Zeng Zhong, Li Mei, Jiang Zhanfeng, Lan Yuanxiang, Chen Lei, Chen Yanjun, Li Hailiang, Hui Jianwen, Zhang Lijian, Hu Xvlei, Xia Hechun
Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.
Ningxia Key Laboratory of Stem Cell and Regenerative Medicine, General Hospital of Ningxia Medical University, Yinchuan, China.
Front Neurosci. 2022 Nov 23;16:1066528. doi: 10.3389/fnins.2022.1066528. eCollection 2022.
Spinal cord injury (SCI) results in drastic dysregulation of microenvironmental metabolism during the acute phase, which greatly affects neural recovery. A better insight into the potential molecular pathways of metabolic dysregulation by multi-omics analysis could help to reveal targets that promote nerve repair and regeneration in the future.
We established the SCI model and rats were randomly divided into two groups: the acute-phase SCI (ASCI) group ( = 14, 3 days post-SCI) and the sham group with day-matched periods ( = 14, without SCI). In each group, rats were sacrificed at 3 days post-surgery for histology study ( = 3), metabolome sequencing ( = 5), transcriptome sequencing ( = 3), and quantitative real-time polymerase chain reaction ( = 3). The motor function of rats was evaluated by double-blind Basso, Beattie, and Bresnahan (BBB) Locomotor Scores at 0, 1, 2, 3 days post-SCI in an open field area. Then the transcriptomic and metabolomic data were integrated in SCI model of rat to reveal the underlying molecular pathways of microenvironmental metabolic dysregulation.
The histology of the microenvironment was significantly altered in ASCI and the locomotor function was significantly reduced in rats. Metabolomics analysis showed that 360 metabolites were highly altered during the acute phase of SCI, of which 310 were up-regulated and 50 were down-regulated, and bioinformatics analysis revealed that these differential metabolites were mainly enriched in arginine and proline metabolism, D-glutamine and D-glutamate metabolism, purine metabolism, biosynthesis of unsaturated fatty acids. Transcriptomics results showed that 5,963 genes were clearly altered, of which 2,848 genes were up-regulated and 3,115 genes were down-regulated, and these differentially expressed genes were mainly involved in response to stimulus, metabolic process, immune system process. Surprisingly, the Integrative analysis revealed significant dysregulation of purine metabolism at both transcriptome and metabolome levels in the acute phase of SCI, with 48 differential genes and 16 differential metabolites involved. Further analysis indicated that dysregulation of purine metabolism could seriously affect the energy metabolism of the injured microenvironment and increase oxidative stress as well as other responses detrimental to nerve repair and regeneration.
On the whole, we have for the first time combined transcriptomics and metabolomics to systematically analyze the potential molecular pathways of metabolic dysregulation in the acute phase of SCI, which will contribute to broaden our understanding of the sophisticated molecular mechanisms of SCI, in parallel with serving as a foundation for future studies of neural repair and regeneration after SCI.
脊髓损伤（SCI）在急性期会导致微环境代谢的剧烈失调，这对神经恢复有很大影响。通过多组学分析更好地了解代谢失调的潜在分子途径，有助于揭示未来促进神经修复和再生的靶点。
我们建立了SCI模型，将大鼠随机分为两组：急性期SCI（ASCI）组（n = 14，SCI后3天）和假手术组（n = 14，无SCI，与ASCI组时间匹配）。每组中，在术后3天处死大鼠进行组织学研究（n = 3）、代谢组测序（n = 5）、转录组测序（n = 3）和定量实时聚合酶链反应（n = 3）。在开放场地，于SCI后0、1、2、3天通过双盲Basso、Beattie和Bresnahan（BBB）运动评分评估大鼠的运动功能。然后将转录组和代谢组数据整合到大鼠SCI模型中，以揭示微环境代谢失调的潜在分子途径。
ASCI组微环境的组织学发生显著改变，大鼠的运动功能显著降低。代谢组学分析表明，SCI急性期有360种代谢物发生高度改变，其中310种上调，50种下调，生物信息学分析显示这些差异代谢物主要富集在精氨酸和脯氨酸代谢、D-谷氨酰胺和D-谷氨酸代谢、嘌呤代谢、不饱和脂肪酸生物合成中。转录组学结果显示，有5963个基因发生明显改变，其中2848个基因上调，3115个基因下调，这些差异表达基因主要参与对刺激的反应、代谢过程、免疫系统过程。令人惊讶的是，综合分析显示SCI急性期在转录组和代谢组水平上嘌呤代谢均存在显著失调，涉及48个差异基因和16个差异代谢物。进一步分析表明，嘌呤代谢失调会严重影响损伤微环境的能量代谢，并增加氧化应激以及其他对神经修复和再生有害的反应。
总体而言，我们首次将转录组学和代谢组学结合起来，系统地分析了SCI急性期代谢失调的潜在分子途径，这将有助于拓宽我们对SCI复杂分子机制的理解，同时为未来SCI后神经修复和再生的研究奠定基础。
