中文摘要：

目的探讨Wnt蛋白的受体分子Frizzled4在小鼠毛囊周期中的表达、功能及其意义。方法利用实时定量PCR、RT-PCR、Westernblot和免疫荧光等技术分别检测Frizzled4mRNA和蛋白在毛囊生长期（P1d、P3d、PSd）、退化期（P16d）和静止期（P21d）中的表达。免疫荧光技术检测Frizzled4在小鼠皮肤上皮细胞JB6cD0-7b中的定位，MTY检测用抗Frizzled4抗体处理JB6cB0-7b细胞后的增殖情况。结果在毛囊生长期早期，Frizzled4mRNA和蛋白在Pld的小鼠背部皮肤中表达明显，膜表达于Bulge、毛囊外根鞘及毛球外侧。在P3d，Frizzled4蛋白表达明显上调，主要表达于Bulge、毛囊外根鞘、内根鞘、precortex、部分毛球外侧。在生长中期（PSd），Frizzled4蛋白的表达最强，集中在毛囊Bulge、外根鞘上段及内根鞘。当毛囊进入退化期（P16d），Frizzled4mRNA和蛋白的表达显著降低（P〈0．05），此时主要定位于Bugle。而在静止期，Frizzled4mRNA和蛋白表达最低（P〈0．05），只有少量Frizzled4阳性细胞出现在毛囊Bulge。免疫荧光技术检测Frizzled4蛋白同样也在JB6cD0-7b细胞膜中表达。MTr结果显示与对照组相比，10μg/mL的抗Frizzled4抗体处理JB6cD0-7b细胞后光密度值明显降低（P〈0．05），而20μg/mL的抗Frizzled4抗体处理后的光密度值降到最低（P〈0．05）。结论Frizzled4在毛囊周期中的表达具有时空特异性。伴随着毛囊的生长，Frizzled4的mRNA和蛋白水平都呈现高表达，随着毛囊的退化而表达降低，直至静止期维持低表达水平。拮抗Frizzled4蛋白的作用促使细胞增殖受到明显抑制，提示Frizzled4的表达与毛囊细胞的增殖和分化相关。

英文摘要：

Objective To investigate the expression and function of Frizzled4, a receptor of Wnt proteins, during mouse hair fol]icle cycle. Methods Q-PCR, Western blotting and immunostaining were used to detect the mRNA and protein expression of Frizzled4 in mouse hair follicle cycle at 5 time points ： the first day after birth （Pld）, P3d, P8d, P16d, and P21d. Immunostaining was used to detect the protein expression of Frizzled4 in mouse skin epithe]ium cell line JB6 cl30-7b. MTY assay was used to detect proliferation of JB6 c]30-7b cells after treatment of anti-Frizzled4 antibody. Results At Pld, mRNA and protein of Frizzled4 were both detected in mouse skin and Frizzled4 was expressed in the Bulge, out root sheath （ORS） and lateral hair bulb. At P3d, protein expression of Frizzled4 was up-regulated in the Bulge, ORS, inner root sheath （ IRS）, precortex and part of lateral hair bulb. And at middle anagen （ P8d ） , protein of Frizzled4 was expressed at the highest level in the Bulge, ORS, IRS and pre-cortex. And then at catagen （ P16d）, expression of Frizzled4 was decreased significantly （ P 〈 0.05 ） and mainly located in the Bulge while little in ORS and IRS. When hair follicles were at telegen, expression of Frizzled4 reduced to the lowest level （ P 〈 0.05 ） and was restricted in the Bulge. Frizzled4 was expressed on cell membranes of JB6 cl30-7b cells. After treatment of 10 μg/mL anti-Frizzled4 antibody, OD values decreased significantly compared with that of controls （P 〈 0.05）. After treatment of 20 μg/mL anti-Frizzled4 antibody, OD values dropped to the lowest level （ P 〈 0. 05）. Conclusion Expression of Frizzled4 is specific and spatiotemporal during hair follicle cycle. It is significantly high at anagen, reduces at catagen and maintains at a lowest level at telegen. Antagonism ofFrizzled4 inhibits significantly proliferation of keratinocytes. These results indicate that the expression of Frizzled4 is associated with the growth and differentiation of hair follicles.