Study Of HNT-3 Gene Transfection In Tendon Grafts Used In Rabbit Anterior Cruciate Ligament Reconstruction

Objective:To investigate the effect of adenovirus-mediated hNT-3 gene transfection on the regeneration of tendon graft proprioceptor after reconstruction of the anterior cruciate ligament in rabbits,and the expression of hNT-3 gene in tendon graft after transfection.Methods: Japanese white rabbits were randomly divided into three groups,and the animal model of autologous semitendinosus tendon transplantation was made after anterior cruciate ligament injury.Group A and B were respectively injected with Ad hNT-3 and Ad GFP,while group C were injected with saline as the control.Frozen sections of tendon grafts were taken from each group 48 h after surgery,and the expression of green fluorescent protein was observed by fluorescence microscopy.At the 8,16 and 24 weeks postoperatively,specimens were examined with immunohistochemical staining and HE staining in order to find proprioceptors.At 2 weeks,4 weeks,6 weeks and 8 weeks after the operation,specimens from each group were collected for western-blot and PCR detection to observe the expression of hNT-3.Results: In group A and B,Green fluorescent protein expression was found by the fluorescence microscope,but no expression was observed in group C.The number of mechanreceptors in group A,B and C increased with the extension of postoperative recovery time;At the same time point,the number of proprioceptors in group A was more than that in group B and C,and the difference was statistically significant(P<0.05).Western Blot showed that the expression level of NT-3 in group A was higher than that in group B and group C at different time points and the expression level of NT-3 in each group decreased gradually with the passage of time after surgery,and the difference was statistically significant(P<0.05).In addition,PCR showed that the expression of hNT-3 mRNA in group A decreased gradually and could be detected till the 8w after surgery,and the difference was statistically significant(P<0.05).However,no hNT-3 mRNA expression was found in group B and group C.Conclusion: Adenovirus-mediated transfection of hNT-3 gene could promote the regeneration of proprioceptor in autologous tendon graft after anterior cruciate ligament reconstruction,and the expression of hNT-3 gene in tendon graft can be sustained at least 8 weeks.