Optic nerve regeneration by overexpression of the microtubule regulator, SCG10 family

成年哺乳动物中枢神经系统神经元轴突损伤后难以再生。在这项研究中，为了促进轴突切除视网膜神经节细胞的轴突再生，我们研究了控制微管（MTs）基因强制表达的影响。我们选择SCG10作为MT控制蛋白的候选物。从以往的研究中得知，SCG10家族通过MTs的去聚肽化参与神经元细胞骨架的形成，并在神经元可塑性和轴突再生中发挥重要作用。本研究首先构建了特异性表达SCG10的病毒载体，并在体外将其感染到海马神经元中。尽管该基因被成功导入细胞，但通过SCG蛋白的过表达来评估，与未转染的对照神经元相比，神经元过程的长度和分支点的数量出乎意料地减少。由此可见，SCG10单独对神经元过程延伸具有抑制作用。然后，我们进一步研究了SCG10其他基因如MT控制蛋白、RB3、SCLIP和Stathmin的联合表达效果。然而，我们没有成功地检查这些SCG10样蛋白的联合作用。此外，我们试图从神经元凋亡被抑制的Bcl-2过度外排小鼠中分离视网膜神经节细胞。同样，我们没有成功地分离视网膜神经节细胞，不足以评估它们的存活能力和轴突再生能力。2004年，我们通过比较带n末端的全长RB3和不带n末端的截断RB3的效果，研究了是否有特定结构域的n末端有助于SCG10在MTs解聚中的功能。结果表明，n端结构域对mtts聚合的控制至关重要，因此SCG10家族通常可以通过n端结构域的控制区域来控制mtts的动力学，并通过该区域控制神经过程和神经形状。少

CNS neurons of adult mammals hardly regenerate after axonal damage. In this study, in order to promote axonal regeneration of axotomized retinal ganglion cells, we examined the effect of compulsory expression of genes that control microtubules (MTs). As a candidate of such MT controlling protein we chose SCG10. From previous studies SCG10 family is know to be involved in neuronal cytoskelton formation through depolinezatoin of MTs and it plays an important role in neuronal plasticity and axonal regeneration. Here we first constructed a virus vector which specifically expresses SCG10 and infected it into the hippocampal neurons in vitro. Although the gene was successfully introduced into the cells, as assessed by an over-expression of SCG protein, the length of neuronal process and the number of branching points were, unexpectedly reduced as compared with control untransfected neurons. This, it appears that SCG10 alone has suppressing effect for neuronal process extension. Then, we furt … More her tried to see the effect of combined expressions of other genes of SCG10 like MT controlling proteins, RB3, SCLIP and Stathmin. However, we did not succeed to examine the combined effects of these SCG10 like proteins. Furthermore, we tried to isolate retinal ganglion cells from Bcl-2 over-exoressed mice where neuronal apoptosis is inhibited. Again we did not succeed to isolate retinal ganglion cells enough to evaluate their survivability and capacity for axonal regeneration.In 2004 we examined whether or no N-terminals with specific domains that contribute to the SCG10's function in depolymerization of MTs by comparing the effect of full-length RB3 with N-terminals and truncated RB3 without such N-terminals. As a result we found that the N-terminal domain is essentially important for control of polymerization of MTs. Thus the SCG10 family in general may control the dynamics of MTs using controlling region of the N-terminal domain and through which neural processes and neural shapes may be controlled. Less