Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 135

All adult stem cells—whether yielded from blood, bone marrow, or tissue—share multiple features that make them an interesting choice in the field of cell-based regeneration. Trials have shown that there is little risk associated with human therapeutic application. To demonstrate the essentiality of these cells in organisms with a prolonged life, the hematopoietic system of the human body is a good example. Highly specialized cells or mature blood cells are short-lived, such as red blood cells, which live for approximately 120 days and are then eliminated.

Billions of red blood cells circulate in our system and are destroyed every day; the blood cell source must be limitless to meet the demand, which can have the hematopoietic stem cells as the root. It produces more hematopoietic stem cells along with differentiated “progenitor cells,” which then further differentiate into all lineages of mature blood cells (white and red). Bone marrow serves as the major source of adult hematopoietic stem cells alongside the umbilical cord blood of newborns. Hematopoietic stem cells become permanently settled in bone marrow, but they can leave bone marrow for a short period and can be collected from peripheral blood.

For this mobilization of hematopoietic stem cells, leukocyte stimulating growth factors (cytokines) and granulocyte stimulating factors are applied. Hematopoietic stem cells can be collected via a process called aphresis, which targets specific white blood cells. The procedure is much less invasive for donors and is similar in quality to procedure for bone marrow-harvested stem cells. An important, recent clinical application of hematopoietic stem cells is transplantation of allogenic bone marrow for the treatment of leukemia.