Study proves ‘muscle memory’ exists at a DNA level

Authored by keele.ac.uk and submitted by mvea

Study proves ‘muscle memory’ exists at a DNA level

A study led by researchers at Keele University has shown for the first time that human muscles possess a ‘memory’ of earlier growth - at the DNA level.

Periods of skeletal muscle growth are ‘remembered’ by the genes in the muscle, helping them to grow larger later in life.

‌The research, published in Scientific Reports - Nature, could have far-reaching implications for athletes caught using performance-enhancing muscle building drugs - as the drugs could be creating long-lasting changes, making short-term bans inadequate.

Using the latest genome wide techniques, the researchers from Keele, along with the Universities of Liverpool John Moores, Northumbria and Manchester Metropolitan, studied over 850,000 sites on human DNA and discovered the genes 'marked' or 'unmarked' with special chemical 'tags' when muscle grows following exercise, then returns back to normal and then grows again following exercise in later life.

Known as epigenetic modifications, these ‘markers’ or ‘tags’ tell the gene whether it should be active or inactive, providing instructions to the gene to turn on or off without changing the DNA itself.

Dr Adam Sharples, the senior and corresponding author of the study and Senior Lecturer in Cell and Molecular Muscle Physiology at Keele University and his PhD student Mr Robert Seaborne explained:

“In this study, we’ve demonstrated the genes in muscle become more untagged with this epigenetic information when it grows following exercise in earlier life, importantly these genes remain untagged even when we lose muscle again, but this untagging helps ‘switch’ the gene on to a greater extent and is associated with greater muscle growth in response to exercise in later life - demonstrating an epigenetic memory of earlier life muscle growth!”

The research has important implications in how athletes train, recover from injury, and also has potentially far-reaching consequences for athletes caught cheating.

“If an athlete’s muscle grows, and then they get injured and lose some muscle, it may help their later recovery if we know the genes responsible for muscle 'memory’. Further research will be important to understand how different exercise programmes can help activate these muscle memory genes.”

“If an elite athlete takes performance-enhancing drugs to put on muscle bulk, their muscle may retain a memory of this prior muscle growth. If the athlete is caught and given a ban - it may be the case that short bans are not adequate, as they may continue to be at an advantage over their competitors because they have taken drugs earlier in life, despite not taking drugs anymore. More research using drugs to build muscle, rather than exercise used in the present study, is required to confirm this.”

GeneticsGuy on January 31st, 2018 at 17:16 UTC »

Just to comment, in case anyone is wondering... this does not actually code changes into the actual DNA strand. What this has to do with is epigenetics, which is essentially the process of how the DNA gets packaged up within a cell.

You see, DNA protein expression and regulation is controlled in various ways. One of the ways is how the DNA packages itself from cell to cell. If it is wound up very tightly and packaged in certain ways, then certain genes are hidden from the collision that would activate transcription of those genes. Some packaging loosens up some areas of the DNA and exposes them to those collisions which can create activation events which lead downstream to protein production.

Well, basically the DNA is being imprinted with chemical methylations that cause it to package up in certain ways. This is the very essence of epigenetics. It is not the code of the DNA carrying information anymore, but these chemical markers that cause the DNA to fold and package in a specific way are carried on after division.

This study is showing how certain events earlier in life landed those epigenetic DNA methylations (plus other epigenetic modifications) and they have strong downstream effects, even years later (Edit: Correction, 22 weeks later in this study), on gene expression related to muscle growth.

dkysh on January 31st, 2018 at 16:43 UTC »

I wonder if this affects also the heart and cardio exercise.

mvea on January 31st, 2018 at 10:53 UTC »

The title of the post is cut and paste from linked academic press release here:

Study proves ‘muscle memory’ exists at a DNA level

A study led by researchers at Keele University has shown for the first time that human muscles possess a ‘memory’ of earlier growth - at the DNA level.

Periods of skeletal muscle growth are ‘remembered’ by the genes in the muscle, helping them to grow larger later in life.

Journal reference:

Human Skeletal Muscle Possesses an Epigenetic Memory of Hypertrophy

Robert A. Seaborne, Juliette Strauss, Matthew Cocks, Sam Shepherd, Thomas D. O’Brien, Ken A. van Someren, Phillip G. Bell, Christopher Murgatroyd, James P. Morton, Claire E. Stewart & Adam P. Sharples

Scientific Reportsvolume 8, Article number: 1898 (2018)

doi:10.1038/s41598-018-20287-3

Link: https://www.nature.com/articles/s41598-018-20287-3

Published online: 30 January 2018

Abstract

It is unknown if adult human skeletal muscle has an epigenetic memory of earlier encounters with growth. We report, for the first time in humans, genome-wide DNA methylation (850,000 CpGs) and gene expression analysis after muscle hypertrophy (loading), return of muscle mass to baseline (unloading), followed by later hypertrophy (reloading). We discovered increased frequency of hypomethylation across the genome after reloading (18,816 CpGs) versus earlier loading (9,153 CpG sites). We also identified AXIN1, GRIK2, CAMK4, TRAF1 as hypomethylated genes with enhanced expression after loading that maintained their hypomethylated status even during unloading where muscle mass returned to control levels, indicating a memory of these genes methylation signatures following earlier hypertrophy. Further, UBR5, RPL35a, HEG1, PLA2G16, SETD3 displayed hypomethylation and enhanced gene expression following loading, and demonstrated the largest increases in hypomethylation, gene expression and muscle mass after later reloading, indicating an epigenetic memory in these genes. Finally, genes; GRIK2, TRAF1, BICC1, STAG1 were epigenetically sensitive to acute exercise demonstrating hypomethylation after a single bout of resistance exercise that was maintained 22 weeks later with the largest increase in gene expression and muscle mass after reloading. Overall, we identify an important epigenetic role for a number of largely unstudied genes in muscle hypertrophy/memory.