Increased deposition of fibulin-2 in solar elastosis and its colocalization with elastic fibres.
BACKGROUND
Fibulin-2 is a 195-kDa protein belonging to a novel family of extracellular matrix proteins that might be involved in microfibril and elastic fibre organization.


OBJECTIVE
To determine the localization of fibulin-2 in relation to elastic fibres in normal skin and in solar elastosis characterized by increased elastotic material in the papillary dermis.


METHODS
The expression and synthesis of fibulin-2 was investigated by means of in situ hybridization, immunohistochemistry and Western blot analysis in normal and photoaged skin.


RESULTS
Immunohistochemistry and elastic tissue staining revealed that fibulin-2 deposition mainly colocalized with microfibrils and elastin fibres, with a marked staining of elastotic material in solar elastosis. Western blot analysis demonstrated that in photoaged skin fibulin-2 showed the same electrophoretic mobility as in sun-protected skin. However, in actinic elastosis the amount of fibulin-2 was significantly higher. In addition, smaller degradation products were detectable, presumably reflecting increased proteinase activity in photodamaged skin.


CONCLUSIONS
This study shows that deposition of fibulin-2 and elastin is highly co-ordinated, indicating that this protein plays an important role in elastic fibre and microfibril formation in normal and actinically damaged skin.
Hunzelmann
N
N
Department of Dermatology, University of Cologne, Joseph Stelzmann Str. 9, 50924 Cologne, Germany. nico.hunzelmann@uni-koeln.de
Nischt
R
R
Brenneisen
P
P
Eickert
A
A
Krieg
T
T
D000368:Aged; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D004547:Elastic Tissue / Q000378:metabolism*; D004549:Elastin / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D008875:Middle Aged; D015595:Skin Aging / Q000502:physiology*
D002135:Calcium-Binding Proteins; D016326:Extracellular Matrix Proteins; C084612:fibulin 2; D004549:Elastin