Talk:Homing (hematopoietic)

Journal Refernces
I have included references to certain journals. Much of the content of the pages can be included (after modification) to enrich the contents of this page. User participation is encouraged.  D ip ta ns hu Talk 04:32, 23 December 2012 (UTC)

Source contents free or copyrighted
I had included text directly from the following source: Since the Full text of contents are available publicly, I have assumed it to be free. I have not rewritten it. Seeking insights.  D ip ta ns hu Talk 11:18, 11 May 2013 (UTC)


 * Unfortunately, it's copyrighted and should not be copied word-for-word onto Wikipedia; see the permissions page, but in general, you can assume that anything not licensed CC-by-SA or public domain is unsuitable for copying and pasting into Wikipedia. I can't really understand it so wouldn't know where to start with rewriting it, however. Graham 87 12:00, 11 May 2013 (UTC)
 * I've removed that section, for now, as a copyright violation. Graham 87 12:09, 11 May 2013 (UTC)
 * I would try to add it back only after I can rewrite it. Thanks for your cooperation.  D ip ta ns hu Talk 14:46, 11 May 2013 (UTC)

Mechanism
Several components of the essential process of stem cell homing have now been characterized. Cell adhesion molecules and their ligands, extracellular matrix components, chemokines, and specialized bone marrow niches all participate in the precise regulation of this process.

Migration of hematopoietic stem cells through the blood, across the endothelial vasculature to different organs and to their bone marrow niches, requires active navigation, a process termed homing. Homing is a rapid process and is the first and essential step in clinical stem cell transplantation. Similarly, homing is required for seeding of the fetal bone marrow by hematopoietic progenitors during development. Homing has physiological roles in adult bone marrow homeostasis, which are amplified during stress-induced recruitment of leukocytes from the bone marrow reservoir and during stem cell mobilization, as part of host defense and repair. Homing is thought to be a coordinated, multistep process, which involves signaling by stromal-derived factor 1 (SDF-1) and stem cell factor (SCF), activation of lymphocyte function–associated antigen 1 (LFA-1), very late antigen 4/5 (VLA-4/5) and CD44, cytoskeleton rearrangement, membrane type 1 (MT1)–matrix metalloproteinase (MMP) activation and secretion of MMP2/9. Rolling and firm adhesion of progenitors to endothelial cells in small marrow sinusoids under blood flow is followed by trans-endothelial migration across the physical endothelium/extracellular matrix (ECM) barrier. Stem cells finalize their homing uniquely, by selective access and anchorage to their specialized niches in the extravascular space of the endosteum region and in periarterial sites. This review is focused on mechanisms and key regulators of human stem cell homing to the bone marrow in experimental animal models and clinical transplantation protocols.