目的 从丝裂原活化蛋白激酶(MAPK)/胞外信号调节激酶1/2(ERK1/2)/c-Jun氨基末端激酶1/2(JNK1/2)通路探究染料木黄酮对荨麻疹大鼠的保护机制。方法SD大鼠随机分为对照组、模型组、染料木黄酮低、高剂量(150、300 mg/kg)组,MAPK激活剂(茴香霉素)组、染料木黄酮+茴香霉素组,每组12只。通过卵蛋白血清致敏诱导建立大鼠慢性荨麻疹模型。观察大鼠搔抓症状;ELISA法检测血清免疫球蛋白E抗体(IgE)及炎症介质如组胺、白三烯、前列腺素(PGD2)、5-羟色胺(5-HT)水平;伊文思蓝染色观察血管通透性改变;苏木精-伊红(HE)染色观察蓝斑皮肤组织病理变化;取腹腔肥大细胞计算脱颗粒比率;免疫组化法观察蓝斑组织皮肤中磷酸化MAPK(p-MAPK)阳性表达水平;Western blotting法检测蓝斑组织皮肤中MAPK-ERK1/2-JNK1/2通路蛋白表达及上游酪氨酸激酶(Lyn)、脾酪氨酸激酶(Syk)磷酸化蛋白、下游激活蛋白-1(AP-1)、炎症通路核转录因子κB(NF-κB)蛋白表达。结果 与对照组相比,模型组大鼠搔抓次数增多、耳部血管通透性升高、血清IgE及炎症介质分泌增多、肥大细胞脱颗粒比率升高、大鼠背部皮肤水肿及炎性浸润等病理损伤均加重,背部蓝斑组织MAPK/ERK/JNK通路活化,其下游炎症及脱颗粒相关通路蛋白表达升高(P<0.05)。与模型组相比,染料木黄酮低、高剂量组大鼠搔抓次数减少,耳部血管通透性和肥大细胞脱颗粒比率降低,血清IgE及炎症反应降低,背部皮肤水肿及炎性浸润等病理损伤减轻,MAPK/ERK/JNK通路及其介导的炎症、脱颗粒等信号途径活化受到抑制(P<0.05),且染料木黄酮300 mg/kg组上述抑制作用更明显(P<0.05)。茴香霉素可逆转染料木黄酮的上述作用(P<0.05)。结论 染料木黄酮可抑制MAPK-ERK1/2-JNK1/2通路活化,阻断肥大细胞脱颗粒,改善荨麻疹病理症状。

Objective From the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1/2 (ERK1/2)/c-Jun N-terminal kinase 1/2 (JNK1/2) pathway, to explore the protective mechanism of genistein on urticaria rats. Methods SD rats were randomly divided into control group, model group, genistein low and high dose groups, MAPK activator (anisomycin) group, and genistein + anisomycin group, with 12 rats in each group. The rat model of chronic urticaria was established by serum sensitization induced by albumin. The scratching symptoms of rats were observed, ELISA method was used to detect the levels of serum immunoglobulin E antibody (IgE) and inflammatory mediators such as histamine, leukotriene, PGD2, 5-HT, etc. Evans blue staining was used to observe changes in vascular permeability. HE staining was used to observe the pathological changes of locus coeruleus skin tissue, the mast cells of the abdominal cavity was taken to calculate the degranulation ratio, immunohistochemical method was used to observe the positive expression level of phosphorylated MAPK (p-MAPK) in the skin of locus coeruleus tissue. Western Blotting method was used to detect the expression of MAPK-ERK1/2-JNK1/2 pathway protein in the skin of locus coeruleus tissue, and the expression of upstream tyrosine kinase (Lyn), spleen tyrosine kinase (Syk) phosphorylation protein, downstream activator protein-1 (AP-1) and inflammatory pathway nuclear transcription factor-κB (NF-κB) protein. Results Compared with the control group, rats in the model group had increased the number of scratches, increased ear vascular permeability, increased the secretion of serum IgE and inflammatory mediators, and mast cell degranulation rate. The pathological damage of dorsal skin edema and inflammatory infiltration was aggravated. The MAPK/ERK/JNK pathway was activated in dorsal locus coeruleus, and the protein expression of downstream inflammation and degranulation related pathway was increased (P < 0.05). Compared with model group, genistein group reduced scratching times, ear vascular permeability, and mast cell degranulation rate. And the vascular permeability and mast cell degranulation ratio were decreased, serum IgE and inflammatory response were decreased, pathological damage of back skin edema and inflammatory infiltration were alleviated, and activation of MAPK/ERK/JNK pathway and its mediated inflammation and degranulation signal pathway were inhibited (P < 0.05). The higher the dose of genistein was, the more obvious the inhibition was (P < 0.05). Anisomycin could reverse the above effects of genistein (P < 0.05). Conclusion Genistein can inhibit the activation of the MAPK-ERK1/2-JNK1/2 pathway, block the degranulation of mast cells, and improve the pathological symptoms of urticaria.

R965

河南省医学科技攻关计划联合共建项目（LHGJ20200904）