By using the expression of the protein BMI1 as a marker of the regenerative capacity of progenitor cells after tissue damage, the researchers “have observed that BMI1 levels decrease throughout the life of the mice. In parallel, there is a quantitative decrease in cardiac stem cells related to age. While stem cells in an adolescent mouse are widely distributed throughout the heart, in adult mice they are preferably located near the perivascular areas. "
In addition, researchers have found that both the type of cells to which progenitors differentiate and the levels of BMI1 expression are influenced by small molecules with oxidation capacity - the so-called reactive oxygen species (ROS). The relevance of this finding "is that we have found a correlation between aging and the levels of these reactive oxygen species in the myocardium, also correlated with the distribution of heart stem cells." The endothelial network of the adult heart maintains regions with low levels of these molecules where progenitor cells are preferentially housed. These results would confirm that oxidative stress is a limiting factor in cardiac regeneration capacity. "
More information:
Age-related oxidative stress confines damage-responsive Bmi1+ cells to perivascular regions in the murine adult heart. Herrero D, Cañón S, Albericio G, Carmona RM, Aguilar S, Mañes S, Bernad A. Redox Biol. 2019 Mar 4;22:101156. doi: 10.1016/j.redox.2019.101156.