Table 2.

Studies on the effects of oxidative stress in RPE cells.

S.No	Model	Method Used	Effect Of Oxidative Stress	Reference
1	Mice	•Cell proliferation assay •Apoptosis assay •Western blotting •ROS assessments.	RPE cells were more migratory under high glucose conditions. High glucose condition increased the level of oxidative stress and has minimal effect on RPE cells proliferation and apoptosis.	186
2	RPE cell lines	•Cell transfection •MTT assay •ATP level assessment •ROS detection •Immunocytochemistry	Identified GAA as a potential inhibitor of oxidative stress-induced RPE cell death by regulating FoxO3/SESN2 pathway	34
4	Human monocytic cell lines, hfRPE and NaIO3 mouse models	•TUNEL staining •Immunohistochemistry •Western blot •qPCR •ELISA	TLR2 induces oxidative stress and causes retinal degeneration.	36
5.	Mice	•SD-OCT •Electroretinography •Immunohistochemistry •RT-PCR •mtDNA copy number analysis •ATP measurement •Image quantifications	•Mitochondrial oxidative stress •Mitochondrial damage •RPE alterations (morphology, function)	20
6.	ARPE-19 cell line	•Annexin V-FITC/PI assay •ROS detection •Western blot •Oxygen consumption rate assessment •Mitochondrial imaging	•Sodium iodate induced cytotoxicity. •Mitochondrial fragmentation •Autophagy inhibition	21
7	ARPE-19 cell line	•Cell viability •ROS measurement •RNA isolation and microarray •RT-qPCR •Gene ontology •Western blotting •ATP assessment and proteasome activity assay •Imuunohistochemistry	•Storage of superoxide and decreased ATP production	30
8	Human RPE cells from AMD patients	•RPE cell culture •H2O2 assessment •mtDNA lesion and repair measurement •mtDNA mutations assessment •Western blot analysis	•↑mtDNA damage •↓mtDNA repair system •mtDNA mutations were observed in AMD patients	26
9.	Human RPE cells from AMD patients	•Electron microscopy •Morphometry	•↓ number of mitochondria •Proliferation of peroxisomes and lipofuscin •Morphological alterations of RPE	28
10.	Human RPE cells from AMD patients	•DNA isolation •LX-PCR •qRT-PCR	•↑mtDNA damage •↑mtDNA deletion	29

RPE: retinal pigment epithelium; ROS: reactive-oxygen species; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium; ATP: adenosine triphosphate; SESN2: sestrin 2; FoxO3: Forkhead box O3 transcription factor; GAA: acetic acid; hfRPE: human fetal RPE; NaIO3: sodium iodate; TUNEL: terminal deoxynucleotidyltransferasedUTP nick end labeling; qPCR: quantitative polymerase chain reaction; ELISA: enzyme linked immunosorbent assay; SD-OCT: spectral-domain optical coherence tomography; RT-PCR: real-time polymerase chain reaction; mtDNA: mitochondrial DNA; TLR2: toll-like receptor 2; FITC: fluorescein isothiocyante; H₂O₂: hydrogen peroxide; LX-PCR: long extension polymerase chain reaction.