Skeletal muscle regeneration and the role of regeneration genes

Skeletni mišić odraslog organizma je dinamično tkivo koje ima iznimnu sposobnost regeneracije nakon ozljede. Radi se o sinkroniziranim procesima koji uključuju aktivaciju populacije mišićnih prekursora koje nazivamo satelitskim stanicama. Nakon povrede skeletni mišić vrlo brzo započinje s opsežnim procesima reparacije s ciljem prevencije gubitka mišićne mase. Inicijalna faza mišićne regeneracije i reparacije karakterizirana je nekrozom oštećenog tkiva i upalom. Gotovo istodobno aktiviraju se do tada mirne satelitske stanice, proliferiraju, diferenciraju i spajaju se kako bi nastalo multinuklearno mišićno vlakno. U procesu mišićne regeneracije značajnu funkciju imaju i proteini regeneracijske (Reg) genske obitelji. Obitelj Reg gena uključena je u proces regeneracije tkiva, rast i proliferaciju različitih stanica, staničnu adheziju i otpornost na apoptozu. Reg geni očituju se u ranim fazama ozljede, što upućuje na njihovu ulogu reaktanta akutne faze upale i faktora rasta koji uzrokuje proliferaciju i rast satelitskih stanica u skeletnom mišiću, odnosno proliferaciju i rast Schwannovih stanica u ozlijeđenom perifernom živcu. Budući da se Reg 3G pojavljuje odmah nakon ozljede mišića i živca, pretpostavlja se da ima ulogu posrednika u signaliranju između ozlijeđenog živca i mišića, a moguće i makrofaga.Adult skeletal muscle is an extremely dynamic tissue which has a tremendous ability of regeneration after muscle injury. These processes are highly synchronized involving the activation of well-defined population of muscle stem cells called satellite cells. After injury skeletal muscle initiate a rapid and extensive repair process preventing the loss of muscle mass. The initial phase of muscle regeneration and repair is characterized by necrosis of the damaged tissue and inflammation. Almost simultaneously previous quiescent satellite cells are activated, proliferate, differentiate and fuse to form multinucleated myofibers. The regenerating (Reg) protein family has important role in the process of muscle regeneration. Reg proteins play important roles in tissue regeneration, cell growth and proliferation, cell adhesion and resistance to apoptosis. A Reg3G gene is upregulated in the early phase of muscle injury and acts as acute phase reactants and growth factor for muscle satellite cells and injured Schwann cells. Since the induction and release of Reg3G appeared to readily respond to muscle and nerve injury, Reg3G may function as mediators of the injury signal among the injured nerve and muscle, and possibly macrophages