Axonal regeneration into acellular nerve grafts is enhanced by degradation of chondroitin sulfate proteoglycan
Axonal regeneration into acellular nerve grafts is enhanced by degradation of chondroitin sulfate proteoglycan
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DOI：
10.1523/jneurosci.21-16-06206.2001
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发表时间：
2001-08-15
影响因子：
5.3
通讯作者：
Muir, D
中科院分区：
文献类型：
--
作者：
Krekoski, CA;Neubauer, D;Muir, D
虽然周围神经损伤后有再生的潜力，退化过程可能是必不可少的，以促进轴突生长到失神经支配的神经。一种假设是，神经含有生长抑制剂，必须在损伤后中和以实现最佳再生。在本研究中，我们测试了硫酸软骨素蛋白聚糖（一种已知的轴突生长抑制剂）的降解是否增强了从正常供体神经制备的移植物的促生长特性。在用硫酸软骨素酶ABC处理之前，通过冷冻杀死使大鼠坐骨神经离体段脱细胞。软骨素酶依赖性新表位免疫标记显示，硫酸软骨素蛋白聚糖在整个治疗的神经节段被彻底降解。此外，神经元冷冻培养试验表明，软骨素酶处理的无细胞神经的促轴突生长活性显着增加。然后将对照和软骨素酶处理的脱细胞神经用作大鼠神经损伤模型中的间置移植物。植入后4和8天，通过生长相关蛋白-43免疫标记评估移植物的轴突再生。在这两个时间点，再生成软骨素酶处理的无细胞移植物的轴突数是对照移植物的几倍。生长到软骨素酶处理的移植物后，只有4天明显，这表明轴突生长的延迟通常与脱细胞移植物被衰减以及。这些发现表明，软骨素酶处理显着增强了冷冻灭活供体神经移植物的促生长特性。结合无细胞移植物的低免疫原性，通过术前用软骨素酶处理来改善轴突穿透到间置移植物中的能力可能是临床神经同种异体移植的显著进步。
Although the peripheral nerve has the potential to regenerate after injury, degenerative processes may be essential to promote axonal growth into the denervated nerve. One hypothesis is that the nerve contains growth inhibitors that must be neutralized after injury for optimal regeneration. In the present study, we tested whether degradation of chondroitin sulfate proteoglycan, a known inhibitor of axon growth, enhances the growth-promoting properties of grafts prepared from normal donor nerves. Excised segments of rat sciatic nerve were made acellular by freeze-killing before treatment with chondroitinase ABC. Chondroitinase-dependent neoepitope immunolabeling showed that chondroitin sulfate proteoglycan was thoroughly degraded throughout the treated nerve segments. In addition, neuronal cryoculture assays revealed that the neurite-promoting activity of acellular nerves was significantly increased by chondroitinase treatment. Control and chondroitinase-treated acellular nerves were then used as interpositional grafts in a rat nerve injury model. Axonal regeneration into the grafts was assessed 4 and 8 d after implantation by growth-associated protein-43 immunolabeling. At both time points, the number of axons regenerating into acellular grafts treated with chondroitinase was severalfold greater than in control grafts. Growth into the chondroitinase-treated grafts was pronounced after only 4 d, suggesting that the delay of axonal growth normally associated with acellular grafts was attenuated as well. These findings indicate that chondroitinase treatment significantly enhanced the growth-promoting properties of freeze-killed donor nerve grafts. Combined with the low immunogenicity of acellular grafts, the ability to improve axonal penetration into interpositional grafts by preoperative treatment with chondroitinase may be a significant advancement for clinical nerve allografting.