Mitochondria-targeted antioxidant peptide SS31 attenuates high glucose-induced injury on human retinal endothelial cells.
OBJECTIVE
To investigate the effect of mitochondria-targeted antioxidant peptide SS31 on prevention of high glucose-induced injury on human retinal endothelial cells (HRECs).


METHODS
Cultured P3-P5 HRECs were divided into three groups: 5 mM glucose group, 30 mM glucose group and 30 mM glucose co-treated with 100 nM SS31 group. 24 and 48 h after treatment, Annexin V-FITC/PI staining was used to evaluate the survival of HRECs. Overproduction of ROS was assessed by MitoSOX staining under confocal microscope. Change of mitochondrial potential (ΔΨ(m)) of HRECs was measured by flow cytometry after JC-1 fluorescent probe staining. Release of cytochrome c was assessed by confocal microscopy and western blot. Expression of caspase-3 and thioredoxin-2 (Trx-2) were measured by western blot and real-time PCR.


RESULTS
Compared to the high glucose group, co-treatment with 100 nM SS31 significantly protected HRECs from high glucose-induced injury, reduced the production of ROS in mitochondria, stabilized ΔΨ(m), decreased the release of cytochrome c from mitochondria to cytoplasm, decreased the expression of caspase-3 and increased the expression of Trx-2 in high glucose-treated HRECs.


CONCLUSIONS
SS31 attenuates the high glucose-induced injuries on HRECs by stabilizing ΔΨ(m), decreasing ROS production, preventing the release of cytochrome c from mitochondria, decreasing the expression of caspase-3 and increasing the expression of Trx-2. Our study suggests that SS31 may be as a potential new treatment for diabetic retinopathy and other oxidative stress-related diseases.
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou 510060, PR China.
Jianqiao
J
Li
Xiaoyun
X
Chen
Wei
W
Xiao
Wei
W
Ma
Tao
T
Li
Juan
J
Huang
Xialin
X
Liu
Xiaoling
X
Liang
Shibo
S
Tang
Yan
Y
Luo
D000975:Antioxidants / Q000494:pharmacology* / Q000627:therapeutic use; D053148:Caspase 3 / Q000096:biosynthesis; D061945:Caspase Inhibitors; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000188:drug therapy / Q000209:etiology*; D042783:Endothelial Cells / Q000187:drug effects*; D005947:Glucose / Q000633:toxicity*; D006801:Humans; D006943:Hyperglycemia / Q000150:complications*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D024101:Mitochondrial Proteins / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology* / Q000627:therapeutic use; D012160:Retina / Q000187:drug effects*; D013879:Thioredoxins / Q000378:metabolism
D000975:Antioxidants; D061945:Caspase Inhibitors; D024101:Mitochondrial Proteins; D009842:Oligopeptides; C467002:TXN2 protein, human; C506540:arginyl-2,'6'-dimethyltyrosyl-lysyl-phenylalaninamide; D013879:Thioredoxins; D045304:Cytochromes c; D053148:Caspase 3; D005947:Glucose