Spreyer P, Kuhn G, Hanemann C O, Gillen C, Schaal H, Kuhn R, Lemke G, Müller H W
Department of Neurology, University of Düsseldorf, FRG.
EMBO J. 1991 Dec;10(12):3661-8. doi: 10.1002/j.1460-2075.1991.tb04933.x.
We have isolated a 1.8 kb cDNA (pCD25) clone that encodes a transcript that is differentially expressed during nerve regeneration. Nucleotide sequence comparison indicates 89.6% homology with the recently identified murine 'growth arrest-specific' gene gas3. The open reading frame of the CD25 transcript predicts a 17 kDa protein with four putative transmembrane regions. Steady-state levels of the CD25 mRNA are very much higher in sciatic nerve than in other tissues, and expression in sciatic nerve is confined to Schwann cells. Following nerve injury, the transcript levels rapidly declined in nerve segments distal to the site of lesion, but recovered upon nerve regeneration. In contrast, in distal stumps of permanently transected nerves, the mRNA level remained very low. Substantial amounts of the mRNA could be reinduced only upon anastomosis of these interrupted nerve stumps. Re-induction of the mRNA followed the elongation of regenerating axons through the distal nerve segment. Our data indicate that axons regulate expression of the CD25 mRNA in Schwann cells, and suggest that the CD25 protein functions during Schwann cell growth and differentiation.
我们分离出了一个1.8kb的cDNA（pCD25）克隆，它编码一种在神经再生过程中差异表达的转录本。核苷酸序列比较表明，它与最近鉴定的小鼠“生长停滞特异性”基因gas3有89.6%的同源性。CD25转录本的开放阅读框预测有一个17kDa的蛋白质，带有四个假定的跨膜区域。CD25 mRNA的稳态水平在坐骨神经中比在其他组织中高得多，并且在坐骨神经中的表达仅限于施万细胞。神经损伤后，损伤部位远端神经段的转录本水平迅速下降，但在神经再生时恢复。相比之下，在永久性横断神经的远端残端中，mRNA水平仍然很低。只有在这些中断的神经残端吻合后，大量的mRNA才能被重新诱导。mRNA的重新诱导跟随再生轴突通过远端神经段的延伸。我们的数据表明轴突调节施万细胞中CD25 mRNA的表达，并提示CD25蛋白在施万细胞生长和分化过程中发挥作用。
