title: [Enhancement of meniscal tearing damage repairing in the avascular zone using connective tissue growth factor (CTGF) in the rabbit model].
abstract: OBJECTIVE
  To investigate effect of connective tissue growth factors (CTGF) on secretion of extracellular matrix synthesis of meniscal fibrochondrocytes, expression of vascular endothelial growth factors (VEGF), and angiogenesis during the repair of meniscal tearing damage.
  
  
  METHODS
  Meniscal fibrochondrocytes were isolated from the inner--1/2 of rabbits' meniscus by collagenase enzymatic digestion, centrifugal separation, and treated with 100 ng/ml CTGF in vitro. Characterization of fibrochondrocytes was identified by flow cytometry analysising CD31, CD44, CD45 and CD105, and was further tested by type II collagen immunocytochemistry. Changes in gene expression of meniscal fibrochondrocytes were monitored by quantitative real-time polymerase chain reaction. In vitro, the sections of the 3 mm of the longitudinal teared in the middle of the rabbit's meniscus, and then the defects were dealed with simple suture, suture and implanting with PBS-fibrin glue, sutured and implanting with 1.5 microg CTGF respectively. Expression and distribution of type I and II collagen and VEGF, the tearing healing were observed by fluorescence-immunohistochemisty analysis on the 1st week, the 4th week and the 10th week.
  
  
  RESULTS
  Quantitative RT-PCR assays showed that type I and type II collagen,and VEGF mRNA expression in the 100 ng/ml CTGF group had been remarkably enhanced than in the PBS group on the 14th day. Consistent with these effects in vitro, fluorescence-immunohistochemical analysis revealed that in the group implanted with CTGF-fibrin glue, type I collagen, type I collagen and capillaries completely filled the defect on the 10th week postoperatively. In contrast, only soft tissue repair occurred after the PBS-fibrin glue was implanted.
  
  
  CONCLUSIONS
  CTGF can significantly promote extracellular matrix (I collagen, II collagen) of the meniscal avascular zone synthesis, and CTGF can greatly heighten the expression of VEGF activity at the same time in vitro, so that it can further enhance the repair of meniscal tearing damage in the avascular zone.
authors.affiliation: Department of Orthopaedics, the 305th Hospital of People's Liberation Army, Beijing 100017, China.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.forename: Zu-Hong
authors.initials: ZH
authors.lastname: Qing
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Yu-Jie
authors.initials: YJ
authors.lastname: Liu
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Huang
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000235:genetics; D024043:Collagen Type II / Q000235:genetics; D055513:Connective Tissue Growth Factor / Q000627:therapeutic use*; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D011817:Rabbits; D000070600:Tibial Meniscus Injuries; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D014945:Wound Healing / Q000187:drug effects
chemical_list: D024042:Collagen Type I; D024043:Collagen Type II; D042461:Vascular Endothelial Growth Factor A; D055513:Connective Tissue Growth Factor