Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
1.
Pharmaceutics ; 13(12)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34959459

RESUMO

Development of specific medical devices (MDs) is required to meet the healthcare needs of children and young people (CYP). In this context, MD development should address changes in growth and psychosocial maturation, physiology, and pathophysiology, and avoid inappropriate repurposing of adult technologies. Underpinning the development of MD for CYP is the need to ensure MD safety and effectiveness through pediatric MD-specific regulations. Contrary to current perceptions of limited market potential, the global pediatric healthcare market is expected to generate around USD 15,984 million by 2025. There are 1.8 billion young people in the world today; 40% of the global population is under 24, creating significant future healthcare market opportunities. This review highlights a number of technology areas that have led to successful pediatric MD, including 3D printing, advanced materials, drug delivery, and diagnostic imaging. To ensure the targeted development of MD for CYP, collaboration across multiple professional disciplines is required, facilitated by a platform to foster collaboration and drive innovation. The European Pediatric Translational Research Infrastructure (EPTRI) will be established as the European platform to support collaboration, including the life sciences industrial sector, to identify unmet needs in child health and support the development, adoption, and commercialization of pediatric MDs.

2.
Transplantation ; 103(2): 237-249, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30028414

RESUMO

No field in health sciences has more interest than organ transplantation in fostering progress in regenerative medicine (RM) because the future of no other field more than the future of organ transplantation will be forged by progress occurring in RM. In fact, the most urgent needs of modern transplant medicine, namely, more organs to satisfy the skyrocketing demand and immunosuppression-free transplantation, cannot be met in full with current technologies and are at risk of remaining elusive goals. Instead, in the past few decades, groundbreaking progress in RM is suggesting a different approach to the problem. New, RM-inspired technologies among which decellularization, 3-dimensional printing and interspecies blastocyst complementation, promise organoids manufactured from the patients' own cells and bear potential to render the use of currently used allografts obsolete. Transplantation, a field that has traditionally been immunology-based, is therefore destined to become a RM-based discipline. However, the contours of RM remain unclear, mainly due to the lack of a universally accepted definition, the lack of clarity of its potential modalities of application and the unjustified and misleading hype that often follows the reports of clinical application of RM technologies. All this generates excessive and unmet expectations and an erroneous perception of what RM really is and can offer. In this article, we will (1) discuss these aspects of RM and transplant medicine, (2) propose a definition of RM, and (3) illustrate the state of the art of the most promising RM-based technologies of transplant interest.


Assuntos
Transplante de Órgãos , Medicina Regenerativa , Alergia e Imunologia , Humanos , Impressão Tridimensional , Transplante de Células-Tronco
3.
Transplantation ; 102(8): 1223-1229, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29781950

RESUMO

Beta cell replacement has the potential to restore euglycemia in patients with insulin-dependent diabetes. Although great progress has been made in establishing allogeneic islet transplantation from deceased donors as the standard of care for those with the most labile diabetes, it is also clear that the deceased donor organ supply cannot possibly treat all those who could benefit from restoration of a normal beta cell mass, especially if immunosuppression were not required. Against this background, the International Pancreas and Islet Transplant Association in collaboration with the Harvard Stem Cell Institute, the Juvenile Diabetes Research Foundation (JDRF), and the Helmsley Foundation held a 2-day Key Opinion Leaders Meeting in Boston in 2016 to bring together experts in generating and transplanting beta cells derived from stem cells. The following summary highlights current technology, recent significant breakthroughs, unmet needs and roadblocks to stem cell-derived beta cell therapies, with the aim of spurring future preclinical collaborative investigations and progress toward the clinical application of stem cell-derived beta cells.


Assuntos
Diabetes Mellitus Tipo 1/terapia , Células Secretoras de Insulina/citologia , Transplante de Células-Tronco/métodos , Animais , Boston , Diferenciação Celular , Congressos como Assunto , Edição de Genes , Humanos , Tolerância Imunológica , Células Secretoras de Insulina/imunologia , Transplante das Ilhotas Pancreáticas , Pâncreas/citologia , Transplante de Pâncreas/métodos , Células-Tronco Pluripotentes/citologia , Doadores de Tecidos
4.
Artigo em Inglês | MEDLINE | ID: mdl-28993805

RESUMO

The commercial development of advanced therapy medicinal products (ATMPs) represents great opportunity for therapeutic innovation but is beset by many challenges for its developers. Although the ATMP field continues to progress at a rapid pace, evidenced by the increasing number of clinical trials conducted over the past few years, several factors continue to complicate the introduction of ATMPs as a curative treatment for multiple disease types, by blocking their translational pathway from research to the patient. While several recent publications (Trounson and McDonald, 2015; Abou-El-Enein et al., 2016a,b) as well as an Innovative Medicines Initiative consultation (IMI, 2016) this year have highlighted the major gaps in ATMP development, with manufacturing, regulatory, and reimbursement issues at the forefront, there remains to be formulated a coherent strategy to address these by bringing the relevant stakeholders to a single forum, whose task it would be to design and execute a delta plan to alleviate the most pressing bottlenecks. This article focuses on two of the most urgent areas in need of attention in ATMP development, namely manufacturing and reimbursement, and promotes the concept of innovation-dedicated research infrastructures to support a multi-sector approach for ensuring the successful development, entry, and ensuing survival of ATMPs in the healthcare market.

5.
Appl Ergon ; 65: 424-436, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28420483

RESUMO

This study investigates the effect of sensor placement on the analysis of trunk posture for construction activities using two off-the-shelf systems. Experiments were performed using a single-parameter monitoring wearable sensor (SPMWS), the ActiGraph GT9X Link, which was worn at six locations on the body, and a multi-parameter monitoring wearable sensor (MPMWS), the Zephyr BioHarness™3, which was worn at two body positions. One healthy male was recruited and conducted 10 experiment sessions to repeat measurements of trunk posture within our study. Measurements of upper-body thoracic bending posture during the lifting and lowering of raised deck materials in a laboratory setting were compared against video-captured observations of posture. The measurements from the two sensors were found to be in agreement during slow-motion symmetric bending activities with a target bending of ≤45°. However, for asymmetric bending tasks, when the SPMWS was placed on the chest, its readings were substantially different from those of the MPMWS worn on the chest or under the armpit.


Assuntos
Técnicas Biossensoriais/instrumentação , Indústria da Construção , Postura/fisiologia , Dispositivos Eletrônicos Vestíveis , Trabalho/fisiologia , Adulto , Fenômenos Biomecânicos , Voluntários Saudáveis , Humanos , Remoção , Masculino , Tórax
7.
Int J Biochem Cell Biol ; 50: 112-22, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24594363

RESUMO

To clarify the role of HDACs in erythropoiesis, expression, activity and function of class I (HDAC1, HDAC2, HDAC3) and class IIa (HDAC4, HDAC5) HDACs during in vitro maturation of human erythroblasts were compared. During erythroid maturation, expression of HDAC1, HDAC2 and HDAC3 remained constant and activity and GATA1 association (its partner of the NuRD complex), of HDAC1 increased. By contrast, HDAC4 content drastically decreased and HDAC5 remained constant in content but decreased in activity. In erythroid cells, pull down experiments identified the presence of a novel complex formed by HDAC5, GATA1, EKLF and pERK which was instead undetectable in cells of the megakaryocytic lineage. With erythroid maturation, association among HDAC5, GATA1 and EKLF persisted but levels of pERK sharply decreased. Treatment of erythroleukemic cells with inhibitors of ERK phosphorylation reduced by >90% the total and nuclear content of HDAC5, GATA1 and EKLF, suggesting that ERK phosphorylation is required for the formation of this complex. Based on the function of class IIa HDACs as chaperones of other proteins to the nucleus and the erythroid-specificity of HDAC5 localization, this novel HDAC complex was named nuclear remodeling shuttle erythroid (NuRSERY). Exposure of erythroid cells to the class II-selective HDAC inhibitor (HDACi) APHA9 increased γ/(γ+ß) globin expression ratios (Mai et al., 2007), suggesting that NuRSERY may regulate globin gene expression. In agreement with this hypothesis, exposure of erythroid cells to APHA9 greatly reduced the association among HDAC5, GATA1 and EKLF. Since exposure to APHA9 did not affect survival rates or p21 activation, NuRSERY may represent a novel, possibly less toxic, target for epigenetic therapies of hemoglobinopaties and other disorders.


Assuntos
Células Eritroides/metabolismo , Fator de Transcrição GATA1/metabolismo , Histona Desacetilases/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , eIF-2 Quinase/metabolismo , Diferenciação Celular/fisiologia , Núcleo Celular/metabolismo , Células Cultivadas , Citoplasma/metabolismo , Eritroblastos/citologia , Eritroblastos/enzimologia , Eritroblastos/patologia , Células Eritroides/citologia , Células Eritroides/enzimologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/enzimologia , Células-Tronco Hematopoéticas/metabolismo , Humanos , Células K562 , Megacariócitos/citologia , Megacariócitos/enzimologia , Megacariócitos/metabolismo , Fosforilação
9.
Am J Nucl Med Mol Imaging ; 3(2): 166-74, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23526583

RESUMO

Recent advances in molecular and cellular biology have facilitated the discovery of the key molecular drivers of major diseases. This knowledge raised some optimism in the beginning of this century, yet its impact on disease prevention, diagnosis and targeted intervention remains low. At the same time the pharmaceutical industry is facing the dual challenges of a dwindling drug pipeline and ever increasing cost of drug development. It is against this background that a number of European countries decided to establish EATRIS, the European Advanced Translational Research InfraStructure in Medicine. EATRIS aims for faster and more efficient translation of basic research into innovative products, by providing academia and industry access to the state-of-the-art expertise and highly capital-intensive facilities residing in Europe's top translational research centers and hospitals. To this end, EATRIS formed product groups that provide translational services in the fields of development and supply of (1) molecular imaging and tracing, (2) vaccines, (3) biomarkers, (4) small molecules and (5) advanced therapeutic medicinal products. Herein we describe the background, goals, functions and structure of EATRIS. As an example, it will be described how EATRIS centers involved in imaging and tracing might contribute to more efficient drug development and personalized medicine.

10.
Adv Biochem Eng Biotechnol ; 130: 287-99, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22842860

RESUMO

The use of stem cells for therapeutic purposes is regulated by two overlapping sets of rules. If used for transplantation, stem cells are covered by the collection, traceability and technical aspects of three European directives. When the stem cells are used as part of a medicinal product, they are covered by the legislation on pharmaceutical production and marketing authorization-in particular, by Regulation 1394/2007/EC.

11.
J Constr Eng Manag ; 139(7): 858-869, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25018582

RESUMO

In the feasibility stage, the correct prediction of construction costs ensures that budget requirements are met from the start of a project's lifecycle. A very common approach for performing quick-order-of-magnitude estimates is based on using Location Cost Adjustment Factors (LCAFs) that compute historically based costs by project location. Nowadays, numerous LCAF datasets are commercially available in North America, but, obviously, they do not include all locations. Hence, LCAFs for un-sampled locations need to be inferred through spatial interpolation or prediction methods. Currently, practitioners tend to select the value for a location using only one variable, namely the nearest linear-distance between two sites. However, construction costs could be affected by socio-economic variables as suggested by macroeconomic theories. Using a commonly used set of LCAFs, the City Cost Indexes (CCI) by RSMeans, and the socio-economic variables included in the ESRI Community Sourcebook, this article provides several contributions to the body of knowledge. First, the accuracy of various spatial prediction methods in estimating LCAF values for un-sampled locations was evaluated and assessed in respect to spatial interpolation methods. Two Regression-based prediction models were selected, a Global Regression Analysis and a Geographically-weighted regression analysis (GWR). Once these models were compared against interpolation methods, the results showed that GWR is the most appropriate way to model CCI as a function of multiple covariates. The outcome of GWR, for each covariate, was studied for all the 48 states in the contiguous US. As a direct consequence of spatial non-stationarity, it was possible to discuss the influence of each single covariate differently from state to state. In addition, the article includes a first attempt to determine if the observed variability in cost index values could be, at least partially explained by independent socio-economic variables.

12.
Stem Cells Int ; 2011: 602483, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21961017

RESUMO

In Human Erythroid Massive Amplification (HEMA) cultures, AB mononuclear cells (MNC) generate 1-log more erythroid cells (EBs) than the corresponding CD34(pos) cells, suggesting that MNC may also contain CD34(neg) HPC. To clarify the phenotype of AB HPC which generate EBs in these cultures, flow cytometric profiling for CD34/CD36 expression, followed by isolation and functional characterization (colony-forming-ability in semisolid-media and fold-increase in HEMA) were performed. Four populations with erythroid differentiation potential were identified: CD34(pos)CD36(neg) (0.1%); CD34(pos)CD36(pos) (barely detectable-0.1%); CD34(neg)CD36(low) (2%) and CD34(neg)CD36(neg) (75%). In semisolid-media, CD34(pos)CD36(neg) cells generated BFU-E and CFU-GM (in a 1 : 1 ratio), CD34(neg)CD36(neg) cells mostly BFU-E (87%) and CD34(pos)CD36(pos) and CD34(neg)CD36(low) cells were not tested due to low numbers. Under HEMA conditions, CD34(pos)CD36(neg), CD34(pos)CD36(pos), CD34(neg)CD36(low) and CD34(neg)CD36(neg) cells generated EBs with fold-increases of ≈9,000, 100, 60 and 1, respectively, and maturation times (day with >10% CD36(high)CD235a(high) cells) of 10-7 days. Pyrenocytes were generated only by CD34(neg)/CD36(neg) cells by day 15. These results confirm that the majority of HPC in AB express CD34 but identify additional CD34(neg) populations with erythroid differentiation potential which, based on differences in fold-increase and maturation times, may represent a hierarchy of HPC present in AB.

13.
Stem Cells Int ; 2011: 673752, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21912558

RESUMO

Ex vivo expanded erythroblasts (EBs) may serve as advanced transfusion products provided that lodgment occurs in the macrophage-niche of the marrow permitting maturation. EBs expanded from adult and cord blood expressed the receptors (CXCR4, VLA-4, and P-selectin ligand 1) necessary for interaction with macrophages. However, 4-days following transfusion to intact NOD/SCID/IL2Rγ(null) mice, CD235a(pos) EBs were observed inside CD235a(neg) splenic cells suggesting that they underwent phagocytosis. When splenectomized and intact NOD/SCID/IL2Rγ(null) mice were transfused using retrovirally labeled human EBs, human cells were visualized by bioluminescence imaging only in splenectomized animals. Four days after injection, human CD235a(pos) cells were detected in marrow and liver of splenectomized mice but only in spleen of controls. Human CD235a(pos) erythrocytes in blood remained low in all cases. These studies establish splenectomized NOD/SCID/IL2Rγ(null) mice as a suitable model for tracking and quantification of human EBs in vivo.

14.
Blood Cells Mol Dis ; 47(3): 182-97, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21775174

RESUMO

The number of erythroblasts generated ex-vivo under human-erythroid massive-amplification conditions by mononuclear cells from one unit of adult blood (~10(10)) are insufficient for transfusion (~10(12) red cells), emphasizing the need for studies to characterize cellular interactions during culture to increase erythroblast production. To identify the cell populations which generate erythroblasts under human-erythroid-massive-amplification conditions and the factors that limit proliferation, day 10 non-erythroblasts and immature- and mature-erythroblasts were separated by sorting, labelled with carboxyfluorescein-diacetate-succinimidyl-ester and re-cultured either under these conditions (for proliferation, maturation and/or apoptosis/autophagy determinations) or in semisolid media (for progenitor cell determination). Non-erythroblasts contained 54% of the progenitor cells but did not grow under human-erythroid-massive-amplification conditions. Immature-erythroblasts contained 25% of the progenitor cells and generated erythroblasts under human-erythroid-massive-amplification conditions (FI at 48 h=2.57±1.15). Mature-erythroblasts did not generate colonies and died in human-erythroid-massive-amplification conditions. In sequential sorting/re-culture experiments, immature-erythroblasts retained the ability to generate erythroblasts for 6 days and generated 2-5-fold more cells than the corresponding unfractionated population, suggesting that mature-erythroblasts may limit erythroblast expansion. In co-cultures of carboxyfluorescein-diacetate-succinimidyl-ester-labelled-immature-erythroblasts with mature-erythroblasts at increasing ratios, cell numbers did not increase and proliferation, maturation and apoptotic rates were unchanged. However, Acridine Orange staining (a marker for autophagic death) increased from ~3.2% in cultures with immature-erythroblasts alone to 14-22% in cultures of mature-erythroblasts with and without immature-erythroblasts. In conclusion, these data identify immature-erythroblasts as the cells that generate additional erythroblasts in human-erythroid-massive-amplification cultures and autophagy as the leading cause of death limiting the final cellular output of these cultures.


Assuntos
Autofagia/fisiologia , Técnicas de Cultura de Células/métodos , Eritroblastos/citologia , Eritropoese/fisiologia , Células-Tronco Hematopoéticas/citologia , Anemia/patologia , Apoptose/fisiologia , Transfusão de Sangue/métodos , Diferenciação Celular , Proliferação de Células , Separação Celular , Sobrevivência Celular , Células Cultivadas , Técnicas de Cocultura , Eritrócitos/citologia , Glucocorticoides/farmacologia , Substâncias de Crescimento/farmacologia , Humanos , Imunofenotipagem
15.
Blood ; 118(2): 425-36, 2011 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-21355091

RESUMO

Glucocorticoid receptor (GR) agonists increase erythropoiesis in vivo and in vitro. To clarify the effect of the dominant negative GRß isoform (unable to bind STAT-5) on erythropoiesis, erythroblast (EB) expansion cultures of mononuclear cells from 18 healthy (nondiseased) donors (NDs) and 16 patients with polycythemia vera (PV) were studied. GRß was expressed in all PV EBs but only in EBs from 1 ND. The A3669G polymorphism, which stabilizes GRß mRNA, had greater frequency in PV (55%; n = 22; P = .0028) and myelofibrosis (35%; n = 20) patients than in NDs (9%; n = 22) or patients with essential thrombocythemia (6%; n = 15). Dexamethasone stimulation of ND cultures increased the number of immature EBs characterized by low GATA1 and ß-globin expression, but PV cultures generated great numbers of immature EBs with low levels of GATA1 and ß-globin irrespective of dexamethasone stimulation. In ND EBs, STAT-5 was not phosphorylated after dexamethasone and erythropoietin treatment and did not form transcriptionally active complexes with GRα, whereas in PV EBs, STAT-5 was constitutively phosphorylated, but the formation of GR/STAT-5 complexes was prevented by expression of GRß. These data indicate that GRß expression and the presence of A3669G likely contribute to development of erythrocytosis in PV and provide a potential target for identification of novel therapeutic agents.


Assuntos
Células Eritroides/metabolismo , Células Eritroides/patologia , Policitemia Vera/genética , Policitemia Vera/patologia , Receptores de Glucocorticoides/genética , Sequência de Bases , Técnicas de Cultura de Células , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Dexametasona/farmacologia , Células Eritroides/efeitos dos fármacos , Expressão Gênica , Genes Dominantes/genética , Genes Dominantes/fisiologia , Glucocorticoides/farmacologia , Humanos , Janus Quinase 2/genética , Modelos Biológicos , Dados de Sequência Molecular , Policitemia/genética , Policitemia/patologia , Policitemia Vera/metabolismo , Polimorfismo de Nucleotídeo Único/fisiologia , Isoformas de Proteínas/genética
16.
Transfusion ; 51(9): 1985-94, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21418078

RESUMO

BACKGROUND: In Italy, the law does not permit the setting up of private banks to preserve cord blood (CB) stem cells for personal use. However, since 2007 the right to export and preserve them in private laboratories located outside Italy has existed, and an increasing number of women are requesting this collection of umbilical CB at delivery to enable storage of stem cells for autologous use. STUDY DESIGN AND METHODS: Since private banks recruit clients mainly via the Internet, we examined the content of 24 Italian-language websites that offer stem cells storage (from CB or amniotic fluid), to assess what information is available. RESULTS: We found that the majority of private banks give no clear information about the procedures of collection, processing, and banking of CB units and that the standards offered by private CB banks strongly differ in terms of exclusion or acceptance criteria from the public banks. These factors may well influence the overall quality of the CB units stored in private CB banks. Of note, during the period 2007 to 2009, the number collected for autologous use did not create a downward trend on the number of units stored in public CB banks for allogeneic use. CONCLUSION: CB is a valuable community resource but expectant parents should be better informed as to the quality variables necessary for its storage, both by institutions and by professionals. Currently, most of the advertising is insufficient to justify the expense and the hopes pinned on autologous use of CB stem cells.


Assuntos
Bancos de Sangue/estatística & dados numéricos , Sangue Fetal , Criopreservação , Humanos , Itália
17.
Ann Ist Super Sanita ; 47(1): 72-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21430343

RESUMO

Fostering translational research of advanced therapies has become a major priority of both scientific community and national governments. Advanced therapy medicinal products (ATMP) are a new medicinal product category comprising gene therapy and cell-based medicinal products as well as tissue engineered medicinal products. ATMP development opens novel avenues for therapeutic approaches in numerous diseases, including cancer and neurodegenerative and cardiovascular diseases. However, there are important bottlenecks for their development due to the complexity of the regulatory framework, the high costs and the needs for good manufacturing practice (GMP) facilities and new end-points for clinical experimentation. Thus, a strategic cooperation between different stakeholders (academia, industry and experts in regulatory issues) is strongly needed. Recently, a great importance has been given to research infrastructures dedicated to foster translational medicine of advanced therapies. Some ongoing European initiatives in this field are presented and their potential impact is discussed.


Assuntos
Pesquisa Translacional Biomédica/tendências , Terapia Baseada em Transplante de Células e Tecidos , Tratamento Farmacológico , Terapia Genética , Humanos , Engenharia Tecidual , Pesquisa Translacional Biomédica/organização & administração
18.
Acta Neurochir Suppl ; 108: 103-5, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21107944

RESUMO

BACKGROUND: Degeneration of the intervertebral disc can be the source of severe low back pain. Intradiscal electrothermal therapy (IDET) is a minimally invasive treatment option for patients with symptomatic internal disc disruption nonresponsive to conservative medical care. METHODS: Using MRI and discographic findings, 50 patients with lumbar discogenic pain were identified, underwent IDET treatment and were followed for 24 months. Outcomes included assessments of back pain severity by an 11-point numeric scale and back function by the Oswestry disability index (ODI). FINDINGS: There was an average 68 and 66% improvement in pain and ODI, respectively, between pre-treatment and 24 months (p < 0.0001 for both comparisons). The global clinical success rate was 78% (39 of 50). Clinical success was associated with discographic concordance (p < 0.0001), HIZ (p = 0.003), Pfirrmann grade (p = 0.0002), and percent annulus coverage (p < 0.0001). CONCLUSIONS: The findings of this study suggest that durable clinical improvements can be realized after IDET in highly selected patients with mild disc degeneration, confirmatory imaging evidence of annular disruption and concordant pain provocation by low pressure discography.


Assuntos
Terapia por Estimulação Elétrica/métodos , Hipertermia Induzida/métodos , Dor Lombar/terapia , Seguimentos , Humanos , Deslocamento do Disco Intervertebral/complicações , Dor Lombar/etiologia , Imageamento por Ressonância Magnética , Medição da Dor , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento
19.
J Med Chem ; 54(1): 289-301, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21141896

RESUMO

Infections caused by hepatitis C virus (HCV) are a significant world health problem for which novel therapies are in urgent demand. The polymerase of HCV is responsible for the replication of viral genome and has been a prime target for drug discovery efforts. Here, we report on the further development of tetracyclic indole inhibitors, binding to an allosteric site on the thumb domain. Structure-activity relationship (SAR) studies around an indolo-benzoxazocine scaffold led to the identification of compound 33 (MK-3281), an inhibitor with good potency in the HCV subgenomic replication assay and attractive molecular properties suitable for a clinical candidate. The compound caused a consistent decrease in viremia in vivo using the chimeric mouse model of HCV infection.


Assuntos
Antivirais/síntese química , Hepacivirus/efeitos dos fármacos , Indóis/síntese química , Oxazocinas/síntese química , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Disponibilidade Biológica , Linhagem Celular Tumoral , Cristalografia por Raios X , Cães , Hepacivirus/enzimologia , Hepacivirus/fisiologia , Humanos , Indóis/farmacocinética , Indóis/farmacologia , Macaca mulatta , Camundongos , Camundongos SCID , Camundongos Transgênicos , Modelos Moleculares , Estrutura Molecular , Oxazocinas/farmacocinética , Oxazocinas/farmacologia , Ratos , Ratos Sprague-Dawley , Estereoisomerismo , Relação Estrutura-Atividade , Viremia/tratamento farmacológico , Viremia/virologia , Replicação Viral/efeitos dos fármacos
20.
Exp Hematol ; 38(6): 489-503.e1, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20303380

RESUMO

OBJECTIVES: To identify the regulatory sequences driving Gata1 expression in conventional dendritic cells (cDC). MATERIALS AND METHODS: The number and expression levels of Gata1, Gata1-target genes and hypersensitive site (HS) 2 (the eosinophil-specific enhancer)-driven green fluorescent protein (GFP) reporter of cDCs from mice lacking HS1 (the erythroid/megakaryocytic-specific enhancer, Gata1(low) mutation) and wild-type littermates, as well as the response to lipopolysaccharide of ex vivo-generated wild-type and Gata1(low) DCs were investigated. RESULTS: cDC maturation was associated with bell-shaped changes in Gata1 expression that peaked in cDCs precursors from blood. The Gata1(low) mutation did not affect Gata1 expression in cDC precursors and these cells expressed the HS2-driven reporter, indicating that Gata1 expression is HS2-driven in these cells. By contrast, the Gata1(low) mutation reduced Gata1 expression in mature cDCs and these cells did not express GFP, indicating that mature cDCs express Gata1 driven by HS1. In blood, the number of cDC precursors expressing CD40/CD80 was reduced in Gata1(low) mice, while CD40(pos)/CD80(pos) cDC precursors from wild-type mice expressed the HS2-GFP reporter, suggesting that Gata1 expression in these cells is both HS1- and HS2-driven. In addition, the antigen and accessory molecules presentation process induced by lipopolysaccharide in ex vivo-generated wild-type DC was associated with increased acetylated histone 4 occupancy of HS1, while ex vivo-generated Gata1(low) cDCs failed to respond to lipopolysaccharide, suggesting that HS1 activation is required for cDC maturation. CONCLUSION: These results identify a dynamic pattern of Gata1 regulation that switches from an HS1 to an HS2-dependent phase during the maturation of cDCs associated with the antigen-presentation process in the blood.


Assuntos
Células Dendríticas/metabolismo , Fator de Transcrição GATA1/genética , Animais , Antígenos CD/imunologia , Sequência de Bases , Cromatina/genética , Imunoprecipitação da Cromatina , Primers do DNA , Células Dendríticas/citologia , Células Dendríticas/imunologia , Feminino , Citometria de Fluxo , Genes Reporter , Proteínas de Fluorescência Verde/genética , Interleucina-4/metabolismo , Masculino , Camundongos , Mutação , Reação em Cadeia da Polimerase Via Transcriptase Reversa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...