01 Overview
Basic Fibroblast Growth Factor (bFGF), also known as Fibroblast Growth Factor-2 (FGF-2), is a member of the FGF family, which includes at least 22 structurally related proteins. FGF family members exhibit broad mitogenic and cell survival activities, playing critical roles in embryonic development, cell proliferation, morphogenesis, tissue repair, tumor growth, and invasion.
FGF-2 is a non-glycosylated, heparin-binding growth factor that binds to heparan sulfate proteoglycans (HSPGs) on the cell surface. It is expressed in a wide range of tissues, including the brain, pituitary, kidney, retina, bone, testes, adrenal glands, liver, monocytes, epithelial, and endothelial cells.
02 bFGF Structure
Basic Characteristics
- Protein type: Single-chain polypeptide; FGF family (FGF-2)
- Amino acid sequence: 155 residues (human origin), ~17–18 kDa
- Disulfide bonds: Contains three conserved disulfide bridges (Cys78–Cys96, Cys33–Cys101, Cys68–Cys129) critical for structural stability
3D Structure
- Core architecture: Predominantly β-sheet structure
- Heparin-binding domain: Rich in positively charged residues (e.g., Arg, Lys); enhances binding to heparin/HSPG, stabilizing the protein and facilitating receptor activation. Key Heparin-Binding Sites: Lys128, Arg129, Lys135, etc.
- FGFR-binding sites: Located in the N-terminal (β1–β2 loop) and C-terminal (β10–β12 loop) regions; heparin acts as a co-receptor to form the functional bFGF–FGFR–HSPG ternary complex
Figure 1. Structure of bFGF protein (Source: Wikipedia)
03 Biological Functions of bFGF
1. Promotes Cell Proliferation (e.g., stem cells, fibroblasts)
- Activates MAPK/ERK → Upregulates Cyclin D1/CDK4/6 → Promotes G1/S transition
- Activates PI3K/AKT → Inhibits apoptosis (e.g., decreases BAX, increases BCL-2)
2. Maintains Pluripotency in Stem Cells (e.g., ESCs/iPSCs)
Synergizes with Nanog/OCT4/SOX2 via ERK pathway → Inhibits differentiation, maintains undifferentiated state
3. Induces Differentiation (e.g., neural, osteogenic, vascular)
Cooperates with BMP, WNT, and VEGF to regulate lineage-specific gene expression (e.g., RUNX2 for osteogenesis, PAX6 for neurogenesis)
4. Stimulates Angiogenesis
- Promotes endothelial cell migration and proliferation (in synergy with VEGF)
- Upregulates MMPs for extracellular matrix remodeling
04 Mechanism of Action
bFGF regulates cell proliferation, differentiation, migration, and survival by binding to its receptor (FGFR) and activating downstream signaling pathways.
1. Binding to FGFRs
bFGF binds to fibroblast growth factor receptors (FGFR1–4), which are receptor tyrosine kinases (RTKs). FGFR subtype expression varies by cell type.
2. Role of HSPG
Heparan sulfate proteoglycans stabilize bFGF and enhance FGFR dimerization. HSPGs prevent degradation and increase bFGF–FGFR affinity.
3. Receptor Dimerization and Activation
Ligand binding induces FGFR dimerization and autophosphorylation of tyrosine residues, recruiting adaptor proteins (e.g., FRS2, PLCγ), and activating downstream pathways.
4. Downstream Signaling Pathways
Key signaling pathways include:
Figure 2. bFGF signaling pathway
05 Applications in Stem Cell Research
1. Maintenance of ESC/iPSC Pluripotency
In stem cell therapy, bFGF is a key factor for maintaining the undifferentiated state of ESCs/iPSCs and is often used in combination with TGF-β/Nodal signaling. bFGF promotes stem cell proliferation and inhibits spontaneous differentiation by activating the MAPK/ERK and PI3K/AKT pathways.
- Commonly used at 4–20 ng/mL in culture media
- Requires daily supplementation due to instability at 37°C
2. Promotes MSC Proliferation
- Enhances proliferation and delays senescence
- Maintains multipotency of MSCs from bone marrow, adipose tissue, and umbilical cord
3. Induces Directed Differentiation
- Neural lineage: Stimulates neural stem cell proliferation; works with IGF and PDGF; may support neuroregeneration
- Osteogenic/chondrogenic: Early-stage bFGF enhances osteogenesis (with BMP-2); promotes chondrocyte proliferation in cartilage engineering
- Vascular/endothelial: With VEGF, induces endothelial differentiation for regenerative vascular therapy
4. 3D Culture & Organoid Models
Serves as a core growth factor in organoid systems (e.g., brain, intestine, liver), promoting proliferation and structural formation
5. Medium Optimization
- Serum-free media: Key additive for serum-free/low-serum systems
- Clonal efficiency: Enhances single-cell clone formation by reducing apoptosis
Notes
- Stability: Degrades quickly at 37°C; replenish every 1–2 days
- Concentration: Varies by cell type; typically 4–100 ng/mL
06 Yeasen’s GMP-Grade Recombinant Human FGF2/bFGF
Yeasen offers GMP-grade recombinant human bFGF protein, a critical raw material for stem cell therapy. Our bFGF is produced in E. coli with high activity and purity, free of animal-derived components and compliant with GMP principles.
Product QC Specifications
GMP-Grade Cytokine Quality System
Product Advantages
- Animal-free origin: Free from animal-derived components, animal viruses, pathogenic substances, and exogenous contaminants, ensuring high biosafety.
- Stable quality: Capable of consistent and large-scale production with minimal batch-to-batch variation, ensuring reproducible results.
- Regulatory compliance: Manufacturing equipment and facilities comply with relevant regulatory requirements and follow GMP guidelines, supporting clinical and industrial applications.
- Pharmacopoeia-based release standards: Product is released based on pharmacopoeia standards, guaranteeing reliable quality.
Product Data
High purity
Figure 3. SDS-PAGE and HPLC analysis confirming the purity of human bFGF protein: Purity >95%, no detectable contaminant proteins.
High Bioactivity
Figure 4. Cell proliferation assay using Balb/c 3T3 cells: Biological activity ≥ 5.0 × 10⁶ IU/mg
07 Product Information
|
Product Name |
Cat. No. |
Specification |
|
91341ES |
10 μg / 50 μg / 1 mg |
|
|
91330ES |
10 μg / 50 μg / 100 μg / 1 mg |
|
|
Thermal Stable Recombinant Human bFGF/FGF-2 Protein |
91334ES |
10 μg / 50 μg / 100 μg / 1 mg |
|
Recombinant Human bFGF/FGF-2 Protein (HEK293) |
91344ES |
2 μg / 50 μg / 100 μg / 1 mg |
08 References
[1] Yuanyang T, Yongkang Q, Zhuanggui C, et al. FGF2, an Immunomodulatory Factor in Asthma and Chronic Obstructive Pulmonary Disease (COPD). Front. Cell Dev. Biol., April 2, 2020, Volume 8.