title: Oral collagen-derived dipeptides, prolyl-hydroxyproline and hydroxyprolyl-glycine, ameliorate skin barrier dysfunction and alter gene expression profiles in the skin.
abstract: Oral supplementation with collagen hydrolysate (CH) has been shown to improve the condition of the skin in humans and experimental animals. Several hydroxyproline-containing oligo-peptides were previously detected in human peripheral blood after the ingestion of CH, and the two dipeptides, prolyl-hydroxyproline (PO) and hydroxyprolyl-glycine (OG), have been proposed to have beneficial effects on human health. When HR-1 hairless mice were fed a HR-AD diet, which lacked magnesium and zinc, transepidermal water loss (TEWL) increased and water content of stratum corneum decreased. In the present study, we investigated the effects of dietary PO and OG on skin barrier dysfunction in HR-1 hairless mice. Mice were fed a HR-AD diet with or without PO (0.15%) and OG (0.15%) for 35 consecutive days. The administration of PO and OG significantly decreased TEWL, and significantly increased water content of stratum corneum. A DNA microarray analysis of the dorsal skin revealed differences in gene expression between the group administered PO and OG and the control group. We also identified muscle-related Gene Ontology as a result of analyzing the up-regulated genes. These results suggested that the administration of PO and OG improved skin barrier dysfunction and altered muscle-related gene expression.
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama 350-0295, Japan. Electronic address: jshimizu@josai.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Shimizu
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama 350-0295, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Asami
authors.affiliation: Peptide Division, Nitta Gelatin Inc., 2-22 Futamata, Yao-shi, Osaka 581-0024, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Kataoka
authors.affiliation: Peptide Division, Nitta Gelatin Inc., 2-22 Futamata, Yao-shi, Osaka 581-0024, Japan.
authors.forename: Fumihito
authors.initials: F
authors.lastname: Sugihara
authors.affiliation: Peptide Division, Nitta Gelatin Inc., 2-22 Futamata, Yao-shi, Osaka 581-0024, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama 350-0295, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Kimira
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama 350-0295, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Wada
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado-shi, Saitama 350-0295, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mano
mesh_terms: D000284:Administration, Oral; D000818:Animals; D003094:Collagen / Q000008:administration & dosage* / Q000737:chemistry; D004032:Diet; D004151:Dipeptides / Q000008:administration & dosage* / Q000737:chemistry; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D006868:Hydrolysis; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D054792:Muscle, Striated / Q000187:drug effects / Q000378:metabolism; D059467:Transcriptome / Q000187:drug effects; D014870:Water Loss, Insensible / Q000187:drug effects*
chemical_list: D004151:Dipeptides; C575137:hydroxyprolyl-glycine; C533879:prolyl-4-hydroxyproline; D003094:Collagen
keywords: Collagen hydrolysate; DNA microarray; Hydroxyprolyl-glycine; Prolyl-hydroxyproline; Transepidermal water loss; Water content of stratum corneum