Transgenic mouse models of muscle aging.

In the last decade transgenic animals have been become a powerful and exciting research model to study the molecular mechanisms underlying the cellular and physiological processes such as cell growth, differentiation, apoptosis, and the regulation of specific gene expression. In the context of skeletal muscle development, transgenic mice and gene-targeting approaches have led to the definition of specific roles for Muscle Regulatory Factors (MRFs) during embryogenesis, although less is known about the molecular mechanism underlying skeletal muscle aging. Recent studies using specific models of transgenic mice have added new insights into the muscle aging process, providing a baseline for designing appropriate strategies to attenuate or to reverse the cumulative effects of aging. In this review we discuss some of the transgenic models currently available to address the molecular mechanisms of skeletal muscle senescence. Given the complexity of the aging process, this review should be regarded as a presentation of works in progress rather than a comprehensive description of muscle aging.