The role of PGC-1beta pinpointed in muscle performance
Dec. 17, 2015
The PGC-1α and PGC-1β transcriptional co-regulators are known to be involved in energy metabolism. While PC-1α is already well studied, only few data on the pathophysiological role of PGC-1β are available. In a new study published on December 17th 2015 in the journal Nature communications, the researchers of Daniel Metzger’s team were able to inactivate specifically PGC-1β in muscle fibers of adult mice. The results obtained in collaboration with the teams of Bernard Geny and Arnaud Ferry, show that this co-regulator is essential for optimal mitochondrial activity in the cells.
Mitochondria and muscular activities
Muscles need a lot of energy to perform their functions. The major part of this energy is produced in specialized cell organelles, mitochondria. These are present in large number in muscle cells and use oxygen to transform energy contained in the sugar and fat in ATP. This molecule is essential to generate muscle contraction.
The PGC-1α and PGC-1β co-regulators are involved in mitochondrial biogenesis and energy metabolism. In some cells the action of one compensate the loss or the decrease of the other. While the pathophysiological roles of PGC-1α in the muscle are fairly well defined, those of PGC-1β remain largely misunderstood.
PGC-1β’s role in muscle
Daniel Metzger’s team managed to inactivate selectively PGC-1β in muscles fibers of adult mice avoiding compensation by PGC-1α that could be put in place during muscle formation. The study conducted in collaboration with the teams of Bernard Geny and Arnaud Ferry shows that PGC-1β coordinates the expression of numerous proteins involved in the structure and function of mitochondria. It also participates in their detoxification, effectively eliminating the reactive oxygen derivatives generated. Therefore, in the absence of PGC-1β, although the number of mitochondria remains unchanged, they have structural and functional abnormalities which decrease their performances.
PGC-1β is thus a key factor for optimal muscle activity. However, the levels of this co-regulator decrease with age in this tissue, inducing muscle weakness. As its expression can be induced by polyphenols, present in red wine for instance, these results open new perspectives to prevent and delay muscle impairment caused by mitochondrial dysfunction or aging.