Zi-Yuan Zhang, Zhao-Yang Zuo, Yang Liang, Si-Ming Zhang, Chun-Xia Zhang, Jing Chi, Bin Fan, Guang-Yu Li
{"title":"Promotion of axon regeneration and protection on injured retinal ganglion cells by rCXCL2.","authors":"Zi-Yuan Zhang, Zhao-Yang Zuo, Yang Liang, Si-Ming Zhang, Chun-Xia Zhang, Jing Chi, Bin Fan, Guang-Yu Li","doi":"10.1186/s41232-023-00283-5","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>In addition to rescuing injured retinal ganglion cells (RGCs) by stimulating the intrinsic growth ability of damaged RGCs in various retinal/optic neuropathies, increasing evidence has shown that the external microenvironmental factors also play a crucial role in restoring the survival of RGCs by promoting the regrowth of RGC axons, especially inflammatory factors. In this study, we aimed to screen out the underlying inflammatory factor involved in the signaling of staurosporine (STS)-induced axon regeneration and verify its role in the protection of RGCs and the promotion of axon regrowth.</p><p><strong>Methods: </strong>We performed transcriptome RNA sequencing for STS induction models in vitro and analyzed the differentially expressed genes. After targeting the key gene, we verified the role of the candidate factor in RGC protection and promotion of axon regeneration in vivo with two RGC-injured animal models (optic nerve crush, ONC; retinal N-methyl-D-aspartate, NMDA damage) by using cholera toxin subunit B anterograde axon tracing and specific immunostaining of RGCs.</p><p><strong>Results: </strong>We found that a series of inflammatory genes expressed upregulated in the signaling of STS-induced axon regrowth and we targeted the candidate CXCL2 gene since the level of the chemokine CXCL2 gene elevated significantly among the top upregulated genes. We further demonstrated that intravitreal injection of rCXCL2 robustly promoted axon regeneration and significantly improved RGC survival in ONC-injured mice in vivo. However, different from its role in ONC model, the intravitreal injection of rCXCL2 was able to simply protect RGCs against NMDA-induced excitotoxicity in mouse retina and maintain the long-distance projection of RGC axons, yet failed to promote significant axon regeneration.</p><p><strong>Conclusions: </strong>We provide the first in vivo evidence that CXCL2, as an inflammatory factor, is a key regulator in the axon regeneration and neuroprotection of RGCs. Our comparative study may facilitate deciphering the exact molecular mechanisms of RGC axon regeneration and developing high-potency targeted drugs.</p>","PeriodicalId":13588,"journal":{"name":"Inflammation and Regeneration","volume":"43 1","pages":"31"},"PeriodicalIF":5.0000,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10280836/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inflammation and Regeneration","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s41232-023-00283-5","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: In addition to rescuing injured retinal ganglion cells (RGCs) by stimulating the intrinsic growth ability of damaged RGCs in various retinal/optic neuropathies, increasing evidence has shown that the external microenvironmental factors also play a crucial role in restoring the survival of RGCs by promoting the regrowth of RGC axons, especially inflammatory factors. In this study, we aimed to screen out the underlying inflammatory factor involved in the signaling of staurosporine (STS)-induced axon regeneration and verify its role in the protection of RGCs and the promotion of axon regrowth.
Methods: We performed transcriptome RNA sequencing for STS induction models in vitro and analyzed the differentially expressed genes. After targeting the key gene, we verified the role of the candidate factor in RGC protection and promotion of axon regeneration in vivo with two RGC-injured animal models (optic nerve crush, ONC; retinal N-methyl-D-aspartate, NMDA damage) by using cholera toxin subunit B anterograde axon tracing and specific immunostaining of RGCs.
Results: We found that a series of inflammatory genes expressed upregulated in the signaling of STS-induced axon regrowth and we targeted the candidate CXCL2 gene since the level of the chemokine CXCL2 gene elevated significantly among the top upregulated genes. We further demonstrated that intravitreal injection of rCXCL2 robustly promoted axon regeneration and significantly improved RGC survival in ONC-injured mice in vivo. However, different from its role in ONC model, the intravitreal injection of rCXCL2 was able to simply protect RGCs against NMDA-induced excitotoxicity in mouse retina and maintain the long-distance projection of RGC axons, yet failed to promote significant axon regeneration.
Conclusions: We provide the first in vivo evidence that CXCL2, as an inflammatory factor, is a key regulator in the axon regeneration and neuroprotection of RGCs. Our comparative study may facilitate deciphering the exact molecular mechanisms of RGC axon regeneration and developing high-potency targeted drugs.
背景:在各种视网膜/视神经病变中,除了通过刺激受损视网膜神经节细胞(RGCs)的内在生长能力来挽救受损视网膜神经节细胞(RGCs)外,越来越多的证据表明,外部微环境因素,尤其是炎症因素,通过促进RGC轴突的再生,在恢复RGCs的存活中也起着至关重要的作用。在本研究中,我们旨在筛选staurosporine (STS)诱导的轴突再生信号通路中潜在的炎症因子,并验证其在保护rgc和促进轴突再生中的作用。方法:对体外STS诱导模型进行转录组RNA测序,分析差异表达基因。在靶向关键基因后,我们通过两种RGC损伤动物模型(视神经挤压,ONC;采用霍乱毒素亚基B顺行轴突示踪和RGCs特异性免疫染色法检测视网膜n -甲基- d -天冬氨酸(NMDA)损伤。结果:我们发现在sts诱导的轴突再生信号通路中,一系列炎症基因表达上调,由于趋化因子CXCL2基因在上调最高的基因中水平显著升高,我们将候选CXCL2基因作为目标。我们进一步证明,在onc损伤小鼠体内,玻璃体内注射rCXCL2可显著促进轴突再生,并显著提高RGC存活。然而,与其在ONC模型中的作用不同,rCXCL2玻璃体内注射仅能保护RGC免受nmda诱导的小鼠视网膜兴奋性毒性,维持RGC轴突的远距离投射,而不能显著促进轴突再生。结论:我们提供了第一个体内证据,证明CXCL2作为一种炎症因子,是RGCs轴突再生和神经保护的关键调节因子。我们的对比研究可能有助于破译RGC轴突再生的确切分子机制和开发高效靶向药物。
期刊介绍:
Inflammation and Regeneration is the official journal of the Japanese Society of Inflammation and Regeneration (JSIR). This journal provides an open access forum which covers a wide range of scientific topics in the basic and clinical researches on inflammation and regenerative medicine. It also covers investigations of infectious diseases, including COVID-19 and other emerging infectious diseases, which involve the inflammatory responses.
Inflammation and Regeneration publishes papers in the following categories: research article, note, rapid communication, case report, review and clinical drug evaluation.