Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse

Spurney CF, Cha HJ, Sali A, Pandey GS, Pistilli E, Guerron AD, Gordish-Dressman H, Hoffman EP, Nagaraju K · PLoS One

Treated mdx mice had significantly more regenerating skeletal muscle fibres (11.6 ± 13.5 per field against 2.6 ± 1.1, p = 0.03), but grip strength, rotarod performance, systolic cardiac function, serum creatine kinase and skeletal and cardiac fibrosis were all unchanged — a histological effect with no functional payoff over six months.

Population

Exercised female mdx (dystrophin-deficient) mice and wild-type controls, 8 to 10 weeks old at the start

Intervention

150 µg thymosin β4 intraperitoneally twice weekly for six months

Comparator

Buffer-injected mdx and wild-type mice

Limitations

One disease model; the dissociation between a tissue marker and function is the point, and it is a caution for reading histology-only healing results. Histology was scored blind by two observers, and the fibre count's standard deviation exceeds its mean because regeneration is patchy. Tβ4 supplied by RegeneRx; NIH, Department of Defense and muscular dystrophy charity funding, no competing interests.