Influence of low and high force muscle activity on paralyzed muscle gene expression

We used a novel approach to study the acute effect of two frequencies of stimulation (20 Hz and 5 Hz; high and low force, respectively) on gene regulation in people with chronic paralysis. Three hours after the completion of the electrical stimulation protocol (5 Hz or 20 Hz), we sampled the vastus lateralis muscle and examined genes involved with metabolic transcription, glycolysis, oxidative phosphorylation, and mitochondria remodelling. We discovered that the 5 Hz stimulation, despite generating a lower overall force, induced a 5-6 fold increase (p<0.05) in key metabolic transcription factors including PGC-1α, NR4A3, and ABRA. Neither protocol showed a robust regulation of genes for glycolysis, oxidative phosphorylation, and mitochondria remodelling. We analyzed skeletal muscle using the Affymetrix Human Exon 1.0 ST platform. Array data was processed by Partek Genomic Suites.