单核细胞趋化因子-1在间质性膀胱炎大鼠模型中表达和作用机制的研究

Study on the expression and mechanism of monocyte chemoattractant protein-1 in interstitial cystitis rats

目的探讨单核细胞趋化因子（MCP-1）在间质性膀胱炎（Ic）大鼠模型中的表达和作用机制。方法20只体质量为250～300g的雌性SD大鼠分为Ic组和对照组，每组各10只。IC组采用经尿道灌注浓度为10mg／ml的硫酸鱼精蛋白1ml，保留45min，然后灌注浓度为750μg／ml的脂多糖1ml，保留30min，24h后重复操作1次，3d后处死大鼠留取膀胱组织和尿液。对照组采用PBS溶液同法膀胱灌注，留取大鼠的膀胱组织和尿液。ELISA方法检测Ic大鼠膀胱组织和尿液中MCP-1以及组胺的表达水平变化。HE染色观察膀胱组织炎症情况，肥大细胞（MC）染色观察膀胱组织MC脱颗粒情况并计数分析。免疫组化染色观察大鼠膀胱组织MCP-1的表达分布情况，并以免疫荧光方法分析MCP-1和MC之间的关系。结果Ic组大鼠膀胱组织和尿液中MCP-1和组胺的表达水平[（2115．9±650．3）和（103．2±35．7），（2303．9±567．2）和（52．3±12．1）pg／ml]较对照组[（58．1±12．5）和（19．8±8．5），（205．4±58．1）和（19．8±10．7）pg／ml]显著升高（P〈0．01）。HE染色，IC组膀胱黏膜有较多炎症细胞浸润，黏膜明显水肿增厚，并可见毛细血管充血和出血；IC组和对照组单核炎症细胞计数分别为（76．5±9．8）和（18．5±9．8）个／视野（P〈0．01），脱颗粒MC计数分别为（6．4±3．1）和（0．7±0．3）个／视野（P〈0．01）。免疫组化和免疫荧光检测发现，IC大鼠膀胱黏膜上皮中MCP-1有较高表达，膀胱间质中的MC表面及周围有较多的MCP-1聚集。结论MCP．1在Ic大鼠中有较高表达，并可能与大鼠膀胱组织中的MC结合，诱导激活MC脱颗粒释放组胺，从而加重IC炎性和纤维化的病理过程。

Objective To observe the expression and mechanism of monocyte ehemoattractant pro- tein-1 （ MCP-1 ） in interstitial cystitis （IC） rats. Methods Twenty weight of 250 - 300 g of female SD rats were divided into IC group （n = 10） and control group （n = 10）. IC group were treated by transurethral instillation with 10 mg/ml protamine sulfate （PS） 1 ml reserved for 45 min, and then instillation with 750 ug/ml of lipopolysaccharide （LPS） I ml reserved for 30 rain. The same operations were repeated after 24 hours, and the rats were killed obtaining the bladder tissue and urine after three days. Control group was given PBS solution perfusion. MCP-1 and histamine （HA） expression levels in the rat bladder tissue and urine were detected by ELISA. The inflammation of bladder tissue was observed and inflammatory score was used by tiE staining. MC degranulation count was used by MC special staining. MCP-1 expression and distribu- tion in bladder tissue was observed by immunohistochemical method. The relationship between the MCP-1 and MC was detected by immunofluorescence method. Results By ELISA, the expression levels of MCP- 1 and HA in the bladder tissue and urine in IC group were significantly increased compared with control group （P 〈0.01 ）. More inflammatory cell infiltration in the bladder mucosa, edema mucosa, congestion and hemorrhage were seen by HE staining. The inflammatory score in IC and control group were （76.5 ± 9.8） and （18.5 ± 9. 8 ）/field （P 〈 0.01 ）. With MC special staining, degranulation MC count in IC and control group were （ 6.4 ± 3.1 ） and （0.7 ± 0.3 ）/field （ P 〈 0.01 ） , and the degranulation in the bladder tissue of IC group was significantly higher than control group （P 〈 0.01 ）. MCP-1 has a higher expression in the bladder epithelium, and more MCP-1 were found gathering round MC surface by immunofluorescence. Conclusions MCP-1 is highly expressed in IC rats, and could induced activation of MC, which could release HA, aggravating the pathological process of inflammatory and fibrosis in IC.