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1.
Clin Exp Immunol ; 176(3): 394-400, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24611904

RESUMO

X-linked inhibitor of apoptosis (XIAP) deficiency, caused by mutations in BIRC4, is an immunodeficiency associated with immune dysregulation and a highly variable clinical presentation. Current diagnostic screening tests such as flow cytometry for XIAP expression or lymphocyte apoptosis assays have significant limitations. Based on recent evidence that XIAP is essential for nucleotide-binding and oligomerization domains (NOD)1/2 signalling, we evaluated the use of a simple flow cytometric assay assessing tumour necrosis factor (TNF) production of monocytes in response to NOD2 stimulation by muramyl dipeptides (L18-MDP) for the functional diagnosis of XIAP deficiency. We investigated 12 patients with XIAP deficiency, six female carriers and relevant disease controls. Irrespective of the diverse clinical phenotype, the extent of residual protein expression or the nature of the mutation, the TNF response was severely reduced in all patients. On average, L18-MDP induced TNF production in 25% of monocytes from healthy donors or female carriers, while fewer than 6% of monocytes responded in affected patients. Notably, the assay clearly discriminated affected patients from disease controls with other immunodeficiencies accompanied by lymphoproliferation, hypogammaglobulinaemia or inflammatory bowel disease. Functional testing of the NOD2 signalling pathway is an easy, fast and reliable assay in the diagnostic evaluation of patients with suspected XIAP deficiency.


Assuntos
Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/deficiência , Acetilmuramil-Alanil-Isoglutamina/análogos & derivados , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Lactente , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Mutação , Proteína Adaptadora de Sinalização NOD2/metabolismo , Fenótipo , Linfócitos T/metabolismo , Fatores de Necrose Tumoral/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Adulto Jovem
2.
Clin Immunol ; 149(1): 133-41, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23973892

RESUMO

X-linked inhibitor of apoptosis (XIAP) deficiency caused by mutations in BIRC4 was initially described in patients with X-linked lymphoproliferative syndrome (XLP) who had no mutations in SH2D1A. In the initial reports, EBV-associated hemophagocytic lymphohistiocytosis (HLH) was the predominant clinical phenotype. Among 25 symptomatic patients diagnosed with XIAP deficiency, we identified 17 patients who initially presented with manifestations other than HLH. These included Crohn-like bowel disease (n=6), severe infectious mononucleosis (n=4), isolated splenomegaly (n=3), uveitis (n=1), periodic fever (n=1), fistulating skin abscesses (n=1) and severe Giardia enteritis (n=1). Subsequent manifestations included celiac-like disease, antibody deficiency, splenomegaly and partial HLH. Screening by flow cytometry identified 14 of 17 patients in our cohort. However, neither genotype nor protein expression nor results from cell death studies were clearly associated with the clinical phenotype. Only mutation analysis can reliably identify affected patients. XIAP deficiency must be considered in a wide range of clinical presentations.


Assuntos
Síndromes de Imunodeficiência/genética , Linfo-Histiocitose Hemofagocítica/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/deficiência , Adolescente , Adulto , Criança , Pré-Escolar , Genótipo , Humanos , Síndromes de Imunodeficiência/imunologia , Linfo-Histiocitose Hemofagocítica/imunologia , Masculino , Mutação , Células T Matadoras Naturais/imunologia , Fenótipo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/imunologia , Adulto Jovem
3.
Cell Death Differ ; 11(3): 301-13, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14685158

RESUMO

Recent studies strongly suggest an active involvement of the c-Jun N-terminal kinase (JNK) signaling pathway in tumor necrosis factor (TNF)-induced apoptosis. The direct evidence for the role of JNK and its isoforms has been missing and the mechanism of how JNK actually could facilitate this process has remained unclear. In this study, we show that Jnk2-/- primary mouse embryonic fibroblasts (pMEFs) exhibit resistance towards TNF-induced apoptosis as compared to corresponding wild-type and Jnk1-/- pMEFs. JNK2-deficient pMEFs could be resensitized to TNF via retroviral transduction of any of the four different JNK2 splicing variants. Jnk2-/- pMEFs displayed deficient and delayed effector caspase activation as well as impaired cytosolic cystein cathepsin activity: processes that both were needed for efficient TNF-induced apoptosis in pMEFs. Our work demonstrates that JNK has a central role in the promotion of TNF-induced apoptosis in pMEFs, and that the JNK2 isoform can regulate both mitochondrial and lysosomal death pathways in these cells.


Assuntos
Apoptose/efeitos dos fármacos , Caspases/metabolismo , Catepsinas/metabolismo , Fibroblastos/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Processamento Alternativo , Animais , Caspases/análise , Catepsina B/metabolismo , Catepsinas/análise , Sobrevivência Celular , Citocromos c/metabolismo , Citosol/enzimologia , DNA/metabolismo , Ativação Enzimática/efeitos dos fármacos , Feto/citologia , Feto/metabolismo , Fibroblastos/citologia , Deleção de Genes , Variação Genética , Lisossomos/metabolismo , Camundongos , Microscopia Confocal , Mitocôndrias/metabolismo , Modelos Biológicos , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-jun/deficiência , Proteínas Proto-Oncogênicas c-jun/genética , Retroviridae/genética , Coloração e Rotulagem
4.
Acta Physiol Scand ; 171(3): 349-58, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11412148

RESUMO

Duchenne's muscular dystrophy (DMD) is a fatal disease caused by mutations in the DMD gene that lead to quantitative and qualitative disturbances in dystrophin expression. Dystrophin is a member of the spectrin superfamily of proteins. Dystrophin itself is closely related to three proteins that constitute a family of dystrophin-related proteins (DRPs): the chromosome 6-encoded DRP or utrophin, the chromosome-X encoded, DRP2 and the chromosome-18 encoded, dystrobrevin. These proteins share sequence similarity and functional motifs with dystrophin. Current attempts at somatic gene therapy of DMD face numerous technical problems. An alternative strategy for DMD therapy, that circumvents many of these problems, has arisen from the demonstration that the DRP utrophin can functionally substitute for the missing dystrophin and its overexpression can rescue dystrophin-deficient muscle. Currently, a promising avenue of research consists of identifying molecules that would increase the expression of utrophin and the delivery of these molecules to dystrophin-deficient tissues as a means of DMD therapy. In this review, we will focus on DRPs from the perspective of strategies and issues related to upregulating utrophin expression for DMD therapy. Additionally, we will address the techniques used for anatomical, biochemical and physiological evaluation of the potential benefits of this and other forms of DMD therapy in dystrophin-deficient animal models.


Assuntos
Distrofina/genética , Terapia Genética , Distrofia Muscular de Duchenne/terapia , Animais , Gatos , Proteínas do Citoesqueleto/biossíntese , Proteínas do Citoesqueleto/genética , Modelos Animais de Doenças , Cães , Humanos , Proteínas de Membrana/biossíntese , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Distrofia Muscular Animal/genética , Distrofia Muscular Animal/terapia , Distrofia Muscular de Duchenne/genética , Regulação para Cima , Utrofina
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