Cellular Distribution of Platelet-Derived Growth Factor, Transforming Growth Factor-(beta), Basic Fibroblast Growth Factor, and Their Receptors in Normal Bone Marrow

We performed an immunohistochemical study on 5 normal marrow samples and 3 fibrotic marrow samples to investigate the cellular distribution of various isoforms of platelet-derived growth factor (PDGF), transforming growth factor-(beta) (TGF(beta)), basic fibroblast growth factor (bFGF), and their corresponding receptors. Immature hematopoietic precursors strongly expressed PDGF-B, all the TGF-(beta) isoforms, PDGFR(beta), TGF(beta)RI and II, and FGFR1, 3, and 4. Megakaryocytes stained primarily for PDGF-B, TGF-(beta)2-3, and PDGFR(beta). Histiocytes displayed intense TGF-(beta)1, bFGF, and FGFR2 expression. Fibroblasts and endothelial cells carried receptors for all the aforementioned cytokines. The last 2 cell types also expressed the ligand cytokines to varied degrees.