ABSTRACT
OBJECTIVES: The present study describes two newly developed N-terminal pro-peptides of collagen type I (PINP) competitive enzyme-linked immunosorbent assays (ELISAs) for the assessment of corresponding PINP epitopes in the rat- and human species. METHODS: Monoclonal antibodies were raised against corresponding rat and human PINP sequences and competitive assays were developed for each species. They were evaluated in relevant pre-clinical or clinical studies. RESULTS: The antibody characterizations indicated that PINP indeed was recognized. Technical robust assays were obtained. Rat PINP and tALP showed similar patterns in the gold standard osteoporosis rat ovariectomized (OVX) model. No liver contribution was observed in the liver fibrosis rat bile duct ligation model (BDL). In an osteoporosis study, the human serum PINP levels were significantly decreased after ibandronate treatment compared to placebo. CONCLUSIONS: The two corresponding PINP assays were specific and these bone turnover markers may improve translational science for the evaluation for bone-related diseases.
Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Epitopes/immunology , Peptide Fragments/blood , Peptide Fragments/immunology , Procollagen/blood , Procollagen/immunology , Aged , Amino Acid Sequence , Animals , Blotting, Western , Bone Density Conservation Agents/pharmacology , Calibration , Clone Cells , Demography , Diphosphonates/administration & dosage , Diphosphonates/pharmacology , Female , Humans , Ibandronic Acid , Molecular Sequence Data , Osteocalcin/blood , Ovariectomy , Peptide Fragments/chemistry , Placebos , Postmenopause/blood , Postmenopause/drug effects , Procollagen/chemistry , RatsABSTRACT
This study was performed to evaluate angiogenic responses of angiopoietin-1 (Ang1) in vivo after adenovirus-mediated gene transfer in the periadventitial space of the rabbit carotid arteries using a collar technique. Adenoviruses encoding LacZ and vascular endothelial growth factor (VEGF) receptor-1-Ig fusion protein (VEGF-R1-Ig) adenoviruses were used as controls. Increased neovessel formation was seen in adventitia of the Ang1 transduced arteries 7 days after the gene transfer. Neovessels in the Ang1 transduced arteries were large in size and well perfused. Ang1 binds to Tie2 (tyrosine kinase with immunoglobulin and epidermal growth factor homology domain) receptors, which were expressed in the endothelium of the neovessels. When VEGF-R1-Ig was used with Ang1, it resulted in a decrease in the number of neovessels, which implies that VEGF-A or some other VEGF-R1 ligand(s) play a crucial role in angiogenesis occurring in response to Ang1. There were no significant differences in the total number of capillaries in the adventitia of the VEGF-R1-Ig transduced arteries as compared to LacZ controls. Neointima formation was not increased in the Ang1 transduced arteries as compared to the controls. We conclude that in the periadventitial space Ang1 shows angiogenic activity and is a potentially useful factor for the induction of therapeutic vascular growth in vivo.
