Open AccessTotal flavonoids of Rhizoma Drynariae enhances CD31hiEmcnhi vessel formation and subsequent bone regeneration in rat models of distraction osteogenesis by activating PDGF‑BB/VEGF/RUNX2/OSX signaling axis
Author(s) -
Zhen Shen,
Wei Dong,
Zehua Chen,
Guoqian Chen,
Yan Zhang,
Zige Li,
Haibiao Lin,
Huamei Chen,
Minling Huang,
Ying Guo,
Ziwei Jiang
Publication year - 2022
Publication title -
international journal of molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.048
H-Index - 90
eISSN - 1791-244X
pISSN - 1107-3756
DOI - 10.3892/ijmm.2022.5167
Subject(s) - regeneration (biology) , cd31 , cell cycle , runx2 , chemistry , apoptosis , microbiology and biotechnology , angiogenesis , biology , biochemistry , cancer research , osteoblast , in vitro
Total flavonoids of Rhizoma Drynariae (TFRD), extracted from the kidney‑tonifying Traditional Chinese medicine Rhizoma Drynariae , can be effective in treating osteoporosis, bone fractures and defects. However, the pharmacological effects of TFRD on the specific vessel subtype CD31 hi Emcn hi during distraction osteogenesis (DO) remains unclear. The present study aimed to investigate the effects of TFRD on CD31 hi Emcn hi vessels in a rat model of DO. In the present study, tibial DO models were established using 60 rats with a distraction rate of 0.2 mm per day for 20 days. Co‑immunofluorescence staining of CD31 and endomucin (Emcn) was conducted to determine CD31 hi Emcn hi vessels. Radiographic, angiographic and histological analyses were performed to assess bone and vessel formation. Tube formation, alkaline phosphatase (ALP) and Von Kossa staining assays were performed to test angiogenesis of endothelial precursor cells (EPCs) and osteogenesis of bone marrow‑derived mesenchymal stem cells (BMSCs). Additionally, expression levels of platelet‑derived growth factor (PDGF)‑BB, VEGF, runt‑related transcription factor 2 (RUNX2) and Osterix (OSX) were determined by western blotting and reverse transcription‑quantitative PCR. The in vivo assays demonstrated that TFRD markedly promoted CD31 hi Emcn hi vessel formation during DO, whereas PDGF‑BB neutralizing antibody suppressed vessel formation. Furthermore, the ALP, Von Kossa staining and tube formation assays indicated that TFRD notably elevated the angiogenic capacity of EPCs and osteogenic capacity of BMSCs under stress conditions, which was significantly suppressed by blocking PDGF‑BB. The protein and mRNA levels of PDGF‑BB, VEGF, RUNX2 and OSX were upregulated by TFRD, but downregulated by blocking PDGF‑BB. Thus, TFRD could facilitate CD31 hi Emcn hi vessel formation and subsequently enhance angiogenic‑osteogenic coupling to regenerate bone defects during DO via the PDGF‑BB/VEGF/RUNX2/OSX signaling axis, which indicated that CD31 hi Emcn hi vessels could be a potential novel therapeutic target for DO, and TFRD may represent a promising drug for promoting bone regeneration in DO by increasing CD31 hi Emcn hi vessels.