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Inflammatory bowel disease (IBD) encompasses various pathological conditions similar but distinct that share a multifactorial etiology, including involvement of the intestinal barrier function, the immune system, and intestinal microorganisms. Hsp60 is a chaperonin component of the chaperoning system, present in all cells and tissues, including the intestine. It plays important roles in cell physiology outside and inside mitochondria, its canonical place of residence. However, Hsp60 can also be pathogenic in many conditions, the Hsp60 chaperonopathies, possibly including IBD. The various clinico-pathological types of IBD have a complicated mix of causative factors, among which Hsp60 can be considered a putatively important driver of events and could play an etiopathogenic role. This possibility is discussed in this review. We also indicate that Hsp60 can be a biomarker useful in disease diagnosing and monitoring and, if found active in pathogenesis, should become a target for developing new therapies. The latter are particularly needed to alleviate patient suffering and to prevent complications, including colon cancer.

The effect of supraoptimal concentrations of ammonia on cell growth and stress genes of the dnaK locus was investigated in Methanosarcina mazei S-6, a methanogen important for anaerobic digestion in bioreactors. When the concentration of NH4Cl was increased 25 times above the optimal for growth, the lag phase lengthened, growth occurred at a decreased rate, and a stress response was induced – the transcripts from the stress genes grpE, dnaK, and dnaJ increased, whereas that of the adjacent genes orf11-trkA decreased. In contrast, a 10-fold elevation of the NH4Cl concentration, which had only a slight stimulating effect on the stress genes, augmented the orf11-trkA transcript. These findings show that ammonia at certain levels is a cell stressor for M. mazei S-6.

The molecular chaperones Hsp60 and Hsp10 are, according to recent reports, involved in cancer development and progression. We, for instance, have found that their expression varies with distinctive patterns in different malignancies: they are overexpressed in colorectal, exocervical and prostate carcinogenesis, and colorectal cancer progression, but they are downregulated during bronchial carcinogenesis. There is also evidence showing that Hsp60 and Hsp10 can be used as therapeutic agents, for example in rheumatoid arthritis. In view of these findings we want now to call attention to the potential of Hsp60 and Hsp10 in cancer therapy.

Heat shock proteins (Hsps) are produced in response to various stressors, including ischemia-reperfusion, and they can exit cells and reach the blood. In this pilot study, we determined serum levels of Hsp60 and heme-oxygenase-1 (HO-1; also named Hsp32) in subjects with acute myocardial infarction (AMI) to assess their clinical significance and potential prognostic value. We also performed a bioinformatics analysis of the 2 molecules in search of structural clues on the mechanism of their release from cells. We studied 40 patients consecutively admitted for AMI (male:female patient ratio = 20:20, mean age: 64 ± 13 years) and 40 matched controls. A blood sample was drawn for biochemical analyses within 24 h of symptoms onset, and Hsp60 and HO-1 concentrations were determined by enzyme-linked immunosorbent assay (ELISA). All patients were followed up for 6 months to register adverse post-AMI cardiovascular events. A multivariate analysis demonstrated that elevated Hsp60 (P = 0.0361), creatine phosphokinase-muscle brain (CK-MB) (P = 0.0446), and troponin (P = 0.0490) were predictive of post-AMI adverse events. In contrast, increased HO-1 showed a significant association with less severity of coronary artery diseases (P = 0.0223). These findings suggest that Hsp60 and HO-1 play distinct roles in the pathogenesis of AMI and subsequent AMI-related pathology. The possibility that these proteins differ in their roles and mechanisms of action in AMI and post-AMI pathology was supported also by the bioinformatics estimates of probability of their localization in various subcellular compartments. The results clear the way for subsequent investigation on the pathogenetic role and clinical significance of Hsp60 and HO-1 in AMI.

Background Hsp60, a Group I mitochondrial chaperonin, is classically considered an intracellular chaperone with residence in the mitochondria; nonetheless, in the last few years it has been found extracellularly as well as in the cell membrane. Important questions remain pertaining to extracellular Hsp60 such as how generalized is its occurrence outside cells, what are its extracellular functions and the translocation mechanisms that transport the chaperone outside of the cell. These questions are particularly relevant for cancer biology since it is believed that extracellular chaperones, like Hsp70, may play an active role in tumor growth and dissemination. Methodology/Principal Findings Since cancer cells may undergo necrosis and apoptosis, it could be possible that extracellular Hsps are chiefly the result of cell destruction but not the product of an active, physiological process. In this work, we studied three tumor cells lines and found that they all release Hsp60 into the culture media by an active mechanism independently of cell death. Biochemical analyses of one of the cell lines revealed that Hsp60 secretion was significantly reduced, by inhibitors of exosomes and lipid rafts. Conclusions/Significance Our data suggest that Hsp60 release is the result of an active secretion mechanism and, since extracellular release of the chaperone was demonstrated in all tumor cell lines investigated, our observations most likely reflect a general physiological phenomenon, occurring in many tumors.

HSP and molecular chaperones, both referred to in this chapter as chaperones, are key players in development and senescence. With regard to senescence, several issues are critical: the role of normal chaperones in the process of ageing itself and in preventing and controlling age-associated diseases, the role of defective chaperones (chaperonopathies) in the onset and progression of senescence and in the etiology of old-age diseases, the interaction of chaperones with the immune system, and the potential of chaperones as therapeutic agents for counteracting the deleterious effects of ageing on molecules and cells and for treating proteinopathies of the elderly (chaperonotherapy). All these issues are discussed in this chapter, focusing on Hsp60 and Hsp10 (referred to as chaperonins for the purposes of this article) by examining a sample of publications dealing with pathological conditions prevalent in aged individuals, such as atherosclerosis and coronary syndromes, neurodegenerative and degenerative joint disorders, diabetes, chronic occlusive pulmonary disease, and glaucoma (cancer is omitted because it has recently been extensively discussed elsewhere). The data show that Hsp60 and Hsp10 undergo changes in levels and distribution inside cells and tissues, including invasion of the extracellular space and plasma, with age and health status and in relation with specific pathologies. The physiological and/or pathological significance of these changes is not yet fully understood but is being actively investigated. The role of chaperonopathies, particularly those due to aberrant post-translational modifications related to stressors such as ROS, on the aggravation of senescence ought to be examined in detail in the near future. Studies on the mechanisms by which defective chaperones (molecular chaperonopathies) accelerate senescence and contribute to pathogenesis and, thus, to the development of disease (clinical chaperonopathies) should provide key information useful for developing diagnostic and therapeutic means based on chaperone genes and proteins

This article is about Hsp10 and its intracellular and extracellular forms focusing on the relationship of the latter with Early Pregnancy Factor and on their roles in cancer and immunity. Cellular physiology and survival are finely regulated and depend on the correct functioning of the entire set of proteins. Misfolded or unfolded proteins can cause deleterious effects and even cell death. The chaperonins Hsp10 and Hsp60 act together inside the mitochondria to assist protein folding. Recent studies demonstrated that these proteins have other roles inside and outside the cell, either together or independently of each other. For example, Hsp10 was found increased in the cytosol of different tumors (although in other tumors it was found decreased). Moreover, Hsp10 localizes extracellularly during pregnancy and is often indicated as Early Pregnancy Factor (EPF), which is released during the first stages of gestation and is involved in the establishment of pregnancy. Various reports show that extracellular Hsp10 and EPF modulate certain aspects of the immune response with anti-inflammatory effects in patients with autoimmune conditions improving clinically after treatment with recombinant Hsp10. Moreover, Hsp10 and EPF are involved in embryonic development, acting as a growth factor, and in cell proliferation/differentiation mechanisms. Therefore, it becomes evident that Hsp10 is not only a co-chaperonin, but an active player in its own right in various cellular functions. In this article, we present an overview of various aspects of Hsp10 and EPF as they participate in physiological and pathological processes such as the antitumor response and autoimmune diseases.

Different degenerative diseases of the central nervous system (CNS) appear after middle age, and increase in frequency in the elderly. They seem to be associated with aging. Data suggest that while aging is partly dictated by genetic determinants, environmental stressors also play a role. Normal aging and a decrease in the capacity to mount a stress response go in parallel. Conversely, genetic conditions that confer longevity are accompanied by improved capacity to respond to stressors. Stress proteins and molecular chaperones are the typical manifestations of the stress response. They play a key role in peptide folding and trafficking, and thus maintain the normal cellular set of protein molecules in their native (functional) configuration. This set of proteins enables the cell to function and to survive stressful situations. Due to gene mutations, defective peptides may appear that have a tendency to misfold and form deposits in vital tissues, e.g., those of the CNS, a condition that is usually associated with degenerative diseases. It remains to be determined how much stress proteins and molecular chaperones participate in the aging process, and in the pathogenesis of the degenerative diseases accompanying this process in many individuals. Because of the known role of chaperones in maintaining the normal set of proteins in a functional configuration, one might assume that chaperones are key players in pathogenesis. Chaperones may prevent protein misfolding, and aggregation, and may mediate dissolution of protein deposits. Likewise, chaperones may become trapped in protein aggregates when they bind defective peptides but cannot assist in their correct folding, or cannot release them, owing to a defect in the pathologic peptide. This entrapment is suggested by the presence of chaperones in pathologic protein deposits. The cell's protein balance also depends on degradation. One might say that the normal set of proteins in a cell is maintained by generation of new molecules and, at the other end of the pathway, by proteolysis. Old, damaged, proteins are eliminated by proteolytic systems, and the same may happen to defective peptides due to gene mutations if they cannot be driven by chaperones into the functional pool. Arguably, molecular chaperones are in the central, most critical, portion of the protein assembly line. They play a crucial role as they assist in the correct folding of new peptides, or present those destined for degradation to proteases. Protein deposits in degenerative diseases may be due not only to a failure of the folding mechanism, but also to a failure of the proteolytic system. Participation of the latter is evidenced by the presence of some of its components (e.g., ubiquitin) in the pathologic protein deposits. Future research aiming at elucidating the role of chaperones in degenerative diseases, whether as pathogenetic factors or preventive-curative tools, ought to explore a number of possibilities. For example, folding of mutant peptides ought to be assessed in vivo and in vitro . One will have to take into account that chaperones function as complex machines and interact with other molecules and structures. Information from comparative analyses of gene, protein, and genome sequences should help in the selection of experimental systems and molecular targets for investigation. The effect of stressors with which humans are confronted daily, ought to be measured to assess their role on peptide misfolding and aggregation, and in disease onset and progression in individuals genetically susceptible to degenerative diseases. One might argue that the presence of a defective peptide requires the chaperone system constantly. When a stressor hits the cell, the chaperone system is partly diverted to protect and rescue normal peptides damaged by stress and must abandon some copies of the defective peptide. These “unprotected” copies misfold and precipitate. Stress would thus play a critical role in disease onset and progression by creating a functional overload to the chaperone system, already overextended because of the presence of the mutant peptide.

The use of antibodies as molecular probes for microbes and their antigens has a long tradition [19,23,24]. Poly- and monoclonal antibody probes have been used for microbial identification, characterization, classification, quantification, and manipulation for many years. The development of the enzyme-linked immunosorbent assay (ELISA) [8] has made the use of antibody probes in microbiology and microbial ecology popular and rewarding. The quantitative slide immunoenzymatic assay (SIA) [6] is a miniature ELISA with specific advantages and applications. SIA is simple, sensitive, and versatile [2,3,18], provides reproducible results, and can be automated, (Fig.1) [2,4]. SIA technology can be used for a variety of purposes [1,2,9,18,22–24]. These include identification and quantification of microbes in axenic cultures, in mixed cultures, and in complex microbial communities [4,6,7,14–16,24]. For these purposes, SIA can be used alone or in combination with immunofluorescence and other techniques [14]. SIA allows also detection and quantification of soluble and micro-particulate antigens secreted or released by microbes (microbial footprints as it were) into the culture medium, or into the environment (water and soil, for example) [2–4,6,7,23]. More recently, SIA technology has been adapted for molecular biology, to detect bacteria by nucleic-acid hybridization [5].

Chlamydia trachomatis (CT) infection is one of the most common causes of reproductive tract diseases and infertility. CT-Hsp60 is synthesized during infection and is released in the bloodstream. As a consequence, immune cells will produce anti-CT-Hsp60 antibodies. Hsp60, a ubiquitous and evolutionarily conserved chaperonin, is normally sequestered inside the cell, particularly into mitochondria. However, upon cell stress, as well as during carcinogenesis, the chaperonin becomes exposed on the cell surface (sf-Hsp60) and/or is secreted from cells into the extracellular space and circulation. Reports in the literature on circulating Hsp and anti-Hsp antibodies are in many cases short on details about Hsp60 concentrations, and about the specificity spectra of the antibodies, their titers, and their true, direct, pathogenetic effects. Thus, more studies are still needed to obtain a definitive picture on these matters. Nevertheless, the information already available indicates that the concurrence of persistent CT infection and appearance of sf-Hsp60 can promote an autoimmune aggression towards stressed cells and the development of diseases such as autoimmune arthritis, multiple sclerosis, atherosclerosis, vasculitis, diabetes, and thyroiditis, among others. At the same time, immunocomplexes composed of anti-CT-Hsp60 antibodies and circulating Hsp60 (both CT and human) may form deposits in several anatomical locations, e.g., at the glomerular basal membrane. The opposite side of the coin is that pre-tumor and tumor cells with sf-Hsp60 can be destroyed with participation of the anti-Hsp60 antibody, thus stopping cancer progression before it is even noticed by the patient or physician.

We have cultivated lymph node microfragments from ß-D-galactosidase (Escherichia coli) primed rabbits and have measured their secondary response directed towards the whole molecule (precipitating antibodies) and to a single determinant (activating antibodies) of the antigen. By decreasing the size of the fragments to 105 cells, we began to observe heterogeneity among identical cultures in terms of positivity of response, antibody specificity, and titers. The affinity of "early" activating antibodies was inversely proportional to the dose of challenge. While no maturation was seen in low and excessive challenge, in all cultures receiving intermediate doses the association constant was raised several orders of magnitude within periods of 20 days. The relevance of these data to the mechanism of affinity selection of antigen-sensitive cells is discussed.

MORPHOLOGICAL variations in the human eosinophil granule under electron microscopic examination have been recently recorded1. Furthermore, other variations in the eosinophil granule have been described before1. In fact, it seems probable that there are two or more different populations of granules.

Hsp70s are chaperone proteins that are conserved in evolution and present in all prokaryotic and eukaryotic organisms. In the archaea, which form a distinct kingdom, the Hsp70 chaperones have been found in some species only, including Methanosarcina mazei. Both the bacterial and archaeal Hsp70(DnaK) chaperones cooperate with a GrpE co-chaperone which stimulates the ATPase activity of the DnaK protein. It is currently believed that the archaeal Hsp70 system was obtained by the lateral transfer of chaperone genes from bacteria. Our previous finding that the DnaK and GrpE proteins of M. mazei can functionally cooperate with the Escherichia coli GrpE and DnaK supported this hypothesis. However, the cooperation was surprising, considering the very low identity of the GrpE proteins (26%) and the relatively low identity of the DnaK proteins (56%). The aim of this work was to investigate the molecular basis of the observed interspecies chaperone interaction. Infrared resolution-enhanced spectra of the M. mazei and E. coli DnaK proteins were almost identical, indicating high similarity of their secondary structures, however, some small differences in band position and in the intensity of amide I' band components were observed and discussed. Profiles of thermal denaturation of both proteins were similar, although they indicated a higher thermostability of the M. mazei DnaK compared to the E. coli DnaK. Electrophoresis under non-denaturing conditions demonstrated that purified DnaK and GrpE of E. coli and M. mazei formed mixed complexes. Protein modeling revealed high similarity of the 3-dimensional structures of the archaeal and bacterial DnaK and GrpE proteins.

Gliomas have poor prognosis no matter the treatment applied, remaining an unmet clinical need. As background for a substantial change in this situation, this review will focus on the following points: (i) the steady progress in establishing the role of molecular chaperones in carcinogenesis; (ii) the recent advances in the knowledge of miRNAs in regulating gene expression, including genes involved in carcinogenesis and genes encoding chaperones; and (iii) the findings about exosomes and their cargo released by tumor cells. We would like to trigger a discussion about the involvement of exosomal chaperones and miRNAs in gliomagenesis. Chaperones may be either targets for therapy, due to their tumor-promoting activity, or therapeutic agents, due to their antitumor growth activity. Thus, chaperones may well represent a Janus-faced approach against tumors. This review focuses on extracellular chaperones as part of exosomes’ cargo, because of their potential as a new tool for the diagnosis and management of gliomas. Moreover, since exosomes transport chaperones and miRNAs (the latter possibly related to chaperone gene expression in the recipient cell), and probably deliver their cargo in the recipient cells, a new area of investigation is now open, which is bound to generate significant advances in the understanding and treatment of gliomas.