RESUMO
The differentiation of neural crest (NC) cells into various cell lineages contributes to the formation of many organs, including the thymus. In this study, we explored the role of NC cells in thymic T cell development. In double-transgenic mice expressing NC-specific Cre and the Cre-driven diphtheria toxin receptor, plasma noradrenaline and adrenaline levels were significantly reduced, as were thymic T cell progenitors, when NC-derived cells were ablated with short-term administration of diphtheria toxin. Additionally, yellow fluorescent protein+ NC-derived mesenchymal cells, perivascular cells, and tyrosine hydroxylase+ sympathetic nerves in the thymus significantly decreased. Furthermore, i.p. administration of 6-hydroxydopamine, a known neurotoxin for noradrenergic neurons, resulted in a significant decrease in thymic tyrosine hydroxylase+ nerves, a phenotype similar to that of depleted NC-derived cells, whereas administration of a noradrenaline precursor for ablating NC-derived cells or sympathetic nerves rarely rescued this phenotype. To clarify the role of NC-derived cells in the adult thymus, we transplanted thymus into the renal capsules of wild-type mice and observed abnormal T cell development in lethally irradiated thymus with ablation of NC-derived cells or sympathetic nerves, suggesting that NC-derived cells inside and outside of the thymus contribute to T cell development. In particular, the ablation of NC-derived mesenchymal cells in the thymus decreases the number of thymocytes and T cell progenitors. Overall, ablation of NC-derived cells, including sympathetic nerves, in the thymus leads to abnormal T cell development in part by lowering plasma noradrenalin levels. This study reveals that NC-derived cells including mesenchymal cells and sympathetic nerves within thymus regulate T cell development.
Assuntos
Crista Neural , Norepinefrina , Camundongos , Animais , Tirosina 3-Mono-Oxigenase , Diferenciação Celular , Camundongos Transgênicos , TimoRESUMO
Secondary osteoporosis can also be caused by chronic inflammatory skin disease as well as rheumatoid arthritis or inflammatory bowel disease. However, the exact role of osteoporosis in inflammatory skin conditions has not been elucidated. Using a mouse model of dermatitis, we investigated the pathophysiology of osteoporosis in inflammatory skin conditions and the therapeutic impact of osteoporosis medication on inflammatory skin disease. We employed model mice of spontaneous skin inflammation, specifically overexpressing human caspase-1 in the epidermis. Bone density and the expression of various mRNAs in the femur were examined by micro CT and RT-PCR. The effects of minodronate and anti-RANKL antibody on bone structure, histology, and femur blood flow were studied. The mouse model of skin inflammation showed a marked decrease in bone density compared to wild-type littermates with abnormalities in both bone resorption and formation. Minodronate improved bone density by decreasing osteoclasts, but anti-RANKL antibody did not improve. In the dermatitis model, the blood flow in the bone marrow was decreased, and minodronate restored this parameter. A model of persistent dermatitis exhibited marked osteoporosis, but the impact of chronic dermatitis on osteoporosis has not been thoroughly investigated. We should explore the pathogenesis of osteoporosis in skin inflammatory diseases.
Assuntos
Citocinas/metabolismo , Osteoporose/metabolismo , Psoríase/metabolismo , Animais , Densidade Óssea , Conservadores da Densidade Óssea/farmacologia , Conservadores da Densidade Óssea/uso terapêutico , Remodelação Óssea , Caspase 1/metabolismo , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Feminino , Fêmur/irrigação sanguínea , Fêmur/efeitos dos fármacos , Fêmur/metabolismo , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Osteoporose/tratamento farmacológico , Osteoporose/etiologia , Psoríase/complicações , Fluxo Sanguíneo RegionalRESUMO
Hematopoietic stem cells and their lymphoid progenitors are supported by the bone marrow (BM) microenvironmental niches composed of various stromal cells and Schwann cells and sympathetic nerve fibers. Although neural crest (NC) cells contribute to the development of all the three, their function in BM is not well understood. In this study, NC-derived cells were ablated with diphtheria toxin in double-transgenic mice expressing NC-specific Cre and Cre-driven diphtheria toxin receptor with yellow fluorescent protein reporter. We found that yellow fluorescent protein-expressing, NC-derived nonhematopoietic cells in BM expressed hematopoietic factors Cxcl12 and stem cell factor The ablation of NC-derived cells led to a significant decrease in B cell progenitors but not in hematopoietic stem cells or myeloid lineage cells in BM. Interestingly, plasma noradrenaline was markedly decreased in these mice. The i.p. administration of 6-hydroxydopamine, a known neurotoxin for noradrenergic neurons, led to a similar phenotype, whereas the administration of a noradrenaline precursor in NC-ablated mice partially rescued this phenotype. Additionally, the continuous administration of adrenergic receptor ß antagonists partially decreased the number of B cell progenitors while preserving B lymphopoiesis in vitro. Taken together, our results indicate that NC-derived cell depletion leads to abnormal B lymphopoiesis partially through decreased plasma noradrenaline, suggesting this as a novel mechanism regulated by molecules released by the sympathetic neurons.
Assuntos
Linfócitos B/citologia , Linfopoese/fisiologia , Crista Neural/citologia , Norepinefrina/sangue , Animais , Diferenciação Celular , Separação Celular , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Crista Neural/imunologia , Reação em Cadeia da PolimeraseRESUMO
Formation of the hematopoietic cells occurs in multiple steps. The first hematopoietic cells observed during ontogeny are primitive erythrocytes, which are produced in the early yolk sac within a limited temporal window. Multi-lineage hematopoiesis, which supplies almost the entire repertoire of blood cell lineages, lags behind primitive erythropoiesis in the tissue. However, molecular mechanisms regulating sequential generation of primitive erythrocytes and multipotent hematopoietic progenitors in the yolk sac are largely unknown. In this study, the transcription factors involved in the development of hematopoietic cells were examined in purified progenitor cell populations from pluripotent stem cell cultures and from the yolk sac of developing embryos. We found that the earliest committed hematopoietic progenitors highly expressed Gata1, Scl/tal1, and Klf1 genes. Expression of these transcription factors, which is known to form a core erythroid transcriptional network, explained the prompt generation of primitive erythrocytes from these earliest progenitors. Importantly, the multipotent hematopoietic cells, which lack the differentiation potential into primitive erythroid cells, down-regulated these genes during a transition from the earliest committed progenitors. In addition, we showed that Pu.1 is involved in the multipotent cell differentiation through the suppression of erythroid transcription program. We propose that these molecular mechanisms governed by transcription factors form sequential waves of primitive erythropoiesis and multi-lineage hematopoiesis in the early yolk sac of developing embryos. J. Cell. Physiol. 232: 323-330, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
Linhagem da Célula , Desenvolvimento Embrionário , Células Eritroides/citologia , Hematopoese , Animais , Diferenciação Celular , Eritrócitos/metabolismo , Células Eritroides/metabolismo , Feminino , Antígenos Comuns de Leucócito/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Saco Vitelino/metabolismoAssuntos
Dessensibilização Imunológica , Vetores Genéticos/imunologia , Interleucina-10/imunologia , Mucosa Nasal/imunologia , Paramyxoviridae/imunologia , Rinite Alérgica Sazonal/imunologia , Animais , Modelos Animais de Doenças , Vetores Genéticos/genética , Humanos , Interleucina-10/genética , Leucócitos/imunologia , Leucócitos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Mucosa Nasal/patologia , Paramyxoviridae/genética , Rinite Alérgica Sazonal/genética , Rinite Alérgica Sazonal/patologia , Rinite Alérgica Sazonal/terapiaRESUMO
Follicular dendritic cells (FDCs) are non-hematopoietic cells that are localized in the germinal centers (GCs) of lymph nodes (LNs) and are involved in humoral immunity. FDCs are a rare population that are sensitive to mechanical and chemical stimuli, making their isolation for analysis difficult. In Peyer's Patches, which are the main IgA-inductive sites, FDCs have been reported to be activated by retinoic acid receptor (RAR) and toll-like receptor (TLR) signals to induce IgA production. However, little is known about FDCs in mesenteric LNs (MLNs), although MLNs are also an IgA-inductive site. In this study, we efficiently isolated FDCs as CD35+ cells using anti-CD35 antibodies (Abs) and magnetic bead sorting. We found that CD35+ FDCs facilitated differentiation from B220+ B cells into IgA+GL7+ GC B-like cells but not IgA+CD138+ plasma cells. Furthermore, using CD35+ FDCs from LPS-resistant C3H/HeJ mice, the generation of IgA+GL7+ GC B-like cells was not altered significantly between wild-type and LPS-resistant mice. Moreover, the addition of RAR antagonists and agonists revealed that differentiation into IgA+GL7+ GC B-like cells required the activation of RAR, especially RAR-ß, in FDCs. The differentiation of IgA+GL7+ cells was promoted by FDCs in peripheral LNs as well as MLNs in our in vitro assay. Taken together, these results indicate that magnetic bead sorting with anti-CD35 Abs enable the efficient isolation of FDCs. Our data suggested that CD35+ FDCs can support differentiation of B cells into IgA+GL7+ GC B-like cells in environments that are not limited to MLNs, which can be stimulated by retinoic acid.
Assuntos
Células Dendríticas Foliculares , Lipopolissacarídeos , Animais , Centro Germinativo , Imunoglobulina A , Camundongos , Camundongos Endogâmicos C3HRESUMO
Mesenchymal cells arise from the neural crest (NC) or mesoderm. However, it is difficult to distinguish NC-derived cells from mesoderm-derived cells. Using double-transgenic mouse systems encoding P0-Cre, Wnt1-Cre, Mesp1-Cre, and Rosa26EYFP, which enabled us to trace NC-derived or mesoderm-derived cells as YFP-expressing cells, we demonstrated for the first time that both NC-derived (P0- or Wnt1-labeled) and mesoderm-derived (Mesp1-labeled) cells contribute to the development of dental, thymic, and bone marrow (BM) mesenchyme from the fetal stage to the adult stage. Irrespective of the tissues involved, NC-derived and mesoderm-derived cells contributed mainly to perivascular cells and endothelial cells, respectively. Dental and thymic mesenchyme were composed of either NC-derived or mesoderm-derived cells, whereas half of the BM mesenchyme was composed of cells that were not derived from the NC or mesoderm. However, a colony-forming unit-fibroblast (CFU-F) assay indicated that CFU-Fs in the dental pulp, thymus, and BM were composed of NC-derived and mesoderm-derived cells. Secondary CFU-F assays were used to estimate the self-renewal potential, which showed that CFU-Fs in the teeth, thymus, and BM were entirely NC-derived cells, entirely mesoderm-derived cells, and mostly NC-derived cells, respectively. Colony formation was inhibited drastically by the addition of anti-platelet-derived growth factor receptor-ß antibody, regardless of the tissue and its origin. Furthermore, dental mesenchyme expressed genes encoding critical hematopoietic factors, such as interleukin-7, stem cell factor, and cysteine-X-cysteine (CXC) chemokine ligand 12, which supports the differentiation of B lymphocytes and osteoclasts. Therefore, the mesenchymal stem cells found in these tissues had different origins, but similar properties in each organ.