Heat shock proteins and cell proliferation

Fitness correlates of blubber oxidative stress and cellular defences in grey seals (Halichoerus grypus): support for the life-history-oxidative stress theory from an animal model of simultaneous lactation and fasting

Life-history-oxidative stress theory predicts that elevated energy costs during reproduction reduce allocation to defences and increase cellular stress, with fitness consequences, particularly when resources are limited. As capital breeders, grey seals are a natural system in which to test this theory. We investigated oxidative damage (malondialdehyde (MDA) concentration) and cellular defences (relative mRNA abundance of heat shock proteins (Hsps) and redox enzymes (REs)) in blubber of wild female grey seals during the lactation fast (n = 17) and summer foraging (n = 13). Transcript abundance of Hsc70 increased, and Nox4, a pro-oxidant enzyme, decreased throughout lactation. Foraging females had higher mRNA abundance of some Hsps and lower RE transcript abundance and MDA concentrations, suggesting they experienced lower oxidative stress than lactating mothers, which diverted resources into pup rearing at the expense of blubber tissue damage. Lactation duration and maternal mass loss rate were both positively related to pup weaning mass. Pups whose mothers had higher blubber glutathione-S-transferase (GST) expression at early lactation gained mass more slowly. Higher glutathione peroxidase (GPx) and lower catalase (CAT) were associated with longer lactation but reduced maternal transfer efficiency and lower pup weaning mass. Cellular stress, and the ability to mount effective cellular defences, could proscribe lactation strategy in grey seal mothers and thus affect pup survival probability. These data support the life-history-oxidative stress hypothesis in a capital breeding mammal and suggest lactation is a period of heightened vulnerability to environmental factors that exacerbate cellular stress. Fitness consequences of stress may thus be accentuated during periods of rapid environmental change.

Androgenesis-Based Doubled Haploidy: Past, Present, and Future Perspectives

Androgenesis, which entails cell fate redirection within the microgametophyte, is employed widely for genetic gain in plant breeding programs. Moreover, androgenesis-responsive species provide tractable systems for studying cell cycle regulation, meiotic recombination, and apozygotic embryogenesis within plant cells. Past research on androgenesis has focused on protocol development with emphasis on temperature pretreatments of donor plants or floral buds, and tissue culture optimization because androgenesis has different nutritional requirements than somatic embryogenesis. Protocol development for new species and genotypes within responsive species continues to the present day, but slowly. There is more focus presently on understanding how protocols work in order to extend them to additional genotypes and species. Transcriptomic and epigenetic analyses of induced microspores have revealed some of the cellular and molecular responses required for or associated with androgenesis. For example, microRNAs appear to regulate early microspore responses to external stimuli; trichostatin-A, a histone deacetylase inhibitor, acts as an epigenetic additive; ά-phytosulfokine, a five amino acid sulfated peptide, promotes androgenesis in some species. Additionally, present work on gene transfer and genome editing in microspores suggest that future endeavors will likely incorporate greater precision with the genetic composition of microspores used in doubled haploid breeding, thus likely to realize a greater impact on crop improvement. In this review, we evaluate basic breeding applications of androgenesis, explore the utility of genomics and gene editing technologies for protocol development, and provide considerations to overcome genotype specificity and morphogenic recalcitrance in non-model plant systems.

Effect of in-vitro heat stress challenge on the function of blood mononuclear cells from dairy cattle ranked as high, average and low immune responders

Background

The warming climate is causing livestock to experience heat stress at an increasing frequency. Holstein cows are particularly susceptible to heat stress because of their high metabolic rate. Heat stress negatively affects immune function, particularly with respect to the cell-mediated immune response, which leads to increased susceptibility to disease. Cattle identified as having enhanced immune response have lower incidence of disease. Therefore, the objective of this study was to evaluate the impact of in vitro heat challenge on blood mononuclear cells from dairy cattle, that had previously been ranked for immune response, in terms of heat shock protein 70 concentration, nitric oxide production, and cell proliferation.

Results

Blood mononuclear cells from dairy cattle classified as high immune responders, based on their estimated breeding values for antibody and cell-mediated responses, produced a significantly greater concentration of heat shock protein 70 under most heat stress treatments compared to average and low responders, and greater cell-proliferation across all treatments. Similarly, a trend was observed where high responders displayed greater nitric oxide production compared to average and low responders across heat treatments.

Conclusion

Overall, these results suggest that blood mononuclear cells from high immune responder dairy cows are more thermotolerant compared to average and low immune responders.

HIF1α-dependent induction of the mitochondrial chaperone TRAP1 regulates bioenergetic adaptations to hypoxia

The mitochondrial paralog of the Hsp90 chaperone family TRAP1 is often induced in tumors, but the mechanisms controlling its expression, as well as its physiological functions remain poorly understood. Here, we find that TRAP1 is highly expressed in the early stages of Zebrafish development, and its ablation delays embryogenesis while increasing mitochondrial respiration of fish larvae. TRAP1 expression is enhanced by hypoxic conditions both in developing embryos and in cancer models of Zebrafish and mammals. The TRAP1 promoter contains evolutionary conserved hypoxic responsive elements, and HIF1α stabilization increases TRAP1 levels. TRAP1 inhibition by selective compounds or by genetic knock-out maintains a high level of respiration in Zebrafish embryos after exposure to hypoxia. Our data identify TRAP1 as a primary regulator of mitochondrial bioenergetics in highly proliferating cells following reduction in oxygen tension and HIF1α stabilization.

Heat Shock Proteins and Their Role in Pregnancy: Redefining the Function of "Old Rum in a New Bottle"

Pregnancy in humans is a multi-step complex physiological process comprising three discrete events, decidualization, implantation and placentation. Its overall success depends on the incremental advantage that each of the preceding stages passes on to the next. The success of these synchronized sequels of events is an outcome of timely coordination between them. The pregnancy events are coordinated and governed primarily by the ovarian steroid hormones, estrogen and progesterone, which are essentially ligand-activated transcription factors. It's well known that intercellular signaling of steroid hormones engages a plethora of adapter proteins that participate in executing the biological functions. This involves binding of the hormone receptor complex to the DNA response elements in a sequence specific manner. Working with Drosophila melanogaster, the heat shock proteins (HSPs) were originally described by Ferruccio Ritossa back in the early 1960s. Over the years, there has been considerable advancement of our understanding of these conserved families of proteins, particularly in pregnancy. Accumulating evidence suggests that endometrial and uterine cells have an abundance of HSP27, HSP60, HSP70 and HSP90, implying their possible involvement during the pregnancy process. HSPs have been found to be associated with decidualization, implantation and placentation, with their dysregulation associated with implantation failure, pregnancy loss and other feto-maternal complications. Furthermore, HSP is also associated with stress response, specifically in modulating the ER stress, a critical determinant for reproductive success. Recent advances suggest a therapeutic role of HSPs proteins in improving the pregnancy outcome. In this review, we summarized our latest understanding of the role of different members of the HSP families during pregnancy and associated complications based on experimental and clinical evidences, thereby redefining and exploring their novel function with new perspective, beyond their prototype role as molecular chaperones.

ACTH(6-9)PGP Peptide Protects SH-SY5Y Cells from H2O2, tert-Butyl Hydroperoxide, and Cyanide Cytotoxicity via Stimulation of Proliferation and Induction of Prosurvival-Related Genes

Stabilized melanocortin analog peptide ACTH(6-9)PGP (HFRWPGP) possesses a wide range of neuroprotective activities. However, its mechanism of action remains poorly understood. In this paper, we present a study of the proproliferative and cytoprotective activity of the adrenocorticotropic hormone fragment 6-9 (HFRW) linked with the peptide prolyine-glycyl-proline on the SH-SY5Y cells in the model of oxidative stress-related toxicity. The peptide dose-dependently protected cells from H2O2, tert-butyl hydroperoxide, and KCN and demonstrated proproliferative activity. The mechanism of its action was the modulation of proliferation-related NF-κB genes and stimulation of prosurvival NRF2-gene-related pathway, as well as a decrease in apoptosis.

Loss of DIAPH3, a Formin Family Protein, Leads to Cytokinetic Failure Only under High Temperature Conditions in Mouse FM3A Cells

Cell division is essential for the maintenance of life and involves chromosome segregation and subsequent cytokinesis. The processes are tightly regulated at both the spatial and temporal level by various genes, and failures in this regulation are associated with oncogenesis. Here, we investigated the gene responsible for defects in cell division by using murine temperature-sensitive (ts) mutant strains, tsFT101 and tsFT50 cells. The ts mutants normally grow in a low temperature environment (32 °C) but fail to divide in a high temperature environment (39 °C). Exome sequencing and over-expression analyses identified Diaph3, a member of the formin family, as the cause of the temperature sensitivity observed in tsFT101 and tsFT50 cells. Interestingly, Diaph3 knockout cells showed abnormality in cytokinesis at 39 °C, and the phenotype was rescued by re-expression of Diaph3 WT, but not Diaph1 and Diaph2, other members of the formin family. Furthermore, Diaph3 knockout cells cultured at 39 °C showed a significant increase in the level of acetylated α-tubulin, an index of stabilized microtubules, and the level was reduced by Diaph3 expression. These results suggest that Diaph3 is required for cytokinesis only under high temperature conditions. Therefore, our study provides a new insight into the mechanisms by which regulatory factors of cell division function in a temperature-dependent manner.

Heat-Shock Proteins Gene Expression in Peripheral Blood Mononuclear Cells as an Indicator of Heat Stress in Beef Calves

Simple Summary

This study explores the effects of heat stress on the expression of various heat-shock protein (HSP) genes in bovine peripheral blood mononuclear cells (PBMCs) and cell viability as an indicator of stress in beef calves. We found that heat stress inhibits cell proliferation and increases the expression of HSPs in an in vitro model. In addition, HSPs were found to regulate the physiological mechanisms of adaptation to heat stress in an in vivo model. The results showed that HSPs expression in PBMCs can be used as an indicator of heat stress (HS) in beef calves.

Abstract

This study was conducted to investigate the effect of HS on HSPs gene expression in bovine PBMCs of beef calves in in vitro and in vivo models. In the in vitro experiment, blood samples were collected from the jugular vein of five beef calves (age: 174.2 ± 5.20 days, BW: 145.2 ± 5.21 kg). In the in vivo experiment, sixteen Korean native male beef calves (age: 169.6 ± 4.60 days, BW: 136.9 ± 6.23 kg) were exposed to ambient temperature for seven days (22 to 24 °C, relative humidity 60%; temperature–humidity index (THI) = 68 to 70) and subsequently to the temperature and humidity corresponding to the target THI level for 21 days (HS). For PBMC isolation, blood samples were collected every three days. In the in vitro model, the cell viability was significantly decreased in HS groups compared with the control group (p = 0.015). The expression of HSP70 (p = 0.022), HSP90 (p = 0.003) and HSPB1 (p = 0.026) genes was increased in the HS group in in vitro model. In the in vivo experiment, the HSP70 gene expression was increased after sudden exposure to HS conditions (severe THI levels; THI = 88 to 90), whereas HSP90 and HSPB1 showed no differences among the THI groups (p > 0.05). However, in the severe THI group, the HSP70 gene expression returned to normal range after six days of continuous HS. In conclusion, the HSP70 gene plays a pivotal role in protecting cells from damage and is sensitive to HS in immune cells compared with other HSP genes in in vitro and in vivo models. In addition, the in vivo models suggest that calves exhibit active physiological mechanisms of adaptation to HS after six days of continuous exposure by regulating the HSP70 gene expression.

"Click" reaction mediated synthesis of costunolide and dehydrocostuslactone derivatives and evaluation of their cytotoxic activity

As part of pharmacological-phytochemical integrated studies on medicinal plants from Indian flora, costunolide (1) and dehydrocostus lactone (2), were isolated as major phytochemicals from Saussurea lappa, a plant traditionally used in different Asian systems of medicine. A series of 1,4-disubstituted-1,2,3-triazoles conjugates were synthesized through diastereo selective Michael addition followed by regioselective Huisgen 1,3-dipolar cycloaddition reactions. All these triazolyl derivatives (5a-5j) & (7a-7j) were well characterized using modern spectroscopic techniques and evaluated for their anticancer activity against a panel of five human cancerous celllines. The results indicated that all the analogs displayed moderate cytotoxic activity.

Introducing differential expression of human heat shock protein 27 in hepatocellular carcinoma: moving toward identification of cancer biomarker

Previously, it has to be acknowledged that overexpressed heat shock protein B27 (HSPB27) have been implicated in the etiology of wide range of human cancers. However, the molecular mechanism leading to the disease initiation to progression in liver cancer is still unknown. Present work was undertaken to investigate the differentially expressed HSPB27 in association with those damages that lead to liver cancer development. For the identification of liver cancer biomarker, samples were subjected to comparative proteomic analysis using two-dimensional gel electrophoresis (2-DE) and were further validated by Western blot and immunohistochemical analysis. After validation, in silico studies were applied to demonstrate the significantly induced phosphorylated and S-nitrosylated signals. The later included the interacting partner of HSPB27, i.e., mitogen-activated protein kinase-3 and 5 (MAPK3 and 5), ubiquitin C (UBC), v-akt murine thymoma viral oncogene homolog 1 (AKT1), mitogen-activated protein kinase 14 (MAPK14), and tumor protein p53 (TP53), which bestowed with critical capabilities, namely, apoptosis, cell cycling, stress activation, tumor suppression, cell survival, angiogenesis, proliferation, and stress resistance. Taking together, these results shed new light on the potential biomarker HSPB27 that overexpression of HSPB27 did lead to upregulation of their interacting partner that together demonstrate their possible role as a novel tumor progressive agent for the treatment of metastasis in liver cancer. HSPB27 is a promising diagnostic marker for liver cancer although further large-scale studies are required. Also, molecular profiling may help pave the road to the discovery of new therapies.

The involvement of J-protein AtDjC17 in root development in Arabidopsis

In a screen for root hair morphogenesis mutants in Arabidopsis thaliana L. we identified a T-DNA insertion within a type III J-protein AtDjC17 caused altered root hair development and reduced hair length. Root hairs were observed to develop from trichoblast and atrichoblast cell files in both Atdjc17 and 35S::AtDJC17. Localization of gene expression in the root using transgenic plants expressing proAtDjC17::GUS revealed constitutive expression in stele cells. No AtDJC17 expression was observed in epidermal, endodermal, or cortical layers. To explore the contrast between gene expression in the stele and epidermal phenotype, hand cut transverse sections of Atdjc17 roots were examined showing that the endodermal and cortical cell layers displayed increased anticlinal cell divisions. Aberrant cortical cell division in Atdjc17 is proposed as causal in ectopic root hair formation via the positional cue requirement that exists between cortical and epidermal cell in hair cell fate determination. Results indicate a requirement for AtDJC17 in position-dependent cell fate determination and illustrate an intriguing requirement for molecular co-chaperone activity during root development.

Influence of heating and cyclic tension on the induction of heat shock proteins and bone-related proteins by MC3T3-E1 cells

Stress conditioning (e.g., thermal, shear, and tensile stress) of bone cells has been shown to enhance healing. However, prior studies have not investigated whether combined stress could synergistically promote bone regeneration. This study explored the impact of combined thermal and tensile stress on the induction of heat shock proteins (HSPs) and bone-related proteins by a murine preosteoblast cell line (MC3T3-E1). Cells were exposed to thermal stress using a water bath (44°C for 4 or 8 minutes) with postheating incubation (37°C for 4 hours) followed by exposure to cyclic strain (equibiaxial 3%, 0.2 Hz, cycle of 10-second tensile stress followed by 10-second rest). Combined thermal stress and tensile stress induced mRNA expression of HSP27 (1.41 relative fold induction (RFI) compared to sham-treated control), HSP70 (5.55 RFI), and osteopontin (1.44 RFI) but suppressed matrix metalloproteinase-9 (0.6 RFI) compared to the control. Combined thermal and tensile stress increased vascular endothelial growth factor (VEGF) secretion into the culture supernatant (1.54-fold increase compared to the control). Therefore, combined thermal and mechanical stress preconditioning can enhance HSP induction and influence protein expression important for bone tissue healing.

Involvement of heat shock proteins in gluten-sensitive enteropathy

Gluten-sensitive enteropathy, also known as coeliac disease (CD), is an autoimmune disorder occurring in genetically susceptible individuals that damages the small intestine and interferes with the absorption of other nutrients. As it is triggered by dietary gluten and related prolamins present in wheat, rye and barley, the accepted treatment for CD is a strict gluten-free diet. However, a complete exclusion of gluten-containing cereals from the diet is often difficult, and new therapeutic strategies are urgently needed. A class of proteins that have already emerged as drug targets for other autoimmune diseases are the heat shock proteins (HSPs), which are highly conserved stress-induced chaperones that protect cells against harmful extracellular factors. HSPs are expressed in several tissues, including the gastrointestinal tract, and their levels are significantly increased under stress circumstances. HSPs exert immunomodulatory effects, and also play a crucial role in the maintenance of epithelial cell structure and function, as they are responsible for adequate protein folding, influence the degradation of proteins and cell repair processes after damage, and modulate cell signalling, cell proliferation and apoptosis. The present review discusses the involvement of HSPs in the pathophysiology of CD. Furthermore, HSPs may represent a useful therapeutic target for the treatment of CD due to the cytoprotective, immunomodulatory, and anti-apoptotic effects in the intestinal mucosal barrier.

Methodological considerations for heat shock of the nematode Caenorhabditis elegans

Stress response pathways share commonalities across many species, including humans, making heat shock experiments valuable tools for many biologists. The study of stress response in Caenorhabditis elegans has provided great insight into many complex pathways and diseases. Nevertheless, the heat shock/heat stress field does not have consensus as to the timing, temperature, or duration of the exposure and protocols differ extensively between laboratories. The lack of cohesiveness makes it difficult to compare results between groups or to know where to start when preparing your own protocol. We present a discussion of some of the major hurdles to reproducibility in heat shock experiments as well as detailed protocols for heat shock and hormesis experiments.

Heat shock protein 90 is associated with hyperplasia and neoplastic transformation of canine prostatic epithelial cells

Heat shock protein 90 (HSP90) is a molecular chaperone that regulates critical signalling proteins of cancer development and progression. Abnormal levels of HSP90 have been observed in human prostatic carcinoma (PC), with prognostic and therapeutic implications. Since spontaneously arising canine PC is a valuable model for the human disease, the aim of this study was to evaluate the immunohistochemical expression of HSP90 in two normal canine prostates, 17 canine prostates with benign prostatic hyperplasia (BPH) and five canine prostates with PC. HSP90 was expressed in the cytoplasm of epithelial cells in all samples, with a significant increase in labelled cells in PCs. Nuclear labelling was observed occasionally in normal tissue, but was increased in BPH and PC. HSP90 immunoreactivity in preneoplastic lesions (proliferative inflammatory atrophy and prostatic intraepithelial neoplasia) was similar to that in PCs. Increased HSP90 expression in canine PCs suggests the involvement of this molecule in carcinogenesis and tumour progression, supporting HSP90 as a potential target for therapeutic intervention.

Synthesis, anticancer, and antibacterial activities of piplartine derivatives on cell cycle regulation and growth inhibition

A series of piplartine derivatives were synthesized via Baylis-Hillman reaction and evaluated for anticancer and antibacterial activities. The cytotoxicity of these compounds was examined in two different human tumor cell lines, IMR-32 and HeLa. The antibacterial activity was examined in Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that compounds 2b, 2e, and 2j were found to be the most active compounds, which displayed line no cytotoxicity, but G2-M cell cycle arrest in tumor cells, and showed cytostatic effects in bacteria.

Albumin precursor and Hsp70 modulate corneal wound healing in an organ culture model

In order to investigate the role of albumin precursor and Hsp70 in corneal wound healing, we have analyzed the distribution of these proteins in wounded and non-wounded corneas of rabbits and the effects of topical applications of anti-albumin precursor and anti-Hsp70 antibodies on wound healing. Anti-albumin precursor and anti-Hsp70 antibodies were topically applied in healing corneal epithelium of rabbit eyes in organ culture. Corneas were allowed to heal in vitro for up to 120 h in serum-free medium with 5 and 10 μg/ml or without (migrating control) anti-albumin precursor/ or anti-Hsp70 antibodies. Fibronectin (Fb) (5 μg/ml) was used as a positive control. Immunofluorescence labelling was used to detect proteins in corneal epithelium at various time intervals following an epithelial defect. Delay in wound healing (p<0.005) was observed with 10 μg/ml anti-albumin antibody labelling. A similar pattern was observed when anti-fibronectin antibody (5 μg/ml) alone and in combination with anti-albumin (10 μg/ml) was ectopically added with wound closure occurring at 120 h. However with anti-Hsp70 antibody (5 μg/ml) slightly delayed (p<0.005) wound closure was observed at 96 h and considerable retardation >120 h with 10 μg/ml. Additionally, immunofluoresence showed a strong co-localization of Hsp70 and albumin precursor during the active phase of wound healing. The presence of albumin precursor and Hsp70 in the epithelial compartment of the cornea indicates a role for these proteins in modulating cell behavior such as epithelial growth, adhesion or regeneration, thus contributing to corneal epithelial wound healing.

Downregulated expression of HSP27 in human low-grade glioma tissues discovered by a quantitative proteomic analysis

BACKGROUND

Heat shock proteins (HSPs), including mainly HSP110, HSP90, HSP70, HSP60 and small HSP families, are evolutionary conserved proteins involved in various cellular processes. Abnormal expression of HSPs has been detected in several tumor types, which indicates that specific HSPs have different prognostic significance for different tumors. In the current studies, the expression profiling of HSPs in human low-grade glioma tissues (HGTs) were investigated using a sensitive, accurate SILAC (stable isotope labeling with amino acids in cell culture)-based quantitative proteomic strategy.

RESULTS

The five HSP family members were detected and quantified in both HGTs and autologous para-cancerous brain tissues (PBTs) by the SILAC-based mass spectrometry (MS) simultaneously. HSP90 AB1, HSP A5(70 KDa), and especially HSP27 were significantly downregulated in HGTs, whereas the expression level of HSPA9 (70 KDa) was little higher in HGTs than that in PBTs. It was noted that the downregulation ratio of HSP27 was 0.48-fold in HGTs versus PBTs, which was further validated by results from RT-PCR, western blotting and immunohistochemistry. Furthermore, we detected HSP27 expression changes along with cell growth under heat shock treatment in glioma H4 cells.

CONCLUSION

The SILAC-MS technique is an applicable and efficient novel method, with a high-throughput manner, to quantitatively compare the relative expression level of HSPs in brain tumors. Different HSP family members have specific protein expression levels in human low-grade glioma discovered by SILAC-MS analysis. HSP27 expression was obviously downregulated in HGTs versus PBTs, and it exhibited temporal and spatial variation under heat shock treatment (43 degrees C/0-3 h) in vitro. HSP27's rapid upregulation was probably correlated with the temporary resistance to heat shock in order to maintain the survival of human glioma cells.

Diferuloylmethane augments the cytotoxic effects of piplartine isolated from Piper chaba

Natural compound based anticancer drug discovery is gaining interest against a wide variety of tumors. E-piplartine (trans-piplartine), a natural compound isolated from Piper chaba roots is examined against rat histiocytoma (BC-8), mouse embryonal carcinoma (PCC4), mouse macrophages (P388D1 and J774), and human neuroblastoma (IMR32) tumor cells. While Z-piplartine (cis-piplartine) failed to induce cytotoxicity (even at higher concentrations, 50 microM), E-piplartine induced a dose-dependent cytotoxicity (2-24 microM) in different tumor cells. The combinatorial treatment of piplartine with diferuloylmethane (curcumin), an anti-inflammatory and anticancer agent, significantly enhanced the piplartine induced cytotoxicity in tumor cells. Diferuloylmethane itself is not cytotoxic at 15 microM concentration; however, potentiated the piplartine induced cytotoxicity. The tumor cell killing with piplartine is preceded by G1 cell cycle arrest, and surpassed diferuloylmethane induced G2/M arrest when used in combination. In PCC4 cells, piplartine inhibited the cell cycle progression by inactivating cdk2 and destabilizing cyclin D1, whereas diferuloylmethane combination inhibited the ERK1/2 and Raf-1 signaling in addition to the inhibition of cell cycle progression. The over expression of heat shock protein 70, Hsp70 in rat histiocytic tumor cells interfered with piplartine induced cytotoxicity, hence, a cross talk between stress response and anticancer agents is presented. Our data demonstrates the biological and medicinal importance of piplartine isolated from the roots of P. chaba, and indicates that E-piplartine may be a promising candidate to use in combinatorial treatments to combat cancer.

Acute liver toxicity by carbon tetrachloride in HSP70 knock out mice

The effects of carbon tetrachloride (CCl(4)) treatment on acute liver damage in knock out (heat shock proteins -- HSP70-/-) mice and wild-type (C57BL/6) mice were examined. Acute liver injury was induced by a single intraperitoneal injection of 0.3 ML/kg CCl(4) in olive oil. Mice were sacrificed at 12, 24, 48 and 72 h after treatment. To assess hepatotoxicity, alanine transaminase, neutrophil infiltration and degree of necrosis were measured. Western blot analysis was employed for heat shock proteins. The result revealed that HSP70-/- mice showed higher alanine transaminase levels and a more severe degree of neutrophilic infiltration and necrosis than those of wild-type mice. Furthermore, HSP70-/- mice recovered more slowly from CCl(4) treatment. In HSP70-/- mice, HSP47 was overexpressed. Therefore, HSP70-/- mice could be an adequate model of acute liver toxicity study.

Overexpression of heat shock protein 27 is associated with good prognosis in the patient with oral squamous cell carcinoma

We investigated the expression and biological significance of heat shock protein (HSP)-27 in patients with oral squamous cell carcinoma (SCC). The expression of HSP-27 was quantified immunohistochemically in specimens from 37 patients with oral SCC. Findings were correlated with lymph node metastases, effect of chemotherapy, and survival. The presence of HSP-27 was identified in 31 of the 37 specimens (84%). Expression was low in 4 patients (11%), intermediate in 13 (35%), and high in 14 (38%). There were significant differences in the therapeutic effect of chemotherapy (Oboshi-Shimosato's grade) and prognosis in relation to expression of HSP-27. We found no correlation between the extent of expression of HSP-27 and stage or differentiation of the tumour.

Heat shock proteins and acute leukemias

Heat shock proteins (HSPs) acts as molecular chaperones by helping in the refolding of misfolded proteins and assisting in their elimination if they become irreversibly damaged. HSPs induced by stress treatment have a role in the modulation of apoptosis. The reduction in protein expression levels was correlated with an increased susceptibility to drug-induced apoptosis. HSPs have also been implicated in the resistance of leukemia cells to potential therapeutic agents. The mechanisms of cellular protection used by HSPs have yet to be fully defined. HSPs were shown highly expressed by acute myeloid leukemia (AML) cells as well as by acute lymphoblastic leukemia (ALL) cells. HSP expressions were correlated with that of differentiation antigens and that of drug-resistance and apoptosis proteins. Complete remission (CR) rates were higher in patients with lower expression of HSPs. Overall survival (OS) was significantly longer in patients with lower expression of HSPs. Therapeutically, inhibition of inducible HSP expression or activity should not cause any undesired side effects. HSPs emerge as novel therapeutic targets in anticancer protocols. Early results of phase I studies indicate that 17-allylamino-17-demethoxygeldamycin (17-AAG), capable of binding and disrupting the function of HSP90, results in an acceptable toxicity profile while achieving in vivo disruption of multiple oncogenic client proteins.

Heat shock proteins in the regulation of apoptosis: new strategies in tumor therapy: a comprehensive review

Heat shock proteins (Hsp) form the most ancient defense system in all living organisms on earth. These proteins act as molecular chaperones by helping in the refolding of misfolded proteins and assisting in their elimination if they become irreversibly damaged. Hsp interact with a number of cellular systems and form efficient cytoprotective mechanisms. However, in some cases, wherein it is better if the cell dies, there is no reason for any further defense. Programmed cell death is a widely conserved general phenomenon helping in many processes involving the reconstruction of multicellular organisms, as well as in the elimination of old or damaged cells. Here, we review some novel elements of the apoptotic process, such as its interrelationship with cellular senescence and necrosis, as well as bacterial apoptosis. We also give a survey of the most important elements of the apoptotic machinery and show the various modes of how Hsp interact with the apoptotic events in detail. We review caspase-independent apoptotic pathways and anoikis as well. Finally, we show the emerging variety of pharmacological interventions inhibiting or, just conversely, inducing Hsp and review the emergence of Hsp as novel therapeutic targets in anticancer protocols.

Hsp70 and Hsp90 change their expression and subcellular localization after microspore embryogenesis induction in Brassica napus L

A stress treatment of 32 degrees C for at least 8h was able to change the gametophytic program of the microspore, switching it to embryogenesis in Brassica napus, an interesting model for studying this process in vitro. After induction, some microspores started symmetric divisions and became haploid embryos after a few days, whereas other microspores, not sensitive to induction, followed their original gametophytic development. In this work the distribution and ultrastructural localization of two heat-shock proteins (Hsp70 and Hsp90) throughout key stages before and after embryogenesis induction were studied. Both Hsp proteins are rapidly induced, localizing in the nucleus and the cytoplasm. Immunogold labeling showed changes in the distribution patterns of these proteins, these changes being assessed by a quantitative analysis. Inside the nucleus, Hsp70 was found in association with RNP structures in the interchromatin region and in the nucleolus, whereas nuclear Hsp90 was mostly found in the interchromatin region. For Hsp70, the accumulation after the inductive treatment was accompanied by a reversible translocation from the cytoplasm to the nucleus, in both induced (embryogenic) and noninduced (gametophytic) microspores. However, the translocation was higher in embryogenic microspores, suggesting a possible additional role for Hsp70 in the switch to embryogenesis. In contrast, Hsp90 increase was similar in all microspores, occurring faster than for Hsp70 and suggesting a more specific role for Hsp90 in the stress response. Hsp70 and Hsp90 colocalized in clusters in the cytoplasm and the nucleus, but not in the nucleolus. Results indicated that stress proteins are involved in the process of microspore embryogenesis induction. The differential appearance and distribution of the two proteins and their association at specific stages have been determined between the two systems coexisting in the same culture: embryogenic development (induced cells) and development of gametes (noninduced cells).

Increased thermosensitivity of mouse colorectal carcinoma cells transfected with human FUT1 gene

The thermal responses of mouse colorectal carcinoma cells were investigated in the wild type cells and the transfected cells with human FUT1 gene which encodes alpha 1,2fucosyltransferase. The heat sensitivity was observed to increase in the FUT1 gene transfected cells and the effect of hyperthermia at 44 degrees C on these cells was demonstrated to be significant (P<0.001) to the wild type cells even though no remarkable difference in the expression of the heat shock protein, Hsp70 was found in these cells. Thus the expression of alpha 1,2fucosylated antigens seemed to increase the heat sensitivity in mouse colorectal carcinoma cells.

Induction of heat shock protein 47 synthesis by TGF-beta and IL-1 beta via enhancement of the heat shock element binding activity of heat shock transcription factor 1

With most immunological reactions, tissue fibrosis, collagen overproduction caused by immune cytokines, is inevitably associated. Among the various immune cytokines, heat shock protein 47 (HSP47) is a procollagen-specific molecular chaperon and is essential for secretion of procollagen from cells. Induction of HSP47 by TGF-beta has been previously reported in rat skeletal myoblasts and mouse osteoblasts, but not in human diploid fibroblasts. As for IL-1beta, its effect on HSP47 has not been elucidated. In the present study, using human embryonic lung fibroblast cells, we first disclosed that both TGF-beta and IL-1beta induced HSP47 synthesis. We then revealed that the binding of the heat shock element (HSE) by heat shock transcription factor 1 (HSF1) was enhanced by both cytokines. We further demonstrated that trimer formation of HSF1, which is essential for its binding to HSE, was induced by these cytokines. The enhancement of HSP47 synthesis and their trimer formation of HSF1 were augmented by using a combination of both cytokines. Collectively, TGF- beta and IL-1beta were found to induce trimer formation of HSF1 which in turn bound to HSE of HSP47, resulting in the enhancement of HSP47 expression. Thus, HSP47 could well be a good candidate for molecular targeting in controlling tissue fibrosis, given that both principal fibrinogenetic cytokines (TGF-beta, IL-1beta) are commonly involved in its induction through HSF1 trimerization.

HSP70 is selectively over-expressed in the blast cells of the germinal centres and paracortex in reactive lymph nodes

AIMS

We evaluated by immunohistochemistry HSP70 expression in reactive lymph nodes since its morphological expression and location have not been previously described and correlated with lymphocyte kinetics.

METHODS AND RESULTS

Ninety-six cases of non-specific lymphadenitis were immunostained for HSP70, CD20, CD3, Ki67, Bcl-2, CD21. The type and the location of HSP70-positive cells were determined. Their number out of 2000 cells in each germinal centre and in each paracortical area was counted at 60x magnification with the help of a quantitative grid. Seventeen percent of germinal centre cells and 7.6% of the paracortex cells were positive. This difference was highly significant. The positively reacting cells were B-cells and had a blast (centroblast or immunoblast) morphology, with negative mantle and marginal lymphocytes and T-cells. Lymphoplasmacytoid cells and plasma cells reacted only weakly or were negative. Germinal centre antigen-presenting cells and interdigitating dendritic cells reacted from lightly to moderately.

CONCLUSIONS

HSP70 was selectively over-expressed by B-blasts mainly located within germinal centres with a lower number in the paracortex. The difference in the mean number between the two sites was statistically highly significant. No correlation was found with bcl-2 and Ki67 expression. Mantle, marginal and T-lymphocytes were always negative. The biological meaning and role of this over-expression in centroblasts and immunoblasts remain to be elucidated.

Over-expression of heat shock proteins in carcinogenic endometrium

We have previously shown that the subcellular localization of beta-catenin changes according to the cell proliferation status of the human endometrium, suggesting a role of intercellular transduction in cell growth control in human endometrium not only in the physiological but also in the carcinogenic condition. To further study the possible role of heat shock proteins (HSPs) in growth control, we immunohistochemically analyzed 92 endometrial samples, 30 of normal endometrium, 20 of endometrial hyperplasia and 42 of endometrial cancer, for expression of HSP27, HSP70, HSP90, estrogen receptor (ER) and progesterone receptor. HSP27 and HSP90 were detected in endometrial epithelium strongly in the proliferative phase and weakly in the secretory phase during the menstrual cycle according to the serum estradiol level. However, they were over-expressed in endometrial hyperplasia, especially HSP27. In endometrial cancer, HSP27 expression was heterogenic among the glands and lower than that in the proliferative phase and endometrial hyperplasia. HSP27 over-expression was also observed in samples including endometrial cancer and associated hyperplasia. Results of Western blotting followed those of immunohistochemistry. HSP70 was not changed during the menstrual cycle, as HSP27 and HSP90 were, and was rather stably expressed in endometrial hyperplasia and cancer. Our results suggest that HSP27 and HSP90 contribute to cell proliferation in endometrial epithelium and that over-expression of HSP27 in endometrial hyperplasia occurs as a result of the activated condition of ER, though in cancer it decreases according to the loss of function of ER.

The proliferative response of isolated human tendon fibroblasts to cyclic biaxial mechanical strain

At the cellular level, dynamic strain plays a key role in cell stimulation and organization of the extracellular matrix. Although positive effects of physical strain on tendon tissue are well known, little knowledge exists on how mechanical strain affects tendon cells. In this study, human tendon fibroblasts from patellar tendon were cultured on silicone dishes. Subsequently, cyclic biaxial mechanical strain was applied to the dishes for 15, 30, and 60 minutes using a specially developed cell stretching system. After the fibroblasts were strained, cells were tested for proliferation at 6, 12, and 24 hours. As a control, cells were grown on silicone dishes but did not receive any strain. A biphasic response in proliferation was observed for the 15- and 60-minute strain periods: at 6 hours and 24 hours there was more proliferation than at 12 hours. After a strain duration time of 30 minutes, a lower proliferation rate was measured compared with control levels. This study shows that application of mechanical stress to tendon fibroblasts resulted in an alteration of cellular proliferation depending on the stress time. Our results may implicate future modifications in the treatment of ligament and tendon injuries.

Basal synthesis of heat shock protein 70 increases with age in rat kidneys

The heat shock protein (HSP) system is a mechanism of cell defense induced by stress, constitutively expressed during basal conditions and essential to the maintenance of cellular integrity. Acutely induced HSP synthesis decreases with aging, but the effect of age on the basal expression of HSP70 has not been specifically addressed so far. The aim of this work is to study the age-dependent basal concentrations of HSP70 mRNA in rat kidneys. In 8 young (2-3 months), 6 adult (6-11 months) and 6 old male Wistar rats (22-27 months), steady-state concentrations of HSP70 and gamma-actin mRNA and of rRNA were measured. Pentosidine was measured by HPLC. The basal, unstimulated HSP70 mRNA is increased in young and old rats compared with adult subjects [young: 182% of adult levels (100-299), old: 167% of adults (142-209); p < 0.005]. The amount of pentosidine increases with age (young: 0.6 +/- 0.1; adult: 1.65 +/- 0.15; old: 2.3 +/- 0.3 pmol/mg of protein; p < 0.0001). It seems likely that different mechanisms are responsible for the increased HSP70 basal synthesis in both the young and old animals. The prevalence of anabolic activity can trigger the increased basal production of HSP70 in young rats. The accumulation of posttranslational modified proteins, documented by pentosidine, can chronically enhance HSP70 synthesis in aged animals. The suppression of the synthesis of other proteins accompanying HSP-selective production might contribute to the impairment of specific cell functions in aging.

Inhibition of src family kinases by a combinatorial action of 5'-AMP and small heat shock proteins, identified from the adult heart

Src family kinases are implicated in cellular proliferation and transformation. Terminally differentiated myocytes have lost the ability to proliferate, indicating the existence of a down-regulatory mechanism(s) for these mitogenic kinases. Here we show that feline cardiomyocyte lysate contains thermostable components that inhibit c-Src kinase in vitro. This inhibitory activity, present predominantly in heart tissue, involves two components acting combinatorially. After purification by sequential chromatography, one component was identified by mass and nuclear magnetic resonance spectroscopies as 5'-AMP, while the other was identified by peptide sequencing as a small heat shock protein (sHSP). 5'-AMP and to a lesser extent 5'-ADP inhibit c-Src when combined with either HSP-27 or HSP-32. Other HSPs, including alphaB-crystallin, HSP-70, and HSP-90, did not exhibit this effect. The inhibition, observed preferentially on Src family kinases and independent of the Src tyrosine phosphorylation state, occurs via a direct interaction of the c-Src catalytic domain with the inhibitory components. Our study indicates that sHSPs increase the affinity of 5'-AMP for the c-Src ATP binding site, thereby facilitating the inhibition. In vivo, elevation of ATP levels in the cardiomyocytes results in the tyrosine phosphorylation of cellular proteins including c-Src at the activatory site, and this effect is blocked when the 5'-AMP concentration is raised. Thus, this study reveals a novel role for sHSPs and 5'-AMP in the regulation of Src family kinases, presumably for the maintenance of the terminally differentiated state.

Expression of 90-kDa heat shock protein within regenerative tubular cells in a patient with acute oliguric renal failure due to malignant hypertension

A 29-year-old man developed acute oliguric renal failure with severe hypertension and microangiopathy. He was treated with hemodialysis and anti-hypertensive drugs, but oliguria was prolonged. A renal biopsy was performed on the 29th hospital day. Small arteries and arterioles were characterized by marked intimal thickening, and most of the glomeruli showed ischemic changes. Although there was extensive tubular loss and atrophy, regenerative changes were occasionally observed in some tubules, in which 90-kDa heat-shock protein was induced. He was diagnosed as having malignant nephrosclerosis, and was treated with a prostaglandin I2 analog, in addition to anti-hypertensive drugs. Thereafter, his renal function recovered gradually, and hemodialysis was discontinued on the 49th hospital day. Functional recovery lasts more than five years. We suggest that the expression of HSP90 in regenerative tubular cells is a useful histological indicator for predicting recovery from acute oliguric renal failure due to malignant hypertension.

Heat shock and apoptosis. The two defense systems of the organism may have overlapping molecular elements

Stress response and apoptosis are two interrelated end points of the defense systems of living organisms. The molecular elements of the two have strong influences on each other. Ceramide formation and signal-induced phosphorylation cascades may be critical in determining the final fate of cells exposed to environmental changes.

Heat shock protein and p53 expression in head and neck squamous cell carcinoma

BACKGROUND

Heat shock proteins have been associated with the mutant form of the tumor suppressor gene, TP53, and with resistance to cancer chemotherapy.

METHODS

Archival tissues from 50 patients with head and neck squamous cell carcinoma who received primary surgical resection were examined for p53, HSP27, and HSP70 by immunohistochemistry and correlated with tumor stage, grade, and 5-year survival (alive or deceased).

RESULTS

Both heat shock proteins were strongly expressed in normal mucosa and in small (T1 and T2) tumors. Thirty (60%) of tumors were positive for p53, 43 (86%) for HSP27, and 34 (68%) for HSP70, with no association between p53 and heat shock protein expression. Twenty-five patients were alive (4 with disease), and 25 patients were deceased (9 from other causes). p53 Protein overexpression correlated with low-grade tumors. Only primary tumor site (i.e., oral cavity > larynx > oropharynx/base of tongue) and N stage were significantly associated with survival.

CONCLUSIONS

Heat shock proteins are expressed in normal upper respiratory tract squamous mucosa, and their role in carcinoma remains unclear. None of the markers, p53, HSP27, or HSP70, demonstrated prognostic significance for 5-year survival. We confirm the recognized association of cervical lymph node metastases with decreased survival.

Epithelial cell proliferation in the digestive tract induced by space restriction and water-immersion stress

The effects of space restriction and water-immersion stress on epithelial cell proliferation in the digestive tract, with special attention to the esophagus, stomach and duodenum, in 8-week-old SD male rats were examined. Histological assessment revealed spotted hemorrhagic lesions in the fundus of the glandular stomach, accompanied by statistically increased 5-bromo-2'-deoxyuridine (BrdU) labeling index in the fundic and pyloric regions. Furthermore, biochemical analysis demonstrated an increased activity of ornithine decarboxylase (ODC) and spermidine/spermine N1-acetyltransferase (SAT), known as key late-limiting enzymes of the polyamine pathway, in the gastric fundus. The stress may induce a remarkable increase in expression of c-fos, c-jun and c-myc mRNAs in both fundic and pyloric regions of the glandular stomach. There were no remarkable changes in the esophagus. These results indicate that space restriction and water-immersion stress induced cell proliferation in the glandular stomach through overexpression of proto-oncogenes and increased ODC and SAT activities that might be related to the promotion of gastric carcinogenesis.

Expression of heat shock proteins in squamous cell carcinoma of the tongue: an immunohistochemical study

Twenty-four specimens of squamous cell carcinoma of the tongue were immunostained for heat shock proteins (HSPs) to reveal differences in stainability among normal epithelium, dysplasia and carcinoma and to clarify the prognostic significance of HSPs in comparison with survival period, clinical stage, lymph node metastasis, histological grade, and p53 immunostaining. Normal epithelium was positively stained in the suprabasal layer for HSP60 and HSP70, but was negative for HSP27 and HSP90. Dysplastic lesions were positive for HSP27, HSP70 and HSP90, but stained variously for HSP60. In squamous cell carcinoma, the cytoplasm of suprabasal tumor cells was often positive for HSP27 and HSP90 (18/24, 17/24, respectively). Although HSP immunohistochemistry has revealed changes in HSP expression during tumorigenesis of squamous epithelium of the tongue, there was no correlation between HSP staining and survival period, stage, lymph node metastasis, histological grade or p53 immunostaining.

Nuclear translocation of constitutive heat shock protein 70 during S phase in synchronous macroplasmodia of Physarum polycephalum

The level of constitutive heat shock protein 70 (HSC70) in Physarum polycephalum was analyzed by means of Western blots during the synchronous cell cycle of macroplasmodia. Total amounts as well as nuclear and cytoplasmic contents were determined separately and evaluated densitometrically. A drastic increase of nuclear HSC70 was observed 10-40 min after the initiation of S phase (600% of the M phase value) and thereafter a slow decline toward the next M phase. Total HSC levels showed a slight (30%) increase during S phase whereas cytoplasmic HSC70 was about 30% lower during S phase compared to mitosis.

Expression of hsc 70, but not hsp 70, in human third molar dental pulp

The constitutive (hsc 70) and inducible (hsp 70) isoforms of heat shock protein 70 are important members of the superfamily of stress related proteins that protect and promote the recovery of cells from physiological and pathologic stress. The goal of this study was to define the baseline expression of hsc 70 and hsp 70 in disease-free, minimally stressed human dental pulp of the adult 3rd molar. Immunolocalization demonstrated moderate to heavy staining intensity for hsc 70 in both the cytoplasm and nucleus of odontoblasts and fibroblasts comprising the human pulp. Endothelial and smooth muscle cells displayed weak to moderate immunoreactivity for hsc 70 in both the cytoplasm and nucleus. Schwann cells demonstrated only weak nuclear staining for hsc 70. No immunoreactivity for hsp 70 was observed in any cell type in human pulp. Western, northern, and RT-PCR analysis of pulp preparations confirmed the expression of hsc 70 mRNA and protein within components of the pulp. These results demonstrate that cells of the human pulp express, under conditions of minimal stimulation, a key component of the stress response protein superfamily. The expression of hsc 70 under conditions of minimal stress may provide pulp components an advantage in resisting cell injury when stress occurs.

Stress-response proteins in human pituitary adenomas. Expression of heat-shock protein 72 (HSP-72)

The presence of heat-shock protein 72 (HSP-72) was investigated by immunohistochemistry (IHC) in a series of 28 surgically removed pituitary adenomas including six somatotroph, two mammosomatotroph, five lactotroph, six corticotroph, four null cell adenomas, and three oncocytomas. Overall, 25 tumors (90%) were positive for HSP-72. One somatotroph, one lactotroph, and one null cell adenomas each contained only sparse, small HSP-72 immunoreactive granules and were regarded as negative. The expression of HSP-72 was commonly uneven differing in degree from cell to cell and among various tumors. In most adenomas, the immunoreactivity was seen as fine granules of moderate density, distributed throughout the cytoplasm. In some cells, the immunoreactivity was strong and diffuse. In one somatotroph, two corticotroph, one null cell, and one oncocytic adenomas, nearly all tumor cells were strongly positive. Adenoma cells, located adjacent to capillaries and small vessels, commonly showed a selective and strong immunoreactivity for HSP-72. The fragments of nontumorous adenohypophysial parenchyma also contained fine immunoreactive cytoplasmic granules accumulating in scattered hormone-producing cells in stellate cells. These results show that HSP-72 is expressed in most pituitary adenomas with a mostly focal and less frequently diffuse pattern of overexpression.

Thapsigargin induces phosphorylation of the 27-kDa heat shock protein in human keratinocytes

In the human keratinocyte line HaCaT, the nonphosphorylated 27-kDa heat shock protein (HSP27) isoform A (pI 6.5) is constitutively expressed. Application of thapsigargin, which inhibits Ca2+-ATPase in the endoplasmic reticulum, results in the rapid formation of the phosphorylated HSP27 isoform B (pI 6.0) and reduction of HSP27 A without affecting the synthesis of HSP27. The thapsigargin-dependent HSP27 isoform change is similar to that induced by 43 degrees C heat shock, but different from that induced by arsenite, where the biphosphorylated isoform HSP27 C (pI 5.7) is observed. The receptor agonist bradykinin, which increases intracellular Ca2+ (Ca(i)) level, shows no effect on the distribution of HSP27 isoforms. The responses of HSP27 isoforms to thapsigargin are independent of Ca(i) concentration in HaCaT cells. These observations suggest that the thapsigargin-induced change in HSP27 isoforms is dependent on the depletion of internal Ca2+ stores rather than on the increase in Ca(i) concentration. The thapsigargin-induced change in HSP27 isoforms is reduced by the tyrosine kinase inhibitor, genistein, but not the protein kinase C inhibitor, H-7. We propose that the modulation of HSP27 phosphorylation status by Ca(i) homeostasis may be mechanistically linked to control of keratinocyte growth and differentiation and responses of keratinocytes to extracellular stresses.