藻蓝蛋白对环磷酰胺诱导的小鼠间质性膀胱炎作用的研究

Effects of phycocyanin on the cyclophosphamide-induced IC/BPS in murine models

目的验证藻蓝蛋白对环磷酰胺诱导的小鼠间质性膀胱炎/膀胱疼痛综合征(IC/BPS)的改善作用及可能机制。方法将30只7~8周雌性小鼠分为3组,IC/BPS疾病模型组接受150mg/kg的环磷酰胺腹腔注射,对照组注射等量生理盐水。藻蓝蛋白组首先预处理藻蓝蛋白(50mg/kg),后环磷酰胺(150mg/kg)注射。3组24h后行排尿测试,结束后获取膀胱和L6节段背根神经节(DRG)。行膀胱组织的HE、甲苯胺蓝染色观察大体形态和计数肥大细胞。Westernblot检测PTGS2和EP4蛋白表达情况。对DRG行免疫荧光分析PTGS2和EP4阳性细胞。结果藻蓝蛋白显著减少了小鼠IC/BPS的排尿次数(从25.80±3.693到13.60±1.708,P<0.05);同时改善了膀胱炎症状态,水肿减轻,膀胱/体重比值(mg/g)也明显下降(由2.082±0.1902降至1.588±0.08810,P<0.05)。Westernblot结果提示藻蓝蛋白降低了膀胱PTGS2和EP4蛋白表达。对DRG的荧光分析提示感觉神经元的EP4蛋白表达增多可能参与介导了膀胱过度活动症状。结论藻蓝蛋白可以通过抑制膀胱PTGS2和EP4蛋白改善环磷酰胺诱导的小鼠间质性膀胱炎症状。

Objective To investigate the role of phycocyanin (PC) in cyclophosphamide (CYP)-induced interstitial cystitis/bladder painful syndrome (IC/BPS) in mice. Methods A total of 30 female mice were randomly divided into 3 groups,with 10 mice in each group.Mice in the CYP group received intraperitoneal injection of 150 mg/kg CYP,while mice in the control group received the same dose of saline.Mice in PC group were pretreated with 50 mg/kg PC,and then injected with 150 mg/kg CYP.Void spot assay (VSA) was performed to record the urinary micturition after 24 hours.The bladders and L6 dorsal root ganglions (DRGs) were harvested.The bladder tissues received HE staining and toluidine blue staining for histological analysis and mastocytes count.The expressions of PTGS2 and EP4 were detected with Western blot.The DRGs were analyzed with immunofluorescence assay to observe the PTGS2 and EP4 positive cells. Results PC reduced micturition frequency from 25.80±3.693 to 13.60±1.708 ( P <0.05),improved cystitis symptoms and relieved edema.The bladder/body weight ratio (mg/g) decreased from 2.082±0.190 2 to 1.588±0.088 10 ( P <0.05).Western blot indicated PC reduced the expressions of PTGS2 and EP4.EP4 expression increased in L6 DRG,indicating that it might be involved in overreactive bladder. Conclusion Phycocyanin alleviated the CYP-induced cystitis in mice by inhibiting the expressions of PTGS2 and EP4 in bladder.