Assessment of multiple types of DNA damage in human placentas from smoking and nonsmoking women in the Czech Republic

Three classes of DNA damage were assessed in human placentas collected (2000–2004) from 51 women living in the Teplice region of the Czech Republic, a mining area considered to have some of the worst environmental pollution in Europe in the 1980s. Polycyclic aromatic hydrocarbon (PAH)‐DNA adducts were localized and semiquantified using immunohistochemistry (IHC) and the Automated Cellular Imaging System (ACIS). More generalized DNA damage was measured both by ³²P‐postlabeling and by abasic (AB) site analysis. Placenta stained with antiserum elicited against DNA modified with 7β,8α‐dihydroxy‐9α,10α‐epoxy‐7,8,9,10‐tetrahydro‐benzo[a]pyrene (BPDE) revealed PAH‐DNA adduct localization in nuclei of the cytotrophoblast (CT) cells and syncytiotrophoblast (ST) knots lining the chorionic villi. The highest levels of DNA damage, 49‐312 PAH‐DNA adducts/10⁸ nucleotides, were found by IHC/ACIS in 14 immediately fixed placenta samples. An additional 37 placenta samples were stored frozen before fixation and embedding, and because PAH‐DNA adducts were largely undetectable in these samples, freezing was implicated in the loss of IHC signal. The same placentas (n = 37) contained 1.7–8.6 stable/bulky DNA adducts/10⁸ nucleotides and 0.6–47.2 AB sites/10⁵ nucleotides. For all methods, there was no correlation among types of DNA damage and no difference in extent of DNA damage between smokers and nonsmokers. Therefore, the data show that DNA from placentas obtained in Teplice contained multiple types of DNA damage, which likely arose from various environmental exposures. In addition, PAH‐DNA adducts were present at high concentrations in the CT cells and ST knots of the chorionic villi. Environ. Mol. Mutagen. 52:58–68, 2011. © 2010 Wiley‐Liss, Inc.     

Chaperones in the parotid gland: localization of heat shock proteins in human adult salivary glands

Heat shock proteins (HSPs) are expressed or increased in response to various biological stresses. Moreover, these 'stress proteins' seem to be expressed by some cells living in physiological conditions. From then on, they could play an important physiological role in normal cell functioning. The best-known physiological role of these HSP proteins is to act as 'molecular chaperones'. In this context, we have investigated the immunohistochemical expression of HSP27, HSP70, HSP90 and HSP110 in 10 human adult salivary glands. To highlight the presence of RNAm encoding HSP70, an in situ hybridization was performed. In our material, HSP27 was strongly expressed in the cytoplasm of striated duct cells and in some myoepithelial cells. The same localization was less stained for HSP70 and HSP90. The immunocytochemical reaction was weak or negative for HSP110 in striated ducts. HSPs were not expressed in acinic cells. In situ hybridization gave a positive signal in striated ducts with a probe encoding HSP70. Epithelial cells of the striated ducts and myoepithelial cells expressed HSP27, HSP70 and HSP90. These HSPs probably act in part as molecular chaperones for protein synthesis, transport and for several interactions between HSPs and different proteins.     

Expression of heat shock proteins in salivary gland tumors. Immunohistochemical study of HSP27, HSP70, HSP90, and HSP110: apropos of 50 cases

Heat shock proteins (HSPs) are known to be increased in response to biological stress. Recently some authors described their presence in tumors. Our immunohistochemical investigations revealed the expression of HSP27, HSP70, HSP90 and HSP110 in most of benign tumors of salivary glands (33 cases). In the malignant tumors, the reaction was immunopositive for HSP70 and HSP90 in 13/17 cases; but HSP27 and HSP110 were only expressed in 5/17 cases. In conclusion HSPs were expressed less in malignant than in benign cells. These results suggest that the loss of some HSPs may be a possible sign of malignancy.     

Expressions of HSP70 and HSP27 in hepatocellular carcinoma

The heat shock proteins (HSPs) are ubiquitous molecules induced in cells exposed to various stress conditions, including carcinogenesis. The HSP70 and HSP27 among HSPs are of special relevance in human cancer inhibiting apoptosis. The aim of this study is to investigate the expressions of HSP70 and HSP27 in hepatocellular carcinoma (HCC) in association to tumor cell proliferation and apoptosis. We examined the expressions of HSP70 and HSP27 by immunohistochemical staining in 71 cases of HCC, and then related their expressions to clinicopathologic parameters and expressions of p53, Ki-67 and Apotag. HSP70 and HSP27 were frequently stained in the cytoplasm and nuclei of tumor cells, but not in the non-neoplastic hepatocytes. Immunoreactivities of HSP70 and HSP27 were observed in 56.3% and 61.9% of HCCs, respectively. HSP70 immunoreactivity correlated with high Ki-67 labeling indices (LIs) (p=0.0159), large tumor size (p=0.0129), presence of portal vein invasion (p=0.0231), and high tumor stage (p=0.0392). HSP27 immunoreactivity significantly related with the subgroup of HBV-associated HCCs (p=0.0003), but not with the others. Both HSP70 and HSP27 immunoreactivities showed no relation to Apotag LIs or p53 immunoreactivity. In conclusion, expressions of HSP70 and HSP27 may play an important role in hepatocarcinogenesis, and especially HSP70 showed a close relationship to the pathological parameters associated with tumor progression and high Ki-67 LIs. Our results could be additional evidence that HSP70 expressions can contribute to not only hepatocarcinogenesis but also tumor progression by promoting tumor cell proliferation.     

Can we assess an acute myocardial infarction in patients with acute coronary syndrome according to diagnostic accuracy of heat shock proteins?

Heat shock proteins (HSPs) have changed very little with evolution, suggesting that they play important role(s) in cellular survival. Specifically, HSPs protect cells from induced cell death. Their expression is triggered by heat or other stress, such as ischemia. HSPs provide protection against protein denaturation, although they slightly differ with respect to group affiliation. Release of HSPs from necrotic and ischemic cardiomyocytes into the intercellular space and plasma may correlate with the intensity of the pro-inflammatory response observed during and immediately after myocardial infarction. We hypothesized that the plasma concentration of particularly inducible forms of HSPs from different groups (HSP 90, HSP 70, HSP 60 and/or HSP 20) can be used as early specific markers for diagnosing myocardial infarction in patients with acute coronary syndrome. Our hypothesis is supported by the following data: (I) HSP expression occurs very early after acute coronary events; (II) HSP concentrations increase rapidly in the peripheral blood; (III) HSP concentrations correlate with markers of myocardial necrosis and pro-inflammatory biochemical parameters. The magnitude of the increase in plasma HSP concentrations over initial concentrations during the period of highest sensitivity and specificity of the assay could be important for early detection of myocardial infarction and distinguishing it from unstable angina. We suggest that these parameters, along with close observation of patients with chest pain, will assist providers who must differentiate between acute myocardial damage and other organ diseases.     

A single bout of eccentric exercise increases HSP27 and HSC/HSP70 in human skeletal muscle

Changes in heat shock proteins (HSPs), HSP27 and HSC/HSP70 were characterized in human biceps brachii muscle following damaging high-force eccentric exercise. Male and female volunteers performed a maximal eccentric resistance exercise with the elbow flexor muscles of the non-dominant arm known to be sufficient to cause substantial muscle damage. Protein extracts of biopsy tissue samples taken 48 h post-exercise were immunoblotted for HSC/HSP70 and HSP27. Densitometric analysis demonstrated that these proteins increased significantly (P < 0.01) in the damaged biceps brachii relative to the control arm. The HSC/HSP70 increased 1064% in the exercised sample while HSP27 increased by 234%. Although the literature reports a muscular heat shock response following aerobic, oxidative exercise, this is the first documentation of increases in protein expression of both HSC/HSP70 and HSP27 in human skeletal muscle in response to a single bout of resistance exercise.     

The repeated bout effect and heat shock proteins: intramuscular HSP27 and HSP70 expression following two bouts of eccentric exercise in humans

Exercise-induced damage significantly and predictably alters indirect indicators of muscle damage after one bout of damaging exercise but this response is dampened following a second bout of the same exercise performed 1-6 weeks later. Previously we have described a marked increase in the levels of heat shock proteins (HSPs) HSP27 and HSP70 in human biceps muscle following one bout of high-force eccentric exercise. The purpose of the present study was to examine the intramuscular HSP27 and HSP70 response following two identical bouts of exercise [bout 1 (B1) and bout 2 (B2), separated by 4 weeks] relative to indirect indices of muscle damage. Ten human subjects performed 50 high-force eccentric contractions with their non-dominant forearm flexors; muscle damage of the biceps brachii was evaluated 48 h post-exercise with indirect indices [serum creatine kinase (CK) activity, soreness, isometric maximal voluntary contraction (MVC) force and relaxed arm angle] and immunoblotting of high ionic strength muscle biopsy extracts for both HSPs. Not unexpectedly, the indirect indicators of damage changed dramatically and significantly (P < 0.01) after B1 but had a much smaller response after B2. The magnitude of the HSP response was the same after both bouts of exercise, though the control and exercised samples of B2 demonstrated a lower basal HSP expression. Thus, though both indirect and cellular indicators of exercise-induced muscle damage demonstrate an adaptation consequent to the first bout of exercise, these adaptations are quite different. It is possible that the lower basal HSP expression of the cellular response mediates the attenuation of damage associated with B2 as indicated by indirect indices.     

Damage to developing mouse skeletal muscle myotubes in culture: protective effect of heat shock proteins

Damage to skeletal muscle occurs following excessive exercise, upon reperfusion following ischaemia and in disease states, such as muscular dystrophy. Key mechanisms by which damage is thought to occur include a loss of intracellular calcium homeostasis, loss of energy supply to the cell, increased activity of oxidising free radical-mediated reactions and activation of apoptosis pathways. An increased cellular content of heat shock proteins (HSPs) has been shown to protect skeletal muscle against some forms of damage, although the mechanistic basis of this protection is not clearly understood. The aim of this study was to establish a cell culture-based model of damage to C₂C₁₂ skeletal muscle cells using the calcium ionophore, A23187 and the mitochondrial uncoupler, 2,4-dinitrophenol (DNP) as damaging agents. Treatment of cells with 1 m m DNP for 60 min resulted in the release of 63.5 % of intracellular creatine kinase (CK) activity over the 3 h experimental period. Treatment of cells with 10 μ m A23187 for 30 min resulted in the release of 47.9 % of CK activity. Exposure of myotubes to a period of hyperthermia resulted in a significant increase in their content of HSP25, HSP60, HSC70 (heat shock cognate) and HSP70. This increase in HSPs was associated with significant protection against both DNP-induced and A23187-induced damage to the myotubes. These results indicate that an increased content of HSPs may provide protection against the muscle damage that occurs by a pathological increase in intracellular calcium or uncoupling of the mitochondrial respiratory chain.     

Expression of heat shock proteins 70 and 47 in tissues following short-pulse laser irradiation: Assessment of thermal damage and healing

In order to develop effective laser-based therapeutics, the extent of laser-induced damage must be quantified for given laser parameters. Therefore, we want to determine the spatiotemporal expression patterns of heat shock proteins, both to understand the roles of heat shock proteins in laser-induced tissue damage and repair and to develop heat shock proteins as tools to illustrate the extent of laser-induced damage and wound healing following irradiation. We exposed anesthetized mice to the focused beam of a short-pulse Nd:YAG laser (1064 nm; 200 ns pulsewidth) for 15 s, while measuring temperature distribution in the skin using an infrared thermal camera. Following irradiation, we examined expression of HSP47 and HSP70 over time (0–24 h) as indicators of the heat shock response and recovery from damage in the laser-irradiated region. Expression patterns of HSP70 and HSP47 as detected by immunohistochemistry and confocal microscopy delineate the extent of damage and the process of healing in tissue. Both HSP70 and HSP47 were expressed in dermis and epidermis following laser irradiation, and the spatial and temporal changes in HSP expression patterns define the laser-induced thermal damage zone and the process of healing in tissues. HSP70 may define biochemically the thermal damage zone in which cells are targeted for destruction, and HSP47 may illustrate the process of recovery from thermally induced damage. Studying the effects of different laser parameters on the expression of HSPs will allow development of effective laser therapies that provide accurate and precise tissue ablation and may promote rapid wound healing following laser-based surgery.     

Expression of heat shock proteins in osteosarcoma and its relationship to prognosis

The prognosis of osteosarcoma has been improved by chemotherapy. Heat shock proteins (HSPs) assist in folding proteins at posttranslation and degeneration under stress. We investigated the effect of HSPs on survival in osteosarcoma. Conventional osteosarcomas of the extremities from 70 patients aged 30 years or younger were used. Preoperational chemotherapy was performed in all cases. Tissues at surgery and biopsy were immunohistochemically stained with anti-HSP27, HSP47, HSP60, HSP70, HSP90alpha, HSP90beta, and p53 antibodies. We classified the cases in which more than 10% of tumor cells were positive into the overexpressing group. Overall survival was compared between the groups either overexpressing HSPs or not using Wilcoxon's test and Cox's proportional hazard model. The overexpression rate at biopsy was 22% (HSP27), 88% (HSP47), 66% (HSP60), 48% (HSP70(, 47% (HSP90alpha), 31% (HSP90beta), and 17% (p53), respectively. The rate at surgery was 33% (HSP27), 94% (HSP47), 60% (HSP60), 49% (HSP70), 28% (HSP90alpha), 40% (HSP90beta), and 17% (p53), respectively. HSP27 and p53 overexpression at biopsy had a negative prognostic value. HSP27 showed the strongest negative prognostic value in osteosarcoma. It is therefore important to investigate further its function in cellular regulation and drug resistance.     

The induction of heat shock protein-72 attenuates cisplatin-induced acute renal failure in rats

Induction of heat shock proteins (HSPs) is thought to play a protective role in ischaemic acute renal failure (ARF). However the role of HSPs in nephrotoxic ARF is not well explored. The aim of this study was to clarify the effects of the induction of HSP70s on cisplatin (CDDP) (6 mg/kg i.v.)-induced ARF in rats. Uranyl acetate (UA) or sodium arsenite (SA) were administered i.v. 14 days or 1 day respectively before CDDP injection to induce HSPs. Serum creatinine (SCr), tubular damage score and the numbers of apoptotic (TUNEL-positive) cells were examined 5 days after CDDP injection. The expression of HSP72, B-cell lymphoma gene product-2 (Bcl-2) and Bax were evaluated by Western blot analysis. We also investigated the effect of co-administration of chelerythrine chloride (Chel), which inhibits the induction of HSPs, with SA on the expression of HSP72 and nephrotoxicity. Pretreatment with UA or SA significantly induced renal HSP72 expression. Both UA and SA attenuated the CDDP-induced increase in SCr and tubular damage scores. Co-administration of Chel with SA abolished the SA-induced increment of HSP72 and the beneficial effects of SA. The protective effects of the induction of HSP72 were associated with an increased renal Bcl-2/Bax ratio and the reduction of TUNEL-positive cells in the outer stripe of outer medulla. Our findings suggest that HSP72 attenuates CDDP-induced nephrotoxicity. The protective effects of HSP72 are associated with an increased Bcl-2/Bax ratio and less apoptosis.     

热休克蛋白在结肠炎和胰腺炎时的表达特点及大麻类物质WIN和O-1602的影响

目的: 观察几种热休克蛋白(heat-shock proteins, HSPs)在实验性结肠炎和实验性急性胰腺炎炎症组织中表达的变化,同时研究大麻经典受体1和受体2激动剂WIN55和212-2(WIN),以及新型受体GPR55激动剂O-1602对HSPs表达的影响及可能的意义。方法: 用C57/BL小鼠,通过连续饮用7 d 4%葡聚糖硫酸钠(dextran sulfate sodium, DSS)复制结肠炎模型;通过腹腔注射雨蛙肽(cerulein,50 μg/kg,每小时1次,连续 6次)复制急性胰腺炎模型。同时设各模型组及WIN、O-1602治疗组,检测不同处理组小鼠结肠和胰腺组织形态学改变、血浆促炎细胞因子包括白细胞介素-6(IL-6)及细胞因子诱导的中性粒细胞化学趋化因子-1(cytokine-induced neutrophil chemoattractant-1,CINC-1) 的水平和淀粉酶活性,同时用免疫组化方法检测结肠和胰腺组织HSPs(HSP27、HSP60、和HSP70)的表达特点。结果: 在DSS诱导的小鼠结肠炎及 cerulein 诱导的小鼠胰腺炎模型,其结肠和胰腺组织分别出现典型的炎症及损伤,血浆促炎因子水平升高(P<0.05),在胰腺炎小鼠还有血浆胰淀粉酶活性的升高。在结肠炎症组织,HSP27表达明显升高,HSP60和HSP70表达降低;WIN具有一定的抗炎作用,并能显著提高结肠炎结肠组织HSP27和HSP70的表达(P<0.05)。在急性胰腺炎的胰腺组织,HSP27和HSP70表达升高,HSP60表达有所降低; O-1602有一定的抗炎作用,也能提高HSP70的表达,但总体来看,对这3种HSPs的影响均不太明显(P>0.05)。结论: DSS和cerulein分别诱导小鼠结肠炎和急性胰腺炎的发生;在这2种模型的炎症组织中HSPs的表达变化不一。大麻类物质WIN和O-1602均有一定的抗炎作用,也在一定程度上提高部分HSPs的表达。HSPs的高表达是否与大麻类物质的抗炎作用有关值得进一步的研究。     

热休克蛋白在子宫内膜异位症中的表达及意义

目的 探讨热休克蛋白27（HSP27）和HSP70在子宫内膜异位症发病中的作用。方法 采用免疫组化链霉菌抗生素蛋白－过氧化物酶染色法（SP法），检测子宫内膜异位症中56例异位内膜与在位内膜（30例）中HSP27和HSP70的表达。采用原位杂交，检测HSP70mRNA的水平，并与正常子宫内膜相比较。结果 免疫组化结果显示，异位内膜组织中HSP27与HSP70均呈高表达，与正常内膜组的表达差异显著（P＜0．01），而且失去其在正常内膜组织中表达的周期性变化。卵巢子宫内膜异位症组（OEM）与子宫腺肌症组（AM）组中，HSP27和HSP70的表达无显著差异（P＞0．05）。原位杂交结果显示，HSP70 mRNA（分别为P＜0．01和P＜0．05）。HSP27与HSP70的表达水平，同OEM的严重性无关。结论 异位内膜组织中的HSP70基因被激活，转录增加。HSP27和HSP70呈高表达，可能在EM的发病中起重要作用。     

Gene expression levels of heat shock proteins in the soleus and plantaris muscles of rats after hindlimb suspension or spaceflight

Gene expression levels of heat shock proteins (HSPs) in the slow-twitch soleus and fast-twitch plantaris muscles of rats were determined after hindlimb suspension or spaceflight. Male rats were hindlimb-suspended for 14 d or exposed to microgravity for 9 d. The mRNA expression levels of HSP27, HSP70, and HSP84 in the hindlimb-suspended and microgravity-exposed groups were compared with those in the controls. The mRNA expression levels of the 3 HSPs in the soleus muscle under normal conditions were higher compared with those in the plantaris muscle. The mRNA expression levels of the 3 HSPs in the soleus muscle were inhibited by hindlimb suspension and spaceflight. The mRNA expression levels of the 3 HSPs in the plantaris muscle did not change after hindlimb suspension. It is suggested that the mRNA expression levels of the 3 HSPs are regulated by the mechanical and neural activity levels, and therefore the decreased mRNA expression levels of HSPs in the slow-twitch muscle following hindlimb suspension and spaceflight are related to a reduction in the mechanical and neural activity levels.     

Expression of heat shock protein 70 and endothelial nitric oxide synthase in placental tissue of preeclamptic and intrauterine growth-restricted pregnancies

Ischemia, hypoxia, and elevated vascular resistance disturb placental functions by increasing oxidative stress. Heat shock protein 70 (HSP70) is an oxidative stress marker. Endothelial nitric oxide synthase (eNOS) is a nitric oxide enzyme with a key role in pathologic and physiologic angiogenesis and vasculogenesis. This study was performed to investigate the role of oxidative stress in the pathogenesis of preeclampsia and intrauterine growth-restricted (IUGR) pregnancies by comparing the levels of HSP70 and eNOS in placentas from women with these diseases and those with healthy pregnancies.     

The heat shock protein response following eccentric exercise in human skeletal muscle is unaffected by local NSAID infusion

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely consumed in relation to pain and injuries in skeletal muscle, but may adversely affect muscle adaptation probably via inhibition of prostaglandin synthesis. Induction of heat shock proteins (HSP) represents an important adaptive response in muscle subjected to stress, and in several cell types including cardiac myocytes prostaglandins are important in induction of the HSP response. This study aimed to determine the influence of NSAIDs on the HSP response to eccentric exercise in human skeletal muscle. Healthy males performed 200 maximal eccentric contractions with each leg with intramuscular infusion of the NSAID indomethacin or placebo. Biopsies were obtained from m. vastus lateralis before and after (5, 28 hrs and 8 days) the exercise bout from both legs (NSAID vs unblocked leg) and analysed for expression of the HSPs HSP70, HSP27 and αB-crystallin (mRNA and protein). NSAID did not affect the mRNA expression of any of the HSPs. Compared to pre values, the mRNA expression of all HSPs was increased; αB-crystallin, 3.6- and 5.4-fold; HSP70, 26- and 3.4-fold; and HSP27: 4.8- and 6.5-fold at 5 and 28 hrs post-exercise, respectively (all p < 0.008). Immunohistochemical stainings for αB-crystallin and HSP70 revealed increased staining in some samples but with no differences between legs. Changes in force-generating capacity correlated with both αB-crystallin and HSP70 mRNA and immunohistochemisty data. Increased expression of HSPs was observed on mRNA and protein level following eccentric exercise; however, this response was unaffected by local intramuscular infusion of NSAIDs     

急性心肌梗死猝死者心肌细胞hsf1和HSP70改变的意义

目的探讨急性心肌梗死猝死者梗死区心肌细胞内热休克转录因子1（hsfl）和热休克蛋白70（HSP70）改变的临床意义。方法分别用RT-PCR和免疫组化法检测（IHC）18例急性心肌梗死猝死者（研究组）和15例心脏正常因车祸快速死亡者（对照组）心肌细胞中hsfl和HSP70基因的mRNA和蛋白表达量。结果急性心肌梗死猝死者心肌细胞hsfl和HSP70的mRNA表达量都显著高于正常对照组（P〈0.01），且hsfl和HSP70mRNA的表达量之间呈显著的正相关关系（P〈0．001）。急性心肌梗死猝死者心肌细胞hsfl和HSP70蛋白在细胞浆和细胞核表达较对照组显著增强（P〈0.001），其中hsfl蛋白主要在心肌细胞核内表达，HSP70蛋白主要在心肌细胞浆内表达。结论急性心肌梗死猝死者心肌细胞内hsfl和HSPT0可能共同参与了急性心肌梗死的病理生理过程．这一过程可能是热休克反应的另一调节途径。     

The involvement of heat shock proteins in murine liver regeneration

Partial hepatectomy （PHx） in mammals is a very common experimental model to investigate the process of liver regeneration. The surgery itself could give birth to a series of stresses, such as the temporary raise of body temperature and the ischaemia-reperfusion injury. Heat shock proteins （HSPs） were a family of stress-inducible proteins involved in maintaining cell homeostasis and regulating the immune system. In our study, we intended to investigate the expression and role of HSPs in liver regeneration. Using RT-PCR and Western blotting, we determined the expression in regenerating liver of HSP27, HSP60, HSP70 and HSP90 in mRNA level and protein level, respectively, with mice treated with sham operation as controls. We also used quercertin as an inhibitior of HSPs to explore their effects on liver regeneration. We found that hepatic expression of HSPs increased at the early phase of liver regeneration and declined to the constitutively low level later. Moreover, quercetin pretreatment delayed the progress of liver regeneration in mice via inhibition of HSPs. The results indicated that HSPs played an important role in liver regeneration. Cellular ＆ Molecular Immunology. 2007;4（1）：53-57.     

Heat shock proteins (HSPs) 27, 72 and 73 in normal and pre-ulcerative mucosa of the gastric pars oesophagea in swine

Heat shock proteins (HSPs), known to play a key role in cellular homeostasis, may also play a role in the defensive mechanisms of gastric mucosa. By means of appropriate immunohistochemical and immunobiochemical techniques, the expression of HSP27, HSP72 and HSP73 within the epithelium of normal and pre-ulcerative (hyperkeratinized) mucosa of the pars oesophagea of abattoir pigs was assessed. In normal mucosa, HSP72 and HSP73 expression was mainly limited to the basal epithelial cell layer, whereas HSP27 expression was consistently detected within the superficial epithelial cell layers. In hyperkeratinized mucosa, HSP72 and HSP73 immunoreactivity appeared to be more widespread, becoming very intense within epithelial cells affected by hydropic degeneration. Hyperkeratinized mucosa also showed HSP27 immunoreactivity, which was particularly intense in epithelial areas affected by hydropic degeneration. Western blot analysis confirmed HSP27, HSP72 and HSP73 expression in normal and in pre-ulcerative mucosa of the pars oesophagea. Semi-quantitative analysis showed that for all three HSPs the immunoreactivity was more intense in pre-ulcerative mucosa than in normal mucosa. The different expression patterns observed may have functional significance; further studies are needed, however, to define the role of HSPs in swine oesophagogastric lesions, the aetiology and pathogenesis of which are largely unknown.     

Intracellular and extracellular functions of heat shock proteins: repercussions in cancer therapy

Stress or heat shock proteins (HSPs) are the most conserved proteins present in both prokaryotes and eukaryotes. Their expression is induced in response to a wide variety of physiological and environmental insults. These proteins play an essential role as molecular chaperones by assisting the correct folding of nascent and stress-accumulated misfolded proteins, and preventing their aggregation. HSPs have a dual function depending on their intracellular or extracellular location. Intracellular HSPs have a protective function. They allow the cells to survive lethal conditions. Various mechanisms have been proposed to account for the cytoprotective functions of HSPs. Several HSPs have also been demonstrated to directly interact with various components of the tightly regulated programmed cell death machinery, upstream and downstream of the mitochondrial events. On the other hand, extracellular located or membrane-bound HSPs mediate immunological functions. They can elicit an immune response modulated either by the adaptive or innate immune system. This review will focus on HSP27, HSP70, and HSP90. We will discuss the dual role of these HSPs, protective vs. immunogenic properties, making a special emphasis in their utility as targets in cancer therapy.