Kruppel-like factor 5 causes cartilage degradation through transactivation of matrix metalloproteinase 9.
Although degradation of cartilage matrix has been suggested to be a rate-limiting step for endochondral ossification during skeletal development, little is known about the transcriptional regulation. This study investigated the involvement of KLF5 (Krüppel-like factor 5), an Sp/KLF family member, in the skeletal development. KLF5 was expressed in chondrocytes and osteoblasts but not in osteoclasts. The heterozygous deficient (KLF5+/-) mice exhibited skeletal growth retardation in the perinatal period. Although chondrocyte proliferation and differentiation were normal, cartilage matrix degradation was impaired in KLF5+/- mice, causing delay in replacement of cartilage with bone at the primary ossification center in the embryonic limbs and elongation of hypertrophic chondrocyte layer in the neonatal growth plates. Microarray analyses identified MMP9 (matrix metalloproteinase 9) as a transcriptional target, since it was strongly up-regulated by adenoviral transfection of KLF5 in chondrogenic cell line OUMS27. The KLF5 overexpression caused gelatin degradation by stimulating promoter activity of MMP9 without affecting chondrocyte differentiation or vascular endothelial growth factor expression in the culture of chondrogenic cells; however, in osteoclast precursors, it affected neither MMP9 expression nor osteoclastic differentiation. KLF5 dysfunction by genetic heterodeficiency or RNA interference was confirmed to cause reduction of MMP9 expression in cultured chondrogenic cells. MMP9 expression was decreased in the limbs of KLF5+/- embryos, which was correlated with suppression of matrix degradation, calcification, and vascularization. We conclude that KLF5 causes cartilage matrix degradation through transcriptional induction of MMP9, providing the first evidence that transcriptional regulation of a proteinase contributes to endochondral ossification and skeletal development.
Shinoda
Yusuke
Y
Sensory and Motor System Medicine, University of Tokyo, Tokyo 113-8655, Japan.
Ogata
Naoshi
N
Higashikawa
Akiro
A
Manabe
Ichiro
I
Shindo
Takayuki
T
Yamada
Takashi
T
Kugimiya
Fumitaka
F
Ikeda
Toshiyuki
T
Kawamura
Naohiro
N
Kawasaki
Yosuke
Y
Tsushima
Kensuke
K
Takeda
Norifumi
N
Nagai
Ryozo
R
Hoshi
Kazuto
K
Nakamura
Kozo
K
Chung
Ung-il
UI
Kawaguchi
Hiroshi
H
D000818:Animals; D002356:Cartilage / Q000166:cytology / Q000196:embryology*; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D005121:Extremities / Q000196:embryology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D011401:Promoter Regions, Genetic / Q000502:physiology; D034622:RNA Interference; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000502:physiology*
C492214:KLF5 protein, human; C118391:Klf5 protein, mouse; D051741:Kruppel-Like Transcription Factors; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse