Zinc(II) ion promotes anti-inflammatory effects of rhSOD3 by increasing cellular association

Recently, we demonstrated that superoxide dismutase 3 (SOD3) is a strong candidate for biomedicine. Anti-oxidant function of SOD3 was accomplished without cell penetration, and it inhibited the inflammatory responses via non-enzymatic functions. SOD3 has the heparin binding domain associating cell surface. Interestingly, we found that $Zn^{2+}$ promotes transduction effects of recombinant human SOD3 (rhSOD3) by increasing uptake via the heparin binding domain (HBD). We demonstrated an uptake of rhSOD3 from media to cell lysate via HBD, resulting in an accumulation of rhSOD3 in the nucleus, which was promoted by the presence of $Zn^{2+}$. This resulted in increased inhibitory effects of rhSOD3 on NF-{\kappa}B and STAT3 signals in the presence of $Zn^{2+}$, which shows elevated association of rhSOD3 into the cells. These results suggest that an optimized procedure can help to enhance the inflammatory efficacy of rhSOD3, as a novel biomedicine.