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1.
Br J Dermatol ; 185(6): 1221-1231, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34105768

RESUMO

BACKGROUND: Frontal fibrosing alopecia (FFA) has become one of the most common causes of cicatricial alopecia worldwide. However, there is a lack of clear aetiology and robust clinical trial evidence for the efficacy and safety of agents currently used for treatment. OBJECTIVES: To enable data to be collected worldwide on FFA using common criteria and assessment methods. METHODS: A multicentre, international group of experts in hair loss was convened by email to create consensus recommendations for clinical trials. Consensus was defined at > 90% agreement on each recommended part of these guidelines. RESULTS: Standardized diagnostic criteria, severity rating, staging, and investigator and patient assessment of scalp hair loss and other clinical features of FFA were created. CONCLUSIONS: These guidelines should allow the collection of reliable aggregate data on FFA and advance efforts in both clinical and basic research to close knowledge gaps in this condition.


Assuntos
Alopecia , Ensaios Clínicos como Assunto , Guias como Assunto , Líquen Plano , Alopecia/tratamento farmacológico , Cicatriz/tratamento farmacológico , Cicatriz/etiologia , Consenso , Humanos , Líquen Plano/patologia , Couro Cabeludo/patologia
2.
Exp Dermatol ; 22(9): 609-26, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23947678

RESUMO

The pathobiology of alopecia areata (AA), one of the most frequent autoimmune diseases and a major unsolved clinical problem, has intrigued dermatologists, hair biologists and immunologists for decades. Simultaneously, both affected patients and the physicians who take care of them are increasingly frustrated that there is still no fully satisfactory treatment. Much of this frustration results from the fact that the pathobiology of AA remains unclear, and no single AA pathogenesis concept can claim to be universally accepted. In fact, some investigators still harbour doubts whether this even is an autoimmune disease, and the relative importance of CD8(+) T cells, CD4(+) T cells and NKGD2(+) NK or NKT cells and the exact role of genetic factors in AA pathogenesis remain bones of contention. Also, is AA one disease, a spectrum of distinct disease entities or only a response pattern of normal hair follicles to immunologically mediated damage? During the past decade, substantial progress has been made in basic AA-related research, in the development of new models for translationally relevant AA research and in the identification of new therapeutic agents and targets for future AA management. This calls for a re-evaluation and public debate of currently prevalent AA pathobiology concepts. The present Controversies feature takes on this challenge, hoping to attract more skin biologists, immunologists and professional autoimmunity experts to this biologically fascinating and clinically important model disease.


Assuntos
Alopecia em Áreas/etiologia , Doenças Autoimunes/etiologia , Alopecia em Áreas/imunologia , Alopecia em Áreas/patologia , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Modelos Animais de Doenças , Humanos , Camundongos , Modelos Imunológicos , Pesquisa Translacional Biomédica
3.
Br J Dermatol ; 168(4): 771-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23106683

RESUMO

BACKGROUND: Neuroimmunological disorders are involved in the pathogenesis of atopic dermatitis (AD), partly through enhanced sensory nerve-skin mast cell interaction. Cell adhesion molecule 1 (CADM1) is a mast-cell adhesion molecule that mediates the adhesion to, and communication with, sympathetic nerves. OBJECTIVES: To investigate the role of mast cell CADM1 in the pathogenesis of AD, CADM1 expression levels by comparing between lesional and nonlesional skin mast cells of an AD mouse model, which was developed by repeated application of trinitrochlorobenzene, and to examine, in cocultures, how the alterations in CADM1 detected in lesional mast cells might affect the sensory nerve-mast cell interaction. METHODS: AD-like lesional and nonlesional skin mast cells were collected separately by laser capture microdissection. CADM1 expression was examined by reverse transcription-polymerase chain reaction and CADM1 immunohistochemistry. In cocultures, adhesion between dorsal root ganglion (DRG) neurites and IC2 mast cells was analysed by loading a femtosecond laser-induced impulsive force on neurite-attendant IC2 cells, while cellular communication was monitored as the IC2 cellular response ([Ca(2+)]i increase) after nerve-specific stimulant-induced DRG activation. RESULTS: AD-like lesional mast cells expressed three-fold more CADM1 transcripts than nonlesional cells. This was supported at the protein level, shown by immunohistochemistry. In coculture, CADM1 overexpression in IC2 cells strengthened DRG neurite-IC2 cell adhesion and doubled the population of IC2 cells responding to DRG activation. A function-blocking anti-CADM1 antibody abolished these effects in a dose-dependent manner. CONCLUSIONS: Increased expression of CADM1 in mast cells appeared to be a cause of enhanced sensory nerve-mast cell interaction in a hapten-induced mouse model of AD.


Assuntos
Moléculas de Adesão Celular/metabolismo , Dermatite Atópica/metabolismo , Imunoglobulinas/metabolismo , Mastócitos/metabolismo , Células Receptoras Sensoriais/fisiologia , Animais , Adesão Celular , Molécula 1 de Adesão Celular , Moléculas de Adesão Celular/fisiologia , Comunicação Celular/fisiologia , Células Cultivadas , Dermatite Atópica/induzido quimicamente , Pavilhão Auricular , Gânglios Espinais/fisiologia , Haptenos/toxicidade , Imunoglobulinas/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Neuritos/fisiologia , Cloreto de Picrila/toxicidade , Venenos de Escorpião/farmacologia
4.
Clin Exp Dermatol ; 35(4): 361-5, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19874321

RESUMO

BACKGROUND: We have previously reported several trichoscopic (dermatoscopic) characteristics, such as black dots, 'exclamation-mark' hairs, broken hairs, yellow dots and clustered short vellus hairs as being useful clinical indicators for alopecia areata (AA). 'Coudability hairs', which are normal-looking hairs tapered at the proximal end, have been previously reported as another sign of AA. AIMS: To use trichoscopy to evaluate coudability hairs as a clinical indicator for the disease activity of AA and a substitute-marker for the hair-pull test. METHODS: Trichoscopic examinations of hair loss and perilesional areas on the scalps of 100 East Asian patients with AA were performed using a dermatoscope. Using Spearman's rank-order correlation coefficient by rank test, we examined the correlations of scores between coudability and AA disease activity, severity or duration and other trichoscopic features, and then evaluated the coudability score as a surrogate-marker for the hair-pull test. RESULTS: Coudability scores correlated positively with AA disease activity, hair-pull tests, short duration, black dots and exclamation-mark hairs, and correlated negatively with short vellus hairs. CONCLUSIONS: Coudability hairs, more closely perceived by trichoscopy, are useful-markers for disease activity in AA and provide a surrogate-marker for the hair-pull test.


Assuntos
Alopecia em Áreas/diagnóstico , Cabelo/patologia , Adolescente , Adulto , Idoso , Alopecia em Áreas/patologia , Criança , Pré-Escolar , Dermoscopia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Fatores de Tempo , Adulto Jovem
5.
Oncogene ; 26(33): 4882-8, 2007 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-17297448

RESUMO

Various common signaling pathways maintain tissue stem cells, including Notch and Wnt/beta-catenin signals. Phosphoinositide-3 kinase (PI3K)/Akt signaling regulates the 'stemness' of several stem cells in culture, specifically in maintaining embryonic stem and neural stem cells, and in deriving embryonic germ cells from primordial germ cells. We examined the effect of Akt signaling in epidermal cells in transgenic mice expressing an Akt-Mer fusion protein whose kinase activity was conditionally activated by treatment with 4-hydroxytamoxifen (4OHT). The topical application of 4OHT to adult skin of the transgenic mice induced new hair growth in resting phase follicles. In addition, the mice showed hyperplasia in interfollicular epidermis (IFE) and hair follicles, which was presumably caused by the extensive proliferation of keratinocytes in basal layer of IFE and outer root sheath of hair follicles, respectively. The progenitor cell population increased consistently in 4OHT-treated transgenic mice. Our results show that PI3K/Akt signaling induces epidermal hyperplasia and proliferation of epidermal progenitors.


Assuntos
Proliferação de Células/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células-Tronco/efeitos dos fármacos , Tamoxifeno/análogos & derivados , Animais , Animais Recém-Nascidos , Antígenos CD34/análise , Sítios de Ligação/genética , Ativação Enzimática/efeitos dos fármacos , Epiderme/metabolismo , Epiderme/patologia , Etanol/farmacologia , Citometria de Fluxo , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/metabolismo , Folículo Piloso/patologia , Hiperplasia , Integrina alfa6/análise , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/patologia , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-akt/genética , Receptores de Estrogênio/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Pele/patologia , Células-Tronco/metabolismo , Células-Tronco/patologia , Tamoxifeno/farmacologia
7.
Br J Dermatol ; 152(4): 616-22, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15840089

RESUMO

BACKGROUND: The usefulness of bone marrow cells in accelerating wound healing has not been evaluated despite increasing evidence that bone marrow contains mesenchymal stem cells that have multipotentiality to differentiate into various types of cells after they enter the microenvironment of a specific tissue (niche). OBJECTIVES: To determine the effects of bone marrow cells and occlusive dressings in promoting wound healing in rats. METHODS: We investigated by grafting, biopsy and immunohistochemistry whether various types of cells derived from green fluorescent protein (GFP)-transgenic rats would differentiate into wound component cells when administered topically on the wounds of rats. We also investigated whether topical application of bone marrow cells with an occlusive dressing would accelerate the healing of wounds with exposed bones, as measured by planimetry. RESULTS: GFP-labelled bone marrow cells contained multipotent stem cells that sufficiently differentiated into wound myofibroblasts presenting with alpha-smooth muscle actin in granulation tissue. Other types of cells, including myocytes, adipocytes, peripheral blood cells from buffy coat and dermal fibroblasts, did not express myofibroblast characteristics morphologically or immunohistochemically. Application of bone marrow cells and an occlusive dressing accelerated the repair of wounds with exposed bones, compared with an occlusive dressing only or with the topical administration of bone marrow cells plus a semidry to dry dressing. CONCLUSIONS: Our study indicates that bone marrow cells accelerate the healing of wounds at least in part through their differentiation into wound myofibroblasts. Thus, treatment of wounds with bone marrow cells and a supportive occlusive dressing is effective in promoting the formation of healthy granulation tissue and also for the preparation of an ideal wound bed.


Assuntos
Células da Medula Óssea/fisiologia , Curativos Oclusivos , Cicatrização/fisiologia , Animais , Animais Geneticamente Modificados , Transplante de Medula Óssea/métodos , Diferenciação Celular/fisiologia , Transplante de Células/métodos , Fibroblastos/fisiologia , Imuno-Histoquímica/métodos , Músculo Liso/lesões , Músculo Liso/patologia , Ratos , Ratos Wistar
8.
Br J Dermatol ; 152(4): 664-72, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15840096

RESUMO

BACKGROUND: Wounds with exposed bones caused by rheumatic diseases commonly result in amputation despite progress in our understanding of wound-healing mechanisms. OBJECTIVES: To determine whether an experimental therapy of bone marrow exposure, an occlusive dressing and subsequent grafting of epidermal sheets accelerates healing and reduces the need for amputation in patients with rheumatic diseases. METHODS: Fifteen patients, including those with rheumatoid arthritis or systemic sclerosis, who had wounds with exposed bones were treated either with the standard procedure, consisting of local wound care, debridement with a scalpel, bed rest and parenteral antibiotics (n = 8), or with a newly developed experimental procedure (n = 7). In that new procedure, the affected bone was initially exposed by debridement with a scalpel, followed by partial excision with a bone scraper until bleeding was observed from the exposed bone. The lesions were immediately covered with an occlusive dressing, and were eventually treated with epidermal grafts obtained from suction blisters. RESULTS: A comparison with standard therapy demonstrated that the time needed for wound healing was similar, but that the newly developed combination therapy reduced the risk of amputation (P = 0.020). No skin ulcers or erosions were observed for at least 1 year in five of seven patients (72%) due to the adoption of stable palmoplantar-type characteristics in grafts derived from the trunk epidermis. CONCLUSIONS: Our study indicates that exposure of bone marrow cells plus an occlusive dressing accelerates the healing of skin ulcers at least partly through the preparation of a healthy well-granulated wound bed and that subsequent epidermal grafting achieves site-specific differentiation through epithelial-mesenchymal interactions.


Assuntos
Amputação Cirúrgica , Medula Óssea/cirurgia , Epiderme/transplante , Curativos Oclusivos , Doenças Reumáticas/terapia , Cicatrização/fisiologia , Adulto , Idoso , Artrite Reumatoide/fisiopatologia , Artrite Reumatoide/cirurgia , Artrite Reumatoide/terapia , Medula Óssea/fisiopatologia , Células da Medula Óssea/fisiologia , Epiderme/fisiopatologia , Feminino , Dedos , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Reumáticas/fisiopatologia , Doenças Reumáticas/cirurgia , Escleroderma Sistêmico/fisiopatologia , Escleroderma Sistêmico/cirurgia , Escleroderma Sistêmico/terapia , Pele/fisiopatologia , Úlcera Cutânea/fisiopatologia , Úlcera Cutânea/cirurgia , Úlcera Cutânea/terapia , Fatores de Tempo , Dedos do Pé , Resultado do Tratamento
9.
Br J Dermatol ; 151(5): 1019-28, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15541080

RESUMO

BACKGROUND: Diabetic foot ulcers with exposed bones commonly result in amputation. OBJECTIVES: To determine whether exposure of bone marrow cells and subsequent grafting of epidermal sheets accelerates healing and reduces the need for amputation. METHODS: Thirty-eight patients with chronic wounds caused by diabetes mellitus were enrolled in this study. Epidermal sheets obtained from suction blisters of each patient were grafted on to diabetic foot ulcers without exposed bones (n = 10) and were compared with the standard treatment of local wound care, debridement with a scalpel when indicated, bed rest and parenteral antibiotics (n = 8). In another group of patients, diabetic wounds with exposed bones were treated either with the standard procedure (n = 9) or with a newly developed experimental procedure (n = 11). In that new procedure, the affected bone was initially exposed by debridement with a scalpel, followed by partial excision with a bone scraper until fresh bleeding was observed from the exposed bone. The lesions were then immediately covered with an occlusive dressing, and finally the wound was covered with an epidermal graft of skin harvested from suction blisters. Patients in each group were matched with their counterparts by age, sex, wound size, wound infection and wound duration, to compare the time needed for total skin repair and rates of amputation. RESULTS: Epidermal grafting significantly accelerated the healing of diabetic foot ulcers (P = 0.042) without exposed bones, with site-specific differentiation. The newly developed combination therapy resulted in the healing of all diabetic ulcers with exposed bones without the occurrence of osteomyelitis or the necessity for amputation (P < 0.0001). CONCLUSIONS: Our study indicates that early aggressive debridement of diabetic foot ulcers with exposed bones down to a bleeding vascularized base and then grafting epidermal sheets significantly improves healing and reduces the rate of amputation.


Assuntos
Células da Medula Óssea/fisiologia , Osso e Ossos/patologia , Pé Diabético/terapia , Epiderme/transplante , Cicatrização , Adulto , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Terapia Combinada , Desbridamento , Pé Diabético/complicações , Pé Diabético/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curativos Oclusivos , Osteomielite/complicações , Sucção
13.
Appl Microbiol Biotechnol ; 60(4): 442-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12466885

RESUMO

We constructed engineered CHO strains that can be used for high-level production of foreign proteins by gene-targeting. After transfecting dihydroforate reductase (DHFR)-deficient CHO cells with a plasmid carrying a loxP-green fluorescent protein (GFP) fusion gene and a DHFR gene, we screened colonies by fluorescent intensity. We selected 16 clones that expressed high levels of GFP and carried one copy of the plasmid in their chromosomes and treated them with methotrexate (MTX) to examine their ability for DHFR-mediated gene amplification. Two clones, MK1 and MK2, showed increased GFP expression upon gene amplification. In those clones, the loxP-GFP gene was integrated at a transcription-active, DHFR-mediated, gene-amplifiable locus in the chromosomes. A gene-targeting vector, carrying a loxP-fused hygromycin-resistance gene, was constructed to target desired genes in chromosomal loxP by Cre recombinase-mediated site-specific recombination. Using this cell-vector system, we could reproducibly obtain high producers of recombinant proteins by gene-targeting and gene amplification. In human monoclonal antibody production, after gene-targeting of loxP in MK2 and gene amplification with MTX, the MTX-resistant colonies showed high levels of antibody production. The most productive clone was able to produce 160 mg/l in 7 days in a low-protein medium in a spinner-flask.


Assuntos
Células CHO/fisiologia , Amplificação de Genes , Engenharia Genética/métodos , Plasmídeos/genética , Proteínas Recombinantes/biossíntese , Tetra-Hidrofolato Desidrogenase/biossíntese , Animais , Southern Blotting , Células CHO/enzimologia , Linhagem Celular , Cricetinae , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde , Humanos , Integrases , Proteínas Luminescentes/metabolismo , Plasmídeos/química , Tetra-Hidrofolato Desidrogenase/genética , Transfecção , Proteínas Virais
15.
Br J Plast Surg ; 55(5): 445-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12372380

RESUMO

We describe a giant basal cell carcinoma, measuring 40 cm x 20 cm, of the lower abdominal, genital and bilateral inguinal regions. The rectus abdominis muscle and the adductor magnus muscle were exposed centrally, and the penis and scrotum were completely destroyed. Reconstruction was performed with a fillet thigh flap, and an excellent result was obtained 1 year after surgery.


Assuntos
Parede Abdominal/patologia , Carcinoma Basocelular/patologia , Neoplasias dos Genitais Masculinos/patologia , Neoplasias Musculares/patologia , Parede Abdominal/cirurgia , Carcinoma Basocelular/cirurgia , Neoplasias dos Genitais Masculinos/cirurgia , Virilha , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Musculares/cirurgia , Invasividade Neoplásica
16.
Br J Dermatol ; 145(3): 415-21, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11531830

RESUMO

BACKGROUND: Topical immunotherapy with a contact allergen is effective in alopecia areata (AA). However, the mechanism of the effect is still unknown, and pretreatment prediction of the outcome of therapy in each patient remains difficult. OBJECTIVES: To predict the clinical effect of this therapy in AA patients, we investigated the relationship between clinical responses to topical immunotherapy and in vitro proliferative responses of peripheral blood mononuclear cells (PBMC) to T-cell stimulants. METHODS: PBMC were taken from 67 AA patients before or during diphenylcyclopropenone immunotherapy and from 14 healthy controls, and proliferative responses to phytohaemagglutinin and staphylococcal enterotoxin B were evaluated by measuring [3H]-thymidine incorporation. RESULTS: PBMC from the AA patients with a good clinical response to immunotherapy showed a normal level of proliferation, whereas PBMC from the poor responders showed a markedly suppressed proliferative response and interleukin (IL)-2 production, but increased IL-4 production compared with the controls. CONCLUSIONS: The proliferative response of PBMC to T-cell stimulants may be one of the indicators of the clinical effect of topical immunotherapy for AA.


Assuntos
Alérgenos/uso terapêutico , Alopecia em Áreas/terapia , Ciclopropanos/imunologia , Imunoterapia/métodos , Linfócitos T/imunologia , Adolescente , Adulto , Alopecia em Áreas/imunologia , Técnicas de Cultura de Células , Divisão Celular/imunologia , Criança , Citocinas/biossíntese , Enterotoxinas/imunologia , Feminino , Humanos , Tolerância Imunológica , Masculino , Pessoa de Meia-Idade , Fito-Hemaglutininas/imunologia , Prognóstico , Resultado do Tratamento
17.
J Dermatol Sci ; 27(2): 147-51, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11532379

RESUMO

Since acne formation is a multistep process accelerated by androgens, we examined whether a new anti-acne antibiotic roxithromycin (RXM) may act as anti-androgen using transient transfection assays in human skin fibroblasts. The result showed no significant effect of 0.5, 1 and 5 microg/ml RXM on 10(-9) M R1881-induced androgen receptor (AR) transcriptional activity. While the cotransfection of exogenous ARA55, a novel AR coactivator, increased AR transactivation up to 2.59-fold, this increase was attenuated by 5 microg/ml RXM to 64.7%. Semiquantitative RT-PCR results showed that 0.1 mM H(2)O(2) treatment increased ARA55 mRNA expression level, indicating that reactive oxygen species increase the expression of ARA55 in skin. These results suggest that RXM may serve as anti-androgen only in the hypersensitive state to androgen, but not in the physiological state, through modulating end-organ hypersensitive condition to androgen possibly involving the pathway from reactive oxygen species to ARA55.


Assuntos
Antagonistas de Androgênios , Fibroblastos/efeitos dos fármacos , Metribolona/farmacologia , Roxitromicina/farmacologia , Pele/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Relação Dose-Resposta a Droga , Fibroblastos/citologia , Fibroblastos/metabolismo , Genes Reporter , Humanos , Luciferases/análise , Luciferases/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/citologia , Ativação Transcricional/efeitos dos fármacos , Transfecção
18.
J Immunol ; 167(6): 3156-63, 2001 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-11544301

RESUMO

A novel IFN-like molecule, limitin, was recently identified and revealed to suppress B lymphopoiesis through the IFN-alphabeta receptor, although it lacked growth suppression on myeloid and erythroid progenitors. Here we have studied diverse effects of limitin on T lymphocytes and compared limitin with previously known IFNs. Like IFN-alpha and -beta, limitin modified immunity in the following responses. It suppressed mitogen- and Ag-induced T cell proliferation through inhibiting the responsiveness to exogenous IL-2 rather than suppressing the production of IL-2. In contrast, limitin enhanced cytotoxic T lymphocyte activity associated with the perforin-granzyme pathway. To evaluate the effect of limitin in vivo, a lethal graft-versus-host disease assay was established. Limitin-treatment of host mice resulted in the enhancement of graft-versus-host disease. Limitin did not influence thymocyte development either in fetal thymus organ cultures or in newborn mice injected with limitin-Ig, suggesting that limitin is distinguishable from IFN-alpha and -beta. From these findings, it can be speculated that the human homolog of limitin may be applicable for clinical usage because of its IFN-like activities with low adverse effects on, for example, T lymphopoiesis, erythropoiesis, and myelopoiesis.


Assuntos
Citocinas/fisiologia , Ativação Linfocitária/efeitos dos fármacos , Subpopulações de Linfócitos T/efeitos dos fármacos , Adjuvantes Imunológicos/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Citocinas/efeitos dos fármacos , Citocinas/toxicidade , Citotoxicidade Imunológica , Avaliação Pré-Clínica de Medicamentos , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/imunologia , Hematopoese/efeitos dos fármacos , Imunossupressores/farmacologia , Interferon-alfa/farmacologia , Interferon beta/farmacologia , Interleucina-2/análise , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Muromonab-CD3/farmacologia , Técnicas de Cultura de Órgãos , Ovalbumina/imunologia , Quimera por Radiação , Subpopulações de Linfócitos T/imunologia , Timo/citologia , Timo/embriologia
19.
Immunity ; 15(2): 261-73, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11520461

RESUMO

This study describes abnormalities of the thymus in mice in which the Stat3 gene has been specifically disrupted behind the keratin 5 promoter. In these mice, virtually all of the thymic epithelial cells (TEC) were deficient for Stat3 activation. Adult mutant mice developed severe thymic hypoplasia, which included alterations in the cortical TEC architecture that coincided with the loss of thymocytes. Even during the asymptomatic period of preadolescence, these mice exhibited a higher susceptibility of the thymus to suboptimal doses of dexamethasone or gamma-irradiation, while their thymocytes per se were no more sensitive than controls. These results indicate that Stat3 in TEC plays an essential role in maintaining thymic architecture and thymocyte survival.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Células Epiteliais/patologia , Linfócitos T/citologia , Timo/patologia , Transativadores/metabolismo , Animais , Apoptose , Sobrevivência Celular , Proteínas de Ligação a DNA/genética , Dexametasona/farmacologia , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Células Epiteliais/citologia , Células Epiteliais/efeitos da radiação , Raios gama , Camundongos , Camundongos Mutantes , Regeneração , Fator de Transcrição STAT3 , Transdução de Sinais , Timo/citologia , Timo/crescimento & desenvolvimento , Timo/efeitos da radiação , Transativadores/genética , Regulação para Cima
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