Monday, October 14, 2019

Cosmic Longevity - Prerequisite for the Conquest of Space

technologyreview |  Izpisúa Belmonte believes epigenetic reprogramming may prove to be an “elixir of life” that will extend human life span significantly. Life expectancy has increased more than twofold in the developed world over the past two centuries. Thanks to childhood vaccines, seat belts, and so on, more people than ever reach natural old age. But there is a limit to how long anyone lives, which Izpisúa Belmonte says is because our bodies wear down through inevitable decay and deterioration. “Aging,” he writes, “is nothing other than molecular aberrations that occur at the cellular level.” It is, he says, a war with entropy that no individual has ever won.

But each generation brings new possibilities, as the epigenome gets reset during reproduction when a new embryo is formed. Cloning takes advantage of reprogramming, too: a calf cloned from an adult bull contains the same DNA as the parent, just refreshed. In both cases, the offspring is born without the accumulated “aberrations” that Izpisúa Belmonte refers to.

What Izpisúa Belmonte is proposing is to go one step better still, and reverse aging-related aberrations without having to create a new individual. Among these are changes to our epigenetic marks—chemical groups called histones and methylation marks, which wrap around a cell’s DNA and function as on/off switches for genes. The accumulation of these changes causes the cells to function less efficiently as we get older, and some scientists, Izpisúa Belmonte included, think they could be part of why we age in the first place. If so, then reversing these epigenetic changes through reprogramming may enable us to turn back aging itself.

Izpisúa Belmonte cautions that epigenetic tweaks won’t “make you live forever,” but they might delay your expiration date. As he sees it, there is no reason to think we cannot extend human life span by another 30 to 50 years, at least. “I think the kid that will be living to 130 is already with us,” Izpisúa Belmonte says. “He has already been born. I’m convinced.”