Core-binding factor beta is required for osteoblast differentiation during fibula fracture healing

Abstract Background Growing evidence has implicated core-binding factor beta (Cbfb) as a contributor to osteoblast differentiation, which plays a key role in fracture healing. Herein, we aimed to assess whether Cbfb affects osteoblast differentiation after fibula fracture. Methods Initially, we established a Cbfb conditional knockout mouse model for subsequent studies. Immunohistochemical staining was conducted to detect the expression of proliferating cell nuclear antigen (PCNA) and collagen II in the fracture end. Next, we isolated and cultured osteoblasts from specific Cbfb conditional knockout mice for BrdU analysis, alkaline phosphatase (ALP) staining, and von Kossa staining to detect osteoblast viability, differentiation, and mineralization, respectively. Western blot analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect the expression of osteoblast differentiation-related genes. Results The Cbfb conditional knockout mice exhibited downregulated expression of PCNA and collagen II, reduced ALP activity, and mineralization, as well as diminished expression of osteoblast differentiation-related genes. Further, Cbfb knockout exerted no obvious effects on osteoblast proliferation. Conclusions Overall, these results substantiated that Cbfb could promote fibula fracture healing and osteoblast differentiation and thus provided a promising therapeutic target for clinical treatment of fibula fracture.

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Core-binding factor beta is required for osteoblast differentiation during fibula fracture healing

10.21203/rs.2.24603/v1 ◽

2020 ◽

Author(s):

Tuanmao Guo ◽

Yan-Li Xing ◽

Zhongning Chen ◽

Xianhong Wang ◽

Hai-Yun Zhu ◽

...

Keyword(s):

Fracture Healing ◽

Knockout Mouse ◽

Osteoblast Differentiation ◽

Conditional Knockout ◽

Core Binding Factor ◽

Knockout Mouse Model ◽

Fibula Fracture ◽

Conditional Knockout Mouse ◽

Binding Factor ◽

Core Binding Factor Beta

Abstract Background: Growing evidence has implicated core-binding factor beta (Cbfb) as a contributor to the osteoblast differentiation, which plays a key role in fracture healing. Here, we conducted the present study with the main objective to assess whether Cbfb affects osteoblast differentiation after fibula fracture. Methods: Initially, Cbfb conditional knockout mouse model was established. Immunohistochemical staining was carried out to detect the expression of proliferating cell nuclear antigen (PCNA) and Collagen II in the fracture end. Then osteoblasts were isolated from specific Cbfb conditional knockout mice and cultured. BrdU method, Alkaline phosphatase (ALP) staining and Von Kossa staining were followed to detect osteoblast proliferation, differentiation and mineralization, respectively. Western blot analysis and RT-qPCR were used to detect the expression of osteoblast differentiation-related genes. Cbfb conditional knockout mouse model was successfully constructed. Results: The mice treated with Cbfb knockout were shown to exhibit significantly decreased expression of PCNA and Collagen II, ALP activity and mineralization, as well as inhibited expression of Runx2, ALP, BglaPl, SPPl, Osteocalcin, Atf4 and Osterix. Further, Cbfb knockout showed no effects on osteoblast differentiation. Conclusion: Overall, these results demonstrated that the Cbfb could potentially promote fibula fracture healing and osteoblast differentiation and thus could comprise a potential means of impeding the progression of fibula fracture.

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An antibody against Siglec-15 promotes bone formation and fracture healing by increasing TRAP+ mononuclear cells and PDGF-BB secretion

Bone Research ◽

10.1038/s41413-021-00161-1 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Gehua Zhen ◽

Yang Dan ◽

Ruomei Wang ◽

Ce Dou ◽

Qiaoyue Guo ◽

...

Keyword(s):

Bone Resorption ◽

Bone Formation ◽

Fracture Healing ◽

Knockout Mice ◽

Mononuclear Cells ◽

Neutralizing Antibody ◽

Conditional Knockout ◽

Anabolic Effect ◽

Antibody Treatment ◽

Conditional Knockout Mice

AbstractOsteoporosis (OP) is a common age-related disease characterized by a deterioration of bone mass and structure that predisposes patients to fragility fractures. Pharmaceutical therapies that promote anabolic bone formation in OP patients and OP-induced fracture are needed. We investigated whether a neutralizing antibody against Siglec-15 can simultaneously inhibit bone resorption and stimulate bone formation. We found that the multinucleation of osteoclasts was inhibited in SIGLEC-15 conditional knockout mice and mice undergoing Siglec-15 neutralizing antibody treatment. The secretion of platelet-derived growth factor-BB (PDGF-BB), the number of tartrate-resistant acid phosphatase-positive (TRAP+) mononuclear cells, and bone formation were significantly increased in the SIGLEC-15 conditional knockout mice and antibody-treated mice. The anabolic effect of the Siglec-15 neutralizing antibody on bone formation was blunted in mice with Pdgfb deleted in TRAP+ cells. These findings showed that the anabolic effect of the Siglec-15 neutralizing antibody was mediated by elevating PDGF-BB production of TRAP+ mononuclear cells. To test the therapeutic potential of the Siglec-15 neutralizing antibody, we injected the antibody in an ovariectomy-induced osteoporotic mouse model, which mimics postmenopausal osteoporosis in women, and in two fracture healing models because fracture is the most serious health consequence of osteoporosis. The Siglec-15 neutralizing antibody effectively reduced bone resorption and stimulated bone formation in estrogen deficiency-induced osteoporosis. Of note, the Siglec-15 neutralizing antibody promoted intramembranous and endochondral ossification at the damaged area of cortical bone in fracture healing mouse models. Thus, the Siglec-15 neutralizing antibody shows significant translational potential as a novel therapy for OP and bone fracture.

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