Rapamycin, similar to FK506, can promote neural regeneration in vitro. We assumed that the mechanisms of action of rapamycin and FK506 in promoting peripheral nerve regeneration were similar. This study compared the effects of different concentrations of rapamycin and FK506 on Sc hwann cells and investigated effects and mechanisms of rapamycin on improving peripheral nerve regeneration. Results demonstrated that the lowest rapamycin concentration (1.53 nmol/L) more signiifcantly promoted Schwann cell migration than the highest FK506 concentration (100μmol/L). Rapamycin promoted the secretion of nerve growth factors and upregulated growth-associated protein 43 expression in Schwann cells, but did not signiifcantly affect Schwann cell proliferation. Therefore, rapamycin has potential application in peripheral nerve regeneration therapy.

Claudin 14 has been shown to promote nerve repair and regeneration in the early stages of Wallerian degeneration (0–4 days) in rats with sciatic nerve injury, but the mechanism under-lying this process remains poorly understood. This study reported the effects of claudin 14 on nerve degeneration and regeneration during early Wallerian degeneration. Claudin 14 expression was up-regulated in sciatic nerve 4 days after Wallerian degeneration. The altered expression of claudin 14 in Schwann cells resulted in expression changes of cytokines in vitro. Expression of claudin 14 affected c-Jun, but not Akt and ERK1/2 pathways. Further studies revealed that enhanced expression of claudin 14 could promote Schwann cell proliferation and migration. Silencing of claudin 14 expression resulted in Schwann cell apoptosis and reduction in Schwann cell proliferation. Our data revealed the role of claudin 14 in early Wallerian degeneration, which may provide new insights into the molecular mechanisms of Wallerian degeneration.

Injuries to peripheral nerves are common and cause life-changing problems for patients along-side high social and health care costs for society. Current clinical treatment of peripheral nerve injuries predominantly relies on sacriifcing a section of nerve from elsewhere in the body to pro-vide a graft at the injury site. Much work has been done to develop a bioengineered nerve graft, precluding sacriifce of a functional nerve. Stem cells are prime candidates as accelerators of re-generation in these nerve grafts. This review examines the potential of adipose-derived stem cells to improve nerve repair assisted by bioengineered nerve grafts.

pSVPoMCAT微基因修饰雪旺氏细胞移植治疗实验性脊髓损伤的酶及免疫组化评价

Objective To investigate the effect of microgene pSVPoMcat to modify genetically Schwann cell(SC) on recovery of function after spinal cord injury(SCI).Methods Experimental animals were divided into three groups:the group of microgene pSVPoMcat implanted to genetically(group A),SC implanted group(group B),and the control group(group C),each group having 10 animals.The cortical somatasensory evoked potentials(CSEP) and combined behavioral score(CBS) were continually monitored from operation second week to twelfth week.We used image analysis system to compare the latent period and peak amplitudes of CSEP and count the axon number among the different group.At the same time,electron microscope obsevation was conducted.Results The peak latency and amplitudes of group A,B showed a recovery tendency and it was constant with CBS.The number of regenerated axons of the group A and group B were (388± 163) and (109± 16),respectively(P < 0.01),in line with the observation of electron microscope.Conclusion We conclude that microgene pSVPoMcat to modify genetically SC plays a promoting role in recovery of central function after SCI.

pSVPoMcat微基因修饰雪旺细胞脊髓内移植对操作脊髓再生的影响

Objective In order to observe the role of genetically modified Schwann cell (SC) with pSVPoMcat in the regeneration of injured spinal cord.Method The cells were implanted into the spinal cord.Ninety SD rats were used to establish a model of hemi- transection of spinal cord at the level of T8,and were divided into three groups,randomly, that is,pSVPoMcat modified SC implantation(Group A), SC implantation(Group B),and without cell implantation as control(Group C).After three months the presence of axonal regeneration of the injured spinal cord was examined by means of horseradish peroxidase(HRP)retrograde labeling technique and stereography.Result The results indicated that HRP labeled cells in Group A and B could be found in the superior region of injured spinal cord and the brain stem such as the red nuclei and oculomotor nuclei. The density of ventral horn neurons of the spinal cord and the number of myelinated axons in 100 μ m of the white matter was A >B >C group.Conclusion In brief,the pSVPoMcat modified SC intraspinal implantation could promote regeneration of the injured spinal cord.

微基因修饰雪旺氏细胞移植对大鼠脊髓损伤后GAP－43表达的影响

Objective To study the effect of microgene pSVPoMcat implanted to modify schwann cell on growth associated protein－43(GAP－43) expression after spinal cord injury in adult rats.Method Hemisected of the T8 segment of the spinal cord was performed for all the experiment rats.The rats were randomly divided into three groups as follows:Group A with microgene pSVPoMcat implanted to genetically modify SC;Group B with SC implanted ;Group C with hemisection of the spinal cord only.The changes of expression of GAP－43 in spinal cord were observed by immunochemistry with antibodies against GAP－43 .Simultaneous,the combined behavioral scores(CBS)was measured.Result There were not any different(P >0.05)among the three groups in first week and 12 week.There were significant diffeence(P<0.05)among three groups in 2nd,8th,and more dxpression of GAP－43 at the 2nd week in group A.The neurofunctional recovery was best in group A.Conclusion The microgene pSVPoMcat implanted to modify schwann cell can promote the expression of GAP－43 in spinal cord and functional recovery in adults rats after SCI.

微基因修饰雪旺氏细胞移植对大鼠脊髓损伤后GAP－43表达的影响

Objective To study the effect of microgene pSVPoMcat implanted to modify schwann cell on growth associated protein－43(GAP－43) expression after spinal cord injury in adult rats.Method Hemisected of the T8 segment of the spinal cord was performed for all the experiment rats.The rats were randomly divided into three groups as follows:Group A with microgene pSVPoMcat implanted to genetically modify SC;Group B with SC implanted ;Group C with hemisection of the spinal cord only.The changes of expression of GAP－43 in spinal cord were observed by immunochemistry with antibodies against GAP－43 .Simultaneous,the combined behavioral scores(CBS)was measured.Result There were not any different(P >0.05)among the three groups in first week and 12 week.There were significant diffeence(P<0.05)among three groups in 2nd,8th,and more dxpression of GAP－43 at the 2nd week in group A.The neurofunctional recovery was best in group A.Conclusion The microgene pSVPoMcat implanted to modify schwann cell can promote the expression of GAP－43 in spinal cord and functional recovery in adults rats after SCI.

应用MRI和电镜观察pSVPoMact微基因修饰雪氏细胞移植对损伤脊髓的修复作用

Objective To approach the effect of microgene pSVPoMcat modified Schwann cell (SC) on the regeneration and repair of injured spinal cord.Method Spinal cord hemi－ transection models were made with the cutting method in healthy SD rats. Microgene pSVPoMcat modified SC(group A),highly purified SC(group B),and glutin sponge (control group C)were randomly implanted into the cut. After 3 month living ,the host rats were scanned by MRI, and observed under EM. Result Spinal signals at the injury region nearly recovered to normal in group A.No recovery was found in group B.Malacosis was found in group C.TEM findings: regeneration of large number of myelinated and nonmyelinated axons and SC proliferation in group A, myelinated axon regeneration and SC necrosis in group B, non myelinated and nonmyelinated axon in group C.Conclusion Implantation of microgene pSVPoMcat modified SC could promote the repair of injured spinal cord.