Phosphorylase Kinase Inhibition Therapy in Burns and Scalds

Severe burns and scalds almost always result in unsightly hypertrophic scarring. Among the important processes involved in scarring are fibroblast formation and transformation of fibroblasts into myofibroblasts. Myofibroblasts contain α-smooth muscle actin which has contractile properties and can lead to wound contraction and hypertrophic scarring. Phosphorylase kinase (PhK), expressed within 5 mins of injury, is among the earliest enzymes released after tissue damage. It is responsible for activation of NF-kB, which in turn activates over 200 different genes related to inflammation, fibroblastic proliferation, myofibroblast conversion, and eventual scar tissue formation. The sequence and approximate timing of events following injury include the following: activation of PhK (5 mins), followed by appearance of neutrophils (30 mins), macrophages (hours to days), fibroblasts (1 week) and myofibroblasts (2 weeks). Cytokines and growth factors secreted by macrophages include fibroblast growth factor (FGF) and transforming growth factors α and β (TGFα and TGFβ). Fibroblast growth factor is responsible for fibroblastic proliferation, and TGFβ1 for conversion of fibroblasts into myofibroblasts. After thermal injury, the use of topical curcumin, a non-competitive, selective PhK inhibitor that blocks PhK activity upstream of NF-kB activation, was found to be associated with more rapid and improved skin healing, as well as less severe or absent scarring.