糖尿病大鼠创面愈合中巨噬细胞的浸润变化

Macrophage infiltration in the wound healing of diabetic rats

目的对糖尿病创面中巨噬细胞浸润变化的了解有助于探索糖尿病慢性创面愈合困难的原因。文中通过观察糖尿病大鼠全层皮肤缺损创面愈合过程中巨噬细胞浸润的数量及炎症因子的表达,初步探讨其与糖尿病鼠创面愈合延迟的相关性。方法以雄性SD大鼠为实验动物,采用链脲佐菌素诱导形成糖尿病模型鼠设为模型组,对照组为健康同龄SD大鼠,每组15只。在大鼠背部形成面积为1 cm2为全层皮肤缺损,分别于术后第3、7、14天切取创面及创周组织,观察并比较创面的愈合率、巨噬细胞浸润密度及创面组织中IL-12B、诱导型一氧化氮合酶(inducuble nitric oxide synthase,i NOS)、TNF-αmRNA表达量,倒置荧光显微镜观察高倍视野下CCRT阳性细胞染色情况。结果术后第3、7、14天时模型组创面愈合率均低于对照组[(29.5±5.4)%vs(45.9±12.8)%、(71.6±3.1)%vs(80.1±6.9)%、(93.9±2.8)%vs(99.4±1.4)%],差异有统计学意义(P<0.05);HE染色显示第3天时模型组创面组织内的炎症细胞浸润密度低于对照组,而第14天时高于对照组;CD68免疫组化染色显示第3天时模型组大鼠创面组织内巨噬细胞的浸润密度低于对照组(P<0.01),而第14天时则明显高于对照组(P<0.01);针对2组小鼠相关性分析显示,第3天时创面巨噬细胞数和创面愈合率呈正相关(r=0.909,P<0.01),第14天时两者间呈负相关(r=-0.962,P<0.01);模型组创面组织中的炎症因子IL-12B、i NOS、TNF-α的mRNA表达量术后第3天时较对照组降低(P<0.05),而第14天时较对照组升高(P<0.05);创面组织CCR7荧光染色显示第14天时仍有较多阳染细胞残留于模型组创面组织内。结论糖尿病大鼠创面愈合过程中巨噬细胞早期进入创面的数量减少,而晚期则持续停留于创面,同时伴随着相关炎症因子表达量的改变,这可能与糖尿病创面愈合困难具有一定的相关性。

Objective Knowledge about the infiltration of macrophages in diabetic wounds can help to figure out the pathogene -sis of poor healing of diabetic wounds .The aim of this study was to observe the macrophage infiltration and the expression of relative in-flammatory factors during the wound healing of diabetic rats and explore the relationship between macrophages and diabetic wound heal -ing. Methods Male Sprague Dawley rats were randomly divided into STZ induced diabetic group and normal control group .Each group had 15 rats.A 1 cm2 full-thickness skin defect was created on the rat dorsum .Wound samples and was excised .On post injury day （PID） 3, 7, and 14, rats of each group were sacrificed after wound samples and tissues around the wound edge were obtained .The differences of the wound closure rate , macrophage infiltration and the relative mRNA expression of the inflammatory factors from macro-phages were observed . Results The wound closure rate was lower in diabetic group on PID 3, 7, and 14 （[29.5 ±5.4]%vs [45.9 ± 12.8]%, [71.6 ±3.1]%vs [80.1 ±6.9]%, [93.9 ±2.8]%vs [99.4 ±1.4]%, P〈0.05）.HE staining showed inflammatory cells infil-diabetic wound tissue on PID 3 （P〈0.05） and a higher expression on PID 14 （P〈0.05）.The CCR7 fluorescence staining showed more positive staining cells stayed in diabetic wound on PID 14. Conclusion Macrophage infiltration decreases in the early phase of diabetic wound healing and sustains in wound tissue in advanced stage accompanied by the expression change of related inflammatory factors, which could contribute to the difficult wound healing of diabetic rats .