Target type: biologicalprocess
Any process that activates or increases the frequency, rate or extent of endothelial cell chemotaxis to fibroblast growth factor. [GOC:obol]
Positive regulation of endothelial cell chemotaxis to fibroblast growth factor (FGF) is a complex and tightly regulated process that plays a crucial role in angiogenesis, the formation of new blood vessels. It involves a series of molecular events that initiate, direct, and control the movement of endothelial cells, the cells that line blood vessels, towards FGF. Here's a detailed description of the process:
1. **FGF Binding and Receptor Activation:**
- FGFs, a family of signaling proteins, act as chemoattractants for endothelial cells.
- FGFs bind to their cognate receptors, known as fibroblast growth factor receptors (FGFRs), which are transmembrane tyrosine kinases present on the surface of endothelial cells.
- This binding activates the FGFRs, triggering a cascade of intracellular signaling events.
2. **Signal Transduction and Activation of Downstream Pathways:**
- Activation of FGFRs leads to the phosphorylation of intracellular signaling proteins, including the adaptor protein GRB2 and the guanine nucleotide exchange factor SOS.
- GRB2 and SOS activate the Ras protein, a small GTPase, which then activates a signaling cascade known as the Ras-MAPK pathway.
- The Ras-MAPK pathway involves a series of kinases, including Raf, MEK, and ERK, culminating in the phosphorylation and activation of transcription factors, such as Elk-1 and c-Fos.
3. **Gene Expression and Protein Production:**
- Activated transcription factors bind to specific DNA sequences in the promoter regions of genes that regulate endothelial cell chemotaxis.
- This binding stimulates the transcription of genes involved in cell motility, adhesion, and migration, including:
- **Integrins:** Cell adhesion molecules that mediate the interaction between endothelial cells and the extracellular matrix.
- **Chemokine receptors:** Receptors that bind to chemokines, chemoattractant proteins that guide endothelial cell migration.
- **Actin polymerization proteins:** Proteins that regulate the assembly and disassembly of the actin cytoskeleton, which provides the structural framework for cell movement.
- **Matrix metalloproteinases (MMPs):** Enzymes that degrade the extracellular matrix, allowing endothelial cells to migrate through tissues.
4. **Chemotaxis and Endothelial Cell Movement:**
- The expression of these genes leads to the production of proteins that facilitate endothelial cell chemotaxis.
- Integrins bind to the extracellular matrix, providing anchorage for endothelial cells.
- Chemokine receptors bind to chemokines, generating chemotactic gradients that direct endothelial cell movement.
- Actin polymerization drives the formation of protrusions, known as lamellipodia and filopodia, at the leading edge of the migrating endothelial cells.
- MMPs degrade the extracellular matrix, creating pathways for endothelial cells to move through tissues.
5. **Angiogenesis and Vascular Development:**
- The coordinated action of these molecular events enables endothelial cells to migrate towards FGF, forming new blood vessels in a process called angiogenesis.
- Angiogenesis is essential for tissue repair, wound healing, and embryonic development.
This intricate interplay of signaling pathways, gene expression, and protein activity ensures that endothelial cells respond to FGF in a highly coordinated and directed manner, facilitating their movement and contributing to the formation of new blood vessels.'
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Protein | Definition | Taxonomy |
---|---|---|
Fibroblast growth factor 2 | A fibroblast growth factor 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P09038] | Homo sapiens (human) |
Compound | Definition | Classes | Roles |
---|---|---|---|
tivozanib | N-(2-chloro-4-((6,7-dimethoxy-4-quinolyl)oxy)phenyl)-N'-(5-methyl-3-isoxazolyl)urea: KNR-951 is the HCl, monohydrate salt; an antineoplastic agent; structure in first source | aromatic ether | |
phosphomannopentaose sulfate | phosphomannopentaose sulfate: structure in first source | ||
pg 545 | PG 545: an anti-angiogenesis agent with heparanase inhibitory activity; structure in first source |