Tissue-committed stem cells

Kucia M, Wojakowski W, Reca R, Machalinski B, Gozdzik J, Majka M, Baran J, Ratajczak J, Ratajczak MZ (2006) The migration of bone marrow-derived non-hematopoietic tissue-committed stem cells is regulated in an SDF-1-, HGF-, and LIF-dependent manner. Arch Immunol Ther Exp (Warsz) 54 121-135... 

Further evidence for a dynamic cardiac renewal process in the adult heart comes from the recent identification of a novel population of early tissue-committed stem cells that may be part of a group of circulating progenitor cells involved in cardiac repair [40]. 

Kucia M, Ratajczak J, Ratajczak MZ. Bone marrow as a source of circulating CXCR4-I- tissue-committed stem cells. Biol CeK 2005 97 133-146. 

The value of cultured stem cells to toxicology is in their promise as a continuous source of cells that can be induced to express a chosen cell-type-specific mature phenotype. This achievement would address two current limitations in safety testing scarcity of metabolically competent human systems and use of experimental animals. Numerous culture additives and conditions have been identified that cause commitment and partial differentiation along specific lineages, such as retinoic-acid-induced neuronal commitment of mouse embryonic stem cells. However, definition of conditions that produce fully differentiated cells with cell-type-specific function quantitatively similar to that of intact tissue remains problematic and is a high-priority research area in toxicology. 

Even though these populations are localized in adult tissues having lineage-commitment and exhibiting limited plasticity and local cell markers, some of these cells are capable of de-differentiating and then becoming multipotent stem cells. 

Numerous designs have been proposed for bioreactors intended for use in the cultnre and differentiation of stem cells in their various manifestations, bnt few bioreactors that are appropriate in all respects for indnstrial or clinical use are yet available commercially. This situation reflects the fact that each disease or condition presents its own problems with respect to formnlation and development of treatment protocols for cell therapy. Efficacions cell products must be developed for each therapeutic intervention while developing protocols in sitnations where it is not clear initially which form of cell stmctnre will be most effective (e.g., undifferentiated stem cells, partially differentiated intermediate cells, lineage-committed progeny, tissue-specific mature cells, or even three-dimensional... 

The transformation of a stem cell to a fully differentiated cell within adult tissue occurs via a number of steps. The ability to control each step in the differentiation process and to manipulate exquisitely a cell s lineage commitment in vitro and in vivo would allow the selective production of different cell and tissue types and would represent a major advance in the treatment of disease. The application of chemistry to control the destiny of stem cells is a rapidly emerging discipline. The effects of small molecules to modulate biological function are rapid, and often reversible, providing an unparalleled means to control dose and timing of delivery, both critical parameters in the determination of cell fate. 

Teo BKK, Tan G-DS, Yim EKF. The synergistic effect of nanotopography and sustained dual release of hydrophobic and hydrophilic neurotrophic fadors on human mesenchymal stem cell neuronal lineage commitment. Tissue Eng A 2014 20(15—16) 2151-61. 

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