Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Topoisomerase 1 is required for the development and function of thymus

ABSTRACT: Thymus organogenesis is critical for proper maturation of developing T cells. In this study, we identified Topoisomerase 1 (Top1) as a novel gene involved in thymus development and function. We created a mouse line with deletion of Top1 in thymic epithelial cells (TECs) and our results demonstrate that biallelic loss of Top1 in TECs causes congenital thymic aplasia, precipitating T cell immunodeficiency. Transcriptomic analysis provides insights into the molecular mechanism of Top1 in thymus development as we identify key genes involved in thymus organogenesis as the transcriptional targets of Top1 in TECs. Analysis of peripheral immunological compartments revealed severe loss of ab T cells complemented with a disproportionate accumulation of gd T cells and myeloid cells upon deletion of Top1 in TECs. The residual ab T cells in Top1 knock-out mice were effector and oligoclonal in nature highlighting their possible self-reactivity. These results reveal a previously unknown role of Top1 in thymus development and T cell homeostasis. We propose Top1 as a genetic target for altered thymic development and T cell lymphopenia.

ORGANISM(S): Mus musculus

PROVIDER: GSE277209 | GEO | 2025/04/28

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Thymic epithelial cells induce formation of mesenchymal network structure after abrogation of thymic crosstalk

Project description:In the earliest step of thymic organogenesis, mesenchymal cells support the growth of thymic epithelial cells (TECs). It is established that TECs and thymocytes influence each other for their growth/differentiation, a process called thymic crosstalk. However, little is known about the influence of developing thymocytes or TECs on mesenchymal cells. Here, we show that during normal thymus development fibroblast ingrowth occurs towards hypoxic areas. Similar overgrowth of mesenchymal cells is seen in a fetal thymic organ culture system under low oxygen conditions. However, when thymocytes were depleted by deoxyguanosine treatment, mesenchymal cells were also induced, precluding the direct effect of hypoxia. In the fetal thymus of hCD3εTg mice, which lack T lineage cells, an overgrowth of mesenchymal cells can be seen at a very early stage of thymic organogenesis. The growth of the mesenchymal cells is due to extensive proliferation and not mere enrichment. With RNA sequencing analysis comparing hCD3εTg with wild type TECs, we identified candidate factors that could be involved in mesenchymal network formation.

2017-08-19 | GSE60520 | GEO

CD90 marks a mesenchymal program in human thymic epithelial cells in vitro and in vivo

Project description:Thymic epithelium is critical for the structural integrity of the thymus and for T cell development. Within the fully formed thymus, large numbers of hematopoietic cells shape the thymic epithelium into a scaffold-like structure which bears little similarity to classical epithelial layers, such as those observed in the skin, intestine or pancreas. Here, we show that human thymic epithelial cells (TECs) possess an epithelial identity that also incorporates the expression of mesenchymal cell associated genes, whose expression levels vary between medullary and cortical TECs (m/cTECs). Using pluripotent stem cell (PSC) differentiation systems, we identified a unique population of cells that co-expressed the master TEC transcription factor FOXN1, as well as the epithelial associated marker EPCAM and the mesenchymal associated gene CD90. Using the same serum free culture conditions, we also observed co-expression of EPCAM and CD90 on cultured TECs derived from neonatal human thymus in vitro. Single cell RNA-sequencing revealed these cultured TECs possessed an immature mTEC phenotype and expressed epithelial and mesenchymal associated genes, such as EPCAM, CLDN4, CD90 and COL1A1. Importantly, flow cytometry and single cell RNA-sequencing analysis further confirmed the presence of an EPCAM+CD90+ population in the CD45- fraction of neonatal human thymic stromal cells in vivo. Using the human thymus cell atlas, we found that cTECs displayed more pronounced mesenchymal characteristics than mTECs during embryonic development. Collectively, these results suggest human TECs possess a hybrid gene expression program comprising both epithelial and mesenchymal elements, and provide a basis for the further exploration of thymus development from primary tissues and from the in vitro differentiation of PSCs.

2022-02-28 | GSE196005 | GEO

microRNA expression in thymic epithelial cells

Project description:Thymic epithelial cells (TECs) support T cell development in the thymus. Cortical thymic epithelial cells (cTECs) facilitate positive selection of developing thymocytes whereas medullary thymic epithelial cells (mTECs) facilitate the deletion of self-reactive thymocytes in order to prevent autoimmunity. The mTEC compartment is highly dynamic with continuous maturation and turnover, but the genetic regulation of these processes remains poorly understood. MicroRNAs (miRNAs) are important regulators of TEC genetic programs since miRNA-deficient TECs are severely defective. However, the individual miRNAs important for TEC maintenance and function and their mechanisms of action remain unknown. Here, we demonstrate that miR-205 is highly and preferentially expressed in mTECs during both thymic ontogeny and in the postnatal thymus. This distinct expression is suggestive of functional importance for TEC biology. Genetic ablation of miR-205 in TECs, however, neither revealed a role for miR-205 in TEC function during homeostatic conditions nor during recovery from thymic stress conditions. Thus, despite its distinct expression, miR-205 on its own is largely dispensable for mTEC biology. In order to identify miRNAs differentially expressed in mTECs, we purified cortical thymic epithelial cells (cTECs), mTECs and CD45+ cells as three distinct populations and prepared RNA for microarray analysis. Thymic subsets were FACS-purified from 4-week old NOD wildtype mice. Thymi from 10-12 female mice were pooled together for stromal cell isolation for a total of 3 CD45+, 2 cTEC and 3 mTEC biologic replicates.

2015-07-28 | E-GEOD-68674 | biostudies-arrayexpress

Next-generation sequencing of cTEC and mTEC isolated from non-pregnant and pregnant females lacking the expression of Klf4 (KO) or not (LOX)

Project description:Stress-induced thymic involution is defined by profound damage to thymic epithelial cells (TECs), resulting in an acute and transient reduction of thymopoietic capacity. During pregnancy, thymic involution is not associated with TEC loss but rather with TEC quality modifications. Study of the mechanisms of TEC maintenance during pregnancy may be of critical importance for identifying new players for thymic regeneration in other models of thymic involution. We report a strong enrichment for motifs recognized by KLF4 based on genes differentially expressed in TECs of pregnant females. Therefore, we studied the impact of Klf4 deletion in TECs during pregnancy by analyzing thymus composition and TEC transcriptome. Conditional Klf4 deletion in homeostatic conditions does not injure thymic integrity. However, pregnant females lacking Klf4 show a disrupted thymus with substantial loss of thymic epithelial cells. Klf4 maintains cTEC number during pregnancy by maintaining cell survival and inhibiting the transition to a mesenchymal state. Our study reveals Klf4 as a protective factor for TECs during pregnancy-associated thymic involution and represents a potential study subject for other models of stress-induced thymic involution.

2022-09-30 | GSE210885 | GEO

microRNA expression in thymic epithelial cells

2015-07-28 | GSE68674 | GEO

Generation of a functional, patient specific human thymus from induced pluripotent stem cell in vivo

Project description:Here we describe a universal direct differentiation protocol that allows the generation of thymic epithelial progenitor cells (TEPs) from different iPSC lines. Upon transplantation into an athymic mouse model, TEPs further differentiate into thymic epithelial cells (TECs). TECs are functional and can facilitate the education of developing mouse T-cells. iPSC derived, patient specific TECs residing within grafts are indistinguishable from TECs present in human primary neonatal thymus tissue as revealed by single cell RNA sequencing analysis indicating the generation of a mature TEC phenotype. Taken together, we provide a universal direct differentiation protocol that generates TEPs from all iPSC lines tested, that can further differentiate into mature, functional TECs. We anticipate that these findings have important implications for current efforts aimed at generating a functional human thymus.

2021-09-24 | GSE148495 | GEO

Transcriptome analysis of thymic epithelial cells and thymic non-epithelial stromal cells from young, middle-aged and castrated middle-aged male mice

Project description:The thymus is primarily responsible for generating naïve, self-tolerant T cells from hematopoietic precursors. Thymic epithelial cells (TECs) together with other stromal cells create a specialized microenvironment which orchestrates the major selection processes for T cell development. Thymic function progressively deteriorates as part of the aging process, with a dramatic loss in TECs and T cell production, and this ultimately constrains the host immune repertoire. We have previously demonstrated the role of sex steroids in thymic involution in male mice, with surgical castration of middle-aged (9-12 month) male mice resulting in thymus regeneration, peaking around day 28. We have also demonstrated phenotypic alterations in TEC subsets within one week following castration that may contribute to this transient thymus regeneration effect. In this study, we aimed to examine genetic alterations in TEC and non-TEC stromal cell subsets (predominantly fibroblasts and endothelial cells) during age-related thymic involution (5-6 week old young adults compared to 9-12 month middle aged); and genetic changes in TEC and non-TEC at several timepoints following castration, to identify factors that may be involved in thymus regeneration.

2019-06-06 | GSE132278 | GEO

Comparison of thymic epithelial cells and hair follicle stem cells

Project description:Thymic epithelial cells (TECs) are essential for thymopoiesis and form a complex three-dimensional network, the organization of which is strikingly different from other epithelia. Interestingly, TECs express simple epithelia keratins in the cortex, stratified epithelia keratins in the medulla and epidermal differentiation markers in Hassall's bodies. Here we investigate the relationship between thymic epithelium and epidermal differentiation and show that the thymus of the rat contains a population of clonogenic TECs that can be extensively cultured and cloned using conditions developed for epidermal cell therapy in human. Clonogenic TECs conserve a thymic identity and the capacity to integrate in a thymic epithelial network, but they acquire new functionalities when exposed to an inductive skin microenvironment, permanently adopting the fate of hair follicle multipotent stem cells. This change in fate, maintained over time in serial transplantation, correlates with a down-regulation of transcription factors important for thymic identity, and an up-regulation of epidermal markers. Consequently, the TECs’ capacity to integrate in a thymic epithelial network is altered or even lost. Our results demonstrate that the thymus contains a population of holoclone-like epithelial cells that can function as bona fide multipotent keratinocyte stem cells, and that microenvironmental cues are sufficient to re-direct epithelial-cell fate, allowing crossing of primitive germ layer boundaries from endoderm to ectoderm. Keywords: Cell type comparison

2010-08-23 | GSE21686 | GEO

Ovol2 sustains postnatal thymic epithelial cell identity

Project description:Thymic epithelial cells (TECs) begin to develop embryonically in mice and humans, expand in number through puberty, and then stabilize before declining during early adulthood. We identified a mechanism by which TEC numbers and function are maintained postnatally, discovered through a forward genetic screen for altered immune cell development in mice. A viable missense allele (C120Y) of Ovol2 resulted in lymphopenia, in which T cell development was compromised by loss of medullary TECs and dysfunction of cortical TECs. OVOL2 is an essential regulator of epithelial to mesenchymal transition (EMT), and we show that the epithelial identity of TECs is subverted towards a mesenchymal state in OVOL2-deficient mice. We document global changes in chromatin accessibility correlated with gene expression, particularly affecting genes involved in epithelial and mesenchymal cell proliferation and differentiation. OVOL2 regulates chromatin accessibility by inhibiting the BRAF-HDAC complex. In particular, it disrupts the RCOR1-LSD1 complex by directly binding to the lysine demethylase LSD1, resulting in inhibition of LSD1-mediated H3K4me2 demethylation. Thus, OVOL2 controls the epigenetic landscape of TECs, preventing EMT and enforcing TEC identity to support T cell development in the thymus.

2022-12-21 | MSV000090946 | MassIVE

Single-cell RNA sequencing of non-hematopoietic cells from mouse thymus spanning embryonic and adult stages

Project description:Here we constructed a single-cell transcriptional landscape of non-hematopoietic cells from mouse thymus spanning embryonic and adult stages, producing transcriptomes of 30,959 TECs. We resolved transcriptional heterogeneity of developing TECs, and highlighted the molecular nature of early TEC lineage determination and cortico-medullary thymic epithelial cell lineage divergency.

2022-03-17 | GSE192480 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data