TAT-mediated peroxiredoxin 5 and 6 protein transduction protects against high-glucose-induced cytotoxicity in retinal pericytes.
OBJECTIVE
Hyperglycemia-induced oxidative stress is implicated in pericyte apoptosis seen in diabetic retinopathy. The six mammalian Peroxiredoxins (PRDXs) comprise a novel family of antioxidative proteins that negatively regulate oxidative stress-induced apoptosis by controlling reactive oxygen species (ROS) levels.


METHODS
Sprague-Dawley rats were used to detect the retinal expressions of PRDXs1-6. Pig pericytes cultured in high-glucose medium were used to monitor the protective effect of PRDX5 and 6 against high-glucose-associated change. Recombinant PRDX5 and 6 proteins were linked to the Trans-Activating Transduction (TAT) domain from HIV-1 TAT protein for their efficient delivery into cells/tissues.


RESULTS
We found higher expression of PRDX5 and 6 mRNAs and PRDX5 and 6 proteins in retina than the other Prdxs (Prdx1-4). Western blotting affirmed the intracellular presence of TAT-linked proteins and revealed the efficient transduction of TAT-HA-PRDX5 and 6 in these cells. Extrinsic supply of TAT-HA-PRDX5 and 6 proteins inhibited the oxidative stress-induced DNA damage after high-glucose exposure in pig pericytes. The cell survival and apoptosis assay revealed that extrinsic supply of TAT-HA-PRDX5 and 6 proteins was responsible for inhibiting hyperglycemia-induced pericyte apoptosis.


CONCLUSIONS
Results suggest that delivery of PRDX5 and 6 might protect hyperglycemia-induced pericyte loss to inhibit oxidative stress.
Kubo
Eri
E
Department of Ophthalmology, University of Fukui, Fukui, Japan. kuboe@u-fukui.ac.jp
Singh
Dhirendra P
DP
Fatma
Nigar
N
Akagi
Yoshio
Y
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002478:Cells, Cultured; D005260:Female; D005947:Glucose / Q000633:toxicity*; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006801:Humans; D020286:Pericytes / Q000378:metabolism* / Q000473:pathology; D054465:Peroxiredoxin VI / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics*; D054464:Peroxiredoxins / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000008:administration & dosage; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D013552:Swine; D014161:Transduction, Genetic; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000502:physiology*
D011994:Recombinant Proteins; D054322:tat Gene Products, Human Immunodeficiency Virus; D054465:Peroxiredoxin VI; D054464:Peroxiredoxins; C515984:Prdx6 protein, rat; D005947:Glucose