Comparative transcriptomic studies to determine the molecular effects of titin mechanical knock-out in skeletal muscles

Mechanical knock-out (mKO) is a novel tool to study the role of mechanical proteins in physiology by ceasing their force transmission in vivo. Here, titin protein carriying TEV protease recognition site (TEVs-TTN) is cleaved in vivo by the AAV-driven overexpression of TEV protease (TEVp) in skeletal muscles. An acute form of myopathy appears encompassing myofiber atrophy, myonuclei internalization, mitochondrial mislocalization and aggregation, and intersticial fibrosis. To define the molecular pathways affected when titin mechanics are perturbed, we performed RNA-sequencing with WT and homozygous Tttin mKO at 3 different timempoints and heterozygous Titin mKO muscles including saline-injected (-TEVp) and AAV-injected legs (+TEVp). WT and homozygous titin mKO injected with saline or AAV and dissected at 3 different timepoints post-infection and heterozygous titin mKO muscles injected with saline and AAV and dissected at 7 days-post-infection.