Thyroid hormones and skeletal muscle - new insights and potential implications

[helvella]

We have seen the enzyme deiodinase 2 (DIO2) and its related genes being pointed at as a possible cause of some thyroid hormone issues. This paper goes on to point a finger at the activity of deiodinase 3 (DIO3). Clearly, the amount of T3 present will depend on the balance between DIO2 converting T4 into T3, and that of DIO3 converting T3 to T2.

Nat Rev Endocrinol. 2013 Dec 10. doi: 10.1038/nrendo.2013.238. [Epub ahead of print]

Thyroid hormones and skeletal muscle-new insights and potential implications.

Salvatore D, Simonides WS, Dentice M, Zavacki AM, Larsen PR.

Source

Department of Clinical Medicine and Surgery, University of Naples 'Federico II', Building 1, 1st floor, Via Pansini 5, 80131 Naples, Italy.

Abstract

Thyroid hormone signalling regulates crucial biological functions, including energy expenditure, thermogenesis, development and growth. The skeletal muscle is a major target of thyroid hormone signalling. The type 2 and 3 iodothyronine deiodinases (DIO2 and DIO3, respectively) have been identified in skeletal muscle. DIO2 expression is tightly regulated and catalyses outer-ring monodeiodination of the secreted prohormone tetraiodothyronine (T4) to generate the active hormone tri-iodothyronine (T3). T3 can remain in the myocyte to signal through nuclear receptors or exit the cell to mix with the extracellular pool. By contrast, DIO3 inactivates T3 through removal of an inner-ring iodine. Regulation of the expression and activity of deiodinases constitutes a cell-autonomous, pre-receptor mechanism for controlling the intracellular concentration of T3. This local control of T3 activity is crucial during the various phases of myogenesis. Here, we review the roles of T3 in skeletal muscle development and homeostasis, with a focus on the emerging local deiodinase-mediated control of T3 signalling. Moreover, we discuss these novel findings in the context of both muscle homeostasis and pathology, and examine how skeletal muscle deiodinase activity might be therapeutically harnessed to improve satellite-cell-mediated muscle repair in patients with skeletal muscle disorders, muscle atrophy or injury.

PMID: 24322650 [PubMed - as supplied by publisher]

ncbi.nlm.nih.gov/pubmed/243...

Rod

Image is thumbnails of the illustrations from the article.

[PinkNinja]

Are you bored or just catching up on your reading?

Another interesting article. Maybe this is part of the reason why hypothyroid patients experience muscle pain and stiffness and hyperthyroid patients experience muscle weakening (and sometimes pain/stiffness).

The potential for treatments following on from this research is also interesting. Amazing what they can do these days, even if they can't get all us thyroid patients feeling well again

Carolyn x

[helvella Administrator Thyroid UK in reply to PinkNinja]

I tend to glance through alerts of papers - selecting the odd one here or there for further thought. Occasionally one demands immediate posting for some reason or another. But a lot remain in open browser tabs until I look again and decide whether or not to post.

It really does just happen to be that I had a lot of worthwhile papers to post about! And there is is very little else happening here at the moment.

The logjam between research and clinical practice is worsening day by day. Even though I am having a post-fest now, it is a tiny fraction of what has been published. How much of that research shows any likelihood of helping those here?

[Hidden in reply to helvella]

I was also thinking you're very busy tonight Rod!

Thanks for the posts - several are very relevant to me anyway, and I suspect very relevant to other sufferers too.- let's just hope some medical practitioners read them and take note. J

[PinkNinja in reply to helvella]

Unfortunately the NHS seems to ignore a lot of research that doesn't suit them...

Thanks for all the posts. I always enjoy reading them

(I'm not getting any notifications or I would have responded sooner. This site seems to have brain fog these days!)

[helvella Administrator Thyroid UK in reply to PinkNinja]

No - nor am I, of any replies.

[nightingale-56]

Thanks for posting Rod. I am so convinced I need a bit of T3. Janet.

[Marz]

....could this be of any use to Fibro sufferers ? Thank you Rod for your post.