Prolyl 3-hydroxylase 1 null mice display abnormalities in fibrillar collagen-rich tissues such as tendons, skin, and bones.
Osteogenesis imperfecta (OI) is a skeletal disorder primarily caused by mutations in the type I collagen genes. However, recent investigations have revealed that mutations in the genes encoding for cartilage-associated protein (CRTAP) or prolyl 3-hydroxylase 1 (P3H1) can cause a severe, recessive form of OI. These reports show minimal 3-hydroxylation of key proline residues in type I collagen as a result of CRTAP or P3H1 deficiency and demonstrate the importance of P3H1 and CRTAP to bone structure and development. P3H1 and CRTAP have previously been shown to form a stable complex with cyclophilin B, and P3H1 was shown to catalyze the 3-hydroxylation of specific proline residues in procollagen I in vitro. Here we describe a mouse model in which the P3H1 gene has been inactivated. Our data demonstrate abnormalities in collagen fibril ultrastructure in tendons from P3H1 null mice by electron microscopy. Differences are also seen in skin architecture, as well as in developing limbs by histology. Additionally bone mass and strength were significantly lower in the P3H1 mice as compared with wild-type littermates. Altogether these investigations demonstrate disturbances of collagen fiber architecture in tissues rich in fibrillar collagen, including bone, tendon, and skin. This model system presents a good opportunity to study the underlying mechanisms of recessive OI and to better understand its effects in humans.
Vranka
Janice A
JA
Research Department, Shriners Hospitals for Children, Portland, Oregon 97239, USA.
Pokidysheva
Elena
E
Hayashi
Lauren
L
Zientek
Keith
K
Mizuno
Kazunori
K
Ishikawa
Yoshihiro
Y
Maddox
Kerry
K
Tufa
Sara
S
Keene
Douglas R
DR
Klein
Robert
R
Bächinger
Hans Peter
HP
D000818:Animals; D001842:Bone and Bones / Q000196:embryology / Q000378:metabolism* / Q000648:ultrastructure; D003094:Collagen / Q000737:chemistry*; D005109:Extracellular Matrix / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006868:Hydrolysis; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008854:Microscopy, Electron / Q000379:methods; D010013:Osteogenesis Imperfecta / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics* / Q000502:physiology*; D011499:Protein Processing, Post-Translational; D012867:Skin / Q000196:embryology / Q000378:metabolism* / Q000648:ultrastructure; D013710:Tendons / Q000196:embryology / Q000378:metabolism* / Q000648:ultrastructure
D003094:Collagen; D011393:Procollagen-Proline Dioxygenase