Abstract: Abstract：Objective In C57 young mice and 34-month-old senile mice, β-catenin expression in hair follicle was compaired between the two age groups to investigate the relationship between β-catenin and mice hair follicle senescence. Methods The expression pattern of β-catenin in hair follicles of two age groups of C57 mice was examed by immunofluorescence, RT-PCR, and Western blot. Results Compaired to young mice, both β-catenin mRNA and protein expression levels were upregulated in old mice hair follicle at various stages of hair cycle. In the anagen skin of 34months old mice, β-catenin protein expressions were at the level of 0.9024±0.0167, significantly higher then the level in the anagen skin of 35 days old mice（0.8012±0.0184）. In the telogen skin of 34months old mice, β-catenin protein expressions were 0.6348±0.0241, significantly higher then the level in the telogen skin of 23 days old mice（0.6348±0.0241）（P＜0.05）.β-catenin protein distribution was localized at the up-portion of outer root-sheath and Bulge cells, while the nuclear expression was obviours. No apparente difference of the β-catenin expression pattern was observed in various stages of hair cycle in senile mice.Conclusion Compaired to young mice, in senile mice hair follicle, the changes of β-catenin expression pattern, including the expression level, periodicity and localization, may contribute to the senescent poliosis.

Key words: β-catenin, senescence, poliosis