Heat shock protein (HSP-72) levels in skeletal muscle following work in heat

INTRODUCTION: Acute bouts of heat stress and exercise have been shown to independently increase heat shock protein levels; however, the combination of these two stressors on HSP-72 expression in human skeletal muscle has not been established. The purpose of this study was to determine the effect of a bout of exercise in the heat on HSP-72 expression. METHODS: There were eight recreationally active men (Age = 26.4 +/- 3.1 yr, V(O2)peak = 4.01 +/- 0.25 L min(- 1)) who completed two 30-min bouts of cycle ergometry at 75% of V(O2)peak in a hot (39 degrees C; RH 30%) and cold (9 degrees C; RH 61%) environment. Muscle biopsies were obtained from the vastus lateralis prior to, 6 h post, and 24 h post-exercise to measure HSP-72 protein. Core rectal temperature (Tc), average skin temperature (T(SK)), intramuscular temperature (T(IM)), heart rate (HR), oxygen uptake (V(O2)), sweat rate (SR), and plasma cortisol were measured to determine thermal loads. RESULTS: No significant interactions were present between V(O2) (2.80 +/- 0.2 vs. 2.65 +/- 0.1 L min(-1)) or plasma cortisol (27.1 +/- 2 vs. 19.2 +/- 4 microg dl(-1)) when comparing HT and CD. HR (184 +/- 5 vs. 159 +/- 7 bpm), T(IM) (40.7 +/- 0.2 vs. 40.0 +/- 0.2 degrees C), Tc (38.3 +/- 0.2 vs. 37.9 +/- 0.1 degrees C), T(SK) (36.7 +/- 0.2 vs. 29.6 +/- 0.8 degrees C), and SR (2.0 +/- 0.2 vs. 1.2 +/- 0.2 L h(-1)) were significantly greater when comparing HT and CD. HSP-72 was not altered as a result of either treatment (4.04 +/- 0.87 vs. 2.91 +/- 1.58 ng microg(-1) protein for HT and CD at 6 h post-exercise). DISCUSSION: Exercise in the heat produced a greater thermal load than exercise in the cold; however, no significant increases in HSP-72 were seen when comparing hot and cold conditions.     

Microwave hyperthermia treatment increases heat shock proteins in human skeletal muscle

Objective

To test the hypothesis that microwave hyperthermia treatment (MHT) increases heat shock proteins (HSPs) in the human vastus lateralis muscle.

Methods

Four untrained healthy male volunteers participated in this study. The lateral side of the thigh of one leg (heated leg) was heated with a microwave generator (2.5 GHz, 150 W) for 20 min. At 1 day after the MHT, a muscle sample was taken from the heated leg. A control sample was taken from the unheated leg on another day of the MHT. For both legs, HSP90, HSP72 and HSP27 levels were compared.

Results

The HSP90, HSP72 and HSP27 levels in heated legs were significantly higher than those in control legs (p<0.05).

Conclusions

Application of MHT can increase the levels of several HSPs in human skeletal muscle.Recent papers have proposed that heat shock proteins (HSPs) can prevent contraction‐mediated muscle damage,^1,2 which reduces muscular strength and engenders muscle soreness.³ Therefore, it is expected that a prior increase in HSPs in the skeletal muscle reduces muscle damage and produces better muscle performance.Although HSPs can be increased by many types of stresses, heat stress is often used in the case of skeletal muscle. Indeed, various HSPs are increased by elevating muscle temperature to 40–41°C in rat skeletal muscle.^4,5 However, it has not been investigated whether elevation in muscle temperature increases HSPs in human skeletal muscles. Moreover, the means to increase HSPs have not been established in human skeletal muscle tissue. For these reasons, this study was undertaken to test the hypothesis that microwave hyperthermia treatment (MHT), which is a popular modality of thermotherapy, can increase HSP levels in human skeletal muscle.     

Exercise training increases heat shock protein in skeletal muscles of old rats

PURPOSE: The effects of chronic exercise training on the expression of heat shock protein (HSP) in skeletal muscle of senescent animals are unknown. Therefore, the purpose of this study was to investigate the effects of chronic exercise training on skeletal muscle HSP expression in both young and old rats. METHODS: Young adult (3 months) and old (23 months) female Fisher 344 rats were assigned to either a sedentary control or an endurance exercise trained group (N = 6 per group). Exercised animals ran (60 min.d-1, 5 d.wk-1) on a treadmill at approximately 77% VO2peak for 10 wk. After completion of the training program, the soleus (SOL), plantaris (PL), and the red (RG) and white portions (WG) of the gastrocnemius muscles were excised, and citrate synthase (CS) activity and the relative levels of HSP72 were determined. RESULTS: Training resulted in increases (P < 0.05) in VO2peak in both young (67.6 +/- 3.1 vs 86.9 +/- 1.6 mL.kg-1.min-1) and old animals (54.5 +/- 1.8 vs 68.2 +/- 2.2 mL.kg-1.min-1). Training increased CS activity and the relative levels of HSP72 (P < 0.05) in all four skeletal muscles in both young and old animals. Specifically, compared with age-matched sedentary controls, exercise training resulted in increased (P < 0.05) levels of HSP72 in skeletal muscles of both young (SOL + 22%, PL +94%, RG + 44%, WG + 243%) and old animals (SOL +15%, PL +73%, RG +38%, WG +150%). CONCLUSIONS: These findings reveal that the exercise-induced accumulation of HSP72 in skeletal muscle differs between fast and slow muscles. Further, these data indicate that the exercise-induced accumulation of HSP72 in highly oxidative skeletal muscles (SOL and RG) is similar between young and old animals. In contrast, aging is associated with a blunted expression of HSP72 in fast skeletal muscles (PL and WG) in response to chronic exercise.     

Effects of increased training volume on the oxidative capacity, glycogen content and tension development of rat skeletal muscle

This study examined the effects of a short-term sudden increment in training load on the oxidative capacity, glycogen content and tension-generating ability of rat skeletal muscle. After training on a treadmill 5 dwk-1 for 9 wk (30 m.min-1 6 degrees, 60 min.d-1), rats were randomly divided into a normal training volume (NTV) group (N = 11) and an increased training volume (ITV) group (N = 8). The NTV group were sacrificed 24 h after the last bout of exercise, while the ITV group continued to train for further 6 successive days. Training duration for this latter group was increased to 120 min.d-1 for the first 2 d; 240 min.d-1 for the next 2 d; and 360 min.d-1 for the final 2 d; speed and grade were kept constant. Respiratory capacity (QO2) and citrate synthase activity were increased (P less than 0.05) in both the soleus and plantaris muscles, with no change in the white vastus lateralis muscle of the NTV group when compared to age- matched sedentary controls. Glycogen levels were unchanged in these muscles, but liver glycogen content was greater (231.9 +/- 10.1 vs 156.8 +/- 15.3 umol.g-1 w.w. for the NTV vs age-matched sedentary controls, respectively, P less than 0.05). Peak tetanic tension in the gastrocnemius was not changed by training, or the increased training load. Citrate synthase activity (umol.min-1.g-1) was significantly greater (P less than 0.05) in the plantaris (33.3 +/- 1.0 vs 27.0 +/- 1.7) and soleus muscles (40.5 +/- 2.7 vs 28.4 +/- 1.3) in the ITV vs NTV groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heat shock proteins are important mediators of skeletal muscle insulin sensitivity

Endogenous heat shock proteins (HSP) are decreased in disease states associated with insulin resistance and aging. Induction of HSPs has been shown to decrease oxidative stress, inhibit inflammatory pathways, and enhance metabolic characteristics in skeletal muscle. As such, HSPs have the potential to function as an important defense system against the development of insulin resistance and type 2 diabetes.     

Electrical stimulation-induced changes in skeletal muscle enzymes of men and women.

The purpose of the present study was to determine the effects of low-frequency electrical stimulation (LFES) on the skeletal muscle metabolic profile of men and women. The knee extensor muscles of sedentary men (N = 16) and women (N = 10) were submitted to 3 h.d-1 of 8-Hz neuromuscular electrical stimulation with the use of a portable stimulator (Respond II, Medtronic), 6 d.wk-1 for 6 wk. Enzyme activity levels of creatine kinase (CK), hexokinase (HK), glyceraldehydephosphate dehydrogenase (GAPDH), 3-hydroxyacyl CoA dehydrogenase (HADH), citrate synthase (CS), phosphofructokinase (PFK), and cytochrome c oxidase (COX) were determined in vastus lateralis muscle samples taken before and after the LFES protocol. The analyses of variance revealed no change in CK and in GAPDH. However, a small decrease in PFK activity, the rate-limiting enzyme of glycolysis, was observed in female (8%) and in male subjects (10%), but it reached significance in males only (P < 0.05). The activity level of HK, a regulatory enzyme of the skeletal muscle glucose phosphorylation (HK), increased significantly in female subjects only (36%; P < 0.01) in response to the stimulation protocol. Activity level of marker enzymes of the Krebs cycle (CS) and of the electron-transfert chain (COX) significantly increased in males (18% and 16%; P < 0.05) as well as in females (31% and 19%; P < 0.05). Increment in the marker enzyme activity of the fatty acid oxidation (HADH) was significant in female subjects (30%; P < 0.01) and, although significant, rather modest in male subjects (12%; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

热休克蛋白70在创伤愈合中的作用

目的 探讨热休克蛋白70（heat shock protein70,HSP70）在创伤愈合过程中的变化及其意义。方法 取大鼠伤后1天伤口液作为创伤修复启动微环境,刺激真皮多能干细胞,24小时后检测细胞表达HSP70含量的变化。同时制作单纯创伤和难愈创伤动物模型,通过免疫组化和图像分析方法观察伤后不同时相点伤口组织HSPT0含量变化。结果 创伤早期伤口液作用真皮多能干细胞后,HSP70表达显著增加。单纯创伤组大鼠伤后各时相点伤口局部HSP70表达均显著增加,尤以真皮组织增加明显,其峰值为伤后3天。难愈创伤组大鼠伤口局部HSP70含量在伤后各时相点亦显著增加,但与单纯创伤组相比,其含量在伤后各时相点均显著减少,尤以真皮组织表达减少更为明显,并且HSP70表达峰值显著延迟,为伤后7天。结论 HSP70不仅是一种应激保护分子,而且还是参与调节创伤愈合的一种重要分子。     

Peak oxygen consumption and skeletal muscle bioenergetics in African-American and Caucasian men

OBJECTIVE: To compare peak oxygen consumption (VO2peak) and skeletal muscle oxidative metabolism between nine African-American and nine Caucasian men. METHODS: Subjects performed arm ergometry to exhaustion. On a separate occasion 31phosphorous-nuclear magnetic resonance spectroscopy (31P-NMRS) was used to determine the concentrations of phosphorous (Pi), phosphocreatine (PCr), and the intracellular pH of the flexor carpi radialis before and during 4 min of steady-state, wrist flexion exercise performed at 28% (15 W) of each subject's peak voluntary contraction. RESULTS: The Pi/PCr ratio was used as an indirect measure of skeletal muscle oxidative metabolism. VO2peak was lower in the African-Americans compared with the Caucasians (means +/- SD, 19.4 +/- 3.4 vs 23.3 +/- 4.0 mL x kg(-1) x min(-1)) (P < 0.05). No significant between group difference was noted in the Pi/PCr ratio at rest (0.10 +/- 0.02 both groups). However, resting pH was lower in the African-Americans (6.99 +/- 0.04 vs 7.03 +/- 0.05) (P < 0.05). Exercise caused an increase in the Pi/PCr ratio in the African-Americans (1.06 +/- 0.11), which was higher than the increase observed in the Caucasians (0.50 +/- 0.14) (P < 0.05). pH levels decreased to a lower level during exercise in the African-Americans (6.89 +/- 0.04) than in the Caucasians (6.98 +/- 0.05) (P < 0.05). CONCLUSIONS: This select group of African-American men achieved a lower VO2peak than the Caucasian men. Variations in skeletal muscle oxidative metabolic components may explain this difference.     

Training alters the skeletal muscle antioxidative capacity in non-insulin-dependent type 2 diabetic men

The present study analyzes the oxidative stress situation in the skeletal muscle of overweight/obese men suffering from non-insulin-dependent type 2 diabetes mellitus [T2DM, n=16, years=61±7, body mass index (BMI)=31±4 kg/m(2) ] and BMI-matched non-diabetic male control subjects (CON, n=7, years=53±6, BMI=30±4 kg/m(2) ). Furthermore, it investigates whether physical training can alter the skeletal muscle antioxidative capacity of T2DM patients at rest. Molecule content analyses (immunohistochemical stainings) of 8-iso-prostaglandin-F2α (8-Iso-PGF), superoxide dismutase-2 (SOD2), glutathione peroxidase-1 (GPX1), peroxiredoxin isoforms (PRDX 1-6) and heat-shock-protein-70 (HSP70) were performed in biopsies taken from the vastus lateralis muscle. Under basal conditions, 8-Iso-PGF was significantly decreased in T2DM patients (-35.7%), whereas PRDX2 and PRDX6 were significantly increased relative to CON (+82.6%; +82.3%). Differences were neither observed in SOD2 nor in GPX1 or PRDX1, 3, 4, 5 density. Regular physical activity (moderate endurance or resistance training twice a week for 3 months) did not alter PRDX1, 2, 3, 4, 6 in the skeletal muscle of T2DM patients, but significantly increased SOD2 (+65.9%), GPX1 (+62.4%), PRDX5 (+37.5%), and HSP70 (+48.5%). Overweight/obese men with non-insulin-dependent T2DM exhibit up-regulated cytosolic peroxiredoxin contents relative to BMI-matched controls. Regular training further up-regulates cytosolic and mitochondrial antioxidative enzymes in T2DM patients and improves their cellular protection systems. This may contribute to a retardation of the disease's progression.     

热休克蛋白70封闭后对星形胶质细胞反应性增生的影响

目的 探讨用抗体封闭热休克蛋白70(heat shock protein 70,HSP70)后对星形胶质细胞反应性增生的影响. 方法 原代培养并纯化星形胶质细胞,采用划痕损伤法构建细胞损伤模型,通过培养液内加入HSP70抗体来进行干预.在不同时间点对损伤对照组和损伤干预组进行胶质纤维酸性蛋白(GFAP)免疫细胞化学染色,观察细胞增生情况及形态学变化,并用RT-PCR检测GFAP mRNA的表达. 结果 与对照组相比,干预组细胞面积、突起数目及突起长度均减小(P<0.05或0.01),GFAP mRNA的表达也明显降低(P<0.05). 结论 星形胶质细胞损伤后,HSP70有促进星形胶质细胞反应性增生的作用.用抗体封闭HSP70后,能够一定程度上抑制星形胶质细胞的反应性增生.     

Leukocyte heat shock protein expression before and after intensified training

The purpose of the current research was to test the hypothesis that exercise induced leukocyte heat shock protein (HSP) expression is increased during periods of intensified exercise training. Seven male endurance cyclists carried out tests of maximal oxygen consumption and endurance capacity. These standard exercise tests were carried out prior to and following 6 days of prescribed intensified training. Sampled leukocytes were examined for Hsp27 and Hsp70 expression using a Fluorescence Activated Cell Scanner (EPICS XL, Coulter). During a period of overreaching, as signified by a drop in time to fatigue following the intensified training period (p = 0.02), the number of extracellular Hsp27 positive granulocytes increased in response to the VO(2)max test. Acute, intracellular HSP responses were observed in both baseline and overreached conditions. The present study showed that a period of intensified training caused adaptations in the acute heat shock protein exercise response, reflected by a greater increase of cell surface HSP positive leukocytes following heavy training.     

热休克蛋白与脑损伤的研究进展

热休克蛋白 (heatshockproteins ,HSPs)是指热应激时细胞新合成或合成增加的一类蛋白质 ,首次是从热应激果蝇幼虫的唾液腺等部位分离出来并命名。后来研究发现 ,除热应激外 ,多种损伤性因素可使组织细胞HSPs合成增加 ,它可保护机体在严酷的环境下得以生存。HSPs是一个大家族 ,现已发现的成员包括HSP1 1 0、HSP90家族、HSP70家族、HSP60、低分子量HSP、HSP1 0和泛素(ubiquitin)。正常生理情况下 ,中枢神经系统内并无HSPs的表达。近年来 ,国内外关于HSPs在脑损伤后的表达的研究十分活跃 ,已经发现缺血、创伤、氧化应激等均可导…     

热应激下热休克蛋白70对细胞保护作用研究进展

热休克反应（heat shock response,HSR）是一切有生命细胞遇短暂高温、缺氧、亚砷酸盐及H2O2等应激原刺激时,所发生的一种以基因表达和调控变化为特征的细胞应激反应。HSR启动热休克基因表达,产生一组高度保守的热休克蛋白（heat shock proteins,HSPs）。而热休克蛋白（HSPs）是一类广泛存在所有原核和真核细胞内,具有高度保守性的蛋白家族。当生物细胞受到应激刺激（如热、缺血、缺氧、病毒感染等）和其损伤因素作用而发生应激反应时,就会自动启动HSPs合成基因,促使HSPs的合成,以对细胞起一定的保护作用。有人根据其分子量、等电点将HSPs分成5大类（或家族）,分别为低分子量HSPs家族、中等分子量HSPs家族、HSP70家族、HSP90家族和HSP110家族。几乎所有的细胞均能合成HSPs,其中HSP70家族含量最多亦是最重要的HSPs。目前认为HSP70具有多种功能,是一种非特异性细胞保护蛋白,因此是最受关注、研究最多的一种HSPs。     

热休克蛋白在心肌缺血再灌注损伤中的作用

热休克蛋白是近年来研究较多的生物体内内源性保护因子 ,许多原因如高温、缺血、缺氧均可使热休克蛋白合成增加 ,且生成量与心肌保护程度呈直接关系。其中时间因素很重要。本篇就热休克蛋白及其与心肌缺血再灌注损伤之间的关系作一综述。1　热休克蛋白概述　　热休克蛋白 (ＨｅａｒｔＳｈｏｃｋＰｒｏｔｅｉｎ ,ＨＳＰ)是指细胞在应激原诱导下生成的一组蛋白质 ,最早由Ｒｉｔｏｓｓａ〔1〕于 196 2年在果蝇唾液腺中发现 ,直到 1974年Ｔｉｓｓｅｒｅｓ将其从果蝇体中分离出来 ,并命名为热休克蛋白。热休克蛋白是一类在进化上高度保守、广泛存…     

Myosin and actin content of human skeletal muscle fibers following 35 days bed rest

Biopsy samples were taken from the vastus lateralis muscle of seven male subjects pre- and post-35 days bed rest (BR). The myosin heavy chain (MHC) isoform distribution of the samples was determined by densitometry of MHC bands separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Individual muscle fibers were dissected from biopsy samples pre-BR ( n =143) and post-BR ( n =144). They were studied as regards cross-sectional area (CSA), myosin content by quantitative electrophoresis and myosin actin (M/A) ratio by densitometry of myosin and actin bands of individual muscle fibers. All fibers were typed according to their MHC isoform content determined by SDS-PAGE. A decrease in MHC-1 relative content and an increase in MHC-2X content of whole muscle samples were found, suggesting a slow to fast shift in muscle phenotype. Consistently, fiber type distribution was shifted toward type 2X and 2AX fibers. Muscle fiber atrophy occurred at variable extent among fiber types. Myosin concentration was significantly lower in type 1 and type 2A muscle fibers post-BR than pre-BR, whereas M/A ratio did not vary. The latter findings indicate a disproportionate loss of myosin compared with fiber CSA and a proportional loss of myosin and actin.     

热休克蛋白在宫颈病变中的表达

目的研究几种主要热休克蛋白（heat shock protein, HSP）在不同病理改变的宫颈组织中的表达.方法根据病理诊断,把478例宫颈活检标本分为宫颈癌组（63例）、宫颈上皮内瘤形成组（CIN组,106例）、宫颈炎组（293例）及正常宫颈组（16例）.采用以特异性复合cRNA为内参照的定量RT-PCR法,检测各组标本的HSP70、HSP90α和HSP90β mRNA的表达.结果 （1）HSP70、HSP90α和HSP90β mRNA在宫颈浸润癌、CIN、宫颈炎及正常宫颈组织中的表达量均呈现阶梯式下降,差异均有极显著意义（P＜0.01）.（2）HSP90β mRNA在晚期宫颈癌中的表达比早期表达高（P＜0.05）;HSP70和HSP90β mRNA在低分化宫颈癌中的表达比高分化表达高（P＜0.05）;而HSP70、HSP90α和HSP90β mRNA在不同组织类型宫颈癌中的表达均无显著性差异（P＞0.05）.结论热休克蛋白在宫颈癌的发生和发展中起着重要的协同作用.HSP70和HSP90α与宫颈癌细胞的转化和增殖密切相关,HSP90β可能参与细胞的分化.     

人肝细胞肝癌组织中p53蛋白和热休克蛋白70的表达

目的：进行抗人肝癌的肿瘤主动性免疫研究,初步探讨人肝细胞肝癌（HCC）中p53蛋白及热休克蛋白70（HSP70）的表达并分析其间的关系。方法：免疫组织化学Envision法。结果：p53蛋白及HSP70均定位于细胞核或／和细胞质中。HCC中p53蛋白及HSP70阳性率分别为56．60％及49．06％;p53阳性者中88．68％伴有HSP70阳性,而HSP70阳性者中96．23％同时有p53阳性。结论：HCC中p53蛋白及HSP70表达增高,两者表达间有相关性。