YKL-40 secreted from adipose tissue inhibits degradation of type I collagen.
Obesity is considered a chronic low-grade inflammatory status and the stromal vascular fraction (SVF) cells of adipose tissue (AT) are considered a source of inflammation-related molecules. We identified YKL-40 as a major protein secreted from SVF cells in human visceral AT. YKL-40 expression levels in SVF cells from visceral AT were higher than in those from subcutaneous AT. Immunofluorescence staining revealed that YKL-40 was exclusively expressed in macrophages among SVF cells. YKL-40 purified from SVF cells inhibited the degradation of type I collagen, a major extracellular matrix of AT, by matrix metalloproteinase (MMP)-1 and increased rate of fibril formation of type I collagen. The expression of MMP-1 in preadipocytes and macrophages was enhanced by interaction between these cells. These results suggest that macrophage/preadipocyte interaction enhances degradation of type I collagen in AT, meanwhile, YKL-40 secreted from macrophages infiltrating into AT inhibits the type I collagen degradation.
Iwata
Takeo
T
Department of Medical Pharmacology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8504, Japan.
Kuwajima
Masamichi
M
Sukeno
Akiko
A
Ishimaru
Naozumi
N
Hayashi
Yoshio
Y
Wabitsch
Martin
M
Mizusawa
Noriko
N
Itakura
Mitsuo
M
Yoshimoto
Katsuhiko
K
D017667:Adipocytes / Q000378:metabolism* / Q000473:pathology; D054392:Adipokines; D000273:Adipose Tissue / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D000071451:Chitinase-3-Like Protein 1; D018920:Coculture Techniques; D024042:Collagen Type I / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D037102:Lectins; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology
D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D024042:Collagen Type I; D006023:Glycoproteins; D037102:Lectins; D020781:Matrix Metalloproteinase 1