Sphingosine-1-phosphate signal transducer and activator of transcription 3 signaling pathway contributes to baicalein-mediated inhibition of dextran sulfate sodium-induced experimental colitis in mice
Sphingosine-1-phosphate signal transducer and activator of transcription 3 signaling pathway contributes to baicalein-mediated inhibition of dextran sulfate sodium-induced experimental colitis in mice
复制标题
1-磷酸鞘氨醇信号转导器和转录激活剂 3 信号通路有助于黄芩素介导的对葡聚糖硫酸钠诱导的小鼠实验性结肠炎的抑制
DOI：
10.1097/cm9.0000000000000627
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发表时间：
2020-02-05
影响因子：
6.1
通讯作者：
Wang, Chuan-Gong
中科院分区：
文献类型：
--
作者：
Yao, Jing;Liu, Tao;Wang, Chuan-Gong
摘要背景：黄芩素已被证明具有抗炎和抗肿瘤活性。然而，其对结肠炎的抗炎作用机制尚不清楚。方法：6~8周龄，体重18~22 g的BALB/c小鼠，建立葡聚糖硫酸钠诱导的急性结肠炎模型。6组小鼠：(1)饮水10天(对照组)，n = 6；(2)4%DSS水溶液饮水7天，然后用普通水3天，n = 7；(3)，(4)，(5)组2加黄芩素(10，20，40 mg/kg)，从第1天开始，每日1次，n = 6；(6)(2)加用5-氨基水杨酸(50 mg/kg)，从第1天开始每日1次，n = 6。记录体重、大便稠度和便血，并用疾病活动性指数评估结肠炎的严重程度。第11天处死小鼠，采集脏器和血液进行分析。采用酶联免疫吸附试验检测血清炎症因子，免疫荧光显微镜检测CD11b阳性细胞，免疫组织化学方法检测视黄酸受体相关孤儿核受体γ、鞘氨醇激酶1(SPHK1)、磷酸化信号转导和转录激活因子3(p-STAT3)的表达，Western blotting检测核苷酸结合寡聚化结构域2(NOD2)、SPHK1、1-磷酸鞘氨醇受体1(S1PR1)、总STAT3和p-STAT3的表达。组间差异比较采用t检验。结果：黄芩素治疗可剂量依赖地减少DSS所致的体重减轻(P <； 0.0 1或P <； 0.0 5)、脾肿大(P <； 0.0 1)和结肠损伤，表现为腹泻、直肠出血和结肠溃疡、充血、水肿(表现为结肠长度，P <； 0.0 5或P <； 0.0 1)和炎性细胞浸润。黄芩素还能显著降低血清(P <； )和结肠组织中炎症介质的水平，显著抑制结肠组织中NOD2SPHK1、S1PR1和p-STAT3的表达(P <； 0.05)。结论：黄芩素可通过抑制S1P-STAT3信号转导途径改善小鼠结肠炎，提示该类黄酮类化合物可能对结肠炎有一定的治疗作用。
Abstract Background: Baicalein has been shown to have anti-inflammatory and anti-tumor activities. However, the mechanisms underlying its anti-inflammatory effect on colitis remain unclear. Methods: A dextran sodium sulfate (DSS)-induced model of acute colitis was established in BALB/c mice (6–8 weeks old, weighing 18–22 g). Six groups of mice received: (1) water for 10 days (control), n = 6; (2) DSS 4% solution in the drinking water for 7 days, followed by normal water for 3 days, n = 7; (3), (4), and (5) as for group 2 plus baicalein (10, 20, 40 mg/kg) administered once daily starting on day 1, n = 6; and (6) as for (2) plus 5-aminosalicylic acid (50 mg/kg) administered once daily starting on day 1, n = 6. Body weights, stool consistency, and hematochezia were recorded, and the severity of colitis was evaluated using a disease activity index. On day 11, the mice were euthanized, and organs and blood were collected for analysis. Serum inflammatory factors were detected by enzyme-linked immunosorbent assay; CD11b-positive cells were analyzed by immunofluorescence microscopy; expression of retinoic-acid-receptor-related orphan nuclear receptor gamma, sphingosine kinase 1 (SPHK1), and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) was detected by immunohistochemistry; and expression of nucleotide-binding oligomerization domain 2 (NOD2), SPHK1, sphingosine 1-phosphate receptor 1 (S1PR1), total STAT3, and p-STAT3 were detected by western blotting analysis. Inter-group differences were compared using Student's t test. Results: Baicalein treatment dose-dependently reduced DSS-induced weight loss (P < 0.01 or P < 0.05), splenomegaly (P < 0.01), and colonic damage, as reflected by amelioration of diarrhea, rectal bleeding, and colonic ulceration, congestion, edema (shown as colon length, P < 0.05 or P < 0.01), and inflammatory cell infiltration. Baicalein also significantly decreased the levels of inflammatory mediators in the serum (P < 0.01) and colon, and significantly inhibited expression of NOD2 SPHK1, S1PR1, and p-STAT3 in the colon (P < 0.05). Conclusions: Baicalein treatment ameliorated colitis in mice by inhibiting S1P-STAT3 signaling, suggesting that this flavonoid might be beneficial in the treatment of colitis.