Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, 130024, PR China.
Jilin Province Key Laboratory on Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun, 130024, PR China.
Carbohydr Polym. 2018 Mar 1;183:207-218. doi: 10.1016/j.carbpol.2017.12.017. Epub 2017 Dec 11.
We isolated and purified a new polysaccharide (WFVP-N-b1) with a molecular weight of 20 kDa from Flammulina velutipes. Results showed that WFVP-N-b1 is composed of an α (1 → 6)-linked D-galactan backbone and branched at the O-2 of its Galp residues by an α-D-(1 → 6)-linked Manp attached to t-β-D-Glcp or t-α-D-Fucp side chains. WFVP-N-b1 can significantly induce cytokines secretion and release of toxic molecules. On a cellular level, WFVP-N-b1 is recognized by Toll-like receptor 4 (TLR4). Thereby, the hetero-galactan increased the phosphorylation of mitogen-activated protein kinases (MAPKs) and Akt, promoted degradation of IκB-α and the nuclear translocation of the NF-κB p65 subunit. Importantly, our results indicate that WFVP-N-b1 activated macrophage is mediated by autophagy, as blockade of WFVP-N-b1-induced autophagy by Baf-A1 significantly decreases macrophage activation. This is the first report that hetero-galactan-induced macrophage activation is mediated by autophagy. Collectively, WFVP-N-b1 activated RAW264.7 cells through MAPKs, autophagy, and Akt/NF-κB signaling pathways via TLR4 receptor.
我们从金针菇中分离和纯化出一种分子量为 20kDa 的新多糖（WFVP-N-b1）。结果表明，WFVP-N-b1 由α（1→6）-连接的 D-半乳糖聚糖主链组成，其 Galp 残基的 O-2 通过连接到 t-β-D-Glcp 或 t-α-D-Fucp 侧链的α-D-（1→6）-连接的 Manp 分支。WFVP-N-b1 可以显著诱导细胞因子的分泌和有毒分子的释放。在细胞水平上，WFVP-N-b1 被 Toll 样受体 4（TLR4）识别。因此，杂半乳糖增加了丝裂原活化蛋白激酶（MAPKs）和 Akt 的磷酸化，促进了 IκB-α 的降解和 NF-κB p65 亚基的核转位。重要的是，我们的结果表明，WFVP-N-b1 激活巨噬细胞是通过自噬介导的，因为 Baf-A1 阻断 WFVP-N-b1 诱导的自噬会显著降低巨噬细胞的激活。这是首次报道杂半乳糖诱导的巨噬细胞激活是通过自噬介导的。总之，WFVP-N-b1 通过 TLR4 受体通过 MAPKs、自噬和 Akt/NF-κB 信号通路激活 RAW264.7 细胞。
