日本庆应义塾大学教授冈野荣之率领的研究小组最新发现，一种化合物能促进被切断的角膜感觉神经再生。研究报告发表在报告在新一期《科学公共图书馆综合卷》。

　　角膜有丰富的感觉神经，但在近视矫正、角膜移植等手术中，感觉神经可能被切断，感染也可能破坏神经，损害患者的视力。通常感觉神经再生需要数个月至一两年左右时间，促进神经再生则能改善症状。

　　研究小组注意到，一种称为“臂板蛋白3A”（sema3A）的蛋白质会遏制神经生长。他们从土壤的霉菌中提取出能抑制这种蛋白质功能的化合物SM－345431，给移植角膜的实验鼠注射。约3周后检查发现，角膜的感觉神经已经再生，而对照组的实验鼠则没有这种现象。

　　目前，研究人员正在使用诱导多功能干细胞（iPS细胞）等研究实现角膜的再生，而要想使移植的角膜发挥功用，就必须使神经再生。冈野等人研究小组指出：“这种化合物将来有可能作为治疗药物，提高角膜移植的成功率，从而有助于对角膜手术的术后管理。”

　　相关链接：The Semaphorin 3A Inhibitor SM-345431 Accelerates Peripheral Nerve Regeneration and Sensitivity in a Murine Corneal Transplantation Model

      The Semaphorin 3A Inhibitor SM-345431 Accelerates Peripheral Nerve Regeneration and Sensitivity in a Murine Corneal Transplantation Model

      Abstract
      Background
      Peripheral nerve damage of the cornea is a complication following surgery or infection which may lead to decreased visual function. We examined the efficacy of the semaphorin 3A inhibitor, SM-345431, in promoting regeneration of peripheral nerves in a mouse corneal transplantation model.

      Methodology/Principal Findings
      P0-Cre/Floxed-EGFP mice which express EGFP in peripheral nerves cells were used as recipients of corneal transplantation with syngeneic wild-type mouse cornea donors. SM-345431 was administered subconjunctivally every 2 days while control mice received vehicle only. Mice were followed for 3 weeks and the length of regenerating nerves was measured by EGFP fluorescence and immunohistochemistry against βIII tubulin. Cornea sensitivity was also measured by the Cochet-Bonnet esthesiometer. CD31 staining was used to determine corneal neovascularization as a possible side effect of SM-345431. Regeneration of βIII tubulin positive peripheral nerves was significantly higher in SM-345431 treated mice compared to control. Furthermore, corneal sensitivity significantly improved in the SM-345431 group by 3 weeks after transplantation. Neovascularization was limited to the peripheral cornea with no difference between SM-345431 group and control.

     Conclusions/Significance
     Subconjunctival injections of SM-345431 promoted a robust network of regenerating nerves as well as functional recovery of corneal sensation in a mouse keratoplasty model, suggesting a novel therapeutic strategy for treating neurotrophic corneal disease.