Common Gene Transcriptional Patterns Following Immobilization, Spinal Cord Injury, and Unloading in Human Skeletal Muscle

Following spinal cord injury, skeletal muscle loss is rapid. This severe atrophy is attributed to declines in protein synthesis and increases in protein breakdown. However, the signaling mechanisms controlling these changes are not well understood. Nine male patients and one female patient with spinal cord injury (SCI) (Mean SEM = 43.9 6.7 yrs) were recruited for this study. Six patients were quadriplegics and four patients were paraplegics. Inclusion criteria were as follows: patients above the age of 18 yrs, absence of severe brain injury (Glasgow Coma Scale > 13), absence of muscle-crush injury or compartment syndrome, absence of all of the following conditions: hypoxic injury, systemic sepsis, systemic inflammatory or autoimmune disease, and malignancy. Muscle biopsies were obtained from the vastus lateralis muscles of the SCI patients two days and five days post-SCI. Biopsies collected two days post-SCI were included in the current analysis. Expression changes were measured by microarray and gene clustering; identification of enriched functions and canonical pathways were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Ingenuity Pathway Analysis (IPA).

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Reich KA, Chen YW, Thompson PD, Hoffman EP, Clarkson PM