Expression of Bone Morphogenetic Proteins in Stromal Cells from Human Bone Marrow Long-term Culture

• Published in: The journal of histochemistry and cytochemistry 2004-09, Vol.52 (9), p.1159-1167
• Main Authors: Martinovic, Snjezana, Mazic, Sanja, Kisic, Veronika, Basic, Nikolina, Jakic-Razumovic, Jasminka, Borovecki, Fran, Batinic, Drago, Simic, Petra, Grgurevic, Lovorka, Labar, Boris, Vukicevic, Slobodan
• Format: Article
• Language: English
• Subjects: Alkaline Phosphatase - genetics; Antigens, CD - analysis; Antigens, Differentiation, Myelomonocytic - analysis; Bone Marrow Cells - cytology; Bone Marrow Cells - metabolism; Bone Morphogenetic Protein Receptors; Bone Morphogenetic Proteins - genetics; Bone Morphogenetic Proteins - metabolism; Cell Culture Techniques; Cell Division; Cells, Cultured; Clone Cells - cytology; Clone Cells - metabolism; DNA-Binding Proteins - genetics; Gene Expression Regulation; Humans; Immunohistochemistry; Platelet Endothelial Cell Adhesion Molecule-1 - analysis; Receptors, Growth Factor - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Smad Proteins; Smad1 Protein; Stromal Cells - cytology; Stromal Cells - metabolism; Trans-Activators - genetics
• ISSN: 0022-1554; 1551-5044
• DOI: 10.1369/jhc.4A6263.2004

Highly purified primitive hemopoietic stem cells express BMP receptors but do not synthesize bone morphogenetic proteins (BMPs). However, exogenously added BMPs regulate their proliferation, differentiation, and survival. To further explore the mechanism by which BMPs might be involved in hemopoietic differentiation, we tested whether stromal cells from long-term culture (LTC) of normal human bone marrow produce BMPs, BMP receptors, and SMAD signaling molecules. Stromal cells were immunohistochemically characterized by the presence of lyzozyme, CD 31, factor VIII, CD 68, S100, alkaline phosphatase, and vimentin. Gene expression was analyzed by RT-PCR and the presence of BMP protein was confirmed by immunohistochemistry (IHC). The supportive role of the stromal cell layer in hemopoiesis in vitro was confirmed by a colony assay of clonogenic progenitors. Bone marrow stromal cells express mRNA and protein for BMP-3, -4, and -7 but not for BMP-2, -5, and -6 from the first to the eighth week of culture. Furthermore, stromal cells express the BMP type I receptors, activin-like kinase-3 (ALK-3), ALK-6, and the downstream transducers SMAD-1, -4, and -5. Thus, human bone marrow stromal cells synthesize BMPs, which might exert their effects on hemopoietic stem cells in a paracrine manner through specific BMP receptors.