Gene expressions dynamics in nerve regeneration after anterior cruciate ligament injury in a rat model

Introduction/Background The anterior cruciate ligament injury make difficulties in daily activity of daily living and sports. Even when the knee joint is operated a ligament reconstruction after injury, some patients complain of joint instability. It is thought that the nerve existing there is damaged when the ACL is damaged, and the nerve function is deteriorated. The purpose of this study was to evaluate nerve regeneration after ACL injury. Material and method Wistar male rats, aged 11 weeks, were randomly assigned to three groups, ACL transection (ACL-T; n  = 7), ACL transaction and controlling abnormal joint movement (CAJM: n  = 7), Sham op (Sham; n  = 7). ACLs were harvested at 4 weeks after surgery, evaluated PCR array analysis and the histologic sections using double immunofluorescence methods for primary antibodies Brain-derived neurotrophic factor (BDNF), neurofilament (NF). Secondary antibodies were used Dylight488 and Cy3. Results CAJM was above 2 folds more upregulated in 26 genes than in Sham, and below 2 folds downregulated in 15 genes. ACLT was above 2 folds more upregulated in 22 genes than in Sham, and below 2 folds downregulated in 21 genes. ACLT was above 2 folds more upregulated in 22 genes than in Sham, and below 2 folds downregulated in 21 genes. CAJM was above 2 folds more upregulated in 26 genes than in ACLT and below 2 folds downregulated in 17 genes in 4 weeks. In CAJM, NF positive nerves including BDNF were observed in the synovium, ligamentous bone attachment area, and NF positive nerves not containing BDNF were also observed in the ligament surface layer. Conclusion We reported that joint reaction caused by stability read to heal the injured ACL. Normalization of abnormal joint movement increases the expression of the neural plastic factor, and decreases that of apoptosis factor. These findings might have important consequences for neural plasticity and regeneration in the neuromuscular system in the knee deficiency.