Your Organs Are Aging At Different Speeds

The Household Physician, 1905

Our bodies are a patchwork of different systems, and new analysis suggests aging effects each organ very differently. 

Different organs behave very differently, leaving some regularly renewed and some refreshed rarely. The skin and gut are constantly in flux, but the heart and brain are rarely renewed. These differences in behaviour and pressures mean each organ has to deal with different types of damage and risks, and aging develops in an equally varied manner. 

Organs are not all alike

Aging is still cloaked in mystery. We know the hallmarks, but we only have snapshots of a gigantic process, with many culprits. Researchers sought to unravel some of this mystery by comparing protein aging in two different organ systems - the brain and liver.

Aging is deterioration; a failure to deal with time's challenges. We know that across the body a number of similar genetic changes happen as we get older, but a recent study also found that physical levels of most proteins don't actually change. This led to some confusion, as while gene changes clearly occur, it wasn't clear what proteins were being changed. 

"Changes that occur in aging can be diverse and difficult to pin down, and looking simply at one parameter might result in not seeing the whole picture"

Scientists attempted to find out more by taking a state of the art integrated approach, analysing not just genomics or proteomics, but a whole range of connected factors. They looked beyond simply measuring what genes were active and what amount of protein was present, to checking things like how proteins were being modified. 

Research discovered 468 differences in protein abundance between young and old, and a set of 130 proteins that were modified differently with age. The powerful, integrated approach revealed more than any individual data set could. 

Mass analysis revealed interesting changes Credit: Brandon Toyama

These differences were organ specific

The liver is one of the only organs that can undergo significant regeneration, and liver tissue is constantly being turned over. This prevents damage building up, but slow-dividing tissue like the brain is far more vulnerable. It may be better shielded from harm, but any damage sticks around. 

This meant that the brain had a larger portion of proteins that had been modified by the aging process. These changes were mostly metabolic changes, affecting how the cells use and make energy. The brain changes involved aspects like memory formation and plasticity. The most interesting finding was that all of the changes revolved around protein turnover and formation. 

"Our study showed that organs have different aging mechanisms and that aging is largely driven by changes in protein production and turnover. Based on our findings, we would define aging as an organ-specific deterioration of the cellular proteome."

With more powerful analysis of further organs, we'll gain a much more accurate, and robust picture of the aging process as a whole. We can then hone in on patterns and get to work on fixing them. 

Read more at Medicalxpress