Functional change and significance of vertebral growth plate chondrocytes in patients with scoliosis secondary to type 1 neurofibromatosis

English Keywords:Neurofibromatoses  Scoliosis  Dystrophia  Neurofibromin  Chondrocyte

English Abstract:

  【Abstract】 Objective：To investigate the biological features of the chondrocytes isolated from vertebral growth plate in patients with type 1 neurofibromatosis（NF1） and its role in the dystrophic change of vertebrae.Method：This study included 8 cases of NF1 complicated with dystrophic scoliosis.There were 5 boys and 3 girls，aged from 9 to 15 years（mean 11.8±2.0 years）.Growth plates of dystrophic vertebrae（group A） and non-dystrophic vertebrae（group B） were harvested during anterior surgery，and iliac growth plate （group C） was harvested during posterior surgery.Chondrocytes from growth plate were isolated and cultured by two-step enzymatic digestion and tissue culture system in vitro.Expressions mRNA of aggrecan and type Ⅱ collagen as well as neurofibromin were assayed in P2 chondrocytes by Real-time PCR.Result：Expression mRNA of aggrecan was significantly lower in chondrocytes of group A（0.04±0.02） than the other two groups（0.09±0.04，0.13±0.07 respectively）（P<0.05）.The level of type Ⅱ collagen in group A（0.91±0.04） was significantly lower than group C（1.03±0.10）（P<0.05），yet not significantly lower than group B（0.96±0.07）（P>0.05）.Also，lower level of neurofibromin was detected in group A（0.39±0.30） compared with group B（1.34±0.63） and C（1.00±0.51）（P<0.05）.Each parameter showed no difference between group B and C（P>0.05）.Conclusion：Dysfunction of vertebral growth plate chondrocytes may contribute to the dystrophic change of vertebrae in scoliosis associated with NF1.