Cellular Reprogramming, and the Goal of Separating Dedifferentiation from Epigenetic Rejuvenation

Rejuvenation takes place very early in embryonic development. The germline cells that go into the creation of an embryo are well protected and maintained in comparison to the average somatic cell in the adult body. Nonetheless, there is an accumulation of age-related epigenetic changes and molecular damage. Cells purge themselves of as much of this change and damage as possible, in order to ensure that the young are born with young somatic cells and tissues. This is primarily a resetting of epigenetic controls over gene expression, decorations on the structure of the genome that control shape and access to specific genes by the molecular machinery responsible for producing proteins from genetic blueprints. A cell is a state machine, largely governed in operation by the matter of which proteins are produced, and in what quantities. Not completely governed: some damage, such as mutations to nuclear DNA, is irreversible. Some molecular waste cannot be managed even by cells in a youthful epigenetic state, and will degrade normal function. In a collection of replicating cells, that waste can be diluted via cell division, or even passed off entirely to a sacrificial daughter cell in a process of asymmetric division. So long as no one cell or small number of cells are vital, even serious mutation can be evaded by replication, provided that mutated cells are rejected. This is how single celled life, such as bacteria, can continue indefinitely. Further, a few lower organisms, s...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs