Jiang Qian, Wei Ding, He Xuejun, Gan Chao, Long Xiaobing, Zhang Huaqiu
Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Neurosurgery, Tianyou Hospital Affiliated to Wuhan University of Science & Technology, Wuhan, China.
Front Pharmacol. 2021 Oct 20;12:719823. doi: 10.3389/fphar.2021.719823. eCollection 2021.
Phillyrin (Phi) is the main polyphenolic compound found in . Recent studies have revealed that Phi has potent antioxidative and anti-inflammatory effects. However, whether Phi could relieve blood-brain barrier (BBB) damage following traumatic brain injury (TBI) remains unknown. Lipopolysaccharide (LPS) was used to activate primary microglia, which were then treated with different doses of Phi or the peroxisome proliferator-activated receptor-gamma (PPARγ) antagonist (GW9662). CCK-8 assay was used for evaluating cell viability, and the cytokines (including IL-1β, IL-6, TNFα, IL-4, IL-10, and TGFβ), microglial phenotypic markers (iNOS, COX2, and CD86 for "M1" polarization; Arg1, Ym1, and CD206 for "M2" polarization), PPARγ, and NF-κB were determined by RT-PCR, Western blot, or cellular immunofluorescence. Primary cultured mouse brain microvascular endothelial cells (BMECs) were stimulated by the condition medium (CM) from microglia. The cell viability, angiogenesis, and tight junction of BMECs were determined CCK-8 assay, tube formation assay, and Western blot (for detecting MMP3, MMP9, ZO1, claudin-5, and occludin). Furthermore, the mouse TBI model was constructed and treated with Phi and/or GW9662. The BBB integrity was evaluated by H&E staining, Evans blue staining, and tissue immunofluorescence. Phi markedly restrained the pro-inflammatory ("M1" state) cytokines and promoted anti-inflammatory ("M2" polarization) cytokines in LPS-mediated microglia. Phi mitigated "M1" polarization and promoted "M2" polarization of microglia enhancing PPARγ and inhibiting the NF-κB pathway. The PPARγ antagonist GW9662 significantly repressed Phi-mediated anti-inflammatory effects. Meanwhile, Phi enhanced the viability, tube formation ability, and cell junction of BMECs. In the TBI mouse model, Phi promoted "M2" polarization, whereas it repressed the "M1" polarization of microglia. In addition, Phi reduced TBI-mediated BBB damage. However, the protective effects of Phi were reversed mainly by GW9662 treatment. Phi prevents BBB damage inhibiting the neuroinflammation of microglia through the PPARγ/NF-κB pathway, which provides a potential therapeutic drug against TBI.
连翘苷（Phi）是[具体来源未提及]中发现的主要多酚类化合物。最近的研究表明，Phi具有强大的抗氧化和抗炎作用。然而，Phi是否能减轻创伤性脑损伤（TBI）后的血脑屏障（BBB）损伤仍不清楚。使用脂多糖（LPS）激活原代小胶质细胞，然后用不同剂量的Phi或过氧化物酶体增殖物激活受体γ（PPARγ）拮抗剂（GW9662）处理。采用CCK-8法评估细胞活力，并通过RT-PCR、蛋白质免疫印迹或细胞免疫荧光法检测细胞因子（包括IL-1β、IL-6、TNFα、IL-4、IL-10和TGFβ）、小胶质细胞表型标志物（“M1”极化的iNOS、COX2和CD86；“M2”极化的Arg1、Ym1和CD206）、PPARγ和NF-κB。原代培养的小鼠脑微血管内皮细胞（BMECs）用小胶质细胞的条件培养基（CM）刺激。通过CCK-8法、管形成试验和蛋白质免疫印迹（用于检测MMP3、MMP9、ZO1、claudin-5和occludin）测定BMECs的细胞活力、血管生成和紧密连接。此外，构建小鼠TBI模型并用Phi和/或GW9662处理。通过苏木精-伊红染色、伊文思蓝染色和组织免疫荧光评估BBB完整性。Phi显著抑制LPS介导的小胶质细胞中促炎（“M1”状态）细胞因子，并促进抗炎（“M2”极化）细胞因子。Phi通过增强PPARγ和抑制NF-κB途径减轻小胶质细胞的“M1”极化并促进“M2”极化。PPARγ拮抗剂GW9662显著抑制Phi介导的抗炎作用。同时，Phi增强了BMECs的活力、管形成能力和细胞连接。在TBI小鼠模型中，Phi促进“M2”极化，而抑制小胶质细胞的“M1”极化。此外，Phi减少了TBI介导的BBB损伤。然而，Phi的保护作用主要通过GW9662处理而逆转。Phi通过PPARγ/NF-κB途径抑制小胶质细胞的神经炎症，从而预防BBB损伤，这为TBI提供了一种潜在的治疗药物。
