title: Characterization of dermal type I collagen of C3H mouse at different stages of the hair cycle.
abstract: Hair follicles develop or regress in accordance with the hair cycle. In this study, we partially characterized fibrillar type I collagen, the predominant component in the dermis, at two stages of the hair cycle: anagen and telogen. Skin samples were obtained from the backs of two groups of 11-week-old C3H mice: one at anagen stage induced by shaving and the other at telogen stage. The amount of neutral salt-soluble (newly synthesized) collagen obtained from anagen skin was about twofold that from telogen skin, while the level of acid-soluble collagen was not significantly different between the two groups. The degree of lysine hydroxylation of pepsinized type I collagen obtained from anagen skin was significantly higher than that in telogen (5.0% higher in alpha1 chain, and 15.6% higher in alpha2 chain). Proline hydroxylation at the anagen stage was also slightly higher than in the telogen stage. Two major collagen cross-links were found in both groups of skin; dehydro-hydroxylysinonorleucine and dehydro-histidinohydroxymerodesmosine. The concentration of the latter, a complex tetravalent cross-link, was significantly lower in anagen skin when compared with telogen skin (mean +/- SD 0.64 +/- 0. 07 vs. 0.78 +/- 0.06 mol/mol collagen). The former showed no significant difference between the two groups. In addition, a significant amount of lysyl-aldehyde (a cross-link precursor) was found in anagen (0.16 +/- 0.02 mol/mol collagen), while it was 0.12 mol/mol collagen in telogen. These results indicate that the remodelling of collagen is more active in anagen skin than in telogen, and that characteristic post-translational modifications of dermal collagen seen in anagen may play a part in facilitating an environment around hair follicles for their migration and growth.
authors.affiliation: CB7455 Dental Research Center, University of North Carolina, Chapel Hill, NC 27599-7455, USA.
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Yamauchi
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D003094:Collagen / Q000032:analysis* / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D006197:Hair / Q000254:growth & development*; D006900:Hydroxylation; D008239:Lysine / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D011392:Proline / Q000378:metabolism; D012867:Skin / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D003094:Collagen; D011392:Proline; D008239:Lysine