TABLE 1.
Studies reporting biological age reduction
| Study | Rejuvenation class | Species | Accession | Clock(s) applied | Reported biological age reduction |
|---|---|---|---|---|---|
| Horvath (2013) | Reprogramming (in vitro) | Human | Horvath multi‐tissue | iPSCs have a lower DNAm age than corresponding primary cells | |
| Petkovich et al. (2017) | Reprogramming (in vitro) | Mouse | GSE80672 | Petkovich blood | iPSCs have a lower DNAm age than corresponding primary fibroblasts |
| Olova et al. (2019) | Reprogramming (in vitro) | Human | GSE54848 |
Horvath multi‐tissue Weidner 99 CpG Skin & blood PhenoAge Hannum blood Weidner 3 CpG |
Steady decrease in epigenetic age during reprogramming of fibroblasts reported by 3 of the 5 applied epigenetic clocks (two other clocks did not show informative trajectories) |
| Meer et al. (2018) | Reprogramming (in vitro) | Mouse | GSE80672 |
Meer multi‐tissue Stubbs multi‐tissue Petkovich blood Wang liver |
iPSCs have remarkably lower DNAm age than primary fibroblasts as shown by 2 of 4 epigenetic clocks (minimal change by two other clocks) |
| Wang and Lemos (2019) | Reprogramming (in vitro) | Mouse | GSE80672 | Wang blood rDNA | iPSCs have a lower ribosomal DNAm age than primary fibroblasts |
| Fahy et al. (2019) | Thymus regeneration treatment (in vivo) | Human | NA |
Horvath multi‐tissue PhenoAge Hannum blood GrimAge |
A decrease in epigenetic age after 12 months of treatment (intended to regenerate the thymus) by four applied clocks |
| Sarkar et al. (2020) | Reprogramming (in vitro) | Human | GSE142439 | Horvath multi‐tissue | Transient reprogramming reverted the DNA methylation age of aged fibroblasts and endothelial cells |
| Lu et al. (2020) | Reprogramming (in vivo) | Mouse | PRJNA655981 | Wang blood rDNA | Lower rDNAm age of RGCs from axon‐injured retinas upon an OSK treatment |
| Horvath et al. (2020) (preprint) | Heterochronic transplantation (in vivo) | Rat | NA |
5 rat clocks (pan‐tissue, blood, liver, heart, brain) Human‐rat |
Lower epigenetic age after a plasma fraction treatment in four tissues |
| Gill et al. (2021) (preprint) | Reprogramming (in vitro) | Human | NA |
Horvath multi‐tissue Skin & blood Transcriptome |
Remarkable (~30 year) decrease in epigenetic age and transcriptomic age by maturation phase transient reprogramming of fibroblasts |
| Kerepesi et al. (2021) | Reprogramming (in vitro) | Mouse | GSE80672 | Multi‐tissue rDNA | iPSCs have a lower DNAm age than primary fibroblasts |
| Embryonic (in vivo) | Mouse |
Petkovich blood Stubbs multi‐tissue Meer multi‐tissue Thompson multi‐tissue Blood rDNA Multi‐tissue rDNA |
Epigenetic age of embryonic day 6.5/7.5 embryos is lower than in earlier stages of embryogenesis by all of applied clocks | ||
| Trapp et al. (2021) (preprint) | Embryonic (in vivo) | Mouse | GSE121690 | scAge | Profound epigenetic age decrease in single cells between embryonic days 4.5 and 7.5 |
Abbreviations: iPSC, induced pluripotent stem cell; NA, not available; OSK, Oct4/Sox2/Klf4; rDNA, ribosomal DNA; RGC, retinal ganglion cell.