The role of supplemental oxygen and JAK/STAT signaling in intravitreous neovascularization in a ROP rat model.
OBJECTIVE
To investigate whether oxygen stresses experienced in retinopathy of prematurity (ROP) trigger signaling through reactive oxygen species (ROS) and whether the Janus kinase-signal transducer and activator of transcription (JAK/STAT) pathway lead to intravitreous neovascularization (IVNV) in an oxygen-induced retinopathy (OIR) rat model.


METHODS
Newborn rat pups exposed to repeated fluctuations in oxygen and rescued in supplemental oxygen (28% O(2), 50/10 OIR+SO) were treated with apocynin, an NADPH oxidase and ROS inhibitor (10 mg/kg/d), AG490, a JAK2 inhibitor (5 mg/kg/d), or phosphate-buffered saline. Intraperitoneal injections were given from postnatal day (P)12 to P17 (apocynin), or from P3 to P17 (AG490). Outcomes were intravitreous neovascularization and avascular/total retinal areas, vascular endothelial growth factor, phosphorylated JAK2, and phosphorylated STAT3.


RESULTS
Apocynin significantly reduced phosphorylated STAT3 in 50/10 OIR+SO (P = 0.04), in association with previously reported inhibition of the IVNV area. Inhibition of JAK with AG490 significantly reduced phosphorylated JAK2 (P < 0.001), phosphorylated STAT3 (P = 0.002), and IVNV area (P = 0.033) in the 50/10 OIR+SO model compared with control.


CONCLUSIONS
Activation of NADPH oxidase from supplemental oxygen works through activated STAT3 to lead to IVNV. In addition, inhibition of the JAK/STAT pathway reduces IVNV. Further studies are needed to determine the effects and relationships of oxygen stresses on JAK/STAT and NAPDH oxidase signaling.
Byfield
Grace
G
Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina 27599-7041, USA.
Budd
Steve
S
Hartnett
M Elizabeth
ME
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D018496:Hyperoxia / Q000378:metabolism*; D007231:Infant, Newborn; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors / Q000502:physiology*; D019255:NADPH Oxidases / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species; D012171:Retinal Vessels / Q000378:metabolism / Q000473:pathology; D012178:Retinopathy of Prematurity / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D020032:Tyrphostins / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014822:Vitreous Body / Q000098:blood supply*
D000098:Acetophenones; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat; D020032:Tyrphostins; D042461:Vascular Endothelial Growth Factor A; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; C467498:vascular endothelial growth factor A, rat; C056165:acetovanillone; D019255:NADPH Oxidases; C507927:Jak2 protein, rat; D053614:Janus Kinase 2