Atopic Dermatitis: a Short Summary
Role Of The Microfibrills of Fibrillin In Aging (Ageing) And Photoaging (Photoageing) (Sun-induced Ageing) (For Professionals)
Presentation of fibrillin
- is an extracellular protein
- is responsible as scafolding for deposition elastic fibres
- exists as fibrillin f1 and 2
- encoded by FBN1 and 2
- encoding Marfan syndrome
Functions of fibrillin:
- strengthens elastic fibres and enables transmission of forces between the epidermis and dermis
- What is elastic tissue = elastin + microfibrills fibers
Elastic tissue differences between age groups 18-30 and over 70
- Methodology:
- with atomic force microscopy to determine distance between microfibrills (of fibrillin) (periodicty 56nm=no strain, more than 100=strained and unable to strap back= loss of elasticity)
- With molecular combing, tensile strength to determine distance and elastic potential
- Results:
- Up to 30 years old 0.9% of fibrillin microfibrills are separated by more than 100nm
- Over 70 years old this goes up to 18.2 %
- on immunohistochemistry buttocks vs photoexposed skin in 7o year old individuals show loss of candelabra structure of fibrillinand also a reduction of fibrillin staining in the papillary dermis
Mechanisms of age-related damage:
- upgrading MMPs (matrix metalloproteinase)
- cleavage of proMMP
- upregulation MMP 2 and 9
- degradation of microfibrills by UV
By using atomic force and electron microscopy microfibrills of fibrillin respond to UVB by:
- increasing diameter
- becoming more tangled (increased flexion angle)
- reducing their mass with increasing UV dosage (mass mapping)
UVR exposed fibrillin fibres are therefore:
- shorter
- weaker
- have a reduced mass
Treatment
- Over 4 years of nightly application, retinoic acid 0,1% reduces photoaging by reconstituting the fibrillin quantity and candelabra disposition.
Contributors:
Dr Christophe HSU – dermatologist. Geneva, Switzerland
Griffiths C, Aging and Photoaging – 22nd World Congress of Dermatology (WCD) – Seoul, South Korea
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