Feng Sa, Liu Linyan, Cheng Yuelin, Zhou Mengmeng, Zhu Haoqiang, Zhao Xinyan, Chen Ziyu, Kan Shunli, Fu Xuanhao, Hu Wei, Zhu Rusen
Department of Spine Surgery, Tianjin Union Medical Center, Tianjin Medical University, Tianjin, China.
Tianjin Institute of Spinal Surgery, Tianjin Union Medical Center, Tianjin, China.
Front Pharmacol. 2024 Oct 8;15:1434652. doi: 10.3389/fphar.2024.1434652. eCollection 2024.
The limited ability to regenerate axons after spinal cord injury (SCI) is influenced by factors such as astrocyte activation, reactive proliferation, and glial scar formation. The TGF-β/Smad (transforming growth factor-β/mothers against decapentaplegic homolog) pathway, associated with astrocytic scarring, plays a crucial role in recovery post-injury. This study aims to investigate how icariin (ICA) interacts with reactive astrocytes in the treatment of spinal cord injury.
A rat SCI model was constructed, and the recovery of motor function was observed after treatment with ICA.HE staining, LFB staining, immunofluorescence staining, and Western blotting were employed to assess ICA's ability to inhibit astrocyte proliferation in rats following spinal cord injury by modulating YAP, as well as to evaluate the reparative effects of ICA on the injured spinal cord tissue. Primary astrocytes were isolated and cultured. Immunoprecipitation-Western Blot (IP-WB) ubiquitination and cytoplasm-nuclear separation were employed to assess PPM1B ubiquitination and nuclear translocation.
The CatWalk XT gait analysis, BBB (Basso, Beattie, and Bresnahan) score, electrophysiological measurements, HE staining, and LFB staining collectively demonstrated that ICA promotes motor function and tissue recovery following spinal cord injury in rats. Immunofluorescence staining and Western Blot analyses revealed that ICA inhibits astrocyte proliferation in rats post-spinal cord injury by suppressing YAP activity. Furthermore, the activation of YAP by XMU-MP-1 was shown to compromise the efficacy of ICA in these rats after spinal cord injury. Additional immunofluorescence staining and Western Blot experiments confirmed that ICA inhibits TGFβ1-induced astrocyte activation through the regulation of YAP. The knockdown of PPM1B (protein phosphatase, Mg2+/Mn2+-dependent 1B) in astrocytes was found to inhibit TGFβ signaling. Additionally, YAP was shown to regulate PPM1B ubiquitination and nuclear translocation through immunoprecipitation-Western blot analysis, along with the segregation of cytoplasm and nucleus.
Icariin promotes functional recovery in rats after spinal cord injury by inhibiting YAP and regulating PPM1B ubiquitination to inhibiting the activation of reactive astrocytes.
脊髓损伤（SCI）后轴突再生能力有限，受星形胶质细胞激活、反应性增殖和胶质瘢痕形成等因素影响。与星形胶质细胞瘢痕形成相关的转化生长因子-β/ 母系对抗五肢瘫同源物（TGF-β/Smad）信号通路在损伤后恢复中起关键作用。本研究旨在探讨淫羊藿苷（ICA）在脊髓损伤治疗中如何与反应性星形胶质细胞相互作用。
构建大鼠SCI模型，观察ICA治疗后运动功能的恢复情况。采用苏木精-伊红（HE）染色、丽春红染色（LFB）、免疫荧光染色和蛋白质印迹法，评估ICA通过调节Yes相关蛋白（YAP）抑制脊髓损伤大鼠星形胶质细胞增殖的能力，以及评估ICA对损伤脊髓组织的修复作用。分离并培养原代星形胶质细胞。采用免疫沉淀-蛋白质印迹（IP-WB）泛素化和细胞质-细胞核分离法，评估丝氨酸/苏氨酸蛋白磷酸酶1B（PPM1B）的泛素化和核转位。
CatWalk XT步态分析、Basso、Beattie和Bresnahan（BBB）评分、电生理测量、HE染色和LFB染色共同表明，ICA促进大鼠脊髓损伤后的运动功能和组织恢复。免疫荧光染色和蛋白质印迹分析显示，ICA通过抑制YAP活性抑制大鼠脊髓损伤后的星形胶质细胞增殖。此外，XMU-MP-1激活YAP会损害ICA对这些脊髓损伤大鼠的疗效。额外的免疫荧光染色和蛋白质印迹实验证实，ICA通过调节YAP抑制转化生长因子β1（TGFβ1）诱导的星形胶质细胞激活。发现星形胶质细胞中PPM1B（蛋白磷酸酶，Mg2+/Mn2+依赖1B）的敲低会抑制TGFβ信号传导。此外，通过免疫沉淀-蛋白质印迹分析以及细胞质和细胞核的分离，YAP被证明可调节PPM1B的泛素化和核转位。
淫羊藿苷通过抑制YAP和调节PPM1B泛素化以抑制反应性星形胶质细胞的激活，促进大鼠脊髓损伤后的功能恢复。
