Age-related inflammation triggers skeletal stem/progenitor cell dysfunction.

Aging is associated with impaired tissue regeneration. Stem cell number and function have been identified as potential culprits. We first demonstrate a direct correlation between stem cell number and time to bone fracture union in a human patient cohort.

Ecto-5'-nucleotidase (CD73) regulates bone formation and remodeling during intramembranous bone repair in aging mice.

Ecto-5'-nucleotidase (CD73) generates adenosine, an osteoblast activator and key regulator of skeletal growth. It is unknown, however, if CD73 regulates osteogenic differentiation during fracture healing in adulthood, and in particular how CD73 activity regulates intramembranous bone repair in the elderly. Monocortical tibial defects were created in 46-52-week-old wild type (WT) and CD73 knock-out mice (CD73) mice.