Comparative Analysis of Hematopoiesis Supporting Capacity and Matrix Remodeling of Bone Marrow Stromal Cells Isolated From Patients with Myeloproliferative Neoplasms

• Published in: Blood 2012-11, Vol.120 (21), p.2864-2864
• Main Authors: Schneider, Rebekka K, Leisten, Isabelle, Ziegler, Susanne, Schumacher, Anne, Fahrenkamp, Dirk, Mueller-Newen, Gerhard, Crysandt, Martina, Jost, Edgar, Knuechel, Ruth, Brümmendorf, Tim H, Ziegler, Patrick
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V120.21.2864.2864

Abstract 2864 Myeloproliferative neoplasms (MPN) are clonal disorders characterized by excessive production of mature blood cells and secondary stromal changes in the bone marrow leading to myelofibrosis. The role of a number of fibrogenic cytokines derived from megakaryocytes or monocytes in driving reactive secondary responses of bone marrow stroma cells (BMSC) in fibrosis has been repeatedly discussed. The aim of this study is the comparative analysis of BMSC from MPN patients and non-MPN donors in regard to hematopoietic stem and progenitor cell supporting capacity, extracellular matrix (ECM) remodeling in 3D collagen-based scaffolds as well as their in situ localization in the bone marrow niche. BMSC from bone marrow routine aspirates were obtained from patients diagnosed with chronic myeloid leukemia (CML; n=5), essential thrombocythemia (ET; n=5) and polycythemia vera (PV; n=5) and compared to BMSC isolated from control BM (untreated initial diagnosis of non-Hodgkin′s lymphoma or from patients undergoing orthopedic joint replacement surgery). BMSC cultures from prefibrotic MPN patients (as determined by reticulin staining) were established and fulfilled MSC criteria according to common consensus comparable to BMSC cultures from control individuals. As BMSC have been shown to support hematopoiesis in vitro, we compared their constitutive production of hematopoietic-affiliated cytokines. BMSC from MPN and non-MPN patients expressed IL-7, M-CSF, FLT3-L, IL-6, TPO and LIF in the following order: control BMSC > ET BMSC > PV BMSC > CML BMSC. In myeloid colony formation unit (CFU) assays using healthy CD34+ hematopoietic stem and progenitor cells as readout, myeloid CFU activity was highest in the supernatant of control BMSC suggesting a decrease of hematopoiesis supporting capacity in BMSC from MPN patients. When activated through contact with the collagenous matrix in 3D scaffolds, only BMSC from ET (in 3 of 5 cases studied) or CML (1/5) patients extensively remodeled and significantly contracted the collagenous matrix. A significant up-regulation of ECM proteins –fibronectin, collagen type I, collagen type IV, laminin and osteopontin - detected by qtRT-PCR and immunohistochemistry was seen in BMSC from MPN-patients. To evaluate if BMSC contribute to ECM remodeling in vivo we analyzed fibronectin deposition in corresponding bone punches of ET patients. Co-stainings with the recently identified BMSC markers CD271 and CD146 revealed that BMSC in ET patient