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Cardiology Research, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas 77030
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ABSTRACT |
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 TOP
 ABSTRACT
 INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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Heat-shock proteins (HSPs) are an important family of
endogenous protective proteins, which increase in response to
myocardial ischemia and other stresses. Overexpression of HSP72
is cardioprotective. We were interested in the regulation of heat-shock
factor (HSF), the transcription factor for HSP genes. Previously we
have observed that the inflammatory cytokine tumor necrosis factor-
increases HSP72 levels and postulated that dexamethasone might effect
the heat shock response. In the adult rat cardiac myocyte we found that
treatment with either low (10 µM)- or high (100 µM)-dose dexamethasone activated HSF by 2-6 h as determined by gel shift assay without evidence of cytotoxicity. Although HSF activation is a
key step in expression of HSP72, this may not result in an increase in
HSP72. We found that 10 µM dexamethasone increased HSP72 38%, and
100 µM dexamethasone increased HSP72 62% (P < 0.05). HSP27
and HSP60 were unchanged. The selective increase in HSP72 was
associated with protection of the cardiac myocytes from hypoxia and
reoxygenation. We conclude that dexamethasone is a novel inducer of the
heat shock response.
glucocorticoids; heat-shock factor; ischemia
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INTRODUCTION |
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TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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HEAT-SHOCK PROTEINS (HSPs) are an important family of endogenous protective proteins, which increase in response to a wide variety of stresses (5, 15, 36, 43). These proteins have specificity of function and are found in different locations within the cell. HSP70 has been the focus of cardiac HSP research. There are at least two forms of HSP70 in mammalian cells: HSC (heat-shock constitutive)-70, a protein expressed at high levels in normal cells and involved in many of the chaperon and protein-folding functions of HSP70 and HSP72, expressed at low levels in normal tissue and rapidly induced in response to stress. In the heart HSP72 is induced by ischemia (16). Heat pretreatment to induce the heat-shock response reduces infarct size. Overexpression of HSP72 in various settings, including an embryonic cardiac cell line and transgenic mice, will protect these cells and tissues against various forms of stress (12, 22, 24, 32, 33). Previously we have observed that blocking the endogenous increase in HSP72 by antisense to HSP72 genes increased susceptibility to hypoxia and reoxygenation in isolated adult feline cardiocytes (29). Overexpression of HSP60 in conjunction with HSP10 is protective (20). Likewise, increased expression of HSP27 is protective against cardiac injury (23). Thus the HSPs have cardioprotective properties.
HSP synthesis is controlled by a specific family of transcription factors, heat-shock factors (HSFs), of which four have been identified but only two of these have been shown to be important to date (25, 26, 35). The primary HSF involved in regulation of expression of HSPs is HSF-1. Both heat and hypoxia activate HSF-1, which is present in the cytoplasm in an inactive form as a monomer. With stress trimerization occurs as well as phosphorylation. HSF-1 migrates to nucleus where it binds to the heat-shock element (HSE), which is present in the promoter of the stress response gene, initiating HSP transcription and synthesis. HSF-2 has been shown only to activate HSP transcription in an erythroleukemia line (37, 38).
We were interested in upregulating HSP expression by a less noxious
means than heat shock, which requires temperatures of 42°C or
higher. Previously, we have observed that tumor necrosis factor-
cytokine associated with inflammatory pathways increases HSP72 levels
in the absence of cellular injury (27, 28). We postulated that the
anti-inflammatory glucocorticoid steroids would influence activation of
HSF. In the present study, we report activation of HSF-1 by
dexamethasone at medically relevant concentrations in isolated adult
rat cardiac myocytes. Activation of HSF by dexamethasone represents a
novel pathway of HSP regulation that is independent of any evidence of
cell injury. The activation of HSF-1 is accompanied by an increase in
HSP72 but not HSP27 or HSP60. Pretreatment with dexamethasone followed
by hypoxia and reoxygenation protected cardiac myocytes from injury
compared with controls. This is to our knowledge the first report of
activation of the heat shock response by glucocorticoid hormones.
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METHODS |
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TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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Isolation of adult rat cardiac myocytes. Adult rat cardiac myocytes were isolated from 3- to 4-mo-old male Sprague-Dawley rats weighing 250-300 g according to a method described by Ford and Rovetto (10) with modification. Briefly, hearts were removed from rats following anesthesia with a combination of ketamine, xylazine, and acepromazine, and immersed in ice-cold heparin-Joklik A buffer [modified MEM/Joklik (GIBCO; Grand Island, NY), 60 mM taurine, 20 mM creatine, 5 mM HEPES, 0.1% BSA, 1 IU heparin/ml, pH 7.4]. After a 3-min perfusion on a Langendorff apparatus with heparin-Joklik A to remove any blood, the perfusion solution was switched to Joklik A with 0.6 mg/ml collagenase (collagenase type 2, Worthington Biochemical; Lakewood, NJ). After perfusion with collagenase, the hearts were minced and digested for 5 min in a shaking water bath at 37°C. This step was repeated twice to achieve complete digestion. The cell suspension was filtered and washed twice with Joklik A buffer, and the myocytes were transferred to the top of a 6% BSA gradient to increase the percent yield of rod-shaped cells. To reintroduce calcium, 100 mM CaCl2 was added to a final 1,000 µM calcium concentration in five steps with 5-min incubations. The cardiac myocytes were resuspended in medium 199 (M199) supplemented with 100 U penicillin, 100 µg streptomycin, 20 µl human serum albumin, 5 µg insulin, and 5 µg transferrin per milliliter and transferred to a cell culture flask for 2 h in an incubator at 37°C. After this differential plating step to remove fibroblasts, the cells were plated on laminin-coated dishes. This procedure yielded on average 70% rod-shaped cardiac myocytes. In pilot studies, staining with anti-mf20 antibody showed these cells were over 97% cardiac myocytes.
The animal protocol was approved by the Baylor College of Medicine Animal Research committee in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals [DHEW Publication No. (NIH) 85-23, Revised 1985, Office of Science and Health Reports, DRR/NIH, Bethesda, MD 20205].
Cardiac myocyte culture and dexamethasone treatment. Freshly
isolated cardiac myocytes were cultured in M199 (GIBCO) in petri dishes
precoated with 0.2% laminin (GIBCO) at 37°C in a humidified incubator with 5% CO2-95% air. When the cells became
adherent to the dishes (after 2-4 h of culture), the medium was
exchanged for fresh M199 medium containing either 10 or 100 µM
dexamethasone (Sigma; St Louis, MO), or equal volume of diluent. At 2, 4, and 6 h of treatment, samples were collected for gel mobility shift assays. After 10 h of treatment, either samples were collected for
Western analysis for HSP levels or the medium was changed and the cells
were subjected to hypoxia. The time line for this and subsequent
experimental manipulations are summarized in Fig. 1.
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Gel shift. For the gel mobility shift assay, we used
5'-CTAGAAGCTTCTAGAAGCTTCT-AG-3' as our consensus HSE, and
end-labeled with [
-32P]ATP. Otherwise, our
methods were as described by Benjamin et al. (3, 4). Because HSF is
normally present in the cell in an inactive form, we were able to use
whole cell lysates for our studies. Supershift studies were carried out
using a mouse monoclonal anti-HSF-1 (Affinity Bioreagents) and
anti-HSF-2 (the generous gift of R. Morimoto, Northwestern University).
The sample-HSE mixes were incubated with antibody at 1:5 and 1:10
dilutions for 30 min. For cold compete experiments, the samples were
incubated with a 50-fold molar excess of cold HSE for 15 min before the addition of labeled HSE. Images were collected using a PhosphoImager (Molecular Dynamics; Sunnyvale, CA)
Western blot analysis. Western blotting was performed as
previously described (17). Briefly, the cells were washed twice with
PBS and solubilized by scraping into ice-cold RIPA buffer (pH 7.4, 50 mM Tris, 150 mM NaCl, 2.5 mg/ml deoxycholic acid, 1 mM EGTA, 10 µl/ml
Nonidet P-40) supplemented with protease inhibitors (2.5 µg/ml
antipain, 2.5 µg/ml leupeptin, 1.75 µg/ml pepstatin A, 0.95 µg/ml
aprotinin, 2.5 mM phenylmethylsulfonyl fluoride) and sonicated. Protein
concentrations were determined with a bicinchoninic acid assay
(Pierce). Samples were stored at 
80°C until analyzed. The
antibodies to HSPs were purchased from StressGen (Victoria, Canada),
including rabbit polyclonal antibody to HSP72 protein (1:5,000
dilution), mouse monoclonal antibody to HSP60 protein (1:70,000
dilution), and rabbit polyclonal antibody to HSP27 protein (1:5,000
dilution). The mouse monoclonal antibody to -actin was purchased
from Sigma (1:1,000 dilution). Anti-HSP72 and anti-HSP27 were incubated
with anti-rabbit IgG-horseradish peroxidase (HRP) at 1:2,000 (Amersham;
Arlington Heights, IL). Anti-HSP60 and anti--actin were
developed with anti-mouse IgG-HRP at 1:1,000 (Amersham). Blots were
washed and developed using a chemiluminescent system (ECL, Amersham).
The films were scanned for densitometric analysis (SigmaGel, Jandel;
San Rafael, CA).
Hypoxia Studies
After dexamethasone treatment the medium was changed to DMEM base (no glucose, glutamine, or phenol red to prevent switching to glycolysis) and the cells were subjected to hypoxia for 4 h as previously described (29). Briefly, cells were exposed to 90% nitrogen-10% CO2 in a specially designed chamber (Billups-Rothenberg; Del Mar, CA). The dissolved oxygen with this system is 30 to 35 torr (PO2) with hypoxia, with a baseline of 140 torr during normoxia as previously reported (29).Indexes of injury. Ratio of live to dead cells, lactate dehydrogenase (LDH) levels, and C,N-diphenyl-N-4,5-dimethylthiazol-2-yltetrazolium chloride (MTT) were measured as previously described (29). Briefly, LDH levels were measured on medium samples using a colorimetric assay (Sigma) measuring the conversion of pyruvic acid to lactic acid by LDH. Mitochondrial function was determined using MTT. Tetrazolium salts are reduced by the respiratory chain; in the reduced state MTT turns blue, which can be quantified using a spectrophotometer. MTT is reduced in both the early and late portions of the respiratory chain, so assessment of its reduction allows evaluation of the entire respiratory chain. For our purposes cells were grown in 96-well microtiter plates (Falcon, Becton Dickinson; Franklin Lakes, NJ) coated with 0.2% laminin. A second plate containing serial dilutions of normoxic myocytes was used as a reference standard curve for mitochondrial function. After hypoxia the cells were returned to M199, 20 µl/well of MTT stock (5 mg/ml in PBS) added, and the cells returned to the incubator. SDS (10%, pH 7.2) was added after 4 h of incubation with MTT, the cells were incubated overnight, and optical density was measured with a microtiter plate reader at 600 nm (Molecular Devices). The optical density for each well was compared against the standard curve derived from the normoxic control serial dilution of cells, and the number of cells obtained from the standard curve was divided by the number originally plated to give percent uptake of MTT.
The ratio of live to dead cells, a simple index of cell viability, was determined by counting a minimum of 60 cells per plate after incubating the cells for 30 min with 1.05 µmol/l calcein-acetoxymethyl ester (AM) and 4.0 µmol/l ethidium homodimer (Molecular Probes; Eugene, OR) in M199. The cells were then viewed under ultraviolet light. Live cells take up the calcein-AM and are stained green, whereas dead and dying cells take up the ethidium homodimer and are stained red. Cells were scored as live or dead by an investigator blinded to treatment group.
Statistics and Data Analysis
All results are reported as means ± SE. Results represent the mean of three or more experiments with multiple data determinations in each experiment. Data were compared by one-way ANOVA followed by a Student-Newman-Keuls test. Data comparing normalized values with control values were compared with an ANOVA on ranks (Kruskal-Wallis) followed by a Dunn's test; if data samples passed test of normality and of equal variance, one-way ANOVA was performed. All statistical analysis was performed with SigmaStat (Jandel). A value of P < 0.05 was considered significant.| |
RESULTS |
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TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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Activation of HSF by Dexamethasone
Activation of HSF was observed with both 10 and 100 µM dexamethasone as shown in Fig. 2. This activation was seen as early as 2 h after treatment was started (data not shown) and persisted through 4 and 6 h. Cold competition with unlabeled probe showed the observed gel shift changes to be specific (Fig. 2A). The addition of antibodies to HSF-1 and HSF-2 showed a supershift only with anti-HSF-1, indicating that it is HSF-1 that is activated by dexamethasone treatment (Fig. 2B). As shown below, neither dose of dexamethasone was associated with any evidence of injury as assessed by three different measurements: LDH release, ratios of live to dead cells, and MTT uptake.
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Effect of Dexamethasone on HSP Levels
HSP72 expression. Western blot analysis showed that after 10 h of treatment with dexamethasone HSP72 increased 38 (P < 0.05) and 62% (P < 0.05) with 10 and 100 µM dexamethasone treatment, respectively, compared with the controls (Fig. 3). Levels of-actin were unchanged.
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Expression of HSP60 and HSP27. HSP60 and HSP27 levels were
examined by Western blotting on the same samples as for HSP72. There
was no change in levels of either HSP60 or HSP27 after dexamethasone treatment (Fig. 4).
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Hypoxia and Reoxygenation
To determine whether upregulation of HSP72 by dexamethasone pretreatment protected the cardiac myocytes, a series of hypoxia and reoxygenation experiments were performed. Pilot experiments were done to define the effect of hypoxia on the isolated adult rat cardiac myocytes. We selected 4 h of hypoxia followed by 4 h of reoxygenation to injure the cells. After pretreatment with 10 or 100 µM dexamethasone for 10 h, the medium was changed to DMEM base and the cells were subjected to 4 h of hypoxia followed by 4 h reoxygenation before assessment of cell injury. All samples for analysis of control, hypoxia, and reoxygenation were collected at the end of the 4-h reoxygenation period.LDH levels. LDH levels were measured in the medium. During
normoxia dexamethasone-treated cells had similar LDH levels in the
medium as untreated cells. As shown in Fig.
5, the LDH medium levels with hypoxia in
the 100 µM dexamethasone-treated cells were unchanged compared with
all groups of normoxic cells. LDH medium levels were less in the 10 µM cells than in the control cells following hypoxia, but this
difference was not significant. Both control hypoxia and reoxygenation
and 10 µM dexamethasone hypoxia and reoxygenation groups had
significantly increased LDH medium levels compared with normoxia. After
hypoxia and reoxygenation the level of LDH was 1.86 ± 0.16 U/µg
protein in controls, 1.65 ± 0.16 U/µg protein in 10 µM
dexamethasone-treated cells, and 1.32 ± 0.11 U/µg protein in 100 µM dexamethasone-treated cells. LDH medium levels were 1.02 ± 0.07 U/µg protein in untreated normoxia control cells [P < 0.05 vs. hypoxic controls and 10 µM dexamethasone, P = not
significant (ns) vs. 100 µM dexamethasone].
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Live/dead assay. The live/dead assay showed no difference
between dexamethasone-treated cells and controls in the absence of
hypoxia. After hypoxia, there was higher viability in both 10 and 100 µM dexamethasone-treated cells compared with control following
hypoxia. The viability in untreated hypoxia cells was 35.59 ± 4.47% (P < 0.05 vs. normoxia), 57.59 ± 7.61%
(P < 0.05 vs. control hypoxia-treated cells) in 10 µM
dexamethasone-treated hypoxia cells, and 67.79 ± 5.21%
(P = ns vs. normoxia) in 100 µM dexamethasone-treated
hypoxia cells (Fig. 6). Normoxic control cells had a viability of 84.18 ± 3.28%.
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MTT. Hypoxia and reoxygenation significantly reduced MTT
uptake; however, dexamethasone treatment had no effect on this measure of mitochondrial function in either normoxic or hypoxic groups (Fig.
7).
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DISCUSSION |
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TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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The findings in the present study demonstrate the activation of HSF-1 and increased expression of HSP72 in isolated adult rat cardiac myocytes treated with dexamethasone. No change was observed in levels of HSP27 or HSP60. There was no evidence of cellular injury from treatment with dexamethasone in the absence of hypoxia and reoxygenation, indicating that activation of HSF-1 in this setting is not mediated by cellular injury and protein denaturation. Pretreatment with dexamethasone resulted in resistance to hypoxia and reoxygenation injury as measured by the ratio of live to dead cells and LDH release. In contrast, the decreased mitochondrial function posthypoxia as measured by MTT uptake was not prevented by pretreatment with dexamethasone. This may reflect the lack of increase in HSP60, a mitochondrial HSP vs. HSP72, which is found in the cytoplasm and in the nucleus with stress.
Pretreatment with 100 µM dexamethasone increased HSP72 levels by 60%. Although this increase is less than that of heat shock, this change was associated with protection. The higher dose of dexamethasone was associated with a greater increase in HSP72 and more protection than the lower dose. The increase in HSP72 with dexamethasone is similar to the increase we observed with mild hypoxia (8 h) and reoxygenation in isolated adult feline cardiac myocytes (29). Blocking this increase in HSP72 after hypoxia and reoxygenation was associated with increased injury (29). Thus the modest increase in HSP72 associated with dexamethasone treatment has physiological importance.
Differential HSP Induction
Although HSF-1 is the transcription factor for multiple HSPs, only HSP72 increased. HSP72 appears to be one of the more responsive of the HSPs and may be more readily upregulated than some of the other HSPs. Whereas most studies have focused on a single HSP, some investigators have examined levels of several HSPs in response to a given stress and have found differential changes in HSPs (2, 21, 31, 42). In our own laboratory we have observed upregulation of HSP60 and HSP27 but not HSP72 in the setting of end-stage cardiomyopathy (18). Why these differences in HSP expression occur will be better understood as we learn more about the transcriptional and posttranscriptional regulation of HSPs in mammalian tissue.HSF-1 Activation
With dexamethasone, not only was HSF-1 activated, but activation was slower than the usual 10 or 15 min and was more sustained than the typical 1- or 2-h duration (3, 4, 13, 30). HSP72 is thought to be involved in turning off HSF-1 activation, and the very slow increase in HSP72 may be part of the reason for the prolonged activation of HSF-1 (1). However, the activation of HSF-1 by dexamethasone may be by a novel mechanism, and turn-off of activation may occur by a different mechanism.Hormones and HSP Induction
Glucocorticoids have a plethora of effects, including inhibition of lipid peroxidation, inhibition of formation of arachidonic acid products and modulation of neutrophil and endothelial function (19). Chronic glucocorticoid administration is known to alter protein metabolism (7, 8). Short-term glucocorticoid treatment blocks the inflammatory response. In patient studies, acute doses of dexamethasone and other glucocorticoids, in concentrations similar to the current study, reduced damage postcardioplegia, in spinal cord injury and in other acute injury states (9, 14, 39). Although these investigators did not examine HSP72, our results would suggest that HSP72 had been upregulated.In the last few years, considerable interest has developed in the
heat-shock response and myocardial protection. Multiple lines of
evidence have suggested a link between induction of the heat-shock
response and improved recovery of the myocardium from ischemic injury.
The known methods to induce the HSPs, such as heating, have deleterious
effects. As tumor necrosis factor-, a cytokine associated with
inflammatory pathways, increases HSP72 levels, we were interested in
whether the anti-inflammatory glucocorticoids altered HSF activation. A
number of reports have implicated hormones in regulation of HSP
expression. Vasopressin activated HSF-1, increased HSP72 mRNA, and was
associated with an increase in HSP72 in renal tubular cells (44).
Surgical stress and restraint stress both increased HSP72 levels in the
adrenal gland and the aorta but not in other organs (40, 42). Chronic
treatment with dexamethasone decreased the restraint-stimulated
increase in HSP72 (41). In healing wounds, chronic dexamethasone
treatment blocked the increase in HSP25, HSP72, and HSC70 and inhibited
fibroblast proliferation (11). The results of these previous
investigations suggest that long-term treatment with glucocorticoids
inhibits the stress response. The effect of short-term treatment,
addressed by the current study, has not been described previously.
In the late 1970s a number of investigators reported deleterious effects with repeated glucocorticoid usage in acute myocardial infarction (6, 34). Single-dose glucocorticoid therapy was not associated with adverse effects. Thus these previous adverse findings with multiple-dose glucocorticoid usage in acute myocardial infarction do not contraindicate the use of a single dose of dexamethasone to increase HSP expression in the setting of myocardial injury.
We conclude that dexamethasone activates HSF-1 and upregulates HSP72. This activation of HSF-1 is not preceded by cellular injury. These results suggest that a novel pathway of activation is involved. Further studies are needed to elucidate the interaction between glucocorticoids and the stress response.
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ACKNOWLEDGEMENTS |
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The authors thank Andrew Schafer for continued support and guidance.
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FOOTNOTES |
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This work was supported in part by the National Heart, Lung, and Blood Institute Grant HL-58515 (A. A. Knowlton).
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Address for reprint requests and other correspondence: A. A. Knowlton, Cardiology Research, 151C, VA Medical Center, 2002 Holcombe, Houston, TX 77030 (E-mail: annek{at}bcm.tmc.edu).
Received 29 June 1999; accepted in final form 19 October 1999.
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REFERENCES |
|---|
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TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
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|---|
1.
Abravaya, K.,
Myers M. P.,
Murphy S. P.,
and
Morimoto R. I.
The human heat shock protein HSP 70 interacts with HSF, the transcription factor that regulates heat shock gene expression.
Genes Dev.
6:
1153-1164,
1992
2.
Andres, J.,
Sharma H. S.,
Knöll R.,
Stahl J.,
Sassen L. M. A.,
Verdouw P. D.,
and
Schaper W.
Expression of heat shock proteins in the normal and stunned porcine myocardium.
Cardiovasc. Res.
27:
1421-1429,
1993
3.
Benjamin, I. J.,
Horie S.,
Greenberg M. L.,
Alpern R. J.,
and
Williams R. S.
Induction of stress proteins in cultured myogenic cells: molecular signals for the activation of heat shock transcription factor during ischemia.
J. Clin. Invest.
89:
1685-1689,
1992.
4.
Benjamin, I. J.,
Kroger B.,
and
Williams R. S.
Activation of the heat shock transcription factor by hypoxia in mammalian cells.
Proc. Natl. Acad. Sci. USA
87:
6263-6267,
1990
5.
Benjamin, I. J.,
and
McMillan D. R.
Stress (heat shock) proteins: molecular chaperones in cardiovascular biology and disease.
Circ. Res.
83:
117-132,
1998
6.
Bulkley, B. H.,
and
Roberts W. C.
Steroid therapy during acute myocardial infarction.
Am. J. Med.
56:
244-250,
1974[ISI][Medline].
7.
Clark, A. F.,
DeMartino G. N.,
and
Wildenthal K.
Effects of glucocorticoid treatment on cardiac protein synthesis and degradation.
Am. J. Physiol. Cell Physiol.
250:
C821-C827,
1986
8.
Czerwinski, S. M.,
Kurowski T. T.,
McKee E. E.,
Zak R.,
and
Hickson R. C.
Myosin heavy chain turnover during cardiac mass changes by glucocorticoids.
J. Appl. Physiol.
70:
300-305,
1991
9.
Diego, R. P.,
Mihalakakos P. J.,
Hexum T. D.,
and
Hill G. E.
Methylprednisolone and full-dose aprotinin reduce reperfusion injury after cardiopulmonary bypass.
J. Cardiothorac. Vasc. Anesth.
11:
29-31,
1997[ISI][Medline].
10.
Ford, D. A.,
and
Rovetto M. J.
Rat cardiac myocyte adenosine transport and metabolism.
Am. J. Physiol. Heart Circ. Physiol.
252:
H54-H63,
1987
11.
Gordon, C. B.,
Li D-G.,
Staggs C. A.,
Manson P.,
and
Udelsman R.
Impaired wound healing in Cushing's syndrome: the role of heat shock proteins.
Surgery
116:
1082-1087,
1994[ISI][Medline].
12.
Hutter, J. J.,
Mestril R.,
Tam E. K. W.,
Sievers R. E.,
Dillmann W. H.,
and
Wolfe C. L.
Overexpression of heat shock protein 72 in transgenic mice decreases infarct size in vivo.
Circulation
94:
1408-1411,
1996
13.
Iwaki, K.,
Chi S.,
Dillmann W. H.,
and
Mestril R.
Induction of HSP 70 in cultured rat neonatal cardiomyocytes by hypoxia and metabolic stress.
Circulation
87:
2023-2032,
1993
14.
Kanellopoulos, G. K.,
Kato H.,
Wu Y.,
Dougenis D.,
Mackey M.,
Hsu C. Y.,
and
Kouchoukos N. T.
Neuronal cell death in the ischemic spinal cord: the effect of methylprednisolone.
Ann. Thorac. Surg.
64:
1279-1285,
1997
15.
Knowlton, A. A.
The role of heat shock proteins in the heart.
J. Mol. Cell. Cardiol.
27:
121-131,
1995[ISI][Medline].
16.
Knowlton, A. A.,
Brecher P.,
and
Apstein C. S.
Rapid expression of heat shock protein in the rabbit after brief cardiac ischemia.
J. Clin. Invest.
87:
139-147,
1991.
17.
Knowlton, A. A.,
Eberli F. R.,
Brecher P.,
Romo G. M.,
Owen A.,
and
Apstein C. S.
A single myocardial stretch or decreased systolic fiber shortening stimulates the expression of heat shock protein 70 in the isolated, erythrocyte-perfused rabbit heart.
J. Clin. Invest.
88:
2018-2025,
1991.
18.
Knowlton, A. A.,
Kapadia S.,
Torre-Amione G.,
Durand J-B.,
Bies R.,
Young J.,
and
Mann D. L.
Differential expression of heat shock proteins in normal and failing human hearts.
J. Mol. Cell. Cardiol.
30:
811-818,
1998[ISI][Medline].
19.
Korompilias, A. V.,
Chen L.,
Seaber A. V.,
and
Urbaniak J. R.
Actions of glucocorticoidsteroids on ischemic-reperfused muscle and cutaneous tissue.
Microsurgery
17:
495-502,
1996[ISI][Medline].
20.
Lau, S.,
Patnaik N.,
Sayen R.,
and
Mestril R.
Simultaneous overexpression of two stress proteins in rat cardiomyocytes and myogenic cells confers protection against ischemia-induced injury.
Circulation
96:
2287-2294,
1997
21.
Marber, M. S.,
Latchmann D. S.,
Walker J. M.,
and
Yellon D. M.
Cardiac stress protein elevation 24 h after brief ischemia or heat stress is associated with resistance to myocardial infarction.
Circulation
88:
1264-1272,
1993
22.
Marber, M. S.,
Mestril R.,
Chi S-H.,
Sayen M. R.,
Yellon D. M.,
and
Dillmann W. H.
Overexpression of the rat inducible 70-kD heat stress protein in a transgenic mouse increases the resistance of the heart to ischemic injury.
J. Clin. Invest.
95:
1854-1860,
1995.
23.
Martin, J. L.,
Mestril R.,
Hilal-Dandan R.,
Brunton L. L.,
and
Dillmann W. H.
Small heat shock proteins and protection against ischemic injury in cardiac myocytes.
Circulation
96:
4343-4348,
1997
24.
Mestril, R.,
Chi S.,
Sayen R.,
O'Reilly K.,
and
Dillmann W. H.
Expression of inducible stress protein 70 in rat heart myogenic cells confers protection against simulated ischemia-induced injury.
J. Clin. Invest.
93:
759-767,
1994.
25.
Nakai, A.,
and
Morimoto R. I.
Characterization of a novel chicken heat shock transcription factor, heat shock factor 3, suggests a new regulatory pathway.
Mol. Cell. Biol.
13:
1983-1997,
1993
26.
Nakai, A.,
Tanabe M.,
Kawazoe Y.,
Inazawa J.,
Morimoto R. I.,
and
Nagata K.
HSF4, a new member of the human heat shock factor family which lacks properties of a transcriptional activator.
Mol. Cell. Biol.
17:
469-481,
1997[Abstract].
27.
Nakano, M.,
Knowlton A. A.,
Dibbs Z.,
and
Mann D. L.
Tumor necrosis factor- confers resistance to hypoxic injury in the adult mammalian cardiac myocyte.
Circulation
97:
1392-1400,
1998
28.
Nakano, M.,
Knowlton A. A.,
Yokoyama T.,
Lesslauer W.,
and
Mann D. L.
Tumor necrosis factor--induced expression of heat shock protein 72 in adult feline cardiac myocytes.
Am. J. Physiol. Heart Circ. Physiol.
270:
H1231-H1239,
1996
29.
Nakano, M.,
Mann D. L.,
and
Knowlton A. A.
Blocking the endogenous increase in HSP72 increases susceptibility to hypoxia and reoxygenation in isolated adult feline cardiocytes.
Circulation
95:
1523-1531,
1997
30.
Nishizawa, J.,
Nakai A.,
Higashi T.,
Tanabe M.,
Nomoto S.,
Matsuda K.,
Ban T.,
and
Nagata K.
Reperfusion causes significant activation of heat shock transcription factor 1 in ischemic rat heart.
Circulation
94:
2185-2192,
1996
31.
Ovelgonne, J. H.,
van Wijk R.,
Verkleij A. J.,
and
Post J. A.
Cultured neonatal rat heart cells can be preconditioned by ischemia, but not by heat shock. The role of stress proteins.
J. Mol. Cell. Cardiol.
28:
1617-1629,
1996[ISI][Medline].
32.
Plumier, J-C. L.,
Robertson H. A.,
and
Currie R. W.
Differential accumulation of mRNA for immediate early genes and heat shock genes after ischaemic injury.
J. Mol. Cell. Cardiol.
28:
1251-1260,
1996[ISI][Medline].
33.
Radford, N. B.,
Fina M.,
Benjamin I. J.,
Moreadith R. W.,
Graves K. H.,
Zhao P.,
Gavva S.,
Wiethoff A.,
Sherry A. D.,
Malloy C. R.,
and
Williams R. S.
Cardioprotective effects of 70-kDa heat shock protein in transgenic mice.
Proc. Natl. Acad. Sci. USA
93:
2339-2342,
1996
34.
Roberts, R.,
DeMello V.,
and
Sobel B. E.
Deleterious effects of methylprednisolone in patients with myocardial infarction.
Circulation
53, Suppl.:
I204-I206,
1976.
35.
Schuetz, T. J.,
Gallo G. J.,
Sheldon L.,
Tempst P.,
and
Kingston R. E.
Isolation of a cDNA forHSF2: evidence for two heat shock factor genes in humans.
Proc. Natl. Acad. Sci. USA
88:
6911-6915,
1991
36.
Sharma, H. S.,
and
Stahl J.
Role of small heat shock proteins in the cardiovascular system.
In: Heat Shock Proteins and the Cardiovascular System, edited by Knowlton A. A.. Norwell, MA: Kluwer, 1997, p. 127-158.
37.
Sistonen, L.,
Sarge K. D.,
Philips B.,
Abravaya K.,
and
Morimoto R. I.
Activation of heat shock factor 2 (HSF2) during hemin-induced differentiation of human erythroleukemia cells.
Mol. Cell. Biol.
12:
4104-4111,
1992
38.
Theodorakis, N. G.,
Zand D. J.,
Kotzbauer P. T.,
Williams G. T.,
and
Morimoto R. I.
Hemin-induced transcriptional activation of the HSP 70 gene during erythroid maturation in K562 cells is due to a heat shock factor-mediated stress response.
Mol. Cell. Biol.
9:
3166-3173,
1989
39.
Toft, P.,
Christiansen K.,
Tonnesen E.,
Nielsen C. H.,
and
Lillevang S.
Effect of methylprednisolone on the oxidative burst activity, adhesion molecules and clinical outcome following open heart surgery.
Scand. Cardiovasc. J.
31:
283-288,
1997[ISI][Medline].
40.
Udelsman, R.,
Blake M. J.,
and
Holbrook N. J.
Molecular response to surgical stress: specific and simultaneous heat shock protein induction in the adrenal cortex, aorta, and vena cava.
Surgery
110:
1125-1131,
1991[ISI][Medline].
41.
Udelsman, R.,
Blake M. J.,
Stagg C. A.,
and
Holbrook N. J.
Endocrine control of stress-induced heat shock protein 70 expression in vivo.
Surgery
115:
611-616,
1994[ISI][Medline].
42.
Udelsman, R.,
Blake M. J.,
Stagg C. A.,
Li D.,
Putney D. J.,
and
Holbrook N. J.
Vascular heat shock protein expression in response to stress: endocrine and autonomic regulation of this age-dependent response.
J. Clin. Invest.
91:
465-473,
1993.
43.
Welch, W. J.
The mammalian stress response: cell physiology and biochemistry of stress proteins.
In: Stress Proteins in Biology and Medicine, edited by Morimoto R. I.,
Tissières A.,
and Georgopoulos C.. Cold Spring Harbor, NY: Cold Spring Harbor Press, 1990, p. 223-278.
44.
Xu, Q.,
Ganju L.,
Fawcett T. W.,
and
Holbrook N. J.
Vasopressin-induced heat shock protein expression in renal tubular cells.
Lab. Invest.
74:
178-187,
1996[ISI][Medline].
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