title: Study design: in vitro and in vivo assessment of bone morphogenic protein 2 combined with platelet-rich plasma on treatment of disc degeneration.
abstract: Our aim was to investigate the biological effects of bone morphogenic protein 2 (BMP2) on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into chondrocyte-like cells in platelet-rich plasma (PRP) gel in vitro. In addition, the effectiveness of BMP2-transduced BMSCs in combined with PRP gel to repair the degenerated intervertebral disc in a rabbit model was also evaluated. Previous studies have shown that tissue engineering provides many promising advantages to treating disc degeneration and may reverse the pathological process of disc degeneration.
  
  
  
  The expressions of types I, II and X collagen, aggrecan and Sox9 of the BMP2-transduced BMSCs in monolayer or PRP gel were examined by reverse transcriptase polymerase chain reaction (RT-PCR). Sixty New Zealand white rabbits were divided into five groups: 12 normal controls; 12 puncture operated with only disc degeneration being induced; 12 PRP transplantation animals; 12 BMSC and PRP-transplantation animals; 12 BMP2-transduced BMSCs and PRP-transplantation animals. The effect of BMP2-transduced BMSCs on degenerated discs were evaluated by magnetic resonance image (MRI) scan, histology, immunohistochemistry and Western blot analysis.
  
  
  
  BMP2 could facilitate chondrogenic differentiation of BMSCs in monolayer or PRP gel. The discs treated with BMP2-transduced BMSCs exhibited relatively well-preserved nucleus pulposus (NP) structure. Significantly higher T2-weighted signal intensity and a greater amount of extracellular matrix were observed in the BMP2-transduced BMSC group compared with other groups. In addition, the presences of BMP2-transduced BMSCs were identified at week 12 postoperatively in vivo.
  
  
  
  BMP2-transduced BMSCs can maintain the chondrocyte-like phenotype in PRP gel in vitro, and the combined use of these two agents can significantly promote repair of the degenerated discs in vivo.
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Shi
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China. Alexzandersuper@163.com.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Shi
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China.
authors.forename: Guohua
authors.initials: G
authors.lastname: Xu
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Orthopaedic Department, Changzheng Hospital, Shanghai, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
mesh_terms: D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002454:Cell Differentiation; D019902:Chondrocytes / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D007150:Immunohistochemistry; D007403:Intervertebral Disc / Q000187:drug effects / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D053657:Platelet-Rich Plasma / Q000187:drug effects* / Q000378:metabolism; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055758:SOX9 Transcription Factor / Q000378:metabolism
chemical_list: D053674:Aggrecans; C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; D003094:Collagen
keywords: BMP2; BMSCs; Cell transplantation; Disc degeneration; Nucleus pulposus; PRP