College of Life Science, Henan Normal University, Xinxiang 453007, PR China.
Food Funct. 2017 Dec 13;8(12):4675-4683. doi: 10.1039/c7fo01064h.
(-)-Epigallocatechin-3-gallate (EGCG) exhibits a broader spectrum health efficacy in subarachnoid hemorrhage (SAH) therapy; the mechanisms, however, are largely unknown. Given that miRNAs play important roles in regulation of thousands of gene expressions, the effect of EGCG on the expression of miRNAs was investigated to explore the multi-targeting actions of EGCG by using an in vitro SAH model. MTT and western blot assays were used to assess the health effects of EGCG in SAH progression; the results showed that oxyhemoglobin (OxyHb)-induced cell proliferation and excessive autophagic activation were significantly inhibited by 50 μM EGCG, but not by 1 μM EGCG. By high throughput sequencing analysis, the miRNA profiles of normal, SAH and EGCG (1 and 50 μM) groups were compared and a total of 953 miRNAs were identified. Of 192 differentially expressed miRNAs, 43 miRNAs were significantly differentially expressed in SAH (p < 0.01). However, EGCG significantly increased the number of differential expressions of miRNAs, which showed 144 and 138 miRNAs (112 and 115 upregulated, 32 and 23 downregulated, p < 0.01) in 1 μM and 50 μM EGCG groups, respectively. Among all the differentially expressed miRNAs, 13 miRNAs were shared by the three groups. 5 miRNAs (miR-218-5p, miR-218b, miR-143-3p, miR-101a-3p, miR-30a-3p) were detected in both SAH and EGCG 1 μM groups, and 104 miRNAs were shared by the EGCG 1 μM and EGCG 50 μM groups. Only 1 miRNA (miR-532-5p) was discovered in both SAH and EGCG 50 μM groups. Moreover, 24, 22 and 20 specific differentially expressed miRNAs were discovered in SAH, 1 μM and 50 μM EGCG groups, respectively. The predicted target genes of differentially expressed miRNAs showed that the most impacted MAPK signaling pathway, particularly the upregulated p38 expression in the SAH group, was restored to the normal level in both EGCG groups, but the calcium signaling pathway was enriched only in the EGCG 50 μM group. These results revealed that differential expression of miRNAs is fundamental to understand the multiple targets actions of EGCG in SAH therapy, and simultaneously targeting more robust signaling pathways could determine the therapeutic effects of EGCG.
(-)-表没食子儿茶素-3-没食子酸酯 (EGCG) 在蛛网膜下腔出血 (SAH) 治疗中表现出更广泛的谱健康功效；然而，其机制在很大程度上尚不清楚。鉴于 miRNA 在调节数千个基因表达中发挥重要作用，本研究通过体外 SAH 模型研究了 EGCG 对 miRNA 表达的影响，以探索 EGCG 的多靶向作用。MTT 和 Western blot 测定用于评估 EGCG 在 SAH 进展中的健康影响；结果表明，50μM EGCG 显著抑制氧合血红蛋白 (OxyHb) 诱导的细胞增殖和过度自噬激活，但 1μM EGCG 则没有。通过高通量测序分析，比较了正常、SAH 和 EGCG(1 和 50μM)组的 miRNA 图谱，共鉴定出 953 个 miRNA。在 192 个差异表达的 miRNA 中，43 个 miRNA 在 SAH 中差异显著表达(p<0.01)。然而，EGCG 显著增加了 miRNA 差异表达的数量，1μM 和 50μM EGCG 组分别显示 144 和 138 个 miRNA(112 个上调，115 个上调，32 个下调，23 个下调，p<0.01)。在所有差异表达的 miRNA 中，有 13 个 miRNA 在三组中均有表达。在 SAH 和 EGCG 1μM 组中均检测到 5 个 miRNA(miR-218-5p、miR-218b、miR-143-3p、miR-101a-3p、miR-30a-3p)，而在 EGCG 1μM 和 EGCG 50μM 组中则有 104 个 miRNA 共享。只有 1 个 miRNA(miR-532-5p)在 SAH 和 EGCG 50μM 组中均有发现。此外，在 SAH、1μM 和 50μM EGCG 组中分别发现了 24、22 和 20 个特异性差异表达的 miRNA。差异表达 miRNA 的预测靶基因显示，受影响最大的 MAPK 信号通路，特别是 SAH 组中 p38 的上调，在两个 EGCG 组中均恢复到正常水平，但钙信号通路仅在 EGCG 50μM 组中富集。这些结果表明，miRNA 的差异表达是理解 EGCG 在 SAH 治疗中的多靶向作用的基础，同时靶向更强大的信号通路可以确定 EGCG 的治疗效果。
