Development of a Highly Sensitive, High-Throughput, Mass Spectrometry-Based Assay for Rat Procollagen Type-I N-Terminal Propeptide (PINP) To Measure Bone Formation Activity
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- 作者：Bomie Han ; Marci Copeland ; Andrew G. Geiser ; Laura V. Hale ; Anita Harvey ; Yanfei L. Ma ; Connie S. Powers ; Masahiko Sato ; Jinsam You ; John E. Hale
- 刊名：Journal of Proteome Research
- 出版年：2007
- 出版时间：November 2007
- 年：2007
- 卷：6
- 期：11
- 页码：4218 - 4229
- 全文大小：301K
- 年卷期：v.6,no.11(November 2007)
- ISSN：1535-3907
文摘
Type-I procollagen aminoterminal propeptide (PINP) is a useful biomarker for bone formation activitythat is used to monitor treatment of bone disorders including osteoporosis. Studies with human patientsunder long-term therapy for osteoporosis by daily injection of parathyroid hormone (PTH) demonstratedthat the circulating level of PINP at 3 months of treatment, measured by radioimmunoassay, was agood predictor for bone mineral density (BMD) at 18 months. It is important to have PINP assays forother species to elucidate processes of bone formation and for the development of new therapeuticoptions that can enhance bone formation activity. Currently, only a human PINP radioimmunoassay iscommercially available for clinical use, which may not be cross reactive with PINP from other species.For example, rat PINP has little amino acid sequence homology to human PINP. Therefore, we developeda new, highly sensitive, high-throughput mass spectrometry-based assay for PINP from rat plasma orserum that does not rely on antibody reagents. Circulating levels of PINP showed age-dependentchanges in rats. Prednisolone treatment, which is known to retard bone formation activity, led to asignificant decrease in PINP, whereas PTH treatment dose-dependently increased PINP. The throughputof the assay parallels that of most antibody-based assays so that it can handle a large number of samplesthat are generated from preclinical animal studies. PINP in rats may serve as a biomarker for boneformation activity, and this assay could be instrumental in studying bone physiology in rat experimentalmodels.