Regulatory role of heat-shock proteins in autoimmune and inflammatory diseases

Classically, molecular chaperones play a pivotal role in the maintenance of cellular proteostasis and thus, in the safeguarding of the cell homeostasis while reducing the deleterious effects of extracellular and intracellular stresses. They are also active players in immunologically relevant scenarios such as the activation of innate immunity, antitumour immunity, and autoimmune diseases. It is currently accepted that misdirected immune responses may target self-antigens and generate severe inflammatory responses, a typical signature of autoimmune diseases. In addition to numerous components in immune responses, chaperone proteins are also detected in the extracellular fluids and have been implicated in autoimmune and inflammatory diseases acting as pro- and anti-inflammatory factors. In several inflammatory pathologies, chaperones are greatly induced as a direct consequence of the inflammatory stress and are released from the cell thanks to a poorly understood mechanism. These extracellular chaperones are capable to stimulate anti-inflammatory regulatory T cell responses, thereby inducing the negative feedback control of inflammation. Therefore, it has been proposed that immunization with heat-shock protein peptides could prevent the development of certain diseases. In this article we review the basics of the stress response, summarize current controversies over the role of extracellular chaperones in inflammatory reactions and autoimmunity, and discuss the cytoprotective and immunoregulatory roles of heat-shock proteins, a challenging subject that may open a new avenue for the drug discovery and treatment of diseases related to autoimmune disturbs.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Role of mitochondrial heat-shock proteins and immunophilins in neurodegenerative diseases

Pathophysiologic conditions of neurodegenerative diseases are unquestionably related to protein misfolding. The accumulation of misfolded proteins into relatively ordered structures such as fibrillar intracellular and extracellular amyloids results in tissue lesions that lead to neuronal loss and brain damage. In these pathologies, the occurrence of protein aggregates suggests certain inefficient or insufficient cellular response of those molecular chaperones that should properly assist the folding of the client proteins. In this regard, all the experimental models for neurodegenerative diseases have demonstrated that the overexpression of molecular chaperones provide effective neuroprotection. A subset of these molecular chaperones corresponds to a group of proteins that exhibit peptidylprolyl isomerase enzymatic activity, the immunophilins. Most of the family members of the latter group were first described as responsible of the immunosuppressive response or they were reported as members of the chaperone complex associated with HSP90 in steroid receptor oligomers. In this article we review some aspects of the liaison between molecular chaperones and neurodegenerative diseases, in particular heat-shock proteins and immunophilins with demonstrated influence in the proper function of mitochondria. This article is intended to address a field that represents a yet critical unmet clinical need for the development of neuroprotective molecules focused on potentially novel molecular targets.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Ciucci, Sol Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Mazaira, Gisela Ileana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Galigniana, Mario Daniel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Cyclophilin A is a mitochondrial factor that forms complexes with p23 - correlative evidence for an anti-apoptotic action

Cyclophilin A (CyPA, also known as PPIA) is an abundant and ubiquitously expressed protein belonging to the immunophilin family, which has intrinsic peptidyl-prolyl-(cis/trans)-isomerase enzymatic activity. CyPA mediates immunosuppressive action of the cyclic undecapeptide cyclosporine A and is also involved in multiple cellular processes, such as protein folding, intracellular trafficking, signal transduction and transcriptional regulation. CyPA is abundantly expressed in cancer cells, and, owing to its chaperone nature, its expression is induced upon the onset of stress. In this study, we demonstrated that a significant pool of this immunophilin is primarily an intramitochondrial factor that migrates to the nucleus when cells are stimulated with stressors. CyPA shows anti-apoptotic action per se and the capability of forming ternary complexes with cytochrome c and the small acidic co-chaperone p23, the latter interaction being independent of the usual association of p23 with the heat-shock protein of 90 kDa, Hsp90. These CyPA•p23 complexes enhance the anti-apoptotic response of the cell, suggesting that both proteins form a functional unit, the high level of expression of which plays a significant role in cell survival.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Valeiras, Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gallo, Luciana Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: Lagadari, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

The nuclear receptor field: a historical overview and future challenges

In this article we summarize the birth of the field of nuclear receptors, the discovery ofuntransformed and transformed isoforms of ligand-binding macromolecules, the discovery of thethree-domain structure of the receptors, and the properties of the Hsp90-based heterocomplexresponsible for the overall structure of the oligomeric receptor and many aspects of the biologicaleffects. The discovery and properties of the subfamily of receptors called orphan receptors is alsooutlined. Novel molecular aspects of the mechanism of action of nuclear receptors and challengesto resolve in the near future are discussed.Fil: Mazaira, Gisela Ileana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Zgajnar, Nadia Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Lotufo, Cecilia Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Sivils, Jeffrey C.. University of Texas at El Paso; Estados UnidosFil: Soto, Olga B.. University of Texas at El Paso; Estados UnidosFil: Cox, Marc B.. University of Texas at El Paso; Estados UnidosFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin

The Hsp90-binding immunophilin FKBP52 fosters neurodifferentiation and neuroregeneration in murine models

The term immunophilin involves a family of proteins whose signature domain shows peptidyl-prolyl-(cis/trans)-isomerase (PPIase) enzymatic activity, i.e., the reversible cis/trans interconversion of Xaa-Pro bonds (Erlejman et al., 2013; Annett et al., 2020). The PPIase domain of these proteins usually binds immunosuppressive drugs such as the macrolide FK506 (referred to as the FKBP subfamily) or the cyclic undecapeptide cyclosporine A (called CyP subfamily). The binding of the drug is an event that abrogates the PPIase activity. The smallest members of each subfamily are FKBP12 and CyP17/CyPA are the only proteins responsible for the immunosuppressive action of the cognate drug via calcineurin (or protein-phosphatase 2B) inhibition. This prevents the nuclear translocation of phospho-NFAT, a transcription factor that induces the expression of interleukins and interferon-γ in lymphocytes and are critical components of the cell-mediated immune response. In contrast to those two immunophilins, larger members of the family such as the HSP90-binding immunophilins are not related to immunosuppression and are characterized by the additional presence of degenerate sequences of 34 amino acids repeated in tandem arrays, the TPR domains, through which they interact with the molecular chaperone HSP90. Among them, FKBP51 and FKBP52 are the best studied since they were first described associated to the HSP90-based chaperone heterocomplex of steroid receptors (Storer et al., 2011). Both immunophilins share 75% of amino acid similitude and bind FK506 with equivalent Ki. They play regulatory roles in the steroid-dependent retrotransport of corticosteroid receptors, the translocation of the receptor through the nuclear pore complex, and the hormone-dependent transcriptional regulation (Zgajnar et al., 2019; Mazaira et al., 2020). Usually, both immunophilins show antagonistic action. Thus, FKBP52 favours glucocorticoid binding to the glucocorticoid receptor (GR), the active transport of GR, NF-kB. hTERT and p53 to the nucleus via dynein/dynactin motors, transcriptional activity, telomerase activity, etc., whereas FKBP51 shows inhibitory effects (Lagadari et al., 2016; Daneri-Becerra et al., 2019). In the nervous system, the expression of FKBP51 and FKBP52 is noteworthy in both neurons and glial cells.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Proof that the high molecular weight immunophilin FKBP52 mediates the in vivo neuroregenerative effect of the macrolide FK506

The immunosuppressant drug FK506 (or tacrolimus) is a macrolide that binds selectively to immunophilins belonging to the FK506-binding protein (FKBP) subfamily, which are abundantly expressed proteins in neurons of the peripheral and central nervous systems. Interestingly, it has been reported that FK506 increases neurite outgrowth in cell cultures, implying a potential impact in putative treatments of neurodegenerative disorders and injuries of the nervous system. Nonetheless, the mechanism of action of this compound is poorly understood and remains to be elucidated, with the only certainty that its neurotrophic effect is independent of its primary immunosuppressant activity. In this study it is demonstrated that FK506 shows efficient neurotrophic action in vitro and profound effects on the recovery of locomotor activity, behavioural features, and erectile function of mice that underwent surgical spinal cord injury. The recovery of the locomotor activity was studied in knock-out mice for either immunophilin, FKBP51 or FKBP52. The experimental evidence demonstrates that the neurotrophic actions of FK506 are the consequence of its binding to FKBP52, whereas FK506 interaction with the close-related partner immunophilin FKBP51 antagonises the function of FKBP52. Importantly, our study also demonstrates that other immunophilins do not replace FKBP52. It is concluded that the final biological response is the resulting outcome of the drug binding to both immunophilins, FKBP51 and FKBP52, the latter being the one that commands the dominant neurotrophic action in vivo.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Patiño Gaillez, Michelle Geraldine Sissel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Neuroprotective effect of FK506 against oxidative stress

Immunophilins FKBP51 and FKBP52 bind the macrolide FK506. Previously, we reported that FK506 favours neurodifferentiation and the neuroregeneration. Here, we analyzed whether FK506 also shows neuroprotective action to oxidative stress. A rapid neuritogenesis was observed in undifferentiated N2a cells treated with 1 µM FK506 in the absence of trophic factors, including serum. Then, 250 µm slices from prefrontal cortexes from Balb-C mice (60 d) were prestabilized for 72 h and incubated for 4 h with 200 µM H2O2.Fil: Rosbaco, Maria Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Ramos Hryb, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaXXXIV Anual Meeting SAN 2019Villa Carlos PazArgentinaSociedad Argentina de Investigacion en Neurociencia

Microtubule organization in normal cells and disease: The housekeeping role of heat-shock proteins and immunophilins

Cytoskeleton is the basic scaffold of the cell in which other subcellular components are spatially arranged, such that they are able to communicate efficiently between the internal and external environments of the cell. Cytoskeletal structure is continually remodeled to accommodate normal cell growth and to respond to pathophysiological cues. As a consequence, several cytoskeleton-interacting proteins become involved in a variety of cellular processes such as cell growth and division, cell movement, vesicle transportation, cellular organelle location and function, localization and distribution of membrane receptors, and cell-cell communication. Molecular chaperones and immunophilins are counted among the most important proteins that interact closely with the cytoskeleton network, in particular with microtubules and microtubule-associated factors. In several situations, chaperones and immunophilins work together as a functionally active heterocomplex, although both types of proteins also show independent actions. In circumstances where homeostasis is affected by environmental stresses or due to genetic alterations, chaperone proteins help to stabilize the system. Molecular chaperones facilitate the assembly, disassembly and/or folding/refolding of cytoskeletal proteins, so they prevent aberrant protein aggregation. Nonetheless, the role of chaperones is not limited to solve abnormal situations. They also have an active participation during the normal differentiation process of the cell and are key factors for many structural and functional rearrangements during this course of action. A similar observation is also valid for immunophilins. Although the folding system for microtubules was discovered nearly two decades ago, our understanding of the complex quality control pathway of these filaments is still poorly understood and there are many unanswered questions that remain to be elucidated. Microtubule modifications leading to altered localization nuclear factors may result in loss- or gain-of-function of such factors, which affects the cell cycle and cell development. Therefore, microtubules are attractive therapeutic targets, particularly to prevent pathological situations such as rapidly dividing tumors or to favor the process of cell differentiation in other cases. In this chapter we will address some mechanistic aspects of the key regulatory functions of heat-shock proteins and immunophilins in the microtubule network of neurons and cancer cells.Fil: Quintá, Héctor Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Natalia Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Lagadari, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

Neuroregenerative and neuroprotective actions of immunophilin ligands in murine models

Immunophilins (IMMs) are a family of intracellular proteins that bind immunosuppressive drugs. They are referred to as FK506-binding proteins (FKBPs) when they bind FK506, and cyclophilins (CyPs) when they bind cyclosporine A (CsA). In previous studies performed in cell cultures, we demonstrated that FK506 shows neuroregenerative and neuroprotective actions via FKBPs, the expression balance between FKBP52 and FKBP51 playing a key role during those processes.Fil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zgajnar, Nadia Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Patiño Gaillez, Michelle Geraldine Sissel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaReunión Conjunta de Sociedades de BiocienciasBuenos AiresArgentinaSociedad Argentina de Investigacion ClinicaSociedad Argentina de Investigación en Bioquímica y Biología MolecularSociedad Argentina de InmunologíaSociedad Argentina de AndrologíaSociedad Argentina de BiofísicaSociedad Argentina de BiologíaSociedad Argentina de Farmacología ExperimentalSociedad Argentina de HematologíaSociedad Argentina de Protozoologí

Gene expression regulation by heat-shock proteins: the cardinal roles of HSF1 and Hsp90

The ability to permit gene expression is managed by a set of relatively well known regulatory mechanisms. Nonetheless, such property can also be acquired during the life span as a consequence of environmental stimuli. Interestingly, some acquired information can be passed to the next generation of individuals without modifying gene information, but instead, the manner cells read and process such information. Molecular chaperones are classically related to the proper preservation of protein folding and anti-aggregation properties, but one of them, Hsp90, is a refined sensor of protein function facilitating the biological activity of properly folded client proteins that already have a preserved tertiary structure. Interestingly, Hsp90 can also function as a critical switch able to regulate biological responses due to its association to key client proteins such as histone deacetylases or DNA methylases. Thus, a growing amount of evidence has connected the action of Hsp90 to post-translational modifications of soluble nuclear factors, DNA, and histones, which epigenetically affects gene expression upon the onset of an unfriendly environment. Such response is commanded by the activation of the transcription factor HSF1. Even though a great number of stresses of diverse nature are known to trigger the stress response by activation of HSF1, it is still unanswered whether there are different types of molecular sensors for each type of stimulus. In this article, we will discuss various aspects of the regulatory action of HSF1 and Hsp90 on transcriptional regulation, and how this regulation may impact genetic assimilation mechanisms and the health of individuals.Fil: Mazaira, Gisela Ileana. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Daneri Becerra, Cristina del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Zgajnar, Nadia Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Lotufo, Cecilia Maricel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Galigniana, Mario Daniel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin