Expression of 36-kDa microfibril-associated glycoprotein (MAGP-36) in human keratinocytes and its localization in skin.
Microfibril-associated glycoprotein-36 (MAGP-36) is a recently isolated elastin-binding protein and considered to be a member of microfibril-associated glycoproteins (MAGPs). We studied the expression of MAGP-36 in cultured normal human keratinocytes and its localization in the skin. MAGP-36 was found to be expressed in cultured human keratinocytes by Western blot and RT-PCR assays. The levels of MAGP-36 (polypeptide and mRNA) and the number of MAGP-36-producing keratinocytes were greatly increased during Ca(2+)-induced differentiation of keratinocytes. Immunohistochemical studies demonstrated that MAGP-36 colocalized with elastic fibers and formed candelabra like-fibers in the superficial dermis of normal skin. In the elderly skin of sun-exposed region, immunoreactivity of MAGP-36 in the superficial dermis disappeared. In the lesional skin of pseudoxanthoma elasticum which is an elastin-related disorder, immunoreactivity of MAGP-36 was found in the accumulation of disintegrated elastic fibers. The results show that MAGP-36 is a component of elastic fibers in the dermis and co-operates with elastin in normal and diseased conditions.
Hirano
Eiichi
E
Department of Biochemical Engineering and Science, Kyusyu Institute of Technology, Iizuka, Fukuoka, Japan.
Fujimoto
Norihiro
N
Tajima
Shingo
S
Akiyama
Minoru
M
Ishibashi
Akira
A
Kobayashi
Ryoji
R
Okamoto
Kouji
K
D000368:Aged; D000375:Aging / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D003285:Contractile Proteins / Q000378:metabolism*; D006023:Glycoproteins; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D011561:Pseudoxanthoma Elasticum / Q000378:metabolism / Q000473:pathology; D012016:Reference Values; D012867:Skin / Q000378:metabolism* / Q000528:radiation effects; D014018:Tissue Distribution
D003285:Contractile Proteins; D006023:Glycoproteins; C120974:MAGP-36 protein, human