Zong Shoukai, Liang Ziqian, Ou Bangjun
Department of Burns and Plastic, the First Affiliated Hospital of Guangxi Medical University, Nanning Guangxi, 530021, P.R. China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2010 Feb;24(2):150-5.
To investigate the effect of topical external administration of recombinant human epidermal growth factor (rhEGF) when controlling blood sugar on expression of epidermal growth factor receptor (EGFR) and EGFR mRNA of wound in diabetes mellitus (DM) combined with scald.
A total of 136 male Wistar rats weighing (188.57 +/- 6.59) g were randomly divided into 4 groups (groups A, B, C, and D, n=34). The rats was made DM model by intraperitoneal injected 60 mg/kg streptozocin in groups A, B, and C; rats were injected buffer alone in group D as control group. After 8 weeks, the rats of 4 groups were placed in 80 degrees C hot water for 6 seconds for preparation of the back deep II degree scald model. In group A, the blood sugar level was controlled at the level of group D 1 week before scald model; within 24 hours after models preparation, rhEGF was sprayed on wound at 150 U/cm2. In group B, the rats were given the same treatment as group A except not controlling blood sugar. In group C, the blood sugar was controlled as group A and wound was suture fixation with 1% silver sulfadiazine cream at 24 hours after the model. In group D, the same treatment as group A was given after injury. The healing rate of the wound was detected at 3, 7, 11, 15, and 21 days after injury; the EGFR mRNA expression was determined by mRNA hybridization in situ, and the EGFR protein expression was determined by immunohistochemistry and Western blot at 1, 3, 5, 7, 11, 15, and 21 days.
All the rats survived at the end of experiment. There was no significant difference in the healing rate of the wound among the 4 groups at 3 days (P > 0.05). The healing rate of the wound was significantly higher in groups A and D than in groups B and C (P < 0.05) at 7, 11, 15, and 21 days. The expression of EGFR mRNA in 4 groups was observed by hybridization in situ, which mainly distributed in the dermal fibroblasts, capillary endothelial cells and remnants of skin and wound edge epithelium of the subsidiary; the expressions reached the peak at 5 days in group A, at 7 days in groups B and C, and at 11 days in group D; and the peak level was significantly higher in groups A and D than in groups B and C (P < 0.05). Immunohistochemistry and Western blot showed that the expression of EGFR protein was observed in 4 groups and reached the peak level at 7 days in groups A and B, and at 11 days in groups C and D; showing significant difference between groups B, C and groups A, D (P < 0.05).
External application of rhEGF when controlling blood sugar can accelerate obviously the wound healing in DM combined with scald. After controlling blood sugar, external application of rhEGF can boost obviously the expressions of EGFR mRNA, EGFR, and the extending process of signal conduction.
探讨糖尿病（DM）合并烫伤时，外用重组人表皮生长因子（rhEGF）在控制血糖情况下对创面表皮生长因子受体（EGFR）及EGFR mRNA表达的影响。
选取136只体重为（188.57±6.59）g的雄性Wistar大鼠，随机分为4组（A、B、C、D组，n = 34）。A、B、C组大鼠腹腔注射60 mg/kg链脲佐菌素制备DM模型；D组大鼠注射等量缓冲液作为对照组。8周后，将4组大鼠置于80℃热水中6秒制备背部深Ⅱ度烫伤模型。A组在烫伤模型制备前1周将血糖水平控制在D组水平；模型制备后24小时内，以150 U/cm²的剂量将rhEGF喷于创面上。B组给予与A组相同的处理，但不控制血糖。C组血糖控制同A组，模型制备后24小时用1%磺胺嘧啶银乳膏对创面进行缝合固定。D组伤后给予与A组相同的处理。分别于伤后3、7、11、15及21天检测创面愈合率；采用原位mRNA杂交法检测EGFR mRNA表达，采用免疫组织化学法及蛋白质免疫印迹法分别于伤后1、3、5、7、11、15及21天检测EGFR蛋白表达。
实验结束时所有大鼠均存活。伤后3天，4组创面愈合率差异无统计学意义（P＞0.05）。伤后7、11、15及21天，A组和D组创面愈合率明显高于B组和C组（P＜0.05）。原位杂交观察4组EGFR mRNA表达，主要分布于真皮成纤维细胞、毛细血管内皮细胞及创缘附属皮肤和伤口边缘上皮残余；A组于伤后5天表达达高峰，B组和C组于伤后7天达高峰，D组于伤后第11天达高峰；A组和D组的高峰水平明显高于B组和C组（P＜0.05）。免疫组织化学及蛋白质免疫印迹法显示，4组均有EGFR蛋白表达，A组和B组于伤后7天达高峰水平，C组和D组于伤后11天达高峰水平；B、C组与A、D组比较差异有统计学意义（P＜0.05）。
控制血糖时外用rhEGF可明显促进DM合并烫伤创面的愈合。控制血糖后外用rhEGF可显著促进EGFR mRNA、EGFR的表达及信号传导的延长过程。
