Age-Associated Characteristics of Murine Hematopoietic Stem Cells

The most profound immunologic effect of stem cell aging in mice and humans is a reduced ability to generate lymphocytes and an increased myeloid potential.

“From an immunologic perspective, the most profound effect of stem cell aging in both mice (11,18) and humans (17) is a decreased capacity to produce lymphocytes and an increase in myeloid potential.”

Aged mice have an overall larger HSC pool.

“in aged mice that display an overall increase in HSC pool size”

The functional heterogeneity of the HSC population rises with age.

“the functional heterogeneity of the HSC population increases with age.”

Individual HSCs in aged mice behave very differently from one another.

“individual HSCs behave very differently.”

Mice whose blood cell production comes from even a single stem cell are not necessarily prone to leukemia.

“mice in which blood cell production is derived from even a single stem cell, are not necessarily prone to develop leukemia.”

HSCs reside largely in a dormant state, with >90% in quiescent G0 phase in both young and old mice, and enter cycle infrequently throughout adult life.

“HSCs reside largely in a state of dormancy, with >90% in the quiescent G0 phase of the cell cycle in both young and old mice (Figure S5) (Rossi et al., 2007b; Sudo et al., 2000), entering into cycle infrequently throughout the adult lifespan (Cheshier et al., 1999; Foudi et al., 2008; Wilson et al., 2008).”

As humans age, they typically experience an increase in total phenotypic HSC numbers as the cell pool grows with time.

“As humans age, they typically experience an increase in total phenotypic HSC numbers as the cell pool grows with time (de Haan and Van Zant, 1999; Pang et al., 2011; Sudo et al., 2000).”