Bone marrow stromal proteoglycan heterogeneity: phenotypic variability between cell lines and the effects of glucocorticoid.
Hematopoiesis in vivo is dependent upon the interaction of hematopoietic stem cells with a complex microenvironment, of which stromal proteoglycans are an important functional component. Certain bone marrow stromal cell lines provide a microenvironment that supports hematopoiesis in vitro, a function that is dependent upon glucocorticoid supplementation. Proteoglycan synthesis in the hematopoietic-supportive D2XRII, Bl6 and 14F1 bone marrow stromal cell lines was studied by 35S-sulfate precursor labelling and ion-exchange separation, followed by isopyknic CsCl density centrifugation and gel filtration HPLC. The effects of glucocorticoid were also investigated. A similar pattern of proteoglycan heterogeneity was observed in all three cell lines, although there was considerable quantitative variation. All cultures synthesized three species of chondroitin/dermatan sulfate (CS/DS) proteoglycans: DS1, excluded from a Bio-Sil TSK-400 HPLC column, and DS2, eluting at Kd = 0.31, were present mainly in the culture media. The smallest (DS3) eluted at Kd = 0.63 and was present mainly in the cell layers. CS/DS species were the major proteoglycans in all cultures. Hydrocortisone-free cultures also synthesized heparan sulfate (HS) proteoglycans, including a cell-associated form (HS1), partially excluded from the TSK-400 column, and a secretory form (HS2), eluting at Kd = 0.15. D2XRII cells also secreted an apparently-unique, high-density proteoglycan, Kd = 0.65, into the culture medium. Hydrocortisone at 10(-6) M virtually abolished HS proteoglycan synthesis in all three cell lines, and altered the pattern of CS/DS proteoglycans in the culture media, increasing the quantity of DS1 and DS3, and reducing the quantity of DS2.
Bentley
S A
SA
Department of Pathology, University of North Carolina School of Medicine, Chapel Hill 27514.
Kirby
S L
SL
Anklesaria
P
P
Greenberger
J S
JS
D000818:Animals; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism*; D002460:Cell Line / Q000187:drug effects; D002499:Centrifugation, Density Gradient; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003871:Dermatan Sulfate / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000378:metabolism; D006854:Hydrocortisone / Q000494:pharmacology; D046911:Macromolecular Substances; D051379:Mice; D010641:Phenotype; D011509:Proteoglycans / Q000378:metabolism*; D013431:Sulfates / Q000378:metabolism
D011508:Chondroitin Sulfate Proteoglycans; D005938:Glucocorticoids; D046911:Macromolecular Substances; D011509:Proteoglycans; D013431:Sulfates; C032649:dermatan sulfate proteoglycan; D003871:Dermatan Sulfate; D006854:Hydrocortisone