| Part I Expression of Bcl-2 and Bax proteins in the neurons of spinal cord segment after tibial nerve and common peroneal nerve injures and repairs in ratsObjective To research the expression levels of Bcl-2 and Bax proteins in the neurons of spinal cord segment after tibial nerve and common peroneal nerve transection and anastomosis in rats.Methods 90 male SD rats were randomly divided into the three groups:Group A:control group,Group B:tibial nerve transection and anastomosis,Group C:common peroneal nerve transection and anastomosis.The L4-6 spinal cord segment of rat was obtained at certain post-operatvie point of time for HE staining,also for Bcl-2 and Bax immumohistochemical analysis at 1,3,7,14,28 d after the operation.The cell numbers of motor neuron in the spinal anterior horn were calculated.The expression levels of Bcl-2 and Bax proteins were analyzed.Results There was no obvious abnormality happened in the spinal cord of group A compared to other two groups.While in group B and group C,there were pathological changes such as neuronal edma and necrosis happened in spinal cords.The overall post-operative recovery result of group B was better than that of group C in 14d and 28d after the operation.The expression level of Bcl-2 protein showed a curvilinear trend began with declining to the lowest levels and then upgrading.Specifically,the expression levels of Bcl-2 protein in group B and C were decreased to the lowest at the post-operative 3d and 7d respectively.In contrast,the expression levels of Bax protein in group B and C exhibited an upward and then declining trend.The ratios of Bcl-2/Bax in group B was decreased to the lowest at the postoperative 3 d.While the ratios in group C was decreased to the lowest at the postoperative 7d.The ratios of Bcl-2/Bax in group B and C were similar,which also suggesting that the smaller the Bcl-2/Bax ratio,the less the cell number of neurons,and more apoptotic cells.Conclusion The expression levels of Bcl-2 and Bax proteins in the corresponding spinal cord segment showed some differences between tibial nerve and common peroneal nerve after their injures.The Bcl-2/Bax ratio could be used to assess the apoptosis and regeneration of nerve after nerve injures.The recovery capability of corresponding spinal cord segment of tibial nerve was considered stronger than that of the common peroneal nerve,suggesting that the tibial nerve regeneration could be stronger than that of the common peroneal nerve.Part Ⅱ Differential gene and protein expression during Wallerian degeneration after tibial nerve and common peroneal nerve injury in ratsObjective Wallerian degeneration and nerve regeneration after injury are complex processes involving several cytokines,genes,and proteins.We studied the differences in gene and protein expression during Wallerian degeneration after injury of the tibial nerve and common peroneal nerve in rat models by using high-throughput transcriptome sequencing(RNA-seq)and proteomics techniques.Methods Sixteen male rats were randomly divided into 4 groups(4 rats/group),and subjected to same-level dissection and subsequent repairment of the tibial and common peroneal nerve.These rats were anesthetized again on days 1,7,14,and 21 after surgery and the distal nerves stumps of the tibial and common peroneal nerves(about 1 cm in length)were obtained.Results Of these tibial and common peroneal nerves,there were 1718,1374,1187,and 2195 differentially expressed genes,and 477,447,619,and 495 differentially expressed proteins on days 1,7,14,and 21 after surgery,respectively.Forty-seven pathways were activated in the process of Wallerian degeneration.Gene expression changes observed were consistent with RNA-seq and proteomics results.Conclusion We observed differential expression of genes and proteins in the distal nerve tissue during Wallerian degeneration,depending on the type of peripheral nerves,indicating that biological processes occurring during Wallerian degeneration after injury of different peripheral nerves are different. |
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