Exposure system and dosimetry for in vitro studies of biocompatibility of pulse-modulated RF signals of ultrahigh field MRI

A new setup for exposure of human cells in vitro at 37 °C to pulse-modulated 300 and 500 MHz signals of future magnetic resonance imaging (MRI) systems is designed, built up, and characterized. Two dipole antennas, specifically designed for ultrahigh field MRI, are used as radiating structures. The electromagnetic (EM) field distribution inside the incubator containing the cells is computed, and it is shown to be in a good agreement with measurements. The electric field at the cell level is quantified numerically. Local, 1-g average, and averaged over the culture medium volume SAR are provided along with the standard deviation values for each well. Temperature increments are measured inside the culture medium during the exposure using an optical fiber thermometer. Then, we identify the pulse parameters corresponding to the thermal threshold of 1 °C, usually considered as a threshold for thermally induced biological effects. For these parameters, the induction of heat shock proteins is assessed to biologically verify a potential thermal response of cells. The data demonstrate that, under the considered experimental conditions, exposure to pulse-modulated radiations emulating typical ultrahigh field MRI signals, corresponding to temperature increments below 1 °C, does not trigger any heat shock response in human brain cells.

Quantitative analyses of postmortem heat shock protein mRNA profiles in the occipital lobes of human cerebral cortices: implications in cause of death

Quantitative RNA analyses of autopsy materials to diagnose the cause and mechanism of death are challenging tasks in the field of forensic molecular pathology. Alterations in mRNA profiles can be induced by cellular stress responses during supravital reactions as well as by lethal insults at the time of death. Here, we demonstrate that several gene transcripts encoding heat shock proteins (HSPs), a gene family primarily responsible for cellular stress responses, can be differentially expressed in the occipital region of postmortem human cerebral cortices with regard to the cause of death. HSPA2 mRNA levels were higher in subjects who died due to mechanical asphyxiation (ASP), compared with those who died by traumatic injury (TI). By contrast, HSPA7 and A13 gene transcripts were much higher in the TI group than in the ASP and sudden cardiac death (SCD) groups. More importantly, relative abundances between such HSP mRNA species exhibit a stronger correlation to, and thus provide more discriminative information on, the death process than does routine normalization to a housekeeping gene. Therefore, the present study proposes alterations in HSP mRNA composition in the occipital lobe as potential forensic biological markers, which may implicate the cause and process of death.

Endoplasmic reticulum stress is involved in podocyte apoptosis induced by saturated fatty acid palmitate

BACKGROUND

Podocyte apoptosis is recently indicated as an early phenomenon of diabetic nephropathy. Pancreatic β-cells exposed to saturated free fatty acid palmitate undergo irreversible endoplasmic reticulum (ER) stress and consequent apoptosis, contributing to the onset of diabetes. We hypothesized that palmitate could induce podocyte apoptosis via ER stress, which initiates or aggravates proteinuria in diabetic nephropathy.

METHODS

Podocyte apoptosis was detected by 4',6-diamidio-2-phenylindole (DAPI) stained apoptotic cell count and Annexin V-PI stain. The expressions of ER molecule chaperone glucose-regulated protein 78 (GRP78), indicators of ER-associated apoptosis C/EBP homologous protein (CHOP), and Bcl-2 were assayed by Western blotting and real-time PCR. GRP78 and synaptopodin were co-localized by immunofluorescence stain.

RESULTS

Palmitate significantly increased the percentage of cultured apoptotic murine podocytes time-dependently when loading 0.75 mmol/L (10 hours, 13 hours, and 15 hours compared with 0 hour, P < 0.001) and dose-dependently when loading palmitate ranging from 0.25 to 1.00 mmol/L for 15 hours (compared to control, P < 0.001). Palmitate time-dependently and dose-dependently increased the protein expression of GRP78 and CHOP, and decreased that of Bcl-2. Palmitate loading ranging from 0.5 to 1.0 mmol/L for 12 hours significantly increased mRNA of GRP78 and CHOP, and decreased that of Bcl-2 compared to control (P < 0.001), with the maximum concentration being 0.75 mmol/L. Palmitate 0.5 mmol/L loading for 3 hours, 8 hours, and 12 hours significantly increased mRNA of GRP78 and CHOP, and decreased that of Bcl-2 compared to 0 hour (P < 0.001), with the maximum effect at 3 hours. Confocal microscopy demonstrated that GRP78 expression was significantly increased when exposed to 0.5 mmol/L of palmitate for 8 hours compared to control.

CONCLUSION

Palmitate could induce podocyte apoptosis via ER stress, suggesting podocyte apoptosis and consequent proteinuria caused by lipotoxic free fatty acid could be ameliorated by relief of ER stress.

Comprehensive proteome analysis in Cenococcum geophilum Fr. as a tool to discover drought-related proteins

Cenococcum geophilum is a widely distributed ectomycorrhizal fungus potentially playing a significant role in resistance and resilience mechanisms of its tree hosts exposed to drought stress. In this study, we performed a large scale protein analysis in pure cultures of C. geophilum in order to gain first global insights into the proteome assembly of this fungus. Using 1-D gel electrophoresis coupled with ESI-MS/MS, we indentified 638 unique proteins. Most of these proteins were related to the metabolic and cellular processes, and the transport machinery of cells. In a second step, we examined the influence of water deprivation on the proteome of C. geophilum pure cultures at three time points of gradually imposed drought. The results indicated that 12 proteins were differentially abundant in mycelia subjected to drought compared to controls. The induced responses in C. geophilum point towards regulation of osmotic stress, maintainance of cell integrity, and counteracting increased levels of reactive oxygen species formed during water deprivation.

Effects of chronic heat stress on the expressions of heat shock proteins 60, 70, 90, A2, and HSC70 in the rabbit testis

Few studies have focused on the expression of heat shock proteins (HSPs) after chronic heat stress. The objective of this study was to investigate the effect of chronic high temperature-humidity index treatment on the expressions of HSP60, HSP70, HSP90, HSPA2 and HSC70, in the Rex rabbit testis and the expressions of these proteins after recovery from the chronic heat shock. Thirty mature male rabbits of the same age were randomly divided into three groups: control, heat stress, and recovery. The western blot results showed that the expressional levels of HSP60, HSP90, and HSC70 increased significantly and HSPA2 was elevated slightly after a 9-week heat treatment. HSP70 was absent in the control testis and had a high level of expression after heat stress. All of these proteins partially reverted back to normal levels after a 9-week recovery. The immunohistochemical results indicated that the expression patterns of HSP60, HSP90, HSPA2, and HSC70 did not change.

Proteomics of rice in response to heat stress and advances in genetic engineering for heat tolerance in rice

Rice is the most important food crop worldwide. Global warming inevitably affects the grain yields of rice. Recent proteomics studies in rice have provided evidence for better understanding the mechanisms of thermal adaptation. Heat stress response in rice is complicated, involving up- or down-regulation of numerous proteins related to different metabolic pathways. The heat-responsive proteins mainly include protection proteins, proteins involved in protein biosynthesis, protein degradation, energy and carbohydrate metabolism, and redox homeostasis. In addition, increased thermotolerance in transgenic rice was obtained by overexpression of rice genes and genes from other plants. On the other hand, heterologous expression of some rice proteins led to enhanced thermotolerance in bacteria and other easily transformed plants. In this paper, we review the proteomic characterization of rice in response to high temperature and achievements of genetic engineering for heat tolerance in rice.

Identification and validation of rice reference proteins for western blotting

Studies of rice protein expression have increased considerably with the development of rice functional genomics. In order to obtain reliable expression results in western blotting, information on appropriate reference proteins is necessary for data normalization. To date, no published study has identified and systematically validated reference proteins suitable for the investigation of rice protein expression. In this study, nine candidate proteins were selected and their specific antibodies were obtained through immunization of rabbits with either recombinant proteins expressed in Escherichia coli or synthesized peptides. Western blotting was carried out to detect the expression of target proteins in a set of 10 rice samples representing different rice tissues/organs at different developmental stages. The expression stability of the proteins was analysed using geNorm and Microcal Origin 6.0 software. The results indicated that heat shock protein (HSP) and elongation factor 1-α (eEF-1α) were the most constantly expressed among all rice proteins tested throughout all developmental stages, while the proteins encoded by conventional internal reference genes fluctuated in amount. Comparison among the profiling of translation and transcription [expressed sequence tags (EST) and massively parallel signature sequencing (MPSS)] revealed that a correlation existed. Based on the standard curves derived from the antigen-antibody reaction, the concentrations of HSP and eEF-1α proteins in rice leaves were ∼0.12%. Under the present experimental conditions, the lower limits of detection for HSP and eEF-1α proteins in rice were 0.24 ng and 0.06 ng, respectively. In conclusion, the reference proteins selected in this study, and the corresponding antibodies, can be used in qualitative and quantitative analysis of rice proteins.

Capturing cold-stress-related sequence diversity from a wild relative of common bean (Phaseolus angustissimus)

One restriction to the cultivation of common bean, Phaseolus vulgaris L., is its limited tolerance to low temperatures. In the present study, subtraction suppression hybridization was employed to enrich for stress responsive genes in both a chilling-susceptible common bean and a relatively more chilling-tolerant wild bean species, Phaseolus angustissimus. For each species, approximately 11 000 expressed sequence tags were generated. Comparative sequence analysis of the EST collection with the available annotated genome sequences of the model Fabaceae species Medicago truncatula and Glycine max identified protein homologues for approximately 65% and 80% of the Phaseolus sequences, respectively. This difference reflects the closer phylogenetic relationship between the genera Phaseolus and Glycine compared with Medicago. Annotation of the Phaseolus sequences was facilitated through this comparative analysis and indicated that several heat shock proteins, cytochrome P450s, and DNA binding factors were uniquely found among the sequences from the wild species P. angustissimus. The Phaseolus sequences have been made available on a GBrowse implementation using M. truncatula as the reference genome, providing rapid access to the sequence data and associated comparative genome data.

Differential levels of stress proteins (HSPs) in male and female Daphnia magna in response to thermal stress: a consequence of sex-related behavioral differences?

In two independent experiments, we compared: (1) water depth selection (and accompanying temperature selection) by male and female Daphnia magna under different kinds of environmental stress, including the presence of filamentous cyanobacteria, the risk of predation from fish, and the presence of toxic compounds; and (2) sex-dependent production of heat shock proteins (HSP60, 70, and 90) in response to a sudden change in temperature. Male D. magna selected deep water strata, which offer a relatively stable environment, and thereby avoided the threat of predation and the presence of toxic compounds in surface waters. Correlated with this behavior, males reduce their molecular defenses against stress, such as the production of heat shock proteins (HSPs), and do not maintain the physiological machinery that triggers an increase in HSP levels in response to stress. In contrast, female D. magna actively select habitats that offer optimal conditions for growth and production of offspring. Consequently, females are exposed to variable environmental conditions that may be associated with increased stress. To permit survival in these different habitats, D. magna females require molecular mechanisms to protect their cells from rapid changes in stress levels. Thus, they maintain high constitutive levels of the heat shock proteins from HSP 60, 70, and 90 families, and they have the potential to further enhance the production of the majority of these proteins under stress conditions. The results of this study indicate that the separate habitats selected by male and female D. magna result in different patterns of HSP production, leading us to hypothesize that that male and female Daphnia magna adopt different strategies to maximize the fitness of the species.

GRP78/BiP modulation of GRP78/BiP in altering sensitivity to chemotherapy

The glucose-regulated protein 78 (GRP78) is a key regulator of the endoplasmic reticulum (ER) stress response. This chapter discusses how GRP78 may be measured in vitro and in vivo. Because of the authors' expertise and experience with brain tumors, most of our work on GRP78 has focused on malignant gliomas. Here, we present our methodology for determining GRP78 in vitro using glioma cell lines and primary cell cultures, and in measuring GRP78 expression in tissue sections from rodent glioma models and human brain tumors. After discussion of measurement of GRP78 levels, modulation of GRP78 in vitro is demonstrated using glioma cell lines. Lastly, in vivo modulation of GRP78 levels via chemotherapy is determined using intracranial rodent models.

Stress-related proteins compared in diapause and in activated, anoxic encysted embryos of the animal extremophile, Artemia franciscana

Previous work indicated similarities between diapause and anoxic quiescence in encysted embryos (cysts) of the brine shrimp Artemia franciscana. That possibility was examined further in the present study through an immunochemical study of the following stress-related proteins in low speed supernatants and pellets: hsc70, artemin, p26, hsp21, LEA Group 1 protein and p8. Changes in the amounts and locations of these proteins occurred during the initial period after release of diapause cysts from females, and after activated (diapause-terminated) cysts were made anoxic. However, with the passage of incubation time the patterns seen in both kinds of cysts were more similar than different, lending further support to the possibility that activated anoxic embryos retain many of the mechanisms operative in the previous diapause condition.

Influence of yeast macromolecules on sweetness in dry wines: role of the saccharomyces cerevisiae protein Hsp12

Yeast autolysis during lees contact influences the organoleptic properties of wines especially by increasing their sweet taste. Although observed by winemakers, this phenomenon is poorly explained in enology. Moreover, the compounds responsible for sweetness in wine remain unidentified. This work provides new insights in this way by combining sensorial, biochemical and genetic approaches. First, we verified by sensory analysis that yeast autolysis in red wine has a significant effect on sweetness. Moderate additions of ethanol or glycerol did not have the same effect. Second, a sapid fraction was isolated from lees extracts by successive ultrafiltrations and HPLC purifications. Using nano-LC-MS/MS, peptides released by the yeast heat shock protein Hsp12p were distinctly identified in this sample. Third, we confirmed the sweet contribution of this protein by sensorial comparison of red wines incubated with two kinds of yeast strains: a wild-type strain containing the native Hsp12p and a deletion mutant strain that lacks the Hsp12p protein (Δ°HSP12 strain). Red wines incubated with wild-type strain showed a significantly higher sweetness than control wines incubated with Δ°HSP12 strains. These results demonstrated the contribution of protein Hsp12p in the sweet perception consecutive to yeast autolysis in wine.

[Screen and identify of differential proteins expressed in the placenta of Down's syndrome]

OBJECTIVE

To discuss protein marks expressed differentially in placenta of Down's syndrome by means of proteomics.

METHODS

We collected placenta of 18 patients (from March 2009 to December 2009 at Beijing Obstetrics and Gynecology Hospital), and divided them into two groups, one was 10 patients with fetal Down's syndrome, the other was normal pregnancies (normal chromosome) with other diseases. We separated proteins expressed in placentas of two groups by two-dimensional difference gel electrophoresis (2D-DIGE), and then analyzed the differential protein spots by software Decyder 6.5, then, spots differentially expressed by 1.5 fold or more were analyzed by matrix assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS). In the end, the differential expressional levels of partially identified proteins were validated by western blot analysis.

RESULTS

(1) Differential proteins of two groups protein spots of placentas separated by 2D-DIGE were analyzed by software Decyder 6.5 (these colored lights scattered in the image were protein spots), a total of 56 spots out of 352 were differentially expressed (P < 0.05) in two groups. We analyzed 17 protein spots (12 protein spots were over-expressed and 5 protein spots were down-expressed) differentially expressed by 1.5 fold or more by MALDI-TOF-MS. (2) Protein matching after searching protein database, 17 protein spots turn out to be 10 proteins. Four kinds [superoxide dismutase 1 (SOD1), peroxiredoxin 6 (PRDX6), heat shock protein 27 (HSP27), endoplasmic reticulum protein 29 (ERP29)] of them were validated by western blot analysis, the group of fetal Down's syndrome were 0.74 ± 0.12, 0.29 ± 0.10, 0.53 ± 0.16, 0.20 ± 0.09, the group of normal pregnancies were 0.51 ± 0.08, 0.34 ± 0.16, 0.18 ± 0.07, 0.35 ± 0.09, the results confirmed the observed changes in proteomics.

CONCLUSIONS

Compared with normal pregnancies, there were differential proteins expressed in placenta of Down's syndrome. This approach might provide new screening markers in use for prediction of Down's syndrome, however, further study should be done to make these 4 proteins (SOD1, HSP27, ERP29, PRDX6) be new screening markers.

[Expression of GRP78 and GRP94 in the liver tissues and their clinicopathological significance in children with hepatoblastoma]

OBJECTIVE

To study the expression of glucose-regulated protin 78 (GRP78) and glucose-regulated protin 94 (GRP94) in the liver tissues from children with hepatoblastoma (HB) and to investigate the possible clinicopathological values of GRP78 and GRP94 in HB.

METHODS

Liver tissue specimens from 15 children with HB and 10 specimens of normal liver tissues were obtained. EnVison immunohistochemistry was used to detect the expression of GRP78 and GRP94 in the conventional paraffin-embedded liver sections.

RESULTS

The positive rates of GRP78 expression (53% vs 10%; P<0.05) and GRP94 expression (60% vs 10%; P<0.05) in HB liver tissues were significantly higher than those in the normal liver tissues. The positive rates of GRP78 expression in the cases without lymphnode metastasis or in clinical stage I-II were significantly lower than those in the cases with lymphnode metastasis or in clinical stage III-IV (P<0.05). GRP94 showed a decreased tendency of positive expression in the cases without lymphnode metastasis or in clinical stage I-II when compared with the cases with lymphnode metastasis or in clinical stage III-IV, although there were no statistical differences between them.

CONCLUSIONS

GRP78 and GRP94 expression might play important roles in the pathogenesis and progression of pediatric HB.

[Study on rapid detection techniques of PCR-ELISA for Listeria monocytogenes]

OBJECTIVE

To develop rapid PCR-ELISA methods for detecting Listeria monocytogenes, and detect food samples artificially contaminated with Listeria monocytogenes.

METHODS

Specific primers for Listeria monocytogenes pathogenic gene hlyA were selected based on the Genbank data by using molecular biological software DNAman6.0. Digoxigenin-labeled hlyA fragments were obtained by using commercial kit. Specific capture probes were obtained by comparing bacterial pathogenic gene sequences in the Genbank. PCR-ELISA methods were developed and the Listeria monocytogenes isolates with different serotypes were detected. The sensitivity of PCR and PCR-ELISA was determined by artificially inoculating Listeria monocytogenes strains in milk.

RESULTS

It took 6 hours to detect Listeria monocytogenes in food samples by PCR-ELISA. The accordance rate to the bacteriological method was 100%. After 12 h pre-enrichment, the detection limit of PCR-ELISA method was 1 CFU/25 ml milk. The sensitivity of PCR-ELISA method was 10-100 times as PCR.

CONCLUSION

The PCR-ELISA method for rapidly detecting Listeria monocytogenes was established. The sensitivity, specificity and reliability of the method proved to be good. It would be valuable to improve the precaution and prediction abilities of food-borne diseases and enhance the chronergy and accuracy of detection method.

Peripheral leukocyte response to oncological radiotherapy: Expression of heat shock proteins

PURPOSE

To study Heat Shock Proteins (HSP) expression in patients subjected to radiotherapy and their potential use as biomarkers for radiation tolerance. An evaluation is also made of whether irradiated volume is critical to the outcome of normal tissue injury using polymorphonuclear neutrophils as biosensors, and whether HSP antibodies (Ab) may be involved in post-radiotherapy disease.

MATERIAL AND METHODS

Twelve patients receiving the same total dose of radiotherapy, but in three different volumes, and four healthy volunteers used as controls were analysed. hsp27 and 70i mRNA were determined by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Southern-blot, HSP by flow cytometry, and HSP-Ab by Enzyme-linked Immnoadsorbent Assay (ELISA). The clinical protocol included radiation related toxicity based on clinical and analytical scales.

RESULTS

Radiotherapy caused hsp downregulation, maximum in patients with the largest irradiated volumes, and a decrease in intracellular HSP content. Patients with greatest intraleukocyte HSP levels before treatment suffered more severe radiation morbidity. Patients with endocrine neoplasms presented the highest HSP-Ab titers.

CONCLUSIONS

Radiotherapy downregulates hsp27 and 70i, which would enhance radiosensitivity. HSP content prior to treatment is suggested as a prognostic biomarker for radiation tolerance, with circulating leukocytes as biosensors. HSP-Ab may be biomarkers of tumor disease, but do not seem to be involved in the morbidity of acute post-radiotherapy disease, which is closely related to the volumes irradiated.

Proteomic analysis of the nuclear matrix in the early stages of rat liver carcinogenesis: identification of differentially expressed and MAR-binding proteins

Tumor progression is characterized by definite changes in the protein composition of the nuclear matrix (NM). The interactions of chromatin with the NM occur via specific DNA sequences called MARs (matrix attachment regions). In the present study, we applied a proteomic approach along with a Southwestern assay to detect both differentially expressed and MAR-binding NM proteins, in persistent hepatocyte nodules (PHN) in respect with normal hepatocytes (NH). In PHN, the NM undergoes changes both in morphology and in protein composition. We detected over 500 protein spots in each two dimensional map and 44 spots were identified. Twenty-three proteins were differentially expressed; among these, 15 spots were under-expressed and 8 spots were over-expressed in PHN compared to NH. These changes were synchronous with several modifications in both NM morphology and the ability of NM proteins to bind nuclear RNA and/or DNA containing MARs sequences. In PHN, we observed a general decrease in the expression of the basic proteins that bound nuclear RNA and the over-expression of two species of Mw 135 kDa and 81 kDa and pI 6.7-7.0 and 6.2-7.4, respectively, which exclusively bind to MARs. These results suggest that the deregulated expression of these species might be related to large-scale chromatin reorganization observed in the process of carcinogenesis by modulating the interaction between MARs and the scaffold structure.

Identification of 5-fluorouracil response proteins in colorectal carcinoma cell line SW480 by two-dimensional electrophoresis and MALDI-TOF mass spectrometry

Colorectal cancer (CRC) is the second most prevalent cause of cancer-related deaths in the Western world. 5-Fluorouracil (5-FU) is a standard chemotherapeutic drug to treat CRC. However, the response rate is less than 20% and patients who have responded to 5-FU may become resistant. Therefore there is an urgent need to examine the 5-FU response proteins so that patients with no response to 5-FU can change to other treatment strategies promptly. In this study, the proteomic expression profile in a CRC cell line SW480 before and after 5-FU treatment was examined using 2-dimensional electrophoresis technology. Fourteen proteins with differential expression were identified using mass spectrometry and 7 of them were validated using immunocytochemical (ICC) staining. Protein identification indicated that cyclophilin A, cytokeratin 19 (CK19), cytokeratin 8 (CK8), ras-related nuclear protein, heat shock protein 27 (hsp27) and peroxiredoxin 6 (Prx 6) were upregulated whereas heat shock protein 60 (hsp60), cytokeratin 18 (CK18), cytokeratin 9 (CK9), carbamoylphosphate synthetase I, alpha-enolase, heat shock protein 70 (hsp70), nm23 and beta-actin were down-regulated. Seven of the 14 proteins detected were validated by ICC staining, which showed that the expression of hsp27, Prx 6 and hsp70 correlated with that from proteomics profiling. Our results suggest that hsp27, Prx 6 and hsp70 are potential 5-FU response proteins and they may represent potential targets for further evaluation in other 5-FU-sensitive and -resistant CRC cell lines.

Irradiation leads to apoptosis of Kupffer cells by a Hsp27-dependant pathway followed by release of TNF-alpha

In a previous publication, we were able to show that irradiation of Kupffer cells, the liver resident macrophages, leads to an increased TNF-alpha concentration in the culture medium. The pathomechanisms underlying this phenomenon, however, remained to be elucidated. Here, we show that following irradiation of Kupffer cells, the apoptosis rate increased drastically within 48 h. At the same time, the total TNF-alpha concentration in cell lysates of Kupffer cells attached to the culture plate decreased. However, normalization of the TNF-alpha concentration with respect to cell number revealed that TNF-alpha concentration per attached cell remained constant during the observation period. Western blot analysis showed that heat shock protein 27 (Hsp27) is strongly downregulated and bax is upregulated in irradiated Kupffer cells as compared to sham-irradiated cells. Overexpression of Hsp27 in Kupffer cells was shown to prevent the effect of irradiation on bax expression, apoptosis and, at the same time, on increase of TNF-alpha concentration in the Kupffer cell medium. We conclude that irradiation of Kupffer cells leads to apoptosis because of downregulation of Hsp27 and consecutive upregulation of bax expression. Furthermore, we suggest that apoptosis of Kupffer cells leads to an increase of TNF-alpha concentration in the culture medium which may be due to cell death rather than active release or synthesis.

Use of primers based on the heat shock protein genes hsp70, hsp40, and hsp10, for the detection of bovine mastitis pathogens Streptococcus agalactiae, Streptococcus uberis and Streptococcus bovis

Streptococcus agalactiae, Streptococcus uberis, and Streptococcus bovis are three of the major pathogens which cause mastitis in dairy herds. Since conventional methods for the detection of these mastitis pathogens are laborious and time-consuming, rapid methods are needed. With an attempt to know if heat shock protein (HSP) genes other than HSP60 gene, could be used for PCR primer designing, in this study, we tried to design PCR primers based on the heat shock protein genes hsp70, hsp40, and hsp10 for the specific detection of S. agalactiae, S. uberis, and S. bovis, respectively. Using these primers, all the randomly selected target strains could be specifically detected. Bacterial species other than the target organisms, including strains of other Streptococcus spp., and strains of non-Streptococcus spp., would not generate any false positive results. As these PCR primers were used for direct detection of mastitis pathogens, the detection limit was N (N=1-9) x 10(3)CFU/ml of cell dilutions. If a 10h pre-enrichment step was performed, the detection limit was N x 10(0)CFU/ml. Thus, these primers could be used for the specific and sensitive detection of bovine mastitis bacteria.

Application of heat shock protein assay and proteome assay to water from wastewater treatment plant

In this study we applied bioassay using Chinese hamster ovary (CHO) cells with a heat shock protein (HSP) 47 promoter to the effluent of the wastewater treatment plants in Sapporo and we observed the statistically significant HSP production. This implied the effluent contained some organic matter which can stress the CHO cells. To investigate the possible causes of the toxicity of the effluent, we applied the assay to the rejected water from the sludge treatment plant, the mixtures of sewage and rejected water. The evolution of HSP production during the aerobic decay process and thickening process of sludge was also examined. These assay results showed that dissolved microbial products generated and/or released from activated sludge during its decay process in the aeration tank and during thickening and dewatering process in the sludge treatment train contributed to develop HSP production. The proteomics analysis was also applied to the effluent and detected the production of elongation factor 1beta. This result implies that the effluent from wastewater treatment plants may cause changes in cell proteins involved in allergic reaction.

Proteomics finding heat shock protein 27 as a biomarker for resistance of pancreatic cancer cells to gemcitabine

Pancreatic cancer remains a devastating disease and >96% of patients with pancreatic cancer do not survive for more than 5 years. Gemcitabine (2'-deoxy-2'-difluoro-deoxycytidine: Gemzar) appears to be the only clinically effective drug for pancreatic cancer, but it has little impact on outcome. Proteomic analysis of gemcitabine-sensitive cells (KLM1) and resistant pancreatic cells (KLM1-R) was performed to identify target proteins of the gemcitabine. We found seven proteins, HSP27, peroxiredoxin 2, endoplasmic reticulum protein ERp29 precursor, 6-phosphogluconolactonase, triosphospate isomerase, alpha enolase, and nucleophosmine that could play a role in determining the sensitivity of pancreatic cancer to gemcitabine. We knocked down HSP27 in KLM1-R and the sensitivity to gemcitabine was restored. In addition, increased HSP27 expression in tumor specimens was related to higher resistibility to gemcitabine in patients of pancreatic cancer. HSP27 may play an important role in the resistibility to gemcitabine, and it could also be a possible biomarker for predicting the response of pancreatic cancer patients to treatment with gemcitabine.

GRP78 as a novel predictor of responsiveness to chemotherapy in breast cancer

The discovery of predictive factors for chemoresistance is critical for improving adjuvant therapy for cancer patients. The 78-kDa glucose-regulated protein (GRP78), widely used as an indicator of the unfolded protein response (UPR), is induced in the tumor microenvironment. In vitro studies suggest that GRP78 confers chemoresistance to topoisomerase inhibitors, such as Adriamycin (doxorubicin). Here, we report on a retrospective cohort study of 127 stage II and III breast cancer patients who were treated with Adriamycin-based chemotherapy. Archival tumor specimens were available for analysis and the relationship of GRP78 expression level to "time to recurrence" (TTR), used as a surrogate marker for drug resistance, was examined. Our data show that 67% of the study subjects expressed high level of GRP78 in their tumors before the initiation of chemotherapy and suggest an association between GRP78 positivity and shorter TTR [hazard ratio (HR), 1.78; P = 0.16]. Interestingly, subgroup analysis reveals that the HR for the GRP78-positive group increased significantly among patients who did not receive further taxane treatment (HR, 3.00; P = 0.022) and among mastectomy patients (HR, 3.33; P = 0.027). The HR was even stronger among mastectomy patients who did not receive further taxane treatment (HR, 4.82; P = 0.010). The use of GRP78 as a predictor for chemoresponsiveness and the potential interaction of GRP78 and/or the UPR pathways with taxanes warrant larger studies.

Photodynamic therapy resistant human colon carcinoma HT29 cells show cross-resistance to UVA but not UVC light

The isolation of photodynamic therapy (PDT)-resistant HT29 human colon adenocarcinoma cells has been reported previously. These PDT-resistant variants show increased expression of the Hsp27 and BNip3 proteins and a decreased expression of mutant p53 protein compared with parental HT29 cells. Because mutant p53 and increased expression of Hsp27 have been associated with resistance to various chemotherapeutic agents, whereas BNip3 is a potent inducer of apoptosis, we were interested in determining whether these PDT-resistant cells were cross-resistant to other cytotoxic agents. In the present report, we examined the colony survival of the PDT-resistant HT29 variants and several other clonal variants of HT29 cells to ultraviolet light (UV) treatment. The HT29 PDT-resistant variants showed cross-resistance to long-wavelength UVA (320-400 nm) but not to short-wavelength UVC (200-280 nm) light. Cell sensitivity to UVA or UVC was then correlated with Hsp27, BNip3 and mutant p53 protein levels in the PDT-resistant variants as well as in several clonal variants of HT29 cells that express different levels of Hsp27, BNip3 and mutant p53. We show that increased expression of Hsp27 and BNip3 and decreased expression of mutant p53 correlated with increased resistance to UVA. In contrast, increased expression of Hsp27 and BNip3 correlated with increased sensitivity to UVC, whereas increased expression of mutant p53 showed no significant correlation with sensitivity to UVC. These results suggest that the PDT-resistant HT29 cell variants are differentially sensitized to UVA compared with UVC due, in part at least, through the altered expression levels of BNip3, Hsp27 and mutant p53.

Expression of heat shock proteins and stress fiber formation within the arterial vascular tree of adult rats under normal physiological conditions

In this study, we investigated heat shock protein (HSP) expression and stress fiber (SF) formation in endothelial cells (ECs) within the arterial vascular tree of adult rats under normal physiological conditions. Using quantitative immunofluorescence microscopy, we found no significant differences in expression of HSPs 25, 60, 70, and 90 among ECs in the straight portions of rat arteries. In these regions, ECs appeared spindle-shaped and contained short bundles of central SFs. In contrast, ECs in the curved portions or the branch sites of the arteries, exhibited striking differences in HSP expression. ECs with higher HSP expression were localized at the lesser curvature in the curved portions or the distal site of the branch ostia. Moreover, the ECs became polygonal and contained irregular central SFs at the lesser curvature. At the branch sites, downstream ECs became spear-shaped and contained long, thick bundles of central SFs. Curved portions or branch sites are the regions of disturbed flow at which early atherosclerotic lesions are often found. Our results demonstrate these positional differences in HSP expression associated with changes in SF formation within the arterial vascular tree under non-pathological conditions. Our study provides basic information for understanding stress responses via HSP expression and SF formation in vascular ECs and the pathogenesis of atherosclerotic disease.