About Growth Factors and Aging

Aging of your skin may be regarded as a cellular process that is partially genetically determined, and partially influenced by environmental factors (i.e. sun damage, air pollutants, etc.). The most obvious changes in your skin due to aging include wrinkling, laxity, dryness, and general thinning of the skin. Prominent wrinkling is caused by the loss of dermal collagen content, and a decreased rate of collagen production.¹ Collagen is a protein fiber that is the basic building block of the skin, and provides skin’s structure (thickness) and resilience. As you age, your skin loses around 1% of the number of fibroblast cells and 1% of its thickness per year.¹ Dermal fibroblast cells are the "construction workers" of skin, that function to produce new collagen and maintain your skin’s structure. Decline in the number of fibroblast cells results in less collagen production, decreased concentration levels of growth factors, and thinner, wrinkled skin. The rate of decline in fibroblast cell number and function is increased by sun exposure, and recent studies have also shown that sun damaged skin has 35% fewer blood capillaries than normal skin³ thus is receiving less nutrients and oxygen than normal skin.

Growth factors, or high-molecular-weight peptides, are the regulatory biological (chemical) signals involved in the regulation of cell growth and function.^1,3 Their function is to trigger cells to divide and grow, and to produce matrix proteins like collagen.¹ In the skin, local skin cells produce and maintain most of its growth factor concentration levels. The TGF-b family (transforming growth factor-beta) is considered to be the most important growth factor group in skin because the majority of skin cells recognize their signals.² TGF-b is a potent stimulator of collagen production, promotes the synthesis of extracellular matrix proteins, and inhibits matrix degradation (thinning of your skin).^1,2,3 Other essential skin growth factors include PDGF (Platelet-derived growth factor) and GM-CSF (Granulocyte-macrophage colony-stimulating factor), which can also stimulate extracellular matrix production, reduce inflammation, and promote the formation of new blood vessels.^1,3

Although each growth factor has different effects on skin cells’ functions, the combined action of multiple growth factors and proteins is required for optimal growth, stimulation, and synergy of skin cell behavior. For example, in order for TGF-b to stimulate fibroblast cell growth, the presence of PDGF is required.³ Thus the application of ReLuma, which contains 9 different growth factors and proteins, versus other skin care products containing only a single growth factor, results in a more effective system for stimulating skin rejuvenation and regeneration. ReLuma’s combined delivery of multiple, natural human growth factors has the ability to stimulate fibroblast production of collagen, stimulate keratinocyte and fibroblast proliferation, enhance blood vessel formation, and work as a potent anti-inflammatory agent in skin. These processes may then function to increase skin firmness and elasticity, reduce the appearance of fine lines and wrinkles, increase skin moisturization and vibrancy, develop a smoother, silkier texture, even out skin colors and tones, and may result in thicker, younger looking skin.

1. Molecular Aspects of Dermatology. GC Priestley, ed. John Wiley & Sons, NY 1993.
2. Arch Dermatology 138(11): 1462-70. 2002
3. Growth Factors and Wound Healing. Ziegler, Pierce, Herndon, ed. Springer-Verlag, NY 1997.