Growth factors are special proteins that help skin cells grow, move, and repair damage. They work by attaching to receptors on the surface of skin cells like fibroblasts and keratinocytes, starting signals inside the cells that lead to important changes.
Skin has different types of cells that keep it healthy and strong. Fibroblasts make the supportive material called extracellular matrix, which includes collagen and elastin. These give skin its firmness and stretch. Keratinocytes form the outer layer that protects against germs and injury.[1][2][3]
When skin gets hurt, growth factors kick into action. Platelet-derived growth factor, or PDGF, tells fibroblasts to move to the wound and multiply. Fibroblast growth factor, known as FGF, does the same and also helps blood vessels form. Transforming growth factor beta, or TGF-beta, pushes fibroblasts to produce more matrix materials for healing.[1][2]
Epidermal growth factor, or EGF, mainly targets keratinocytes and fibroblasts. It binds to its receptor and turns on pathways like RAS and PI3K. These paths boost cell growth, slow down cell death, and change how genes work inside the nucleus.[2][5]
TGF-beta has a big role too. It grabs onto receptors on fibroblasts, activating SMAD proteins that go to the nucleus and turn on genes for matrix production. It also uses other paths like PI3K/AKT to help cells survive and fight aging by controlling proteins like p53.[3][4]
These growth factors often team up. For example, immune cells like macrophages release TGF-beta, which then signals fibroblasts to proliferate through paths like AKT and ERK. Fibroblasts send back chemokines and growth factors to guide immune cells.[1][4]
In everyday skin care, growth factors from sources like stem cells bind to receptors on fibroblasts and keratinocytes. This starts signals that firm up skin and reduce fine lines by boosting collagen.[6]
The process starts outside the cell. A growth factor floats in the space around cells and locks onto its matching receptor, like a key in a lock. This causes the receptor to change shape and send messages inside via proteins like RAS, MAPK, or STAT. These messages reach the nucleus, where they switch genes on or off for growth or repair.[2][5]
Fibroblasts sense their surroundings through these signals. At low cell numbers, paths like YAP and Hippo get active to make more growth factors. TGF-beta adds to this by working with space-sensing mechanisms in the matrix.[4]
Growth factors keep skin balanced. They help heal cuts, maintain youthfulness, and respond to stress like sun damage. Their precise interactions ensure skin cells do the right job at the right time.[3]
Sources:
https://pmc.ncbi.nlm.nih.gov/articles/PMC12732683/
https://themedicalbiochemistrypage.org/growth-factors-and-other-cellular-regulators/
https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2025.1681875/full
https://www.pnas.org/doi/10.1073/pnas.2205360119
https://pmc.ncbi.nlm.nih.gov/articles/PMC11631651/
https://majesticcosme.com/blogs/human-stem-cell-serum/fine-lines-to-firm-skin-transformation
