Why stem/progenitor cells lose their regenerative potential

Figure 4 Changes in chromatin related to stem cell aging. In hematopoietic stem cells, satellite cells, and other types of stem cells, changes in the structure and makeup of chromatin during aging have been studied. Differences in chromatin-modifying enzyme levels and distribution (blue oval shapes), histone modifications (green flag, activating; red flag, repressive), and DNA methylation patterns (pink star) are among these shifts. Regional loss of transcriptional silencing altered cell fate decisions, reduced activity, and cellular senescence are all consequences of these changes.