Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Toxicol Pathol ; 46(7): 735-745, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30139307

RESUMO

Short interfering RNAs (siRNAs) and antisense oligonucleotides (ASOs) are the most clinically advanced oligonucleotide-based platforms. A number of N-acetylgalactosamine (GalNAc)-conjugated siRNAs (GalNAc-siRNAs), also referred to as RNA interference (RNAi) therapeutics, are currently in various stages of development, though none is yet approved. While the safety of ASOs has been the subject of extensive review, the nonclinical safety profiles of GalNAc-siRNAs have not been reported. With the exception of sequence differences that confer target RNA specificity, GalNAc-siRNAs are largely chemically uniform, containing limited number of phosphorothioate linkages, and 2'-O-methyl and 2'-deoxy-2'-fluoro ribose modifications. Here, we present the outcomes of short-term (3-5 week) rat and monkey weekly repeat-dose toxicology studies of six Enhanced Stabilization Chemistry GalNAc-siRNAs currently in clinical development. In nonclinical studies at supratherapeutic doses, these molecules share similar safety signals, with histologic findings in the organ of pharmacodynamic effect (liver), the organ of elimination (kidney), and the reticuloendothelial system (lymph nodes). The majority of these changes are nonadverse, partially to completely reversible, correlate well with pharmacokinetic parameters and tissue distribution, and often reflect drug accumulation. Furthermore, all GalNAc-siRNAs tested to date have been negative in genotoxicity and safety pharmacology studies.


Assuntos
Acetilgalactosamina/toxicidade , Aberrações Cromossômicas/induzido quimicamente , Fígado/efeitos dos fármacos , RNA Interferente Pequeno/toxicidade , Acetilgalactosamina/química , Acetilgalactosamina/farmacologia , Animais , Células CHO , Cricetulus , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Fígado/patologia , Linfócitos/efeitos dos fármacos , Linfócitos/patologia , Macaca fascicularis , Testes de Mutagenicidade , RNA Interferente Pequeno/química , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Ratos Sprague-Dawley , Especificidade da Espécie , Testes de Toxicidade Subaguda
2.
J Exp Med ; 202(6): 841-51, 2005 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-16172261

RESUMO

Experimental autoimmune encephalomyelitis (EAE), a Th1-mediated inflammatory disease of the central nervous system (CNS), is a model of human multiple sclerosis. Cytosolic phospholipase A2alpha (cPLA2alpha), which initiates production of prostaglandins, leukotrienes, and platelet-activating factor, is present in EAE lesions. Using myelin oligodendrocyte glycoprotein (MOG) immunization, as well as an adoptive transfer model, we showed that cPLA2alpha-/- mice are resistant to EAE. Histologic examination of the CNS from MOG-immunized mice revealed extensive inflammatory lesions in the cPLA2alpha+/- mice, whereas the lesions in cPLA2alpha-/- mice were reduced greatly or completely absent. MOG-specific T cells generated from WT mice induced less severe EAE in cPLA2alpha-/- mice compared with cPLA2alpha+/- mice, which indicates that cPLA2alpha plays a role in the effector phase of EAE. Additionally, MOG-specific T cells from cPLA2alpha-/- mice, transferred into WT mice, induced EAE with delayed onset and lower severity compared with EAE that was induced by control cells; this indicates that cPLA2alpha also plays a role in the induction phase of EAE. MOG-specific T cells from cPLA2alpha-/- mice were deficient in production of Th1-type cytokines. Consistent with this deficiency, in vivo administration of IL-12 rendered cPLA2alpha-/- mice susceptible to EAE. Our data indicate that cPLA2alpha plays an important role in EAE development and facilitates differentiation of T cells toward the Th1 phenotype.


Assuntos
Diferenciação Celular/imunologia , Citosol/enzimologia , Encefalomielite Autoimune Experimental/enzimologia , Encefalomielite Autoimune Experimental/genética , Fosfolipases A/deficiência , Células Th1/imunologia , Animais , Encefalomielite Autoimune Experimental/imunologia , Feminino , Fosfolipases A2 do Grupo IV , Imunidade Inata/genética , Imunofenotipagem , Interleucina-12/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas da Mielina , Glicoproteína Associada a Mielina/imunologia , Glicoproteína Mielina-Oligodendrócito , Fosfolipases A/genética , Fosfolipases A/metabolismo , Fosfolipases A2 , Medula Espinal/imunologia , Medula Espinal/patologia , Células Th1/citologia
3.
Nature ; 434(7033): 644-8, 2005 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-15800624

RESUMO

Human osteoarthritis is a progressive disease of the joints characterized by degradation of articular cartilage. Although disease initiation may be multifactorial, the cartilage destruction appears to be a result of uncontrolled proteolytic extracellular matrix destruction. A major component of the cartilage extracellular matrix is aggrecan, a proteoglycan that imparts compressive resistance to the tissue. Aggrecan is cleaved at a specific 'aggrecanase' site in human osteoarthritic cartilage; this cleavage can be performed by several members of ADAMTS family of metalloproteases. The relative contribution of individual ADAMTS proteases to cartilage destruction during osteoarthritis has not been resolved. Here we describe experiments with a genetically modified mouse in which the catalytic domain of ADAMTS5 (aggrecanase-2) was deleted. After surgically induced joint instability, there was significant reduction in the severity of cartilage destruction in the ADAMTS5 knockout mice compared with wild-type mice. This is the first report of a single gene deletion capable of abrogating the course of cartilage destruction in an animal model of osteoarthritis. These results demonstrate that ADAMTS5 is the primary 'aggrecanase' responsible for aggrecan degradation in a murine model of osteoarthritis, and suggest rational strategies for therapeutic intervention in osteoarthritis.


Assuntos
Cartilagem Articular/metabolismo , Modelos Animais de Doenças , Deleção de Genes , Metaloendopeptidases/deficiência , Metaloendopeptidases/genética , Osteoartrite/metabolismo , Proteínas ADAM , Proteína ADAMTS5 , Animais , Domínio Catalítico , Endopeptidases/química , Endopeptidases/deficiência , Endopeptidases/genética , Endopeptidases/metabolismo , Éxons/genética , Cabeça do Fêmur , Lâmina de Crescimento/metabolismo , Articulações/patologia , Articulações/fisiopatologia , Metaloendopeptidases/química , Metaloendopeptidases/metabolismo , Camundongos , Camundongos Knockout , Osteoartrite/genética , Osteoartrite/patologia , Osteoartrite/fisiopatologia , Proteoglicanas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
4.
Rheumatology (Oxford) ; 48(11): 1352-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19713442

RESUMO

OBJECTIVES: To investigate the expression and function of triggering receptor expressed on myeloid cells-1 (TREM-1) in the synovium of human RA patients as well as the level of soluble TREM-1 in the plasma of RA patients. METHODS: Twenty-four RA synovial samples were analysed by gene expression oligonucleotide microarrays. Expression levels of TREM-1 mRNA in murine CIA paws were determined by quantitative PCR (qPCR). TREM-1 protein expression was detected by immunohistochemistry in five RA synovial samples and two OA synovial samples. TREM-1-positive cells from five RA synovial tissues were analysed by FACS staining to determine the cell type. Activation of TREM-1 was tested in five RA synovial samples. Soluble TREM-1 was measured in serum from 32 RA patients. RESULTS: The expression of TREM-1 mRNA was found to increase 6.5-fold in RA synovial samples, whereas it was increased 132-fold in CIA paws. Increased numbers of TREM-1-positive cells were seen in RA synovium sections and these cells co-expressed CD14. Using a TREM-1-activating cross-linking antibody in RA synovial cultures, multiple pro-inflammatory cytokines were induced. The average amount of soluble TREM-1 in plasma from RA patients was found to be higher than that in plasma from healthy volunteers. CONCLUSIONS: These findings suggest that the presence of high levels of functionally active TREM-1 in RA synovium may contribute to the development or maintenance of RA, or both. Inhibiting TREM-1 activity may, therefore, have a therapeutic effect on RA. High levels of soluble TREM-1 in the plasma of RA patients compared with healthy volunteers may indicate disease activity.


Assuntos
Artrite Reumatoide/imunologia , Citocinas/biossíntese , Glicoproteínas de Membrana/metabolismo , Receptores Imunológicos/metabolismo , Membrana Sinovial/imunologia , Animais , Artrite Experimental/imunologia , Biomarcadores/metabolismo , Células Cultivadas , Expressão Gênica , Perfilação da Expressão Gênica/métodos , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos DBA , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/genética , Receptores Imunológicos/sangue , Receptores Imunológicos/genética , Receptor Gatilho 1 Expresso em Células Mieloides
5.
J Neuroimmunol ; 182(1-2): 124-34, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17182110

RESUMO

Interactions between PD-1 and its two differentially expressed ligands, PD-L1 and PD-L2, attenuate T cell activation and effector function. To determine the role of these molecules in autoimmune disease of the CNS, PD-1-/-, PD-L1-/- and PD-L2-/- mice were generated and immunized to induce experimental autoimmune encephalomyelitis (EAE). PD-1-/- and PD-L1-/- mice developed more severe EAE than wild type and PD-L2-/- mice. Consistent with this, PD-1-/- and PD-L1-/- cells produced elevated levels of the pro-inflammatory cytokines IFN-gamma, TNF, IL-6 and IL-17. These results demonstrate that interactions between PD-1/PD-L1, but not PD-1/PDL-2, are crucial in attenuating T cell responses in EAE.


Assuntos
Antígenos de Diferenciação/metabolismo , Antígeno B7-1/metabolismo , Encefalomielite Autoimune Experimental/fisiopatologia , Glicoproteínas de Membrana/metabolismo , Peptídeos/metabolismo , Animais , Antígeno B7-H1 , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/metabolismo , Encefalomielite Autoimune Experimental/patologia , Glicoproteínas/imunologia , Humanos , Interferon gama/biossíntese , Interleucina-17/biossíntese , Interleucina-6/biossíntese , Linfonodos/metabolismo , Linfonodos/patologia , Ativação Linfocitária , Glicoproteínas de Membrana/deficiência , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Glicoproteína Mielina-Oligodendrócito , Fragmentos de Peptídeos/imunologia , Peptídeos/deficiência , Proteína 2 Ligante de Morte Celular Programada 1 , Receptor de Morte Celular Programada 1 , Índice de Gravidade de Doença , Linfócitos T/imunologia , Fator de Necrose Tumoral alfa/biossíntese
6.
Arthritis Rheum ; 50(8): 2547-58, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15334469

RESUMO

OBJECTIVE: To determine the importance of the enzymatic activity of ADAMTS-4 in normal growth and development and to evaluate the role of ADAMTS-4 in the progression of osteoarthritis (OA). METHODS: We generated catalytic domain-deleted ADAMTS-4-transgenic mice and performed extensive gross and histologic analyses of various organs. The mice were challenged by surgical induction of joint instability leading to OA, to determine the importance of the enzymatic activity of ADAMTS-4 in the progression of the disease. The response of wild-type (WT) and ADAMTS-4-knockout (ADAMTS-4-KO) articular cartilage to interleukin-1 and retinoic acid challenge in vitro was also evaluated. RESULTS: ADAMTS-4-KO mice up to 1 year of age exhibited no gross or histologic abnormalities in 36 tissue sites examined. Despite evidence of ADAMTS-4 expression and activity in growth plates of WT mice, catalytic silencing of this proteinase caused no abnormalities in skeletal development, growth, or remodeling. There was no effect of ADAMTS-4 knockout on the progression or severity of OA 4 weeks or 8 weeks after surgical induction of joint instability. Enzymatic cleavage of aggrecan at the TEGE(373-374)ARGS site was clearly evident after exposure of articular cartilage from ADAMTS-4-KO mice to inflammatory cytokines. CONCLUSION: Although expression of the ADAMTS-4 gene has been found in many tissues throughout the body, deletion of enzymatic activity did not appear to have any effect on normal growth and physiology. Our study provides evidence that ADAMTS-4 is the primary aggrecanase in murine growth plates; however, deletion of its enzymatic activity did not affect normal long bone remodeling. Our results also lead to the hypothesis that, in the mouse, ADAMTS-4 is not the primary enzyme responsible for aggrecan degradation at the TEGE(373-374)ARGS site. The elucidation of the relative importance of ADAMTS-4 in the pathologic process of human OA will require examination of human OA tissues and evidence of disease modification in patients following therapeutic intervention.


Assuntos
Metaloendopeptidases/fisiologia , Osteoartrite/etiologia , Proteínas ADAM , Proteína ADAMTS4 , Agrecanas , Animais , Cartilagem Articular/efeitos dos fármacos , Progressão da Doença , Proteínas da Matriz Extracelular/metabolismo , Interleucina-1/farmacologia , Lectinas Tipo C , Metaloendopeptidases/genética , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Osteoartrite/enzimologia , Pró-Colágeno N-Endopeptidase , Proteoglicanas/metabolismo , Tretinoína/farmacologia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa