SDC1 and staphylococcus aureus infection: In vivo, when SDC1 shedding is induced by Staphylococcus aureus infections in the lung, it's cell surface expression assessed by flow cytometry is maintained presumably by cells increasing surface expression of SDC1 from intracellular vesicles.86 Taken together, data show that when cells that express SDC1 are stressed, they maintain cell surface HSPG expression by increasing synthesis of other HSPG core proteins.