Exosomal miR-302b rejuvenates aging mice by reversing cell cycle arrest [scRNA-Seq]

Senescent cells (SnCs) are considered the driving force of aging; therefore, restoring the normal function of SnCs or reversing the senescence-associated secretory phenotype (SASP) may have anti-aging effects. Current anti-aging strategies include destroying, or reprogramming, SnCs and inhibiting SASP. However, significant challenges persist, such as the progressive loss of tissue function and risk of tumorigenesis. Herein, we report a Senoreviver strategy that breaks cell cycle arrest and reverses SASP simultaneously via human embryonic stem cell exosome (hESC-Exo)-mediated delivery of miR-302b. miRNA-seq analysis revealed that hESC-Exos enriches miR-302 family members. Ago2 CLIP-seq mapping revealed that miR-302b could repress the cell cycle inhibitors Cdkn1a and Ccng2, which collectively restored the proliferative capacity of SnCs and reversed SASP. Our study provides a Senoreviver strategy to rejuvenate SnCs in vitro and in vivo, rather than eliminate or reprogram them, thus holding great promise for maintaining tissue homeostasis, extending the health span, and countering age-related diseases. At the age of 20 months, mice were randomly divided into Aging-pbs (n = 30) and Aging-Exos (n = 30) groups and transferred to the Institute of Biophysics, Chinese Academy of Sciences, in an SPF-grade facility with individually ventilated cages. Mice in the Aging-Exos group received a weekly tail vein injection of hESC-Exos (2 × 1010 particles in 200 μL PBS), while those in the Aging-pbs group were administered 200 μL PBS via tail vein injection. The 30th month was selected as the test point. Three mice were chosen randomly from each of the two groups, and their skin and liver tissues were collected for single-cell sequencing.