Different bone remodeling levels of trabecular and cortical bone in response to changes in Wnt/β-catenin signaling in mice.
Trabecular bone and cortical bone have different bone remodeling levels, and the underlying mechanisms are not fully understood. In the present study, the expression of Wnt/β-catenin signaling and its downstream molecules along with bone mass in trabecular and cortical bone were compared in wild-type mice, constitutive activation of β-catenin (CA-β-catenin) mice and β-catenin deletion mice. It was found that the expression level of most of the examined genes such as Wnt3a, β-catenin, osteocalcin and RANKL/OPG ratio were significantly higher in trabecular bone than in cortical bone in wild-type mice. CA-β-catenin resulted in up-regulated expression of the above-mentioned genes except for RANKL/OPG ratio, which were down-regulated. Also, CA-β-catenin led to increased number of osteoblasts, decreased number of osteoclasts and increased bone mass in both the trabecular bone and cortical bone compared with wild-type mice; however, the extent of changes was much greater in the trabecular bone than in the cortical bone. By contrast, null β-catenin led to down-regulated expression of the above-mentioned genes except for RANKL/OPG ratio. Furthermore, β-catenin deletion led to decreased number of osteoblasts, increased number of osteoclasts and decreased bone mass when compared with wild-type mice. Again, the extent of these changes was more significant in trabecular bone than cortical bone. Taken together, we found that the expression level of Wnt/β-catenin signaling and bone remodeling-related molecules were different in cortical bone and trabecular bone, and the trabecular bone was more readily affected by changes in the Wnt/β-catenin signaling pathway. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:812-819, 2017.
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Junfeng
J
Li
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Quanwei
Q
Bao
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Sixu
S
Chen
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Huayu
H
Liu
Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M Health Science Center, Dallas, Texas 75246.
Jianquan
J
Feng
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Hao
H
Qin
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Ang
A
Li
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Daocheng
D
Liu
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Yue
Y
Shen
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Yufeng
Y
Zhao
Department of Trauma Surgery, State Key Laboratory of Trauma, Burn and Combined Injury, Daping Hospital, Third Military Medical University, ChongQing 400042, China.
Zhaowen
Z
Zong
D000818:Animals; D016723:Bone Remodeling; D001842:Bone and Bones / Q000378:metabolism; D000071556:Cancellous Bone / Q000502:physiology*; D000071538:Cortical Bone / Q000502:physiology*; D005786:Gene Expression Regulation; D051379:Mice; D008822:Mice, Transgenic; D010006:Osteoblasts / Q000378:metabolism; D010010:Osteoclasts / Q000378:metabolism; D053245:RANK Ligand / Q000378:metabolism; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism; D060449:Wnt Signaling Pathway; D055114:X-Ray Microtomography; D051176:beta Catenin / Q000378:metabolism
C495267:CTNNB1 protein, mouse; D053245:RANK Ligand; C505689:Tnfsf11 protein, mouse; D051153:Wnt Proteins; D051176:beta Catenin
Wnt/β-catenin; bone remodeling; cortical bone; difference; trabecular bone