Quantitative proteomics analysis of deer antlerogenic periosteal cells reveals potential bioactive factors in velvet antlers

Abstract

Velvet antlers (VA) have been used as medicines and nutraceuticals for over 2000 years. Meanwhile, deer antlers are the only mammalian organs that can fully regenerate after annual shedding. The antler formation and regeneration rely on the stem cells resident in antlerogenic periosteum (AP), transplantation of which can induce ectopic antler formation. Here, a comprehensive quantitative proteomic analysis of antlerogenic periosteal cells (AP cells), compared with the adjacent facial periosteal cells (FP cells), was carried out, from both extracellular and intracellular perspectives. In this study, the stable isotope labeling by amino acids in cell culture (SILAC) was applied to ensure the precision of quantification. Then, the protein equalization strategy and reverse-phase liquid chromatography (RPLC) separation in high pH were utilized to improve the depth of proteome profiling. Proteomics analysis of the conditioned media (CM) from AP and FP cells showed that significantly over-expressed extracellular proteins in AP cells were involved in cell proliferation, angiogenesis and neurogenesis. Combining the extracellular and intracellular proteomes, we found several potential secreted proteins might regulate antler formation and regeneration, such as SFRP4 and LUM. These results provide new insight into the underlying mechanism of antler formation and regeneration.