Transcription Factor TLX1 Controls Retinoic Acid Signaling to Ensure Spleen Development
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Andrea Brendolan
PROVIDER: E-GEOD-81661 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The molecular mechanisms underlying asplenia, a condition often associated with overwhelming infections remain largely unknown. During spleen development, the transcription factor TLX1 controls morphogenesis and organ expansion, and loss of it causes spleen agenesis. However, the downstream signaling pathways that are deregulated in the absence of TLX1 are mostly unknown. Herein, we demonstrate that loss of Tlx1 in the splenic mesenchyme causes increased retinoic acid (RA) signaling. Increased RA activity causes premature differentiation of the splenic mesenchyme and reduced vasculogenesis of the splenic anlage. Moreover, excess or deficiency in RA signaling, as observed in Cyp26b1 or Rdh10 mutants respectively, also results in spleen growth arrest. Genome-wide analysis revealed that TLX1 binds RA-associated genes through the AP-1 site and cooperates with the AP-1 family transcription factors to regulate transcription. Pharmacological inhibition of RA signaling partially rescues the spleen defect. These findings establish the critical role of TLX1 in controlling RA metabolism, and provide novel mechanistic insights into the molecular determinants underlying congenital asplenia. Samples: 3 replicates of E13.5 spleens from Tlx1 heterozygous embryos were compared to 3 replicates of E13.5 spleens from Tlx1 homozygous embryos
2016-07-01 | E-GEOD-68519 | biostudies-arrayexpress
Project description:The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1-deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insight into the molecular determinants of human congenital asplenia. We performed ChIP-sequencing for Hox11 rep1 and rep2 in eSMC untreated cells.
2016-07-01 | E-GEOD-81660 | biostudies-arrayexpress
Project description:The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1-deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome P450 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insights into the molecular determinants of human congenital asplenia.
| S-EPMC4922703 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2016-07-01 | GSE81661 | GEO
Project description:The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1-deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insight into the molecular determinants of human congenital asplenia.
2016-07-01 | GSE81660 | GEO
Project description:The molecular mechanisms underlying asplenia, a condition often associated with overwhelming infections remain largely unknown. During spleen development, the transcription factor TLX1 controls morphogenesis and organ expansion, and loss of it causes spleen agenesis. However, the downstream signaling pathways that are deregulated in the absence of TLX1 are mostly unknown. Herein, we demonstrate that loss of Tlx1 in the splenic mesenchyme causes increased retinoic acid (RA) signaling. Increased RA activity causes premature differentiation of the splenic mesenchyme and reduced vasculogenesis of the splenic anlage. Moreover, excess or deficiency in RA signaling, as observed in Cyp26b1 or Rdh10 mutants respectively, also results in spleen growth arrest. Genome-wide analysis revealed that TLX1 binds RA-associated genes through the AP-1 site and cooperates with the AP-1 family transcription factors to regulate transcription. Pharmacological inhibition of RA signaling partially rescues the spleen defect. These findings establish the critical role of TLX1 in controlling RA metabolism, and provide novel mechanistic insights into the molecular determinants underlying congenital asplenia.
2016-07-01 | GSE68519 | GEO
Project description:Transcription Factor TLX1 Controls Retinoic Acid Signaling to Ensure Spleen Development
| PRJNA322247 | ENA
Project description:Extramedullary hematopoiesis (EMH) in postnatal life is a pathological process in which the differentiation of hematopoietic stem/progenitor cells (HSPCs) occurs outside the bone marrow (BM) to respond to hematopoietic emergencies. The spleen is a major site for EMH; however, the cellular and molecular nature of the stromal cell components supporting HSPC maintenance, the niche for EMH in the spleen remain poorly understood compared to the growing understanding of the BM niche at the steady-state as well as in emergency hematopoiesis. In the present study, we demonstrate that mesenchymal progenitor-like cells expressing Tlx1, an essential transcription factor for spleen organogenesis, and selectively localized in the perifollicular region of the red pulp of the spleen, are a major source of HSPC niche factors. Consistently, overexpression of Tlx1 in situ induces EMH, which is associated with mobilization of HSPC into the circulation and their recruitment into the spleen where they proliferate and differentiate. The alterations in the splenic microenvironment induced by Tlx1 overexpression in situ phenocopy lipopolysaccharide (LPS)-induced EMH, and the conditional loss of Tlx1 abolished LPS-induced splenic EMH. These findings indicate that activation of Tlx1 expression in the postnatal splenic mesenchymal cells is critical for the development of splenic EMH.
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Project description:The spleen is comprised of spatially distinct compartments whose functions, such as immune responses and removal of aged red blood cells, are tightly controlled by the non-hematopoietic stromal cells that provide regionally-restricted signals to properly activate hematopoietic cells residing in each area. However, information regarding the ontogeny and relationships of the different stromal cell types remains limited. Here we have used in vivo lineage tracing analysis and in vitro mesenchymal stromal cell assays and found that Tlx1, a transcription factor essential for embryonic spleen organogenesis, marks neonatal stromal cells that are selectively localized in the spleen and retain mesenchymal progenitor potential to differentiate into mature follicular dendritic cells, fibroblastic reticular cells and marginal reticular cells. Furthermore, by establishing a novel three-dimensional cell culture system that enables maintenance of Tlx1-expressing cells in vitro, we discovered that signals from the lymphotoxin ? receptor and TNF receptor promote differentiation of these cells to express MAdCAM-1, CCL19 and CXCL13, representative functional molecules expressed by different subsets of mature stromal cells in the spleen. Taken together, these findings indicate that mesenchymal progenitor cells expressing Tlx1 are a subset of lymphoid tissue organizer-like cells selectively found in the neonatal spleen.
| S-EPMC6938487 | biostudies-literature
Project description:Sequential differentiation of presomitic progenitors into myocytes and subsequently into myotubes and myofibers is essential for the myogenic differentiation program (MDP) crucial for muscle development. Signaling factors involved in MDP are polycomb repressive complex 2 (PRC2) targets in various developmental contexts. PRC2 is active in the developing myotomes during MDP, but how it regulates MDP is unclear. Here, we found that myocyte differentiation to myotubes requires Enhancer of Zeste 2 (EZH2), the catalytic component of PRC2. We observed elevated retinoic acid (RA) signaling in the prospective myocytes in the Ezh2 mutants (E8.5-MusEzh2 ), and its inhibition can partially rescue the myocyte differentiation defect. Together, our data demonstrate a new role for PRC2-EZH2 during myocyte differentiation into myotubes by modulating RA signaling.
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