微波辐射减轻瘢痕形成的疗效及其作用机制研究

The effects of microwave irradiation on the proliferation of cultured human keloid-derived fibroblasts and the mechanism involved

目的探讨微波辐射对原代培养的人瘢痕疙瘩来源的成纤维细胞增殖活性的影响，进而分析微波辐射后成纤维细胞的胶原蛋白合成的变化及相关信号的激活情况。方法将瘢痕成纤维细胞分为对照组（自然生长无任何处理）、10mW／cm2微波辐射组和20mW／cm2微波辐射组，然后再根据辐射时间，将10mW／cm2微波辐射组和20mW／cm2微波辐射组分为辐射5min、15min、30min各3个亚组。采用3-（4，5-二甲基噻唑-2）-2，5-二苯基四氮唑溴盐法（MTT）测定成纤维细胞的生长情况。采用Western blot方法分析微波辐射后对细胞I型胶原蛋白表达水平的影响。采用抗磷酸化形式的c—Jun氨基末端激酶（JNK）抗体，通过Western blot方法观察微波辐射后瘢痕来源的成纤维细胞JNK磷酸化（pJNK）的情况。结果辐射后，10mW／cm2微波辐射组3个亚组的瘢痕成纤维细胞增殖率与对照组比较，差异均无统计学意义（P〉0．05）；20mW／cm2微波辐射组3个亚组的瘢痕成纤维细胞增殖率明显受到抑制，与对照组和10mW／cm2微波辐射组相同时间点比较，差异均有统计学意义（P〈0．05），且20mW／cm2微波辐射组各时间点间两两比较，差异均有统计学意义（P〈0．05）。辐射后，20mW／cm2微波辐射组的瘢痕成纤维细胞中I型胶原的表达量显著降低，其降低程度随着微波辐射时间的延长而增加。辐射后，20mW／cm2微波辐射组各时间点的瘢痕成纤维细胞内JNK信号通路的激活水平均显著上调，且分别与对照组比较，差异均有统计学意义（P〈0．05）。结论20mW／cm2强度的微波辐射可显著抑制瘢痕成纤维细胞的增殖，且辐射时间越长抑制效果越明显；20mW／cm2强度的微波辐射可显著抑制胶原的表达，并通过激活JNK信号转导通路而起到减轻瘢痕形成的作用。

Objective To explore the effects of microwave irradiation on the proliferation of keloid-derived fibroblasts so as to analyze the expression of collagen-1 and the activation of the signaling pathway involved. Methods Cells from a human kcloid sear were cultured in vitro and randomly divided into a control group without any intervention, a 10 mW/cm2 microwave irradiation （10-MI） group and a 20 mW/cm2 microwave irradiation （20-MI） group. Aliquots of the latter 2 groups were irradiated at their corresponding intensities for 5 rain, 15 rain and 30 min. The growth of fibroblasts was evaluated using MTT assay. The expression of collagen-1 and changes in the phosphorylation of protein JNK were detected using western blotting. Results Compared with the control group, no significant differences in the average growth of the keloid-derived fibroblasts were observed in the 10-MI group, but significant differences were observed in the 20-MI group and among the three sub-groups irradiated for different durations. The expression of type 1 collagen was significantly down-regulated after irradiation in a time-dependent manner. After microwave radiation at 20 mW/cm2 , JNK was significantly activated compared to the control group at the different time points. Conclusions Microwave irradiation at 20 mW/cm2 can significantly inhibit the proliferation of keloid-derived fibroblasts and the down-regulation is correlated with the irradiation＇s duration. It can also significantly inhibit collagen-1 expression and relieve scar formation through activating the JNK signal pathway.