Comparing effects of inhibition of activin receptor type IIB (ActRIIB), myostatin (GDF8) and/or activinA in mouse muscle. Comparing effects of inhibition of activin receptor type IIB (ActRIIB), myostatin (GDF8) and/or activinA in mouse muscle

This study was to compare the gene expression of our anti-GDF8 (i.e. anti-myostatin) and anti-activin A antibody combination to that of the activin receptor type IIB (ActRIIB.hFc) trap in SCID mice. The study was conducted in tibialis anterior muscle that is a common muscle type for the hypertrophy study. The combination treatment produces very similar muscle growth in tibialis muscle as the ActRIIB.hFc trap, however our combination blocks two specific ligands compared to the many ligands the receptor trap will inhibit. The difference in gene expression between these groups demonstrates that despite producing similar muscle growth, the trap affecting more genes in muscle without producing additional muscle hypertrophy.