RESUMO
BACKGROUND: Recent lines of research have boosted awareness of the immunological facets of schizophrenia. However, associations with protein tyrosine phosphatase regulators have never been reported. The aim of our study was to investigate the expression and promoter status methylation of phosphatase SHP-1, a key negative regulator of the inflammatory process, in Peripheral blood mononuclear cells (PBMCs) of Schizophrenic patients. METHODS: We enrolled fifty-four (28 men and 26 women) unmedicated first episode subjects (SC) who met DSM-IV and thirty-eight (22 men and 16 women) healthy controls (HC). The SC psychopathological status was assessed using the Positive and Negative Syndrome Scale. We evaluated SHP-1 expression by Quantitative Real-time PCR (qPCR) and Western blotting (WB) methods and promoter status methylation through PCR bisulfate. IKK/NFkB signaling was detected by WB, and medium and plasma levels of pro-inflammatory cytokines (IL-1ß, IL-2, and TNF-α) by the ELISA method. SHP-1 was silenced by treating cells with specific siRNA. RESULTS: We found a significantly lower level of SHP-1 gene expression in PBMCs from SC vs. HC, consistently with which the promoter region analyzed presented significant hypermethylation. Silencing of SHP-1 expression induced higher activation of IKK/NF-kB signaling and pro-inflammatory cytokine production in ex vivo PBMCs from both SC and HC. Linear regression among patients generated a model in which SHP-1 expression explained 30% of the clinical negative symptom variance (adjusted R(2)=0.30, ANOVA p<0.001). CONCLUSIONS: Our findings are the first to suggest that impairment of SHP-1 expression is involved in the physiopathology of schizophrenia, opening fruitful new avenues for ameliorating treatment at least of negative symptoms.
Assuntos
Citocinas/biossíntese , Proteína Tirosina Fosfatase não Receptora Tipo 6/fisiologia , Esquizofrenia/enzimologia , Adulto , Proteína C-Reativa/análise , Citocinas/genética , Metilação de DNA , Feminino , Humanos , Quinase I-kappa B/metabolismo , Leucócitos Mononucleares/enzimologia , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , Proteína Tirosina Fosfatase não Receptora Tipo 6/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 6/biossíntese , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Interferente Pequeno/farmacologia , Esquizofrenia/genética , Esquizofrenia/imunologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Índice de Gravidade de DoençaRESUMO
Heart failure (HF) is a common clinical syndrome with frequent exacerbations requiring hospitalization. Among the various mechanisms that underlie the pathogenesis of HF, the activation of the immune system leads to a progressive and redundant release of proinflammatory cytokines responsible for a variety of deleterious effects in heart failure, such as endothelial dysfunction, apoptosis of myocytes, activation of MMPs (Matrix Metallo Proteinases) and oxidative stress, with the result of decreased inotropism and clinical syndrome such as pulmonary edema,. The condition of oxidative stress induces the expression of genes coding for the proteins inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1). Twenty-five hospitalized cardiology patients with symptomatic acute congestive HF (NYHA Class III-IV) and impaired left ventricular (LV) function (ejection fraction less than 35 percent) were included in the study. The aim of this study was to evaluate the cytokines plasma concentrations and the expression and activity of iNOS and HO-1 proteins in peripheral blood mononuclear cell (PBMC) extracted from patients in comparison to control group. In ACHF; left ventricular ejection fraction (LVEF) percent was reduced. Furthermore; iNOS and HO-1 expression and cytokines plasma levels were significantly higher in patients with ACHF as compared to controls group. Moreover the enzyme activity presents an opposite trend compared to that obtained in the analysis of the transcript and proteins. Our studies suggest a negative feedback interaction between iNOS and HO-1 important in the physiopathology of heart failure that could be considered a good candidate as a future therapeutic target for the development of new drugs.
Assuntos
Insuficiência Cardíaca/fisiopatologia , Heme Oxigenase-1/fisiologia , Leucócitos Mononucleares/metabolismo , Óxido Nítrico Sintase Tipo II/fisiologia , Doença Aguda , Idoso , Retroalimentação Fisiológica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Função Ventricular EsquerdaRESUMO
During the past decade, a great deal of data has accumulated supporting the notion that cytokines interact to regulate several aspects of social and emotional behaviour. There are reports of a positive correlation between cytokine levels and aggressive behaviour in healthy populations, and clinical reports describe an increase of aggressive traits in patients who receive cytokine immunotherapy. Interleukin-1beta released during an immune response acts as messenger that helps to modulate behaviour by influencing relevant neurotransmitter systems, and in some cases, by directly acting within the brain. In this site, IL-1beta exerts its actions by acting through 5-HT2 and IL-1 Type I receptors in hypothalamus or by potentially indirect routes, including activation of sensory afferents, and stimulation of cytokine release by brain endothelial cells. This review reports research investigating the relationship between IL-1beta, and the immune and central nervous systems involving or potentially involving defensive aggressive behaviour.
Assuntos
Agressão , Mecanismos de Defesa , Hipotálamo/imunologia , Interleucina-1beta/imunologia , Receptores Tipo I de Interleucina-1/imunologia , Serotonina/imunologia , Transmissão Sináptica/imunologia , Humanos , Hipotálamo/metabolismo , Interleucina-1beta/metabolismo , Receptores Tipo I de Interleucina-1/metabolismo , Serotonina/metabolismoRESUMO
BACKGROUND: Extremely low frequency (ELF) electromagnetic fields (EMF) are known to produce a variety of biological effects. Clinical studies are ongoing using EMF in healing of bone fractures and skin wounds. However, little is known about the mechanisms of action of ELF-EMF. Several studies have demonstrated that expression and regulation of nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2) are vital for wound healing; however, no reports have demonstrated a direct action of ELF-EMF in the modulation of these inflammatory molecules in human keratinocytes. OBJECTIVES: The present study analysed the effect of ELF-EMF on the human keratinocyte cell line HaCaT in order to assess the mechanisms of action of ELF-EMF and to provide further support for their therapeutic use in wound healing. METHODS: Exposed HaCaT cells were compared with unexposed control cells. At different exposure times, expression of inducible NOS (iNOS), endothelial NOS (eNOS) and COX-2 was evaluated by Western blot analysis. Modulation of iNOS and eNOS was monitored by evaluation of NOS activities, production of nitric oxide (NO) and O(2)(-) and expression of activator protein 1 (AP-1). In addition, catalase activity and prostaglandin (PG) E(2) production were determined. Effects of ELF-EMF on cell growth and viability were monitored. RESULTS: The exposure of HaCaT cells to ELF-EMF increased iNOS and eNOS expression levels. These ELF-EMF-dependent increased expression levels were paralled by increased NOS activities, and increased NO production. In addition, higher levels of AP-1 expression as well as a higher cell proliferation rate were associated with ELF-EMF exposure. In contrast, ELF-EMF decreased COX-2 expression, PGE(2) production, catalase activity and O(2)(-) production. CONCLUSIONS: Mediators of inflammation, such as reactive nitrogen and PGE(2), and keratinocyte proliferation are critical for the tissue regenerative processes. The ability of ELF-EMF to upmodulate NOS activities, thus nitrogen intermediates, as well as cell proliferation, and to downregulate COX-2 expression and the downstream intermediate PGE(2), highlights the potential therapeutic role of ELF-EMF in wound healing processes.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Queratinócitos/metabolismo , Magnetoterapia/métodos , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Cicatrização , Linhagem Celular , Proliferação de Células , Campos Eletromagnéticos , HumanosRESUMO
Verbascum mallophorum is part of a large family of Scrophulariaceae consisting of more than 360 species. Verbascum mallophorums contains diverse polysaccharides, iroid glycosides, flavonoids, saponins, volatile oils and phenylentanoids. Verbascum has been used in popular medicine for treating wounds, chilblains, respiratory ailments, acne and arthritic disturbances. Inducible nitric oxide synthase (iNOS) represents one of the three isoforms that produce nitric oxide using L-arginine as a substrate in response to an increase in superoxide anion activated by NF-kappaB. It is implicated in different pathophysiological events and its expression increases greatly during an inflammatory process due to oxidative stress. In our study we reproduced an inflammatory state by treating THP-1 cells (human myelomonocytic leukaemia) with pro-inflammatory stimuli, such as LPS and IFN-gamma, obtaining an up-regulation both in the expression and in the activity of iNOS. The aim of our work is to investigate the possible antiinflammatory action of verbascoside extract from Verbascum mallophorum using a concentration of 100 muM. Our results show a significant decrease in the expression and activity of iNOS and extracellular O2- when cells were treated with verbascoside. Based on these results we hypothesize that verbascoside extract from Verbascum mallophorum has anti-inflammatory properties since it reduces the production of superoxide radicals and consequently reduces the activity of iNOS.
Assuntos
Anti-Inflamatórios/farmacologia , Verbascum/química , Western Blotting , Linhagem Celular , Citrulina/biossíntese , Densitometria , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glucosídeos/farmacologia , Humanos , Interferon gama/farmacologia , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fenóis/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxidos/metabolismoRESUMO
Erectile dysfunction (ED) is a common medical condition that affects the sexual life of millions of men worldwide. Numerous physical and psychological factors are involved in normal erectile function, including neurological, vascular, hormonal and cavernous functions. The current therapy for the condition is pharmacological and psychotherapeutic which regulates the erectile function and amplifies the NO-mediated response. The aim of this work is to test the action of three common phosphodiesterase inhibitors: Tadalafil, Sildenafil Citrate and Vardenafil at 0.05 microM on human monocytes, analyzing the expression of iNOS protein and mRNA by Western blot and rt-PCR, and production of NO by conversion of L-(2,3,4,5)-[3H]Arginine to L-(3H) citrulline. We also tested the efficiency of the antioxidant network by spectrophotometer (SOD, CAT, GPx and Gr), under normal conditions and after stimulation with LPS. The results showed an increase in ROS levels, similar for all the molecules with regard to the antioxidant enzymes. In all cases the treatment determines a response to the limited efficiency, arriving at a situation in which phosphodiesterase inhibitors + LPS clearly show oxidative stress.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/efeitos dos fármacos , Estresse Oxidativo , Inibidores de Fosfodiesterase/farmacologia , Sequência de Bases , Western Blotting , Catalase/metabolismo , Primers do DNA , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Humanos , Óxido Nítrico Sintase Tipo II/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxido Dismutase/metabolismo , Superóxidos/metabolismoRESUMO
Saliva collection is considered a non-invasive method to detect inflammatory markers in response to emotional states within natural social contexts. Numerous studies have prompted an important role of cytokines in modulating distinct aspects of social and emotional behavior. The aim of this study was to investigate the reliability of plasma and saliva as investigative tools for measure some inflammatory marker levels (CRP, IL-1ß, IL-18, and IL-6). At the same time, the relationships between these markers and emotional states in response to a socio-cognitive stress (Academic Exam, AE), were considered. It was demonstrated that the plasma and saliva concentrations of all immune-mediators analyzed were significantly related across the socio-cognitive stress. In addition, when there was a close correlation to AE, the anger state, the IL-1ß, the IL-18 salivary and plasmatic concentrations were significantly higher, while they decreased during the AE. On the other hand, the anxiety state and the IL-6 levels significantly increased throughout the AE. The IL-1ß and IL-6 were positively associated to the anger and the anxiety state, respectively. In conclusion, our data highlight that different immune markers are similarly detectable in plasma and saliva during socio-cognitive stress. Also, they could be related to different emotional responses.
Assuntos
Emoções/fisiologia , Interleucinas/sangue , Interleucinas/metabolismo , Saliva/metabolismo , Adulto , Biomarcadores/análise , Proteína C-Reativa/metabolismo , Citocinas/sangue , Humanos , Interleucina-18/sangue , Interleucina-18/metabolismo , Interleucina-1beta/sangue , Interleucina-1beta/metabolismo , Interleucina-6/sangue , Interleucina-6/metabolismo , Masculino , Reprodutibilidade dos Testes , Estresse Psicológico/sangue , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia , Adulto JovemRESUMO
OBJECTIVES: In our previous reports, we have demonstrated that extremely low-frequency electromagnetic fields (ELF-EMF) exposure enhances the proliferation of keratinocyte. The present study aimed to clarify effects of ELF-EMF on wound healing and molecular mechanisms involved, using a scratch in vitro model. MATERIALS AND METHODS: The wounded monolayer cultures of human immortalized keratinocytes (HaCaT), at different ELF-EMF and Sham exposure times were monitored under an inverted microscope. The production and expression of IL-1ß, TNF-α, IL-18 and IL-18BP were measured by enzyme-linked immunosorbent assay and quantitative real-time PCR. The activity and the expression of matrix metalloproteinases (MMP)-2/9 was evaluated by zymography and Western blot analysis, respectively. Signal transduction proteins expression (Akt and ERK) was measured by Western blot. RESULTS: The results of wound healing in vitro assay revealed a significant reduction of cell-free area time-dependent in ELF-EMF-exposed cells compared to Sham condition. Gene expression and release of cytokines analysed were significantly increased in ELF-EMF-exposed cells. Our results further showed that ELF-EMF exposure induced the activity and expressions of MMP-9. Molecular data showed that effects of ELF-EMF might be mediated via Akt and ERK signal pathway, as demonstrated using their specific inhibitors. CONCLUSIONS: Our results highlight ability of ELF-EMF to modulate inflammation mediators and keratinocyte proliferation/migration, playing an important role in wound repair. The ELF-EMF accelerates wound healing modulating expression of the MMP-9 via Akt/ERK pathway.
Assuntos
Citocinas/metabolismo , Campos Eletromagnéticos , Queratinócitos/metabolismo , Sistema de Sinalização das MAP Quinases , Metaloproteinase 9 da Matriz/metabolismo , Cicatrização , Linhagem Celular Transformada , Humanos , Inflamação/metabolismo , Inflamação/patologia , Inflamação/terapia , Queratinócitos/patologiaRESUMO
In this paper we examined the variations of plasmatic concentrations of hypoxanthine and xanthine, and their relation with other important indicators of muscular stress creatine-kinase (CK), myoglobin, uric acid, leucocytes, in prolonged, isokynetic physical exercise, performed in a concentric mode at different joint excursion. Twenty healthy male subjects performed isokinetic exercises in concentric-concentric mode, with joint excursion of 30, 60, 90 deg/sec. Blood samples were drawn at rest, immediately after exercise and after 45 min of recovery. The plasmatic concentration of hypoxanthine increased at the end of physical exercise, compared to the rest value of about 1,5 micromol/L, up to a level of greater than 19 micromol/L; the values were higher after a period of recovery of 45 min and the increase varies considerably according to the type of exercise that was performed. Myoglobin has a slight but sensible increment too, with the same trend as hypoxanthine, while CK increase without correlation to the type of exercises. The relation with other indicators of muscular activity demonstrates that in none of the different isokinetic exercises, performed at concentric mode, was there ultrastructural damage, while it is possible to come across a considerable metabolic stress, which is dissimilar in the different kinds of exercises. The results suggest that hypoxanthine can be useful in monitoring the effectiveness of a work load and the metabolic stress consequences on the muscle tissue in training or rehabilitation programs. The results also suggest that even myoglobin, at small concentrations, can have the same function.
Assuntos
Exercício Físico/fisiologia , Hipoxantina/sangue , Fadiga Muscular/fisiologia , Músculo Esquelético/metabolismo , Mioglobina/sangue , Adulto , Biomarcadores/sangue , Creatina Quinase/sangue , Creatina Quinase Forma MB/sangue , Teste de Esforço , Humanos , Contagem de Leucócitos , Contagem de Linfócitos , Masculino , Neutrófilos/citologia , Troponina I/sangue , Ácido Úrico/sangue , Xantina/sangueRESUMO
Free radical damage to many cellular components has been proposed as the main mechanism underlying the aging process. In the liver, NO can be generated by iNOS, but also by the constitutively expressed endothelial NOS (eNOS). iNOS enzyme appears to be expressed in liver disease such as cirrhosis and fulminant hepatitis, while the eNOS is expressed in physiological conditions. Ten young and ten old Wistar rats were sacrificed and their livers were excised. Liver sections were incubated with an anti-iNOS antibody of rabbit origin. RT-PCR and Western blot analysis were performed and nitric oxide activity was calculated. A significant increase of iNOS immunoreactivity was seen in the aged liver sections versus young liver sections. iNOS protein is expressed in greater quantities in the aged group, compared to the young group. In this study we show, for the first time, that aging in the rat liver is accompanied by a spontaneous induction of iNOS mRNA, high levels of iNOS protein and immunohistochemistry/image analysis.
Assuntos
Envelhecimento/metabolismo , Fígado/enzimologia , Óxido Nítrico Sintase Tipo II/metabolismo , Animais , Arginina/metabolismo , Western Blotting , Citrulina/biossíntese , Expressão Gênica , Imuno-Histoquímica , Rim/enzimologia , Masculino , Óxido Nítrico Sintase Tipo II/genética , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Executive Functions (EFs) involve a set of high cognitive abilities impairment which have been successfully related to a redox omeostasis imbalance in several psychiatric disorders. Firstly, we aimed to investigate the relationship between executive functioning and some oxidative metabolism parameters in Peripheral Blood Mononuclear Cells (PBMCs) from healthy adult samples. The Brown Attention-Deficit Disorder Scales were administered to assess five specific facets of executive functioning. Total superoxide anion production, Super Oxide Dismutase (SOD), Catalase (CAT), Glutathione Reductase (GR) and Glutathione Peroxidase (GPx) activities were evaluated on proteins extracted from the PBMCs. We found significant positive correlations between superoxide anion production and the total score of the 'Brown' Scale and some of its clusters. The GPx and CAT activities were negatively associated with the total score and some clusters. In a linear regression analysis, these biological variables were indicated as the most salient predictors of the total score, explaining the 24% variance (adjusted R(2)=0.24, ANOVA, p<.001). This study provides novel evidence that Executive Functions have underpinnings in the oxidative metabolism, as ascertained in healthy subjects.
Assuntos
Antioxidantes/metabolismo , Função Executiva , Leucócitos Mononucleares/metabolismo , Superóxidos/metabolismo , Adulto , Catalase/sangue , Feminino , Glutationa Peroxidase/sangue , Glutationa Redutase/sangue , Humanos , Leucócitos Mononucleares/enzimologia , Masculino , Superóxido Dismutase/sangue , Adulto JovemRESUMO
Extremely low frequency electromagnetic fields (ELF-EMF) have been found to produce a variety of biological effects. These effects of ELF-EMF depend upon frequency, amplitude, and length of exposure, and are also related to intrinsic susceptibility and responsiveness of different cell types. Although the mechanism of this interaction is still obscure, ELF-EMF can influence cell proliferation, differentiation, cell cycle, apoptosis, DNA replication and protein expression. The aim of this study was to estimate various kinetic constants of catalase, cytochrome P450 and inducible nitric oxide synthase in response to ELF-EMF exposure in human HaCaT and THP-1 cell lines. In order to evaluate the effect of ELF-EMF on the modulation of cellular responses to an inflammatory stimulus, both cell lines were treated with lipopolysaccharide. To the best of our knowledge there is no available report on such type of kinetic study of selected enzymes in response to ELF-EMF in these cell lines. Therefore, the current study may reveal novel mechanism of ELFEMF biological interaction with the enzymological and hormonal systems of living organisms. These new insights may be important for ELF-EMF application particularly for wound healing, tissue regeneration, Parkinson's and Alzheimer's diseases.
Assuntos
Catalase/farmacocinética , Sistema Enzimático do Citocromo P-450/farmacocinética , Campos Eletromagnéticos , Óxido Nítrico Sintase Tipo II/farmacocinética , Linhagem Celular Transformada , Linhagem Celular Tumoral , Ativação Enzimática/fisiologia , Humanos , CinéticaRESUMO
Addition of a saturated fatty acid (SFA) induced a strong increase in heat shock (HS) mRNA transcription when cells were heat-shocked at 37 degrees C, whereas treatment with an unsaturated fatty acid (UFA) reduced or eliminated the level of HS gene transcription at 37 degrees C. Transcription of the delta 9-desaturase gene (Ole1) of Histoplasma capsulatum, whose gene product is responsible for the synthesis of UFA, is up-regulated in a temperature-sensitive strain. We show that when the L8-14C mutant of Saccharomyces cerevisiae, which has a disrupted Ole1 gene, is complemented with its own Ole1 coding region under control of its own promoter or Ole1 promoters of H. capsulatum, the level of HS gene transcription depends on the activity of the promoters. Fluorescence anisotropy of mitochondrial membranes of completed strains corresponded to the different activity of the Ole1 promoter used. We propose that the SFA/UFA ratio and perturbation of membrane lipoprotein complexes are involved in the perception of rapid temperature changes and under HS conditions disturbance of the preexisting membrane physical state causes transduction of a signal that induces transcription of HS genes.
Assuntos
Ácidos Graxos não Esterificados/farmacologia , Proteínas de Choque Térmico/biossíntese , Histoplasma/metabolismo , Mitocôndrias/metabolismo , Saccharomyces cerevisiae/metabolismo , Estearoil-CoA Dessaturase/biossíntese , Transcrição Gênica , Northern Blotting , Genes Fúngicos , Teste de Complementação Genética , Histoplasma/efeitos dos fármacos , Temperatura Alta , Membranas Intracelulares/metabolismo , Mitocôndrias/efeitos dos fármacos , Dados de Sequência Molecular , Ácido Oleico , Ácidos Oleicos/farmacologia , Fosforilação Oxidativa , Consumo de Oxigênio , Ácido Palmítico , Ácidos Palmíticos/farmacologia , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , Saccharomyces cerevisiae/genética , Ácidos Esteáricos/farmacologia , Transcrição Gênica/efeitos dos fármacosRESUMO
The Cu-ATPase ATP7A (MNK) is localized in the trans-Golgi network (TGN) and relocalizes in the plasma membrane via vesicle-mediated traffic following exposure of the cells to high concentrations of copper. Rab proteins are organelle-specific GTPases, markers of different endosomal compartments; their role has been recently reviewed (Trends Cell Biol. 11(2001) 487). In this article we analyze the endosomal pathway of trafficking of the MNK protein in stably transfected clones of CHO cells, expressing chimeric Rab5-myc or Rab7-myc proteins, markers of early or late endosome compartments, respectively. We demonstrate by immunofluorescence and confocal and electron microscopy techniques that the increase in the concentration of copper in the medium (189 microM) rapidly induces a redistribution of the MNK protein from early sorting endosomes, positive for Rab5-myc protein, to late endosomes, containing the Rab7-myc protein. Cell fractionation experiments confirm these results; i.e., the MNK protein is recruited to the endosomal fraction on copper stimulation and colocalizes with Rab5 and Rab7 proteins. These findings allow the first characterization of the vesicles involved in the intracellular routing of the MNK protein from the TGN to the plasma membrane, a key mechanism allowing appropriate efflux of copper in cells grown in high concentrations of the metal.
Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Endossomos/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas rab de Ligação ao GTP/análise , Proteínas rab5 de Ligação ao GTP/análise , Adenosina Trifosfatases/genética , Animais , Biomarcadores/análise , Células CHO , Proteínas de Transporte de Cátions/genética , Compartimento Celular , Fracionamento Celular , Cobre/farmacologia , ATPases Transportadoras de Cobre , Cricetinae , Endossomos/metabolismo , Humanos , Microscopia Eletrônica , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Recombinantes de Fusão/análise , Proteínas Recombinantes de Fusão/genética , Transfecção , Proteínas rab de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/genética , proteínas de unión al GTP Rab7RESUMO
Heat shock proteins (hsps) are ubiquitous families of proteins, found in all organisms studied so far. They are highly conserved across the species barrier and serve fundamental functions in cell physiology. The term 'heat shock' was adopted because of the early observation of the heat-inducible nature of these proteins, although, as it is now realized that they can be induced by a variety of stressful stimuli, it is probably more appropriate to call them 'stress proteins'. The nomenclature of many hsps, for example hsp90, hsp70 and hsp60, reflects the approximate molecular mass of hsps within each of these families. For many bacterial and parasitic infections, hsps were first recognized as immunodominant antigens on immunoblots of extracts from the organism probed with immune sera, or in T-cell proliferation assays. They have now been identified in a range of fungal pathogens, again often linked to an immune response. In this symposium, we review the association of hsps with humoral immunity to candidosis and aspergillosis, cellular immunity to histoplasmosis, and the identification of hsp70 in another dimorphic fungus, Paracoccidioides brasiliensis. Finally, the crucial role of the membrane in setting the temperature of the heat shock response in yeasts is discussed.