脂肪血管基质组分在急性放射性皮肤损伤微环境中转归的动物模型构建

Development of an animal model for studying the conversion of stromal vascular fraction in the microenvironment of acute cutaneous radiation injury

目的:探讨一种脂肪血管基质组分(SVF)治疗急性放射性皮肤损伤的动物模型以研究SVF的转归。方法:C57BL/6N小鼠以15Gy剂量局部照射后按随机数字分组法分为A组(对照组)和B组(SVF处理组),每组30只。B组小鼠注射来源于B6-G/R小鼠的SVF,A组小鼠注射等量的磷酸缓冲盐溶液(PBS)。分别于SVF注射前及注射后1、3、7、14、21、28 d行活体成像(IVIS);用随机数字表法在两组小鼠中随机抽取3只,处死后切取皮肤标本于共聚焦显微镜下观察,评估SVF的分布。单因素方差分析比较组间差异。结果:SVF注射前及注射后1、3、7、14、21、28 d在IVIS下观察,光通量分别为(3.17±1.28)×107、(1.06±0.07)×1010、(9.23±0.74)×10^(9)、(4.91±0.57)×10^(9)、(2.89±0.40)×10^(9)、(1.04±0.25)×10^(9)、(2.53±0.55)×108[p/sec/cm^(2)/sr]/[μW/cm^(2)]。结果显示,SVF注射前及注射后不同时间点的荧光信号强度差异有统计学意义,F_((1.909,15.27))=85.662,P<0.01。SVF注射后第1天(P<0.01)、第3天(P<0.01)、第7天(P<0.01)、第14天(P<0.01)的荧光信号强度显著高于注射前,而第21天(P>0.05)、第28天(P>0.05)与注射前的差异无统计学意义。组织切片中绿色荧光标记的SVF分布于真皮层及皮下组织,随时间增加SVF逐渐减少。结论:本研究构建一种简便易行、高效可靠的动物模型用以示踪SVF在急性放射性皮肤损伤微环境中的转归。

Objective To develop an animal model for investigating the conversion of stromal vascular fraction(SVF)after transplantation in the microenvironment of acute cutaneous radiation injury.Methods C57BL/6N mice were exposed to 15 Gy X-ray irradiation and randomly divided into group A(control group)and group B(SVF treatment group),30 mice per group.Mice in group B were injected subcutaneously with SVF derived from B6-G/R mice,and group A were injected with PBS(phosphate buffered saline).In vivo imaging(IVIS)was performed before and day 1,3,7,14,21 and 28 after injection.3 mice from each group were euthanized at each time points after injection and full-thickness skin tissue were excised.Skin specimens were observed by Laser Scanning Confocal Microscopy to assess the distribution of SVF.One-way ANOVA was used to compare the significance of differences between groups.Results The fluorescence intensity of SVF were measured by IVIS before SVF injection[(3.17±1.28)×107,and d1(1.06±0.07)×1010,d3(9.23±0.74)×10^(9),d7(4.91±0.57)×10^(9),d14(2.89±0.40)×10^(9),d21(1.04±0.25)×10^(9),d28(2.53±0.55)×108][p/sec/cm^(2)/sr]/[μW/cm^(2)]after injection,which showed the significantly differences(F_((1.909,15.27))=85.662,P<0.01).The fluorescence signal intensity of the 1 d(P<0.01),3 d(P<0.01),7 d(P<0.01),and 14 d(P<0.01)after SVF injection were significantly higher compared to the data before injection,while 21 d(P>0.05)and 28 days(P>0.05)were no significant difference.The tissue sections showed that SVF labeled with green fluorescence was distributed in the dermis and subcutaneous tissue,and the fluorescence of SVF were gradually decreased.Conclusion We successfully constructed a model for tracking SVF as a therapy of the acute cutaneous radiation injury,which is simple,efficient,and reliable.