Engineered Sumoylation-Deficient Prdx6 Mutant Protein-Loaded Nanoparticles Provide Increased Cellular Defense and Prevent Lens Opacity

Aberrant Sumoylation-mediated protein dysfunction is involved in a variety of oxidative and aging pathologies. We previously reported that Sumoylation-deficient Prdx6K((lysine)122/142R(Arginine)) linked to the TAT-transduction domain gained stability and protective efficacy. In the present study, we formulated wild-type TAT-HA-Prdx6(WT) and Sumoylation-deficient Prdx6-loaded poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) to further enhance stability, protective activities, and sustained delivery. We found that in vitro and subconjuctival delivery of Sumoylation-deficient Prdx6-NPs provided a greater protection of lens epithelial cells (LECs) derived from human and Prdx6(-/-)-deficient mouse lenses against oxidative stress, and it also delayed the lens opacity in Shumiya cataract rats (SCRs) than TAT-HA-Prdx6(WT)-NPs. The encapsulation efficiencies of TAT-HA-Prdx6-NPs were approximate to 56%-62%. Dynamic light scattering (DLS) and atomic force microscopy (AFM) analyses showed that the NPs were spherical, with a size of 50-250 nm and a negative zeta potential (approximate to 23 mV). TAT-HA-Prdx6 analog-NPs released bioactive TAT-HA-Prdx6 (6%-7%) within 24 h. Sumoylation-deficient TAT-HA-Prdx6-NPs provided 35% more protection by reducing the oxidative load of LECs exposed to H2O2 compared to TAT-HA-Prdx6(WT)-NPs. A subconjuctival delivery of TAT-HA-Prdx6 analog-NPs demonstrated that released TAT-HA-Prdx6(K122/142R) could reduce lens opacity by approximate to 60% in SCRs. Collectively, our results demonstrate for the first time that the subconjuctival delivery of Sumoylation-deficient Prdx6-NPs is efficiently cytoprotective and provide a proof of concept for potential use to delay cataract and oxidative-related pathobiology in general.

Automated summary

Subconjunctival delivery of Sumoylation-deficient Prdx6-loaded NPs provided enhanced cytoprotective effects against oxidative stress in lens epithelial cells and delayed lens opacity in cataract rats compared to wild-type Prdx6-loaded NPs. This study demonstrates the potential of subconjunctival delivery of Sumoylation-deficient Prdx6-NPs in delaying cataract and oxidative-related pathobiology.