使HSP70mRNA表达明显增强 ,与HPC具有增强表达的叠加效应。 [结论 ]SalB预适应通过诱导HSP70表达升高发挥细胞保护作用。

热休克反应中小鼠心脏HSP70表达的免疫组织化学研究

用免疫组织化学方法研究了小鼠心脏在不同温度 ( 40、4 2、4 4、4 6℃ )热休克处理后 ,各恢复期 ( 2、4、8、1 2、2 4小时 )HSP70的表达。结果表明 ,( 1 ) 4 4、4 6℃热处理能诱导心肌细胞合成HSP70 ,以 4 6℃为多 (P<0 0 1 ) ,且于恢复期 4～ 8小时为合成高峰 (P <0 0 1 ) ;( 2 )阳性免疫反应定位于心肌细胞质中 ,核呈阴性反应。提示了心脏有较强的耐热能力。

一氧化氮供体预处理对乳鼠心肌细胞的延迟保护作用及其机制

目的 探讨一氧化氮模拟预处理延迟保护作用的机制。方法 体外培养新生大鼠心肌细胞 ,实验分为 :①阴性对照组 (Normal组 ) ;②SNAP组 :一氧化氮 (nitricoxide ,NO)供体S 亚硝基 N 乙酰青霉胺 (S nitroso N acetyl 1 ,1 penicil lamine ,SNAP ,5 0 0 μmol·L-1 )与心肌细胞共育 2 4h ;③Che +SNAP组 :蛋白激酶C拮抗剂白屈菜季铵碱 (chelerythrinechlo ride ,Che ,1 0 μmol·L-1 )处理心肌细胞 30min后 ,加入SNAP与心肌细胞共育 2 4h ;④PDTC +SNAP组 :核因子κB(NF κB)特异性阻断剂PDTC(1 0 0 μmol·L-1 )处理心肌细胞 30min后 ,加入SNAP与心肌细胞共育 2 4h ;⑤缺氧复氧损伤组 (H/R组 ) :心肌细胞缺氧 6h ,复氧 3h。②～④组部分取细胞爬片以免疫组织化学法观察SNAP对热休克蛋白 70 (HSP70 )表达的影响 ;其余细胞经历H/R损伤后 ,检测心肌细胞存活率及乳酸脱氢酶 (LDH)活性。结果 在正常心肌细胞免疫组织化学法未检测到HSP70的表达 ,心肌细胞经过H/R损伤后 ,可检测到少量HSP70阳性细胞 ,其阳性染色A值为 94 6± 9 1 ,心肌细胞培养上清LDH活性为 (2 1 90 5± 1 5 1 7)U·L-1 ,细胞存活率为 5 1 7%± 4 6 % ,细胞损伤较正常组加重 (P <0 0 1 ) ;SNAP处理细胞后 2 4h ,HSP70阳性细胞数增多 ,