PDGF-A、PDGFR-α在单纯创伤和照射复合创伤愈合过程中伤口成纤维细胞内的表达与意义

Expression of PDGF-A and PDGFR-α in fibroblasts of usual and radiation-combined wound healing

目的 探讨局部照射对创伤愈合过程中伤口成纤维细胞PDGF A及PDGFR α表达的影响及意义。方法 将 132只Wistar大鼠分为单纯创伤组 (对照组 )和照射复合创伤组 (照射组 ) ,用免疫组织化学、原位RT PCR和图像分析方法检测两组伤口伤后 1～ 6 0d各时间点PDGF A、PDGFR α蛋白及PDGF AmRNA的表达规律。结果 局部照射使伤口愈合各阶段滞后、延长。对照组伤口成纤维细胞PDGF A和PDGFR α表达有明显的时相性 ,PDGF A在伤后 2～ 2 1d可见表达 ,5d为表达高峰 ;照射组在伤后各时间点其表达均减弱 ,且表达时相延长 ,伤后 2 8d仍有表达 ;PDGFR α在对照组于伤后 2～ 15d有表达 ,5d时达高峰 ,照射组PDGFR α表达减弱 ,但其表达时相与对照组一致。结论 照射抑制伤口成纤维细胞内源性PDGF A及PDGFR α的表达 ,表明照射使成纤维细胞自分泌PDGF A功能减弱并对外源性PDGF A的反应性减弱 ,进而导致伤口愈合延迟。

Objective To study the impact of local γ-irradiation on expression of PDGF-A and PDGFR-α in fibroblasts during healing process of usual and radiation-combined wounds. Methods 132 Wistar rats were divided into two groups:usual wound group (control group, n =66) and radiation-combined wound group (radiation group, n =66).Immunohistochemistry, in situ RT-PCR and image analysis were performed to detect the expression of PDGF-A,PDGFR-α and PDGF-A mRNA transcription in these two groups. Results Every stage of healing was delayed by radiation.The expressions of PDGF-A and PDGFR-α in the control group had temporal characteristic:PDGF-A expression was observed on days 2-21 and the highest expression was on day 5. PDGFR-α was detected on days 2-15 and its highest expression was on day 5.In the radiation group the expressions of PDGF-A were weaker than those in the control group and the expression time was prolonged,it was still observed on day 28,whereas the expression of PDGFR-α was weaker than that in the control group.But its temporal characteristic was the same as that in the control group. Conclusion Radiation can reduce the expression of PDGF-A and PDGFR-α in wound healing,indicating that it inhibits the secretion on endogenous PDGF-A and reduces the reactivity of wound to exogenous PDGF-A,thus wound healing is delayed. ;