Annexin A1 (ANXA1), a calcium-dependent phospholipid binding protein expressed in animals, plants and microorganisms, participates in various cellular physiological activities. Previous proteomics analysis indicates that the level of ANXA1 in mice dorsal skin changes during hair growth cycle, we speculate that ANXA1 may play an important role in hair follicle (HF) development. Thus, Anxa1 knock-out (KO) and over-expression (OE) mice were constructed to test its function. Our results showed that in addition to the diameter of HF and hair shaft, ANXA1 could participate in hair growth by affecting the density of HF, and the proliferation of hair follicle stem cells (HFSCs). Meanwhile, molecular analysis showed that EGF signaling pathway is involved in the function of ANXA1. The expression of Anxa1 is negatively correlated with the levels of Egf, Notch1, Mkk7, and phosphorylated AKT1 and ERK/2 proteins. The levels of Egf, Notch1, Mkk7 and phosphorylation of AKT1 and ERK/2 increased in Anxa1 KO mice but decreased in Anxa1 OE mice. Taken together, our results suggested that ANXA1 could affect the hair growth by regulating the HFSCs proliferation through EGF signaling pathway.

Annexin A1（ANXA1）是一种在动物，植物和微生物中表达的钙依赖性磷脂结合蛋白，它参与各种细胞生理活动。先前的蛋白质组学分析表明，在小鼠毛发生长周期中，小鼠背部皮肤中ANXA1的水平发生了变化，我们推测ANXA1可能在毛囊（HF）的发育中起重要作用。因此，构建了Anxa1基因敲除（KO）和过度表达（OE）小鼠以测试其功能。我们的结果表明，除了HF的直径和发干以外，ANXA1还可以通过影响HF的密度和毛囊干细胞（HFSC）的增殖来参与头发的生长。同时，分子分析表明EGF信号通路参与ANXA1的功能。Anxa1的表达与Egf，Notch1，Mkk7以及磷酸化的AKT1和ERK / 2蛋白水平呈负相关。在Anxa1 KO小鼠中，Egf，Notch1，Mkk7的水平以及AKT1和ERK / 2的磷酸化水平升高，但在Anxa1 OE小鼠中降低。两者合计，我们的结果表明ANXA1可能通过调节EGF信号传导途径的HFSCs增殖来影响头发的生长。