A Gentler Approach to Transplanting Young Hematopoietic Stem Cells into Old Mice Modestly Extends Life Span

Stem cell populations become damaged and dysfunctional with age. Some of this is issues with the stem cells themselves, and some of this results from problem with the signaling environment and function of the stem cell niche. Which of these factors is more important likely varies by stem cell population. Among the best studied of stem cell types, the evidence suggests that muscle stem cells remain capable in old age, but become ever more quiescent, while hematopoietic stem cells become damaged and dysfunctional, unable to perform. Hematopoietic stem cells reside in the bone marrow and are responsible for generating blood and immune cells. Altered and reduced hematopoiesis is an important aspect of immune system decline with age, and thus providing functional replacement cells to older individuals may prove to be a useful form of rejuvenation therapy. Unfortunately, the introduction of new hematopoietic stem cells at present requires removal of the existing population in order to make space in the stem cell niches of the bone marrow. The options for replacement are somewhat blunt and limited, deriving from the bone marrow transplant field. The standard approach is chemotherapy, which is quite unpleasant to experience, and further comes accompanied by a non-trivial risk of death or failure to adequately reconstitute the immune system following transplantation. That risk profile is considerably worse in older patients, and thus this sort of therapy is largely restricted t...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs