Is the sports hormone irisin the savior we are all waiting for?

Irisin is a so-called peptide that is released by muscle cells in humans after physical activity, among other things.
Now the PNAS has that Proceedings of the National Academy of Science, published the results of an experimental study. In this experimental study, which was carried out on mice, not only was an accelerated breakdown of alpha synuclein observed, but the spread of a Parkinson's-like disease was also reduced.

The effect, the researchers suspect, is that IRISIN is intended to promote the formation of new synapses in the hippocampus. This would also explain, among other things, why physical activity has such a beneficial effect on cognitive abilities.

And above all, it would explain why exercise has such a positive effect on Parkinson's, not only on cognitive abilities but on almost all motor skills, on the sense of balance and also on the gait pattern.

How did you go about this study?

Mice have been injected with a variant of Alf-synuclein. The variant involved a preformed fibril that behaved like a prion in the brain. This was done because it has been suggested that Parkinson's can spread through the brain in a similar way to how prions do. From this it could also be deduced why the disease progresses and why dementia can also develop in later phases.

And indeed, after the injection, the mice contracted a disease similar to Parkinson's. Crucially, it was possible to prevent the progression of the disease through gene therapy. You simply put a copy of the IRISIN gene in the liver, which then prompted the mice to produce more IRISIN, which also has the added benefit of being able to cross the blood-brain barrier. In the further investigations it was then proven that IRISIN promotes the breakdown of the prions in the nerve cells and thus the further accumulation of deposits could be prevented.

The same effect could not only be demonstrated in mice, but was also observed in the laboratory on cultures of brain cells.

Of course, it is still unclear at this point to what extent the results are relevant for patients with Parkinson's disease. But the fact that the researchers have already secured a patent for use in humans suggests that the subjectively positive expectations are high.

But as always, careful preclinical and clinical studies have to be carried out before approval and it will be several years before the assumption that an approved one turns out to be true Therapy will have arisen from it.

The result of the study is no more, but above all no less than another chance to get Parkinson's disease under control in the future.

Didn't we already learn as children that kiss a lot of frogs before you find a prince?

Jurgen Zender, in September 2022

Source: Proceedings of the National Academy of Science, PNAS 2022; DOI: 10.1073/pnas.2204835119