GO:0098508 endothelial to hematopoietic transition: Developmental Process, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0098508 describes the generation of hematopoietic stem cells from hemogenic endothelial cells through tight-junction dissolution, loss of cell polarity, and delamination from the endothelium.
• The process is a specialized endothelial-to-hematopoietic transition (EHT) that occurs in the aorta-gonad-mesonephros (AGM) region and is conserved in human induced pluripotent stem cell (iPSC) models.
• Notch signaling, N-glycosylation, and Robo4 are key regulators of EHT, with Notch controlling hemogenic endothelium specification and N-glycome modulating the transition.
• Signal requirements shift during hematopoietic stem cell development from hemogenic endothelial cells, with distinct cytokine dependencies at different stages.
• EHT is distinct from endothelial-to-mesenchymal transition (EndoMT), which contributes to cardiac fibrosis and bone marrow fibrosis but is not the same biological process.
• Studying EHT is essential for regenerative medicine, leukemia research, and understanding developmental hematopoiesis, with CRISPR screens and iPSC models enabling mechanistic dissection.
Description
Endothelial to hematopoietic transition (EHT) is the developmental process by which hemogenic endothelial cells generate hematopoietic stem cells (HSCs). This process, annotated as GO:0098508, is characterized by tight-junction dissolution, loss of cell polarity, and delamination from the endothelial layer. EHT is a critical step in embryonic hematopoiesis and is conserved in human induced pluripotent stem cell (iPSC) models, making it a tractable system for studying HSC development. Researchers study EHT to understand the origins of blood stem cells, to improve in vitro HSC generation for transplantation, and to uncover mechanisms of leukemogenesis. The process is regulated by a complex interplay of signaling pathways, including Notch and N-glycosylation, which control the timing and efficiency of the transition. Defects in EHT are linked to hematopoietic failure and have implications for bone marrow reconstitution and fibrosis.
endothelial to hematopoietic transition At A Glance
| GO ID | GO:0098508 |
|---|---|
| GO term | endothelial to hematopoietic transition |
| Ontology | biological_process |
| Synonym | none |
| Major function | Generation of hematopoietic stem cells from hemogenic endothelial cells via tight-junction dissolution, loss of cell polarity, and delamination |
| Related process | Endothelial-to-mesenchymal transition (EndoMT) is a distinct process contributing to fibrosis |
| Key regulators | Notch signaling, N-glycosylation, Robo4, and stage-specific cytokines |
| Model systems | Mouse AGM region, human iPSC-derived hemogenic endothelium, zebrafish |
What Is GO:0098508?
GO:0098508, endothelial to hematopoietic transition, is defined as the generation of hematopoietic stem cells from hemogenic endothelial cells by a process that includes tight-junction dissolution and loss of cell polarity followed by delamination from the endothelium. In simpler terms, it is the biological process where specialized endothelial cells lining blood vessels change their identity to become blood-forming stem cells, detaching from the vessel wall and entering the bloodstream.
Why Is endothelial to hematopoietic transition Important in Cell Biology?
EHT is fundamentally important because it represents the earliest step in the generation of hematopoietic stem cells, which are responsible for lifelong blood production. Understanding EHT provides insights into embryonic development, regenerative medicine, and the pathogenesis of blood disorders. The process is conserved from zebrafish to humans, and its dysregulation is associated with hematopoietic failure, bone marrow fibrosis, and leukemia. Moreover, the ability to recapitulate EHT in vitro from iPSCs holds promise for generating patient-specific HSCs for transplantation.
• EHT is the developmental origin of all hematopoietic stem cells, making it central to blood formation.
• Defects in EHT can lead to hematopoietic stem cell deficiencies and bone marrow failure.
• EHT is distinct from endothelial-to-mesenchymal transition, which contributes to cardiac and bone marrow fibrosis.
• Notch signaling is a master regulator of EHT, and its manipulation can enhance or impair HSC generation.
• N-glycosylation of cell surface proteins regulates EHT efficiency, linking glycosylation to developmental hematopoiesis.
• Robo4 suppresses endothelial-to-mesenchymal transition and improves hematopoietic reconstitution, highlighting cross-talk between EHT and EndoMT.
• Human iPSC models of EHT enable disease modeling and drug screening for blood disorders.
• Understanding EHT can inform strategies for generating HSCs in vitro for regenerative medicine.
• EHT research is relevant to leukemia, as leukemic stem cells may hijack developmental programs.
• CRISPR screens in EHT models can identify novel regulators of HSC development.
What Happens During endothelial to hematopoietic transition?
Specification of Hemogenic Endothelium
In simple terms: First, some endothelial cells in the embryo are told to become blood-forming cells.
Hemogenic endothelium is specified within the dorsal aorta and other vascular beds through the action of signaling pathways such as Notch. Notch signaling is required for the emergence of hemogenic endothelial cells, and its inhibition blocks EHT. The N-glycome, the collection of N-linked glycans on cell surface proteins, also plays a role in specifying hemogenic endothelium, as alterations in glycosylation affect the transition. This specification step involves the expression of transcription factors such as RUNX1, which is essential for EHT.
Tight-Junction Dissolution and Loss of Polarity
In simple terms: The cells loosen their connections to neighbors and lose their sense of direction.
During EHT, hemogenic endothelial cells undergo tight-junction dissolution and loss of cell polarity, as defined in GO:0098508. This step is critical for allowing the cells to detach from the endothelial layer. The process is regulated by changes in adhesion molecules and polarity complexes, although the exact molecular players are still being elucidated. N-glycosylation may influence cell adhesion and polarity during this transition.
Delamination from the Endothelium
In simple terms: The cells physically detach from the blood vessel wall and enter the circulation.
Following tight-junction dissolution and loss of polarity, hemogenic endothelial cells delaminate from the endothelium to become hematopoietic stem cells. This delamination step requires dynamic changes in cell-matrix interactions and is regulated by signaling pathways including Notch and cytokines. The transition of signal requirements during HSC development from hemogenic endothelial cells indicates that different factors are needed at this stage compared to earlier steps.
Maturation into Hematopoietic Stem Cells
In simple terms: The detached cells mature into fully functional blood stem cells.
After delamination, the newly formed hematopoietic stem cells undergo maturation and acquire the ability to self-renew and differentiate into all blood lineages. This maturation is influenced by the microenvironment and requires stage-specific signals, as shown by the transition of signal requirements from hemogenic endothelial cells to HSCs. Robo4, an endothelial receptor, suppresses endothelial-to-mesenchymal transition and improves hematopoietic reconstitution, suggesting that maintaining endothelial identity is important for proper HSC maturation.
Regulation by N-glycosylation
In simple terms: Sugar modifications on proteins control how well the transition happens.
The N-glycome regulates EHT, as demonstrated by studies showing that changes in N-linked glycosylation affect the efficiency of the transition. This regulation occurs at multiple steps, including specification and delamination, and highlights the importance of post-translational modifications in developmental hematopoiesis.
Key Genes Involved in GO:0098508 endothelial to hematopoietic transition
The following genes and proteins are key players in endothelial to hematopoietic transition, based on published literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| RUNX1 | Master transcription factor for EHT; essential for hemogenic endothelium specification | Knockout blocks EHT; mutations found in leukemia |
| NOTCH1 | Signaling receptor that specifies hemogenic endothelium | Inhibition impairs EHT; target for modulating HSC generation |
| ROBO4 | Endothelial receptor that suppresses EndoMT and improves hematopoietic reconstitution | Overexpression enhances HSC engraftment; link to fibrosis |
| GFI1 | Transcription factor involved in HSC development | Regulates EHT and hematopoietic differentiation |
| TAL1 | Transcription factor critical for hemogenic endothelium | Knockout impairs EHT; involved in T-cell leukemia |
| LMO2 | Transcription factor in hematopoietic development | Regulates EHT; oncogenic in leukemia |
| ERG | ETS transcription factor required for EHT | Knockout blocks HSC emergence; involved in leukemia |
| FLI1 | ETS transcription factor in hemogenic endothelium | Regulates EHT; target of Notch signaling |
| SCL/TAL1 | Transcription factor for blood development | Essential for EHT; mutations in leukemia |
| CD34 | Cell surface marker of hematopoietic progenitors | Used to identify HSCs derived from EHT |
| CD45 | Pan-leukocyte marker acquired during EHT | Marks hematopoietic cells after delamination |
| KDR/VEGFR2 | Receptor for VEGF; marks hemogenic endothelium | Required for EHT; target for modulation |
| RUNX1T1 | Transcriptional corepressor | Involved in EHT; fusion with RUNX1 in leukemia |
| SOX17 | Transcription factor in hemogenic endothelium | Regulates EHT; important for iPSC-derived HSCs |
| HOXA9 | Homeobox transcription factor | Promotes HSC development; involved in leukemia |
| MEIS1 | Homeobox transcription factor | Regulates HSC self-renewal; implicated in leukemia |
| NOTCH2 | Notch family receptor | Contributes to EHT regulation |
| JAG1 | Notch ligand | Activates Notch signaling during EHT |
How Is endothelial to hematopoietic transition Regulated?
EHT is regulated by multiple signaling pathways and post-translational modifications. Notch signaling is a key regulator, with Notch receptors and ligands controlling the specification of hemogenic endothelium and subsequent transition. The N-glycome, the repertoire of N-linked glycans, regulates EHT efficiency, as changes in glycosylation affect the transition. Robo4, an endothelial receptor, suppresses endothelial-to-mesenchymal transition and improves hematopoietic reconstitution, indicating that maintaining endothelial identity is important for proper EHT. Additionally, the signal requirements for HSC development from hemogenic endothelial cells change over time, with distinct cytokine dependencies at different stages. These regulatory mechanisms ensure that EHT occurs at the right time and place during development.
endothelial to hematopoietic transition and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| RUNX1 | Leukemia, familial platelet disorder | Knockout iPSCs, mouse models |
| ROBO4 | Bone marrow fibrosis, hematopoietic reconstitution | Overexpression in endothelial cells, mouse models |
| NOTCH1 | Leukemia, developmental defects | Knockout mice, iPSC-derived EHT |
| GFI1 | Hematopoietic failure, neutropenia | Knockout mice, CRISPR screens |
| SOX17 | Hematopoietic development defects | iPSC-derived hemogenic endothelium |
Leukemia and Hematopoietic Malignancies
Dysregulation of EHT-related genes is associated with leukemia. For example, RUNX1, a master regulator of EHT, is frequently mutated in acute myeloid leukemia and familial platelet disorder with predisposition to myeloid malignancy. The developmental programs hijacked by leukemic stem cells may resemble EHT, making this process a target for therapeutic intervention.
Bone Marrow Fibrosis and Hematopoietic Failure
Endothelial-to-mesenchymal transition (EndoMT), a process related to but distinct from EHT, contributes to bone marrow fibrosis and impairs hematopoietic reconstitution. Robo4 suppresses EndoMT and improves hematopoietic reconstitution, suggesting that modulating endothelial plasticity could treat bone marrow failure. Defects in EHT itself can lead to hematopoietic stem cell deficiencies.
Cardiac Fibrosis
EndoMT contributes to cardiac fibrosis, a pathological process distinct from EHT. While EHT is a developmental process, EndoMT in the heart leads to fibrosis after injury. Understanding the differences between these processes is important for developing targeted therapies.
From endothelial to hematopoietic transition-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate EHT? | CRISPR knockout in iPSC-derived hemogenic endothelium |
| What is the role of a specific point mutation in EHT? | Point mutation knock-in in mouse AGM or iPSCs |
| How does a tagged protein behave during EHT? | Tagged knock-in (e.g., GFP) in zebrafish or mouse |
| Does overexpression of gene Y enhance HSC generation? | Overexpression in iPSC-derived endothelial cells |
| What is the effect of a gene fusion on EHT? | Knock-in of fusion gene in human iPSCs |
| Can a drug modulate EHT? | Small molecule screening in iPSC-derived EHT cultures |
How to Study the endothelial to hematopoietic transition Process
| Method | What It Measures | Typical Application |
|---|---|---|
| RNA-seq | Gene expression changes | Identify regulators of EHT |
| CRISPR screen | Gene function on a genome-wide scale | Discover novel EHT regulators |
| Lineage tracing | Cell fate and origin | Distinguish EHT from EndoMT |
| Live imaging | Cell behavior and dynamics | Visualize delamination during EHT |
| Flow cytometry | Cell surface marker expression | Isolate HSCs derived from EHT |
| Proteomics | Protein expression and modifications | Study N-glycome regulation of EHT |
| Single-cell RNA-seq | Heterogeneity of cell states | Map EHT trajectory |
| In vitro iPSC differentiation | HSC generation from iPSCs | Model human EHT |
Transcriptomic Profiling (RNA-seq)
RNA sequencing of hemogenic endothelial cells and nascent HSCs during EHT can identify gene expression changes and regulatory networks. This method has been used to define the transcriptional landscape of EHT in mouse and human models.
CRISPR Screens
Genome-wide CRISPR knockout or activation screens in iPSC-derived EHT cultures can identify novel regulators of the transition. Such screens have the power to uncover genes that are essential for HSC generation.
Lineage Tracing
Lineage tracing in mouse models, using inducible Cre recombinase under endothelial-specific promoters, can track the fate of hemogenic endothelial cells during EHT. This approach has been used to distinguish EHT from EndoMT.
Imaging and Live-Cell Microscopy
Live imaging of zebrafish or mouse embryos can visualize the delamination of hemogenic endothelial cells in real time. This method provides spatial and temporal resolution of EHT.
How CRISPR Can Be Used to Study GO:0098508 endothelial to hematopoietic transition
Knockout
CRISPR knockout of candidate genes in iPSC-derived hemogenic endothelial cells or mouse models can determine whether a gene is required for EHT. For example, knockout of RUNX1 blocks EHT, confirming its essential role. Large-scale knockout screens can identify novel regulators.
Point Mutation
Introducing specific point mutations associated with human disease into EHT model systems can reveal how these mutations affect the transition. For instance, point mutations in RUNX1 found in leukemia can be knocked into iPSCs to study their impact on EHT.
Knock-in
Knock-in of reporter genes (e.g., GFP) or epitope tags into endogenous loci allows visualization and tracking of proteins during EHT. This approach can be used to monitor the expression of key transcription factors like RUNX1 in real time.
Overexpression
Overexpression of candidate genes in endothelial cells or iPSCs can test whether a gene is sufficient to promote EHT. For example, overexpression of Robo4 suppresses EndoMT and improves hematopoietic reconstitution, suggesting a protective role.
How EDITGENE Supports endothelial to hematopoietic transition Research
Researchers studying endothelial to hematopoietic transition-related genes often need to determine whether a candidate gene is causally involved in the process, and CRISPR-based models provide a robust way to test this. EDITGENE offers a comprehensive suite of services to support such studies, from knockout to overexpression and library screening.
Contact EDITGENE today to design your custom CRISPR model for endothelial to hematopoietic transition research.
Frequently Asked Questions About endothelial to hematopoietic transition
What is endothelial to hematopoietic transition?
Endothelial to hematopoietic transition (EHT) is the biological process where hemogenic endothelial cells generate hematopoietic stem cells through tight-junction dissolution, loss of cell polarity, and delamination from the endothelium, as defined by GO:0098508.
What genes are involved in endothelial to hematopoietic transition?
Key genes include RUNX1, NOTCH1, ROBO4, GFI1, TAL1, LMO2, ERG, FLI1, and SOX17, among others.
What is the role of Notch signaling in EHT?
Notch signaling is required for the specification of hemogenic endothelium and regulates the transition; its inhibition impairs EHT.
How is EHT regulated by glycosylation?
The N-glycome, the collection of N-linked glycans, regulates EHT efficiency, affecting the transition at multiple steps.
What is the difference between EHT and EndoMT?
EHT generates hematopoietic stem cells from endothelium, while EndoMT is a related but distinct process that contributes to fibrosis in heart and bone marrow.
What model systems are used to study EHT?
Common models include mouse aorta-gonad-mesonephros (AGM) region, zebrafish embryos, and human induced pluripotent stem cell (iPSC)-derived hemogenic endothelium.
How can CRISPR be used to study EHT?
CRISPR knockout, point mutation, knock-in, and overexpression can be used to test gene function in EHT models, and CRISPR screens can identify novel regulators.
What diseases are associated with EHT defects?
Defects in EHT are linked to hematopoietic failure, leukemia, and bone marrow fibrosis, while related EndoMT contributes to cardiac fibrosis.
What is the role of RUNX1 in EHT?
RUNX1 is a master transcription factor essential for EHT; its knockout blocks the transition, and mutations are found in leukemia.
How does Robo4 affect EHT?
Robo4 suppresses endothelial-to-mesenchymal transition and improves hematopoietic reconstitution, suggesting it maintains endothelial identity during EHT.
Conclusion
Endothelial to hematopoietic transition (GO:0098508) is a fundamental developmental process that generates hematopoietic stem cells from hemogenic endothelial cells. Its regulation by Notch signaling, N-glycosylation, and stage-specific cytokines underscores the complexity of this transition. Understanding EHT has broad implications for regenerative medicine, leukemia research, and bone marrow failure. With advanced CRISPR tools and model systems, researchers can now dissect the molecular mechanisms of EHT with unprecedented precision.
References
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- 3. Wellington R et al.. 2025. Developmental regulation of endothelial-to-hematopoietic transition from induced pluripotent stem cells.. Stem Cell Reports 20(10):102641 PMID: 40972587
- 4. Cao J et al.. 2023. Reassessing endothelial-to-mesenchymal transition in mouse bone marrow: insights from lineage tracing models.. Nat Commun 14(1):8461 PMID: 38123537
- 5. Guo W et al.. 2024. Notch signaling regulates macrophage-mediated inflammation in metabolic dysfunction-associated steatotic liver disease.. Immunity 57(10):2310-2327.e6 PMID: 39317200
- 6. Morino-Koga S et al.. 2024. Transition of signal requirement in hematopoietic stem cell development from hemogenic endothelial cells.. Proc Natl Acad Sci U S A 121(31):e2404193121 PMID: 39042698
- 7. Adzraku SY et al.. 2024. Endothelial Robo4 suppresses endothelial-to-mesenchymal transition induced by irradiation and improves hematopoietic reconstitution.. Cell Death Dis 15(2):159 PMID: 38383474
- 8. Kasper DM et al.. 2020. The N-glycome regulates the endothelial-to-hematopoietic transition.. Science 370(6521):1186-1191 PMID: 33273096
