Thrombin in peripheral nerves: friend or foe?

Differently from the central nervous system (CNS), the peripheral nervous system (PNS) exhibits a high regenerative capacity. This ability is related to the remarkable plasticity of Schwann cells (SCs) which after nerve injury convert to a repair-promoting phenotype to a large extent. Nerve injury is accompanied by a rapid rise of thrombin levels (Bushi et al., 2016; Gera et al., 2016). Thrombin is the key effector protease of the coagulation cascade which elicits hormonelike actions by the activation of G-protein coupled receptors known as proteaseactivated receptors (PARs). Inflammation and coagulation are two complex and interconnected pathways whose mutual interactions have been only partially elucidated.