Mathews G A, Ffrench-Constant C
Wellcome/CRC Institute of Cancer and Developmental Biology, University of Cambridge, United Kingdom.
J Neurobiol. 1995 Feb;26(2):171-88. doi: 10.1002/neu.480260203.
Fibronectin mRNAs that include the alternatively spliced exons EIIIA, EIIIB, and V are prevalent during embryogenesis, and EIIIA and EIIIB reappear during wound healing. Using ribonuclease protection analyses, we found an up-regulation of V120 (containing the alpha 4 beta 1 integrin binding site), as well as EIIIA, and EIIIB in fibronectin mRNAs in the crush-injured adult rat sciatic nerve. In situ hybridization using splice variant-specific probes revealed that cells within endoneurial tubes of the injured nerve synthesize these embryonic forms of fibronectin. Our results suggest that embryonic fibronectins synthesized within the nerve contribute to the permissiveness of the peripheral nervous system to axon regrowth and a mechanism by which alternative splicing of the V region in fibronectin mRNA could enhance nervous system regeneration.
包含选择性剪接外显子EIIIA、EIIIB和V的纤连蛋白mRNA在胚胎发育过程中普遍存在，并且EIIIA和EIIIB在伤口愈合期间重新出现。使用核糖核酸酶保护分析，我们发现挤压损伤的成年大鼠坐骨神经中纤连蛋白mRNA的V120（包含α4β1整合素结合位点）以及EIIIA和EIIIB上调。使用剪接变体特异性探针进行原位杂交显示，受损神经的神经内膜管内的细胞合成这些胚胎形式的纤连蛋白。我们的结果表明，神经内合成的胚胎纤连蛋白有助于外周神经系统对轴突再生的允许性，以及纤连蛋白mRNA中V区域的选择性剪接可增强神经系统再生的机制。
