Victoria Gomes in Nautilus:
Part of Vittorio Sebastiano’s job is to babysit a few million stem cells. The research professor of reproductive biology at Stanford University keeps the cells warm and moist deep inside the Lorry I. Lokey Stem Cell Research Building, one of the nation’s largest stem cell facilities. He’s joined there by an army of researchers, each with their own goals. His own research program is nothing if not ambitious: He wants to reverse aging in humans. Stem cells are the Gary Oldman of cell types. They can reprogram themselves to carry out the function of virtually any other type of cell, and play a vital role in early development. This functional reprogramming is usually accompanied by an age reset, down to zero. Sebastiano figures that if he can separate these different kinds of reprogramming, he can open up a whole new kind of aging therapy. Nautilus caught up with him last month.
…Are germ cells immune to aging?
Yes and no. They definitely do age, but not to the same extent as other cell types. In males, spermatogenesis continues all the way from puberty to old life. If you take a 90-year-old man, there are still germ cells and spermatogonial stem cells. They do age, because it’s clear that the sperm of an older man is different from the sperm of a younger man, but they do not age as heavily as other cells. This is fascinating because we do not understand the process. Female cells do age, and the consensus is that there are no germ stem cells in the ovary so these cells lack a molecular program to stay young. But once you put together an egg and a sperm, then there is an aging erasure mechanism, which is embryonic-specific, that we also do not understand.