Regenerative MedicineHow Aging Hijacks Cell Signals in Blood Stem Cells — and How to Reverse It
Extracellular vesicles (EVs) are tiny membrane-wrapped packets that carry proteins, RNA, and lipids between cells, coordinating how blood stem cells behave in the bone marrow. As we age, the cells lining that niche — including mesenchymal stromal cells and osteoblasts — release increasingly dysfunctional EVs. These aging EVs carry altered microRNA profiles and fewer protective antioxidants, which spreads cellular senescence, disrupts stem cell regulation, and shifts blood production toward inflammatory myeloid cells over immune-protective lymphoid cells. This myeloid bias underlies rising risks of anemia, immune decline, and blood cancers in older adults. Critically, surface proteins on EVs determine which cells they target, making EV signaling highly selective. Encouragingly, EVs from young or pluripotent stem cells can reverse these aging effects, pointing toward EV-based therapies and diagnostics as realistic tools for combating age-related blood system dysfunction.
