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Collagen: Structure and Function
Course Author—Dr. Zoe Draelos, M.D.
• Nu Skin Professional Advisory Board Member.
• Board certified dermatologist in High Point, North
Carolina, and clinical associate professor of
dermatology at Wake Forest University School of
Medicine, Winston-Salem, North Carolina.
• Board of directors member for and fellow of the
American Academy of Dermatology.
• Author of Cosmetics in Dermatology; has written
240 published papers and serves on five journal
editorial boards.
Did You Know?
Collagen makes up 75 percent of our
skin and more than a third of the
body's protein is collagen?
Find out more about collagen in this
course.
Dermis
Collagen
Fibers
Objectives
After viewing this course, you should have an understanding of the
following:
• Basic structure and function of collagen
• Relationship between collagen and beauty
• The collagen production process
• How collagen is broken down
• How to preserve and promote healthy collagen levels
Previous Curriculum Review—The Skin
The skin is a complex organ
composed of multiple layers. All
layers of the skin can be divided into
two main sections:
• Epidermis
• Dermis
Beneath these sections is a
subcutaneous layer of fat called the
hypodermis. While not an official
section of the skin, the hypodermis
provides essential support.
Epidermis
Dermis
Hypodermis
Muscle
Previous Curriculum Review—Dermis
The dermis is a fibrous, mesh-like
network of tissue that provides
structure and gives skin its
resilience. Major components of the
dermis include the following:
Epidermis
Dermal Epidermal
Junction
Mast
Cell
• Collagen
• Elastin
• Glycosaminoglycans
Dermis
Elastin
Fiber
• Blood and lymph vessels
• Specialized cells: mast cells and
fibroblasts
Collagen
Fiber
Glycosaminoglycans
Blood Vessels
Fibroblast Cell
What Is Collagen?
What Is Collagen?
Collagen is the body’s major structural
protein and is composed of three
protein chains wound together in a
tight triple helix. This unique
structure gives collagen a greater
tensile strength than steel.
Dermis
Collagen
Fibers
What Is Collagen?
Approximately 33 percent of the protein in the
body is collagen, supporting tissues and organs,
and connecting these structures to bones. In
fact bones are also composed of collagen
combined with certain minerals such as calcium
and phosphorus.
What Is Collagen?
Collagen plays a key role in providing the structural scaffolding
surrounding cells that helps to support cell shape and
differentiation, somewhat like steel rods reinforce a concrete
block.
The mesh like collagen network binds cells together and
provides the supportive framework or environment in which cells
develop and function, and tissues and bones heal.
Without collagen the body would literally fall apart.
Collagen and Beauty
Collagen and Beauty
Epidermis
Dermis
Collagen
Fibers
The skin is composed mostly of
collagen proteins—about 75
percent—so the smooth, plump
appearance of young, healthy skin is
due in large part to the presence of
healthy collagen levels.
Found in the dermis layer, the meshlike framework of collagen gives the
skin its strength and durability.
Collagen and Beauty
The breakdown of healthy collagen and
the decline in collagen production leads
to the development of unwanted
wrinkles and the appearance of aged
skin.
Collagen and Beauty
Beauty seekers around the globe
search for new ways to boost
collagen levels and repair past
collagen damage, going so far as to
inject collagen proteins into the skin
to plumb wrinkles and add volume to
the lips.
Collagen Synthesis
Collagen Synthesis
Collagen is synthesized by
fibroblasts—specialized skin cells
located in the dermal layer of the skin.
Fibroblasts also produce other skin
structural components such as elastin
and glucosaminoglycans (GAGs).
Elastin gives the skin its ability to snap
back. GAGs make up the ground
substance that keeps the dermis
hydrated.
Fibroblasts
Collagen Synthesis
In order to signal or turn on the production of skin structural proteins,
fibroblast cells have specially shaped receptors on their outside
membranes that act as binding sites into which signal molecules with a
matching shape, can fit.
When the receptors are bound by the correct combination of signal
molecules, called fibroblast growth factors (FGFs), the fibroblast
begins the production of collagen.
Collagen Synthesis
Fibroblasts first produce short collagen subunits called procollagen,
which are transported out of the fibroblast cells and then later joined
together to form the complete collagen molecule. Vitamin C plays a
key role in many steps of this process.
Without sufficient levels of vitamin C, collagen formation is disrupted.
This leads to a wide variety of disorders such as scurvy, a disease
where the body cannot produce collagen and essentially all support
structures deteriorate and the body falls apart.
Collagen Synthesis
Collagen synthesis occurs
continuously throughout our lives to
repair and replace damaged collagen
tissue or build new cellular structures.
With age collagen levels decline as a
result of decreased production and
increased degradation.
Collagen Degradation
Collagen Degradation
The degradation and recycling of old and
damaged collagen is a healthy natural
process used to create protein fragments
needed to build new cellular structures as in
the healing process.
Although the breakdown of collagen is a
necessary process, UV radiation and
environmental stressors push collagen
degradation into overdrive.
Free radicals induced by UV
radiation attacking a cell
Collagen Degradation
There are two main ways that UV light and other environmental stressors
decrease healthy collagen levels:
• Ultraviolet rays and environmentally induced free radicals directly
damage/mutate fibroblast DNA. When the genetic blueprint is
mutated weakened collagen fibers are produced.
• Free radicals from UV radiation and other environmental
stressors oxidize and damage the collagen fibers.
Collagen Degradation
Environmental stressors such as UV
radiation, ozone, pollution, and cigarette
smoke—and the resulting inflammation—all
produce free radicals that oxidize and
weaken the actual collagen fiber.
Also, in response to this free radical
oxidation, excess amounts of
metalloproteinase (MMP) enzymes are
produced. Collagenase is the main MMP
that degrades collagen.
Collagen Degradation
Remember, the normal function of metalloproteinases (specifically
collagenase) is necessary to heal sun-injured or free radical damaged
tissue as it creates building fragments used in the formation of new
collagen.
As cellular processes and available energy decline, these enzymes
become dysfunctional and overly active, resulting in the formation of
disorganized areas within the collagen matrix, referred to by
dermatologists as solar scars. These weakened areas develop into
wrinkles.
Protecting and Promoting Collagen
Protecting Collagen
The first step in maintaining a healthy,
youthful looking appearance is the
protection of current collagen levels.
There are two main ways to protect
healthy collagen and prevent future
collagen degradation:
• Avoid UVA and UVB radiation.
• Prevent free radical damage with a
complete antioxidant defense
network.
Protecting Collagen
Exposure to ultraviolet (UVA and UVB) radiation emanating from the
sun is the most prolific cause of premature skin aging, accounting for
an estimated 90 percent of the signs associated with aging skin.
UV exposure must be limited and individuals should wear a daily
sunscreen to protect healthy collagen.
Many skin care companies understand this need and incorporate
sunscreens into their daytime moisturizers.
Protecting Collagen
The second preventative step in protecting existing and future
collagen levels is supplementation with both oral and topical
antioxidants.
As antioxidants fight free radicals from UV light, ozone, pollution,
cigarettes, and internal metabolic processes, they prevent the
degradation of existing collagen fibers and protect the healthy function
of fibroblast cells.
Protecting Collagen
Antioxidants work optimally as a
network to protect cellular health
and viability. Some antioxidants in
the network fight free radicals
directly enabling other antioxidants
to perform their critical functions.
Key antioxidants in the defense
network are carotenoids, CoQ10,
and Vitamins C and E.
Vitamin C
CoQ10
CoQ10
(Carotenoids)
Promoting Collagen
There are many ways in which to
promote the synthesis of new, healthy
collagen:
• Provide the skin with a reservoir of
vitamin C.
• Chemical exfoliation with acids.
• Supplement with collagen
stimulating peptides.
Promoting Collagen
As a necessary component in the
synthesis process of collagen, vitamin
C is proven to increase production.
One study showed prolonged exposure
of human connective tissue cells to
vitamin C stimulated an eight-fold
increase in the synthesis of collagen
(Murad et al., 1981).
Promoting Collagen
Chemical exfoliants, such as alpha hydroxy acids and poly
hydroxy acids break the bonds between cells of the stratum
corneum and slough away dead skin. Consistent exfoliation
stimulates cell renewal.
Chemical exfoliation has also shown to increase dermal
thickness. Scientists attribute this thickening to the synthesis of
glycosaminoglycans and collagen within the dermis.
Promoting Collagen
Fibroblasts are naturally stimulated to begin the synthesis of collagen
when specific combinations of peptide signal molecules (fibroblast
growth factors) bind to receptor sites on the fibroblast membrane.
These signal molecules can be supplemented topically and help to
boost collagen production. Some skin care companies are including
these peptide fragments in their treatment products.
Collagen Review
Collagen—Review
• Collagen is a major structural protein that plays a key role in providing the
structural scaffold for cells, tissues, and organs. Without collagen the body
would fall apart.
• Collagen gives the skin its strength and durability and is responsible for the
smooth, plumb appearance of young, healthy skin
• Fibroblast growth factors bind to fibroblast receptors to trigger production of
collagen. Vitamin C is essential for collagen synthesis.
• UV radiation and environmental stressors stimulate collagenase which
increases the degradation of collagen.
• Three ways to protect and promote collagen are consistently wearing
sunscreen, chemically exfoliating and using products that contain Vitamin C.
Test Your Knowledge
Congratulations!
You have completed the
Collagen: Skin Structural Protein course.