Aggrephagy in Hematopoietic Stem Cell Aging

Autophagy is the name given to a complex, varied set of processes that tag and recycle broken or excess proteins and structures in the cell. The destination for materials to be recycled is the lysosome, a membrane-wrapped collection of enzymes capable of breaking down near all of the proteins and other molecules a cell is likely to encounter. How materials are selected and how exactly they make their way to the lysosome varies considerably. Alongside autophagy, the ubiquitin-proteasome system is another way for cells to identify problem proteins, such as those that misfold into toxic configurations, and then break them down into their component parts for reuse. In short-lived species, improvement in autophagy or improvement in proteasomal degradation produces a slowing of aging. More effective cellular housekeeping implies a lower burden of damage inside cells, fewer downstream issues resulting from that damage, and thus better cell and tissue function. Today's open access paper is one of many examples of researchers probing the complexities of cell maintenance, asking why some stem cell populations appear to undertake far too little proteasomal activity in order to clear out broken proteins. The authors found that these cells instead rely on a form of autophagy targeting the protein aggregates that can form as a result of misfolding. All of these housekeeping processes decline in effectiveness with advancing age, and it is possible that ways to at least modestl...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs