The hematopoietic system in the context of regenerative medicine

Abstract

Hematopoietic stem cells (HSC) represent the prototype stem cell within the body. Since their discovery, HSC have been the focus of intensive research, and have proven invaluable clinically to restore hematopoiesis following inadvertent radiation exposure and following radio/chemotherapy to eliminate hematologic tumors. While they were originally discovered in the bone marrow, HSC can also be isolated from umbilical cord blood and can be “mobilized” peripheral blood, making them readily available in relatively large quantities. While their ability to repopulate the entire hematopoietic system would already guarantee HSC a valuable place in regenerative medicine, the finding that hematopoietic chimerism can induce immunological tolerance to solid organs and correct autoimmune diseases has dramatically broadened their clinical utility. The demonstration that these cells, through a variety of mechanisms, can also promote repair/regeneration of non-hematopoietic tissues as diverse as liver, heart, and brain has further increased their clinical value. The goal of this review is to provide the reader with a brief glimpse into the remarkable potential HSC possess, and to highlight their tremendous value as therapeutics in regenerative medicine.

Chromosomal Abnormalities in Embryonic and Somatic Stem Cells

“…In vitro, SSCs display greater plasticity, showing higher differentiation potential than in vivo [Jiang et al, 2002;Franco Lambert et al, 2009]. Among SSCs, human mesenchymal stromal, hematopoietic and neural SCs already find an application in the clinic [Bajada et al, 2008;Thomsen et al, 2014;Porada et al, 2015].…”

Hematopoietic Stem Cells in Regenerative Medicine: Astray or on the Path?

“…For example, pre-clinical studies suggested that HSCs from bone marrow and cord blood should have the ability to repair the infarcted heart, improving function and survival in a murine systems. Immediately, this observation triggered the launch not only of pre-clinical but, surprisingly, also of numerous clinical studies [63,64]. Based on these claims, a general debate emerged whether somatic stem cells including HSCs could have a wider, possibly even unlimited differentiation potential similar to pluripotent embryonic stem cells [65].…”

The contribution of bone marrow-derived cells to the human adipocyte pool

“…It is currently a matter of debate whether haematopoietic stem cells can develop into cells outside the haematopoietic lineage 32,[39][40][41][42][43][44][45] and most investigators suggest that haematopoietic stem cells cannot cross lineage boundaries. 42 In accordance with this, bulk preparations of human fat cells from BM-transplanted subjects expressed no detectable amounts of haematopoietic markers.…”