A Neuropeptide Y/F-like Polypeptide Derived from the Transcriptome of Turbinaria peltata Suppresses LPS-Induced Astrocytic Inflammation

Neuropeptides are a group of neuronal signaling molecules that regulate physiological and behavioral processes in animals. Here, we used in silico mining to predict the polypeptide composition of available transcriptomic data of Turbinaria peltata. In total, 118 transcripts encoding putative peptide precursors were discovered. One neuropeptide Y/F-like peptide, named TpNPY, was identified and selected for in silico structural, in silico binding, and pharmacological studies. In our study, the anti-inflammation effect of TpNPY was evaluated using an LPS-stimulated C8-D1A astrocyte cell model. Our results demonstrated that TpNPY, at 0.75–3 μM, inhibited LPS-induced NO production and reduced the expression of iNOS in a dose-dependent manner. Furthermore, TpNPY reduced the secretion of proinflammatory cytokines. Additionally, treatment with TpNPY reduced LPS-mediated elevation of ROS production and the intracellular calcium concentration. Further investigation revealed that TpNPY downregulated the IKK/IκB/NF-κB signaling pathway and inhibited expression of the NLRP3 inflammasome. Through molecular docking and using an NPY receptor antagonist, TpNPY was shown to have the ability to interact with the NPY Y1 receptor. On the basis of these findings, we concluded that TpNPY might prevent LPS-induced injury in astrocytes through activation of the NPY-Y1R.

神经肽（Neuropeptides）是一类调控动物生理与行为过程的神经元信号分子。本研究通过计算机模拟（in silico）挖掘技术，对已公开的铜藻（Turbinaria peltata）转录组数据进行多肽组分预测，共发掘出118条编码假定肽前体的转录本。从中筛选得到1种神经肽Y/F样肽，命名为TpNPY，并对其开展计算机模拟结构分析、结合实验与药理学研究。本研究采用脂多糖（LPS）诱导的C8-D1A星形胶质细胞模型，评估TpNPY的抗炎活性。结果显示，在0.75~3 μM浓度范围内，TpNPY以剂量依赖性方式抑制脂多糖诱导的一氧化氮（NO）生成，并降低诱导型一氧化氮合酶（iNOS）的表达水平。此外，TpNPY可减少促炎细胞因子的分泌；同时，TpNPY处理能够缓解脂多糖介导的活性氧（ROS）生成增多与细胞内钙离子浓度升高。进一步机制研究表明，TpNPY可下调IKK/IκB/NF-κB信号通路活性，并抑制NLRP3炎症小体的表达。通过分子对接实验与神经肽Y受体拮抗剂干预实验，本研究证实TpNPY可与神经肽Y Y1受体（NPY Y1R）相互结合。基于上述实验结果，本研究认为TpNPY可能通过激活神经肽Y Y1受体，减轻脂多糖诱导的星形胶质细胞损伤。