In today’s #apaperaday, Prof. Aartsma-Rus reads and comments on the paper titled: Muscle Pathology in Dystrophic Rats and Zebrafish Is Unresponsive to Taurine Treatment, Compared to the mdx Mouse Model for Duchenne Muscular Dystrophy
Today’s pick is from the journal metabolites by Terrill et al on the unresponsiveness of taurine treatment of muscle pathology in fish and rats lacking dystrophin. Doi: 10.3390/metabo13020232.
Duchenne pathology is characterized by chronic inflammation & oxidative stress. Taurine is an amino acid with antioxidant and anti-inflammatory properties. In the mdx mouse model there is a deficiency of taurine in muscles and supplementing with taurine had beneficial effects.
Here authors tested effects of taurine supplementation in a rat and fish model of Duchenne. First rat: rats without dystrophin had reduced strength & function but taurine treatment did not improve things. No improvement found on histology, inflammatory status and oxidative stress.
Unexpectedly rats without dystrophin had higher taurine levels in blood and muscle than wild types. In zebrafish without dystrophin function was worse than for wild types, but also here taurine supplementation did not improve things & taurine levels were higher in muscles. Authors then checked taurine serum levels for Duchenne patients showing now difference in young patients and a mild decrease in older, non ambulant patients. Note older individuals have higher taurine levels to begin with.
The lower serum levels in Duchenne can also reflect a lower muscle mass rather than a deficiency in the muscle patients still have. Authors outline ideally taurine levels are measured over time in Duchenne muscles but this is challenging given the invasiveness of muscle biopsies.
The conclusion is that taurine probably had therapeutic effects in the mdx mouse but not in rat and fish and likely not in humans. Kudos to the authors for sharing their new findings even though they were not what they and the field were hoping for. Sharing these results avoids unnecessary work! So there is an obligation to share even if you do not like your results. Great that authors do this here. Note that the hypothesis made sense, and they managed to get funding to test it, but often nature is more complex than assumed.