Transcript Enzymes - Realmedia

Overview of Ultraviolet Effects:
Acute Damage
Chronic Damage
How is Asian/Chinese Skin
different for photodamage?
UV Pathways to Skin Damage
Damaging effects are 80% UVB/20% UVA
UVB
Direct DNA
damage
UVA
Inflammatory
Mediators
ROS
generation
Inflammatory Mediators
UV Pathways to Skin Damage
Damaging effects are 80% UVB/20% UVA
Inflammatory Mediators
Inflammatory Mediators
UV Pathways to Skin Damage
Damaging effects are 80% UVB/20% UVA
Matrix-degrading
enzymes (MMP, etc)
Enzymes
Matrix-degrading
enzymes (MMP, etc)
Enzymes
UV Pathways to Skin Damage
Damaging effects are 80% UVB/20% UVA
Matrix-degrading
enzymes (MMP, etc)
Enzymes
Matrix-degrading
enzymes (MMP, etc)
Enzymes
UV Pathways to Skin Damage
Damaging effects are 80% UVB/20% UVA
Matrix-degrading
enzymes (MMP, etc)
Enzymes
Both UVA and UVB both
lead to chronic photodamage
UVB
UVA
• Direct DNA damage
– Immune suppression
– Mutations and skin
cancer
• Reactive Oxygen
Species
Inflammation
Pigmentation
Metalloproteineases
Collagen and elastin
degradation
Sagging, wrinkles
Chinese
women 14 –
20 years old
Indian
Chinese
women14
14––
women
20years
yearsold
old
20
Chinese
women 65 75 years old
Indian
women 65 75 years old
How is Asian/Chinese Skin
different for photodamage?
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•
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1.
2.
3.
Skin aging parameters start later than Caucasian1,2 with
different patterns
Within Chinese population, skin aging parameters start
earlier for higher UV exposure by approximately 10
years1
Korean wrinkle formation is highly correlated with sun
exposure3
Pigment changes are different in Asian skin versus
Caucasian with aging and photoaging1
Photoaging differences are not all explained by
differences in pigmentation
Zhao, P. Wang C. Solar ultraviolet Radiation and Skin Damage: An epidemiological study among a Chinese
popoulation. Archives of Environmental Health, 53:6, 1998.
Chung, J.H. Photoaging in Asians. Photodermatology, Photoimmunology & Photomedicine. 19:109-121. 2003
Chung, J.H. Et al. Cutaneous Photodamage in Koreans. Archives of Dermatology 137:1043-1051.
Photodamage is not just about
pigmentation and wrinkles
Photograph courtesy of Robert & Margaret Weiss, MD
Effects of UV on Photoaging:
Conclusions
• UV exposure induces photodamage and
photoaging through several mechanisms
• UVA can produce photoaging in the absence
of UVB
• In order to reduce photodamage, sunscreens
must protect against both UVB and UVA
Photograph courtesy of Robert & Margaret Weiss, MD