[Show abstract][Hide abstract] ABSTRACT: The mitochondrial chaperonin Hsp60 is a ubiquitous molecule with multiple roles, constitutively expressed and inducible by oxidative stress. In the brain, Hsp60 is widely distributed and has been implicated in neurological disorders, including epilepsy. A role for mitochondria and oxidative stress has been proposed in epileptogenesis of temporal lobe epilepsy (TLE). Here, we investigated the involvement of Hsp60 in TLE using animal and human samples. Hsp60 immunoreactivity in the hippocampus, measured by Western blotting and immunohistochemistry, was increased in a rat model of TLE. Hsp60 was also increased in the hippocampal dentate gyrus neurons somata and neuropil and hippocampus proper (CA3, CA1) of the epileptic rats. We also determined the circulating levels of Hsp60 in epileptic animals and TLE patients using ELISA. The epileptic rats showed circulating levels of Hsp60 higher than controls. Likewise, plasma post-seizure Hsp60 levels in patients were higher than before the seizure and those of controls. These results demonstrate that Hsp60 is increased in both animals and patients with TLE in affected tissues, and in plasma in response to epileptic seizures, and point to it as biomarker of hippocampal stress potentially useful for diagnosis and patient management.
[Show abstract][Hide abstract] ABSTRACT: The pathogenesis of Hashimoto's thyroiditis includes autoimmunity involving thyroid antigens, autoantibodies, and possibly cytokines. It is unclear what role plays Hsp60, but our recent data indicate that it may contribute to pathogenesis as an autoantigen. Its role in the induction of cytokine production, pro- or anti-inflammatory, was not elucidated, except that we found that peripheral blood mononucleated cells (PBMC) from patients or from healthy controls did not respond with cytokine production upon stimulation by Hsp60 in vitro with patterns that would differentiate patients from controls with statistical significance. This "negative" outcome appeared when the data were pooled and analyzed with conventional statistical methods. We re-analyzed our data with non-conventional statistical methods based on data mining using the classification and regression tree learning algorithm and clustering methodology. The results indicate that by focusing on IFN-γ and IL-2 levels before and after Hsp60 stimulation of PBMC in each patient, it is possible to differentiate patients from controls. A major general conclusion is that when trying to identify disease markers such as levels of cytokines and Hsp60, reference to standards obtained from pooled data from many patients may be misleading. The chosen biomarker, e.g., production of IFN-γ and IL-2 by PBMC upon stimulation with Hsp60, must be assessed before and after stimulation and the results compared within each patient and analyzed with conventional and data mining statistical methods.
[Show abstract][Hide abstract] ABSTRACT: Heat-shock protein (Hsp)10 is the co-chaperone for Hsp60 inside mitochondria, but it also resides outside the organelle. Variations in its levels and intracellular distribution have been documented in pathological conditions, e.g. cancer and chronic obstructive pulmonary disease (COPD). Here, we show that Hsp10 in COPD undergoes changes at the molecular and subcellular levels in bronchial cells from human specimens and derived cell lines, intact or subjected to stress induced by cigarette smoke extract (CSE). Noteworthy findings are: (i) Hsp10 occurred in nuclei of epithelial and lamina propria cells of bronchial mucosa from non-smokers and smokers; (ii) human bronchial epithelial (16HBE) and lung fibroblast (HFL-1) cells, in vitro, showed Hsp10 in the nucleus, before and after CSE exposure; (iii) CSE stimulation did not increase the levels of Hsp10 but did elicit qualitative changes as indicated by molecular weight and isoelectric point shifts; and (iv) Hsp10 nuclear levels increased after CSE stimulation in HFL-1, indicating cytosol to nucleus migration, and although Hsp10 did not bind DNA, it bound a DNA-associated protein.
Open Biology 10/2014; 4(10). DOI:10.1098/rsob.140125 · 5.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: It has been established that Hsp60 can accumulate in the cytosol in various pathological conditions, including cancer and chronic inflammatory diseases. Part or all of the cytosolic Hsp60 could be naïve, namely, bear the mitochondrial import signal (MIS), but neither the structure nor the in solution oligomeric organization of this cytosolic molecule has still been elucidated. Here we present a detailed study of the structure and self-organization of naïve cytosolic Hsp60 in solution. Results were obtained by different biophysical methods (light and X ray scattering, single molecule spectroscopy and hydrodynamics) that all together allowed us to assay a wide range of concentrations of Hsp60. We found that Naïve Hsp60 in aqueous solution is assembled in very stable heptamers and tetradecamers at all concentrations assayed, without any trace of monomer presence.
PLoS ONE 05/2014; 9(5):e97657. DOI:10.1371/journal.pone.0097657 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human mortalin is presented against the background of the Hsp70 family to show its distinctive properties and disease-causing potential. Seventeen genes of the Hsp70 family have recently been characterized applying the chaperonomics protocol to the human genome. One of these genes is HSPA9B, which encodes mortalin, identified in the early 1990s. Mortalin also called mtHsp70, PBP74, GRP75, and HSPA9B, resides inside the mitochondria but can also occur elsewhere. Mortalin is unique within the family because it is more closely related to bacterial than to eukaryotic orthologs, indicating distinctive evolution and functions. Its canonical role pertains to protein folding inside mitochondria in association with Hsp60 (∈Cpn60) and other molecules. However, it is involved also in other processes distinct from protein folding inside and outside mitochondria. It can be predicted that mortalin structure-function defects, inherited or acquired, will have a serious impact on key cellular events, particularly when mitochondria play a role, and in aging. Chaperonopathies due to mortalin malfunction will surely be identified, soon. Existing data indicate that mortalin can be pathogenic, particularly in some types of cancer: mortalin is normal but helps cancer cells to grow, exemplifying the chaperonopathies by mistake, in which a normal chaperone contributes to disease rather than to protection, as expected from a chaperone. Future research offers a multifaceted perspective for mortalin as etiologic factor (chaperonopathies due to chaperone malfunction or mistaken allegiance), disease biomarker, therapeutic target for anti-chaperone compounds (when mortalin is pathogenic), and therapeutic agent in replacement chaperonotherapy (when mortalin is absent or defective).
[Show abstract][Hide abstract] ABSTRACT: Introduction:
Hsp60 (Cpn60) assembles into a tetradecamer that interacts with the co-chaperonin Hsp10 (Cpn10) to assist client polypeptides to fold, but it also has other roles, including participation in pathogenic mechanisms.
Hsp60 chaperonopathies are pathological conditions, inherited or acquired, in which the chaperone plays a determinant etiologic-pathogenic role. These diseases justify selection of Hsp60 as a target for developing agents that interfere with its pathogenic effects. We provide information on how to proceed.
The information available encourages the development of ways to improve Hsp60 activity (positive chaperonotherapy) when deficient or to block it (negative chaperonotherapy) when pathogenic. Many questions are still unanswered and obstacles are obvious. More information is needed to establish when and why autologous Hsp60 becomes a pathogenic autoantigen, or induces cytokine formation and inflammation, or favors carcinogenesis. Clarification of these points will take considerable time. However, analysis of the Hsp60 molecule and a search for active compounds aimed at structural sites that will affect its functioning should continue without interruption. No doubt that some of these compounds will offer therapeutic hopes and will also be instrumental for dissecting structure-function relationships at the biochemical and biological (using animal models and cultured cells) levels.
[Show abstract][Hide abstract] ABSTRACT: The role Hsp60 might play in various inflammatory and autoimmune diseases is under investigation, but little information exists pertaining to Hashimoto's thyroiditis (HT). With the aim to fill this gap, in the present work, we directed our attention to Hsp60 participation in HT pathogenesis. We found Hsp60 levels increased in the blood of HT patients compared to controls. The chaperonin was immunolocalized in thyroid tissue specimens from patients with HT, both in thyrocytes and oncocytes (Hurthle cells) with higher levels compared to controls (goiter). In oncocytes, we found Hsp60 not only in the cytoplasm but also on the plasma membrane, as shown by double immunofluorescence performed on fine needle aspiration cytology. By bioinformatics, we found regions in the Hsp60 molecule with remarkable structural similarity with the thyroglobulin (TG) and thyroid peroxidase (TPO) molecules, which supports the notion that autoantibodies against TG and TPO are likely to recognize Hsp60 on the plasma membrane of oncocytes. This was also supported by data obtained by ELISA, showing that anti-TG and anti-TPO antibodies cross-react with human recombinant Hsp60. Antibody-antigen (Hsp60) reaction on the cell surface could very well mediate thyroid cell damage and destruction, perpetuating inflammation. Experiments with recombinant Hsp60 did not show stimulation of cytokine production by peripheral blood mononuclear cells from HT patients. All together, these results led us to hypothesize that Hsp60 may be an active player in HT pathogenesis via an antibody-mediated immune mechanism.
[Show abstract][Hide abstract] ABSTRACT: Protection of hair cells by HSP70 released by supporting cells is reported by May et al. in this issue of the JCI. Their findings suggest a new way to reduce ototoxicity from therapeutic medications and raise larger questions about the role and integration of heat shock proteins in non–cell-autonomous responses to stress. Increasing evidence suggests an important role for extracellular heat shock proteins in both the nervous system and the immune system. The work also suggests that defective chaperones could cause ear disease and supports the potential use of chaperone therapeutics.
The Journal of clinical investigation 08/2013; 123(8):3206-8. DOI:10.1172/JCI70799 · 13.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this work, we propose that for further studies of the physiopathology and treatment for inflammatory bowel diseases, an integral view of the conditions, including the triad of microbiota-heat shock proteins (HSPs)-probiotics, ought to be considered. Microbiota is the complex microbial flora that resides in the gut, affecting not only gut functions but also the health status of the whole body. Alteration in the microbiota's composition has been implicated in a variety of pathological conditions (e.g., ulcerative colitis, UC), involving both gut and extra-intestinal tissues and organs. Some of these pathologies are also associated with an altered expression of HSPs (chaperones) and this is the reason why they may be considered chaperonopathies. Probiotics, which are live microorganisms able to restore the correct, healthy equilibrium of microbiota composition, can ameliorate symptoms in patients suffering from UC and modulate expression levels of HSPs. However, currently probiotic therapy follows ex-adiuvantibus criteria, i.e., treatments with beneficial effects but whose mechanism of action is unknown, which should be changed so the probiotics needed in each case are predetermined on the basis of the patient's microbiota. Consequently, efforts are necessary to develop diagnostic tools for elucidating levels and distribution of HSPs and the microbiota composition (microbiota fingerprint) of each subject and, thus, guide specific probiotic therapy, tailored to meet the needs of the patient. Microbiota fingerprinting ought to include molecular biology techniques for sequencing highly conserved DNA, e.g., genes encoding 16S RNA, for species identification and, in addition, quantification of each relevant microbe.
Medical Microbiology and Immunology 07/2013; DOI:10.1007/s00430-013-0305-2 · 3.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The classification of chaperonopathies is presented in this chapter. Like many other diseases, chaperonopathies can be genetic or acquired, primary or secondary, structural and/or functional, and qualitative and/or quantitative. In addition, considering pathogenic mechanism, chaperonopathies can be by defect, excess, or mistake. In the latter, a chaperone is normal but favors disease, a situation that occurs, for instance, in various types of cancers. Structural chaperonopathies are characterized by a change in the molecule of a chaperone due to mutation (genetic chaperonopathy) or due to aberrant post-translational modification (acquired chaperonopathy). In both cases, the impact of the structural change depends on which functional domain within the chaperone molecule is modified.
[Show abstract][Hide abstract] ABSTRACT: There is growing evidence that molecular chaperones/heat shock proteins are involved in the pathogenesis of a number of human diseases, known as chaperonopathies. A better molecular understanding of the pathogenetic mechanisms is essential for addressing new strategies in diagnostics, therapeutics and clinical management of chaperonopathies, including those in which Hsp10 is involved. This chaperonin has been studied for a long time as a member of the mitochondrial protein-folding machine. However, although in normal cells Hsp10 is mainly localized in the mitochondrial matrix, it has also been found during and after stress in other subcellular compartments, such as cytosol, vesicles and secretory granules, alone or in combination with other proteins. In these extramitochondrial locales, Hsp10 plays an active role in cell signalling. For example, cancer cells often show altered levels of Hsp10, compared to normal cells. Hsp10 may also be found in the extracellular space and in the bloodstream, with a possible immunomodulatory activity. This minireview focuses on some studies to date on the involvement of Hsp10 in human disease pathogenesis.
Frontiers in bioscience (Elite edition) 01/2013; E5(2):768-778.
[Show abstract][Hide abstract] ABSTRACT: This chapter presents the classification of chaperones, their molecular properties among which that of forming functional complexes involving various molecules, and their distribution inside and outside the cell. The chaperone genes in the human genome are listed and briefly described, focusing on the small heat-shock proteins (sHsp), Hsp60, Hsp70, and Hsp90, and mentioning all others known. The chapter also introduces the concept of chaperoning system, i.e., the physiological system of an organism which is composed of all its chaperones, co-chaperones, and chaperone co-factors.
[Show abstract][Hide abstract] ABSTRACT: Stressors can cause abnormal intracellular accumulation of Hsp60 and its localization in extramitochondrial sites, secretion, and circulation, with immune system activation. Dysfunction of chaperones associated with their quantitative and qualitative decline with aging (chaperonopathies of aging) characterizes senescence and is a potential causal factor in the physiological deterioration that occurs with it. The role of Hsp60 in aging is not easy to elucidate, because aging is accompanied by pathologies (e.g., cardiovascular and neurodegenerative disorders, osteoporosis, diabetes, cancer, etc.) in which Hsp60 has been implicated but, although those disorders are more frequent in the elderly, they are not unique to them. Therefore, it is difficult to determine what is due to aging and what to an associated disease that can occur regardless of age. Does Hsp60 contribute to the pathogenesis? How and when does Hsp60 interact with the immune system and, thus, contributes to the initiation-progression of the generalized chronic inflammation characteristic of aging? These and related issues are discussed here in the light of reports showing the participation of Hsp60 in aging-associated disorders.
Frontiers in Bioscience 01/2013; 18(2):626-37. DOI:10.2741/4126 · 3.52 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this chapter are presented chaperonopathies in which a genetic mechanism is involved but are different from those discussed in chapter 4. Thus, chaperonopathies due to gene dysregulation such as those observed in aged individuals and in some cases with neurodegenerative diseases (e.g., Alzheimer’s, Huntington’s, Parkinson’s, and other conditions), are presented. Likewise, examples of the impact of chaperone-gene polymorphisms on health and disease are given. The quantitative chaperonopathies attributable to gene dysregulation are discussed.
[Show abstract][Hide abstract] ABSTRACT: A mechanism causing a chaperonopathy that is introduced in this chapter consists of the absence of a chaperone from the place where it is needed (i.e., chaperonopathies by misplacement). Also in this chapter are discussed the unfolded-protein response (UPR), chaperone-mediated autophagy (CMA), and illustrative examples of chaperonopathies by mistake, or collaborationism. In these conditions, one or more chaperones, apparently normal in structure, perform functions that favor disease rather than the contrary, hence the name of chaperonopathy by mistake or collaborationism (a molecule that ought to protect the cell and the organism promotes pathogenesis instead). Many examples of chaperonopathies by mistake have been identified involving various chaperones and co-chaperones, including a variety of cancers, and inflammatory and autoimmune conditions. The participation of Hsp60 in these disorders is analyzed in some detail. The potential role of this chaperone as autoantigen and/or as signal molecule is brought up to central stage in certain cancers, myasthenia gravis, Hashimoto’s thyroiditis, chronic obstructive pulmonary disease (COPD), and ulcerative colitis.
[Show abstract][Hide abstract] ABSTRACT: This chapter provides an introduction to the biology and pathology of molecular chaperones, many of which are heat-shock proteins, involved in protein homeostasis and other unrelated functions. When chaperones are defective structurally and/or functionally they may cause disease. These diseases in which chaperones play an etiologic-pathogenic role are the chaperonopathies. The chapter also gives a clinical-pathological overview of chaperonopathies and guidelines for their identification and diagnosis. It briefly describes how to detect and characterize a chaperonopathy in a patient. Chaperones can be useful biomarkers for disease diagnosis and monitoring, including evaluation of prognosis and response to treatment. This and the potential of chaperones for therapy, i.e., chaperonotherapy, are aspects of chaperonology also outlined in the chapter.
[Show abstract][Hide abstract] ABSTRACT: This chapter deals with structural and hereditary chaperonopathies. The chaperonopathies caused by mutations in: sHsp, chaperonin genes (Hsp60 or Cpn60, and CCT subunits), Hsp40/DnaJ, Hsp70, sacsin, and dedicated chaperones (e.g., those involved in microtubule biogenesis, in maintenance of the respiratory chain inside the mitochondria, and others in various cell compartments and tissues), are described and discussed.