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dc.contributor.authorPockwinse, Shirwin M.
dc.contributor.authorStein, Janet L.
dc.contributor.authorLian, Jane B.
dc.contributor.authorStein, Gary S.
dc.date2022-08-11T08:10:57.000
dc.date.accessioned2022-08-23T17:26:31Z
dc.date.available2022-08-23T17:26:31Z
dc.date.issued1995-01-01
dc.date.submitted2011-01-11
dc.identifier.citationExp Cell Res. 1995 Jan;216(1):244-60. <a href="http://dx.doi.org/10.1006/excr.1995.1031">Link to article on publisher's site</a>
dc.identifier.issn0014-4827 (Linking)
dc.identifier.doi10.1006/excr.1995.1031
dc.identifier.pmid7813627
dc.identifier.urihttp://hdl.handle.net/20.500.14038/49655
dc.description.abstractFetal rat calvarial-derived osteoblasts, in vitro, undergo a developmental sequence of events leading to bone tissue-like organization and osteoblast differentiation. Previous studies have documented temporal expression of genes reflecting stages of osteoblast phenotype development in relation to tissue organization. Two steroid hormones are known to modify the developmental sequence; 1,25(OH)2D3 can block differentiation when added to proliferating cells, while glucocorticoid addition to proliferating cultures increases the population of cells competent to produce a bone-like matrix and accelerates the differentiation time course. We have addressed the mechanisms contributing to these observations at the single cell level by analysis of a growth-related gene (H4 histone which is coupled with DNA synthesis) and matrix-associated genes (collagen, osteopontin, and osteocalcin) in hormone-treated cells. Our results demonstrate (1) a window of responsiveness for modifications in phenotype development; (2) distinct morphological changes and selective modifications in gene expression in response to both hormones as a function of whether the cell is proliferating or differentiated; and (3) location of the cell with respect to the mineralized nodule was a contributing factor to the levels of gene expression and hormonal responses. In response to vitamin D, surface osteoblasts associated with the nodules became flattened, elongated, and aligned, reminiscent of a bone lining cell. In glucocorticoid-treated cultures, proliferating cells became cuboidal and nodule-associated differentiated cells were approximately one-third the size of control osteoblasts. We also find subsets of hormone-responsive cells in the proliferating cultures in response to glucocorticoid but not vitamin D. In postproliferative cultures, both hormones increased osteocalcin mRNA in the more differentiated osteoblasts associated with the mineralized matrix but no induction occurred in monolayer internodular cells. Osteopontin was induced by glucocorticoid in a larger population of cells. Thus, our studies at the single cell level show selective morphological changes and changes in the level of gene expression supporting the hypothesis that hormones have differential effects on osteoblasts in relation to their stage of phenotype development.
dc.language.isoen_US
dc.relation<a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&list_uids=7813627&dopt=Abstract">Link to Article in PubMed</a>
dc.relation.urlhttp://dx.doi.org/10.1006/excr.1995.1031
dc.subjectAnimals
dc.subjectCell Differentiation
dc.subjectCell Division
dc.subjectCell Size
dc.subjectCells, Cultured
dc.subjectCholecalciferol
dc.subjectCollagen
dc.subjectDexamethasone
dc.subjectGene Expression Regulation, Developmental
dc.subjectHistones
dc.subjectIn Situ Hybridization
dc.subjectOsteoblasts
dc.subjectOsteocalcin
dc.subjectOsteogenesis
dc.subjectOsteopontin
dc.subjectPhenotype
dc.subjectRNA, Messenger
dc.subjectRats
dc.subjectSialoglycoproteins
dc.subjectSkull
dc.subjectCell Biology
dc.titleDevelopmental stage-specific cellular responses to vitamin D and glucocorticoids during differentiation of the osteoblast phenotype: interrelationship of morphology and gene expression by in situ hybridization
dc.typeJournal Article
dc.source.journaltitleExperimental cell research
dc.source.volume216
dc.source.issue1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/stein/84
dc.identifier.contextkey1724126
html.description.abstract<p>Fetal rat calvarial-derived osteoblasts, in vitro, undergo a developmental sequence of events leading to bone tissue-like organization and osteoblast differentiation. Previous studies have documented temporal expression of genes reflecting stages of osteoblast phenotype development in relation to tissue organization. Two steroid hormones are known to modify the developmental sequence; 1,25(OH)2D3 can block differentiation when added to proliferating cells, while glucocorticoid addition to proliferating cultures increases the population of cells competent to produce a bone-like matrix and accelerates the differentiation time course. We have addressed the mechanisms contributing to these observations at the single cell level by analysis of a growth-related gene (H4 histone which is coupled with DNA synthesis) and matrix-associated genes (collagen, osteopontin, and osteocalcin) in hormone-treated cells. Our results demonstrate (1) a window of responsiveness for modifications in phenotype development; (2) distinct morphological changes and selective modifications in gene expression in response to both hormones as a function of whether the cell is proliferating or differentiated; and (3) location of the cell with respect to the mineralized nodule was a contributing factor to the levels of gene expression and hormonal responses. In response to vitamin D, surface osteoblasts associated with the nodules became flattened, elongated, and aligned, reminiscent of a bone lining cell. In glucocorticoid-treated cultures, proliferating cells became cuboidal and nodule-associated differentiated cells were approximately one-third the size of control osteoblasts. We also find subsets of hormone-responsive cells in the proliferating cultures in response to glucocorticoid but not vitamin D. In postproliferative cultures, both hormones increased osteocalcin mRNA in the more differentiated osteoblasts associated with the mineralized matrix but no induction occurred in monolayer internodular cells. Osteopontin was induced by glucocorticoid in a larger population of cells. Thus, our studies at the single cell level show selective morphological changes and changes in the level of gene expression supporting the hypothesis that hormones have differential effects on osteoblasts in relation to their stage of phenotype development.</p>
dc.identifier.submissionpathstein/84
dc.contributor.departmentDepartment of Cell Biology
dc.source.pages244-60


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