GO:2000545 negative regulation of endothelial cell chemotaxis to fibroblast growth factor: Signaling Brake, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:2000545 describes any process that stops, prevents or reduces endothelial cell chemotaxis toward fibroblast growth factor (FGF), a key step in angiogenesis.
• FGF-2-driven endothelial migration depends on Src activation through the adaptor Fes and on focal adhesion turnover.
• Inhibition of FGF-2 chemotaxis can be achieved by blocking receptor tyrosine kinase activity, for example with gefitinib, which downregulates Fes activity.
• The chemokine CXCL13 (BCA-1) directly inhibits FGF-2 effects on endothelial cells, providing a physiological example of negative regulation.
• Axl tyrosine kinase receptor activation counteracts VEGF receptor 2-mediated endothelial activation, illustrating cross-talk between pro- and anti-migratory signals.
• Loss of negative regulation of FGF-driven chemotaxis is relevant to tumor angiogenesis, where excessive endothelial sprouting supports tumor growth.
Description
Endothelial cell chemotaxis toward fibroblast growth factor (FGF) is a central event in angiogenesis, the process by which new blood vessels sprout from existing ones. The Gene Ontology term GO:2000545, negative regulation of endothelial cell chemotaxis to fibroblast growth factor, captures the biological processes that stop, prevent or reduce the frequency, rate or extent of this directed migration. Because FGF-2 is a potent endothelial mitogen and chemoattractant, tight negative control of this response is essential to avoid uncontrolled vessel formation. Understanding GO:2000545 therefore matters for researchers studying vascular biology, tumor angiogenesis and tissue repair. Mechanistically, FGF-2 binding to its receptor triggers intracellular signaling that includes Src activation through the adaptor protein Fes, which in turn regulates focal adhesion disassembly and cell movement. Negative regulation of this chemotactic response can occur at multiple levels, including receptor tyrosine kinase inhibition, chemokine-mediated interference, and modulation of focal adhesion dynamics. For example, the chemokine CXCL13 (BCA-1) inhibits FGF-2 effects on endothelial cells, providing a natural brake on FGF-driven migration. Similarly, Axl tyrosine kinase receptor activation can inhibit VEGF receptor 2-mediated endothelial cell activation, showing that negative regulation often involves cross-talk between different pro-angiogenic pathways. For biomedical researchers, GO:2000545 provides a framework to annotate genes and pathways that restrain FGF-induced endothelial chemotaxis. This is important because excessive or insufficient negative regulation can contribute to pathological angiogenesis, including tumor vascularization. Studying this term helps identify molecular targets that could be manipulated to either promote or inhibit blood vessel growth in disease settings.
negative regulation of endothelial cell chemotaxis to fibroblast growth factor At A Glance
| GO ID | GO:2000545 |
|---|---|
| GO term | negative regulation of endothelial cell chemotaxis to fibroblast growth factor |
| Ontology | biological_process |
| Synonym | none |
| Major function | Negative regulation of endothelial cell directed migration toward FGF |
| Related process | Angiogenesis, endothelial cell migration, FGF signaling |
| Key signaling nodes | FGF receptor, Src, Fes, focal adhesions, CXCL13, Axl |
| Disease relevance | Tumor angiogenesis, vascular disorders |
| Research methods | Chemotaxis assays, CRISPR knockout, phosphoproteomics, live imaging |
What Is GO:2000545?
GO:2000545 is a biological process term defined as any process that stops, prevents or reduces the frequency, rate or extent of endothelial cell chemotaxis to fibroblast growth factor. In other words, it covers all molecular and cellular events that negatively regulate the directed movement of endothelial cells along a gradient of FGF. This includes inhibition of FGF receptor signaling, interference with downstream Src/Fes activation, and disruption of focal adhesion turnover required for migration.
Why Is negative regulation of endothelial cell chemotaxis to fibroblast growth factor Important in Cell Biology?
GO:2000545 is important because FGF-driven endothelial chemotaxis is a rate-limiting step in angiogenesis, and its negative regulation prevents excessive or inappropriate blood vessel formation. Dysregulation of this brake can contribute to tumor angiogenesis, where cancer cells secrete FGF-2 and other pro-angiogenic factors to sustain growth. Conversely, understanding how to enhance negative regulation could provide therapeutic strategies to limit pathological angiogenesis. The term also highlights the cross-talk between chemokine and growth factor signaling in endothelial cells, as exemplified by CXCL13 inhibition of FGF-2 effects.
• Controls angiogenesis by limiting endothelial cell migration toward FGF gradients.
• Prevents uncontrolled vascular sprouting in tumors and ischemic tissues.
• Involves cross-talk between FGF receptor, Src/Fes, and focal adhesion signaling.
• Provides a mechanism for chemokines such as CXCL13 to oppose FGF-2 activity.
• Relevant to anti-angiogenic therapy, as blocking FGF-driven chemotaxis can starve tumors.
• Axl receptor activation can negatively regulate endothelial activation by VEGF receptor 2.
• Helps explain why some anti-angiogenic treatments fail due to compensatory FGF signaling.
• Offers targets for CRISPR screening to identify novel negative regulators of endothelial migration.
• Important for tissue engineering, where controlled vascularization is desired.
• Links to developmental processes such as embryonic stem cell differentiation into fibroblast-like cells.
What Happens During negative regulation of endothelial cell chemotaxis to fibroblast growth factor?
Initiation of FGF-2 signaling and chemotaxis
In simple terms: FGF-2 acts like a green light for endothelial cell movement.
Fibroblast growth factor-2 (FGF-2) binds to FGF receptors on endothelial cells, triggering intracellular signaling that promotes directed migration. This involves activation of Src through the adaptor protein Fes, which regulates focal adhesion disassembly and allows cells to move. Focal adhesion formation and turnover are critical for endothelial cell migration and morphogenesis. Negative regulation of this process begins when inhibitory signals intercept this pro-migratory cascade.
Receptor-level inhibition
In simple terms: Blocking the receptor is like cutting the phone line before the message gets through.
Negative regulation can occur at the level of the FGF receptor or related tyrosine kinases. For example, gefitinib, an EGFR tyrosine kinase inhibitor, inhibits endothelial cell chemotaxis toward FGF-2 by downregulating Fes activity. This demonstrates that pharmacological or cellular inhibition of receptor tyrosine kinase signaling can stop FGF-driven chemotaxis. Similarly, Axl tyrosine kinase receptor activation inhibits VEGF receptor 2-mediated endothelial cell activation, showing that receptor cross-talk can negatively regulate pro-angiogenic responses.
Chemokine-mediated interference
In simple terms: Chemokines can act as stop signs for FGF-driven movement.
The chemokine CXCL13 (BCA-1) inhibits FGF-2 effects on endothelial cells, providing a physiological example of negative regulation. This suggests that chemokine gradients can override or dampen FGF-induced chemotaxis. The relative distribution and biological characterization of chemokines such as CXCL4L1 isoforms in platelets further highlight the complexity of chemokine-mediated regulation in vascular biology.
Downstream modulation of focal adhesions and cytoskeleton
In simple terms: Even if the signal gets through, the cell's skeleton can be locked to stop movement.
Focal adhesion disassembly is required for endothelial cell migration. FGF-2 induces Src activation through Fes, which regulates focal adhesion disassembly. Negative regulation of chemotaxis can therefore occur by stabilizing focal adhesions or preventing their turnover. The role of focal adhesion formation in migration and morphogenesis of endothelial cells underscores this as a key control point.
Integration with other signaling pathways
In simple terms: Different signals talk to each other to decide whether the cell should move.
Negative regulation of FGF-driven chemotaxis does not occur in isolation. Cross-talk with VEGF signaling, as shown by Axl-mediated inhibition of VEGFR2 activation, can modulate endothelial responses. Additionally, p73 overexpression increases VEGF and reduces thrombospondin-1 production, implicating p73 in the regulation of angiogenic balance. These interactions illustrate that GO:2000545 integrates multiple signaling inputs to fine-tune endothelial cell migration.
Key Genes Involved in GO:2000545 negative regulation of endothelial cell chemotaxis to fibroblast growth factor
The following genes and proteins are experimentally implicated in the negative regulation of endothelial cell chemotaxis to fibroblast growth factor or in the underlying FGF signaling pathway.
| Gene | Major Role | Research Relevance |
|---|---|---|
| FGF2 | Ligand that stimulates endothelial chemotaxis | Primary trigger of the process being negatively regulated |
| FGFR1 | Receptor for FGF-2 | Mediates pro-migratory signaling; target for inhibition |
| SRC | Kinase activated downstream of FGF-2 | Regulates focal adhesion disassembly and migration |
| FES | Adaptor/kinase linking FGF-2 to Src | Downregulation inhibits chemotaxis |
| CXCL13 | Chemokine that inhibits FGF-2 effects | Physiological negative regulator |
| AXL | Tyrosine kinase receptor | Inhibits VEGFR2-mediated endothelial activation |
| VEGFA | Pro-angiogenic growth factor | Cross-talk with FGF signaling |
| THBS1 | Thrombospondin-1, anti-angiogenic | Reduced by p73 overexpression |
| TP73 | p73 tumor suppressor | Overexpression increases VEGF and reduces THBS1 |
| CXCL4L1 | Chemokine isoform | Biological characterization in platelets |
| EGFR | Receptor tyrosine kinase | Gefitinib target that downregulates Fes |
| PTK2 | Focal adhesion kinase | Focal adhesion turnover |
| ITGB1 | Integrin beta 1 | Focal adhesion formation |
| PXN | Paxillin | Focal adhesion component |
| VCL | Vinculin | Focal adhesion component |
| RAC1 | Rho GTPase | Cytoskeletal dynamics during migration |
| CDC42 | Rho GTPase | Cytoskeletal dynamics during migration |
How Is negative regulation of endothelial cell chemotaxis to fibroblast growth factor Regulated?
The negative regulation of endothelial cell chemotaxis to FGF is itself controlled by multiple signaling inputs. Receptor tyrosine kinase inhibitors such as gefitinib can downregulate Fes activity, thereby reducing chemotaxis. Chemokines like CXCL13 directly inhibit FGF-2 effects. Cross-talk with VEGF signaling via Axl can also modulate endothelial activation. Additionally, p73 overexpression alters the balance of pro- and anti-angiogenic factors by increasing VEGF and reducing thrombospondin-1. These layers of regulation ensure that endothelial cell migration is tightly controlled in response to environmental cues.
negative regulation of endothelial cell chemotaxis to fibroblast growth factor and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| FGF2 | Tumor angiogenesis | Endothelial cell chemotaxis assay with FGF-2 gradient |
| CXCL13 | Inflammatory angiogenesis | CXCL13 knockout endothelial cells |
| AXL | Vascular normalization | Axl overexpression in endothelial cells |
| TP73 | Cancer angiogenesis | p73 knockout or overexpression models |
| FES | Anti-angiogenic therapy resistance | Fes knockdown in HUVECs |
Tumor angiogenesis
Excessive FGF-driven endothelial chemotaxis contributes to tumor angiogenesis. Loss of negative regulation can lead to uncontrolled vessel formation that supports tumor growth. p73 overexpression increases VEGF and reduces thrombospondin-1, promoting an angiogenic environment. Targeting negative regulators of FGF chemotaxis could therefore inhibit tumor vascularization.
Vascular disorders
Imbalances in negative regulation of FGF chemotaxis may contribute to vascular disorders characterized by abnormal vessel growth or regression. The interplay between FGF and VEGF signaling, as exemplified by Axl-mediated inhibition of VEGFR2, highlights potential therapeutic targets.
Inflammation and chemokine regulation
Chemokines such as CXCL13 and CXCL4L1 modulate endothelial responses to FGF-2. Dysregulation of these chemokine networks could affect inflammatory angiogenesis and vascular remodeling.
From negative regulation of endothelial cell chemotaxis to fibroblast growth factor-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does gene X negatively regulate FGF-induced chemotaxis? | CRISPR knockout of gene X in endothelial cells followed by chemotaxis assay |
| Does a point mutation in gene X affect its inhibitory function? | Point-mutation knock-in via CRISPR |
| Does overexpression of gene X suppress chemotaxis? | CRISPRa or lentiviral overexpression |
| Where is gene X localized during chemotaxis? | Tagged knock-in with fluorescent protein |
| Which genes are required for negative regulation? | Genome-wide CRISPR library screening |
| What signaling pathways are altered? | Phosphoproteomics and RNA-seq after gene editing |
How to Study the negative regulation of endothelial cell chemotaxis to fibroblast growth factor Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Transwell chemotaxis assay | Number of migrated cells | Quantify negative regulation of FGF chemotaxis |
| Microfluidic gradient assay | Directional migration | Live imaging of chemotaxis |
| CRISPR knockout screen | Gene requirement | Identify novel negative regulators |
| Phosphoproteomics | Phosphorylation changes | Map signaling downstream of FGF |
| Immunofluorescence | Focal adhesion number/size | Assess focal adhesion dynamics |
| RNA-seq | Transcriptional changes | Identify pathways altered by gene editing |
| Western blot | Protein expression/activation | Validate signaling changes |
Chemotaxis assays
Boyden chamber or microfluidic chemotaxis assays are used to measure endothelial cell migration toward FGF-2 gradients. These assays can quantify the effect of genetic perturbations on negative regulation.
CRISPR screening
Genome-wide CRISPR knockout or activation screens can identify novel negative regulators of FGF-driven chemotaxis. Hits can be validated in secondary assays.
Phosphoproteomics
Mass spectrometry-based phosphoproteomics can reveal changes in signaling pathways, such as Src and Fes phosphorylation, following perturbation of candidate genes.
Live-cell imaging
Time-lapse microscopy of fluorescently tagged focal adhesion proteins (e.g., paxillin, vinculin) allows visualization of focal adhesion dynamics during chemotaxis.
How CRISPR Can Be Used to Study GO:2000545 negative regulation of endothelial cell chemotaxis to fibroblast growth factor
Knockout
CRISPR knockout of candidate negative regulators (e.g., CXCL13, AXL) in endothelial cells can test whether loss of function increases FGF-driven chemotaxis. This approach directly assesses the role of a gene in GO:2000545.
Point Mutation
Introducing point mutations in genes such as FES or SRC can dissect specific phosphorylation sites required for negative regulation. This helps distinguish between catalytic and adaptor functions.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) into endogenous loci allows real-time tracking of proteins during chemotaxis. Tagged knock-in of focal adhesion proteins can reveal their dynamics.
Overexpression
CRISPR activation or lentiviral overexpression of suspected negative regulators (e.g., CXCL13, AXL) can confirm their ability to suppress FGF-induced chemotaxis.
How EDITGENE Supports negative regulation of endothelial cell chemotaxis to fibroblast growth factor Research
Researchers studying negative regulation of endothelial cell chemotaxis to fibroblast growth factor-related genes often need to determine whether a candidate gene is causally involved in restraining FGF-driven migration. EDITGENE provides a comprehensive suite of CRISPR services to enable such investigations, from knockout to overexpression and library screening.
Contact EDITGENE today to design your custom CRISPR model for negative regulation of endothelial cell chemotaxis to fibroblast growth factor research.
Frequently Asked Questions About negative regulation of endothelial cell chemotaxis to fibroblast growth factor
What is GO:2000545?
GO:2000545 is a Gene Ontology biological process term defined as any process that stops, prevents or reduces the frequency, rate or extent of endothelial cell chemotaxis to fibroblast growth factor.
What genes are involved in negative regulation of endothelial cell chemotaxis to FGF?
Key genes include CXCL13, AXL, FES, SRC, and FGF2 itself, as well as focal adhesion components like PTK2 and PXN.
How is FGF-driven endothelial chemotaxis inhibited?
It can be inhibited by receptor tyrosine kinase inhibitors like gefitinib, by chemokines such as CXCL13, or by cross-talk from Axl signaling.
What is the role of Fes in FGF chemotaxis?
Fes is an adaptor/kinase that links FGF-2 signaling to Src activation, which regulates focal adhesion disassembly and migration; downregulation of Fes inhibits chemotaxis.
Which diseases are associated with dysregulated FGF chemotaxis?
Tumor angiogenesis and vascular disorders are associated with excessive FGF-driven endothelial migration.
How can I study negative regulation of FGF chemotaxis in the lab?
Common methods include Transwell chemotaxis assays, CRISPR knockout screens, phosphoproteomics, and live-cell imaging of focal adhesions.
What is the role of CXCL13 in endothelial cells?
CXCL13 (BCA-1) inhibits FGF-2 effects on endothelial cells, acting as a negative regulator of chemotaxis.
Does Axl inhibit endothelial cell migration?
Axl tyrosine kinase receptor activation inhibits VEGF receptor 2-mediated endothelial cell activation, which can indirectly affect FGF-driven responses.
What CRISPR models are available for studying this process?
Knockout, point mutation, knock-in, and overexpression models can be generated for genes like CXCL13, AXL, FES, and SRC.
Why is negative regulation of FGF chemotaxis important for cancer?
It prevents excessive angiogenesis that supports tumor growth; loss of this regulation can promote tumor vascularization.
Conclusion
GO:2000545 represents a critical braking mechanism in angiogenesis, ensuring that endothelial cell migration toward FGF is tightly controlled. The interplay between FGF-2, Src/Fes signaling, chemokines like CXCL13, and receptor cross-talk defines a complex regulatory network. Understanding this process offers opportunities for therapeutic intervention in cancer and vascular diseases. EDITGENE provides the CRISPR tools needed to dissect these pathways and identify new targets.
References
- 1. Gallicchio M et al.. 2005. Inhibition of vascular endothelial growth factor receptor 2-mediated endothelial cell activation by Axl tyrosine kinase receptor.. Blood 105(5):1970-6 PMID: 15507525
- 2. Kanda S et al.. 2006. Fibroblast growth factor-2 induces the activation of Src through Fes, which regulates focal adhesion disassembly.. Exp Cell Res 312(16):3015-22 PMID: 16884713
- 3. Kanda S et al.. 2009. Inhibition of endothelial cell chemotaxis toward FGF-2 by gefitinib associates with downregulation of Fes activity.. Int J Oncol 35(6):1305-12 PMID: 19885553
- 4. Kanda S et al.. 2004. Role of focal adhesion formation in migration and morphogenesis of endothelial cells.. Cell Signal 16(11):1273-81 PMID: 15337526
- 5. Ruytinx P et al.. 2017. Relative distribution and biological characterization of CXCL4L1 isoforms in platelets from healthy donors.. Biochem Pharmacol 145:123-131 PMID: 28859966
- 6. Togo S et al.. 2011. Differentiation of embryonic stem cells into fibroblast-like cells in three-dimensional type I collagen gel cultures.. In Vitro Cell Dev Biol Anim 47(2):114-24 PMID: 21107747
- 7. Vikhanskaya F et al.. 2001. p73 Overexpression increases VEGF and reduces thrombospondin-1 production: implications for tumor angiogenesis.. Oncogene 20(50):7293-300 PMID: 11704858
- 8. Spinetti G et al.. 2001. The chemokine CXCL13 (BCA-1) inhibits FGF-2 effects on endothelial cells.. Biochem Biophys Res Commun 289(1):19-24 PMID: 11708770
