Early Taurine Administration Decreases the Levels of Receptor-Interacting Serine/Threonine Protein Kinase 1 in the Duchenne Mouse Model mdx.

Background/

Objectives

The progressive life-limiting disorder Duchenne muscular dystrophy (DMD) arises from the absence of dystrophin protein at the muscle cell membrane, which leads to progressive contraction-induced damage. Despite the advancements in molecular therapies aimed at reintroducing (partially functional) dystrophin in patients, a cure for DMD remains elusive. Taurine supplements have been proposed as a potential supportive treatment for DMD, based upon encouraging results in the mouse model mdx.

Methods

In a previous study, we observed improvements in skeletal muscle histology and a reduction in the expression of inflammatory markers after short-term treatment with 4.6 g taurine per kg body weight during the initial stages of the disease. In this follow-up study, we examined cell death and tissue restoration protein levels in mdx subjected to the same treatment regimen, utilizing proteome arrays, Western blotting, and immunofluorescence.

Results

We report that, while the levels of apoptotic and autophagic proteins remained constant, selective and significant decrease in receptor-interacting Serine/Threonine protein kinase 1 (RIP1) levels could be observed in taurine-treated mdx compared to untreated mdx. RIP1 was immunolocalized to muscle fibers, with faint homogeneous staining in age-matched healthy controls shifting to a heterogeneous staining pattern in mdx, the latter diminishing with taurine treatment.

Conclusions

Given its role as a molecular switch in cell fate decisions, the observed taurine-induced downregulation of RIP1 supports the potential beneficial effects of the osmolyte in mdx.