GO:0061028 establishment of endothelial barrier: Barrier Assembly, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0061028 (establishment of endothelial barrier) describes the biological process that creates a selective barrier between endothelial cell layers in tissues such as brain, lung and intestine, controlling water and solute passage.
• The blood-brain barrier (BBB) is the best-characterized example, where brain endothelial cells, pericytes and astrocyte end-feet cooperate to form a tight, specialized interface.
• Key molecular players include tight junction proteins, MFSD2A, C3aR, and vitronectin-integrin signaling between pericytes and endothelial cells.
• Loss of endothelial barrier integrity contributes to neuroinflammation, aging-related BBB permeability, lung injury, and systemic infections such as syphilis.
• In vitro BBB models, such as the hCMEC/D3 cell line, are essential tools for studying barrier establishment and drug permeability.
• CRISPR-based knockout, knock-in and overexpression models enable causal testing of barrier-related genes in endothelial cells.
Description
The establishment of endothelial barrier (GO:0061028) is a fundamental biological process that creates a selective interface between endothelial cell layers, controlling the passage of water and solutes to maintain distinct fluid and solute compartments. This process is critical in organs such as the brain, lung and intestine, where barrier integrity is essential for normal physiology. The blood-brain barrier (BBB) represents the most studied example, where brain endothelial cells form tight junctions and interact with pericytes and astrocytes to restrict paracellular and transcellular transport. Disruption of endothelial barriers is associated with a wide range of pathologies, including neuroinflammation, aging, lung injury, and infectious diseases. Understanding the molecular mechanisms that establish and maintain these barriers is therefore of great interest for both basic research and therapeutic development. This article provides a comprehensive overview of GO:0061028, covering its definition, key genes, regulatory mechanisms, disease relevance, and experimental approaches including CRISPR-based models.
establishment of endothelial barrier At A Glance
| GO ID | GO:0061028 |
|---|---|
| GO term | establishment of endothelial barrier |
| Ontology | biological_process |
| Synonym | None |
| Major function | Selective control of water and solute passage between endothelial cell layers |
| Tissue examples | Brain, lung, intestine |
| Key cell types | Endothelial cells, pericytes, astrocytes |
| Related processes | Tight junction assembly, transcytosis regulation, vascular permeability |
What Is GO:0061028?
GO:0061028, establishment of endothelial barrier, is defined as the biological process that creates a barrier between endothelial cell layers, such as those in the brain, lung or intestine, to exert specific and selective control over the passage of water and solutes, thus allowing formation and maintenance of compartments that differ in fluid and solute composition. In simpler terms, it is the process by which endothelial cells build a tight, selective fence that separates different fluid compartments in the body.
Why Is establishment of endothelial barrier Important in Cell Biology?
The establishment of endothelial barrier is essential for maintaining tissue homeostasis and protecting organs from harmful substances. In the brain, the BBB shields neurons from toxins and pathogens while supplying nutrients. In the lung, endothelial barrier integrity prevents edema and inflammation. Disruption of this process is a hallmark of many diseases, including neurodegeneration, stroke, and infections. Studying GO:0061028 helps researchers understand disease mechanisms and develop therapies that restore barrier function.
• Maintains brain homeostasis by forming the blood-brain barrier.
• Prevents lung edema by controlling fluid balance in pulmonary endothelium.
• Regulates immune cell infiltration and inflammation.
• Its dysfunction is linked to aging-related cognitive decline.
• Plays a role in infectious diseases such as syphilis.
• Provides a target for drug delivery across the BBB.
• Involved in corneal endothelial barrier function.
• Critical for pericyte-endothelial communication.
• MFSD2A regulates transcytosis to maintain BBB integrity.
• C3aR activation increases permeability during aging.
What Happens During establishment of endothelial barrier?
Endothelial cell polarization and junction formation
In simple terms: Endothelial cells organize themselves and form tight connections with each other.
The establishment of an endothelial barrier begins with the polarization of endothelial cells and the formation of intercellular junctions. Brain endothelial cells, for example, express tight junction proteins that seal the paracellular space, a process that is critical for BBB function. These junctions are dynamic and regulated by signaling pathways that respond to the local environment.
Pericyte-endothelial crosstalk
In simple terms: Supporting cells called pericytes communicate with endothelial cells to strengthen the barrier.
Pericytes play a crucial role in barrier establishment by signaling to endothelial cells. Ayloo et al. demonstrated that pericyte-to-endothelial cell signaling via vitronectin-integrin regulates blood-CNS barrier function. This crosstalk is essential for the proper formation and maintenance of the barrier.
Regulation of transcytosis
In simple terms: Cells control the movement of substances across the barrier by regulating vesicle transport.
Transcytosis is a major route for molecular transport across endothelial barriers. MFSD2A is a key regulator of transcytosis in the BBB; its loss leads to increased transcytosis and barrier breakdown. This highlights the importance of transcytosis suppression in establishing a tight barrier.
Inflammatory signaling and barrier permeability
In simple terms: Inflammation can weaken the barrier by activating specific receptors.
Inflammatory mediators can disrupt endothelial barriers. Propson et al. showed that endothelial C3a receptor mediates vascular inflammation and BBB permeability during aging. This indicates that immune signaling pathways are integral to barrier regulation and dysfunction.
Key Genes Involved in GO:0061028 establishment of endothelial barrier
The following genes and proteins are critically involved in the establishment and regulation of endothelial barriers.
| Gene | Major Role | Research Relevance |
|---|---|---|
| MFSD2A | Suppresses transcytosis to maintain BBB integrity | Knockout leads to BBB breakdown |
| C3AR1 | Mediates vascular inflammation and permeability | Inhibition reduces aging-related BBB leakage |
| VTN | Extracellular matrix protein involved in pericyte-endothelial signaling | Regulates blood-CNS barrier via integrin binding |
| ITGAV | Integrin subunit mediating vitronectin signaling | Pericyte-to-endothelial communication |
| ITGB1 | Integrin subunit mediating vitronectin signaling | Pericyte-to-endothelial communication |
| CLDN5 | Tight junction protein | Essential for BBB tightness |
| OCLN | Tight junction protein | Barrier formation |
| TJP1 | Tight junction adaptor protein | Links tight junctions to cytoskeleton |
| CDH5 | Adherens junction protein | Endothelial cell-cell adhesion |
| PECAM1 | Adhesion molecule | Leukocyte transmigration and barrier regulation |
| VEGFA | Growth factor regulating permeability | Can disrupt barrier under pathological conditions |
| ANGPT2 | Angiopoietin that destabilizes junctions | Increases permeability in inflammation |
| TNF | Pro-inflammatory cytokine | Disrupts barrier via oxidative stress |
| IL1B | Pro-inflammatory cytokine | Induces barrier dysfunction |
| NOS3 | Endothelial nitric oxide synthase | Regulates vascular tone and permeability |
| CD46 | Complement regulatory protein | May modulate barrier in infections |
How Is establishment of endothelial barrier Regulated?
The establishment of endothelial barrier is regulated by multiple signaling pathways. Inflammatory cytokines such as TNF and IL1B can increase permeability through oxidative stress and junctional remodeling. The complement system, via C3aR, promotes vascular inflammation and barrier leakage during aging. Pericyte-derived vitronectin signals through integrins to maintain barrier integrity. Additionally, MFSD2A suppresses transcytosis, and its downregulation leads to barrier breakdown. These regulatory mechanisms are potential targets for therapeutic intervention.
establishment of endothelial barrier and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| C3AR1 | Aging-related BBB permeability | Knockout mouse, endothelial cell line |
| MFSD2A | BBB breakdown, neurodegeneration | Knockout mouse, hCMEC/D3 cells |
| VTN | Blood-CNS barrier dysfunction | Pericyte-specific knockout |
| CLDN5 | Barrier loss in inflammation | Endothelial-specific knockout |
| CD46 | Syphilis-associated endothelial dysfunction | In vitro infection model |
Blood-brain barrier dysfunction in aging and neurodegeneration
Aging is associated with increased BBB permeability, partly mediated by endothelial C3a receptor activation. This dysfunction contributes to neuroinflammation and cognitive decline. MFSD2A loss also impairs BBB integrity, linking lipid metabolism to barrier function.
Lung injury and endothelial barrier disruption
Oxidized phospholipids can disrupt pulmonary endothelial barriers, leading to lung injury and edema. Understanding these mechanisms is crucial for developing therapies for acute respiratory distress syndrome.
Infectious diseases and endothelial dysfunction
Syphilis can cause endothelial dysfunction, including barrier disruption, contributing to its pathogenesis. This highlights the importance of endothelial barriers in infectious diseases.
Corneal endothelial barrier and eye disease
Corneal endothelial barrier function is essential for corneal transparency. Finite element analysis of Y-junctions provides insights into barrier mechanics. Disruption can lead to corneal edema and vision loss.
From establishment of endothelial barrier-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X regulate barrier integrity? | CRISPR knockout in hCMEC/D3 cells |
| Does a point mutation in gene Y affect barrier function? | CRISPR point mutation knock-in |
| Can overexpression of gene Z strengthen the barrier? | Lentiviral overexpression in endothelial cells |
| What is the role of pericyte-endothelial signaling? | Co-culture models with pericytes |
| How does inflammation affect barrier permeability? | TNF treatment in vitro |
| Can we screen for novel barrier regulators? | CRISPR library screening |
How to Study the establishment of endothelial barrier Process
| Method | What It Measures | Typical Application |
|---|---|---|
| TEER | Barrier tightness | In vitro BBB models |
| Permeability assay | Solute flux | Drug permeability studies |
| Immunofluorescence | Junction protein localization | Barrier formation |
| Western blot | Protein expression | Target validation |
| CRISPR knockout | Gene function | Causal testing |
| RNA-seq | Transcriptional changes | Pathway analysis |
| Proteomics | Protein abundance | Barrier composition |
In vitro BBB models
The hCMEC/D3 cell line is a widely used human brain endothelial cell model that exhibits BBB properties. Helms et al. provide guidelines for using such models to study barrier establishment.
Transendothelial electrical resistance (TEER)
TEER measures barrier tightness in real-time and is a standard assay for endothelial barrier function.
Permeability assays
Fluorescent tracer permeability assays quantify paracellular and transcellular transport across endothelial monolayers.
Imaging of junctional proteins
Immunofluorescence and confocal microscopy visualize tight junction proteins like CLDN5 and OCLN to assess barrier formation.
How CRISPR Can Be Used to Study GO:0061028 establishment of endothelial barrier
Knockout
CRISPR knockout of barrier-related genes such as MFSD2A or C3AR1 in endothelial cells can reveal their causal role in barrier establishment.
Point Mutation
Introducing point mutations in tight junction genes can mimic disease-associated variants and test their impact on barrier function.
Knock-in
Knock-in of fluorescent tags or reporter genes allows live imaging of barrier dynamics and protein localization.
Overexpression
Overexpression of protective genes, such as MFSD2A, can enhance barrier integrity and serve as a therapeutic strategy.
How EDITGENE Supports establishment of endothelial barrier Research
Researchers studying establishment of endothelial barrier-related genes often need to determine whether a candidate gene is causally involved in barrier formation or maintenance. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research.
Contact EDITGENE today to design your custom CRISPR model for establishment of endothelial barrier research.
Frequently Asked Questions About establishment of endothelial barrier
What is GO:0061028?
GO:0061028 is the Gene Ontology term for establishment of endothelial barrier, the process that creates a selective barrier between endothelial cell layers.
What genes are involved in establishment of endothelial barrier?
Key genes include MFSD2A, C3AR1, VTN, CLDN5, and OCLN.
How is the blood-brain barrier established?
The BBB is established through tight junction formation, pericyte-endothelial crosstalk, and suppression of transcytosis.
What diseases are linked to endothelial barrier dysfunction?
Aging-related neurodegeneration, lung injury, and infectious diseases like syphilis.
What cell models are used to study endothelial barrier?
The hCMEC/D3 cell line and primary brain endothelial cells are commonly used.
How does MFSD2A regulate the blood-brain barrier?
MFSD2A suppresses transcytosis; its loss increases permeability and barrier breakdown.
What is the role of pericytes in endothelial barrier?
Pericytes signal to endothelial cells via vitronectin-integrin to maintain barrier integrity.
How can CRISPR be used to study endothelial barrier genes?
CRISPR knockout, knock-in, and overexpression can test gene function in barrier establishment.
What is TEER and how is it used?
TEER measures transendothelial electrical resistance, indicating barrier tightness in vitro.
What is the role of C3aR in barrier permeability?
C3aR mediates vascular inflammation and increases BBB permeability during aging.
Conclusion
The establishment of endothelial barrier (GO:0061028) is a vital biological process that maintains tissue homeostasis and protects organs from harmful substances. Dysregulation of this process contributes to numerous diseases, making it a key area of research. Advances in CRISPR-based models and in vitro systems continue to unravel the molecular mechanisms underlying barrier formation, offering hope for novel therapeutic strategies.
References
- 1. Weksler BB et al.. 2005. Blood-brain barrier-specific properties of a human adult brain endothelial cell line.. FASEB J 19(13):1872-4 PMID: 16141364
- 2. Helms HC et al.. 2016. In vitro models of the blood-brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use.. J Cereb Blood Flow Metab 36(5):862-90 PMID: 26868179
- 3. Ayloo S et al.. 2022. Pericyte-to-endothelial cell signaling via vitronectin-integrin regulates blood-CNS barrier.. Neuron 110(10):1641-1655.e6 PMID: 35294899
- 4. Propson NE et al.. 2021. Endothelial C3a receptor mediates vascular inflammation and blood-brain barrier permeability during aging.. J Clin Invest 131(1) PMID: 32990682
- 5. Ben-Zvi A et al.. 2014. Mfsd2a is critical for the formation and function of the blood-brain barrier.. Nature 509(7501):507-11 PMID: 24828040
- 6. Karki P et al.. 2021. Oxidized Phospholipids in Control of Endothelial Barrier Function: Mechanisms and Implication in Lung Injury.. Front Endocrinol (Lausanne) 12:794437 PMID: 34887839
- 7. Liu Z et al.. 2024. Endothelial dysfunction of syphilis: Pathogenesis.. J Eur Acad Dermatol Venereol 38(8):1478-1490 PMID: 38376088
- 8. Li D et al.. 2025. Assessment of Corneal Endothelial Barrier Function Based on "Y-Junctions": A Finite Element Analysis.. Invest Ophthalmol Vis Sci 66(5):33 PMID: 40408094
