Adult bone marrow is a rich source of human mesenchymal ‘stem’ cells but umbilical cord and mobilized adult blood are not

Abstract

Summary. In postnatal life, mesenchymal stem cells (MSC) self-replicate, proliferate and differentiate into mesenchymal tissues, including bone, fat, tendon, muscle and bone marrow (BM) stroma. Possible clinical applications for MSC in stem cell transplantation have been proposed. We have evaluated the frequency, phenotype and differentiation potential of MSC in adult BM, cord blood (CB) and peripheral blood stem cell collections (PBSC). During culture, BM MSC proliferated to confluence in 10-14 d, maintaining a stable non-haemopoietic phenotype, HLA class-1 + , CD29 + , CD44 + , CD90 + , CD45 -, CD34 -and CD14 through subsequent passages. Using the colony forming unit fibroblasts assay, the estimated frequency of MSC in the BM nucleated cell population was 1 in 3AE4 · 10 4 cells. Both adipogenic and osteogenic differentiation of BM MSC was demonstrated. In contrast, CB and PBSC mononuclear cells cultured in MSC conditions for two passages produced a population of adherent, non-confluent fibroblast-like cells with a haemopoietic phenotype, CD45 + , CD14 + , CD34 -, CD44 -, CD90 -and CD29 -. In paired experiments, cultured BM MSC and mature BM stroma were seeded with CB cells enriched for CD34 + . Similar numbers of colony-forming units of granulocytes-macrophages were produced by MSC-based and standard stroma cultures over 10 weeks. We conclude that adult BM is a reliable source of functional cultured MSC, but CB and PBSC are not.

Chemotherapy-induced mesenchymal stem cell damage in patients with hematological malignancy

“…2 Cells from HDC patients display a mixed morphology in primary culture. Representative phase-contrast images of primary cultures derived from a patients who have received no prior treatment and b patients who had received prior highdose chemotherapy long-term culture conditions developed the same microscopic appearance as stroma derived from fresh marrow buffy coat samples as reported by Wexler et al [23]. All cultures were primarily seeded with hematopoietic CD34 + cells derived from the same cord blood source.…”

“…To ensure that a homogenous population of MSCs had been cultured, immunophenotyping of surface markers, using flow cytometric techniques, was carried out according to previous reports [1,23,24]. MSCs were examined using the fluorescently tagged monoclonal antibodies anti-CD105, anti-CD45, anti-CD166, anti-CD44, and anti-CD29 (BD Biosciences, Oxford, UK).…”

Mesenchymal stem cells from cryopreserved human umbilical cord blood

“…The frequency of MSC in cryopreserved UCB units has not been clearly defined. Previous studies reported that the frequency of BM-MSC in adults was one in 3.4 Â 10 4 cells, using the culture of colony forming unit-fibroblast (CFU-F) as a surrogate assay, while fresh UCB and PBSC did not produce CFU-F at all [13,21]. It is possible that MSCs in cryopreserved UCB units are present at a very low frequency relative to MSCs in BM in our samples.…”

“…It was reported that fresh UCB-derived mononuclear cells (MNCs) seeded on flasks without supportive stromal layers did not form stroma in long-term culture conditions [12]. Wexler et al [13] concluded that neither fresh UCB nor peripheral blood with stem cell mobilization contained MSCs. Another study also reported that fresh UCB did not produce mesenchymal progenitor cells [14].…”

Study of the Quantitative, Functional, Cytogenetic, and Immunoregulatory Properties of Bone Marrow Mesenchymal Stem Cells in Patients with B-Cell Chronic Lymphocytic Leukemia

“…A standard colony-forming-unit fibroblastic (CFU-F) assay was used to calculate MSC frequency within the BMMC fraction [29,30]. Briefly, day-0 BMMCs were seeded at 5 different concentrations (10 · 10 3 -200 · 10 3 cells) in 60 mm culture dishes (Gibco) and expanded for 14 days.…”