TY - JOUR
T1 - Inhibition of the estrogen receptor alpha signaling delays bone regeneration and alters osteoblast maturation, energy metabolism, and angiogenesis
AU - Wu, Gong Jhe
AU - Chen, Jui Tai
AU - Lin, Pei I.
AU - Cherng, Yih Giun
AU - Yang, Shun Tai
AU - Chen, Ruei Ming
N1 - Publisher Copyright:
© 2020
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Aims: The estrogen-ERα axis participates in osteoblast maturation. This study was designed to further evaluated the roles of the estrogen-ERα axis in bone healing and the possible mechanisms. Main methods: Female ICR mice were created a metaphyseal bone defect in the left femurs and administered with methylpiperidinopyrazole (MPP), an inhibitor of ERα. Bone healing was evaluated using micro-computed tomography. Colocalization of ERα with alkaline phosphatase (ALP) and ERα translocation to mitochondria were determined. Levels of ERα, ERβ, PECAM-1, VEGF, and β-actin were immunodetected. Expression of chromosomal Runx2, ALP, and osteocalcin mRNAs and mitochondrial cytochrome c oxidase (COX) I and COXII mRNAs were quantified. Angiogenesis was measured with immunohistochemistry. Key findings: Following surgery, the bone mass was time-dependently augmented in the bone-defect area. Simultaneously, levels of ERα were specifically upregulated and positively correlated with bone healing. Administration of MPP to mice consistently decreased levels of ERα and bone healing. As to the mechanisms, osteogenesis was enhanced in bone healing, but MPP attenuated osteoblast maturation. In parallel, expressions of osteogenesis-related ALP, Runx2, and osteocalcin mRNAs were induced in the injured zone. Treatment with MPP led to significant inhibition of the alp, runx2, and osteocalcin gene expressions. Remarkably, administration of MPP lessened translocation of ERα to mitochondria and expressions of mitochondrial energy production-related coxI and coxII genes. Furthermore, exposure to MPP decreased levels of PECAM-1 and VEGF in the bone-defect area. Significance: The present study showed the contributions of the estrogen-ERα axis to bone healing through stimulation of energy production, osteoblast maturation, and angiogenesis.
AB - Aims: The estrogen-ERα axis participates in osteoblast maturation. This study was designed to further evaluated the roles of the estrogen-ERα axis in bone healing and the possible mechanisms. Main methods: Female ICR mice were created a metaphyseal bone defect in the left femurs and administered with methylpiperidinopyrazole (MPP), an inhibitor of ERα. Bone healing was evaluated using micro-computed tomography. Colocalization of ERα with alkaline phosphatase (ALP) and ERα translocation to mitochondria were determined. Levels of ERα, ERβ, PECAM-1, VEGF, and β-actin were immunodetected. Expression of chromosomal Runx2, ALP, and osteocalcin mRNAs and mitochondrial cytochrome c oxidase (COX) I and COXII mRNAs were quantified. Angiogenesis was measured with immunohistochemistry. Key findings: Following surgery, the bone mass was time-dependently augmented in the bone-defect area. Simultaneously, levels of ERα were specifically upregulated and positively correlated with bone healing. Administration of MPP to mice consistently decreased levels of ERα and bone healing. As to the mechanisms, osteogenesis was enhanced in bone healing, but MPP attenuated osteoblast maturation. In parallel, expressions of osteogenesis-related ALP, Runx2, and osteocalcin mRNAs were induced in the injured zone. Treatment with MPP led to significant inhibition of the alp, runx2, and osteocalcin gene expressions. Remarkably, administration of MPP lessened translocation of ERα to mitochondria and expressions of mitochondrial energy production-related coxI and coxII genes. Furthermore, exposure to MPP decreased levels of PECAM-1 and VEGF in the bone-defect area. Significance: The present study showed the contributions of the estrogen-ERα axis to bone healing through stimulation of energy production, osteoblast maturation, and angiogenesis.
KW - Angiogenesis
KW - Bone healing
KW - Energy production
KW - Estrogen-ERα axis
KW - Osteoblast maturation
UR - http://www.scopus.com/inward/record.url?scp=85089280882&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85089280882&partnerID=8YFLogxK
U2 - 10.1016/j.lfs.2020.118195
DO - 10.1016/j.lfs.2020.118195
M3 - Article
C2 - 32781073
AN - SCOPUS:85089280882
SN - 0024-3205
VL - 258
JO - Life Sciences
JF - Life Sciences
M1 - 118195
ER -