Fibulin-5 deposition in human skin: decrease with ageing and ultraviolet B exposure and increase in solar elastosis.
BACKGROUND
Fibulin-5 was recently found as a secreted extracellular matrix protein that functions as a scaffold for elastic fibres. However, the distribution of fibulin-5 in human skin and its changes during the ageing process are not known.


OBJECTIVE
To explore the involvement of fibulin-5 in skin ageing, the age-dependent changes in fibulin-5 localization in human skin were examined compared with those of other elastic fibre components including elastin, fibrillin-1 and fibulin-2. Methods The distribution of elastin, fibrillin-1, fibrillin-2, fibulin-2 and fibulin-5 was investigated by means of immunohistochemistry using their specific antibodies. Skin samples were recovered from 12 healthy subjects undergoing plastic surgery. Ultraviolet (UV) B-irradiated or control nonirradiated buttock skin samples were obtained from two healthy volunteers at 2 days after the irradiation at 2 minimal erythemal doses.


RESULTS
In the reticular dermis of young sun-protected skin from the upper arm, fibulin-5 colocalized with the other elastic fibre components, while in the papillary dermis fibulin-5 showed candelabra-like structures perpendicular to the epidermis with an unstained area just beneath the epidermis, which was similar to that of elastin but not fibrillin-1. Fibulin-5 in the reticular dermis decreased and disappeared with age even in sun-protected skin from the thigh, abdomen and upper arm. In sun-exposed skin, fibulin-5 was extremely reduced in the dermis of cheek skin even from a 20-year-old man. UVB irradiation reduced fibulin-5, fibulin-2 and elastin markedly, moderately and weakly, respectively, compared with levels in control nontreated skin. Interestingly, the deposition of fibulin-5 was increased in solar elastosis, like that of other elastic fibre components.


CONCLUSIONS
These results suggest that fibulin-5 is a good marker of skin ageing and that the earlier loss of fibulin-5 may involve age-dependent changes in other elastic fibre components.
Kadoya
K
K
Skin Biology Research Laboratories, Shiseido Life Science Research Centre, 2-12-1 Fukuura, Kanazawa-ku, Yokohama-shi 236-8643, Japan.
Sasaki
T
T
Kostka
G
G
Timpl
R
R
Matsuzaki
K
K
Kumagai
N
N
Sakai
L Y
LY
Nishiyama
T
T
Amano
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002135:Calcium-Binding Proteins / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D003240:Connective Tissue Diseases / Q000378:metabolism*; D020405:Dermis / Q000737:chemistry* / Q000528:radiation effects; D004549:Elastin / Q000032:analysis; D016326:Extracellular Matrix Proteins / Q000032:analysis*; D005260:Female; D000071838:Fibrillin-1; D000071840:Fibrillin-2; D000071837:Fibrillins; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008840:Microfilament Proteins / Q000032:analysis; D008875:Middle Aged; D011994:Recombinant Proteins / Q000032:analysis*; D015595:Skin Aging / Q000502:physiology*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D054392:Adipokines
D015415:Biomarkers; D002135:Calcium-Binding Proteins; D004549:Elastin; D016326:Extracellular Matrix Proteins; D000071838:Fibrillin-1; D000071840:Fibrillin-2; D000071837:Fibrillins; D008840:Microfilament Proteins; D011994:Recombinant Proteins; C492373:FBLN5 protein, human; C000605722:FBN1 protein, human; D054392:Adipokines; C000605723:FBN2 protein, human; C084612:fibulin 2