Cytokine networks in immune-mediated muscle regeneration

Mechanisms underlying early inflammation and subsequent muscle repair after injury are typically described in terms of the coordinated action of numerous waves of immune cells. It is now emerging, however, that a complex network of leukocyte- and stromal cell-derived cytokines orchestrate the early infiltration and function of pro-inflammatory leukocytes and underlies subsequent immune-mediated repair and regenerative responses. This review discusses how recently defined cytokines fit into the previously outlined cytokine networks shaping tissue damage and repair after injury. We also discuss new roles for previously well-characterized cytokines in muscle injury and repair responses. Finally, we summarize how modulation of local and systemic cytokine networks involved in muscle injury and repair by synthetic and naturally-derived biomaterials and stem cells is showing promise as a clinically applicable means to promote muscle regeneration and improve function after volumetric muscle loss and other muscle diseases.