Identification of heat shock protein hsp70 family genes from Rana amurensis and its expression profiles upon infection / 生物工程学报

Heat shock proteins (HSPs) widely exist in all organisms, the structures of which are usually extraordinarily conservative. They are also well-known stress proteins that are involved in response to physical, chemical and biological stresses. HSP70 is an important member of the HSPs family. In order to study the roles of amphibians HSP70 during infection, the cDNA sequence of Rana amurensis hsp70 family genes were cloned by homologous cloning method. The sequence characteristics, three-dimensional structure and genetic relationship of Ra-hsp70s were analyzed by bioinformatics methods. The expression profiles under bacterial infection were also analyzed by real-time quantitative PCR (qRT-PCR). Expression and localization of HSP70 protein were tested by immunohistochemical techniques. The results showed that three conservative tag sequences of HSP70 family, HSPA5, HSPA8 and HSPA13, were found in HSP70. Phylogenetic tree analysis indicated four members are distributed in four different branches, and members with the same subcellular localization motif are distributed in the same branch. The relative expression levels of the mRNA of four members were all significantly upregulated (P < 0.01) upon infection, but the time for up-regulating the expression levels were diverse in different tissues. The immunohistochemical analysis showed that HSP70 was expressed to different degrees in the cytoplasm of liver, kidney, skin and stomach tissue. The four members of Ra-hsp70 family have ability to respond bacterial infection to varying degrees. Therefore, it was proposed that they are involved in biological processes against pathogen and play different biological functions. The study provides a theoretical basis for functional studies of HSP70 gene in amphibians.

Estresse oxidativo e diminuição de HSP70 tecidual envolvidos na gênese da sepse: HSP70 como alvo terapêutico / Oxidative stress and decreased tissue HSP70 are involved in the genesis of sepsis: HSP70 as a therapeutic target

RESUMO A sepse é uma infecção sistêmica que acarreta disfunção múltipla dos órgãos. A HSP70 é uma proteína responsiva ao estresse celular, assim como o estresse oxidativo. Esta revisão da literatura buscou investigar a HSP70 e o estresse oxidativo quanto à fisiopatologia da sepse e ao papel da HSP70 como possível alvo terapêutico. A HSP70 exerce efeito protetor quando localizada na célula (iHSP70), e sua diminuição, assim como seu aumento no ambiente extracelular (eHSP70) e o estresse oxidativo, é um biomarcador de gravidade na sepse. Além disso, terapias que aumentam a iHSP70 ou o próprio tratamento com HSP70 promovem a melhora na sepse.

Abstract Sepsis is a systemic infection that causes multiple organ dysfunction. HSP70 is a protein responsive to cell stress, in particular oxidative stress. Therefore, this literature review sought to investigate the roles of HSP70 and oxidative stress in the pathophysiology of sepsis and the possibility of HSP70 as a therapeutic target. HSP70 exerts a protective effect when located in cells (iHSP70), and its decrease, as well as its increase in the extracellular environment (eHSP70), under oxidative stress is a biomarker of sepsis severity. In addition, therapies that increase iHSP70 and treatment with HSP70 promote sepsis improvement.

Aqueous humor heat-shock protein 70, periostin, and irisin levels in patients with pseudoexfoliation syndrome / Níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso em pacientes com pseudoexfoliação

ABSTRACT Purpose: To measure humor heat-shock protein 70, periostin, and irisin levels in patients with pseudoexfoliation syndrome and cataract (without glaucoma), and compare them with those of patients with cataract but without pseudoexfoliation. Methods: We examined 31 eyes of 31 patients with pseudoexfoliation and cataract (without glaucoma) and 30 eyes of 30 patients with cataract. We collected aqueous humor samples from all patients at the time of cataract surgery through a limbal paracentesis via a 25-gauge cannula mounted on a tuberculin syringe that received 100 to 150 µL of aqueous humor. We measured levels of aqueous humor Heat shock protein 70, periostin, and irisin using enzyme-linked immunosorbent assay methods. Results: The age (p=0.221) and gender (p=0.530) means were similar between the pseudoexfoliation and control groups. The mean Heat shock protein 70 level (29.22 ± 9.46 ng/mL; 17.88-74.46) in the pseudoexfoliation group was significantly higher than that in the control group (19.03 ± 7.05 ng/mL; 9.93-35.52; p<0.0001). The mean periostin level was significantly higher (6017.32 ± 1271.79 pg/mL; 3787.50-10803.57) in the pseu doexfoliation group than that in the control group (4073.63 ± 1422.79 pg/mL; 2110.44-7490.64; p<0.0001). The mean irisin level (53.77 ± 10.19 ng/mL; 29.46-71.16) was significantly higher than that in the control group (39.29 ± 13.58 ng/mL; 19.41-70.56; p<0.0001). Conclusions: Heat shock protein 70, periostin, and irisin levels increase in the aqueous humor of patients with pseudoexfoliation without glaucoma.

RESUMO Objetivo: Comparar os níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso de pacientes com pseudoexfoliação com catarata sem glaucoma e compará-los com pacientes com catarata sem pseudoexfoliação. Métodos: Trinta e um olhos de 31 pacientes com pseudoexfoliação com catarata sem glaucoma e 30 olhos de 30 indivíduos com catarata foram incluídos neste estudo. Amostras de humor aquoso foram coletadas de todos os pacientes no momento da cirurgia de catarata e obtidas através de uma paracentese límbica por meio de uma cânula de calibre 25 acoplada a uma seringa com tuberculina. Foram coletados 100 a 150 µL de humor aquoso. Os níveis de proteína de choque térmico 70, de periostina e de irisina no humor aquoso foram medidos usando o método de ensaio imunossorvente ligado a enzima. Resultados: A média da idade (p=0,221) e sexo (p=0,530) foram semelhantes entre os grupos pseudoexfoliação e controle. Os níveis médios de proteína de choque térmico 70 foram 29,22 ± 9,46 ng/mL (17,88-74,46) e 19,03 ± 7,05 ng/ mL (9,93-35,52) nos grupos pseudoexfoliação e controle, respectivamente. Os níveis de proteína de choque térmico 70 foram maiores no grupo pseudoexfoliação (p<0,0001). O nível médio de periostina foi de 6017,32 ± 1271,79 pg/mL (3787,50-10803,57) no grupo pseudoexfoliação e 4073,63 ± 1422,79 pg/mL (2110,44-7490,64) no grupo controle. O nível médio de periostina também foi maior no grupo pseudoexfoliação (p<0,0001). Os níveis médios de irisina foram 53,77 ± 10,19 ng/mL (29,46-71,16) e 39,29 ± 13,58 ng/mL (19,41-70,56) nos grupos pseudoexfoliação e controle, respectivamente. O nível médio de irisina foi maior no grupo pseudoexfoliação do que no grupo controle (p<0,0001). Conclusões: Os níveis de proteína de choque térmico 70, de periostina e de irisina aumentam no humor aquoso de pacientes com pseudoexfoliação sem glaucoma.

HSP70 from the Antarctic sea urchin Sterechinus neumayeri: molecular characterization and expression in response to heat stress

Abstract Background: Heat stress proteins are implicated in stabilizing and refolding denatured proteins in vertebrates and invertebrates. Members of the Hsp70 gene family comprise the cognate heat shock protein (Hsc70) and inducible heat shock protein (Hsp70). However, the cDNA sequence and the expression of Hsp70 in the Antarctic sea urchin are unknown. Methods: We amplified and cloned a transcript sequence of 1991 bp from the Antarctic sea urchin Sterechinus neumayeri, experimentally exposed to heat stress (5 and 10 °C for 1, 24 and 48 h). RACE-PCR and qPCR were employed to determine Hsp70 gene expression, while western blot and ELISA methods were used to determine protein expression. Results: The sequence obtained from S. neumayeri showed high identity with Hsp70 members. Several Hsp70 family features were identified in the deduced amino acid sequence and they indicate that the isolated Hsp70 is related to the cognate heat shock protein type. The corresponding 70 kDa protein, called Sn-Hsp70, was immune detected in the coelomocytes and the digestive tract of S. neumayeri using a monospecific polyclonal antibody. We showed that S. neumayeri do not respond to acute heat stress by up-regulation of Sn-Hsp70 at transcript and protein level. Furthermore, the Sn-Hsp70 protein expression was not induced in the digestive tract. Conclusions: Our results provide the first molecular evidence that Sn-Hsp70 is expressed constitutively and is noninduced by heat stress in S. neumayeri.

Strong renal expression of heat shock protein 70, high mobility group box 1, inducible nitric oxide synthase, and nitrotyrosine in mice model of severe malaria

Abstract INTRODUCTION Renal damage is a consequence of severe malaria, and is generally caused by sequestration of Plasmodium falciparum -infected erythrocytes in the renal microcirculation, which leads to obstruction, hypoxia, and ischemia. This triggers high mobility group box 1 (HMGB1) to send a danger signal through toll-like receptors 2 and 4. This signal up-regulates inducible nitric oxide (iNOS) and nitrotyrosine to re-perfuse the tissue, and also increases heat shock protein 70 (HSP70) expression. As no study has examined the involvement of intracellular secondary molecules in this setting, the present study compared the renal expressions of HSP70, HMGB1, iNOS, and nitrotyrosine between mice suffered from severe malaria and normal mice. METHODS C57BL/6 mice were divided into an infected group (intraperitoneal injection of 10 6 P. berghei ANKA) and a non-infected group. Renal damage was evaluated using hematoxylin eosin staining, and immunohistochemistry was used to evaluate the expressions of HSP70, HMGB1, iNOS, and nitrotyrosine. RESULTS Significant inter-group differences were observed in the renal expressions of HSP70, HMGB1, and iNOS (p=0.000, Mann-Whitney test), as well as nitrotyrosine (p=0.000, independent t test). The expressions of HSP70 and HMGB1 were strongly correlated (p=0.000, R=1.000). No correlations were observed between iNOS and HMGB, HMGB1 and nitrotyrosine, HSP70 and nitrotyrosine, or iNOS and nitrotyrosine. CONCLUSIONS It appears that HMGB1, HSP70, iNOS, and nitrotyrosine play roles in the renal damage that is observed in mice with severe malaria. Only HSP70 expression is strongly correlated with the expression of HMGB1.

Physiological regulation of the heat shock response by glutamine: implications for chronic low-grade inflammatory diseases in age-related conditions

Aging is an intricate process modulated by different molecular and cellular events, such as genome instability, epigenetic and transcriptional changes, molecular damage, cell death and senescence, inflammation, and metabolic dysfunction. Particularly, protein quality control (chaperone systems) tends to be negatively affected by aging, thus leading to cellular senescence in metabolic tissues and, as a consequence, to the increasing dissemination of inflammation throughout the body. The heat shock (HS) response and its associated expression of the 70 kDa family of heat shock proteins (HSP70),which are anti-inflammatory molecular chaperones, are found to be markedly decreased during muscle inactivity and aging, while evidence supports the loss of HSP70 as a key mechanism which may drive muscle atrophy, contractile dysfunction, and reduced regenerative capacity. In addition, abnormal stress response is linked with higher incidence of neurodegenerative diseases as well as low-grade inflammatory diseases that are associated with physical inactivity and obesity. Therefore, strategies to increase or, at least, to maintain the levels of HSP70, and its accompanying HS response to stress, are key to reduce biological cell dysfunctions that occur in aging. In this sense, physical exercise is of note as it is the most powerful inducer of the HS response, comparable only to heat stress and fever-like conditions. On the other hand, the amino acidL-glutamine, whose production within the skeletal muscle and liberation into the bloodstream is dependent on muscle activity, is a potentializer of HSP70 expression and HS response, particularly via its entering in hexosamine biosynthetic pathway (HBP). Herein, we discuss the collaborative role of glutamine (and its donors/precursors) and physical exercise (mostly responsible for glutamine release into the circulation) as potential tools to increase HSP70 expression and the HS response in the elderly.

Expression of CAIII and Hsp70 Is Increased the Mucous Membrane of the Posterior Commissure in Laryngopharyngeal Reflux Disease

PURPOSE: We tried to evaluate the difference in the expression of carbonic anhydrase (CA) III and heat shock protein (Hsp) 70 between laryngopharyngeal reflux disease (LPRD) and non-LPRD patients. MATERIALS AND METHODS: The study involved 28 patients who underwent laryngeal microsurgery due to benign laryngeal disease from March to August 2008. Reflux symptom index (RSI) and reflux finding score (RFS) were measured for each person, and they were assigned either to the LPRD group (n=10) or non-LPRD group (n=18). Tissue samples were obtained from the mucosa of posterior commissure, and immunohistochemistry (IHC) staining of CAIII and Hsp70 was performed. The IHC scores were measured and compared with clinical features including RSI and RFS. RESULTS: Total 10 patients were assigned as LPRD group, and 18 patients were as control group. The mean IHC score of CAIII and Hsp70 was 1.70+/-1.06 and 1.90+/-0.88, respectively, in LPRD patients, whereas the mean IHC score of CAIII and Hsp70 was 0.78+/-0.73 and 0.94+/-0.87, respectively, in non-LPRD patients. The difference between two groups was statistically significant (p<0.05). CONCLUSION: CAIII and Hsp70 expressions were higher in LPRD patients that in non-LPRD patients, suggesting the possibility as one of biomomarker in LPRD diagnosis.

Cardiac Ultrastructure and Changes of HSP70 and HIF-1α Expression in Electric Shock Death Rats / 法医学杂志

OBJECTIVE@#To observe cardiac ultrastructure and the expression of heat shock protein 70 (HSP70) and hypoxia inducible factor-lα (HIF-lα) in electric shock death rats and to explore the application of these indexes as the basis of medical identification in electric shock death.@*METHODS@#Seventy-two SD rats were randomly divided into electric shock death group, postmortem electric shock group and the control group. The changes of myocardial ultrastructure were observed by transmission electron microscope, and the expressions of myocardial HSP70 and HIF-1α were observed by immunohistochemical technology.@*RESULTS@#Myocardial myofibril fracture, mitochondrial cristae and membrane dissolution, and disordered arrangement of Z lines and M lines were observed in electric shock rats. HSP70 and HIF-lα were strong positive expressions in the electric shock death group, significantly compared with the control and postmortem electric shock groups (P < 0.05).@*CONCLUSION@#The expressions of HSP70 and HIF-lα were obviously increased in electric shock death group, which may be used as the diagnostic indicator of electric shock death.

Prognostic Significance of p53, mTOR, c-Met, IGF-1R, and HSP70 Overexpression after the Resection of Hepatocellular Carcinoma

BACKGROUND/AIMS: The current study examines the expression of molecular biomarkers in hepatocellular carcinoma (HCC) and whether these findings correlate with the clinicopathologic features of the disease and patient survival. METHODS: We analyzed the immunohistochemical expression of p53, mammalian target of rapamycin (mTOR), c-Met, and insulin-like growth factor 1 receptor (IGF-1R) heat shock protein 70 (HSP70) with the clinicopathologic features of 83 HCCs. RESULTS: p53 expression was higher in the male patients with undifferentiated histological tumor grades, cirrhosis, and portal vein invasion. High 48 c-Met expression correlated with cirrhosis, and high mTOR expression correlated with the tumor grade and cirrhosis. High IGF-1R expression correlated with the tumor grade and cirrhosis. A multivariate analysis identified a significant relationship between the high expression of p53, tumor grade, and portal vein invasion. In addition, a high expression of mTOR was related to tumor grade and cirrhosis, and a high expression of HSP70 was related to portal vein invasion in a multivariate analysis. The Kaplan-Meier survival curve for patients with high versus low Edmondson grades and p53 expression was statistically significant. CONCLUSIONS: p53, mTOR, and IGF-1R expression correlated with the Edmondson tumor grade in a univariate analysis, while p53 and mTOR correlated with the Edmondson tumor grade in a multivariate analysis. In addition, the tumor grade was found to predict survival. p53 was primarily related to the clinicopathologic features compared to other markers, and it is a poor prognostic factor of survival.

Antiaging, antistress and ROS scavenging activity of crude extract of Ocimum sanctum (L.) in Caenorhabditis elegans (Maupas, 1900).

Since aging is the most important risk factor for variety of diseases, the discovery of a wide range of chemical modulators of aging in model organisms encourages new strategies for targeting age associated diseases. Simple genetic manipulation leads to long-lived and healthy animals, so any compound which could have similar effect would prove a boon to mankind. In the present study, effect of different pharmacological doses (1.0, 0.1, 0.01 and 0.001 mg/mL) of O. sanctum crude extract were used to determine their impact on life span, thermotolerance and ROS scavenging activities in C. elegans. The results revealed that 1 mg/mL of O. sanctum extract significantly extended the life span of C. elegans. The extract also proved to be a strong free radical scavenger and increased resistance against thermal stress. It is also suggested that the protective and life span extending action of the crude extract is not only due to its antioxidant capacity but may also be mediated by modulation of some signaling pathways. Thus, in addition to all the known medicinal property of Ocimum, it is capable of increasing stress tolerance and life span in C. elegans.

Expression of Heat Shock Protein 70 Modulates the Chemoresponsiveness of Pancreatic Cancer

BACKGROUND/AIMS: Heat shock protein (HSP) 70 is constitutively overexpressed in pancreatic cancer cells (PCCs) and appears to confer protection against chemotherapeutics. We investigated whether modulating HSP 70 increases chemoresponsiveness to gemcitabine in PCCs. METHODS: Varying concentrations of quercetin and gemcitabine, either alone or in combination, were added to PCCs (Panc-1 and MiaPaCa-2). MTT assay was performed to analyze cell viability. HSP 70 expression was assessed by Western blot analysis. Apoptosis was determined by measuring caspase-3 activity. Western blot for the LC3-II protein detected the presence of autophagy. RESULTS: HSP 70 levels were not affected by the incubation of Panc-1 and MiaPaCa-2 cells with gemcitabine, whereas with quercetin, the levels were reduced in both cell lines. The viability of both Panc-1 and MiaPaCa-2 cells significantly decreased with gemcitabine treatment but not with quercetin. A combination of gemcitabine and quercetin decreased the viability of both cell lines in a dose-dependent manner, which was more pronounced than gemcitabine treatment alone. Treatment with either gemcitabine or quercetin augmented caspase-3 activity in both cell lines, and a combination of these compounds further potentiated caspase-3 activity. LC3-II protein expression was negligible with gemcitabine treatment but marked with quercetin. The addition of gemcitabine to quercetin did not potentiate LC3-II protein expression. CONCLUSIONS: Modulation of HSP 70 expression with quercetin enhanced the chemoresponsiveness of PCCs to gemcitabine. The mechanism of cell death was both apoptosis and autophagy.

Hsp70 and HSF-1 expression is altered in the tissues of pigs transported for various periods of times

The aim of this study was to assess changes of Hsp70 and HSF-1 protein and mRNA expression in stress-sensitive organs of pigs during transportation for various periods of time. Twenty pigs were randomly divided into four groups (0 h, 1 h, 2 h, and 4 h of transportation). A significant increased activity of AST and CK was observed after 1 h and 2 h of transportation. Histopathological changes in the heart, liver, and stomach indicated that these organs sustained different degrees of injury. Hsp70 protein expression in the heart and liver of transported pigs did not change significantly while it increased significantly (p < 0.05) in the stomach. Hsp70 mRNA levels decreased significantly (p < 0.05) in the heart after 4 h of transportation. However, mRNA expression increased significantly in the liver after 1 (p < 0.05) and 4 h (p < 0.01) of transportation, and increased significantly in the stomach of the transported pigs after 1, 4 (p < 0.01), and 2 h (p < 0.05). HSF-1 levels were reduced at 1 and 4 h (p < 0.05) only in the hearts of transported pigs. These results indicate that Hsp70 mediates distinct stress-related functions in different tissues during transportation.

HSP70 Expression and its Role in Preeclamptic Stress.

Preeclampsia, a hypertensive pregnancy-specific disorder, has long been analyzed for its association with cellular stress. It still remains one of the most serious complications of pregnancy. It is a multi-system disorder that affects maternal vascular function and fetal growth. The physiopathology of preeclampsia is still unclear, but an imbalance between reactive oxygen species (ROS) and antioxidants, appears to be an important contributing factor. Oxidative stress has been increasingly postulated as a major contributor to endothelial dysfunction in preeclampsia (PE). The ROS promotes lipid oxidation and are known to induce stress proteins, such as hemeoxygenase 1 (HO-1) and heat-shock protein 70 (HSP70). Embryonic and placental cells are highly sensitive to oxidative stress due to their proliferate nature. Endothelial cell dysfunction is suggested to be a part of wider maternal inflammatory reaction responsible for the clinical syndrome of preeclampsia. Part of the dysfunction in endothelial cell and trophoblast is attributed to oxidative stress developed during pregnancy. The disequilibrium in compensatory antioxidant control is proposed as a causative mechanism in the pathophysiology of preeclampsia. HSP70 acts as the secondary line of defense in systems with compromised antioxidant function. This article reviews the differential expression of HSP70 and the effect of mint-tea therapy to modulate preeclamptic oxidative damage.

Expression of HSP70 mRNA in hippocampus of rats after diffuse axonal injury / 法医学杂志

OBJECTIVE@#To explore the changes of expression of heat-shock proteins (HSP) 70 mRNA in hippocampus of rats after diffuse axonal injury (DAI).@*METHODS@#RT-PCR products of HSP70 mRNA were tested by agarose gel electrophoresis after RT-PCR amplification. The changes of HSP70 mRNA expression were observed in rat hippocampus after DAI.@*RESULTS@#The expression of HSP70 mRNA in the hippocampus could be detected 4 h after DAI. It reached maximum at 24 h and declined after 48 h.@*CONCLUSION@#HSP70 mRNA in hippocampus of rats could be useful for diagnosis of DAI.

The expressions of HSP70 and alphaB-crystallin in myocarditis associated with foot-and-mouth disease virus in lambs

This study describes the expression of heat shock protein70 (HSP70) and alpha-basic-crystallin (alpha-BC) and their association with apoptosis and some related adaptor proteins in the pathogenesis of foot-and-mouth disease virus (FMDV)-induced myocarditis in lambs. HSP70 was generally overexpressed in the myocardial tissues and inflammatory cells of FMDV-induced myocarditis with differential accumulation and localization in same hearts when compared to non-foot-and-mouth disease control hearts. alpha-BC immunolabeling showed coarse aggregations in the Z line of the cardiomyocytes in FMDV-infected hearts in contrast to control hearts. Overall, the results of this study show that the anti-apoptotic proteins, HSP70 and alpha-BC, were overexpressed with increased apoptosis in FMDV-infected heart tissues. Both proteins failed to protect the cardiomyocytes from apoptosis as defense mechanisms to the FMDV during the infection, suggesting that the virus is able to increase apoptosis via both downregulation and/or upregulation of these anti-apoptotic proteins.

Hsp90 mediates activation of the heme regulated eIF-2 kinase during oxidative stress.

The heme-regulated inhibitor (HRI), a member of the eIF-2 kinase family is crucial for regulating protein synthesis during stress. In addition to heme, stress proteins Hsp90 and Hsp70 are known to regulate HRI. The present study aims to determine the physical association of these Hsps in the regulation of HRI activation during oxidative stress using human K562 cells as a model. Extracts from the stress-induced cells were used for determining HRI kinase activity by measuring eIF-2 phosphorylation, and Hsp-HRI interaction by immunoprecipitation and immunoblot analyses. The results indicate a significant increase in both Hsp70 and Hsp90 expression during AAPH (2, 2’-azobis (2-amidinopropane) dihydrochloride)-induced oxidative stress. Further, their interaction with HRI, which correlates well with its increased HRI kinase activity leads to inhibition of protein synthesis. Thus, we demonstrate that Hsps play an important role in the regulation of initiation of protein synthesis during oxidative stress.

Changes of HSP70, bFGF and TGF-beta1 expression in rat brain after concussion / 法医学杂志

OBJECTIVE@#To study the changes of expression of relevant factors in rat brain after concussion injury and to provide scientific basis for forensic estimation of brain injury interval.@*METHODS@#Brain tissues were sampled from the established SD rat animal model of brain concussion, routinely processed and stained with HE and immunohistochemically stained with antibodies directed against heat shock protein 70 (HSP70), transforming growth factor beta 1 (TGF-beta1) and basic fibroblast growth factor (bFGF). The sections were examined under light microscope with IMAGE analytical system and homologous statistical analysis.@*RESULTS@#The expression of HSP 70 was observed in 30 minutes after brain injury. The amount of neurons expressing HSP 70 increased gradually, reached its peak at 12 hours and then declined at 24 hours after brain injury. The expression of bFGF was observed 3 hours after injury in brain stem, reached its peak at 12 hours, and then declined. The expression of TGF-beta1 was detected 6-24 hours after brain injury, remained at its peak up to 3 days.@*CONCLUSION@#Brain injury can induce a chronological expression of HSP70, bFGF and TGF-beta1. The results can be a potential for estimating the age of brain injury using several markers.

The expressions of HSP 70 mRNA and c-fos mRNA in the skeletal muscle and cardiac muscle of rabbits by electrocuted / 法医学杂志

OBJECTIVE@#To study the changes of HSP 70 mRNA and c-fos mRNA expression and to find a method to differentiate antemortem from postmortem electrocution.@*METHODS@#Fifteen New Zealand rabbits were randomly divided into three groups, the antemortem electrocution group, the postmortem electrocution group, and the control group. Each group consists of five rabbits. The levels of HSP 70 mRNA and c-fos mRNA in skeletal muscle and cardiac muscle were examined with quantitative fluorescent RT-PCR.@*RESULTS@#The levels of HSP 70 mRNA and c-fos mRNA in the antemortem electrocution group increased significantly (P<0.05), compared with that of the postmortem electrocution group.@*CONCLUSION@#The changes of HSP 70 mRNA and c-fos mRNA expression in skeletal muscle and cardiac muscle can be used as an indicator to distinguish antemortem from postmortem electrocution.

Polyglutamine expansion in Drosophila: thermal stress and Hsp70 as selective agents.

Repetitive DNA sequences that encode polyglutamine tracts are prone to expansion and cause highly deleterious phenotypes of neurodegeneration. Despite this tendency,polyglutamine tracts ("polyQs") are conserved features of eukaryotic genomes. PolyQs are the most frequent protein-coding homotypic repeat in insect genomes, and are found predominantly in genes encoding transcription factors conserved from Drosophila through human. Although highly conserved across species, polyQ lengths vary widely within species. In D. melanogaster, polyQs in 25 genes have more alleles and higher heterozygosity than all other poly-amino acid tracts. The heat shock protein Hsp70 is a principal suppressor of polyQ expansions and may play a key role in modulating the phenotypes of the alleles that encode them. Hsp70 also promotes tolerance of natural thermal stress in Drosophila and diverse organisms,a role which may deplete the chaperone from buffering against polyQ toxicity. Thus in stressful environments, natural selection against long polyQ alleles more prone to expansion and deleterious phenotypes may be more effective. This hypothesis can be tested by measuring the phenotypic interactions between Hsp70 and polyQ transgenes in D. melanogaster undergoing natural thermal stress, an approach which integrates comparative genomics with experimental and ecological genetics.

Release of heat shock protein 70 (Hsp70) and the effects of extracellular Hsp70 on matric metalloproteinase-9 expression in human monocytic U937 cells

Heat shock protein 70 (Hsp70) release and its effects on pro-inflammatory cytokine production have been controversial. In this study, we investigated whether Hsp70 could be released from monocytes and activates matrix metalloproteinase-9 (MMP-9) gene expression. Hsp70 overexpression in human monocytic cell line U937 was found to increase PMA- induced MMP-9 expression and enhance cell motility. Hsp70 cDNA transfectants released Hsp70 protein into culture supernatants, and a part of released Hsp70 subsequently was bound to the surface of U937 cells. Addition of culture medium containing the extracelluar Hsp70 led to an increase not only in proMMP-9 secretion, but also the invasiveness of U937 cells through Matrigel or human umbilical vascular endothelial cells (HUVEC) in vitro. Immunodepletion of Hsp70 abolished its effect on MMP-9 expression. The released Hsp70 activated nuclear factor kappa B (NF-kappa B) and activating protein-1 (AP-1), which led to the activation of MMP-9 transcription. Taken together, these results suggest that extracellular Hsp70 induces the expression of MMP-9 gene through activation of NF-kappa B and AP-1.