Serum and lymphocyte levels of heat shock protein 70 in aging: a study in the normal Chinese population

Differential expression and regulation of HSP70 gene during growth phase in ruminants in response to heat stress

Heat shock proteins regulate the physiological mechanism of heat stress adaptation at cellular level. The present investigation was carried out to analyse the HSP70 gene regulation in various growth stage in ruminants in peripheral blood mononuclear cells (PBMCs). The relationship between HSP gene expression and thermotolerance in age-specific manner in ruminants has not been analysed. Therefore m-RNA HSP70 expression level was examined in different age groups of Jamunpari goat during hot climatic conditions. The experiment was carried out in 32 animals of Jamunapari goat belonging to the age groups of 3-months, 9-months, 12-months, and adults (2-3 year). Total RNA was isolated from peripheral blood mononuclear cells. The physiological response such as rectal temperature (RT), respiration rate (RR) and heart rate (HR) was used as indicator to heat stress. Temperature Humidity Index (THI) was used as an indicator of severity of environmental stress. The THI range varied from 82.00-92.08 during experimental period. The m-RNA HSP70 expression level at 9-month age of animals was up-regulated and significantly higher than other age groups. It was observed that the level of HSP70 transcripts in PBMCs was highest at 9-month age group, and age-related decline in HSP70 expression was observed in adult age. Based on the physiological response, the contrasting heat-stress phenotypes were recognised as heat stress susceptible (HSS) and heat stress tolerant (HST) individuals and the expression of m-RNA HSP70 was analysed at different ages in response to chronic heat stress. The differential mRNA expression of HSS individuals at 3 and 9-month of age showed the highest fold expression than HST. Age and phenotype had significant effect (p < 0.01) on the crossing point (CP) value. The m-RNA HSP70 gene expression in different age groups was correlated with heat stress tolerance and this could be used as biomarker for breeders to analyse the HSP response in -vivo in ruminants.

Role of heat shock protein and cytokine expression as markers of clinical outcomes with glutamine-supplemented parenteral nutrition in surgical ICU patients

BACKGROUND

Nutrients, such as glutamine (GLN), have been shown to effect levels of a family of protective proteins termed heat shock proteins (HSPs) in experimental and clinical critical illness. HSPs are believed to serve as extracellular inflammatory messengers and intracellular cytoprotective molecules. Extracellular HSP70 (eHSP70) has been termed a chaperokine due to ability to modulate the immune response. Altered levels of eHSP70 are associated with various disease states. Larger clinical trial data on GLN effect on eHSP expression and eHSP70's association with inflammatory mediators and clinical outcomes in critical illness are limited.

OBJECTIVE

Explore effect of longitudinal change in serum eHSP70, eHSP27 and inflammatory cytokine levels on clinical outcomes such as pneumonia and mortality in adult surgical intensive care unit (SICU) patients. Further, evaluate effect of parenteral nutrition (PN) supplemented with GLN (GLN-PN) versus GLN-free, standard PN (STD-PN) on serum eHSP70 and eHSP27 concentrations.

METHODS

Secondary observational analysis of a multicenter clinical trial in 150 adults after cardiac, vascular, or gastrointestinal surgery requiring PN support and SICU care conducted at five academic medical centers. Patients received isocaloric, isonitrogenous PN, with or without GLN dipeptide. Serum eHSP70 and eHSP27, interleukin-6 (IL-6), and 8 (IL-8) concentrations were analyzed in patient serum at baseline (prior to study PN) and over 28 days of follow up.

RESULTS

eHSP70 declined over time in survivors during 28 days follow-up, but non-survivors had significantly higher eHSP70 concentrations compared to survivors. In patients developing pneumonia, eHSP70, eHSP27, IL-8, and IL-6 were significantly elevated. Adjusted relative risk for hospital mortality was reduced 75% (RR = 0.25, p = 0.001) for SICU patients with a faster decline in eHSP70. The area under the receiver operating characteristic curve was 0.85 (95% CI: 0.76 to 0.94) for the final model suggesting excellent discrimination between SICU survivors and non-survivors. GLN-PN did not alter eHSP70 or eHSP27 serum concentrations over time compared to STD-PN.

CONCLUSION

Our results suggest that serum HSP70 concentration may be an important marker for severity of illness and likelihood of recovery in the SICU. GLN-supplemented-PN did not increase eHSP70.

Expression of cellular protective proteins SIRT1, HSP70 and SOD2 correlates with age and is significantly higher in NK cells of the oldest seniors

Background

NK cells are key effector lymphocytes of innate immunity provided with constitutive cytolytic activity, however, their role in human ageing is not entirely understood. The study aimed to analyze the expression of proteins involved in cellular stress response sirtuin 1 (SIRT1), heat shock protein 70 (HSP70) and manganese superoxide dismutase (SOD2) in non-stimulated NK cells of the oldest seniors (n = 25; aged over 85; mean age 88 years) and compare with NK cells of the old (n = 30; aged under 85; mean age 76 years) and the young (n = 32; mean age 21 years) to find potential relationships between the level of expression of these proteins in NK cells and longevity. The concentration of carbonyl groups and 8-isoprostanes in NK cell lysates reflecting the level of oxidative stress was also measured.

Results

The group of the oldest seniors differed from the other age groups by significantly higher percentage of NK cells expressing SIRT1, HSP70 and SOD2. The concentration of both carbonyl groups and 8-isoprostanes in NK cell extracts remained within the normal range in all age groups. The percentage of NK cells with the expression of, respectively, SIRT1, HSP70 and SOD2 correlated positively with age. Some correlations between expression levels of particular protective proteins SIRT1, HSP70 and SOD2 were observed in the study population.

Conclusions

The increased expression of cellular protective proteins SIRT1, HSP70 and SOD2 in NK cells of the oldest seniors seems to correspond to longevity and the observed correlations may suggest the involvement of these proteins in establishing NK cell homeostasis specific for healthy ageing process.

Effects of intracerebral hemorrhage and subsequent minimally invasive hematoma aspiration on expression of apoptosisrelated genes in rats

This study was to investigate the effects of intracerebral hemorrhage (ICH) and subsequent minimally invasive hematoma aspiration on the expression of apoptosis-related genes in rats. IV-collagenase was injected to the caudate nucleus of the rats to make ICH models. In the control group, 30 Sprague-Dawley (SD) rats were mock treated with saline instead of collagenase. Thirty SD rats with successful modeling were designated as the ICH group. Twenty-five SD rats with successful modeling and subsequent minimally invasive hematoma aspiration were designated as the therapy group. Expression of heat shock protein 70 (Hsp70), B-cell leukemia/lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax) in the brain tissues was detected by immunohistochemical assays. The expression of Hsp70, Bcl-2 and Bax in the control group was very low, and significantly increased in the ICH group and the therapy group. At each indicated time point, Hsp70 expression in the therapy group was significantly lower than that of the ICH group, Bax expression in the therapy group was significantly lower than that of the ICH group and Bcl-2 expression in the therapy group was significantly higher than that of the ICH group. These results suggest that ICH led to increased expression of apoptosis-related genes in the brain tissues. Hematoma aspiration up-regulated ICH induced Bcl-2 expression while down-regulated ICH induced Hsp70 and Bax expression.

Genetic variations of HSPA1A, the heat shock protein levels, and risk of atherosclerosis

HSPA1A is a serum and intracellular heat shock protein with antiapoptotic and antithrombotic properties. The present study examines the hypothesis that a decrease in the synthesis of this protein in relation to certain polymorphisms of the regulatory region of the HSPA1A gene can define a vascular disease risk phenotype. A randomly selected population was studied and stratified into groups according to the degree of vascular risk. After applying the Task Force Chart to 452 people, the subjects were divided into three groups: group 0 (no vascular risk factor or risk < 5%), n = 239; group 1 (moderate (10-20%) risk, with no clinical cardiovascular disease), n = 161; and group 2 (overt atherosclerosis), n = 52. Serum and intragranulocytic HSPA1A was quantified, and direct Sanger sequencing was performed in all subjects. An analysis was made of the association of two single nucleotide polymorphisms (db rs1008438 -110A/C and db rs1043618 +190 G/C) with circulating and intragranulocytic HSPA1A and the risk of atherosclerosis. The atherosclerotic subjects showed significantly lower circulating HSPA1A levels than the other groups, regardless of the genotype. The patients with CC genotype for both polymorphisms showed significantly lower intragranulocytic HSPA1A levels than the other genotypes. Serum HSPA1A concentrations could be proposed as a biomarker of cardiovascular disease. CC homozygosis for polymorphisms db rs1008438 and db rs1043618 is associated with a decrease in the intragranulocytic production of HSPA1A. Given the antiatherogenic functions of intracellular HSPA1A, the -110A and +190 G alleles could constitute potential genetic biomarkers of a less severe clinical phenotype for the risk of developing atherosclerosis.

Aging does not reduce heat shock protein 70 in the absence of chronic insulin resistance

Heat shock protein (HSP)70 decreases with age. Often aging is associated with coincident insulin resistance and higher blood glucose levels, which also associate with lower HSP70. We aimed to understand how these factors interrelate through a series of experiments using vervet monkeys (Chlorocebus aethiops sabaeous). Monkeys (n = 284, 4-25 years) fed low-fat diets showed no association of muscle HSP70 with age (r = .04, p = .53), but levels were highly heritable. Insulin resistance was induced in vervet monkeys with high-fat diets, and muscle biopsies were taken after 0.3 or 6 years. HSP70 levels were significantly greater after 0.3 years (+72%, p < .05) but were significantly lower following 6 years of high-fat diet (-77%, p < .05). Associations with glucose also switched from being positive (r = .44, p = .03) to strikingly negative (r = -.84, p < .001) with increasing insulin resistance. In conclusion, a low-fat diet may preserve tissue HSP70 and health with aging, whereas high-fat diets, insulin resistance, and genetic factors may be more important than age for determining HSP70 levels.

Involvement of extracellular Hsp72 in wear particle-mediated osteolysis

Wear particle-mediated osteolysis is one of the major problems affecting long-term survival of orthopaedic prostheses, frequently progressing to failure of fixation and revision surgery. Upon challenging with wear particles, macrophages and various other types of cells release soluble factors that stimulate the resorptive activity of osteoclasts and impair the function and activity of osteoblasts. Extracellular Hsp72 has been reported to activate macrophages and up-regulate pro-inflammatory cytokine production, although its role in osteolysis has not been established yet. The purpose of our study was to evaluate the involvement of this protein in the inflammatory response to wear particles that leads to periprosthetic osteolysis. To this end, we used interfacial tissues and blood samples from patients undergoing revision surgery due to aseptic loosening of cementless acetabular cups. Confocal microscopy indicated that Hsp72 co-localises with CD14(+) cells of interfacial tissues. Levels of Hsp72 in the culture media from periprosthetic membranes cultured ex vivo decreased along culture time and Hsp72 levels in sera from patients were lower and under the assay detection limit compared with those from age-matched control subjects. This suggests that interfacial tissues are not actively producing the protein but likely recruit it from peripheral circulation. Incubation of human macrophages with titanium (Ti) particles decreased the release of Hsp72 into culture media. Treatment with recombinant human Hsp72 enhanced considerably IL-6 levels in culture media which were not modified after macrophage co-stimulation with Ti particles, while pre-incubation with Hsp72 increased the Ti particle-induced TNF-α and IL-1β production. Altogether, these data indicate that extracellular Hsp72 amplifies the inflammatory response to wear debris by interacting with resident macrophages in periprosthetic tissues.

Protein profile changes during porcine oocyte aging and effects of caffeine on protein expression patterns

It has been shown that oocyte aging critically affects reproduction and development. By using proteomic tools, in the present study, changes in protein profiles during porcine oocyte aging and effects of caffeine on oocyte aging were investigated. By comparing control MII oocytes with aging MII oocytes, we identified 23 proteins that were up-regulated and 3 proteins that were down-regulated during the aging process. In caffeine-treated oocytes, 6 proteins were identified as up-regulated and 12 proteins were identified as down-regulated. A total of 38 differentially expressed proteins grouped into 5 regulation patterns were determined to relate to the aging and anti-aging process. By using the Gene Ontology system, we found that numerous functional gene products involved in metabolism, stress response, reactive oxygen species and cell cycle regulation were differentially expressed during the oocyte aging process, and most of these proteins are for the first time reported in our study, including 2 novel proteins. In addition, several proteins were found to be modified during oocyte aging. These data contribute new information that may be useful for future research on cellular aging and for improvement of oocyte quality.

Comparison of hemodynamic, biochemical and hematological parameters of healthy pregnant women in the third trimester of pregnancy and the active labor phase

BACKGROUND

Pregnancy is accompanied by several hemodynamic, biochemical and hematological changes which revert to normal values after labor. The mean values of these parameters have been reported for developed countries, but not for Mexican women. Furthermore, labor constitutes a stress situation, in which these factors may be altered. It is known that serologic increase of heat shock protein (Hsp) 70 is associated with abnormal pregnancies, presenting very low level in normal pregnant women. Nevertheless, there are no studies where these measurements are compared in healthy pregnant women at their third trimester of pregnancy (3TP) and the active labor phase (ActLP).

METHODS

Seventy five healthy Mexican pregnant women were included. Hemodynamic, biochemical and hematological parameters were obtained in all cases, and serum Hsp70 levels were measured in a sample of 15 women at 3TP and at ActLP.

RESULTS

Significant differences were found in most analysis performed and in Hsp70 concentration at 3TP as compared to ActLP, however all were within normal range in both conditions, supporting that only in pathological pregnancies Hsp70 is drastically increased.

CONCLUSION

Results obtained indicate that 3TP and ActLP have clinical similarities in normal pregnancies, therefore if abnormalities are found during 3TP, precautions should be taken before ActLP.

Circulating heat shock protein 70 in health, aging and disease

Background

Heat shock proteins (Hsp) are ubiquitously synthesised in virtually all species and it is hypothesised that they might have beneficial health effects. Recent studies have identified circulating Hsp as an important mediator in inflammation - the effects of low-grade inflammation in the aging process are overwhelming. While much is known about intracellular Hsp70, scant data exist on circulating Hsp70 in the aging context. Therefore, the objectives of this study were to investigate the effect of age and disease on circulating Hsp70 and, in particular, to evaluate the association between circulating Hsp70 and inflammatory parameters.

Results

Serum Hsp70, Interleukin (IL) -10, IL-6 and Tumor Necrosis Factor (TNF) alpha concentrations were determined in 90 hospitalised geriatric patients (aged 83 ± 6 years) and in 200 community-dwelling control subjects (100 elderly, aged 74 ± 5 years, and 100 young, aged 23 ± 3 years). In the community-dwelling elderly, serum Hsp70 and IL-10 concentrations were significantly lower and IL-6 was significantly higher when compared to healthy young control subjects. Elderly patients presenting inflammation (CRP serum levels ≥5 mg/L) showed significantly (p = 0.007) higher Hsp70 values; and Hsp70 correlated positively (p < 0.001) with IL-6 and CRP, but not with TNF-alpha or IL-10. A significant association was also noted between Hsp70 levels and the degree of dependency and cognitive decline in geriatric patients.

Conclusions

The present data provide new evidence that serum concentration of Hsp70 decreases with age in a normal population. Our study also shows that higher levels of Hsp70 are associated with inflammation and frailty in elderly patients.

Extracellular heat shock protein 70 (HSPA1A) and classical vascular risk factors in a general population

Atherosclerosis is a chronic inflammatory and autoimmune disease. Candidate molecules/autoantigens include heat shock proteins (HSPs); Hsp70 (HSPA1A) is one of the best studied HSPs. Various studies have shown a correlation between extracellular Hsp70 (eHsp70) and anti-Hsp70/anti-Hsp60 antibody concentration and development of atherosclerosis. A random sample of 456 people aged 40-60 (218 males, 234 females) was studied to investigate the prevalence of traditional vascular risk factors and eHsp70 and anti-Hsp70/anti-Hsp60 antibodies levels, according to the risk of vascular disease. Task Force Chart was applied for classification. Subjects were divided into three groups: G0 (with no vascular risk factor or a risk lower than 5%), n = 239; G1 (moderated 10-20% risk, who do not have established disease) n = 161; and G2 (established atherosclerosis disease) n = 52. eHsp70 and anti-Hsp70 were significantly lower in the atherosclerosis group (group 2) with respect to the other groups. Disease-free people showed the highest anti-Hsp60 concentration compared with the other two groups. A correlation has not been demonstrated between the concentrations of circulating Hsp70 (HSPA1A), anti-Hsp70, and anti-Hsp60 and classical vascular risk factors and C-reactive protein. Low levels of eHsp70 and anti-Hsp70 antibodies should be considered as candidate FRV. Simultaneous decrease of eHsp70 and anti-Hsp70 antibodies would be explained by circulating immune complex formation, and both could be proposed as biomarkers for the progression of atherosclerotic disease. Levels of circulating anti-Hsp60 antibodies may constitute a marker of inflammation in atherosclerosis.

Exogenous mammalian extracellular HSP70 reduces endotoxin manifestations at the cellular and organism levels

In this study, we checked whether HSP70 preparations of different origins are able to protect model animals (rats) from endotoxic shock and modify the response of myeloid cells to lipopolysaccharide (LPS) challenge. It was shown that HSP70 preparations can effectively protect organisms from endotoxic shock by strongly decreasing mortality and restoring both homeostasis and various hemodynamic characteristics. At the cellular level, HSP70 preparations significantly inhibit LPS-induced reactive oxygen species production in various myeloid cells and decrease NO expression in macrophages, which is enhanced after LPS priming. In parallel, HSP70 preconditioning partially normalizes neutrophil apoptosis, which is disturbed as a result of LPS stimulation. These results suggest that the antiseptic actions of HSP70 preparations are probably realized at the level of receptor membrane complexes of myeloid cells, which represent the major target of LPS action. Taken together, our findings show that extracellular mammalian HSP70 may play an important role in innate immunity modulation and stimulation of endogenous protective mechanisms, both at the cellular and organism levels, which make this protein a promising base for the development of efficient antiseptic drugs.

Increased circulating heat shock protein 70 levels in pregnant asthmatics

Asthma is one of the most common diseases complicating pregnancy and represents a risk factor for several maternal and perinatal complications. The natural history of asthma is known to change in pregnancy, but very few data are available in the terms of pathomechanism of this change during gestation. Circulating heat shock protein 70 (Hsp70) levels are decreased in healthy pregnancy, which might reflect physiological immunotolerance. The aim of our study was to determine the serum levels of Hsp70 in asthmatic women during gestation. Forty pregnant women with bronchial asthma and 40 healthy pregnant women matched for maternal and gestational age were involved in this case-control study. Serum Hsp70 levels were measured using the ELISA Kit of R&D Systems. Spirometry and oxygen saturation measurements were performed in asthmatic patients. In asthmatic pregnant women, an increase of serum Hsp70 levels was observed compared to healthy pregnant women (median (25-75 percentile): 0.44 ng/ml (0.36-0.53) versus 0.21 ng/ml (0-0.27), p < 0.001). Fetal birth weight of asthmatic mothers was significantly smaller than of healthy controls, but in the normal range (3,230 g (2,690-3,550) versus 3,550 g (3,450-3,775), p < 0.05). A statistically significant negative correlation between maternal age and serum Hsp70 concentrations (Spearman R = -0.48, p = 0.0018) and a significant positive correlation between gestational age and serum Hsp70 levels (Spearman R = 0.83, p < 0.001) were detected in healthy pregnant women. In conclusion, this study proves an elevation of circulating Hsp70 levels during asthmatic pregnancy compared to healthy pregnant women. However, further studies are warranted to determine the role of circulating Hsp70 in the pathogenesis of maternal and perinatal complications of asthma in pregnancy.

Circulating heat shock protein 70 (HSPA1A) in normal and pathological pregnancies

Heat shock proteins (Hsps) are ubiquitous and phylogenetically conserved molecules. They are usually considered to be intracellular proteins with molecular chaperone and cytoprotective functions. However, Hsp70 (HSPA1A) is present in the peripheral circulation of healthy nonpregnant and pregnant individuals. In normal pregnancy, circulating Hsp70 levels are decreased, and show a positive correlation with gestational age and an inverse correlation with maternal age. The capacity of extracellular Hsp70 to elicit innate and adaptive proinflammatory (Th1-type) immune responses might be harmful in pregnancy and may lead to the maternal immune rejection of the fetus. Decreased circulating Hsp70 level, consequently, may promote the maintenance of immunological tolerance to the fetus. Indeed, elevated circulating Hsp70 concentrations are associated with an increased risk of several pregnancy complications. Elevated Hsp70 levels in healthy pregnant women at term might also have an effect on the onset of labor. In preeclampsia, serum Hsp70 levels are increased, and reflect systemic inflammation, oxidative stress and hepatocellular injury. Furthermore, serum Hsp70 levels are significantly higher in patients with the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome) than in severely preeclamptic patients without HELLP syndrome. In HELLP syndrome, elevated serum Hsp70 level indicates tissue damage (hemolysis and hepatocellular injury) and disease severity. Increased circulating Hsp70 level may not only be a marker of these conditions, but might also play a role in their pathogenesis. Extracellular Hsp70 derived from stressed and damaged, necrotic cells can elicit a proinflammatory (Th1) immune response, which might be involved in the development of the maternal systemic inflammatory response and resultant endothelial damage in preeclampsia and HELLP syndrome. Circulating Hsp70 level is also elevated in preterm delivery high-risk patients, particularly in treatment-resistant cases, and may be a useful marker for evaluating the curative effects of treatment for preterm delivery. In addition, increased circulating Hsp70 levels observed in asthmatic pregnant patients might play a connecting role in the pathomechanism of asthmatic inflammation and obstetrical/perinatal complications. Nevertheless, a prospective study should be undertaken to determine whether elevated serum Hsp70 level precedes the development of any pregnancy complication, and thus can help to predict adverse maternal or perinatal pregnancy outcome. Moreover, the role of circulating Hsp70 in normal and pathological pregnancies is not fully known, and further studies are warranted to address this important issue.

Sage tea drinking improves lipid profile and antioxidant defences in humans

Salvia officinalis (common sage) is a plant with antidiabetic properties. A pilot trial (non-randomized crossover trial) with six healthy female volunteers (aged 40–50) was designed to evaluate the beneficial properties of sage tea consumption on blood glucose regulation, lipid profile and transaminase activity in humans. Effects of sage consumption on erythrocytes’ SOD and CAT activities and on Hsp70 expression in lymphocytes were also evaluated. Four weeks sage tea treatment had no effects on plasma glucose. An improvement in lipid profile was observed with lower plasma LDL cholesterol and total cholesterol levels as well as higher plasma HDL cholesterol levels during and two weeks after treatment. Sage tea also increased lymphocyte Hsp70 expression and erythrocyte SOD and CAT activities. No hepatotoxic effects or other adverse effects were observed.

Tissue-specific regulation and expression of heat shock proteins in type 2 diabetic monkeys

The chaperone protein heat shock protein (HSP) 70 has been shown to protect against obesity-associated insulin resistance. Induction of HSPs is thus considered an exciting therapeutic strategy for diabetes (DM). The aims of this study were to (1) determine HSP levels in plasma, hepatic, and pancreatic tissues of type 2 DM primates and (2) assess the relationship between chaperone proteins of the HSP family and cellular protection. We collected plasma from 24 type 2 DM and 25 normoglycemic control (CTL) cynomolgus macaques. A subset of DM monkeys had liver and pancreas samples available which were compared to a second group of CTL monkeys. We found that DM monkeys had 32% lower HSP70 in circulation which remained significant even after adjustment for the greater age and bodyweight of these monkeys (p < 0.001). The liver demonstrated a similar reductions in both HSP70 and 90 that was related to 50% lower levels of the transcription factor, heat shock factor 1 (HSF1; p = 0.03). Pancreatic tissue had the opposite expression pattern with significantly higher HSF1 (p = 0.004) and accordingly higher HSP70 and 90. Pancreas from DM monkeys had less nitrosative oxidation (p = 0.03) which was unaccounted for by superoxide dismutases and was negatively associated with HSP levels (r = -0.57, p = 0.009). HSF1/HSP deficiency exists in DM liver which may contribute to hepatic insulin resistance and this deficiency was reflected in lower circulating concentrations. Pancreas maintains HSP levels despite hyperglycemia, likely in an attempt to protect vulnerable beta cells from exocrine pancreatic damage and from stress associated with insulin hypersecretion.

The level of Hsp27 in lymphocytes is negatively associated with a higher risk of lung cancer

Heat shock proteins (Hsps) can protect cells, organs, and whole organisms against damage caused by abnormal environmental hazards. Some studies have reported that lymphocyte Hsps may serve as biomarkers for evaluating disease status and exposure to environmental stresses; however, few epidemiologic studies have examined the associations between lymphocyte Hsps levels and lung cancer risk. We examined lymphocyte levels of Hsp27 and Hsp70 in 263 lung cancer cases and age- and gender-matched cancer-free controls by flow cytometry. Multivariate logistic regression models were used to estimate the association between lymphocyte Hsps levels and lung cancer risk. Our results showed that Hsp27 levels were significantly lower in lung cancer cases than in controls (16.5 vs 17.8 mean fluorescence intensity, P < 0.001). This was not observed for Hsp70 levels. Further stratification analysis revealed that lymphocyte Hsp27 levels were negatively associated with lung cancer risk especially in males and heavy smokers. There was a statistical trend of low odd ratios (95% confidence intervals) and upper tertile levels of Hsp27 [1.000, 0.904 (0.566-1.444) and 0.382 (0.221-0.658, P (trend) = 0.001) in males and 1.000, 0.9207 (0.465-1.822) and 0.419 (0.195-0.897, P (trend) = 0.036) in heavy smokers] after adjustment for confounding factors. These results suggest that lower lymphocyte Hsp27 levels might be associated with an increased risk of lung cancer. Our findings need to be validated in a large prospective study.

Using lymphocyte and plasma Hsp70 as biomarkers for assessing coke oven exposure among steel workers

BACKGROUND

Hsp70, an early-response protein induced when organisms are confronted with simple or complicated environmental stresses, can act as either a cellular protector or a danger signal.

OBJECTIVES

The goal of this study was to evaluate levels of lymphocyte and/or plasma Hsp70 as biomarkers for assessing exposure response to complex coke oven emissions (COEs).

METHODS

We recruited 101 coke oven workers and determined levels of polycyclic aromatic hydrocarbon (PAH) exposure, urinary 1-hydroxypyrene (1-OHP), genotoxic damage by comet assay and micronuclei test, and other markers of damage, including plasma malondialdehyde (MDA) and lactate dehydrogenase (LDH). These were compared to levels of lymphocyte (intra-cellular) and plasma (extracellular) Hsp70 using Western blots and enzyme-linked immunosorbent assays (ELISA), respectively.

RESULTS

We observed a COEs-related dose-dependent increase in levels of DNA damage, micronuclei rate, MDA concentration, and LDH activity. Lymphocyte Hsp70 levels increased in the intermediate-exposure group (1.39 +/- 0.88) but decreased in the high-exposure group (1.10 +/- 0.55), compared with the low-exposure group. In contrast, plasma Hsp70 levels progressively increased as the dose of exposure increased. Negative correlations were seen between lymphocyte Hsp70 levels and olive tail moment and LDH activity in the intermediate- and high-exposure groups. However, we observed positive correlations between plasma Hsp70 levels and LDH activity in the low and intermediate groups.

CONCLUSIONS

In workers exposed to COEs, high lymphocyte Hsp70 levels may provide protection and high plasma Hsp70 levels may serve as a danger marker. Larger validation studies are needed to establish the utility of Hsp70 as a response marker.

Association of increased heat shock protein 70 levels in the lymphocyte with high risk of adverse pregnancy outcomes in early pregnancy: a nested case-control study

Studies suggest that heat shock proteins (Hsps), Hsp70 in particular, may play a role in embryogenesis and reproduction. As the first trimester is the critical period of human fetal development, we tested whether there is an association between Hsp70 expression in lymphocytes and adverse pregnancy outcomes (APOs) during that period. We measured lymphocyte Hsp70 levels by immunoblot in 55 pregnant women with APOs and 110 well-matched controls selected from 778 pregnant women in a nested case-control study. Multivariate logistic regression models were used to investigate the association between lymphocyte Hsp70 levels and risk of developing APOs. Our data showed that Hsp70 levels in women with APOs, especially those younger than 29 years old, were significantly higher than controls (193 vs 135 units, P < 0.001) and that the elevated Hsp70 levels were associated with a significantly increased risk of APOs (adjusted OR = 1.014; 95% CI = 1.008-1.020, P < 0.001). Our results also showed that the sensitivity, specificity, and positive and negative predictive values were 78%, 60%, 50%, and 85%, respectively, among these pregnant women. Adjusted ORs and 95% CI for the association between a Hsp70 value > 153 IOD and APOs were statistically significant (OR = 8.78, 95% CI = 2.79-27.64, P < 0.001). These results suggest that Hsp70 may play a role in the etiology of APOs. However, the underlying mechanisms for the elevation of Hsp70 in women with APOs and whether Hsp70 can be applied as a clinical indicator of APOs warrant further investigations.

Heme oxygenase 1 expression in rat liver during ageing and ethanol intoxication

Heme oxygenase 1 (HO-1) expression is recognized as a marker of cellular response to oxidative stress; since ageing is believed to be related to oxidative "wear and tear", HO-1 may represent a candidate biomarker of ageing. In our study, the hepatic expression of HO-1 mRNA, evaluated by RT-PCR in 2.5-24 month-old rats, was higher at 6 months than at 2.5 months of age, but thereafter increased no further: on the contrary, a declining trend was observed. However, while 2.5 month-old rats responded to acute ethanol intoxication by displaying increased expression of liver HO-1 mRNA, and 6 month-old rats exhibited a mild response, 18 month-old rats did not show any response; this phenomenon suggests that during development and ageing the transcriptional response to oxidative stress decreases. In our view, the finding that HO-1 expression did not increase progressively during ageing may be explained by a decreased transcriptional ability to respond to stress in older animals, rather than by a reduction in oxidative stress.

Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 +/- 1.7 years) and middle-aged (mean age = 56.3 +/- 4.7 years) subjects after 1 hour of heat shock at 42 degrees C. Genotype-specific HSR was measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible and inducible forms of Hsp70 decreased 1.3-fold (P < 0.001) and 1.4-fold (P < 0.001), respectively, in the monocytes with age. In the young subjects, a positive association was found between HSPA1L(T2437C) polymorphism and HSR. CC carriers had a significantly lower induction than TT carriers in both monocytes (P = 0.015) and lymphocytes (P = 0.044). This polymorphism, which is present in the coding region of HSPA1L gene, can affect the chaperoning function of Hsp70. These data consolidate our other observations that the CC genotype is unfavorable for human longevity and provide a functional explanation in terms of variations in HSR.

Serum heat shock protein 70 level as a biomarker of exceptional longevity

Heat shock proteins are highly conserved proteins that, when produced intracellularly, protect stress exposed cells. In contrast, extracellular heat shock protein 70 (Hsp70) has been shown to have both protective and deleterious effects. In this study, we assessed heat shock protein 70 for its potential role in human longevity. Because of the importance of HSP to disease processes, cellular protection, and inflammation, we hypothesized that: (1) Hsp70 levels in centenarians and centenarian offspring are different from controls and (2) alleles in genes associated with Hsp70 explain these differences. In this cross-sectional study, we assessed serum Hsp70 levels from participants enrolled in either the New England Centenarian Study (NECS) or the Longevity Genes Project (LGP): 87 centenarians (from LGP), 93 centenarian offspring (from NECS), and 126 controls (43 from NECS, 83 from LGP). We also examined genotypic and allelic frequencies of polymorphisms in HSP70-A1A and HSP70-A1B in 347 centenarians (266 from the NECS, 81 from the LGP), 260 NECS centenarian offspring, and 238 controls (NECS: 53 spousal controls and 106 septuagenarian offspring controls; LGP: 79 spousal controls). The adjusted mean serum Hsp70 levels (ng/mL) for the NECS centenarian offspring, LGP centenarians, LGP spousal controls, and NECS controls were 1.05, 1.13, 3.07, 6.93, respectively, suggesting that a low serum Hsp70 level is associated with longevity; however, no genetic associations were found with two SNPs within two hsp70 genes.

Increased resistance of lipofuscin-loaded prematurely senescent fibroblasts to starvation-induced programmed cell death

Alterations of cellular structures often found in ageing cells is mainly the result of production of reactive oxygen species and a consequence of aerobic life. Both oxidative stress and decreased degradative capacity of lysosomal system cause accumulation of intralysosomal age-related pigment called lipofuscin. To investigate the influence of lipofuscin on cell function, we compared survival of lipofuscin-loaded and control human fibroblasts following complete starvation induced by exposure to phosphate-buffered saline (PBS). Starving of control fibroblasts resulted in lysosomal alkalinisation, relocation of cathepsin D to the cytosol, caspase-3 activation and, finally, cell death, which became evident 72 h after the start of exposure to PBS. Increase of lysosomal pH was significantly less prominent in lipofuscin-loaded cells than in controls and was accompanied neither by leakage of cathepsin D nor by caspase-3 activation even 96 h after the initiation of starvation. Suppression of autophagy by 3-methyladenine (3-MA) accelerated cell death, while inhibition of cathepsin D delayed it, implying an important role of autophagy in cell survival during starvation and showing the involvement of lysosomes in starvation-induced cell death. Disturbed apoptotic response found in lipofuscin-loaded cells can be interpreted as an example of hormesis--an adaptation to low doses of otherwise harmful agents, in this case of lipofuscin, which has a protective effect at moderate amounts but becomes toxic at large quantities.

Antibodies against heat shock proteins in environmental stresses and diseases: friend or foe?

Heat shock proteins (Hsps) can be found in two forms, intracellular and extracellular. The intracellular Hsps are induced as a result of stress and have been found to be cytoprotective in many instances due to their chaperone functions in protein folding and in protein degradation. The origin and role of extracellular Hsps is less clear. Although they were suspected originally to be released from damaged cells (necrosis), their presence in most normal individuals rather suggests that they have regulatory functions in circulation. As immunodominant molecules, Hsps can stimulate the immune system, leading to the production of autoantibodies recognizing epitopes shared by microbial and human Hsps. Thus, extracellular Hsps can influence the inflammatory response as evidenced by the production of inflammatory cytokines. Antibodies to Hsps have been found under normal conditions but seem to be increased in certain stresses and diseases. Such antibodies could regulate the inflammatory response positively or negatively. Here, we review the literature on the findings of antibodies to Hsps in situations of environmental or occupational stress and in a number of diseases and discuss their possible significance for the diagnosis, prognosis, or pathogenesis of these diseases.

Chronic antioxidant enzyme mimetic treatment differentially modulates hyperthermia-induced liver HSP70 expression with aging

One postulated mechanism for the reduction in stress tolerance with aging is a decline in the regulation of stress-responsive genes, such as inducible heat shock protein 72 (HSP70). Increased levels of oxidative stress are also associated with aging, but it is unclear what impact a prooxidant environment might have on HSP70 gene expression. This study utilized a superoxide dismutase/catalase mimetic (Eukarion-189) to evaluate the impact of a change in redox environment on age-related HSP70 responses to a physiologically relevant heat challenge. Results demonstrate that liver HSP70 mRNA and protein levels are reduced in old compared with young rats at selected time points over a 48-h recovery period following a heat-stress protocol. While chronic systemic administration of Eukarion-189 suppressed hyperthermia-induced liver HSP70 mRNA expression in both age groups, HSP70 protein accumulation was blunted in old rats but not in their young counterparts. These data suggest that a decline in HSP70 mRNA levels may be responsible for the reduction in HSP70 protein observed in old animals after heat stress. Furthermore, improvements in redox status were associated with reduced HSP70 mRNA levels in both young and old rats, but differential effects were manifested on protein expression, suggesting that HSP70 induction is differentially regulated with aging. These findings highlight the integrated mechanisms of stress protein regulation in eukaryotic organisms responding to environmental stress, which likely involve interactions between a wide range of cellular signals.

Association of hsp70-2 and hsp-hom gene polymorphisms with risk of acute high-altitude illness in a Chinese population

High-altitude illness (HAI) is a potentially fatal condition involving genetic and environmental components. Accumulated experimental evidence suggests that heat shock proteins (Hsps), especially HSP70, can protect cells and organs against different types of damage. We investigated whether genetic variation in constitutive and inducible hsp70 genes could be associated with risk of HAI. The association between polymorphisms of the HSP70 family genes and risk of HAI was determined in 56 patients with HAI and in 100 matched controls by genotyping for the polymorphisms +190 G/C, +1267 A/G, 2437 G/C in the hsp70-1, hsp70-2, and hsp70-hom genes by using polymerase chain reaction-restriction fragment length polymorphism. The data showed that there was no statistically significant difference in the genotype and allele distributions of hsp70-1, in hsp70-2 allele and hsp70-2 A/A and A/B genotypes, and in allele distribution of hsp70-hom among patients with HAI and controls (chi2 test, P > 0.05). However, there was a significantly higher frequency of hsp70-2 B/B and hsp70-hom A/A and B/B genotypes and a significantly lower frequency of the hsp70-hom A/B genotype in the HAI patients compared with the controls (P < 0.05 for all). The risk associated with the hsp70-2 B/B and hsp70-hom A/A, A/B, and B/B genotypes were 4.017 (95% CI = 1.496-10.781; P = 0.004), 2.434 (95% CI = 1.184-5.003; P = 0.012), 0.299 (95% CI = 0.148-0.602, P = 0.001), and 5.880 (95% CI =1.145-30.196, P = 0.026), respectively. Our results suggest that individuals with hsp70-2 B/B and hsp70-hom A/B and B/B genotypes may be more susceptible to HAI, whereas those with hsp70-hom A/B genotype may be tolerant to HAI. Further studies in individuals of different age and sex are warranted to elucidate the underlying mechanisms of this association and the possible functions of different genotypes of hsp70-2 and hsp70-hom under hypoxic stress.