Epigenetics and regenerative medicine: neural and skeletal muscle perspectives

Throughout organism development and during normal tissue homeostasis, progenitor cells undergo dramatic changes in gene expression to adapt to new functions. Such reprogramming is strongly dependent on epigenetic mechanisms. As these processes are, at least partially, recapitulated after tissue damage, they are attractive targets for the stimulation of tissue regeneration.Mammalian tissues vary in their regenerative capabilities. Some tissues, such as the liver or skeletal muscle possess the capacity to support complete regeneration, reacquiring tissue function. On the other hand, organs such as the brain or epidermis usually undergo processes of repair, resolving tissue damage through the formation of nonfunctional tissue, which is referred to as a scar. Regenerative medicine aims at facilitating the restoration of the function of damaged tissues. It exploits various techniques towards this goal-that is, gene therapy and cell replacement. A further tool of regenerative medicine is the use of drugs that target key players in epigenetic processes, with the ultimate goal of exploiting the common epigenetic properties of development and tissue homeostasis to facilitate regeneration.In this chapter, we cover the central nervous system (CNS) and skeletal muscle due to these tissues being on opposite sides of the aforementioned spectrum of regenerative capabilities. We introduce tissue homeostatic properties of both systems, putting emphasis on epigenetic processes. For the two tissues, we also discuss commonly encountered types of damage. Finally, we explore strategies to overcome tissue damage through targeting of the epigenetic machinery, emphasizing the differences and similarities between these two distinct tissues. We conclude the chapter with a concise discussion of how the epigenetic consequences of aging influence tissue homeostasis and regeneration.