Regulation of skeletal muscle development and disease by microRNAs.

The identification of microRNAs (miRNA) in vertebrates has uncovered new mechanisms regulating skeletal muscle development and disease. miRNAs are inhibitors and act by silencing specific mRNAs or by repressing protein translation. In many cases, miRNAs are involved in physiological or pathological stress, suggesting they function to exacerbate or protect the organism during stress or disease. Although many skeletal muscle diseases differ in clinical and pathological manifestations, they all have a common feature of dysregulation of miRNA expression. In particular, analysis of miRNA expression patterns in skeletal muscle diseases reveals miRNA signatures, showing many miRNAs are dysregulated during disease. Emerging identification of miRNA targets and involvement in genetic regulatory networks serve to reveal new regulatory pathways in skeletal muscle biology. This chapter features the findings pertaining to skeletal muscle miRNAs in skeletal muscle development and disease and highlights therapeutic applications of miRNA-based technology in diagnosis and treatment of skeletal muscle myopathies.