The Study on Biological Function of Keratin 26, a Novel Member of Liaoning Cashmere Goat Keratin Gene Family.

In our research, we explored the relationship between Keratin 26 and the regulation of fine hair, BMP signaling pathway, MT, FGF5, and IGF-I. The result of hybridization in situ revealed that Keratin 26 was specially expressed in cortex of skin hair follicles; the result of immunohistochemistry indicated that Keratin 26 was expressed in internal root sheath, external root sheath. Then, Real-time quantitative PCR results showed that relative expressive quantity of Keratin 26 was 1.08 or 3.3 × greater in secondary follicle than primary follicle during anagen or catagen; the difference during anagen was not remarkable (p>0.05), however, that of catagen was extremely significant (p<0.01). Relative expressive quantity of Keratin 26 increased during telogen; the difference was extremely significant (p<0.01). Moreover, after Noggin expression interference using RNAi technology, we found that relative expressive quantity of Keratin 26 extremely remarkably declined (p<0.01); after K26 overexpression, we found that relative expressive quantity of Noggin extremely remarkably increased (p<0.01). We detected expressive quantity change of Keratin 26 and Keratin 26 using Real-time quantitative PCR and immunofluorescence technologies after fibroblasts were treated with MT, FGF5 or IGF-I; the results indicated that MT and FGF5 played a positive role in Keratin 26 and Keratin 26 expression, IGF-I played a negative role in Keratin 26 expression, positive role in Keratin 26 expression. The results above showed that Keratin 26 could inhibit cashmere growth, and was related to entering to catagen and telogen of hair follicles; Keratin 26 and BMP signaling pathway were two antagonistic pathways each other which could inhibit growth and development of cashmere; MT, FGF5 and IGF-I could affect expression of Keratin 26 and Keratin 26, and Keratin 26 was one of the important pathways that MT induced cashmere production in advance, FGF5 regulated cashmere growth and IGF-I promoted cashmere growth and development.