神经炎症涉及小胶质细胞表型的不同改变,含有恶性促炎M1表型和神经保护性抗炎M表型。目前,没有有效的治疗方法来调节这种改变。通过qPCR检测受褪黑素影响的原代小胶质细胞的M1/M2标记。通过西方印迹探索功能活动,荧光素酶活性,EMSA,和ChIP分析。通过分子对接和LIGPLOT分析评估结构相互作用。通过超微结构TEM检查ER应力检测,calapin活动,和ERSE测定。功能性神经行为评估用于研究褪黑素对体内神经炎症的影响。褪黑素靶向过氧化物酶体增殖物激活受体δ(PPARδ)活性,增强LPS刺激的从M1到M2表型的极化改变,从而抑制原发性小胶质细胞中NFκB-IKKβ的活化。PPARδ激动剂L-165,041或过表达的PPARδ质粒(ov-PPARδ)显示相似的结果。分子对接筛选,动态仿真方法,褪黑素的生物学研究表明,激活位点位于PPARδ(磷酸-Thr256-PPARδ)。活化的小胶质细胞通过增强ER应激降低了PPARδ活性以及下游SIRT1的形成。褪黑激素,PPARδ激动剂和ov-PPARδ均有效逆转了上述作用。褪黑素通过调节LPS激活的小胶质细胞中的calapin活性和表达来阻断ER应激。此外,褪黑素或L-165,041通过阻断小胶质细胞活动改善了LPS加重的神经炎小鼠的神经行为缺陷,并促进M2型小胶质细胞的表型改变。褪黑素通过ER-应激依赖性PPARδ/SIRT1信号级联调节小胶质细胞活化,在体外和体内抑制神经炎症。该治疗策略是用于治疗神经炎症相关病症的令人鼓舞的药理学方法。
Neuro-inflammation involves distinct alterations of microglial phenotypes, containing nocuous pro-inflammatory M1-phenotype and neuroprotective anti-inflammatory M-phenotype. Currently, there is no effective treatment for modulating such alterations. M1/M2 marker of primary microglia influenced by Melatonin were detected via qPCR. Functional activities were explored by western blotting, luciferase activity, EMSA, and ChIP assay. Structure interaction was assessed by molecular docking and LIGPLOT analysis. ER-stress detection was examined by ultrastructure TEM, calapin activity, and ERSE assay. The functional neurobehavioral evaluations were used for investigation of Melatonin on the neuroinflammation in vivo. Melatonin had targeted on Peroxisome Proliferator Activated Receptor Delta (
PPARδ) activity, boosted LPS-stimulated alterations in polarization from the M1 to the M2 phenotype, and thereby inhibited NFκB-IKKβ activation in primary microglia. The
PPARδ agonist L-165,041 or over-expression of
PPARδ plasmid (ov-
PPARδ) showed similar results. Molecular docking screening, dynamic simulation approaches, and biological studies of Melatonin showed that the activated site was located at PPARδ (phospho-Thr256-
PPARδ). Activated microglia had lowered
PPARδ activity as well as the downstream SIRT1 formation via enhancing ER-stress. Melatonin,
PPARδ agonist and ov-
PPARδ all effectively reversed the above-mentioned effects. Melatonin blocked ER-stress by regulating calapin activity and expression in LPS-activated microglia. Additionally, Melatonin or L-165,041 ameliorated the neurobehavioral deficits in LPS-aggravated neuroinflammatory mice through blocking microglia activities, and also promoted phenotype changes to M2-predominant microglia. Melatonin suppressed neuro-inflammation in vitro and in vivo by tuning microglial activation through the ER-stress-dependent PPARδ/SIRT1 signaling cascade. This treatment strategy is an encouraging pharmacological approach for the remedy of neuro-inflammation associated disorders.