title: Proteoglycan synthesis in two murine bone marrow stromal cell lines.
abstract: There is evidence indicating that stromal proteoglycans are an important functional component of the hematopoietic microenvironment. Proteoglycan synthesis was therefore investigated in the MS3-2A and D2XRII hematopoietic stromal cell lines. These lines differ in their capacity to support hematopoiesis in vitro, D2XRII supporting in vitro hematopoiesis, whereas MS3-2A does not. Cells were labeled with 35S-sulfate as precursor, and 4 mol/L guanidine HCl extracts of cells and media were analyzed by ion-exchange chromatography, cesium chloride density gradient centrifugation, and molecular sieve chromatography. Proteoglycans were further examined by enzymatic and chemical digestions. MS3-2A cells produced at least three proteoglycan species. Two chondroitin/dermatan sulfate (CS/DS) proteoglycans, Kav = 0.40 and Kav = 0.68 on Sepharose CL-2B, were present primarily in the medium. The respective glycosaminoglycan molecular weight (mol wt) values were 38 kd and 40 kd. A heparan sulfate (HS) proteoglycan of Kav = 0.58 and glycosaminoglycan mol wt 36 kd was present primarily in the cell layer extract. D2XRII cells synthesized two HS proteoglycans. The larger (Kav = 0.45; glycosaminoglycan mol wt, 30 kd) was of low density on gradient centrifugation and more prominent in the cell layer extracts, whereas the smaller (Kav = 0.68; glycosaminoglycan mol wt, 38 kd) was dense and present mainly in the culture medium. A single CS/DS proteoglycan species of Kav 0.78 and average glycosaminoglycan of mol wt 18 kd was present in roughly equal amounts in the medium and in the cell layer. MS3-2A and D2XRII thus appear phenotypically distinct with respect to proteoglycan synthesis. These differences are discussed in relation to the microenvironmental function of bone marrow stromal elements.
authors: Department of Pathology, School of Medicine, University of North Carolina, Chapel Hill 27514.
authors: S L
authors: SL
authors: Kirby
authors: S A
authors: SA
authors: Bentley
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism*; D001854:Bone Marrow Cells; D002460:Cell Line; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D003470:Culture Media; D005110:Extracellular Space / Q000502:physiology; D006410:Hematopoiesis; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis*
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D003470:Culture Media; D019812:Heparan Sulfate Proteoglycans; D006497:Heparan Sulfate; D011509:Proteoglycans