Zhang Feng-Ming, Wang Bing, Hu Han, Li Qing-Yi, Chen Hao-Hao, Luo Li-Ting, Jiang Zuo-Jie, Zeng Mei-Xing, Liu Xing-Jun
School of Pharmacy, Nantong University, Nantong, Jiangsu Province, 226001, China.
Department of Anesthesiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, 210029, China.
Endocr Metab Immune Disord Drug Targets. 2023;23(3):375-388. doi: 10.2174/1871530322666221006114557.
Neuroinflammation and cytokines play critical roles in neuropathic pain and axon degeneration/regeneration. Cytokines of transforming growth factor-β superfamily have implications in pain and injured nerve repair processing. However, the transcriptional profiles of the transforming growth factor-β superfamily members in dorsal root ganglia under neuropathic pain and axon degeneration/regeneration conditions remain elusive.
We aimed to plot the transcriptional profiles of transforming growth factor-β superfamily components in lumbar dorsal root ganglia of sciatic nerve-axotomized rats and to further verify the profiles by testing the analgesic effect of activin C, a representative cytokine, on neuropathic pain.
Adult male rats were axotomized in sciatic nerves, and lumbar dorsal root ganglia were isolated for total RNA extraction or section. A custom microarray was developed and employed to plot the gene expression profiles of transforming growth factor-β superfamily components. Realtime RT-PCR was used to confirm changes in the expression of activin/inhibin family genes, and then in situ hybridization was performed to determine the cellular locations of inhibin α, activin βC, BMP-5 and GDF-9 mRNAs. The rat spared nerve injury model was performed, and a pain test was employed to determine the effect of activin C on neuropathic pain.
The expression of transforming growth factor-β superfamily cytokines and their signaling, including some receptors and signaling adaptors, were robustly upregulated. Activin βC subunit mRNAs were expressed in the small-diameter dorsal root ganglion neurons and upregulated after axotomy. Single intrathecal injection of activin C inhibited neuropathic pain in spared nerve injury model.
This is the first report to investigate the transcriptional profiles of members of transforming growth factor-β superfamily in axotomized dorsal root ganglia. The distinct cytokine profiles observed here might provide clues toward further study of the role of transforming growth factor-β superfamily in the pathogenesis of neuropathic pain and axon degeneration/regeneration after peripheral nerve injury.
神经炎症和细胞因子在神经性疼痛以及轴突退变/再生过程中发挥着关键作用。转化生长因子-β超家族的细胞因子与疼痛及受损神经的修复过程相关。然而，在神经性疼痛和轴突退变/再生条件下，背根神经节中转化生长因子-β超家族成员的转录谱仍不清楚。
我们旨在描绘坐骨神经切断大鼠腰段背根神经节中转化生长因子-β超家族成分的转录谱，并通过检测代表性细胞因子激活素C对神经性疼痛的镇痛作用来进一步验证该转录谱。
成年雄性大鼠坐骨神经被切断，分离腰段背根神经节用于提取总RNA或切片。开发并使用定制的微阵列来描绘转化生长因子-β超家族成分的基因表达谱。采用实时逆转录聚合酶链反应来确认激活素/抑制素家族基因表达的变化，然后进行原位杂交以确定抑制素α、激活素βC、骨形态发生蛋白-5和生长分化因子-9信使核糖核酸的细胞定位。建立大鼠保留神经损伤模型，并采用疼痛测试来确定激活素C对神经性疼痛的影响。
转化生长因子-β超家族细胞因子及其信号传导，包括一些受体和信号衔接分子的表达均显著上调。激活素βC亚基信使核糖核酸在小直径背根神经节神经元中表达，切断轴突后上调。在保留神经损伤模型中，单次鞘内注射激活素C可抑制神经性疼痛。
这是首篇研究切断轴突的背根神经节中转化生长因子-β超家族成员转录谱的报告。此处观察到的独特细胞因子谱可能为进一步研究转化生长因子-β超家族在神经性疼痛发病机制及周围神经损伤后轴突退变/再生中的作用提供线索。
