Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Adv Exp Med Biol ; 1353: 131-149, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35137372

RESUMO

INTRODUCTION: Within a short period, the coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) spread all over the globe and became the first pandemic of the present century. Early diagnostic tools and effective drugs are urgently needed to effectively manage the COVID-19 pandemic. Based on current literature, we provide recent updates on SARS-CoV-2 biology, available diagnostic methods, and therapeutic options for the management of COVID-19 pandemic. METHODS: A literature survey was done using Google and PubMed and Web of Science to summarize the current updates on this topic. RESULTS: Current coronavirus diagnostic tests are reverse transcription polymerase chain reaction (RT-PCR), real-time RT-PCR (qRT-PCR), and reverse transcription loop-mediated isothermal amplification (RT-LAMP) which detects the presence of specific genome sequence of virus. Existing antiviral drugs or new therapeutic options such as neutralizing antibody or plasma therapy are mostly used to restrict the virus growth with a limited success. CONCLUSION: As there is no specific treatment or vaccine available to limit the infection of SARS-CoV-2, we need to rely on the existing way to limit the disease. The first priority to fight COVID-19 is development of early diagnostic tools so that infected persons can be identified and further viral transmission can be blocked. Evaluation of existing drugs or identification of new therapeutic entities becomes the major challenge to deal with the present pandemic.


Assuntos
COVID-19 , Pandemias , Humanos , Técnicas de Diagnóstico Molecular , Pandemias/prevenção & controle , RNA Viral , Reação em Cadeia da Polimerase em Tempo Real , Transcrição Reversa , SARS-CoV-2 , Sensibilidade e Especificidade
2.
J Cell Physiol ; 232(7): 1845-1861, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27925208

RESUMO

Mouse mesoangioblasts are vessel-associated progenitor stem cells endowed with the ability of multipotent mesoderm differentiation. Therefore, they represent a promising tool in the regeneration of injured tissues. Several studies have demonstrated that homing of mesoangioblasts into blood and injured tissues are mainly controlled by cytokines/chemokines and other inflammatory factors. However, little is known about the molecular mechanisms regulating their ability to traverse the extracellular matrix (ECM). Here, we demonstrate that membrane vesicles released by mesoangioblasts contain Hsp70, and that the released Hsp70 is able to interact by an autocrine mechanism with Toll-like receptor 4 (TLR4) and CD91 to stimulate migration. We further demonstrate that Hsp70 has a positive role in regulating matrix metalloproteinase 2 (MMP2) and MMP9 expression and that MMP2 has a more pronounced effect on cell migration, as compared to MMP9. In addition, the analysis of the intracellular pathways implicated in Hsp70 regulated signal transduction showed the involvement of both PI3K/AKT and NF-κB. Taken together, our findings present a paradigm shift in our understanding of the molecular mechanisms that regulate mesoangioblast stem cells ability to traverse the extracellular matrix (ECM). J. Cell. Physiol. 232: 1845-1861, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Comunicação Autócrina , Movimento Celular , Espaço Extracelular/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Transdução de Sinais , Animais , Células Endoteliais , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Microdomínios da Membrana/metabolismo , Camundongos , Modelos Biológicos , Inibidor de NF-kappaB alfa , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor 4 Toll-Like/metabolismo
3.
Oncology ; 90(6): 356-62, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27104645

RESUMO

BACKGROUND: Although East Africa, like other countries in sub-Saharan Africa, has a lower incidence of breast cancer than high-income countries, the disease rate is rising steeply in Africa; it has nearly tripled in the past few decades in Uganda. There is a paucity of studies that have examined the relation between reproductive factors and breast cancer risk factors in Ugandan women. OBJECTIVE: To determine breast cancer risk factors among indigenous Ugandan women. METHODS: This is a hospital-based unmatched case-control study. Interviews were conducted between 2011 and 2012 using structured questionnaires. Patients with histology-proven breast cancer were recruited over a 2-year period. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: A total of 350 women were recruited; 113 were cases and 237 were controls. The mean age was 47.5 years (SD 14) for the cases and 45.5 years (SD 14.1) for the controls. The odds of breast cancer risk seemed lower for those who breastfed (adjusted OR = 0.04; 95% CI: 0.01, 0.18). There was no significance for early age at first full-term birth (adjusted OR = 1.96; 95% CI: 0.97, 3.96; p = 0.061), and urban residence carried no increased odds of breast cancer either (p = 0.201). CONCLUSION: Breastfeeding seems to be associated with reduced odds of breast cancer.


Assuntos
Neoplasias da Mama/epidemiologia , Adulto , Idoso , Aleitamento Materno , Neoplasias da Mama/etiologia , Neoplasias da Mama/prevenção & controle , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Idade Materna , Pessoa de Meia-Idade , Razão de Chances , Parto , História Reprodutiva , Medição de Risco , Fatores de Risco , Centros de Atenção Terciária/estatística & dados numéricos , Uganda/epidemiologia
4.
Int J Hyperthermia ; 32(1): 76-88, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26757879

RESUMO

An ever-increasing body of literature affirms the physical and biological basis for sensitisation of tumours to conventional therapies such as chemotherapy and radiation therapy by mild temperature hyperthermia. This knowledge has fuelled the efforts to attain, maintain, measure and monitor temperature via technological advances. A relatively new entrant in the field of hyperthermia is nanotechnology which capitalises on locally injected or systemically administered nanoparticles that are activated by extrinsic energy sources to generate heat. This review describes the kinds of nanoparticles available for hyperthermia generation, their activation sources, their characteristics, and the unique opportunities and challenges with nanoparticle-mediated hyperthermia.


Assuntos
Hipertermia Induzida , Nanopartículas/uso terapêutico , Animais , Ouro/uso terapêutico , Humanos , Fenômenos Magnéticos , Nanotubos de Carbono , Neoplasias/terapia
5.
BMC Complement Altern Med ; 13: 74, 2013 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-23552194

RESUMO

BACKGROUND: Several treatment alternatives are available for primary breast cancer, although those for metastatic disease or inflammation associated with tumor progression are ineffective. Therefore, there is a great need for new therapeutic alternatives capable of generating an immune response against residual tumor cells, thus contributing to eradication of micrometastases and cancer stem cells. The use of complex natural products is an excellent therapeutic alternative widely used by Chinese, Hindu, Egyptian, and ancestral Latin-American Indian populations. METHODS: The present study evaluated cytotoxic, antitumor, and tumor progression activities of a gallotannin-rich fraction derived from Caesalpinia spinosa (P2Et). The parameters evaluated in vitro were mitochondrial membrane depolarization, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and clonogenic activity. The parameters evaluated in vivo were tumor growth, leukocyte number, metastatic cell number, and cytokine production by flow cytometry. RESULTS: The in vitro results showed that the P2Et fraction induced apoptosis with mitochondrial membrane potential loss, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and decreased clonogenic capacity of 4T1 cells. In vivo, the P2Et fraction induced primary tumor reduction in terms of diameter and weight in BALB/c mice transplanted with 4T1 cells and decreased numbers of metastatic cells, mainly in the spleen. Furthermore, decreases in the number of peripheral blood leukocytes (leukemoid reaction) and interleukin 6 (IL-6) serum levels were found, which are events associated with a poor prognosis. The P2Et fraction exerts its activity on the primary tumor, reduces cell migration to distant organs, and decreases IL-6 serum levels, implying tumor microenvironment mechanisms. CONCLUSIONS: Overall, the P2Et fraction lessens risk factors associated with tumor progression and diminishes primary tumor size, showing good potential for use as an adjuvant in breast cancer ER(+) treatment.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Caesalpinia/química , Taninos Hidrolisáveis/administração & dosagem , Extratos Vegetais/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Interleucina-6/sangue , Camundongos , Camundongos Endogâmicos BALB C , Prognóstico
6.
BMC Cancer ; 12: 120, 2012 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-22452810

RESUMO

BACKGROUND: Triple-negative breast cancer (TNBC) exhibit characteristics quite distinct from other kinds of breast cancer, presenting as an aggressive disease--recurring and metastasizing more often than other kinds of breast cancer, without tumor-specific treatment options and accounts for 15% of all types of breast cancer with higher percentages in premenopausal African-American and Hispanic women. The reason for this aggressive phenotype is currently the focus of intensive research. However, progress is hampered by the lack of suitable TNBC cell model systems. METHODS: To understand the mechanistic basis for the aggressiveness of TNBC, we produced a stable TNBC cell line by sorting for 4T1 cells that do not express the estrogen receptor (ER), progesterone receptor (PgR) or the gene for human epidermal growth factor receptor 2 (HER2). As a control, we produced a stable triple-positive breast cancer (TPBC) cell line by transfecting 4T1 cells with rat HER2, ER and PgR genes and sorted for cells with high expression of ER and PgR by flow cytometry and high expression of the HER2 gene by Western blot analysis. RESULTS: We isolated tumor-initiating cells (TICs) by sorting for CD24+/CD44high/ALDH1+ cells from TNBC (TNBC-TICs) and TPBC (TPBC-TICs) stable cell lines. Limiting dilution transplantation experiments revealed that CD24+/CD44high/ALDH1+ cells derived from TNBC (TNBC-TICs) and TPBC (TPBC-TICs) were significantly more effective at repopulating the mammary glands of naïve female BALB/c mice than CD24-/CD44-/ALDH1- cells. Implantation of the TNBC-TICs resulted in significantly larger tumors, which metastasized to the lungs to a significantly greater extent than TNBC, TPBC-TICs, TPBC or parental 4T1 cells. We further demonstrated that the increased aggressiveness of TNBC-TICs correlates with the presence of high levels of mouse twenty-five kDa heat shock protein (Hsp25/mouse HspB1) and seventy-two kDa heat shock protein (Hsp72/HspA1A). CONCLUSIONS: Taken together, we have developed a TNBC-TICs model system based on the 4T1 cells which is a very useful metastasis model with the advantage of being able to be transplanted into immune competent recipients. Our data demonstrates that the TNBC-TICs model system could be a useful tool for studies on the pathogenesis and therapeutic treatment for TNBC.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral/patologia , Proteínas de Neoplasias/metabolismo , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Análise de Variância , Animais , Western Blotting , Linhagem Celular Tumoral/metabolismo , Separação Celular/métodos , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Ratos
7.
Stress ; 15(6): 637-46, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22217161

RESUMO

Activation of the in vivo stress response can facilitate antibacterial host defenses. One possible mechanism for this effect is stress-induced release of heat shock protein 72 (Hsp72) into the extracellular environment. Hsp72 is a ubiquitous cellular protein that is up-regulated in response to cellular stress, and modulates various aspects of immune function including macrophage inflammatory/bactericidal responses and T-cell function when found in the extracellular environment. The current study tested the hypothesis that in vivo extracellular Hsp72 (eHsp72) at the site of inflammation contributes to stress-induced restricted development of bacteria, and facilitated recovery from bacteria-induced inflammation, and that this effect is independent of alpha beta (αß) T cells. Male F344 rats were exposed to either inescapable electrical tail-shocks or no stress, and subcutaneously injected with Escherichia coli (ATCC 15746). The role of eHsp72 was investigated by Hsp72-immunoneutralization at the inflammatory site. The potential contribution of T cells was examined by testing male athymic (rnu/rnu) nude rats lacking mature αß T cells and heterozygous thymic intact control (rnu/+) rats. The results were that stressor exposure increased plasma concentrations of eHsp72 and facilitated recovery from bacterial inflammation. Immunoneutralization of eHsp72 at the inflammatory site attenuated this effect. Stressor exposure impacted bacterial inflammation and eHsp72 equally in both athymic and intact control rats. These results support the hypothesis that eHsp72 at the site of inflammation, and not αß T cells, contributes to the effect of stressor exposure on subcutaneous bacterial inflammation.


Assuntos
Infecções por Escherichia coli/fisiopatologia , Proteínas de Choque Térmico HSP72/metabolismo , Inflamação/microbiologia , Estresse Psicológico/fisiopatologia , Linfócitos T/fisiologia , Animais , Eletrochoque , Proteínas de Choque Térmico HSP72/sangue , Masculino , Ratos , Ratos Endogâmicos F344 , Ratos Nus
8.
Pediatr Blood Cancer ; 58(1): 104-6, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22076833

RESUMO

We report for the first time the impact of neoadjuvant oral low-dose chemotherapy consisting of oral trofosfamide, idarubicin, and etoposide (O-TIE) in the case of alveolar rhabdomyosarcoma (RMS) in the lower jaw of an 18-year-old woman at 27 weeks of gestation, without fetal complications and a highly efficient anti-tumor response. Our study suggests the possible application of O-TIE treatment in a neoadjuvant setting during pregnancy and recommends a schedule that can be considered for the treatment of patients with high-risk sarcomas who cannot be treated with intensive chemotherapy for various reasons.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Complicações Neoplásicas na Gravidez/tratamento farmacológico , Rabdomiossarcoma Alveolar/tratamento farmacológico , Administração Oral , Adolescente , Ciclofosfamida/administração & dosagem , Ciclofosfamida/análogos & derivados , Relação Dose-Resposta a Droga , Etoposídeo/administração & dosagem , Feminino , Humanos , Idarubicina/administração & dosagem , Gravidez , Prognóstico
9.
J Biol Chem ; 285(1): 349-56, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-19861412

RESUMO

Extracellular heat shock protein 72 (Hsp72; inducible form of the 70-kDa heat shock protein) plays a critical role in innate and adaptive immune responses and has shown promise as an ideal adjuvant for the optimization of antigen-specific anti-tumor vaccines. Recent studies suggest that to correctly elucidate the mechanisms by which Hsp72 exerts its beneficial effects in vitro, great care must be taken to ensure that endotoxin by-products do not invalidate the findings. In this study, we have taken advantage of the baculovirus expression vector system for production of endotoxin-free recombinant Hsp72. The coding sequence of human hsp72 was recombined into the baculovirus immediately downstream of the strong polyhedron gene promoter. Ninety-six h post-infection of Sf9 insect cells with recombinant baculovirus, maximal levels of Hsp72 protein were detected. The recombinant human Hsp72 was purified by affinity chromatography from insect cells, and purity was confirmed by SDS-PAGE and mass spectrometry. The purified human recombinant Hsp72(bv) (Hsp72 produced using the BEVS) was demonstrated to have no endotoxin contamination and was shown to have stimulated potent calcium flux in the human monocytic cell line. Furthermore, recombinant Hsp72(bv) enhanced the tolerance of neuroblastoma cells to heat stress-induced cell death and displayed classical chaperokine functions including augmentation of inflammatory cytokine productions in mouse splenocytes. The production of functional, endotoxin-free recombinant human Hsp72(bv) in insect cells is inexpensive and convenient and eliminates the need of special procedures for endotoxin depletion. Endotoxin-free recombinant human Hsp72(bv) can now be used to unlock the important role Hsp72 plays in modulating immune function.


Assuntos
Baculoviridae/genética , Proteínas de Choque Térmico HSP72/metabolismo , Insetos/citologia , Proteínas Recombinantes/metabolismo , Animais , Baculoviridae/efeitos dos fármacos , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular , Citocinas/biossíntese , Citoproteção/efeitos dos fármacos , Vetores Genéticos/genética , Proteínas de Choque Térmico HSP72/genética , Proteínas de Choque Térmico HSP72/isolamento & purificação , Proteínas de Choque Térmico HSP72/farmacologia , Resposta ao Choque Térmico/efeitos dos fármacos , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Camundongos , Neuroblastoma/patologia , Fenótipo , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Baço/efeitos dos fármacos , Baço/metabolismo
10.
Mol Cell Biochem ; 354(1-2): 291-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21523371

RESUMO

Endogenous Arf6 is a myristoylated protein mainly involved in endosomal membrane traffic and structural organization at the plasma membrane. It has been shown that Arf6 mediates cancer cell invasion and shedding of plasma membrane microvesicles derived from tumor cells. In this article, we determined that Arf6 proteins both in the GDP and GTPγS bound forms can enter cells when simply added in the cell culture medium without requiring the myristoyl group. The GTPγS bound can enter cells at a faster rate than the GDP-bound Arf6. Despite the role of the endogenous Arf6 in endocytosis and membrane trafficking, the internalization of exogenous Arf6 may involve non-endocytic processes. As protein therapeutics is becoming important in medicine, we examined the effect of the uptake of Arf6 proteins on cellular functions and determined that exogenous Arf6 inhibits proliferation, invasion, and migration of cells. Future studies of the internalization of Arf6 mutants will reveal key residues that play a role in the internalization of Arf6 and its interaction and possible structural conformations bound to the plasma membrane.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Proteínas Recombinantes/metabolismo , Fator 6 de Ribosilação do ADP , Fatores de Ribosilação do ADP/farmacologia , Animais , Células CHO , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cricetinae , Cricetulus , Endocitose , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Guanosina Difosfato/metabolismo , Heparina/farmacologia , Humanos , Proteínas Recombinantes/farmacologia
11.
Leuk Res ; 32(4): 527-34, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17543383

RESUMO

In contrast to solid tumors, leukemic blasts frequently present both Hsp70 and HLA-E on their cell surface and thereby present activating and inhibitory signals to CD94(+) NK cells. In the first 12 months after stem cell transplantation (SCT) CD94(+) NK cells clearly dominate over CD3(+)/CD16(-)/56(-) T and CD3(+)/CD16(+)/56(+) NK-like T cells. An incubation of post-SCT-derived peripheral blood lymphocytes with the Hsp70 peptide TKD and IL-15 enhances the cell surface density of CD56/CD94 and initiates the cytolytic activity of NK cells against Hsp70/HLA-E double-positive autologous and allogeneic leukemic blasts. Hsp70 was identified as the target structure for TKD-activated NK cells.


Assuntos
Proteínas de Choque Térmico HSP70/fisiologia , Células Matadoras Naturais/imunologia , Leucemia/patologia , Fragmentos de Peptídeos/fisiologia , Transplante de Células-Tronco , Antígenos CD/metabolismo , Citotoxicidade Imunológica , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Antígenos HLA/fisiologia , Antígenos de Histocompatibilidade Classe I/fisiologia , Humanos , Interleucina-15/metabolismo , Leucemia/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Células Tumorais Cultivadas , Antígenos HLA-E
12.
Novartis Found Symp ; 291: 173-9; discussion 179-83, 221-4, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18575273

RESUMO

Chaperokine is a term recently coined to better describe the dual role of extracellular heat shock protein as both chaperone and cytokine. The augmentation of intracellular Hsp72 expression has clearly been demonstrated to be cytoprotective; with the ability to activate anti-apoptotic and anti-inflammatory pathways, exerting inhibitory effects on cell cycle progression and suppressing genes important in proliferation and differentiation. On the other hand, the role of extracellular Hsp72 is only now being elucidated and has been demonstrated to play a cytostimulatory role by enhancing proinflammatory cytokine and chemokine synthesis, up-regulate co-stimulatory molecule expression, enhance the maturation of dendritic cells and promote antitumour surveillance. This paper covers the most recent advances in elucidation of the mechanism by which the chaperokine activity of Hsp72 is transduced, addresses its biological significance and, finally, covers how it is being harnessed to produce novel therapeutic agents.


Assuntos
Citocinas/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Animais , Proteínas de Choque Térmico HSP72/metabolismo , Humanos , Camundongos
13.
J Reprod Immunol ; 79(1): 12-7, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18715652

RESUMO

Exosomes are multivesicular bodies formed by inverse membrane budding into the lumen of an endocytic compartment. Fusion with the plasma membrane leads to their release into the external milieu. The incorporation of heat shock proteins into exosomes has been associated with immune regulatory activity. We have examined whether heat shock protein-containing exosomes are present in mid-trimester amniotic fluid. Exosomes were isolated from mid-trimester amniotic fluids by sequential low-speed and high-speed centrifugation followed by sucrose density gradient centrifugation. Biochemical characterization included floatation pattern in sucrose gradients, acetylcholinesterase (AChE) activity and Western blot analysis for exosome-containing proteins. Exosomes were present in each of 23 amniotic fluids tested. They banded at a density of 1.17g/ml in sucrose gradients, were positive for AChE activity and contained tubulin, the inducible 72kDa heat shock protein, Hsp72 and the constitutively expressed heat shock protein, Hsc73; they were negative for calnexin. Exosome concentrations correlated positively with the number of pregnancies. Heat shock protein-containing exosomes are constituents of mid-trimester amniotic fluids and may contribute to immune regulation within the amniotic cavity.


Assuntos
Líquido Amniótico/química , Exossomos/química , Líquido Amniótico/citologia , Líquido Amniótico/imunologia , Feminino , Proteínas de Choque Térmico/análise , Humanos , Gravidez , Segundo Trimestre da Gravidez
14.
Handb Exp Pharmacol ; (183): 111-27, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18071657

RESUMO

Researchers have only just begun to elucidate the relationship between heat shock proteins (HSP) and Toll-like receptors (TLR). HSP were originally described as an intracellular molecular chaperone of naïve, aberrantly folded, or mutated proteins and primarily implicated as a cytoprotective protein when cells are exposed to stressful stimuli. However, recent studies have ascribed novel functions to the Hsp70 protein depending on its localization: Surface-bound Hsp70 specifically activate natural killer (NK) cells, while Hsp70 released into the extracellular milieu specifically bind to Toll-like receptors (TLR) 2 and 4 on antigen-presenting cells (APC) and exerts immunoregulatory effects, including upregulation of adhesion molecules, co-stimulatory molecule expression, and cytokine and chemokine release-a process known as the chaperokine activity of Hsp70. This chapter discusses the most recent advances in the understanding of heat shock protein (HSP) and TLR interactions in general and highlights recent findings that demonstrate Hsp70 is a ligand for TLR and its biological significance.


Assuntos
Proteínas de Choque Térmico/fisiologia , Receptores Toll-Like/fisiologia , Animais , Endotoxinas/farmacologia , Proteínas de Choque Térmico/metabolismo , Humanos , Chaperonas Moleculares/fisiologia , Transdução de Sinais/fisiologia , Receptores Toll-Like/metabolismo
15.
BMC Complement Altern Med ; 8: 60, 2008 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-19017389

RESUMO

BACKGROUND: There is ethnopharmacological evidence that Petiveria alliacea can have antitumor activity; however, the mechanism of its cytotoxic activity is not well understood. We assessed multiple in vitro biological activities of an ethyl acetate soluble plant fraction over several tumor cell lines. METHODS: Tumor cell lines were evaluated using the following tests: trypan blue exclusion test, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide], flow cytometry, cytoskeleton organization analysis, cell cycle, mitochondria membrane depolarization, clonogenicity test, DNA fragmentation test and differential protein expression by HPLC-Chip/MS analysis. F4 fraction characterization was made by HPLC-MS. RESULTS: Petiveria alliacea fraction characterized by de-replication was found to alter actin cytoskeleton organization, induce G2 cell cycle arrest and cause apoptotic cell death in a mitochondria independent way. In addition, we found down regulation of cytoskeleton, chaperone, signal transduction proteins, and proteins involved in metabolic pathways. Finally up regulation of proteins involved in translation and intracellular degradation was also observed. CONCLUSION: The results of this study indicate that Petiveria alliacea exerts multiple biological activities in vitro consistent with cytotoxicity. Further studies in animal models are needed but Petiveria alliacea appears to be a good candidate to be used as an antitumor agent.


Assuntos
Antineoplásicos/farmacologia , Phytolaccaceae , Extratos Vegetais/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Actinas/efeitos dos fármacos , Animais , Morte Celular , Linhagem Celular Tumoral , Fase G2/efeitos dos fármacos , Humanos , Dose Letal Mediana , Melanoma/tratamento farmacológico , Camundongos , Camundongos Transgênicos , Mitocôndrias/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/metabolismo , Células Tumorais Cultivadas
16.
J Biosci ; 32(3): 579-84, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17536177

RESUMO

Currently two mechanisms are recognized by which heat shock proteins (HSP) are released from cells; a passive release mechanism, including necrotic cell death, severe blunt trauma, surgery and following infection with lytic viruses, and an active release mechanism which involves the non classical protein release pathway. HSPs are released both as free HSP and within exosomes. This review covers recent findings on the mechanism by which stress induces the release of HSP72 into the circulation and the biological significance of circulating HSP72 to host defense against disease.


Assuntos
Proteínas de Choque Térmico HSP72/metabolismo , Animais , Humanos , Neoplasias/metabolismo , Estresse Fisiológico
17.
Cancer Res ; 65(12): 5238-47, 2005 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-15958569

RESUMO

Detergent-soluble membrane vesicles are actively released by human pancreas (Colo-/Colo+) and colon (CX-/CX+) carcinoma sublines, differing in their capacity to present heat shock protein 70 (Hsp70)/Bag-4 on their plasma membranes. Floating properties, acetylcholine esterase activity, and protein composition characterized them as exosomes. An enrichment of Rab-4 documented their intracellular transport route from early endosomes to the plasma membrane. After solubilization, comparable amounts of cytosolic proteins, including tubulin, Hsp70, Hsc70, and Bag-4, but not ER-residing Grp94 and calnexin, were detectable in tumor-derived exosomes. However, with respect to the exosomal surface, only Colo+/CX+ but not Colo-/CX- derived exosomes were Hsp70 membrane positive. Therefore, concomitant with an up-regulated cell surface density of activation markers, migration and Hsp70 reactivity of natural killer (NK) cells was stimulated selectively by Hsp70/Bag-4 surface-positive exosomes, but not by their negative counterparts and tumor cell lysates. Moreover, the exosome-mediated lytic activity of NK cells was blockable by Hsp70-specific antibody. As already shown for TKD stimulation, NK cells preincubated with Hsp70 surface-positive exosomes initiated apoptosis in tumors through granzyme B release. In summary, our data provide an explanation how Hsp70 reactivity in NK cells is induced by tumor-derived exosomes.


Assuntos
Movimento Celular/imunologia , Neoplasias do Colo/imunologia , Proteínas de Choque Térmico HSP70/imunologia , Células Matadoras Naturais/imunologia , Neoplasias Pancreáticas/imunologia , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Vesículas Citoplasmáticas/imunologia , Vesículas Citoplasmáticas/metabolismo , Citotoxicidade Imunológica , Granzimas , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fragmentos de Peptídeos/farmacologia , Serina Endopeptidases/imunologia , Serina Endopeptidases/metabolismo
18.
Mech Ageing Dev ; 127(11): 862-8, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17027907

RESUMO

Heat shock proteins are highly conserved proteins that, when produced intracellularly, protect stress exposed cells. In contrast, extracellular heat shock protein 70 (Hsp70) has been shown to have both protective and deleterious effects. In this study, we assessed heat shock protein 70 for its potential role in human longevity. Because of the importance of HSP to disease processes, cellular protection, and inflammation, we hypothesized that: (1) Hsp70 levels in centenarians and centenarian offspring are different from controls and (2) alleles in genes associated with Hsp70 explain these differences. In this cross-sectional study, we assessed serum Hsp70 levels from participants enrolled in either the New England Centenarian Study (NECS) or the Longevity Genes Project (LGP): 87 centenarians (from LGP), 93 centenarian offspring (from NECS), and 126 controls (43 from NECS, 83 from LGP). We also examined genotypic and allelic frequencies of polymorphisms in HSP70-A1A and HSP70-A1B in 347 centenarians (266 from the NECS, 81 from the LGP), 260 NECS centenarian offspring, and 238 controls (NECS: 53 spousal controls and 106 septuagenarian offspring controls; LGP: 79 spousal controls). The adjusted mean serum Hsp70 levels (ng/mL) for the NECS centenarian offspring, LGP centenarians, LGP spousal controls, and NECS controls were 1.05, 1.13, 3.07, 6.93, respectively, suggesting that a low serum Hsp70 level is associated with longevity; however, no genetic associations were found with two SNPs within two hsp70 genes.


Assuntos
Proteínas de Choque Térmico HSP70/sangue , Longevidade/fisiologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Genótipo , Proteínas de Choque Térmico HSP70/genética , Humanos , Longevidade/genética , Masculino , Polimorfismo de Nucleotídeo Único
19.
Atherosclerosis ; 185(1): 32-8, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15993884

RESUMO

Lipid accumulation and inflammation are key hallmarks of the atherosclerotic plaque and macrophage uptake of oxidized low-density lipoprotein (oxLDL) is believed to drive these processes. Initial experiments show that supernatants from oxLDL treated macrophages could induce IL-1beta production in naïve macrophages. To search for potential paracrine mediators that could mediate this effect a DNA microarray scan of oxLDL treated human macrophages was performed. This analysis revealed that oxLDL induced activation of heat shock protein (HSP) expression. HSPs have been implicated in the development of atherosclerosis, but the exact mechanisms for this is unclear. Extracellular heat shock protein 70 (HSP70) has been shown to elicit a pro-inflammatory cytokine response in monocytes and could therefore be a potential paracrine pro-inflammatory mediator. After 24 h of oxLDL treatment there was a significant increase of HSP70 concentrations in supernatants from oxLDL treated macrophages (oxLDLsup) compared to untreated controls (P<0.05). OxLDLsup could induce both interleukin (IL)-1beta and IL-12 secretion in naïve macrophages. We also demonstrate that the effect of oxLDLsup on cytokine production and release could be blocked by inhibition of HSP70 transcription or secretion or by the use of HSP70 neutralizing antibodies. This suggests that extracellular HSP70 can mediate pro-inflammatory changes in macrophages in response to oxLDL.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Interleucina-1/biossíntese , Lipoproteínas LDL/farmacologia , Macrófagos/metabolismo , DNA/genética , Ensaio de Imunoadsorção Enzimática , Líquido Extracelular/metabolismo , Citometria de Fluxo , Proteínas de Choque Térmico HSP70/genética , Humanos , Técnicas In Vitro , Líquido Intracelular/metabolismo , Macrófagos/efeitos dos fármacos , Masculino , Mutação , Oxirredução , Reação em Cadeia da Polimerase Via Transcriptase Reversa
20.
PLoS One ; 11(3): e0149409, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26960140

RESUMO

Type 2 diabetes is a growing public health concern and accounts for approximately 90% of all the cases of diabetes. Besides insulin resistance, type 2 diabetes is characterized by a deficit in ß-cell mass as a result of misfolded human islet amyloid polypeptide (h-IAPP) which forms toxic aggregates that destroy pancreatic ß-cells. Heat shock proteins (HSP) play an important role in combating the unwanted self-association of unfolded proteins. We hypothesized that Hsp72 (HSPA1A) prevents h-IAPP aggregation and toxicity. In this study, we demonstrated that thermal stress significantly up-regulates the intracellular expression of Hsp72, and prevents h-IAPP toxicity against pancreatic ß-cells. Moreover, Hsp72 (HSPA1A) overexpression in pancreatic ß-cells ameliorates h-IAPP toxicity. To test the hypothesis that Hsp72 (HSPA1A) prevents aggregation and fibril formation, we established a novel C. elegans model that expresses the highly amyloidogenic human pro-IAPP (h-proIAPP) that is implicated in amyloid formation and ß-cell toxicity. We demonstrated that h-proIAPP expression in body-wall muscles, pharynx and neurons adversely affects C. elegans development. In addition, we demonstrated that h-proIAPP forms insoluble aggregates and that the co-expression of h-Hsp72 in our h-proIAPP C. elegans model, increases h-proIAPP solubility. Furthermore, treatment of transgenic h-proIAPP C. elegans with ADAPT-232, known to induce the expression and release of Hsp72 (HSPA1A), significantly improved the growth retardation phenotype of transgenic worms. Taken together, this study identifies Hsp72 (HSPA1A) as a potential treatment to prevent ß-cell mass decline in type 2 diabetic patients and establishes for the first time a novel in vivo model that can be used to select compounds that attenuate h-proIAPP aggregation and toxicity.


Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Diabetes Mellitus Tipo 2/terapia , Proteínas de Choque Térmico HSP72/metabolismo , Polipeptídeo Amiloide das Ilhotas Pancreáticas/química , Polipeptídeo Amiloide das Ilhotas Pancreáticas/toxicidade , Agregados Proteicos , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Sequência de Bases , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Resposta ao Choque Térmico/efeitos dos fármacos , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Polipeptídeo Amiloide das Ilhotas Pancreáticas/genética , Camundongos , Dados de Sequência Molecular , Fenótipo , Extratos Vegetais/farmacologia , Solubilidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA