咪喹莫特调节Th1、Th2细胞相关趋化因子表达抑制兔耳瘢痕增生

目的:免疫因素在增生性瘢痕的发生中起重要作用,本实验研究免疫抑制剂咪喹莫特对兔耳增生性瘢痕组织中辅助性T淋巴(Th)细胞亚群Th1、Th2细胞相关趋化因子CXCL10、CXCL12、CCL2、CCL3、CCL5、CCL7、CCL13表达的影响,探讨咪喹莫特抑制兔耳瘢痕增生的作用机制。方法:选取16只新西兰大耳白兔,雌雄不限。建立兔耳增生性瘢痕模型,每只兔耳腹侧做四个直径为1 cm的圆形创面,每个相距1.5 cm,双侧对称,右耳为咪喹莫特组涂抹5%咪喹莫特软膏,左耳为空白对照组涂抹等量凡士林软膏,待术后14天上皮化均完全后开始涂抹,一日一次,持续一个月。分别于术后第21、28、35、42、49、56、63天同一时间空气栓塞法随机处死2只兔子,收集所有瘢痕标本。另外处死2只健康兔并采集兔耳正常皮肤组织。所有标本行HE染色及Masson三色法染色,观察形态学差异;测量并计算瘢痕增生指数(Scar elevation index,SEI);行Real-time PCR检测CXCL10、CXCL12、CCL2、CCL3、CCL5、CCL7、CCL13的表达。结果:HE及Masson染色可见咪喹莫特组胶原沉积较空白对照组明显减少,SEI显示空白对照组于术后第28天增生程度达到高峰,其增生程度明显高于咪喹莫特组(P0.05);Real-time PCR结果可见咪喹莫特组Th2细胞相关趋化因子CCL2、CCL3、CCL5、CCL7及CCL13表达在各时间点较空白对照组明显降低,Th1细胞相关趋化因子CXCL10、CXCL12的表达在各时间点较空白对照组明显增高(P0.05)。结论:咪喹莫特可通过调节Th1、Th2细胞相关趋化因子的表达来发挥抑制兔耳瘢痕增生的作用。

Imiquimod Inhibit Scar Formation by Regulating the Expression of Th1/Th2 Cell Related Chemokines in Rabbit Ear Hypertrophic Scar Model

Objective:Immunological factors play an important role in the formation of hypertrophic scars. Our researchis aimed to investigate the influence on the expression of Th1/Th2 cell related chemokines CXCL10, CXCL12, CCL2, CCL3, CCL5, CCL7 and CCL13 in rabbit ear hypertrophic scar by imiquimod which is a kind of immunosuppressors and to discuss the inhibitory effect and mechanism of imiquimod on rabbit ear hypertrophic scar formation.Methods:Sixteen New Zealand White rabbits were employed in this study. Rabbit ear hypertrophic scar model was builded on the basis of the previous literature of our laboratory. Four round wounds were cut in each rabbit ears ventral that diameter of 1cm, bilateral symmetry. All the right ear wounds were treated with 5%imiquimod cream. The blank control group contains all the left ear wounds and were treated with vaseline ointment at the same time. Every wounds were applied cream after healing, once a day, for a month. Normal rabbir ear skins were harvested on 0 day and both of the groups were harvested at the same time on the 21st, 28th, 35th, 42nd, 49th, 56th, 63rd day after operation. Two rabbits were killed by air embolism every time. Hematoxylin-eosin staining and Masson trichrome staining were performed after fixing to observe morphological differences. The expression of CXCL10,CXCL12,CCL2,CCL3,CCL5,CCL7 and CCL13 was detected by Real-time PCR.Results:The sections of HE and Masson show that compared with that in the blank control group, the level of the collagen deposition reduced significantly in the imiquimod group. The SEI of the blank control group shows the degree of proliferation peaked at 28 days and it was significantly higher than the imiquimod group(P<0.05). The mRNA level of Th2 cell related chemokines CCL2,CCL3,CCL5,CCL7,CCL13 were significantly lower in imiquimod group than blank control group and the mRNA level of Th1 cell related chemokines CXCL10,CXCL12 were significantly higher in imiquimod group than blank control group at every time point(P<0.05).Conclusion:Imiquimod probablely inhibits scar formation by regulating the expression of Th1/Th2 cell related chemokines in rabbit ear hypertrophic scar model.