Hsp60 and AChR cross-reactivity in myasthenia gravis: An update.

Hsp27 and Hsp60 in human submandibular salivary gland: Quantitative patterns in healthy and cancerous tissues with potential implications for differential diagnosis and carcinogenesis

Tumors of the submandibular salivary gland (SMG) are uncommon but sufficiently frequent for the physician to consider them in routine examinations and for the pathologist to be prepared to differentiate them from other tissue abnormalities. However, scarcity of specimens makes training difficult, a situation compounded by the lack of accepted universal diagnostic guidelines. Furthermore, there is little information on the chaperone system (CS) of the gland, despite the increasing evidence of its participation in carcinogenesis as a biomarker for diagnosis and patient follow up, and in the mechanisms by which the tumor cells thrive. We are investigating this aspect of various tumors, and her…

A human CCT5 gene mutation causing distal neuropathy impairs hexadecamer assembly in an archaeal model

Chaperonins mediate protein folding in a cavity formed by multisubunit rings. The human CCT has eight non-identical subunits and the His147Arg mutation in one subunit, CCT5, causes neuropathy. Knowledge is scarce on the impact of this and other mutations upon the chaperone's structure and functions. To make progress, experimental models must be developed. We used an archaeal mutant homolog and demonstrated that the His147Arg mutant has impaired oligomeric assembly, ATPase activity, and defective protein homeostasis functions. These results establish for the first time that a human chaperonin gene defect can be reproduced and studied at the molecular level with an archaeal homolog. The major…

Myelin pathology: Involvement of molecular chaperones and the promise of chaperonotherapy

The process of axon myelination involves various proteins including molecular chaperones. Myelin alteration is a common feature in neurological diseases due to structural and functional abnormalities of one or more myelin proteins. Genetic proteinopathies may occur either in the presence of a normal chaperoning system, which is unable to assist the defective myelin protein in its folding and migration, or due to mutations in chaperone genes, leading to functional defects in assisting myelin maturation/migration. The latter are a subgroup of genetic chaperonopathies causing demyelination. In this brief review, we describe some paradigmatic examples pertaining to the chaperonins Hsp60 (HSPD1,…

ROLE OF CHAPERONES IN HEALTHY BOWEL AND IBD.

The chaperoning system is the wole complement of chaperones, co-chaperones and chaperone cofactors of the body that preserves cell and tissue homeostasis. Its structural and/or functional defects can cause pathologic conditions, nemed chaperonopathies. Large bowel homeostasis includes a healthy status of the mucosal tissues and the microbiota. An alteration of one of them may determine, in turn, modifications of the other. Molecular chaperones of bacteria and human origin have been implicated in inflammatory bowel disease (IBD). In IBD chaperone levels usually increase and their cellular and subcellular loclization change. This is considered a physiological stress-response of mucosal cells …

Hsp60 expression, new locations, functions and perspectives for cancer diagnosis and therapy.

Hsp60 in eukaryotes is considered typically a mitochondrial chaperone (also called Cpn60) but in the last few years it has become clear that it also occurs in the cytosol, the cell surface, the extracellular space, and in the peripheral blood. Studies with prokaryotic models have shown that Hsp60 plays a role in assisting nascent polypeptides to reach a native conformation, and that it interacts with Hsp10 (which also resides in the mitochondria and is also named Cpn10). In addition to its role in polypeptide folding in association with Hsp10, other functions and interacting molecules have been identified for Hsp60 in the last several years. Some of these newly identified functions are asso…

Hsp60 quantification in human gastric mucosa shows differences between pathologies with various degrees of proliferation and malignancy grade

Background: Stomach diseases are an important sector of gastroenterology, including proliferative benign

Extracellular Vesicle-Mediated Cell–Cell Communication in the Nervous System: Focus on Neurological Diseases

Extracellular vesicles (EVs), including exosomes, are membranous particles released by cells into the extracellular space. They are involved in cell differentiation, tissue homeostasis, and organ remodelling in virtually all tissues, including the central nervous system (CNS). They are secreted by a range of cell types and via blood reaching other cells whose functioning they can modify because they transport and deliver active molecules, such as proteins of various types and functions, lipids, DNA, and miRNAs. Since they are relatively easy to isolate, exosomes can be characterized, and their composition elucidated and manipulated by bioengineering techniques. Consequently, exosomes appear…

Hsp60 Friend and Foe of the Nervous System

Hsp60 belongs to the subgroup of molecular chaperones named chaperonins and, typically, resides and functions in the mitochondria but it is also present in extramitochondrial sites. It chaperones client peptides as they fold to achieve the native conformation and also displays anti-stress roles by helping stress-damaged proteins regain a functional shape. Thus, Hsp60 is central to the integrity and functionality of mitochondria and energy production. All cells in the nervous system depend on Hsp60 so when the chaperonin malfunctions the consequences on nervous tissues are usually devastating, causing diverse diseases. These are the Hsp60 chaperonopathies, which can be genetic or acquired wi…

Brain Tumor-Derived Extracellular Vesicles as Carriers of Disease Markers: Molecular Chaperones and MicroRNAs

Primary and metastatic brain tumors are usually serious conditions with poor prognosis, which reveal the urgent need of developing rapid diagnostic tools and efficacious treatments. To achieve these objectives, progress must be made in the understanding of brain tumor biology, for example, how they resist natural defenses and therapeutic intervention. One resistance mechanism involves extracellular vesicles that are released by tumors to meet target cells nearby or distant via circulation and reprogram them by introducing their cargo. This consists of different molecules among which are microRNAs (miRNAs) and molecular chaperones, the focus of this article. miRNAs modify target cells in the…

Immunohistochemistry of Human Hsp60 in Health and Disease: From Autoimmunity to Cancer

Hsp60 (also called Cpn60) is a chaperonin with essential functions for cell physiology and survival. Additionally, its involvement in the pathogenesis of a variety of diseases (e.g., some autoimmune disorders and cancer) is becoming evident with new research. For example, the distribution and levels of Hsp60 in cells and tissues have been found altered in many pathologic conditions, and the significance of these alterations is being investigated in a number of laboratories. The aim of this ongoing research is to determine the meaning of these Hsp60 alterations with regard to pathogenetic mechanisms, diagnosis, classification of lesions, and assessing prognosis and response to treatment. Hsp…

Molecular chaperones in tumors of salivary glands.

The salivary glands are key components of the mouth and play a central role in its physiology. Their importance may be appreciated considering their number, occurrence in pairs, and distribution in the mouth: two parotids, two submandibular, two sublingual, and many other small ones scattered throughout the mouth. They produce saliva, without which ingestion of non-liquid nutrients and speech would be practically impossible. Nevertheless, the physiology and pathology of salivary glands are poorly understood. For instance, tumors of salivary glands occur, and their incidence is on the rise, but their etiology and pathogenesis are virtually unknown, although some risk factors have been identi…

Hsp60 is actively secreted by human tumor cells

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 S…

Chaperonotherapy for Alzheimer’s Disease: Focusing on HSP60

This review will analyze growing evidence suggesting a convergence between two major areas of research: Alzheimer’s disease (AD) and chaperonopathies. While AD is a widely recognized medical, public health, and social problem, the chaperonopathies have not yet been acknowledged as a related burden of similar magnitude. However, recent evidence collectively indicates that such possibility exists in that AD, or at least some forms of it, may indeed be a chaperonopathy. The importance of considering this possibility cannot be overemphasized since it provides a novel point of view to examine AD and potentially suggests new therapeutic avenues. In this review, we focus on the mitochondrial chape…

Impact of Chaperonopathies in Protein Homeostasis and Beyond

Chaperones have functions other than those classically attributed to them pertaining to protein homeostasis. These “other” non-canonical functions are the focus of chapter 8. The close interaction of the chaperoning and the immune systems and the impact of their malfunctioning on aging and cancer are highlighted. Conversely, the impact of ageing and cancer on the two systems is also underscored. The connections between stress, protein damage (including chaperones), protein misfolding, protein aggregation and precipitation, and tissue degeneration, are analyzed, indicating that all these processes are aggravated by a decline in chaperoning potential with aging (chaperonopathies of the aged) …

Other Types of Chaperonopathies

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 chaperonopat…

Does SARS-CoV-2 Trigger Stress-InducedAutoimmunity by Molecular Mimicry? A Hypothesis.

Viruses can generate molecular mimicry phenomena within their hosts. Why shouldsevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) not be considered one of these?Information in this short review suggests that it might be so and, thus, encourages research aimingat testing this possibility. We propose, as a working hypothesis, that the virus induces antibodiesand that some of them crossreact with host’s antigens, thus eliciting autoimmune phenomena withdevasting consequences in various tissues and organs. If confirmed, by in vitro and in vivo tests,this could drive researchers to find effective treatments against the virus.

Histopathology of Skeletal Muscle in a Distal Motor Neuropathy Associated with a Mutant CCT5 Subunit: Clues for Future Developments to Improve Differential Diagnosis and Personalized Therapy

Genetic chaperonopathies are rare but, because of misdiagnosis, there are probably more cases than those that are recorded in the literature and databases. This occurs because practitioners are generally unaware of the existence and/or the symptoms and signs of chaperonopathies. It is necessary to educate the medical community about these diseases and, with research, to unveil their mechanisms. The structure and functions of various chaperones in vitro have been studied, but information on the impact of mutant chaperones in humans, in vivo, is scarce. Here, we present a succinct review of the most salient abnormalities of skeletal muscle, based on our earlier report of a patient who carried…

Alzheimer's Disease and Molecular Chaperones: Current Knowledge and the Future of Chaperonotherapy

Background: Alzheimer’s disease (AD) is a dementia, a neurodegenerative condition, and a protein-misfolding disease or proteinopathy, characterized by protein deposits, extracellular plaques and intracellular neurofibrillary tangles, which contain the AD’s typical pathological proteins, abnormal [1]-amyloid and hyperphosphorylated tau, respectively, and are located predominantly in the cortex of the frontal, parietal, and temporal brain lobes. What is the role of molecular chaperones in AD? Data indicate that molecular chaperones, also known as Hsp, are involved in AD, probably displaying protective roles and/or acting as pathogenic factors as it occurs in chaperonopathies in which case AD …

Molecular Chaperones and Thyroid Cancer

Thyroid cancers are the most common of the endocrine system malignancies and progress must be made in the areas of differential diagnosis and treatment to improve patient management. Advances in the understanding of carcinogenic mechanisms have occurred in various fronts, including studies of the chaperone system (CS). Components of the CS are found to be quantitatively increased or decreased, and some correlations have been established between the quantitative changes and tumor type, prognosis, and response to treatment. These correlations provide the basis for identifying distinctive patterns useful in differential diagnosis and for planning experiments aiming at elucidating the role of t…

The Odyssey of Hsp60 from Tumor Cells to Other Destinations Includes Plasma Membrane-Associated Stages and Golgi and Exosomal Protein-Trafficking Modalities

BACKGROUND: In a previous work we showed for the first time that human tumor cells secrete Hsp60 via exosomes, which are considered immunologically active microvesicles involved in tumor progression. This finding raised questions concerning the route followed by Hsp60 to reach the exosomes, its location in them, and whether Hsp60 can be secreted also via other mechanisms, e.g., by the Golgi. We addressed these issues in the work presented here. PRINCIPAL FINDINGS: We found that Hsp60 localizes in the tumor cell plasma membrane, is associated with lipid rafts, and ends up in the exosomal membrane. We also found evidence that Hsp60 localizes in the Golgi apparatus and its secretion is prevent…

A mouse model of alcoholic liver disease reveals protection by Lactobacillus fermentum

The knowledge and treatment of alcoholic liver disease is still plagued with gaps mostly due to the inherent limitations of research with patients. We developed an animal model for studying liver histopathology, Hsp-chaperones involvement, and response to treatment. The system was standardized using mice to which ethanol was orally administered alone or in combination with Lactobacillus fermentum for 4, 8 and 12 weeks and applying a battery of techniques (histology, immunohistochemistry, Western blotting, real-time PCR, immunoprecipitation, 3-nitrotyrosine labeling) to assess liver pathology and Hsp60, iNOS gene expression and protein levels, and Hsp60 post-translational modifications. Stea…

Heat shock proteins in embryonic and adult submandibular salivary glands in healthy and tumorigenic tissues

Overview and Book Plan

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 a…

The dissociation of the Hsp60/pro-Caspase-3 complex by bis(pyridyl)oxadiazole copper complex (CubipyOXA) leads to cell death in NCI-H292 cancer cells

Abstract Cell survival and proliferation are central to carcinogenesis, involving various mechanisms among which those that impede apoptosis are important. In this, the role of the molecular chaperone Hsp60 is unclear since it has been reported that it can be both, pro- or anti-apoptotic. A solution to this riddle is crucial to the development of anti-cancer therapies targeting Hsp60. We addressed this question using a tumor cell line, NCI-H292, and [Cu(3,5-bis(2′-pyridyl)-1,2,4-oxadiazole) 2 (H 2 O) 2 ](ClO 4 ) 2 , CubipyOXA , a copper-containing compound with cytotoxic properties. We treated cells with various doses of the compound and measured cell viability; apoptosis indicators; and le…

Is molecular mimicry the culprit in the autoimmune haemolytic anaemia affecting patients with COVID‐19?

The Role of Molecular Chaperones in Virus Infection and Implications for Understanding and Treating COVID-19

The COVID-19 pandemic made imperative the search for means to end it, which requires a knowledge of the mechanisms underpinning the multiplication and spread of its cause, the coronavirus SARS-CoV-2. Many viruses use members of the hosts’ chaperoning system to infect the target cells, replicate, and spread, and here we present illustrative examples. Unfortunately, the role of chaperones in the SARS-CoV-2 cycle is still poorly understood. In this review, we examine the interactions of various coronaviruses during their infectious cycle with chaperones in search of information useful for future research on SARS-CoV-2. We also call attention to the possible role of molecular mimicry in the dev…

Chaperonopathies of senescence and the scrambling of interactions between the chaperoning and the immune systems

Aging entails progressive deterioration of molecules and supramolecular structures, including Hsp chaperones and their complexes, paralleled by functional decline. Recent research has changed our views on Hsp chaperones. They work inside and outside cells in many locations, alone or forming teams, interacting with cells, receptors, and molecules that are not chaperones, in roles that are not typically attributed to chaperones, such as protein folding. Hsp chaperones form a physiological system with a variety of functions and interactions with other systems, for example, the immune system. We propose that chaperone malfunctioning due to structural damage or gene dysregulation during aging ha…

Chaperonopathies and chaperonotherapy. Hsp60 as therapeutic target in cancer: potential benefits and risks.

In this minireview we focus on Hsp60 as a target for anticancer therapy. We discuss the new concepts of chaperonopathies and chaperonotherapy and present information on Hsp60 localization in the cell membrane of human tumor cells. We describe novel mechanisms for Hsp60 reaching the extracellular environment that involve membrane-associated stages, as well as data on anti-Hsp60 antibodies found in human sera, both in normal subjects and patients affected by autoimmune diseases. Finally, we discuss possible therapeutic applications of anti-Hsp60 antibodies in cancer treatment, evaluating also side effects on non-tumor cells. In conclusion, the way for investigating Hsp60-targeted anti-tumor t…

Molecular chaperones expression levels and localization in non-tumoral and tumoral thyroid tissues

Papillary thyroid carcinoma (PTC) is the most frequently occurring subtype of thyroid cancer. Exosomes (EXs) secreted from cells to the extracellular environment play an important role in intercellular communication in normality and pathology. Recent data indicates that tumor cells-derived EXs contribute to cancer progression through the modulation of tumor microenvironment(1). Heat Shock Protein (HSPs) are often overexpressed during carcinogenesis and different studies shown that they can be released by tumors cells and that the mechanism of release is mediated by EXs pathway. In this project we performed an immunomorphological study to investigate Hsp60, 90,70,27 levels expression profile…

Chlamydia trachomatis Infection and Anti-Hsp60 Immunity: The Two Sides of the Coin

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 detai…

Quantitative immunomorphological analysis of heat shock proteins in thyroid follicular adenoma and carcinoma tissues reveals their potential for differential diagnosis and points to a role in carcinogenesis

Hsp27, Hsp60, Hsp70, and Hsp90 are chaperones that play a crucial role in cellular homeostasis and differentiation, but they may be implicated in carcinogenesis. Follicular neoplasms of the thyroid include follicular adenoma and follicular carcinoma. The former is a very frequent benign encapsulated nodule, whereas the other is a nodule that infiltrates the capsule, blood vessels and the adjacent parenchyma, with a tendency to metastasize. The main objective was to assess the potential of the Hsps in differential diagnosis and carcinogenesis. We quantified by immunohistochemistry Hsp27, Hsp60, Hsp70, and Hsp90 on thin sections of human thyroid tissue with follicular adenoma or follicular ca…

The Molecular Anatomy of Human Hsp60 and its Similarity with that of Bacterial Orthologs and Acetylcholine Receptor Reveal a Potential Pathogenetic Role of Anti-Chaperonin Immunity in Myasthenia Gravis.

Heat-shock protein 60 (Hsp60) is ubiquitous and highly conserved being present in eukaryotes and prokaryotes, including pathogens. This chaperonin, although typically a mitochondrial protein, can also be found in other intracellular sites, extracellularly, and in circulation. Thus, it can signal the immune system and participate in the development of inflammation and immune reactions. Both phenomena can be elicited by human and foreign Hsp60 (e.g., bacterial GroEL), when released into the blood by infectious agents. Consequently, all these Hsp60 proteins become part of a complex autoimmune response characterized by multiple cross reactions because of their structural similarities. In this s…

The triad hsp60-mirnas-extracellular vesicles in brain tumors: Assessing its components for understanding tumorigenesis and monitoring patients

Brain tumors have a poor prognosis and progress must be made for developing efficacious treatments, but for this to occur their biology and interaction with the host must be elucidated beyond current knowledge. What has been learned from other tumors may be applied to study brain tumors, for example, the role of Hsp60, miRNAs, and extracellular vesicles (EVs) in the mechanisms of cell proliferation and dissemination, and resistance to immune attack and anticancer drugs. It has been established that Hsp60 increases in cancer cells, in which it occurs not only in the mitochondria but also in the cytosol and plasma-cell membrane and it is released in EVs into the extracellular space and in cir…

The Chaperonopathies: Classification, Mechanisms, Structural Features

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 st…

Hsp60 chaperonopathies and chaperonotherapy: targets and agents

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 pa…

The Chaperone System in Breast Cancer: Roles and Therapeutic Prospects of the Molecular Chaperones Hsp27, Hsp60, Hsp70, and Hsp90

Breast cancer (BC) is a major public health problem, with key pieces of information needed for developing preventive and curative measures still missing. For example, the participation of the chaperone system (CS) in carcinogenesis and anti-cancer responses is poorly understood, although it can be predicted to be a crucial factor in these mechanisms. The chief components of the CS are the molecular chaperones, and here we discuss four of them, Hsp27, Hsp60, Hsp70, and Hsp90, focusing on their pro-carcinogenic roles in BC and potential for developing anti-BC therapies. These chaperones can be targets of negative chaperonotherapy, namely the elimination/blocking/inhibition of the chaperone(s)…

Human Hsp60 with Its Mitochondrial Import Signal Occurs in Solution as Heptamers and Tetradecamers Remarkably Stable over a Wide Range of Concentrations

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 naive, 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 naive 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…

Heat Shock Protein in embryonic and adult submandibular salivary glands in healthy and tumorigenic tissues

Heat Shock Proteins (HSPs) role in development and function of human salivary glands have not yet been measured or mapped in detail, in particular, HSP60 role is unknown. They can be potential biomarkers for glandular diseases and malignancies. We present our initial findings on HSP10, HSP27, HSP60, HSP70 and HSP90 distribution in human submandibular salivary glands (SMG) at various stages of development and tumorigenesis.

Hsp60 response in experimental and human temporal lobe epilepsy due to hyppocampal sclerosis

Hsp60 is widely distributed in the brain, and its alteration has been involved in different neurological disorders. Epilepsy is considered one of the most common neurological disorders and typically involves the hippocampal formation. Compelling evidence describes a role of mitochondria, oxidative stress and both innate and adaptive immunity during epileptogenesis in temporal lobe epilepsy due to hyppocampal sclerosis (TLE-HS). Here, we investigate the Hsp60 involvement in experimental and human epilepsy. Firstly, expression and distribution of Hsp60 in epileptic hippocampi of a rat model of temporal lobe epilepsy (TLE), based on the phenomenon of maximal dentate gyrus activation (MDA), usi…

Hsp60, a Novel Target for Antitumor Therapy: Structure-Function Features and Prospective Drugs Design

Heat shock protein 60 kDa (Hsp60) is a chaperone classically believed to be involved in assisting the correct folding of other mitochondrial proteins. Hsp60 also plays a role in cytoprotection against cell stressors, displaying for example, antiapoptotic potential. Despite the plethora of studies devoted to the mechanism of Hsp60's function, especially in prokaryotes, fundamental issues still remain unexplored, including the definition of its role in cancer. Key questions still unanswered pertain to the differences in structure-function features that might exist between the well-studied prokaryotic GroEL and the largely unexplored eukaryotic Hsp60 proteins. In this article we discuss these …

Chaperones: General Characteristics and Classifications

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.

The neurochaperonopathies: Anomalies of the chaperone system with pathogenic effects in neurodegenerative and neuromuscular disorders

The chaperone (or chaperoning) system (CS) constitutes molecular chaperones, co-chaperones, and chaperone co-factors, interactors and receptors, and its canonical role is protein quality control. A malfunction of the CS may cause diseases, known as the chaperonopathies. These are caused by qualitatively and/or quantitatively abnormal molecular chaperones. Since the CS is ubiquitous, chaperonopathies are systemic, affecting various tissues and organs, playing an etiologic-pathogenic role in diverse conditions. In this review, we focus on chaperonopathies involved in the pathogenic mechanisms of diseases of the central and peripheral nervous systems: the neurochaperonopathies (NCPs). Genetic …

Hsp60 and Hsp10 increase in colon mucosa of Crohn's disease and ulcerative colitis.

The purpose of this work was to determine in colon mucosa of Crohn’s disease (CD) and ulcerative colitis (UC) in relapse: a) the levels of the chaperonins Hsp60 and Hsp10; b) the quantity of inflammatory cells; and c) if the levels of chaperonins parallel those of inflammation cells. Twenty cases of CD and UC and twenty normal controls (NC) were studied using immunohistochemistry, Western blotting and immunofluorescence. Immunohistochemically, Hsp60 and Hsp10 were increased in both inflammatory bowel diseases (IBD) compared to NC. These results were confirmed by Western blotting. Hsp60 and Hsp10 occurred in the cytoplasm of epithelial cells in CD and UC but not in NC. Hsp60 and Hsp10 co-loc…

Quantitative analysis of the impact of a human pathogenic mutation on the CCT5 chaperonin subunit using a proxy archaeal ortholog

The human chaperonin complex is a ~ 1 MDa nanomachine composed of two octameric rings formed from eight similar but non-identical subunits called CCT. Here, we are elucidating the mechanism of a heritable CCT5 subunit mutation that causes profound neuropathy in humans. In previous work, we introduced an equivalent mutation in an archaeal chaperonin that assembles into two octameric rings like in humans but in which all subunits are identical. We reported that the hexadecamer formed by the mutant subunit is unstable with impaired chaperoning functions. This study quantifies the loss of structural stability in the hexadecamer due to the pathogenic mutation, using differential scanning calorim…

Hsp60 Friend and Foe of the Nervous System

Hsp60 belongs to the subgroup of molecular chaperones named chaperonins and, typically, resides and functions in the mitochondria but it is also present in extramitochondrial sites. It chaperones client peptides as they fold to achieve the native conformation and also displays anti-stress roles by helping stress-damaged proteins regain a functional shape. Thus, Hsp60 is central to the integrity and functionality of mitochondria and energy production. All cells in the nervous system depend on Hsp60 so when the chaperonin malfunctions the consequences on nervous tissues are usually devastating, causing diverse diseases. These are the Hsp60 chaperonopathies, which can be genetic or acquired wi…

Muscle Histopathological Abnormalities in a Patient With a CCT5 Mutation Predicted to Affect the Apical Domain of the Chaperonin Subunit.

Recognition of diseases associated with mutations of the chaperone system genes, e.g., chaperonopathies, is on the rise. Hereditary and clinical aspects are established, but the impact of the mutation on the chaperone molecule and the mechanisms underpinning the tissue abnormalities are not. Here, histological features of skeletal muscle from a patient with a severe, early onset, distal motor neuropathy, carrying a mutation on the CCT5 subunit (MUT) were examined in comparison with normal muscle (CTR). The MUT muscle was considerably modified; atrophy of fibers and disruption of the tissue architecture were prominent, with many fibers in apoptosis. CCT5 was diversely present in the sarcolem…

Zebrafish as a Model for the Study of Chaperonopathies

There is considerable information on the clinical manifestations and mode of inheritance for many genetic chaperonopathies but little is known on the molecular mechanisms underlying the cell and tissue abnormalities that characterize them. This scarcity of knowledge is mostly due to the lack of appropriate animal models that mimic closely the human molecular, cellular, and histological characteristics. In this article we introduce zebrafish as a suitable model to study molecular and cellular mechanisms pertaining to human chaperonopathies. Genetic chaperonopathies manifest themselves from very early in life so it is necessary to examine the impact of mutant chaperone genes during developmen…

Structural and Dynamic Disturbances Revealed by Molecular Dynamics Simulations Predict the Impact on Function of CCT5 Chaperonin Mutations Associated with Rare Severe Distal Neuropathies

Mutations in genes encoding molecular chaperones, for instance the genes encoding the subunits of the chaperonin CCT (chaperonin containing TCP-1, also known as TRiC), are associated with rare neurodegenerative disorders. Using a classical molecular dynamics approach, we investigated the occurrence of conformational changes and differences in physicochemical properties of the CCT5 mutations His147Arg and Leu224Val associated with a sensory and a motor distal neuropathy, respectively. The apical domain of both variants was substantially but differently affected by the mutations, although these were in other domains. The distribution of hydrogen bonds and electrostatic potentials on the surfa…

The chaperone system in glioblastoma multiforme and derived cell lines: diagnostic and mechanistic implications.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumor in adults. Novel treatments are needed to counteract the molecular mechanisms of GBM growth and drug resistance. The chaperone system (CS) members are typically cytoprotective but some, termed Hsp, can become pathogenic and participate in carcinogenesis, along with the vascular endothelial growth factor (VEGF), and we investigated them in GBM biopsies and derived cell lines. The objectives were to identify diagnostic-prognostic biomarkers and gather information for developing chaperonotherapy. METHODS: Cell lines from GBMs were established, characterized (morphology, growth characteristics, and sp…

Heat shock protein 60 levels in tissue and circulating exosomes in human large bowel cancer before and after ablative surgery

BACKGROUND: Heat shock protein 60 (Hsp60) is a chaperonin involved in tumorigenesis, but its participation in tumor development and progression is not well understood and its value as a tumor biomarker has not been fully elucidated. In the current study, the authors presented evidence supporting the theory that Hsp60 has potential as a biomarker as well as a therapeutic target in patients with large bowel cancer. METHODS: The authors studied a population of 97 subjects, including patients and controls. Immunomorphology, Western blot analysis, and quantitative real-time polymerase chain reaction were performed on tissue specimens. Exosomes were isolated from blood and characterized by electr…

Molecular chaperones and mirnas in epilepsy: Pathogenic implications and therapeutic prospects

Epilepsy is a pathologic condition with high prevalence and devastating consequences for the patient and its entourage. Means for accurate diagnosis of type, patient monitoring for predicting seizures and follow up, and efficacious treatment are desperately needed. To improve this adverse outcome, miRNAs and the chaperone system (CS) are promising targets to understand pathogenic mechanisms and for developing theranostics applications. miRNAs implicated in conditions known or suspected to favor seizures such as neuroinflammation, to promote epileptic tolerance and neuronal survival, to regulate seizures, and others showing variations in expression levels related to seizures are promising ca…

HSP60 activity on human bronchial epithelial cells

HSP60 has been implicated in chronic inflammatory disease pathogenesis, including chronic obstructive pulmonary disease (COPD), but the mechanisms by which this chaperonin would act are poorly understood. A number of studies suggest a role for extracellular HSP60, since it can be secreted from cells and bind Toll-like receptors; however, the effects of this stimulation have never been extensively studied. We investigated the effects (pro- or anti-inflammatory) of HSP60 in human bronchial epithelial cells (16-HBE) alone and in comparison with oxidative, inflammatory, or bacterial challenges. 16-HBE cells were cultured for 1–4 h in the absence or presence of HSP60, H2O2, lipopolysaccharide (…

Exosomal HSP60 levels and related miRNAs in brain tumors

In cancer, Extracellular Vesicles (EVs), such as exosomes, contribute to tumor progression by regulating local and systemic parameters. Since exosomes are released into body fluids, they may be used in nanomedicine as a valuable source of diagnostic biomarkers. The prognosis of brain tumors is poor even after surgical resection followed by post-operatory chemo- and radio-therapies and it is cogent to find innovative treatments. The discovery that molecular chaperones can be determinant factors in tumorigenesis and the increasing understanding of exosomes, particularly in what refers to their release by tumor cells and contents, including chaperones and miRNA, provide elements to develop nov…

Missense Mutations of Human Hsp60: A Computational Analysis to Unveil Their Pathological Significance

Two chaperonopathies have been linked to mutations in the human hsp60 (hHsp60; HSPD1) gene, but other existing variants might cause diseases, even if there is no comprehensive information about this possibility. To fill this vacuum, which might be at the basis of misdiagnoses or simply ignorance of chaperonopathies in patients who would benefit by proper identification of their ailments, we searched the sequenced human genomes available in public databases to determine the range of missense mutations in the single hsp60 gene. A total of 224 missense mutations were identified, including those already characterized. Detailed examination of these mutations was carried out to assess their possi…

The histone deacetylase inhibitor SAHA induces HSP60 nitration and its extracellular release by exosomal vesicles in human lung-derived carcinoma cells

// Claudia Campanella 1, 2, * , Antonella D'Anneo 3, * , Antonella Marino Gammazza 1, 2, * , Celeste Caruso Bavisotto 1, 2 , Rosario Barone 1, 2 , Sonia Emanuele 4 , Filippa Lo Cascio 1 , Emanuele Mocciaro 1 , Stefano Fais 5 , Everly Conway De Macario 6 , Alberto J.L. Macario 2, 6 , Francesco Cappello 1, 2 , Marianna Lauricella 4 1 Department of Experimental Biomedicine and Clinical Neurosciences, Section of Human Anatomy “Emerico Luna”, University of Palermo, Palermo, Italy 2 Euro-Mediterranean Institute of Science and Technology, Palermo, Italy 3 Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, Laboratory of Biochemistry, University of Palermo, Palermo, Ita…

Doxorubicin anti-tumor mechanisms include Hsp60 post-translational modifications leading to the Hsp60/p53 complex dissociation and instauration of replicative senescence.

Hsp60 is a pro-carcinogenic chaperonin in certain tumor types by interfering with apoptosis and with tumor cell death. In these tumors, it is not known whether or not doxorubicin anti-tumor effects include a blockage of the pro-carcinogenic action of this protein. We used the human lung mucoepidermoid cell line NCI-H292 and different doses of doxorubicin to measure cell viability, cell cycle progression, cell senescence indicators, Hsp60 levels and its post-translational modifications as well as the release of the chaperonin into the extracellular environment. Cell viability was reduced in relation to doxorubicin dose and this was paralleled by the appearance of cell senescence markers. Con…

The molecular anatomy of human Hsp60 and its effects on Amyloid-β peptide

Heat Shock Protein 60 (HSP60) is ubiquitous and highly conserved, being present in eukaryotes and prokaryotes, including pathogens. This chaperonin is typically considered a mitochondrial protein but it is also found in other intracellular sites, extracellularly and in circulation. HSP60 is an indispensable component of the Chaperoning System and plays a key role in protein quality control, preventing off-pathway folding events and refolding misfolded proteins. This makes HSP60 a putative therapeutic agent for neurodegenerative diseases associated with aggregation of misfolded proteins, for example, Alzheimer’s Disease. We produced and purified recombinant human HSP60 and investigated the e…

Heat-shock protein 60 kDa and atherogenic dyslipidemia in patients with untreated mild periodontitis: a pilot study

Identification of predictors of cardiovascular risk can help in the prevention of pathologic episodes and the management of patients at all stages of illness. Here, we investigated the relationships between serum levels of Hsp60 and dyslipidemia in patients with periodontitis by performing a cross-sectional study of 22 patients with mild periodontitis without any prior treatment for it (i.e., drug naive) and 22 healthy controls, matched for age and body mass index (BMI). All subjects were evaluated for periodontal status, gingival inflammation, and oral hygiene. Levels of circulating Hsp60, C-reactive protein (CRP), and plasma lipids were measured, and small, dense low-density lipoproteins …

SARS-CoV-2 in patients with cancer: possible role of mimicry of human molecules by viral proteins and the resulting anti-cancer immunity

AbstractA few reports suggest that molecular mimicry can have a role in determining the more severe and deadly forms of COVID-19, inducing endothelial damage, disseminated intravascular coagulation, and multiorgan failure. Heat shock proteins/molecular chaperones can be involved in these molecular mimicry phenomena. However, tumor cells can display on their surface heat shock proteins/molecular chaperones that are mimicked by SARS-CoV-2 molecules (including the Spike protein), similarly to what happens in other bacterial or viral infections. Since molecular mimicry between SARS-CoV-2 and tumoral proteins can elicit an immune reaction in which antibodies or cytotoxic cells produced against t…

Unexpected tumor reduction in metastatic colorectal cancer patients during SARS-Cov-2 infection: effect of ACE-2 expression on tumor cells or molecular mimicry phenomena? Two not mutually exclusive hypotheses

The chaperone system in cancer therapies: Hsp90

AbstractThe chaperone system (CS) of an organism is composed of molecular chaperones, chaperone co-factors, co-chaperones, and chaperone receptors and interactors. It is present throughout the body but with distinctive features for each cell and tissue type. Previous studies pertaining to the CS of the salivary glands have determined the quantitative and distribution patterns for several members, the chaperones, in normal and diseased glands, focusing on tumors. Chaperones are cytoprotective, but can also be etiopathogenic agents causing diseases, the chaperonopathies. Some chaperones such as Hsp90 potentiate tumor growth, proliferation, and metastasization. Quantitative data available on t…

Hsp60 and Hsp10 in Ageing

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 …

CD1A-positive cells and HSP60 (HSPD1) levels in keratoacanthoma and squamous cell carcinoma.

CD1a is involved in presentation to the immune system of lipid antigen derived from tumor cells with subsequent T cell activation. Hsp60 is a molecular chaperone implicated in carcinogenesis by, for instance, modulating the immune reaction against the tumor. We have previously postulated a synergism between CD1a and Hsp60 as a key factor in the activation of an effective antitumor immune response in squamous epithelia. Keratoacantomas (KAs) are benign tumors that however can transform into squamous cell carcinomas (SCCs), but the reasons for this malignization are unknown. In a previous study, we found that CD1a-positive cells are significantly more numerous in KA than in SCC. In this study…

Corrigendum to “Hsp60 and AChR cross-reactivity in myasthenia gravis: An update.” [J. Neurol. Sci. 292 (2010) 117–118]

Corrigendum to “Hsp60 and AChR cross-reactivity in myasthenia gravis: An update.” [J. Neurol. Sci. 292 (2010) 117–118] Francesco Cappello ⁎, Antonella Marino Gammazza, Leila Zummo, Everly Conway de Macario, Alberto J.L. Macario a Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Via del Vespro 129, 90127, Palermo, Italy b University of Maryland, IMET, 701 East Pratt Street, 21202, Baltimore, MD, USA

ALCOHOLIC LIVER DISEASE: A MOUSE MODEL REVEALS PROTECTION BY LACTOBACILLUS FERMENTUM

Objectives Alcoholism is one of the most devastating diseases with high incidence, but knowledge of its pathology and treatment is still plagued with gaps mostly because of the inherent limitations of research with patients. We developed an animal model for studying liver histopathology, Hsp (heat-shock protein)-chaperones involvement, and response to treatment. Methods The system was standardized using mice to which ethanol was orally administered alone or in combination with Lactobacillus fermentum following a precise schedule over time and applying, at predetermined intervals, a battery of techniques (histology, immunohistochemistry, western blotting, real-time PCR, immunoprecipitation, …

Human molecular chaperones share with SARS-CoV-2 antigenic epitopes potentially capable of eliciting autoimmunity against endothelial cells: possible role of molecular mimicry in COVID-19

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2), the cause of COVID-19 disease, has the potential to elicit autoimmunity because mimicry of human molecular chaperones by viral proteins. We compared viral proteins with human molecular chaperones, many of which are heat shock proteins, to determine if they share amino acid-sequence segments with immunogenic-antigenic potential, which can elicit cross-reactive antibodies and effector immune cells with the capacity to damage-destroy human cells by a mechanism of autoimmunity. We identified the chaperones that can putatively participate in molecular mimicry phenomena after SARS-CoV-2 infection, focusing on those for which endotheli…

Chaperonology: The Third Eye on Brain Gliomas

The European Organization for Research and Treatment of Cancer/National Cancer Institute of Canada Phase III trial has validated as a current regimen for high-grade gliomas (HGG) a maximal safe surgical resection followed by radiotherapy with concurrent temozolamide. However, it is essential to balance maximal tumor resection with preservation of the patient&rsquo

Changes in immunohistochemical levels and subcellular localization after therapy and correlation and colocalization with CD68 suggest a pathogenetic role of Hsp60 in ulcerative colitis.

In an earlier work, the role of heat shock protein (Hsp60) in the pathogenesis of ulcerative colitis (UC) was suggested by its significant increase in the pathological mucosa parallel with an increase in inflammatory cells. More data in this direction are reported in this work. We analyzed by immunohistochemistry biopsies of colon tissue from 2 groups of patients with UC and treated with either 5-aminosalicylic acid (5-ASA) alone or in combination with a probiotic. We looked for inflammatory markers and Hsp60. Both the treatments were effective in reducing symptoms but the group treated with both 5-ASA and probiotics showed better clinical results. Amelioration of symptoms was associated wi…

A Novel CCT5 Missense Variant Associated with Early Onset Motor Neuropathy

Diseases associated with acquired or genetic defects in members of the chaperoning system (CS) are increasingly found and have been collectively termed chaperonopathies. Illustrative instances of genetic chaperonopathies involve the genes for chaperonins of Groups I (e.g., Heat shock protein 60, Hsp60) and II (e.g., Chaperonin Containing T-Complex polypeptide 1, CCT). Examples of the former are hypomyelinating leukodystrophy 4 (HLD4 or MitCHAP60) and hereditary spastic paraplegia (SPG13). A distal sensory mutilating neuropathy has been linked to a mutation [p.(His147Arg)] in subunit 5 of the CCT5 gene. Here, we describe a new possibly pathogenic variant [p.(Leu224Val)] of the same subunit b…

Chaperonin of Group I: Oligomeric spectrum and biochemical and biological implications

Chaperonins play various physiological roles and can also be pathogenic. Elucidation of their structure, e.g., oligomeric status and post-translational modifications (PTM), is necessary to understand their functions and mechanisms of action in health and disease. Group I chaperonins form tetradecamers with two stacked heptameric rings. The tetradecamer is considered the typical functional complex for folding of client polypeptides. However, other forms such as the monomer and oligomers with smaller number of subunits than the classical tetradecamer, also occur in cells. The properties and functions of the monomer and oligomers, and their roles in chaperonin-associated diseases are still inc…

Molecular mimicry may explain multi-organ damage in COVID-19

International audience

The Challenging Riddle about the Janus-Type Role of Hsp60 and Related Extracellular Vesicles and miRNAs in Carcinogenesis and the Promises of Its Solution

Hsp60 is one of the most ancient and evolutionarily conserved members of the chaperoning system. It typically resides within mitochondria, in which it contributes to maintaining the organelle’s proteome integrity and homeostasis. In the last few years, it has been shown that Hsp60 also occurs in other locations, intracellularly and extracellularly, including cytosol, plasma-cell membrane, and extracellular vesicles (EVs). Consequently, non-canonical functions and interacting partners of Hsp60 have been identified and it has been realized that it is a hub molecule in diverse networks and pathways and that it is implicated, directly or indirectly, in the development of various pathological co…

The Chaperone System in Salivary Glands: Hsp90 Prospects for Differential Diagnosis and Treatment of Malignant Tumors

Salivary gland tumors represent a serious medical problem and new tools for differential diagnosis and patient monitoring are needed. Here, we present data and discuss the potential of molecular chaperones as biomarkers and therapeutic targets, focusing on Hsp10 and Hsp90. The salivary glands are key physiological elements but, unfortunately, the information and the means available for the management of their pathologies, including cancer, are scarce. Progress in the study of carcinogenesis has occurred on various fronts lately, one of which has been the identification of the chaperone system (CS) as a physiological system with presence in all cells and tissues (including the salivary gland…

Gut microbiota imbalance and chaperoning system malfunction are central to ulcerative colitis pathogenesis and can be counteracted with specifically designed probiotics: a working hypothesis

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…

Circulating Molecular Chaperones in Subjects with Amnestic Mild Cognitive Impairment and Alzheimer’s Disease: Data from the Zabùt Aging Project

Molecular chaperones play essential roles in many processes such as cell differentiation, tissue homeostasis, and organ remodeling. Recent data indicate that chaperones can act as cytoprotectants for brain cells during the progression of neurodegenerative diseases, including Alzheimer’s disease (AD). However, very few data on the levels of chaperones in dementia, including its prodromal phases, have been reported. In this study, we used biological samples and epidemiological data collected during the Zabùt Aging Project (a prospective, community-based, cohort study of normal/pathological aging conducted in Sicily, Italy, with a follow-up of ten years) to determine if there is an association…

HSP60: A Story as Long as Life on the Earth

In this Chapter, we briefly recount a few salient aspects of our personal experience and ideas about one of the most important anti-stress proteins in all cells, i.e., HSP60 (HSPD1 in humans). We outline the progression of HSP60 from gene to protein and its voyages inside and outside the cell, mentioning its various roles in health and disease. We correlate scientific data obtained by different experimental approaches to personal visions about the existence of life on Earth, its perpetuation, and the future of the human-species evolution. We believe that Science should not only be the application of technologies to find an answer to an unsolved question but also a source of philosophical co…

Immunomorphological Patterns of Chaperone System Components in Rare Thyroid Tumors with Promise as Biomarkers for Differential Diagnosis and Providing Clues on Molecular Mechanisms of Carcinogenesis

Hurthle cell (HC), anaplastic (AC), and medullary (MC) carcinomas are low frequency thyroid tumors that pose several challenges for physicians and pathologists due to the scarcity of cases, information, and histopathological images, especially in the many areas around the world in which sophisticated molecular and genetic diagnostic facilities are unavailable. It is, therefore, cogent to provide tools for microscopists to achieve accurate diagnosis, such as histopathological images with reliable biomarkers, which can help them to reach a differential diagnosis. We are investigating whether components of the chaperone system (CS), such as the molecular chaperones, can be considered dependabl…

Immunomorphological Pattern of Molecular Chaperones in Normal and Pathological Thyroid Tissues and Circulating Exosomes: Potential Use in Clinics

The thyroid is a major component of the endocrine system and its pathology can cause serious diseases, e.g., papillary carcinoma (PC). However, the carcinogenic mechanisms are poorly understood and clinical useful biomarkers are scarce. Therefore, we determined if there are quantitative patterns of molecular chaperones in the tumor tissue and circulating exosomes that may be useful in diagnosis and provide clues on their participation in carcinogenesis. Hsp27, Hsp60, Hsp70, and Hsp90 were quantified by immunohistochemistry in PC, benign goiter (BG), and normal peritumoral tissue (PT). The same chaperones were assessed in plasma exosomes from PC and BG patients before and after ablative surg…

Hsp60 as a Novel Target in IBD Management: A Prospect

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 …

Exosomal HSP60: a potentially useful biomarker for diagnosis, assessing prognosis, and monitoring response to treatment.

Introduction: Cell-to-cell communication is imperative for life and it is mediated by sending and receiving information via the secretion and subsequent receptor-mediated detection of biological molecules. Exosomes (EXs) secreted from cells to the extracellular environment play an important role in intercellular communication in normal and pathological conditions. Areas covered: New evidence indicates that tumor cells-derived EXs contribute to cancer progression through the modulation of tumor microenvironment. The exosomal heat shock protein 60 (HSP60) is very likely a key player in intercellular cross-talk, particularly during the progress of diseases, such as cancer. Many studies have fo…

Hsp10 nuclear localization and changes in lung cells response to cigarette smoke suggest novel roles for this chaperonin

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) a…

HSP60 is a ubiquitous player in the physiological and pathogenic interactions between the chaperoning and the immune systems

HSP60 participates in many interactions between the system integrated by all chaperones and closely associated molecules (chaperoning system or CS) and the immune system (IS). These interactions occur constantly to maintain normal cell physiology but, occasionally, they are perturbed and become mediators of pathologic events that may lead to disease. This switch to pathology may be initiated by various factors, genetic or acquired, which cause qualitative and/or quantitative modifications of HSP60, or immune crossreactivity between the human and microbial chaperonin orthologs, or a break in the balance between the pro- and anti-inflammatory actions of the chaperonin. Thus, autoimmune and ch…

Molecular Pathways Implicated in Radioresistance of Glioblastoma Multiforme: What Is the Role of Extracellular Vesicles?

Glioblastoma multiforme (GBM) is a primary brain tumor that is very aggressive, resistant to treatment, and characterized by a high degree of anaplasia and proliferation. Routine treatment includes ablative surgery, chemotherapy, and radiotherapy. However, GMB rapidly relapses and develops radioresistance. Here, we briefly review the mechanisms underpinning radioresistance and discuss research to stop it and install anti-tumor defenses. Factors that participate in radioresistance are varied and include stem cells, tumor heterogeneity, tumor microenvironment, hypoxia, metabolic reprogramming, the chaperone system, non-coding RNAs, DNA repair, and extracellular vesicles (EVs). We direct our a…

Hsp60 Post-translational Modifications: Functional and Pathological Consequences.

Hsp60 is a chaperone belonging to the Chaperonins of Group I and typically functions inside mitochondria in which, together with the co-chaperonin Hsp10, maintains protein homeostasis. In addition to this canonical role, Hsp60 plays many others beyond the mitochondria, for instance in the cytosol, plasma-cell membrane, extracellular space, and body fluids. These non-canonical functions include participation in inflammation, autoimmunity, carcinogenesis, cell replication, and other cellular events in health and disease. Thus, Hsp60 is a multifaceted molecule with a wide range of cellular and tissue locations and functions, which is noteworthy because there is only one hsp60 gene. The questio…

Hsp60 response in experimental and human temporal lobe epilepsy

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 …

Lipid chaperones and associated diseases: a group of chaperonopathies defining a new nosological entity with implications for medical research and practice.

AbstractFatty acid–binding proteins (FABPs) are lipid chaperones assisting in the trafficking of long-chain fatty acids with functions in various cell compartments, including oxidation, signaling, gene-transcription regulation, and storage. The various known FABP isoforms display distinctive tissue distribution, but some are active in more than one tissue. Quantitative and/or qualitative changes of FABPs are associated with pathological conditions. Increased circulating levels of FABPs are biomarkers of disorders such as obesity, insulin resistance, cardiovascular disease, and cancer. Deregulated expression and malfunction of FABPs can result from genetic alterations or posttranslational mo…

Exosomal Chaperones and miRNAs in Gliomagenesis: State-of-Art and Theranostics Perspectives

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…

Functions and Therapeutic Potential of Extracellular Hsp60, Hsp70, and Hsp90 in Neuroinflammatory Disorders

Neuroinflammation is implicated in central nervous system (CNS) diseases, but the molecular mechanisms involved are poorly understood. Progress may be accelerated by developing a comprehensive view of the pathogenesis of CNS disorders, including the immune and the chaperone systems (IS and CS). The latter consists of the molecular chaperones; cochaperones; and chaperone cofactors, interactors, and receptors of an organism and its main collaborators in maintaining protein homeostasis (canonical function) are the ubiquitin–proteasome system and chaperone-mediated autophagy. The CS has also noncanonical functions, for instance, modulation of the IS with induction of proinflammatory cytokines. …

Quantitative patterns of Hsps in tubular adenoma compared with normal and tumor tissues reveal the value of Hsp10 and Hsp60 in early diagnosis of large bowel cancer

Large bowel carcinogenesis involves accumulation of genetic alterations leading to transformation of normal mucosa into dysplasia and, lastly, adenocarcinoma. It is pertinent to elucidate the molecular changes occurring in the pre-neoplastic lesions to facilitate early diagnosis and treatment. Heat shock proteins (Hsps), many of which are molecular chaperones, are implicated in carcinogenesis, and their variations with tumor progression encourage their study as biomarkers. There are many reports on Hsps and cancer but none to our knowledge on their systematic quantification in pre-neoplastic lesions of the large bowel. We performed immunohistochemical determinations of Hsp10, Hsp60, Hsp70, …

Heat Shock Protein-60 and Risk for Cardiovascular Disease

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality worldwide. There is growing evidence that molecularchaperones, many of which are heat shock proteins HSPs, are involved in CVD pathogenesis. In this review we focus on HSP60,the human mitochondrial chaperone that also displays extramitochondrial and extracellular functions. HSP60 is typically cytoprotectivebut a number of stress conditions determine its conversion to a potentially toxic molecule for cells and tissues. We present illustrative examplesof specific subtypes of CVD where HSP60 is implicated in the initiation and/or progression of disease. The data not only indicatea pathogenic role for HSP60 but also its …

Exosomal Hsp60 levels and related miRNA in brain tumor cells

One of the many pathologic conditions still without a satisfactory solution is that of brain tumors. The prognosis is poor even after surgical resection followed by post-operatory chemo- and radio-therapie (1). It is, therefore, cogent to find innovative treatment tools. Three recent developments may provide elements to discover novel treatment strategies and means. These developments are: the discovery that molecular chaperones can be determinant factors in the process of tumorigenesis (2); the elucidation of the role of miRNAs in gene regulation and determination of protein functions, including molecular chaperones; in the various cell compartments (3);the increasing understanding and cha…

Human Hsp10 and Early Pregnancy Factor (EPF) and their relationship and involvement in cancer and immunity: current knowledge and perspectives.

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 t…

Chaperonin Hsp60 and Cancer Therapies

The heat shock protein 60 (Hsp60) is a chaperonin belonging to the chaperoning (chaperone) system that typically contributes to protein homeostasis inside mitochondria, but also plays various non-canonical roles unrelated to protein quality control beyond the organelle. Chaperonopathies are disorders in which chaperones play an etiologic-pathogenic role and contribute to the onset/progression of disease. Hsp60 chaperonopathies by mistake are diseases in which the chaperonin is apparently normal (as far as it can be determined with current methodologies) but it actively contributes to pathology, for example in certain types of cancer, and autoimmune and chronic inflammatory disorders. In cer…

Other Genetic Chaperonopathies

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.

Skeletal muscle Heat shock protein 60 increases after endurance training and induces peroxisome proliferator-activated receptor gamma coactivator 1 α1 expression

AbstractHeat shock protein 60 (Hsp60) is a chaperone localizing in skeletal muscle mitochondria, whose role is poorly understood. In the present study, the levels of Hsp60 in fibres of the entire posterior group of hindlimb muscles (gastrocnemius, soleus and plantaris) were evaluated in mice after completing a 6-week endurance training program. The correlation between Hsp60 levels and the expression of four isoforms of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) were investigated only in soleus. Short-term overexpression of hsp60, achieved by in vitro plasmid transfection, was then performed to determine whether this chaperone could have a role in the activa…

Data mining-based statistical analysis of biological data uncovers hidden significance: clustering Hashimoto’s thyroiditis patients based on the response of their PBMC with IL-2 and IFN-γ secretion to stimulation with Hsp60

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 ana…

Convergent sets of data from in vivo and in vitro methods point to an active role of Hsp60 in chronic obstructive pulmonary disease pathogenesis.

BackgroundIt is increasingly clear that some heat shock proteins (Hsps) play a role in inflammation. Here, we report results showing participation of Hsp60 in the pathogenesis of chronic obstructive pulmonary diseases (COPD), as indicated by data from both in vivo and in vitro analyses.Methods and resultsBronchial biopsies from patients with stable COPD, smoker controls with normal lung function, and non-smoker controls were studied. We quantified by immunohistochemistry levels of Hsp10, Hsp27, Hsp40, Hsp60, Hsp70, Hsp90, and HSF-1, along with levels of inflammatory markers. Hsp10, Hsp40, and Hsp60 were increased during progression of disease. We found also a positive correlation between th…

Hsp60 molecular anatomy and role in colorectal cancer diagnosis and treatment

Quantitative changes in Hsp60 during the development of some tumors suggest that this chaperonin plays a role in carcinogenesis. A description of the specific role(s) of Hsp60 in tumor-cell growth and proliferation is still incomplete, but it is already evident that monitoring its levels and distribution in tissues and fluids has potential for diagnosis and staging, and for assessing prognosis and response to treatment. Although Hsp60 is considered an intramitochondrial protein, it has been demonstrated in the cytosol, cell membrane, vesicles, cell surface, extracellular space, and blood. The knowledge that Hsp60 occurs at all these locations opens new avenues for basic and applied research…

Structural and Hereditary Chaperonopathies: Mutation

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.

THE CHAPERONE SYSTEM IN SALIVARY GLAND DEVELOPMENT

The chaperone system (CS) canonical function is to maintain protein homeostasis. Proper folding of nascent peptides is crucial in developing tissue. The chief components of the CS are 95th National Congress of the Italian Society for Experimental Biology | Trieste, Italy, 12-15 April 2023Non-commercial use only the molecular chaperones, which play key roles in development as indicated by their presence in embryonic tissue as early as at two-cell stage. However, scarce information on the CS in developing tissues is available, especially at advanced stages of embryogenesis and its role is not fully understood. In our previous study, we reported the presence of molecular chaperones in the duct…

Elevated blood Hsp60, its structural similarities and cross-reactivity with thyroid molecules, and its presence on the plasma membrane of oncocytes point to the chaperonin as an immunopathogenic factor in Hashimoto's thyroiditis.

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 …