HSP70 expression in dentigerous cyst, odontogenic keratocyst, and ameloblastoma.

Heat shock proteins (HSPs) work as molecular chaperones that can assist cells to deal with stressful situations. Members of the HSP70 family can regulate cell growth and transformation and are involved in the maintenance of cellular homeostasis. In view of the distinct clinical behavior of odontogenic lesions, the objective of the present study was to investigate the immunohistochemical expression of HSP70 in these lesions. In this study, 70 formalin-fixed paraffin-embedded tissue blocks of odontogenic lesion-16 unicystic ameloblastomas (UAs), 17 solid ameloblastomas (SAs), 18 odontogenic keratocysts (OKCs), and 19 dentigerous cysts (DCs)-were reviewed by immunohistochemistry for HSP70 staining. In this study, HSP70 immunostaining was evident in all groups of the specimen. Mean percentage of HSP70 staining in SAs (84.2 ± 11.3) and OKCs (83.4 ± 6.8) were significantly higher than UAs (64.4 ± 9.8) and DCs (12.6 ± 10.2) (p = 0.00). But, there was no statistically significant difference between HSP70 expression in SAs and OKCs. The result of this study proposes that high expression rate of HSP70 has a role in the pathogenesis of ameloblastoma and OKC and is one of the reasons for the aggressive behavior of ameloblastoma and high recurrence role of OKC, reinforcing the classification of OKC as an odontogenic tumor.

Hsp25 and Hsp72 content in rat skeletal muscle following controlled shortening and lengthening contractions.

The cytoprotective proteins, Hsp25 and Hsp72, are increased in skeletal muscle after nondamaging, shortening contractions, but the temporal pattern of expression and stimulatory mechanisms remain unclear. Thus, we sought to define the in vivo temporal patterns of expression for Hsp25 and Hsp72 after 2 opposing contractions types. To do this, male Sprague-Dawley rats had 1 tibialis anterior (TA) muscle electrically stimulated (5 sets of 20 repetitions) while being either forcibly lengthened (LC) or shortened (SC). At 2, 8, 24, 48, 72, or 168 h after the contractions both the stimulated and the nonstimulated (contra-lateral control) TA muscles were removed and processed to examine muscle damage (hemotoxylin and eosin staining) and Hsp content (Western blot analyses). Cross-sections from TA muscles subjected to LCs showed muscle fibre damage at 8 h and thereafter. In contrast, no muscle fibre damage was observed at any time point following SCs. When normalized to contra-lateral controls, Hsp25 and Hsp72 content were significantly (P < 0.01) increased at 24 h (3.1- and 3.8-fold, respectively) and thereafter. There were no significant increases in Hsp25 or Hsp72 content at any time point following SC. These data suggest that LCs, but not SCs, result in Hsp accumulation and that the fibre/cellular damage sustained from LCs may be the stimulus for elevating Hsp content.

Exercise preconditioning protects against spinal cord injury in rats by upregulating neuronal and astroglial heat shock protein 72.

The heat shock protein 72 (HSP 72) is a universal marker of stress protein whose expression can be induced by physical exercise. Here we report that, in a localized model of spinal cord injury (SCI), exercised rats (given pre-SCI exercise) had significantly higher levels of neuronal and astroglial HSP 72, a lower functional deficit, fewer spinal cord contusions, and fewer apoptotic cells than did non-exercised rats. pSUPER plasmid expressing HSP 72 small interfering RNA (SiRNA-HSP 72) was injected into the injured spinal cords. In addition to reducing neuronal and astroglial HSP 72, the (SiRNA-HSP 72) significantly attenuated the beneficial effects of exercise preconditioning in reducing functional deficits as well as spinal cord contusion and apoptosis. Because exercise preconditioning induces increased neuronal and astroglial levels of HSP 72 in the gray matter of normal spinal cord tissue, exercise preconditioning promoted functional recovery in rats after SCI by upregulating neuronal and astroglial HSP 72 in the gray matter of the injured spinal cord. We reveal an important function of neuronal and astroglial HSP 72 in protecting neuronal and astroglial apoptosis in the injured spinal cord. We conclude that HSP 72-mediated exercise preconditioning is a promising strategy for facilitating functional recovery from SCI.

The effect of glutamine on cerebral ischaemic injury after cardiac arrest.

OBJECTIVES: The aim of this study is to investigate whether glutamine (GLN) enhances heat shock protein-25 (Hsp-25) and heat shock protein-72 (Hsp-72) expressions and attenuates cerebral ischaemic injury in rat cardiac arrest model. METHODS: Rats survived from cardiac arrest model were randomly assigned to CPR+GLN group (0.75 g/kg of alanyl-glutamine, n=6) or CPR group (same volume of 0.9% saline, n=6). Additional 6 rats were used for SHAM group. For the outcome measures, neurologic deficit score (NDS, 0-80) was checked at 24h and 72 h after cardiac arrest. At 72 h after cardiac arrest, rats were euthanised and the brain was harvested. Then, right hemisphere was used for cresyl-violet and TUNEL staining. Left hemisphere was used for Western blot analysis of phosphorylated heat shock factor-1 (p-HSF-1), Hsp-25, Hsp-72, and cleaved caspase-3. Kruskal-Wallis test and Mann-Whitney U post hoc test with Bonferroni correction were used for the analysis. RESULTS: Resuscitation variables were not different between CPR and CPR+GLN. NDS in CPR+GLN was higher than that in CPR (p<0.017) and lower than that in SHAM (p<0.017) at both 24h and 72 h. p-HSF-1, Hsp-25 and Hsp-72 expressions in CPR+GLN were significantly enhanced (p<0.017) than those in other groups. Cleaved caspase-3 expression in CPR was significantly higher (p<0.017) than in SHAM and CPR+GLN. Ischaemic and TUNEL-positive neurons were more frequently observed in CPR than in CPR+GLN. CONCLUSIONS: Glutamine attenuates cerebral ischaemic injury in cardiac arrest model of rats and this is associated with the enhancement of Hsp-25 and Hsp-72 expressions.

Alternate day calorie restriction improves systemic inflammation in a mouse model of sepsis induced by cecal ligation and puncture.

BACKGROUND: Calorie restriction (CR) exerts cytoprotective effects by up-regulating survival factors, such as mammalian target of rapamycin (mTOR), sirtuin, and peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α). These survival factors have well-established roles in attenuating the inflammatory response. However, it is unclear whether CR affects sepsis-related inflammation. The purpose of this study was to determine whether CR affects sepsis-induced inflammation in a cecal ligation and puncture (CLP)-induced mouse model of sepsis. METHODS: Male C57BL/6N mice underwent alternate day calorie restriction or normal feeding for 8 d before CLP-induced sepsis. After induction of sepsis, liver and lung histopathology and serum levels of cytokines and survival factors were assessed. RESULTS: Serum cytokine and high mobility group box protein 1 (HMGB1) levels were lower in animals that underwent alternate day calorie restriction compared with normally-fed mice after CLP. Alternate day calorie restriction also increased levels of sirtuin, PGC-1α, and mTOR. While 80% of mice in the CLP group died within 48 h after undergoing CLP, 50% of mice died in the ACR + CLP group (P < 0.05). CONCLUSION: Alternate day calorie restriction decreased mortality in a mouse model of sepsis. In addition to attenuated organ injury, a significant reduction in cytokine and HMGB1 levels was observed. These findings suggest that alternative day calorie restriction may reduce excessive inflammation.

Measuring Hsp72 (HSPA1A) by indirect sandwich ELISA.

The enzyme-linked immunosorbent assay (ELISA) is an immunological technique which is used to determine the presence or quantity of an antigen within a sample. ELISAs rely on the use of at least one antibody (Ab) specific for the antigen being measured. This antibody is covalently linked to an enzyme which is detected through the use of an enzymatic substrate, which can be colorimetric, fluorogenic, or chemiluminescent. The ELISA for Hsp72 described here is a typical indirect sandwich ELISA, which can be used for measuring Hsp72 from cellular/tissue extracts, tissue culture supernatant, and serum. Typically, a 96-well ELISA plate is coated with a specific antibody which captures Hsp72 from the sample, and another antibody specific for a different Hsp72 epitope is used to detect Hsp72. An enzyme-labelled species-specific antibody conjugate is then applied which is consequently detected using a colorimetric enzyme substrate. The quantity of Hsp72 present in the samples is interpolated using a standard curve of known amounts of pure Hsp72.

Research report: the effects of hyperbaric oxygen preconditioning on myocardial biomarkers of cardioprotection in patients having coronary artery bypass graft surgery.

We have previously conducted and reported on the primary endpoint of a clinical study which demonstrated that hyperbaric oxygen (HBO2) preconditioning consisting of two 30-minute intervals of 100% oxygen at 2.4 atmospheres absolute (ATA) prior to coronary artery bypass graft (CABG) surgery leads to an improvement in left ventricular stroke work (LVSW) 24 hours following CABG. In that study, 81 patients were randomized to treatment with HBO2 (HBO2; n = 41) or routine treatment (Control Group; n = 40) prior to surgery. The objective of this manuscript is to further report on the result of the exploratory secondary endpoints from that study, specifically the effects of HBO2 preconditioning on biomarkers of myocardial protection. Intraoperative right atrial biopsies were assessed, via an Enzyme Linked ImmunoSorbent Assay (ELISA), for the expression of eNOS and HSP72. In this study, no significant differences were observed between the groups with respect to the quantity of myocardial eNOS and HSP72. However, in the HBO2 Group, following ischemia and reperfusion, the quantities of myocardial eNOS and HSP72 were increased. This suggests that HBO2 preconditioning in this group of patients may be capable of inducing endogenous cardioprotection following ischemic reperfusion injury (IRI).

Characterization of polyamine homeostasis in l-ornithine-induced acute pancreatitis in rats.

OBJECTIVES: l-Ornithine is a precursor of polyamine synthesis that is essential for cell survival. In contrast, intraperitoneal (IP) administration of a large dose of l-ornithine results in death of pancreatic acinar cells in rats. We investigated changes in pancreatic and extrapancreatic polyamine homeostasis after injection of l-ornithine and tested the effects of the stable polyamine analogue methylspermidine (MeSpd) on l-ornithine-induced pancreatitis. METHODS: Male Wistar rats were injected IP with 3 g/kg l-ornithine and were untreated, pretreated, or treated with 50 mg/kg MeSpd IP. Rats were killed after 0 to 168 hours for determinations of polyamines and activities of ornithine decarboxylase and spermidine/spermine N(1)-acetyltransferase (SSAT). Pancreatitis severity was assessed by measuring standard laboratory and histological parameters. RESULTS: Injection of l-ornithine paradoxically induced pancreatic spermidine catabolism, possibly via activation of SSAT, after (>6 hours) appearance of the first histological signs of acute pancreatitis. Polyamine levels generally increased in the lung and liver with the exception of lung spermidine levels, which decreased. Methylspermidine did not influence polyamine levels and SSAT activity and did not ameliorate the severity of l-ornithine-induced pancreatitis. CONCLUSIONS: l-Ornithine-induced pancreatitis was associated with activation of pancreatic polyamine catabolism. However, administration of a metabolically stable polyamine analogue did not affect disease severity.

Induced hypothermia attenuates the acute lung injury in hemorrhagic shock.

BACKGROUND: In previous animal studies, induction of therapeutic hypothermia (HT) in hemorrhagic shock (HS) had beneficial effects on the hemodynamic and metabolic parameters and on the survival. However, the effect of induced HT on acute lung injury (ALI) in HS has not been investigated. We sought to determine the effects of HT on ALI in HS. METHODS: Male Sprague-Dawley rats (350-390 g; n = 8 per group) were randomized to the normothermia (NT; 36-37 degrees C) group or the moderate HT (27-30 degrees C) group and were subjected to volume-controlled (2 mL/100 g weight) HS (90 minutes) followed by 90 minutes of resuscitation. ALI score, lung malondialdehyde content, and myeloperoxidase activity were measured. The expression of glycogen synthase kinase 3beta (GSK-3beta), phosphorylated GSK-3beta, inducible nitric oxide synthase (iNOS), heat shock protein (HSP) 72, and nuclear factor-kappaB (NF-kappaB) in the lung were compared. RESULTS: ALI score, lung malondialdehyde content, and myeloperoxidase were lower in the HT group. GSK-3beta and iNOS gene expressions in lung tissue were significantly decreased in the HT group (p < 0.05). On the contrary, the expression of phosphorylated GSK-3beta was increased in the HT group (p < 0.001). HSP 72 was expressed in the HT group but not in the NT group. The activated p65 NF-kappaB levels in lung nuclear extract were significantly lower in the NT group (p = 0.03). CONCLUSIONS: HT attenuates HS-induced ALI in rats by the modulation of GSK, HSP 72, iNOS, and NF-kappaB.

Identification of ischemic regions in a rat model of stroke.

BACKGROUND: Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. METHODOLOGY/PRINCIPAL FINDINGS: Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. CONCLUSIONS/SIGNIFICANCE: TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.

[Screening concurrent chemoradiotherapy sensitivity-associated proteins in intermediate stage and advanced cervical carcinoma].

BACKGROUND & OBJECTIVE: Concurrent chemoradiotherapy is a new therapy for intermediate stage and advanced cervical carcinoma, but no valid index for prediction of concurrent chemoradiotherapy sensitivity is available. This study was to screen concurrent chemoradiotherapy sensitivity-associated proteins in intermediate stage and advanced cervical carcinoma. METHODS: Biopsy samples of 10 cervical carcinoma patients were collected before treatment. According to their responses to concurrent chemoradiotherapy (WHO standard), the patients were classified into high sensitivity (HS) group (5 patients) and low sensitivity (LS) group (5 patients). Total protein were extracted from the biopsy samples. Differential proteins were detected by two-dimensional gel electrophoresis (2-DE) and confirmed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Two differentially expressed proteins were further detected by immunohistochemistry in 95 specimens of cervical carcinoma, including 60 high sensitive cases and 35 low sensitive cases. RESULTS: Nineteen differentially expressed proteins were identified: 9 were highly expressed and 10 were lowly expressed in high sensitive group as compared with those in low sensitive group. According to immunohistochemical results, the expression intensity of heat shock protein 70 (HSP70) was higher and that of S100A9 protein was lower in HS group than in LS group; the positive rate of S100A9 was significantly higher and that of HSP70 was significantly lower in HS group than in LS group (88.3% vs. 28.6%, chi2=35.34, P<0.001; 21.7% vs. 85.7%, chi2=36.59, P<0.001). CONCLUSIONS: Differentially expressed proteins that related to concurrent chemoradiotherapy sensitivity of cervical carcinoma are identified. They may be candidate biomarkers for prediction of concurrent chemoradiotherapy sensitivity.

Immunolocalisation of heat shock protein 72 and glycoprotein 96 in colonic adenocarcinoma.

Heat shock protein 72 (HSP72) and glycoprotein 96 (gp96) are highly expressed in cancer tissues. Recent studies indicate the possible roles of HSP72 and gp96 in the development and progression of colonic carcinomas, but detailed information is still ambiguous. In this study, we investigated the correlation between clinical pathology and immunolocalisation of HSP72 and gp96 in human colonic carcinoma. The distribution of HSP72 and gp96 was studied in 160 human colonic carcinomas, with or without metastasis, as well as in mucous membranes adjacent to cancers by means of immunohistochemistry. HSP72 immunoreactivity was detected in 145 of 160 primary tumours (90.6%) and in 44 of 160 mucous membranes adjacent to cancers (27.5%). Gp96 was detected in 81.3% colonic carcinomas and in 13.8% mucous membranes adjacent to cancer. Immunolocalisation of HSP72 and gp96 was mainly cytoplasmic. HSP72 and gp96 immunolabelling was significantly higher in colonic carcinomas with metastasis than in those without metastasis (P<0.05). The results indicate a significant correlation between the immunopositivity of HSP72 and gp96 and the progression of colonic carcinomas. Immunolabelling of HSP72 and gp96 may be useful as diagnostic or prognostic markers in colonic carcinoma.

Sensing danger--Hsp72 and HMGB1 as candidate signals.

Molecules that behave as danger signals are produced when the body is perceived to be under attack, and they alert the immune system to the problem. The immune system can then mount an appropriate response. Two molecules that have received attention as potential danger signals are heat shock protein 72 (Hsp72) and high mobility group box 1 (HMGB1), which are intracellular proteins but are released when cells are under stress, in particular, when necrosis occurs. This review considers the similarities between these two molecules and then contrasts their mechanism of action and problems that can arise when they are overpresented in the extracellular environment. It is proposed that Hsp72 and HMGB1 are members of a suite of danger molecules that provide a fingerprint of the threat, or stressor, to tissue or organism integrity.

Heat shock preconditioning induces protein carbonylation and alters antioxidant protection in superficially injured guinea pig gastric mucosa in vitro.

According to our previous studies, heat shock preconditioning of gastric mucosa requires modulation of protein synthesis and eicosanoid pathways to induce protection against superficial injury. This may be caused by heat shock-induced oxidative stress. We studied the effect of heat shock preconditioning with normothermic recovery on redox status in superficially injured (1.25 mmol NaCl for 5 min) Ussing chamber perfused guinea pig gastric mucosa allowed to recover for 3 hr after injury. Protein oxidation, lipid peroxidation, level of superoxide dismutase, level of heat shock protein 72 (HSP72), and level of oxygen radical absorbance capacity were measured. Superficial injury increased lipid peroxidation. Heat shock preconditioning decreased oxygen radical absorbance capacity and increased protein carbonyl and HSP72 levels, but inhibited electrophysiologic recovery. Exposure to indomethacin and arachidonic acid (AA) partially abolished this pro-oxidative and inhibitory effect on recovery, but maintained HSP72 levels and decreased protein carbonyls, lipid peroxidation, and oxygen radical absorbance capacity. In conclusion, superficial injury increased lipid peroxidation. Heat shock preconditioning alone induced oxidative stress via indomethacin- and AA-sensitive mechanisms. The development of optimal cytoprotective strategy may therefore require control of oxidative stress and modulation of the eicosanoid pathways.

Chaperone-rich cell lysate embedded with BCR-ABL peptide demonstrates enhanced anti-tumor activity against a murine BCR-ABL positive leukemia.

Chaperone proteins are effective antitumor vaccines when purified from a tumor source, some of which are in clinical trials. Such vaccines culminate in tumor-specific T cell responses, implicating the role of adaptive immunity. We have developed a rapid and efficient procedure utilizing an isoelectric focusing technique to obtain vaccines from tumor or normal tissues called chaperone-rich cell lysate (CRCL). Tumor-associated peptides, the currency of T cell-mediated anticancer immunity, are believed to be purveyed by chaperone vaccines. Our purpose was to demonstrate our ability to manipulate the peptide antigen repertoire of CRCL vaccines as a novel anticancer strategy. Our methods allow us to prepare "designer" CRCL, utilizing the immunostimulation activity and the carrying capacity of CRCL to quantitatively acquire and deliver exogenous antigenic peptides (e.g., derived from the oncogenic BCR/ABL protein in chronic myelogenous leukemia). Using fluorescence-based and antigen-presentation assays, we determined that significant quantities of exogenously added peptide could accumulate in "designer" CRCL and could stimulate T cell activation. Further, we concluded that peptide-embedded CRCL, devoid of other antigens, could generate potent immunity against pre-established murine leukemia. Designer CRCL allows for the development of personalized vaccines against cancers expressing known antigens, by embedding antigens into CRCL derived from normal tissue.

Interaction between heat shock protein 72 and alpha-fetoprotein in human hepatocellular carcinomas.

BACKGROUND: AFP in adult serum often signals pathological conditions, particularly the presence of hepatocellular carcinoma (HCC) and germ cell tumors containing yolk sac cell elements. Heat shock protein 72 (HSP72) as a molecular chaperone has been confirmed to overexpress in epithelial carcinoma cells. There may be a possible correlation between the expression of HSP72 and AFP during the growth and differentiation of hepatocellular carcinoma cells. We investigated the interaction between heat shock protein 72 (HSP72) and alpha-fetoprotein (AFP) in human hepatocellular carcinomas. METHODS: The expression and localization of HSP72 and AFP in human hepatocellular carcinomas were determined by immunohistochemistry and confocal laser microscopy. The interaction between HSP72 and AFP in hepatocellular carcinoma cells was analyzed by immunoprecipitation and Western immunoblots. RESULTS: Hepatocellular carcinoma synchronously co-expressed higher level of HSP72 and AFP than in adjacent normal liver tissues. HSP72 were stained in cell nuclei and cytoplasm respectively, while AFP stained in cell plasma. Based on Western blotting methods, AFP was detected in the immunoprecipitate of anti-HSP72 monoclonal antibody (mAb), while HSP72 existed in the immunoprecipitate of anti-AFP mAb. CONCLUSIONS: HSP72 and AFP expression are higher in hepatocellular carcinoma tissues. HSP72 was associated with alpha-fetoprotein in human hepatocellular carcinoma cells. The interaction between HSP72 and AFP in human hepatocellular carcinoma cells can be a new route for studying the pathogenesis and immunotherapy of hepatocellular carcinoma.

Increased expression of heat shock protein 72 protects renal proximal tubular cells from gentamicin-induced injury.

The nephrotoxicity of gentamicin (GM) has been widely recognized. Heat shock protein 72 (HSP72) has been reported to be a cytoprotectant. However, its cytoprotective effect against GM induced kidney injury has not yet been studied. In this study, we investigated the cytoprotective effect of HSP72 on GM-induced nephrotoxicity in vitro. Human Kidney tubular cell line, HK-2 cells were divided into four groups: control group, GM group (cells incubated with GM only), heat shock (HS) group (cells incubated at 43 degrees C for 30 min), and GM plus HS group, respectively. Lactate dehydrogenase (LDH) release increased time-dependently from 24 hr to 96 hr compared to the data of cells treated with GM only. Results of NAG activities, superoxide dismutase (SOD) activities and malondialdehyde (MDA) content were similar to that of the LDH release. The amount of HSP72 positive cells increased significantly at 72 hr after cells were treated with GM only. Both HSP72 protein and gene expression increased significantly at 72 hr when cells were treated with GM. On the other hand, HS induced HSP72 expression markedly. Pretreatment of HS inhibited HK-2 cells from GM-induced injury. It could reduce LDH release and NAG activity. HS also increased SOD activity, and decreased MDA content when cells were damaged by GM. These findings suggested that HS may protect kidney cells from GM-induced injury. Pre-induction of HSP72 may provide therapeutic strategies for nephrotoxicity induced by GM.

Pioglitazone but not glibenclamide improves cardiac expression of heat shock protein 72 and tolerance against ischemia/reperfusion injury in the heredity insulin-resistant rat.

We tested the hypothesis that pioglitazone could restore expression of heat shock protein (HSP)72 in insulin-resistant rat heart. At 12 weeks of age, male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control (LETO) rats were treated with pioglitazone (10 mg x kg(-1) x day(-1)) or glibenclamide (5 mg x kg(-1) x day(-1)) for 4 weeks. Thereafter, hyperthermia (43 degrees C for 20 min) was applied. In response to hyperthermia, the activation of serine/threonine kinase Akt depending on phosphatidylinositol 3 (PI3) kinase was necessary for cardiac expression of HSP72. Hyperthermia-induced activation of Akt and HSP72 expression were depressed in OLETF rat hearts. Pioglitazone but not glibenclamide improved insulin sensitivity in OLETF rats, which was associated with the restoration of Akt activation and HSP72 expression. In experiments with isolated perfused heart, reperfusion-induced cardiac functional recovery was suppressed in OLETF rat hearts, which was improved by pioglitazone but not glibenclamide. Our results suggest that PI3 kinase-dependent Akt activation, an essential signal for HSP72 expression, is depressed in the heart in insulin-resistant OLETF rats, and the results suggest also that the restoration of HSP72 expression and tolerance against ischemia/reperfusion injury by treatment with pioglitazone might be due to an improvement of insulin resistance, leading to restoration of impaired PI3 kinase-dependent Akt activation in response to hyperthermia.

Anabolic steroid- and exercise-induced cardiac stress protein (HSP72) in the rat.

The present study investigated the effects of exercise and anabolic-androgenic steroids on cardiac HSP72 expression. Male Wistar rats were divided into experimental groups: nandrolone exercise (NE, N = 6), control exercise (CE, N = 6), nandrolone sedentary (NS, N = 6), and control sedentary (CS, N = 6). Animals in the NE and NS groups received a weekly intramuscular injection (6.5 mg/kg of body weight) of nandrolone decanoate, while those in the CS and CE groups received mineral oil as vehicle. Animals in the NE and CE groups were submitted to a progressive running program on a treadmill, for 8 weeks. Fragments of the left ventricle were collected at sacrifice and the relative immunoblot contents of HSP72 were determined. Heart weight to body weight ratio was higher in exercised than in sedentary animals (P < 0.05, 4.65 +/- 0.38 vs 4.20 +/- 0.47 mg/g, respectively), independently of nandrolone, and in nandrolone-treated than untreated animals (P < 0.05, 4.68 +/- 0.47 vs 4.18 +/- 0.32 mg/g, respectively), independently of exercise. Cardiac HSP72 accumulation was higher in exercised than in sedentary animals (P < 0.05, 677.16 +/- 129.14 vs 246.24 +/- 46.30 relative unit, respectively), independently of nandrolone, but not different between nandrolone-treated and untreated animals (P > 0.05, 560.88 +/- 127.53 vs 362.52 +/- 95.97 relative unit, respectively) independently of exercise. Exercise-induced HSP72 expression was not affected by nandrolone. These levels of HSP72 expression in response to nandrolone administration suggest either a low intracellular stress or a possible less protection to the myocardium.

Hypothermic circulatory arrest with moderate, deep or profound hypothermic selective antegrade cerebral perfusion: which temperature provides best brain protection?

OBJECTIVE: Selective antegrade cerebral perfusion (SACP) seems to be associated with a better outcome compared to hypothermic circulatory arrest (HCA) alone. This study was undertaken to evaluate the influence of different SACP temperatures on the neurological integrity. METHODS: Twenty-six pigs were included in the study and assigned to 100 min HCA at 20 degrees C body temperature without (n = 6) or with either 10 degrees C (n = 6), 20 degrees C (n = 7) or 30 degrees C (n = 7) of SACP. Haemodynamics, metabolics and neurophysiology (EEG, SSEP, ICP, sagittal sinus saturation) were monitored. Animals were sacrified 4h after reperfusion and brains perfused for histological and molecular genetic assessment. RESULTS: There were no clinically relevant differences in haemodynamics between groups. The rise in ICP during SACP was significantly more marked in the 30 degrees C group (p < 0.05) and remained high during the entire experiment. In the 10 degrees C group the rise in ICP was postponed, but increased during reperfusion. The 20 degrees C group showed a slight increase of ICP over time, but remained significantly lower compared to HCA (p < 0.05). Sagittal sinus saturation decreased during SACP at 30 degrees C (p < 0.05). EEG recovery was most complete in the 20 degrees C group (p < 0.05). RT-PCR analysis of brain tissue revealed a reduction for heat shock protein (HSP-72) in 20 degrees C (p < 0.05) and 10 degrees C animals (p = 0.095). Histopathological evaluation showed a reduction of edema and eosinophilic cells in the groups treated with SACP. CONCLUSION: In this model, SACP is superior to HCA alone. Regarding the optimal temperature for SACP, it seems that 20 degrees C provides adequate brain protection in comparison to the potential detrimental effects of moderate (30 degrees C) and profound (10 degrees C) temperatures.