Exosomal miR-302b rejuvenates aging mice by reversing the proliferative arrest of senescent cells

Cellular senescence, a hallmark of aging, involves a stable exit from the cell cycle. Senescent cells (SnCs) are closely associated with aging and aging-related disorders, making them potential targets for anti-aging interventions. In this study, we demonstrated that human embryonic stem cell-derived exosomes (hESC-Exos) reversed senescence by restoring the proliferative capacity of SnCs in vitro. In aging mice, hESC-Exos treatment remodeled the proliferative landscape of SnCs, leading to rejuvenation, as evidenced by extended lifespan, improved physical performance, and reduced aging markers. Ago2 Clip-seq analysis identified miR-302b enriched in hESC-Exos that specifically targeted the cell cycle inhibitors Cdkn1a and Ccng2. Furthermore, miR-302b treatment reversed the proliferative arrest of SnCs in vivo, resulting in rejuvenation without safety concerns over a 24-month observation period. These findings demonstrate that exosomal miR-302b has the potential to reverse cellular senescence, offering a promising approach to mitigate senescence-related pathologies and aging.