UVN对角质形成细胞生长的抑制作用及其机制研究

目的：观察UVN（混合紫外线）对角质形成细胞（keratinocytes,KC)生长的抑制作用并分析其机制。方法：将角质形成细胞株HACAT经生理剂量的UVN照射后，通过LEICA显微镜观察其形态，通过四甲基偶氮唑盐3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide,MTT]法检测其增殖情况，通过流式细胞术（FACS）分析UVN照射后不同时间HACAT的趋化因子受体CXCR2表达的改变。结果：生理剂量UVN照射HACAT后，部分细胞变圆，少量细胞脱落。照射后24h细胞的增殖受到明显抑制，此时其CXCR2的表达也明显降低，但至48h开始其增殖能力和CXCR2的表达开始恢复，72h后其增殖能力及CXCR2的表达进一步恢复，但与正常对照组间仍见差异。结论：UVN的照射可降低银屑病角质形成细胞CXCR2的表达，这可能因抑制了白细胞介素8（linterleukin 8,IL-8)等细胞生长因子对KC的促增殖作用从而对银屑病表现出一定的治疗效果。

The Inhibitory Effect of UVN and Its Mechanism on Proliferation of Keratinocyte

Objective To investigate the inhibitory effect of UVN and its mechanisms on proliferation of keratinocytes.Methods After the keratinocyte cell line HACAT was irradiated by UVN,the morphological characteristics of the cells were observed by LEICA microscope and the proliferative capacity was detected by MTT methods.The expression of CXCR2 was also assayed by flow cytometry.Results After UVN irradiation,few cells became round and quite a few cells looked like dead.The proliferative capacity and the CXCR2 expression on the cells also decreased significantly.But the most obvious decrease was detected at 24h after irradiation and then such alterations were reduced from 48h to 72h.Conclusion The downregulation of the CXCR2 expression in keratinocytes may contribute to the therapeutic effect of UVN irradiation on psoriasis as the over proliferation of keratinocytes in psoriasis often results from the combination of CXCR2 with its ligands such as interleukine 8.