Bone marrow multipotential cells

Newer strategies for stem cell identification have been developed based on the knowledge of cell functions. A primitive and multipotential subpopulation of bone marrow mononuclear cells has been identified on the basis of the intracellular presence of aldehyde dehydrogenase (ALDH). Those cells can be marked on the basis of the presence of ALDH and are called aldehyde dehydrogenase-bright cells (ALDH cells), allowing for their separation from a bone marrow aspiration mononuclear subpopulation under fluorescence-activated cell sorter (FACS) analysis. 

A large number of cells are involved in the immune response and all are derived fiom the multipotential stem cells of the bone marrow. The predominant cell is the lymphocyte but monocytes-macrophages, endothelial cells, eosinophils and mast cells are also involved with certain immune responses. The two types of immunity (humoral and cell-mediated) are dependent on two distinct populations of lymphocytes, the B cells and the T cells respectively. Both the humoral and the cell-mediated systems interact to achieve an effective immune response. 

The development of mature neutrophils in the bone marrow occurs via the differentiation of multipotential stem cells into progenitor cells that are committed to neutrophilic lineages. As this process proceeds the ability of... 

Although the major physiological role of EPO is certainly to promote red blood cell production, EPO mRNA has also been detected in bone marrow macrophages, as well as some multipotential haemopoietic stem cells. Although the physiological relevance is unclear, it is possible that EPO produced by such sources may play a localized paracrine (or autocrine) role in promoting erythroid differentiation. 

Every second of life a human must produce about 2.5 million red blood cells, about 2 million granulocytes, and many lymphocytes as well as other less numerous leukocytes. All of these arise from multipotential stem cells found in the bone marrow.376-379 Each of these stem cells divides to form one daughter stem cell and one progenitor cell.380 The progenitor cells are also stem cells but have differentiated into myeloid,381 erythroid, and lymphoid382 383 cells. 

A number of cytokines (see p. 280) stimulate the growth, differentiation and functional activity of myeloid progenitor cells. As the name implies the function of these polypeptides was defined by in-vitro colony assays of bone marrow progenitors. They have effects on all myeloid cells including the multipotential stem cells (but probably not the more immature pluripotentiai cells), intermediate progenitors and circulating mature cells. Those in clinical use are described below. 

The biological activities of IL-11 are not fully characterized, but they are similar to those of IL-6, LIF, and OSM. For example, IL-11 (1) stimulates the development of diverse hematopoietic cell lineages from bone marrow precursors (especially of early hematopoiesis), including monocytes and/or macrophages and megakaryocytes (2) is a groivth factor for plasmacytes, hematopoietic multipotential cells. 

Bianco P, Riminucci M, Kuznetsov S, et al. (1999). Multipotential cells in the bone marrow stroma Regulation in the context of organ physiology. Crit. Rev. Eukaryot. Gene Expr. 9 159-173. 

Smith, J. R., Pochampally, R., Perry, A., Hsu, S. C., and Prockop, D. J. 2004. Isolation of a highly clonogenic and multipotential subfraction of adult stem cells from bone marrow stroma. Stem Cells, 22,823-31. 

Boo L, Selvaratnam L, Tai C C et al. Expansion and preservation of multipotentiality of rabbit bone-marrow derived mesenchymal stem cells in dextran - based microcarrier spin culture. Journal of Materials Science Materials in Medidnefahead of printing)... 

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