Reprogramming to recover youthful epigenetic information and restore vision.
Level 5 - mechanism / opinion, no new human data
Preclinical animal and bench research with no human clinical data
PubMed 33268865 · doi:10.1038/s41586-020-2975-4
What was done
Researchers evaluated whether partial epigenetic reprogramming could restore youthful cellular state and function in the central nervous system. Using the mouse eye as a model, they ectopically expressed Oct4, Sox2, and Klf4 (OSK) in mouse retinal ganglion cells. They evaluated changes in DNA methylation patterns and transcriptomes, axon regeneration following injury, and visual function in both a mouse model of glaucoma and naturally aged mice, testing the necessity of DNA demethylases TET1 and TET2.
What was found
Ectopic OSK expression restored youthful DNA methylation patterns and transcriptomes in retinal ganglion cells, promoted post-injury axon regeneration, and reversed vision loss in glaucoma-model mice and aged mice. Axon regeneration and functional recovery were dependent on TET1 and TET2. The abstract reports no numerical values, effect sizes, or sample sizes.
Why it matters
This study provides proof-of-concept in mammals that aged central nervous system tissues retain youthful epigenetic information that can be accessed via targeted transcription factor expression to drive tissue regeneration and functional recovery in vivo.
Limits
The study is restricted entirely to mouse models and in vitro/ex vivo assays, so translatability to human retinal disease or aging is unknown. The abstract does not provide quantitative metrics, sample sizes, durability of the effect, or assessments of long-term oncogenic or off-target risks associated with in vivo reprogramming factors.
Cited by
- supports Introducing three specific genes into the optic nerve and activating them for 6 to 8 weeks resets the cellular age of the nerves by approximately 75%.
- context In David Sinclair's laboratory, reversing the epigenetic age of cancer cells causes a majority of them to die and tumors to shrink in animal models.
- context Researchers have successfully cured total blindness in monkeys, restoring their sight within six weeks.