Anti-HSP70 Antibody [C92F3A-5] (A304773)

Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

Prion diseases are rare and aggressive neurodegenerative disorders caused by the accumulation of misfolded, toxic conformations of the prion protein (PrP). Therapeutic strategies directed at reducing the levels of PrP offer the best chance of delaying or halting disease progression. The challenge, though, is to define pharmacologic targets that result in reduced PrP levels. We previously reported that expression of wild type hamster PrP in flies induces progressive locomotor dysfunction and accumulation of pathogenic PrP conformations, while co-expression of human Hsp70 delayed these changes. To validate the therapeutic potential of Hsp70, we treated flies with drugs known to induce Hsp70 expression, including the Hsp90 inhibitor 17-DMAG and the glucocorticoid dexamethasone. Although the individual treatment with these compounds produced no significant benefits, their combination significantly increased the level of inducible Hsp70, decreased the level of total PrP, reduced the accumulation of pathogenic PrP conformers, and improved locomotor activity. Thus, the combined action of two pharmacological activators of Hsp70 with distinct targets results in sustained high levels of inducible Hsp70 with improved behavioral output. These findings can have important therapeutic applications for the devastating prion diseases and other related proteinopathies.

Exposure of female fetuses to environmental chemicals (ECs) during pregnancy results in a disturbed ovarian adult phenotype. We investigated the influence of pre- and/or post-conception exposure to low-level mixtures of ECs on the structure and function of the fetal ovine ovary. We examined ovarian morphology, expression of oocyte and granulosa cell-specific genes and proteome. Female fetuses were collected at day 110 of gestation, from dams exposed continuously until, and after mating, by grazing in pastures treated with sewage sludge as a fertiliser (TT) or in control fields treated with inorganic fertiliser (CC). In addition, in a cross-over design, fetal ovaries were collected from dams maintained on sludge pastures up to the time of mating but then transferred to control pastures (TC) and, reciprocally, those transferred from control to treated pastures at mating (CT). On examination, the proportion of type 1a follicles (activating primordial follicles) was significantly lower in animals from the CT groups compared with CC and TT groups (P<0.05). Of the 23 ovarian gene transcripts studied, 14 were altered in the ovaries of exposed fetuses (CT, TC, and TT) relative to controls, with the largest number of changes observed in cross-exposure pattern groups (CT or TC). Continuous EC exposure (TT) produced fewer transcript alterations and only two genes (INHBA and GSN) presented differential profiles between CC and TT. Fetal ovarian proteome analysis (2-DE gels) showed, across all exposure groups, 86 differentially expressed protein spots compared to controls. Animals in the CT group exhibited the highest number (53) while TC and TT presented the same number of affected protein spots (42). Fetal ovarian proteins with altered expression included MVP (major vault protein) and several members of the heat-shock family (HSPA4L, HSP90AA1 and HSF1). The present findings indicate that continuous maternal EC exposure before and during gestation, are less deleterious for fetal ovarian development than a change in maternal EC exposure between pre and post-conception. The pathways by which the ovary responds to this chemical stress were common in TT, CT, TC exposed foetuses. In addition to the period of pregnancy, the pre-conception period appears also as crucial for conditioning long-term effects of EC exposure on ovarian development and primordial follicle reserve and hence future fertility.

Prolidase is the only human enzyme responsible for the digestion of iminodipeptides containing proline or hydroxyproline at their C-terminal end, being a key player in extracellular matrix remodeling. Prolidase deficiency (PD) is an intractable loss of function disease, characterized by mutations in the prolidase gene. The exact causes of activity impairment in mutant prolidase are still unknown. We generated three recombinant prolidase forms, hRecProl-231delY, hRecProl-E412K and hRecProl-G448R, reproducing three mutations identified in homozygous PD patients. The enzymes showed very low catalytic efficiency, thermal instability and changes in protein conformation. No variation of Mn(II) cofactor affinity was detected for hRecProl-E412K; a compromised ability to bind the cofactor was found in hRecProl-231delY and Mn(II) was totally absent in hRecProl-G448R. Furthermore, local structure perturbations for all three mutants were predicted by in silico analysis. Our biochemical investigation of the three causative alleles identified in perturbed folding/instability, and in consequent partial prolidase degradation, the main reasons for enzyme inactivity. Based on the above considerations we were able to rescue part of the prolidase activity in patients' fibroblasts through the induction of Heath Shock Proteins expression, hinting at new promising avenues for PD treatment.

Huntington Disease (HD) is caused by an abnormal expansion of polyQ tract in the protein named huntingtin (Htt). HD pathology is featured by accumulation and aggregation of mutant Htt in striatal and cortical neurons. Aberrant Htt degradation is implicated in HD pathogenesis. The aim of this study was to investigate the regulatory role of chaperone-mediated autophagy (CMA) components, heat shock protein cognate 70 (Hsc70) and lysosome-associated protein 2A (LAMP-2A) in degradation of Htt fragment 1-552aa (Htt-552). A cell model of HD was produced by overexpression of Htt-552 with adenovirus. The involvement of CMA components in degradation of Htt-552 was determined with over-expression or silencing of Hsc70 and LAMP-2A. The results confirmed previous reports that both macroautophagy and CMA were involved in degradation of Htt-552. Changing the levels of CMA-related proteins affected the accumulation of Htt-552. The lysosomal binding and luminal transport of Htt-552 was demonstrated by incubation of Htt-552 with isolated lysosomes. Expansion of the polyQ tract in Htt-552 impaired its uptake and degradation by lysosomes. Mutation of putative KFERQ motif in wild-type Htt-552 interfered with interactions between Htt-552 and Hsc70. Endogenous Hsc70 and LAMP-2A interacted with exogenously expressed Htt-552. Modulating the levels of CMA related proteins degraded endogenous full-length Htt. These studies suggest that Hsc70 and LAMP-2A through CMA play a role in the clearance of Htt and suggest a novel strategy to target the degradation of mutant Htt.

Current cancer therapies including cytotoxic chemotherapy, radiation and hyperthermic therapy induce acute proteotoxic stress in tumour cells. A major challenge to cancer therapeutic efficacy is the recurrence of therapy-resistant tumours and how to overcome their emergence. The current study examines the concept that tumour cell exposure to acute proteotoxic stress results in the acquisition of a more advanced and aggressive cancer cell phenotype. Specifically, we determined whether heat stress resulted in an epithelial-to-mesenchymal transition (EMT) and/or the enhancement of cell migration, components of an advanced and therapeutically resistant cancer phenotype. We identified that heat stress enhanced cell migration in both the lung A549, and breast MDA-MB-468 human adenocarcinoma cell lines, with A549 cells also undergoing a partial EMT. Moreover, in an in vivo model of thermally ablated liver metastases of the mouse colorectal MoCR cell line, immunohistological analysis of classical EMT markers demonstrated a shift to a more mesenchymal phenotype in the surviving tumour fraction, further demonstrating that thermal stress can induce epithelial plasticity. To identify a mechanism by which thermal stress modulates epithelial plasticity, we examined whether the major transcriptional regulator of the heat shock response, heat shock factor 1 (HSF1), was a required component. Knockdown of HSF1 in the A549 model did not prevent the associated morphological changes or enhanced migratory profile of heat stressed cells. Therefore, this study provides evidence that heat stress significantly impacts upon cancer cell epithelial plasticity and the migratory phenotype independent of HSF1. These findings further our understanding of novel biological downstream effects of heat stress and their potential independence from the classical heat shock pathway.

We have previously shown that heat shock protein 70 (HSP70) markedly inhibits H(2)O(2)-induced apoptosis in mouse C2C12 myogenic cells by reducing the release of Smac. However, the molecular mechanism by which HSP70 interferes with Smac release during oxidative stress-induced apoptosis is not understood. In the current study, we showed that HSP70 increased the stability of Bcl-2 during oxidative stress. An antisense phosphorothioate oligonucleotide against Bcl-2 caused selective inhibition of Bcl-2 protein expression induced by HSP70 and significantly attenuated HSP70-mediated cell protection against H(2)O(2)-induced release of Smac and apoptosis. Taken together, our results indicate that there are important relationships among HSP70, Bcl-2, release of Smac, and induction of apoptosis by oxidative stress.

We have shown previously that activation of STAT1 contributes to the pathogenesis of Wilms tumor. This neoplasm caricatures metanephric development and is believed to originate from embryonic renal mesenchymal progenitors that lose their ability to undergo mesenchymal-epithelial transition (MET). Therefore, we hypothesized that STAT1 is also activated and functional during metanephric development. Here we have demonstrated that both STAT1 and STAT3 are activated during normal development of the embryonic kidney. Furthermore, activation of STAT1 stimulated the proliferation of metanephric mesenchymal cells, but it prevented MET and tubulogenesis induced by leukemia inhibitory factor, which preferentially activates STAT3. Consistent with its negative regulation of metanephric mesenchymal differentiation, inhibition of STAT1 activation with protein kinase CK2 inhibitor TBB or RNAi-mediated knockdown of STAT1 promoted differentiation of metanephric progenitors and abolished the effect of cytokine-induced STAT1 activation in these cells. Additionally, a cell-permeable peptide that inhibits STAT1-mediated transactivation by targeting the STAT1 N-domain also blocked cytokine-induced STAT1-dependent proliferation in metanephric progenitors and promoted LIF-induced MET and tubulogenesis. Finally, the STAT1 peptide inhibitor caused the down regulation of survival/anti-apoptotic factors, Mcl-1 and Hsp-27, and induced apoptosis in renal tumor cells with constitutively active STAT1, indicating that STAT1 is required for these cells to survive. These findings show that both metanephric progenitors and renal tumor cells utilize a STAT1-dependent mechanism for growth or survival.

Background: High mobility group protein box 1 (HMGB1) is a DNA binding protein located in nucleus. It is released into extracellular fluid where it acts as a novel proinflammatory cytokine which interacts with Toll like receptor 4 (TLR4) to activate nuclear factor-?B (NF-?B). This sequence of events is involved in tumor growth and progression. However, the effects of HMGB1, TLR4 and NF-?B on epidermal tumors remain unclear.

Methods: Human epidermal tumor specimens were obtained from 96 patients. Immunohistochemistry was used to detect expression of HMGB1, TLR4 and NF-?B p65 in human epidermal tumor and normal skin specimens. Western blot analysis was used to detect the expression of NF-?B p65 in epithelial cell nuclei in human epidermal tumor and normal tissues.

Results: Immunohistochemistry and western blot analysis indicated a progressive but statistically significant increase in p65 expression in epithelial nuclei in benign seborrheic keratosis (SK), precancerous lesions (PCL), low malignancy basal cell carcinoma (BCC) and high malignancy squamous cell carcinoma (SCC) (P <0.01). The level of extracellular HMGB1 in SK was significantly higher than in normal skin (NS) (P <0.01), and was higher than in SCC but without statistical significance. The level of TLR4 on epithelial membranes of SCC cells was significantly higher than in SK, PCL, BCC and NS (P <0.01). There was a significant positive correlation between p65 expression in the epithelial nuclei and TLR4 expression on the epithelial cell membranes (r = 0.3212, P <0.01).

Conclusions: These findings indicate that inflammation is intensified in parallel with increasing malignancy. They also indicate that the TLR4 signaling pathway, rather than HMGB1, may be the principal mediator of inflammation in high-grade malignant epidermal tumors. Combined detection of p65 in the epithelial nuclei and TLR4 on the epithelial membranes may assist the accurate diagnosis of malignant epidermal tumors.

Docetaxel is a taxane-derived chemotherapy drug that has been approved for treatment of prostate cancer. While docetaxel is frequently used as a treatment for hormone-refractory prostate cancer, a subset of patients either do not respond to this treatment or those that do respond eventually become resistant to the drug over time. Resistance to docetaxel is complex and multi-factoral and further understanding of the cellular biochemistry underlying resistance is vital to improve treatment efficacy. To identify proteins altered in the resistant phenotype, three parental cell lines DU145, 22RV1 and PC-3, as well as their docetaxel resistant sub-lines, were subjected to quantitative label-free LC-MS proteomic profiling. A total of 189 significant (p < 0.05) protein abundance changes were identified in the DU145 resistant sub-lines, 254 in the 22RV1 sub-lines, and 51 and 72 in the 8 and 12 nM resistant PC-3 sub-lines, respectively. From these, 29 proteins demonstrated a significant (p < 0.05) fold change across two or more resistant variants. These included proteins indicative of an epithelial-to-mesenchemyl transition as well as altered heat shock response elements.

Currently, no reports exist concerning the expression patterns and developmental changes of heat shock proteins (HSPs) in the reproductive system of the male rabbit. In the present study, the testes of rabbits were collected at post-natal months 1, 2, 3, 4, 5, and 40. HSP60, HSC70, HSP90, and HSPA2 were detected by both Western blot and immunohistochemical methods. The expression levels of HSP60 and HSC70 showed no apparent change during the developmental progress. HSP90 increased at the second month; prior to the third month, HSPA2 was expressed at a low level. Immunohistochemistry localized HSP60 in the cytoplasm of all of the cell types in the testis and in the apical pole of the spermatids. The distribution pattern of HSC70 and HSP90 was similar, both being mainly located in the spermatids of stage VII-VIII and in the cytoplasm of the spermatogonium. HSPA2 staining was mainly observed in the cytoplasm of pachytene spermatocytes and spermatids in testes of 3-, 4-, 5-, and 40-month-old rabbits. These results provide a basic reference point for studying the functions of HSPs in the male rabbit reproductive system and should be beneficial for the future determination of the mechanisms of heat shock on male rabbit fertility.

In the present study, the effects of dietary resveratrol on the induction of heat shock proteins, transcription factors and antioxidative enzyme system in liver of quails under heat stress were investigated. A total of 180 (55-day-old) female Japanese quails (Coturnix coturnix japonica) were reared either at 22 °C for 24 h/day (thermoneutral, TN) or 34 °C for 8 h/day (heat stress, HS; 09:00-17:00 hours) for 12 weeks. Birds in both environments were randomly fed one of three diets: basal diet and basal diet added with either 200 or 400 mg of resveratrol per kg of diet. The results showed that exposure to high ambient temperature induced decreases in feed intake, egg production, and hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities but increases in hepatic malondialdehyde (MDA) concentrations (p < 0.001). Liver Hsp70, Hsp90 and NF-?B expression was greater while Nrf2 expression was lower for quails reared under the heat stress than for those reared under the TN environment (p < 0.0001). There were linear increases in feed intake, egg production, hepatic SOD, CAT, and GSH-Px activities as well as Nrf2 expression, but linear decreases in hepatic MDA concentrations and Hsp70, Hsp90, and NF-?B expressions with increasing supplemental resveratrol level (p < 0.0001). Two-way treatment interactions revealed that the degree of restorations in all response variables was more notable under the high ambient temperature than that of the TN environment as dietary resveratrol concentration was increased. The results of the present study suggest that supplemental resveratrol reduces oxidative stress in heat-stressed quails through modulating the hepatic heat shock proteins and nuclear transcription factors.

Fatty livers are particularly susceptible to mitochondrial alterations after cold preservation. We thus aimed to improve graft integrity by brief hypothermic oxygenation prior to warm reperfusion. Macrovesicular steatosis was induced in rat livers by fasting and subsequent feeding of a fat-free diet enriched with carbohydrates. Fatty livers were retrieved and stored ischemically at 4 degrees C for 20 hours in histidine-tryptophan-ketoglutarate solution. Hypothermic reconditioning (HR) was performed in some livers by insufflation of gaseous oxygen via the caval vein during the last 90 minutes of preservation. Viability was assessed upon isolated reperfusion. HR resulted in a significant (approximately 5-fold) reduction of parenchymal (alanine aminotransferase and lactate dehydrogenase) and mitochondrial (glutamate dehydrogenase) enzyme release. Functional recovery (bile production, oxygen consumption, and tissue levels of adenosine triphosphate) was significantly improved by HR. In untreated grafts, cellular autophagy (cleavage of LC3B and protein expression of beclin-1) was significantly impaired (<50% of baseline) after preservation/reperfusion but was restored to normal values by HR. HR also increased cleavage of caspase 9 (P < 0.5) and caspase 3 enzyme activity (by a factor of 1.5). In contrast, histological signs of tissue necrosis were abundant after reperfusion in untreated livers and largely abrogated in reconditioned livers. In conclusion, HR limits mitochondrial defects and restores basal rates of cellular autophagy. This may represent a rescue mechanism for maintaining cellular homeostasis and tissue survival.

Background: To investigate if microRNAs (miRNAs) play a role in regulating h-ERG trafficking in the setting of chronic oxidative stress as a common deleterious factor for many cardiac disorders.

Methods: We treated neonatal rat ventricular myocytes and HEK293 cells with stable expression of h-ERG with H2O2 for 12 h and 48 h. Expression of miR-17-5p seed miRNAs was quantified by real-time RT-PCR. Protein levels of chaperones and h-ERG trafficking were measured by Western blot analysis. Luciferase reporter gene assay was used to study miRNA and target interactions. Whole-cell patch-clamp techniques were employed to record h-ERG K(+) current.

Results: H-ERG trafficking was impaired by H2O2 after 48 h treatment, accompanied by reciprocal changes of expression between miR-17-5p seed miRNAs and several chaperones (Hsp70, Hsc70, CANX, and Golga2), with the former upregulated and the latter downregulated. We established these chaperones as targets for miR-17-5p. Application miR-17-5p inhibitor rescued H2O2-induced impairment of h-ERG trafficking. Upregulation of endogenous by H2O2 or forced miR-17-5p expression either reduced h-ERG current. Sequestration of AP1 by its decoy molecule eliminated the upregulation of miR-17-5p, and ameliorated impairment of h-ERG trafficking.

Conclusions: Collectively, deregulation of the miR-17-5p seed family miRNAs can cause severe impairment of h-ERG trafficking through targeting multiple ER stress-related chaperones, and activation of AP1 likely accounts for the deleterious upregulation of these miRNAs, in the setting of prolonged duration of oxidative stress. These findings revealed the role of miRNAs in h-ERG trafficking, which may contribute to the cardiac electrical disturbances associated with oxidative stress.

Background: Cardiopulmonary bypass (CPB) may cause acute lung injury leading to increased morbidity and mortality after cardiac surgery. Preconditioning by inhaled carbon monoxide reduces pulmonary inflammation during CPB. We hypothesized that inhaled carbon monoxide mediates its anti-inflammatory and cytoprotective effects during CPB via induction of pulmonary heat shock proteins (Hsps).

Methods: Pigs were randomized either to a control group, to standard CPB, to carbon monoxide+CPB, or to quercetin (a flavonoid and unspecific inhibitor of the heat shock response)+control, to quercetin+CPB, and to quercetin+carbon monoxide+CPB. In the carbon monoxide groups, lungs were ventilated with 250 ppm carbon monoxide in addition to standard ventilation before CPB. At various time points, lung biopsies were obtained and pulmonary Hsp and cytokine concentrations determined.

Results: Haemodynamic parameters were largely unaffected by CPB, carbon monoxide inhalation, or administration of quercetin. Compared with standard CPB, carbon monoxide inhalation significantly increased the pulmonary expression of the Hsps 70 [27 (SD 3) vs 69 (10) ng ml(-1) at 120 min post-CPB, P<0.05] and 90 [0.3 (0.03) vs 0.52 (0.05) after 120 min CPB, P<0.05], induced the DNA binding of heat shock factor-1, reduced interleukin-6 protein expression [936 (75) vs 320 (138) at 120 min post-CPB, P<0.001], and decreased CPB-associated lung injury (assessed by lung biopsy). These carbon monoxide-mediated effects were inhibited by quercetin.

Conclusions: As quercetin, a Hsp inhibitor, reversed carbon monoxide-mediated pulmonary effects, we conclude that the anti-inflammatory and protective effects of preconditioning by inhaled carbon monoxide during CPB in pigs are mediated by an activation of the heat shock response.