New Insight into the Relationship between TGF-A Superfamily andNoggin in Hair Cycle

Members of TGF-â superfamily participate in controlling hair apoptosis, and the roles of those factors in the hair cycle have not been sufficiently clear. BMPswhich belong to the TGF-â superfamily also play critical roles in governing hair growth. In the process of controlling hair growth through the interacting between BMPs and noggin, noggin not only acts as an inhibitor of BMP-2 and 4 but influents the wavy expressions of BMP-2 and 4. Furthermore, BMPs are similar with TGF-â1, 2, 3 in structures and biologic characters. We present the positions of TGF-â1, 2, 3, and among those factors TGF-â1, 2 have some consistency with the positions of noggin in the hair regeneration cycles. Furthermore, TGF-â1, 2 are known as apoptosis-inducing factors, they can cease the cell proliferation through downstream signaling factors. After checking the positions of TGF-â1, 2 and Noggin,we inferred that TGF-â1, 2 may induce hair enter into catagen phase by inhibiting cell division or noggin expression, the wavy expressions of TGF-â1, 2 probably specify the hair cycle.