Proteomic analysis of a targeted functional genomic screen in human skeletal muscle organoids

To begin to validate potential causal regulators of muscle function, we targeted genes containing novel skeletal muscle pQTLs and molecular/phenotypic associations, and performed a functional genomic screen in human skeletal muscle organoids (PMID: 30527761). We focused on proteins with negative associations to lean mass, grip strength or other metabolic associations, and generated a total of 27 individual rAAV6:shRNAs. Organoids were grown around contraction posts to monitor contractile force production during electrical stimulation, and transduced following differentiation and maturation to limit effects on the myogenic program (Figure 3A). Electrical stimulation was performed to induce either a tetanic contraction for assessment of maximum force production or stimulated with sustained lower frequency for assessment of fatigue. Following the protocol, organoids were analysed by proteomics which quantified 17/27 targets with 13 targets significantly reduced in abundance by rAAV6:shRNA.