Rui Xu1, Cheng Luo2, Qinwen Ge1, Jun Ying1, Peng Zhang1, Chenjie Xia1, Liang Fang1, Huihui Xu1, Wenhua Yuan3, Taotao Xu4, Shuaijie Lv5, Hongting Jin3, Peijian Tong4, Kun Tian6, Pinger Wang7. 1. The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China; Institute of Orthopadics and Traumatology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. 2. The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China; Hangzhou Fuyang Hospital of TCM Orthopedics and Traumatology, Hangzhou, China. 3. Institute of Orthopadics and Traumatology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. 4. Department of Orthopedic Surgery, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. 5. The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China; Department of Orthopedic Surgery, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. 6. Department of Orthopedic Surgery, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. Electronic address: 502509825@qq.com. 7. Institute of Orthopadics and Traumatology, the First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China. Electronic address: apple63209321@126.com.
Abstract
BACKGROUND: Radix Rehmanniae Praeparata (RR), the steamed roots of Rehmannia glutinosa, is a traditional Chinese medicine with the function of kidney-nourishing, and it has been safety used for centuries to treat bone-related disorders. The aim of this study is to investigate the positive effect and underlying mechanism of RR enhancing bone fracture healing in mouse model. METHODS: Ten-week-old C57BL/6J mice were subjected to a unilateral open transverse tibial fracture and provided a daily treatment of RR. Bone samples were harvested for tissue analyses including x-ray, μCT, histology, histomorphometry, biomechanical testing, immunohistochemical (IHC) and quantitative gene expression analysis. To determine the role of TGF-β in accelerating fracture healing effect of RR, aforementioned experiments were performed on Gli1-CreER; Tgfbr2 flox/flox (Tgfbr2Gli1ER) conditional knockout mice. RESULTS: RR promoted bone fracture healing and strengthened bone intensity in wild-type and Cre- mice with the activation of TGF-β/Smad2 signaling, on the contrary, RR failed to accelerating fracture healing in Tgfbr2Gli1ER mice. CONCLUSION: RR promotes bone fracture healing by intensify the contribution of Gli1+ cells on bone and cartilage formation mainly in TGF-β-dependent manner. RR is an alternative option for clinical treatment of fracture.
BACKGROUND: Radix Rehmanniae Praeparata (RR), the steamed roots of Rehmannia glutinosa, is a traditional Chinese medicine with the function of kidney-nourishing, and it has been safety used for centuries to treat bone-related disorders. The aim of this study is to investigate the positive effect and underlying mechanism of RR enhancing bone fracture healing in mouse model. METHODS: Ten-week-old C57BL/6J mice were subjected to a unilateral open transverse tibial fracture and provided a daily treatment of RR. Bone samples were harvested for tissue analyses including x-ray, μCT, histology, histomorphometry, biomechanical testing, immunohistochemical (IHC) and quantitative gene expression analysis. To determine the role of TGF-β in accelerating fracture healing effect of RR, aforementioned experiments were performed on Gli1-CreER; Tgfbr2 flox/flox (Tgfbr2Gli1ER) conditional knockout mice. RESULTS:RR promoted bone fracture healing and strengthened bone intensity in wild-type and Cre- mice with the activation of TGF-β/Smad2 signaling, on the contrary, RR failed to accelerating fracture healing in Tgfbr2Gli1ER mice. CONCLUSION:RR promotes bone fracture healing by intensify the contribution of Gli1+ cells on bone and cartilage formation mainly in TGF-β-dependent manner. RR is an alternative option for clinical treatment of fracture.