Tsukushi is involved in the wound healing by regulating the expression of cytokines and growth factors

During the wound-healing process, macrophages, fibroblasts, and myofibroblasts play a leading role in shifting from the inflammation phase to the proliferation phase, although little is known about the cell differentiation and molecular control mechanisms underlying these processes. Previously, we reported that Tsukushi (TSK), a member of the small leucine-rich repeat proteoglycan family, functions as a key extracellular coordinator of multiple signalling networks. In this study, we investigated the contribution of TSK to wound healing. Analysis of wound tissue in heterozygous TSK-lacZ knock-in mice revealed a pattern of sequential TSK expression from macrophages to myofibroblasts. Quantitative PCR and in vitro cell induction experiments showed that TSK controls macrophage function and myofibroblast differentiation by inhibiting TGF-beta 1 secreted from macrophages. Our results suggest TSK facilitates wound healing by maintaining inflammatory cell quiescence.