Osteoblasts enzymatically isolated from newborn @entity35 calvariae show various phenotypes including formation of mineralized bone nodules in culture. We investigated the temporal changes in osteoblast phenotype in these cells up to day 20 in culture. These cells formed unmineralized nodules by day 5. Mineralization was observed at the center of nodules by day 10, and nodules became larger on day 15. The nodules were surrounded by numerous alkaline phosphatase (ALP)-positive cells. ALP activity gradually increased by day 20. @entity4727 ( @entity4727 ) responsiveness increased with time in culture. Osteoblasts produced no @entity9356 by day 10, but its synthesis was detected from day 15. These cells expressed substantial levels of ALP and @entity4727 /PTHrP receptor mRNAs as early as day 5 in culture, but very weak expression of @entity9356 mRNA on day 5. The levels of expression of these transcripts increased with time in culture. In situ hybridization demonstrated that @entity4727 /PTHrP receptor and @entity9356 mRNAs were strongly expressed in nodules, but the former appeared much earlier than the latter. @entity2095 and @entity17412 mRNAs also appeared in the cells forming nodules. Immunohistochemical analysis demonstrated that cells expressing either @entity48141 or their receptors (BMPR-IA, BMPR-IB, and @entity24535 ) preferentially appeared in nodules. These observations suggested that BMPs play an important role in the formation of mineralized bone nodules in an autocrine and/or paracrine fashion in these cells. The present study confirmed that osteoblasts enzymatically isolated from newborn @entity35 calvariae are a useful tool for studying the differentiation process of osteoblasts.

Changes in osteoblast phenotype during differentiation of enzymatically isolated XXXX calvaria cells.

@entity48141 :: ('29373;25296', 'Gene') :: ['BMP-2/4'] @entity24535 :: ('140590(Tax:10116)', 'Gene') :: ['BMPR-II'] @entity17412 :: ('25296(Tax:10116)', 'Gene') :: ['BMP-4'] @entity9356 :: ('81613(Tax:10116)', 'Gene') :: ['osteocalcin'] @entity2095 :: ('29373(Tax:10116)', 'Gene') :: ['BMP-2'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity4727 :: ('24694(Tax:10116)', 'Gene') :: ['PTH', 'Parathyroid hormone']
@entity35 :: (10116,Species) :: ['rat']
