Non‐hematopoietic human bone marrow contains long‐lasting, pluripotential mesenchymal stem cells

Abstract

Mesenchymal stem cells (MSC) are considered as potential agents for reconstructive and gene-targeting therapies since they differentiate into various cell-lineages, exhibit an extended survival once injected into a host, and can easily be transfected with engineered DNA. MSC are essentially isolated from hematopoietic bone marrow (BM), a process that is rather invasive and may raise ethical concerns. In an attempt to find an alternative source, we evaluated whether non-hematopoietic (nh)BM recovered from femoral heads of patients undergoing hip arthroplasty contained MSC. Ex vivo, 99% of nhBM cells were CD45(+) leukocytes. After culture, leukocytes were replaced by a homogeneous layer of adherent CD45(-) CD14(-) CD34(-) CD11b(-) CD90(+) HLA-ABC(+) cells. Culture doubling time (mean = 4 days, range 1.6-6.7 days) was not correlated with patient age (27-81 years, n = 16). Amplified cultures supported long-term hematopoiesis, and could be differentiated in vitro into adipocytes and chondrocytes. Moreover, a small fraction of nhBM cells spontaneously expressed MyoD1 and formed myotubes, suggesting that myogenic differentiation also occurred. nhBM contained clonogenic cells whose frequency (1/13,000), doubling time (2.1 days), and maximal amplification (up to 10(6)-fold) were not age-related. All 14 clones analyzed (from five patients, ages 27-78 years) differentiated into at least one mesenchymal lineage, and 66% were bipotential (n = 8/12), or tripotential (n = 2/3). In conclusion, nhBM contains pluripotential mesenchymal progenitors which are similar to hematopoietic BM-derived MSC, and whose biological functions are not altered by aging. Furthermore, if MSC-based therapies hold their promises, nhBM may become the source of choice for responding to the increasing demand for MSC.

Biologic Characteristics of Fibrous Hamartoma from Congenital Pseudarthrosis of the Tibia Associated with Neurofibromatosis Type 1

“…In the current study, we characterized the fibrous hamartoma cell phenotype, and found it to be CD441/CD1051/CD45-/ CD14-, which is consistent with the immunophenotype of mesenchymal lineage cells 17,18 . This immunophenotype was shared by tibial periosteal cells, which were presumed to represent normal control of fibrous hamartoma tissue.…”

“…CD44 (matrix receptor) and CD105 (transforming growth factora [TGF-a] coreceptor) were used as positive mesenchymal lineage cell markers, and CD45 and CD14 (hematopoietic lineage markers) were used as negative markers 17,18 . Cells (5 · 10 5 ) from each specimen were incubated with rat anti-human CD44 monoclonal antibody (eBioscience, San Diego, California) and mouse anti-human CD45 antibody (DakoCytomation, Glostrup, Denmark).…”

Multipotent Stem Cells in Human Corneal Stroma

“…ABCG2-expressing SP cells have frequently been reported to display the ability to express differentiated markers of multiple tissues in response to different environmental stimuli [5,6,9,10,12,15,24,28,30,31]. Although the biological implications of such multipotency are not yet fully understood, this unusual property has become a useful means of confirming the stem-like nature of these cells.…”

“…We examined this property in the cloned SP cells by culturing them as a pellet in medium found to induce chondrogenesis in adult stem cells [25,28]. Under these conditions, mRNA and protein for several cartilage-specific extracellular matrix molecules could be detected (Fig.…”

Randomized Clinical Trials in Stem Cell Therapy for the Heart - Old and New Types of Cells for Cardiovascular Repair

“…It is a complex organ with a specific geometric organization and an intrincate system of cell-to-cell interaction and signaling, and it contains several cell subpopulations: 1) differentiated cells like stromal supporting mesenchymal cells, vascular cells, adipocytes, osteoblasts and osteocytes, and 2) progenitor cells. The most important subpopulation is the bone marrow mononuclear cell (BMMC) fraction, that includes mesenchymal stem cells (MSC), hematopoietic progenitor cells (HPC) and endothelial progenitor cells (EPC) (Shizuru et al, 2005;Suva et al, 2004). It also contains more committed cell lineages, such as natural killers, T and B lymphocytes.…”