Interesting read. Most important parts summarized below.
Lead study author Yuancheng Lu, research fellow in genetics at HMS and a former PhD student in Sinclair’s lab, developed a gene therapy that could safely reverse the age of cells in a living animal.
Lu’s work builds on the Nobel Prize-winning discovery of Shinya Yamanaka, who identified the four transcription factors, Oct4, Sox2, Klf4 and c-Myc, that could erase epigenetics markers on cells and return these cells to their primitive embryonic state from which they can develop into any other type of cell.
Subsequent studies, however, showed two important setbacks. First, when used in adult mice, the four Yamanaka factors could also induce tumor growth, rendering the approach unsafe. Second, the factors could reset the cellular state to the most primitive cell state, thus completely erasing a cell’s identity.
Lu and colleagues circumvented these hurdles by slightly modifying the approach. They dropped the gene c-Myc and delivered only the remaining three Yamanaka genes, Oct4, Sox2 and Klf4. The modified approach successfully reversed cellular aging without fueling tumor growth or losing their identity.
The treatment resulted in a two-fold increase in the number of surviving retinal ganglion cells after the injury and a five-fold increase in nerve regrowth.
“At the beginning of this project, many of our colleagues said our approach would fail or would be too dangerous to ever be used,” said Lu. “Our results suggest this method is safe and could potentially revolutionize the treatment of the eye and many other organs affected by aging.”
Just in general what is wrong with older cells behaving young again?
I thought of an analogy of working on an old car. If you change the wheels of an old vehicle that has engine problems, putting brand new tires and rims won't make it run any better. Thus, if we end up repairing the cells of the eyes leading them to function like new again, perhaps all the blood vessels and neurons that lead to the eye are old and inefficient too. Hence, the new cells in the eye won't get the nutrients it needs to sustain its updated physiology.