热休克时通过神经酰胺代谢产物激活NIH3T3 细胞ERK的信号通路

热休克可以激活ERK，但信号传导的级联通路仍不清楚。我们的结果提示，在NIH3T3细胞中，热休克引起ERK活性升高是通过神经酰胺的代谢产生鞘氨醇，并伴随着Raf-1蛋白激酶的激活。但是，热休克和神经酰胺不能引起HL-60U937和K562骨髓白血病细胞中ERK活性的升高，提示在这些细胞中神经酰胺到ERK之间的通路有缺陷。     

热休克反应过程中糖皮质激素受体结合活性的变化

本文以人骨肉瘤细胞系(HOS-8603)为细胞模型,研究了热休克反应过程中糖皮质激素受体(GR)的变化规律。HOS-8603细胞经43℃热休克处理30min后,于37℃恢复2～4小时,热休克蛋白70(hsp70)mRNA的表达明显加强;细胞经42℃预处理1小时后,于37℃恢复5小时,再次接受46℃热休克处理时,细胞存活率较未经预处理的对照组明显提高,获得了热耐受能力。在43℃热休克反应过程中,细胞内GR结合活性     

碱性磷酸酶同工酶表达的基因基础

碱性磷酸酶(ALP)广泛分布于细菌和动植物界,在人体以肝、骨、肾、胎盘和小肠的活性最高,肺和嗜中性白细胞也有活性。ALP主要分布在细胞的质膜,在一些疾病时可释入血中,使血清ALP增高。正常组织表达的ALP同工酶ALP是一种糖蛋白。根据酶学和免疫学性质可将正常组织表达的ALP同工酶分为三类:①肝型ALP,包括肝、骨、肾、肺等的ALP.许多酶学性质是相同的,如对热失活敏感,易受L-同型精氨酸(L-HArg)和左     

低渗刺激对成骨样细胞MG63功能的影响

目的本试验拟通过研究低渗透压的静牵张作用,对成骨样细胞MG63的增殖能力、碱性磷酸酶活性以及[Ca2 ]i的影响,探讨该应力形式下成骨样细胞MG63的力学响应特征。方法采用人成骨肉瘤来源的成骨样细胞MG63作为细胞源进行细胞培养传代。用不同渗透压的低渗透液,对成骨样细胞MG63分别进行2 h、4 h、8h、12 h和24 h持续牵张作用后,用免疫组化法检测ALP表达的情况,用ALP试剂盒检测ALP活性的变化,用钙试剂盒检测[Ca2 ]i含量波动情况。结果成骨样细胞MG63的ALP免疫细胞化学染色为阳性。随着作用时间的延长,成骨样细胞MG63在277 mOsm和240 mOsm低渗透液的持续性膨胀作用下,其细胞的[Ca2 ]i、ALP活性缓慢增高,但240 mOsm组ALP活性始终低于对照组(p<0.01);而细胞在163 mOsm低渗液作用下,8 h时出现[Ca2 ]i急剧升高(11.383±0.111),ALP活性(0.326±0.002)明显高于其对照组(p<0.01)。结论结果提示不同水平的低渗膨胀对MG63的增殖分化、ALP活性以及Ca2 -ATPase都有一定的影响作用,且Ca2 内流与ALP活性之间存在一定的相关性。低渗膨胀法作为一种应力形式有一定的实验意义。     

热休克处理骨髓Sca-1+细胞移植治疗小鼠心肌梗死

背景：近年来的研究发现,干细胞可以直接定向分化为成熟心肌细胞或促进其再生,为心肌梗死治疗提供一种全新的治疗策略,但是细胞移植率低使其向心肌细胞分化和执行心肌修复能力下降。 目的：探讨热休克Sca-1+细胞在小鼠心肌梗死治疗中的作用。 方法：磁珠分选骨髓中Sca-1+细胞,对Sca-1+细胞进行热休克处理3 h。建立心肌梗死小鼠动物模型,将其随机分为2组,分别经尾静脉注入1 mL热休克Sca-1+细胞悬液、1 mL非热休克Sca-1+细胞悬液。移植后检测细胞存活率、小鼠心脏功能恢复情况、心肌细胞凋亡数目、心肌纤维化程度以及左心室HSF、HSP70及miR-34a表达。 结果与结论：①热休克Sca-1+细胞移植组小鼠心脏sry基因表达显著高于非热休克Sca-1+细胞移植组。②热休克Sca-1+细胞移植组小鼠射血分数及左心室短轴缩短率显著高于非热休克Sca-1+细胞移植组,左心室的舒张末期内径以及收缩末期内径显著低于非热休克Sca-1+细胞移植组。③热休克Sca-1+细胞移植组小鼠的心脏纤维化程度及心肌细胞凋亡均显著低于非热休克Sca-1+细胞移植组。④热休克Sca-1+细胞移植组小鼠左心室HSF和HSP70表达明显高于非热休克Sca-1+细胞移植组,miR-34a表达明显低于非热休克Sca-1+细胞移植组。结果表明热休克Sca-1+细胞移植能够减少心肌细胞凋亡和心肌梗死面积,改善心脏功能。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程      

热休克蛋白调控的研究进展

热休克蛋白-肽复合物,在机体杀伤肿瘤细胞中发挥了关键的作用,因而以热休克蛋白肽为基础的肿瘤疫苗成为研究的热点。通过热休克处理、细胞因子共孵育等方法,可促进细胞表达热休克蛋白肽;口服某些化合物也能促进机体细胞热休克蛋白肽的表达。这些方法能促进热休克蛋白肽的表达,便于制备充足的疫苗应用于临床,具有广阔的发展前景。     

热应激诱导兔脑热休克蛋白70的合成研究

探讨热应激与热休克诱导的脑组织不同细胞热休克蛋白７０合成。     

鼠巨细胞病毒感染细胞热休克蛋白70与细胞毒T细胞活性的相关性研究

目的体外研究小鼠巨细胞病毒（murine cytomegalovirus,MCMV）感染细胞热休克蛋白70与细胞毒T细胞（CTL）活性相关性。方法体外培养小鼠胚肺细胞,在加入MCMV后16、24、48、72、120h分别收获细胞,用免疫组织化学方法检测HSP70表达情况;CTL活性检测组：体外培养小鼠胚肺细胞,设以下各组：正常细胞对照组,病毒感染组,病毒感染＋放线菌素组,病毒感染＋槲皮素组,病毒感染＋HSP70抗体组,分别在以上时相选用^51Cr释放试验检测CTL活性。结果MCMV感染诱导小鼠胚肺细胞表达HSP70,与正常细胞对照组比较,各时相HSP70表达强度差异均具有显著性,其中16h始升高,120h表达最强。病毒感染组：CTL活性升高,与其它各组比较,各时相差异均具有显著性意义,自16h始升高,120h达最高;放线菌素组、槲皮素组、HSP70抗体组,CTL活性均无显著性差异,自16h始升高,120h达最高,与正常细胞对照组比较,CTL活性均升高。结论MCMV感染细胞热休克蛋白70与CTL的活性具有一定相关性。     

热休克上调THP-1细胞IL-37表达

目的研究热休克(heat shock,HS)对人单核细胞株THP-1细胞IL-37表达及其对促炎细胞因子产生的影响。方法对THP-1细胞进行42℃热休克处理1 h,然后分别于37℃恢复培养0~6 h,用流式细胞术检测胞内IL-37的表达。对THP-1细胞用热休克处理与脂多糖(lipopolysaccharides,LPS)刺激,分别收集细胞及其培养上清,用流式细胞术检测各组细胞IL-37表达,ELISA检测各组细胞培养上清中促炎细胞因子的水平。结果流式细胞术检测结果显示,经42℃热休克处理后THP-1细胞于37℃分别恢复培养0、2、4、6 h,细胞IL-37的阳性表达率分别比对照组增高21.1、30.6、34.1、15.1倍,每个细胞表达IL-37的平均荧光强度(Mean Fluorescence Intensity,MFI)分别比对照组增高4.6、7.5、8.3、3.7倍。此外,还发现THP-1细胞单独用热休克处理或LPS刺激后,其IL-37表达水平无显著差异,但热休克处理结合LPS刺激的细胞IL-37表达水平则分别显著高于单独用热休克处理或LPS刺激的细胞,其MFI分别比单独用热休克处理或LPS刺激细胞增高2.0、1.9倍。ELISA结果显示,LPS刺激后THP-1细胞产生炎症因子IL-1β、TNF-α、IL-6的水平分别比对照组高2.9、2.1、3.3倍,而热休克处理结合LPS刺激的细胞的IL-1β、TNF-α与IL-6的水平则比仅用LPS刺激的细胞分别降低了75.1%、69.6%、66.4%。结论热休克能上调THP-1细胞IL-37表达,其上调表达可能参与抑制促炎细胞因子的产生。     

热休克蛋白在乳腺癌中的作用

热休克蛋白是细胞受各种应激原刺激后诱导产生的一组应激蛋白,具有维持细胞蛋白稳定、促进细胞生存等功能,在细胞生长、发育、分化、基因转录等方面发挥重要作用.近年来发现热休克蛋白也与肿瘤细胞的发生、发展密切相关.在多种肿瘤组织中发现热休克蛋白存在高表达,尤其在乳腺癌中与患者预后密切相关.本文就热休克蛋白的结构、生物学功能、致癌机理以及与乳腺癌的关系作一概述.     

Selective enhancement of cytochrome p-450 activity in rat hepatocytes by in vitro heat shock

We investigated the effect of heat shock on cytochrome P-450 activity in rat hepatocytes and report a significant, selective, and time-dependent enhancement of cytochrome P-450 activity in heatshocked hepatocytes. Stable long-term cultures of rat hepatocytes were heat shocked (42.5 degrees C) for 1 to 3 h and allowed to recover at 37 degrees C. Cytochrome P-450-dependent ethoxyresorufin O-dealkylase (EROD) and benzyloxyresorufin O-dealkylase (BROD) activities were measured up to 48 h after heat shock treatment. In general, the optimal heat shock exposure time was between 2 and 3 h. BROD activity (induced by sodium phenobarbital) increased approximately 6-fold in hepatocytes heat shocked for 3 h in comparison with hepatocytes maintained at 37 degrees C. EROD activity (induced by 3-methylcholanthrene) increased 2-fold on exposure to heat shock for 2 h. The expression of inducible heat shock proteins Hsp70 and Hsp32 was verified by Western immunoblot analyses. In the absence of the appropriate inducer, heat shock treatment did not enhance cytochrome P-450 activity. Furthermore, enhanced P-450 enzyme activity was delayed for heat-shocked hepatocytes. It is hypothesized that heat shock treatment attenuates the negative effects triggered by the addition of the toxic inducers and possibly stabilizes the levels of cytochrome P-450 proteins. These results suggest that heat shock treatment may be used to enhance the functionality of hepatocytes, specifically, in bioartificial liver assist devices.     

Role of heat shock proteins in the mechanism of cardioprotective effect of transient hyperthermia and delayed preconditioning

This review article focuses on discussing the role of the heat shock proteins (HSP) in myocardial protection against ischemia-reperfusion injury. In the present time, it has also been recognized that HSP may responsible for the increase in cardiac tolerance to ischemia-reperfusion after heat shock or after delayed ischemic preconditioning. The enhancement of the HSP expression in transgenic mice promotes an elevation of cardiac resistance to ischemia-reperfusion. The same effect is induced by transfection of the HSP genes. It has been established that deletion of the HSP70.1 and HSP70.3 genes abolishes a cardioprotective effect of delayed preconditioning. The mechanism by which HSP protect the heart against ischemia-reperfusion remains obscure. It has been proposed that HSP protect the heart via refolding proteins, an increase in 5'-nucleotidase activity, an improvement of Ca(2+)-pump function in sarcoplasmic reticulum during ischemia-reperfusion.     

Infectious stunting and leg weakness in broilers. II. Studies on alkaline phosphatase isoenzymes in blood plasma

Total alkaline phosphatase (ALP) activity in blood plasma of broilers suffering from infectious stunting after artificial infection was constantly higher than that of uninoculated control birds. While total ALP activity in blood plasma from inoculated broilers of various ages decreased after incubation at 56 degrees C, it increased in similarly treated plasma collected from broilers at 3, 21 and 28 days after inoculation. Investigations into the organ origin of the plasma ALP isoenzymes with agarose electrophoresis, column chromatography, L phenylalanine inhibition and heat treatment showed that the main part of ALP activity in blood plasma of both, inoculated and uninoculated birds was most likely of intestinal origin. In 3-day-old broilers no heat sensitive part of total ALP could be measured.     

Isoenzymes of alkaline phosphatase in epileptic patients receiving carbamazepine monotherapy.

The effects of carbamazepine monotherapy were investigated in 20 female and 21 male epileptic patients to determine whether treatment would induce an increase in serum alkaline phosphatase (ALP) activity, a known effect of many anticonvulsant drugs. Serum total ALP activity was increased in nine out of the 41 patients (22%), serum bone ALP activity was increased in 10 (24%), and serum non-bone ALP activity was increased in three (7%). There was no significant difference when the mean of the patients' serum total ALP was compared with that of the controls. Twenty per cent of the patients with increased serum bone ALP had normal serum total ALP, indicating that increased serum bone isoenzyme activity may precede an increase in the total enzyme activity. This should be considered when interpreting results of increased total ALP in epileptic patients.     

Small increases of the serum alkaline phosphatase activity and malignant changes

In order to see the clinico-pathological significance of the small increase of serum alkaline phosphatase (ALP) activity alone in routine laboratory examinations, we picked up 76 new out-patients of adult within the two-fold high ALP level in contrast to the reference range in the Akita University Hospital for one year, and then studied the relation between the histories and serum ALPs of 33 patients whose ALP had increased pathologically or decreased after intervention such as surgical operations. The ratio of the patients with malignant tumors to the tested all patients was 13 to 76 (17%). Immunochemical analysis of sera for the cancers of the lung, larynx and prostate showed that the small amount of the placental isozyme or intestinal-like isozyme was expressed selectively. It may be useful for earlier detection of malignancy to analyze the cancer-associated ALPs, when the small and sequential increase of the serum ALP activity is found in routine laboratory examinations.     

Heat treatment of BMP-2 depots on implant materials generates an immobilized layer of BMP-2 with pronounced bioactivity

Bone cells seeded directly on depots of bone morphogenetic protein-2 (BMP-2) increase alkaline phosphatase (ALP) expression. Heating of such BMP-2 depots to 100 degrees C augmented the intensity of this local ALP induction. To understand this unexpected finding, we investigated the effect of heat treatment on BMP-2 depots more closely. Using a novel bioassay based on ALP-induction of remote cells, we found that the amount of released bioactive BMP-2 from heat-treated depots decays within days and could be described by an exponential function. From this function, we expected that pre-incubation of BMP-2 depots in culture medium for 4 weeks renders them insufficient to induce ALP. However, preincubated, heat-treated depots still induced maximal ALP, unless treated with the selective BMP-2 inhibitor noggin. Furthermore, heat treatment of BMP-2 depots generated a layer of immunoreactive BMP-2 at the surface of the carrier. In contrast, BMP-2 was washed off completely if heat treatment of adsorbed protein was omitted. Results show that heat treatment generates both a soluble pool of BMP-2 and a material-bound layer of BMP-2 in which the protein is protected against degradation. Therefore, heat treatment appears useful to locally immobilize BMP-2 on various implant surfaces.     

热休克对大鼠再灌注性心律失常作用机制的研究

目的:研究热休克预处理对SD大鼠再灌注性心律失常的作用机制。方法:取55只SD大鼠,随机分为热休克组(H组,n=29)和对照组(C组,n=26)。H组大鼠给予热休克预处理而C组则否。取H组和C组各16只大鼠行Langendorff离体心脏灌注及模拟缺血再灌注。心电图记录复灌时心律失常情况。并检测复灌时心脏流出液肌酸激酶(CK)的活性。同时检测两组心脏组织中70kD热休克蛋白(HSP70)的相对含量和抗氧化酶活性。接着对其余13只H组大鼠和10只C组大鼠测定心脏乳头肌动作电位,即测定静息电位、动作电位振幅、0期最大上升速率(Vmax)等电生理指标,再以台氏液复灌,观察心肌动作电位恢复到缺血液灌流前形态的时间。结果:①H组的再灌注性心律失常严重程度明显较C组为轻。②再灌注过程中心肌CK的释放量H组显著少于C组。③H组心脏组织HSP70表达量显著多于C组。④H组抗氧化酶活性明显强于C组,脂质过氧化物少于C组。⑤台氏液灌流时心肌动作电位H组Vmax显著低于C组,提示热休克对心肌的快Na⁺通道有抑制作用。经缺血液灌流10min后,H组的Vmax变化幅度小于C组。以台氏液复灌后,心肌动作电位恢复到缺血液灌流前形态的时间也以H组为短。结论:热休克预处理可以减轻大鼠心肌再灌注性损伤,减少再灌注性心律失常,此作用与心脏组织中HSP70含量的增加和抗氧化酶活性的显著增强有关,同时还可能与热休克对心肌快Na⁺通道的抑制等电生理作用有关。