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Cold atmospheric plasma is an ionized gas produced near room temperature; it generates reactive oxygen species and nitrogen species and induces physical changes, including ultraviolet, radiation, thermal, and electromagnetic effects. Several studies showed that cold atmospheric plasma could effectively provoke death in a huge amount of cell types, including neoplastic cells, via the induction of apoptosis, necrosis, and autophagy. This technique seems able to destroy tumor cells by disturbing their more susceptible redox equilibrium with respect to normal cells, but it is also able to cause immunogenic cell death by enhancing the immune response, to decrease angiogenesis, and to provoke genetic and epigenetics mutations. Solutions activated by cold gas plasma represent a new modality for treatment of less easily reached tumors, or hematological malignancies. Our review reports on accepted knowledge of cold atmospheric plasma's effect on hematological malignancies, such as acute and chronic myeloid leukemia and multiple myeloma. Although relevant progress was made toward understanding the underlying mechanisms concerning the efficacy of cold atmospheric plasma in hematological tumors, there is a need to determine both guidelines and safety limits that guarantee an absence of long-term side effects.
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Industrialization has resulted in a massive increase in garbage output, which is frequently discharged or stored in waterways like rivers and seas. Due to their toxicity, durability, bioaccumulation, and biomagnification, heavy metals (such as mercury, cadmium, and lead) have been identified as strong biological poisons. Their presence in the aquatic environment has the potential to affect water quality parameters and aquatic life in general. Teleosts' histopathology provides a sensitive indicator of pollutant-induced stress, because their organs have a central role in the transformation of different active chemical compounds in the aquatic environment. In particular, the gills, kidneys, and liver are placed at the center of toxicological studies. The purpose of this study is to examine the morphological changes caused by heavy metals in the kidney and gills of Boops boops, with a focus on melanomacrophages centers (MMCs) and rodlet cells (RCs) as environmental biomarkers, using histological and histochemical stainings (hematoxylin/eosin, Van Gieson trichrome, Periodic Acid Schiff reaction, and Alcian Blue/PAS 2.5), and immunoperoxidase methods. Our findings show an increase of MMCs and RCs linked to higher exposure to heavy metals, confirming the role of these aggregates and cells as reliable biomarkers of potential aquatic environmental changes reflected in fish fauna. The cytological study of RCs and MMCs could be important in gaining a better understanding of the complicated immune systems of teleosts.
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Exosomes are small membrane vesicles of endocytic origin containing cytokines, RNAs, growth factors, proteins, lipids, and metabolites. They have been identified as fundamental intercellular communication controllers in several diseases and an enormous volume of data confirmed that exosomes could either sustain or inhibit tumor onset and diffusion in diverse solid and hematological malignancies by paracrine signaling. Thus, exosomes might constitute a promising cell-free tumor treatment alternative. This review focuses on the effects of exosomes in the treatment of tumors, by discussing the most recent and promising data from in vitro and experimental in vivo studies and the few existing clinical trials. Exosomes are extremely promising as transporters of drugs, antagomir, genes, and other therapeutic substances that can be integrated into their core via different procedures. Moreover, exosomes can augment or inhibit non-coding RNAs, change the metabolism of cancer cells, and modify the function of immunologic effectors thus modifying the tumor microenvironment transforming it from pro-tumor to antitumor milieu. Here, we report the development of currently realized exosome modifiers that offer indications for the forthcoming elaboration of other more effective methods capable of enhancing the activity of the exosomes.
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Exossomos , Neoplasias Hematológicas , Neoplasias , Comunicação Celular , Exossomos/metabolismo , Neoplasias Hematológicas/metabolismo , Neoplasias Hematológicas/terapia , Humanos , Neoplasias/patologia , Microambiente TumoralRESUMO
Raised oxidative stress and abnormal redox status are typical features of multiple myeloma cells, and the identification of the intimate mechanisms that regulate the relationships between neoplastic cells and redox homeostasis may reveal possible new anti-myeloma therapeutic targets to increase the effectiveness of anti-myeloma drugs synergistically or to eradicate drug-resistant clones while reducing toxicity toward normal cells. An alteration of the oxidative state is not only responsible for the onset of multiple myeloma and its progression, but it also appears essential for the therapeutic response and for developing any chemoresistance. Our review aimed to evaluate the literature's current data on the effects of oxidative stress on the response to drugs generally employed in the therapy of multiple myeloma, such as proteasome inhibitors, immunomodulators, and autologous transplantation. In the second part of the review, we analyzed the possibility of using other substances, often of natural origin, to modulate the oxidative stress to interfere with the progression of myelomatous disease.
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PURPOSE OF REVIEW: To provide an update on the possible role of nanoparticles as sensitizing occupational agents and on the influence of nanoparticles-exposure on the appearance/exacerbation of occupational allergy. RECENT FINDINGS: Recent case reports, epidemiological studies, and experimental investigations in cellular and animal models demonstrated the potential for nanomaterials to favor/interfere with occupational allergy. First data are emerging on the sensitizing potential of nanoparticles that can act as haptens linking to proteins, with a formation of a 'corona'. Nanoparticles with carrier protein become a complete antigen and induce specific immune response. Moreover, they act as adjuvant favoring sensitization to bound molecules. The disruption of the respiratory and skin barrier, the modulation of immune response toward Th1 or Th2 immune reaction and the interaction with immune effector cells (mast cells and eosinophil in particular) can explain the potential for nanoparticles to exacerbate pre-existing allergic conditions. SUMMARY: the exposure to nanoparticles represents a possible risk for occupational allergy both in the respiratory tract and in the skin. A deeper knowledge on the role of nanomaterials in the etiology/development of the allergic disease will allow to implement risk assessment and preventive measures for nanosafety in the contest of technological expansion.
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Hipersensibilidade , Nanopartículas , Exposição Ocupacional , Animais , Humanos , Hipersensibilidade/epidemiologia , Nanopartículas/efeitos adversos , Exposição Ocupacional/efeitos adversos , Sistema RespiratórioRESUMO
Effectual cell-to-cell communication is essential to the development and differentiation of organisms, the preservation of tissue tasks, and the synchronization of their different physiological actions, but also to the proliferation and metastasis of tumor cells. Tunneling nanotubes (TNTs) are membrane-enclosed tubular connections between cells that carry a multiplicity of cellular loads, such as exosomes, non-coding RNAs, mitochondria, and proteins, and they have been identified as the main participants in healthy and tumoral cell communication. TNTs have been described in numerous tumors in in vitro, ex vivo, and in vivo models favoring the onset and progression of tumors. Tumor cells utilize TNT-like membranous channels to transfer information between themselves or with the tumoral milieu. As a result, tumor cells attain novel capabilities, such as the increased capacity of metastasis, metabolic plasticity, angiogenic aptitude, and chemoresistance, promoting tumor severity. Here, we review the morphological and operational characteristics of TNTs and their influence on hematologic malignancies' progression and resistance to therapies, focusing on acute and chronic myeloid and acute lymphoid leukemia. Finally, we examine the prospects and challenges for TNTs as a therapeutic approach for hematologic diseases by examining the development of efficient and safe drugs targeting TNTs.
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Until now, morphological assessment with an optical or electronic microscope, fluorescence in situ hybridization, DNA sequencing, flow cytometry, polymerase chain reactions, and immunohistochemistry have been employed for leukemia identification. Nevertheless, despite their numerous different vantages, it is difficult to recognize leukemic cells correctly. Recently, the electrochemical evaluation with a nano-sensing interface seems an attractive alternative. Electrochemical biosensors measure the modification in the electrical characteristics of the nano-sensing interface, which is modified by the contact between a biological recognition element and the analyte objective. The implementation of nanosensors is founded not on single nanomaterials but rather on compilating these components efficiently. Biosensors able to identify the molecules of deoxyribonucleic acid are defined as DNA biosensors. Our review aimed to evaluate the literature on the possible use of electrochemical biosensors for identifying hematological neoplasms such as acute promyelocytic leukemia, acute lymphoblastic leukemia, and chronic myeloid leukemia. In particular, we focus our attention on using DNA electrochemical biosensors to evaluate leukemias.
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Conventional chemotherapy has partial therapeutic effects against hematological malignancies and is correlated with serious side effects and great risk of relapse. Recently, immunotherapeutic drugs have provided encouraging results in the treatment of hematological malignancies. Several immunotherapeutic antibodies and cell therapeutics are in dynamic development such as immune checkpoint blockades and CAR-T treatment. However, numerous problems restrain the therapeutic effectiveness of tumor immunotherapy as an insufficient anti-tumor immune response, the interference of an immune-suppressive bone marrow, or tumoral milieu with the discharge of immunosuppressive components, access of myeloid-derived suppressor cells, monocyte intrusion, macrophage modifications, all factors facilitating the tumor to escape the anti-cancer immune response, finally reducing the efficiency of the immunotherapy. Nanotechnology can be employed to overcome each of these aspects, therefore having the possibility to successfully produce anti-cancer immune responses. Here, we review recent findings on the use of biomaterial-based nanoparticles in hematological malignancies immunotherapy. In the future, a deeper understanding of tumor immunology and of the implications of nanomedicine will allow nanoparticles to revolutionize tumor immunotherapy, and nanomedicine approaches will reveal their great potential for clinical translation.
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Multiple myeloma (MM) is a hematological disease that is still not curable. The bone marrow milieu, with cellular and non-cellular elements, participate in the creation of a pro-tumoral environment enhancing growth and survival of MM plasma cells. Exosomes are vesicles oscillating in dimension between 50 nm and 100 nm in size that can be released by various cells and contribute to the pathogenesis and progression of MM. Exosomes enclose proteins, cytokines, lipids, microRNAs, long noncoding RNAs, and circular RNAs able to regulate interactions between MM plasma cells and adjacent cells. Through exosomes, mesenchymal stem cells confer chemoresistance to MM cells, while myeloma cells promote angiogenesis, influence immune response, cause bone lesions, and have an impact on the outcome of MM patients. In this review, we analyze the role played by exosomes in the progression of monoclonal gammopathies and the effects on the proliferation of neoplastic plasma cells, and discuss the possible employment of exosomes as potential targets for the treatment of MM patients.
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Carcinogênese/patologia , Exossomos/metabolismo , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/terapia , Humanos , Terapia de Alvo Molecular , Mieloma Múltiplo/imunologia , Neovascularização Patológica/metabolismo , PrognósticoRESUMO
Basophils and mast cells are among the principal inducers of Th2 responses and have a crucial role in allergic and anti-parasitic protective immunity. Basophils can function as antigen-presenting cells that bind antigens on their surface and boost humoral immune responses, inducing Th2 cell differentiation. Their depletion results in lower humoral memory activation and greater infection susceptibility. Basophils seem to have an active role upon immune response to SARS-CoV-2. In fact, a coordinate adaptive immune response to SARS-CoV-2 is magnified by basophils. It has been observed that basophil amount is lower during acute disease with respect to the recovery phase and that the grade of this depletion is an important determinant of the antibody response to the virus. Moreover, mast cells, present in a great quantity in the nasal epithelial and lung cells, participate in the first immune response to SARS-CoV-2. Their activation results in a hyperinflammatory syndrome through the release of inflammatory molecules, participating to the "cytokine storm" and, in a longer period, inducing pulmonary fibrosis. The literature data suggest that basophil counts may be a useful prognostic tool for COVID-19, since their reduction is associated with a worse prognosis. Mast cells, on the other hand, represent a possible therapeutic target for reducing the airway inflammation characteristic of the hyperacute phase of the disease.
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Basófilos/citologia , COVID-19/imunologia , COVID-19/fisiopatologia , Mastócitos/citologia , Imunidade Adaptativa , Animais , COVID-19/sangue , Diferenciação Celular , Citocinas/metabolismo , Granulócitos/citologia , Humanos , Hipersensibilidade/metabolismo , Sistema Imunitário , Imunidade Humoral , Imunidade Inata , Inflamação , Macrófagos/citologia , Camundongos , SARS-CoV-2 , Células Th17/citologia , Células Th2/citologiaRESUMO
BACKGROUND: The number of the applications of bismuth (Bi) is rapidly and remarkably increasing, enhancing the chance to increase the levels to which humans are normally daily exposed. The interest to Bi comes also from the potential of Bi-based nanoparticles (BiNPs) for industrial and biomedical purposes. Like other metal-based NPs used in nanomedicine, BiNPs may release ultratrace amounts of Bi ions when injected. The metabolic fate and toxicity of these ions still needs to be evaluated. At present, knowledge of Bi metabolism in laboratory animals refers almost solely to studies under unnatural "extreme" exposures, i.e. pharmacologically relevant high-doses (up to thousand mg kg-1) in relation to its medical use, or infinitesimal-doses (pg kg-1 as non-carrier-added Bi radioisotopes) for radiobiology protection, diagnostic and radiotherapeutic purposes. No specific study exists on the "metabolic patterns" in animal models exposed to levels of Bi, i.e. at "environmental dose exposure" that reflect the human daily exposure (µg kg-1). METHODOLOGY: Rats were intraperitoneally injected with 0.8⯵g Bi kg-1 bw as 205+206Bi(NO)3 alone or in combination with 59Fe for radiolabelling of iron proteins. The use of 205+206Bi radiotracers allowed the detection and measurement down to pg fg-1 of the element in the blood biochemical compartments and protein fractions as isolated by differential centrifugation, size exclusion- and ion exchange chromatography, electrophoresis, solvent extraction, precipitation and dialysis. RESULTS: 24â¯h after the administration, the blood concentration of Bi was 0.18â¯ng mL-1, with a repartition plasma/red blod cells (RBC) in a ratio of 2:1. Elution profiles of plasma from gel filtration on Sephadex G-150 showed four pools of Bi-binder proteins with different molecular sizes (> 300â¯kDa, 160â¯kDa, 70â¯kDa and < 6.5â¯kDa). In the 70â¯kDa fraction transferrin and albumin were identified as biomolecule carriers for Bi. In red blood cells, Bi was distributed between cytosol and membranes (ghosts) in a ratio of about 5:1. In the cytosol, low molecular components (LMWC) and the hemoglobin associated the Bi in a ratio of about 1.8:1. In the hemoglobin molecule, Bi was bound to the beta polypeptide chain of the globin. In the ghosts, Bi was detected at more than one site of the protein fraction, with no binding with lipids. Dialysis experiments and the consistently high recovery (80-90 %) of 206Bi from chromatography of 206Bi-containing biocomponents suggest that Bi was firmly complexed at physiological pH with a low degree of breaking during the applications of experimental protocols for the isolation of the 206Bi-biocomplexes. These latter were sensitive to acid buffer pH 5, and to the presence of complexing agents in the dialysis fluid. CONCLUSIONS: On the basis of an environmental biochemical toxicology approach, we have undertaken a study on the metabolic patterns of Bi3+ ions in rats at tissue, subcellular and molecular level with the identification of cellular Bi-binding components. As a first part of the study the present work reports the results concerned with the metabolic fate of ultratrace levels of 205+206Bi(NO)3 in the blood.
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Bismuto , Transferrina , Animais , Cromatografia em Gel , Cromatografia por Troca Iônica , Ferro , RatosRESUMO
Asbestos may cause adverse effects, but relationship between mineralogy and texture of fibres versus toxicity is still lacking. Toxicological studies can be interpreted and compared only if quantitative features of fibres are determined. Here, riebeckitic ("crocidolite") amphibole fibres were analysed by XRPD, FTIR, SEM-EDS and EMP-WDS; only crystals with stochiometry Aâ¡BNa2C(Fe2+2.5Mg0.5)CFe3+2TSi8O22W(OH)2 are present in the starting material used for the experiments. Fibres deposited from solutions of 0.1, 1, 10, 25, 50, 75 and 100mg/L were counted by image analysis using SEM images. At 0.1 and 1mg/L the fibres are well separated, whereas between 1 and 10mg/L they start to agglomerate. In-vitro tests performed on fibres deposited at the same mg/L concentrations show that the toxic potential follows a curvilinear increasing trend with a decreasing rate. Since the range of sizes of single fibres and their mineralogy are constant, this decreasing rate can be only attributed to the increasing amount of agglomerated fibres. Hence, single versus agglomerated fibre population is a factor that cannot be neglected in defining the final adverse effects of asbestos. The analytical protocol proposed here is valuable for any aero-dispersed dust, in polluted environments, as well as in the interpretation of experimental studies.
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OBJECTIVES: The inflammatory effects of organic sub-10nm particles generated and emitted from a diesel engine fueled with a biodiesel and a commercial diesel oil are analyzed in this paper. Diesel combustion is the major sources of ultrafine particles (UFP) in the environment, particularly in urbanized areas. In the last years, there is an increasing use of biomass-derived fuels because they are a renewable source of energy that may mitigate climate change through the reduction of net CO2 with respect to conventional fossil fuels. Although there is a general agreement on biofuels ability to reduce conventional pollutants, new and potentially harmful pollutants can be formed during biofuel combustion. In particular, the emission of sub-10nm particles is strongly increased with respect to that of larger soot particles. METHODS: Organic sub-10nm particles are separated from larger sizes particulate matter by collection in water suspension for toxicological and inflammatory tests. After exposure to sub-10nm particles, the effects on proliferation, apoptosis and secretion of cytokines, chemokines and growth factors networks production is analyzed in immortalized non-tumorigenic human dermal keratinocyte cell line (HaCaT) and human alveolar epithelial-like cells (A549). RESULTS AND CONCLUSION: Nanoparticles exert different cytotoxic effects in the two cell lines, suggesting that the dermal way of exposure is more sensitive than the inhalant way. These differences are most evident in the secretion of pro-inflammatory, angiogenic and proliferative cytokines and chemokines whose expression is more finely modulated in HaCaT cells compared to A-549 cells. Considering the size of these particles, it is important to promote the culture of prevention also for the dermal way in particularly exposed workers.
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Poluentes Atmosféricos/toxicidade , Gasolina/toxicidade , Tamanho da Partícula , Material Particulado/toxicidade , Emissões de Veículos/toxicidade , Células A549 , Apoptose/efeitos dos fármacos , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Nanopartículas/química , Nanopartículas/toxicidade , Proteína Killer-Antagonista Homóloga a bcl-2/genética , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismoRESUMO
OBJECTIVES: The first essential aspect for the prevention of occupational allergy is related to the accurate allergen identification and characterization. At present many efforts are made to characterize the potential for a chemical to be a sensitizing agent. METHODS: 'Omics' show great promise to identify key cellular and molecular events relevant to development of an adverse outcome pathway for respiratory sensitizers. One approach that shows promise is based on the measurement of the peptide reactivity of chemicals; the potential to form stable associations with protein/peptide being a key requirement for the induction of sensitization. RESULTS: Sensitization is a dose-related phenomenon, therefore the lower the exposure the lower the risk of sensitization. CONCLUSIONS: In any way, establishing occupational exposure limits for chemical allergens presents numerous difficulties. Therefore it is important using alternative exposure recommendations and risk management practices, including medical surveillance and tertiary prevention, to aid in protecting workers from exposures to allergens.
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Alérgenos/imunologia , Hipersensibilidade/imunologia , Exposição Ocupacional/efeitos adversos , Gestão de Riscos/métodos , Humanos , Hipersensibilidade/prevenção & controle , Doenças Profissionais/imunologia , Doenças Profissionais/prevenção & controle , Peptídeos/imunologia , Proteínas/imunologia , Medição de Risco/métodosRESUMO
While nanotechnology is growing exponentially, the knowledge of the impact of nanoparticles (NPs) on public health and the environment is limited so far. Current nanomaterial research is focused on the applications of nanotechnology, whereas there is little information on exposure assessment and risk characterization associated with NPs. Therefore, it is essential that the factors influencing NPs associated hazards be studied. This review seeks to survey and evaluate the current literature in order to better understand the impact of both airborne and engineered NPs exposure, the mechanisms at the cellular level, and the factors influencing their immunotoxicity. In fact, NPs do have immunotoxicological significance, as immune cells in the bloodstream and tissues do act to eliminate or interact with NPs.Proper characterization of the NPs as well as understanding the processes occurring on the NPs surface when in contact with biological systems is crucial to predict or exclude toxicological effects.
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Exposição Ambiental/efeitos adversos , Imunotoxinas/efeitos adversos , Imunotoxinas/química , Nanopartículas/efeitos adversos , Nanopartículas/química , Humanos , Saúde PúblicaRESUMO
Almost all people in developed countries are exposed to metal nanoparticles (MeNPs) that are used in a large number of applications including medical (for diagnostic and therapeutic purposes). Once inside the body, absorbed by inhalation, contact, ingestion and injection, MeNPs can translocate to tissues and, as any foreign substance, are likely to encounter the innate immunity system that represent a non-specific first line of defense against potential threats to the host. In this review, we will discuss the possible effects of MeNPs on various components of the innate immunity (both specific cells and barriers). Most important is that there are no reports of immune diseases induced by MeNPs exposure: we are operating in a safe area. However, in vitro assays show that MeNPs have some effects on innate immunity, the main being toxicity (both cyto- and genotoxicity) and interference with the activity of various cells through modification of membrane receptors, gene expression and cytokine production. Such effects can have both negative and positive relevant impacts on humans. On the one hand, people exposed to high levels of MeNPs, as workers of industries producing or applying MeNPs, should be monitored for possible health effects. On the other hand, understanding the modality of the effects on immune responses is essential to develop medical applications for MeNPs. Indeed, those MeNPs that are able to stimulate immune cells could be used to develop of new vaccines, promote immunity against tumors and suppress autoimmunity.
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The inherent toxicity of many metal compounds, together with their widespread environmental distribution, raises concerns of potential health hazards. Little is known about the impact of these important environmental toxicants on adult stem/progenitor cells, necessary for tissue homeostasis and repair. We recently reported that autophagy is implicated in the response of hematopoietic stem/progenitor cells to toxic concentrations of hexavalent chromium (Cr[VI]) and cadmium (Cd), two well known carcinogenic heavy metal cations. Autophagy may lead to cell death if carried out too extensively, but also acts as a survival pathway in cells under stress. In stem/progenitor cells, an autophagic phenotype could mitigate metal-induced toxicity, contributing to the conservation of tissue renewal capability. Given the key role of toxic damage to adult stem/progenitor cells in cancer, it is necessary to investigate whether autophagic responses modulate the carcinogenic potential of exposure to heavy metals during stem/progenitor cell differentiation.
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Autofagia/fisiologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/fisiologia , Metais Pesados/toxicidade , Apoptose/fisiologia , Diferenciação Celular/fisiologia , Poluentes Ambientais/toxicidade , Células-Tronco Hematopoéticas/ultraestrutura , HumanosRESUMO
Stem cells are a key target of environmental toxicants, but little is known about their toxicological responses. We aimed at developing an in-vitro model based on adult human stem cells to identify biomarkers of heavy metal exposure. To this end we investigated the responses of human CD34+ hematopoietic progenitor cells to hexavalent chromium (Cr[VI]) and cadmium (Cd). Parallel cultures of CD34+ cells isolated from umbilical cord blood were exposed for 48 h to 0.1 microM and 10 microM Cr(VI) or Cd. Cultures treated with 10 microM Cr(VI) or Cd showed marked cell loss. Ultrastructural analysis of surviving cells revealed prominent autophagosomes/autophagolysosomes, which is diagnostic of autophagy, associated with mitochondrial damage and replication, dilatation of the rough endoplasmic reticulum and Golgi complex, cytoplasmic lipid droplets and chromatin condensation. Treated cells did not show the morphologic hallmarks of apoptosis. Treatment with 0.1 microM Cr(VI) or Cd did not result in cell loss, but at the ultrastructural level cells showed dilated endoplasmic reticulum and evidence of mitochondrial damage. We conclude that autophagy is implicated in the response of human hematopoietic stem cells to toxic concentrations of Cr(VI) and Cd. Autophagy, which mediates cell survival and death under stress, deserves further evaluation to be established as biomarker of metal exposure.
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Autofagia , Sangue Fetal/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Metais Pesados/toxicidade , Antígenos CD34/imunologia , Sangue Fetal/citologia , Sangue Fetal/imunologia , Citometria de Fluxo , Células-Tronco Hematopoéticas/imunologia , Células-Tronco Hematopoéticas/ultraestrutura , Humanos , Microscopia Eletrônica de TransmissãoRESUMO
Protein-carbohydrate interactions are used for intercellular communication. Mammalian cells are known to bear a variety of glycoconjugates. Lectins, first discovered in plants, are proteins which can specifically bind carbohydrates. Given the high affinity of plant lectins for carbohydrates, they have always been important as molecular tools in the identification, purification and stimulation of specific glycoproteins on human cells. Lectins have provided important clues to the repertoire of carbohydrate structures in animal cells. The discovery of plant lectins gave a great impulse to modern glycobiology. They represent important biochemical reagents for numerous applications in the biomedical field and in research. Sequence determinations and structural characterization helped to understand the mechanism of action in many biologic systems. Plant lectins have been fundamental in human immunological studies because some of them are mitogenic/activating to lymphocytes. Understanding the molecular basis of lectin-carbohydrate interactions and of the intracellular signalling evoked holds promise for the design of novel drugs for the treatment of infectious, inflammatory and malignant diseases. It may also be of help for the structural and functional investigation of glycoconjugates and their changes during physiological and pathological processes.
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Pesquisa Biomédica , Lectinas de Plantas/genética , Lectinas de Plantas/imunologia , Glicoproteínas/metabolismo , Humanos , Indicadores e Reagentes , Ligantes , Mitógenos/genética , Neoplasias/terapia , Lectinas de Plantas/metabolismo , Lectinas de Plantas/uso terapêutico , Plantas/metabolismoRESUMO
T-cell immunoregulatory cytokines influence the persistence of hepatitis C virus (HCV) chronic infection and the extent of liver damage. Th1 cytokines positively correlate with hepatic inflammation in chronic hepatitis B virus (HBV) infection. The pro-inflammatory, cytokines IL-6 and IL-18, are involved in viral clearance and in metabolic and viral hepatic diseases, respectively. The aim of this study was to evaluate the profile of Th1/Th2 cytokines in HCV and HBV hepatitis. HBV-infected patients showed higher plasma IFN-gamma levels than the HCV+ patients or the control group (p <0.0001). Plasma TNF-alpha and IL-2 were higher in HBV+ in comparison to HCV+ patients (p <0.001) or the control group (p <0.005). Plasma IL-6 and IL-18 were higher in both groups of patients compared to the control group (p <0.04). In HCV+ and HBV+ groups, IL-6 was positively correlated with the duration of the illness (p <0.01 and <0.001, respectively) and viral load (p <0.001 and <0.001, respectively), while IL-18 was positively correlated with serum ALT activity (p <0.01 and <0.001, respectively) and serum AST activity (p <0.01 and <0.001, respectively). We found that in HCV+ and HBV+ patients there are higher levels of Th1 cytokines, particularly in the course of chronic hepatitis B, and that IL-18 and IL-6 levels may have important roles as markers of both inflammation and hepatic injury, particularly in the course of hepatitis C.