Conditional expression of constitutively active estrogen receptor α in chondrocytes impairs longitudinal bone growth in mice.
Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caERα(ColII), expressing constitutively active mutant estrogen receptor (ER) α in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caERα(ColII) mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caERα(ColII) mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caERα(ColII) mice. These results suggest that ERα is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.
Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan.
Kazuhiro
K
Ikeda
Tohru
T
Tsukui
Yukiko
Y
Imazawa
Kuniko
K
Horie-Inoue
Satoshi
S
Inoue
D000818:Animals; D001846:Bone Development / Q000235:genetics / Q000502:physiology*; D001842:Bone and Bones / Q000002:abnormalities*; D049109:Cell Proliferation; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D020219:Chondrogenesis / Q000235:genetics / Q000502:physiology*; D047628:Estrogen Receptor alpha / Q000096:biosynthesis* / Q000235:genetics; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic
D047628:Estrogen Receptor alpha