Angiotensin-II as a Trigger Factor in the Development of Retinopathy of Prematurity

The multifactorial nature of the retinopathy of prematurity (ROP) pathogenesis, makes the thorough study of the mechanism of pathological retinal neovascularization actual. However recently the attention of scientists has been attracted by the participation of renin-angiotensin system (RAS) in the development of retinal vasoproliferative diseases. Purpose: to study the role of AT-II in the pathogenesis of experimental ROP (EROP) in the original model of the disease. Material and methods. To reproduce EROP Wistar rats (n = 15) were exposed to the oxygen concentration varying from 60 to 15% every 12 hours for 14 days from the first day after birth followed by room air for 7 days. Throughout the experiment, the room maintained a constant temperature (+26 °C) and light regime (12 hours a day, 12 hours a night) modes. Control rats (n = 12) were born and kept under normal oxygen content (21 %). Batches of EROP (n = 5) and control (n = 4) rats were sacrificed on 7, 14 and 21 days. All rats underwent binocular enucleation, after which every eyeball was opened on the limb, the cornea and lens were removed with the remains of a persistent vascular bag and a hyaloid artery. Retinas were isolated, homogenized and stored at -20 °C. Angiotensin-II (AT-II) in homogenates was measured using the IFA kit. Results. On the 7th day of the experiment, the level of AT-II in the retina of the experimental group rats was 0.19 ± 0.02 pg/mg protein that was significantly higher than in controls (0.12 ± 0.01 pg/mg protein). On the 14th and 21st days concentrations of AT-II in EROP and control groups had no significant difference. Conclusion. On the 7th day of the experiment, i.e. at the period corresponding to the existence of avascular retinal zones in both groups concentration of AT-II in the retinas of rats with EROP was significantly higher than in controls. This fact indicate the role of this proangiogenic factor in the induction of pathological neovascularization in ROP. Possible prognostic function of this parameter during the period before ROP manifestation has undoubted practical significance.

retinopathy of prematurity, rat model, pathogenesis, renin-angiotensin system

1. Yonekawa Y., Thomas B.J., Thanos A., Todorich B., Drenser K.A., Trese M.T., Capone A. Jr. The cutting edge of retinopathy of prematurity care: expanding the boundaries of diagnosis and treatment. Retina. 2017;37(12):2208–2225. DOI: 10.1097/IAE.0000000000001719

2. Katargina L.A., Slepova O.S., Demchenko E.N., Osipova N.A. The role of the systemic disbalance of serum cytokine levels in pathogenesis of retinopathy of prematurity. Russian Pediatric Ophthalmology = Rossijskaya pediatricheskaya ophthlmologija. 2015;4:16–20 (In Russ.).

3. Wagner J., Jan Danser A.H., Derkx F.H., de Jong T.V., Paul M., Mullins J.J., Schalekamp M.A., Ganten D. Demonstration of renin mRNA, angiotensinogen m RNA, and angiotensin converting enzyme mRNA expression in the human eye: evidence for the intraocular renin angiotensin system. British Journal of Ophthalmology. 1996;80:159–163. PMID: 8814748

4. Sarlos S., Wilkinson-Berka J.L. The renin-angiotensin system and the developing retinal vasculature. Invest. Ophthalmol. Vis. Sci. 2005;46(3):1069–1077. DOI: 10.1167/iovs.04-0885. PMID: 15728567

5. Chaturvedi N., Sjolie A.K., Stephenson J.M., Abrahamian H., Keipes M., Castellarin A., Rogulja-Pepeonik Z., Fuller J.H. Effect of lisinopril on progression of retinopathy in normotensive people with type 1 diabetes. Lancet. 1998;351:28–31. PMID: 9433426

6. Moravski C.J., Skinner S.L., Stubbs A.J. The renin-angiotensinsystem influences ocular endothelial cell proliferation in diabetes: transgenic and interventional studies. Am. J. Pathol. 2003;162:151–160. DOI: 10.1016/S0002-9440(10)63806-0. PMID: 12507898

7. Kle Gilbert R.E., Kelly D.J., Cox A.J. Angiotensin converting enzyme inhibition reduces retinal overexpression of vascular endothelial growth factor and hyperpermeability in experimental diabetes. Diabetologia. 2000;43:1360–1367. DOI: 10.1007/s001250051539. PMID: 11126403

8. Lonchampt M., Pennel L., Dubault J. Hyperoxia/normoxia-driven retinal angiogenesis in mice: A role for angiotensin II. Invest. Ophthalmol. Vis. Sci. 2002;42:429–432.

9. Downie L.E., Hatzopoulos K.M., Pianta M.J., Vingrys A.J., Wilkinson-Berka J.L., Kalloniatis M., Fletcher E.L. Angiotensin type-I receptor inhibition neuroprotective to amacrine cells in a rat model of retinopathy of prematurity. J. Comp. Neur. 2010;1;518(1):41–63. DOI: 10.1002/cne.22205. PMID: 19882719

10. Nath M., Chandra P., Halder N., Singh B., Deorari A.K., Kumar A., Azad R., Velpandian T. Involvement of Renin-Angiotensin System in Retinopathy of Prematurity — A Possible Target for Therapeutic Intervention. PLoS One. 2016;11(12):0168809. DOI: 10.1371

11. Sarlos S., Rizkalla B., Moravski C.J., Cao Z., Cooper M.E., Wilkinson-Berka J.L. Retinal angiogenesis is mediated by an interaction between the angiotensin type 2 receptor, VEGF, and angiopoietin. Am. J. Pathol. 2003;163(3):879–887.

12. Tamarat R., Silvestre J.S., Durie M., Levy B.I. Angiotensin II angiogenic effect in vivo involves vascular endothelial growth factorand inflammation-related pathways. Lab. Invest. 2002;82:747–756.

13. Asahara T., Chen D., Takahashi T., Fujikawa K., Kearney M., Magner M., Yancopoulos G.D., Isner J.M. Tie2 receptor ligands, angiopoietin-1 and angiopoietin-2, modulate VEGF-induced postnatal neovascularization. Circ. Res. 1998;83:233–240.

14. Lowry O., Rozebrough N., Farr A., Randell R. Protein mеasurement with the folin phenol reagent. J. Bio. Chem. 1951;193:265–275.

15. Katargina L.A., Khoroshilova-Maslova I.P., Maybogin M.A., Panova I.G., Osipova N.A. Pathomorphological features of the development of experimental retinopathy of prematurity. International Journal of Applied and Basic Research = Mezhdunarodnyj zhurnal prikladnyh i fundamental’nyh issledovanij. 2017;3(2):190–194 (In Russ.).

16. Quinn G.E., Ying G.S., Bell E.F., Donohue P.K., Morrison D., Tomlinson L.A., Binenbaum G. G-ROP Study Group. Incidence and Early Course of Retinopathy of Prematurity: Secondary Analysis of the Postnatal Growth and Retinopathy of Prematurity (G-ROP) Study. JAMA Ophthalmol. 2018;136(12):1383–1389. DOI: 10.1001/jamaophthalmol.2018.4290

17. Chen J., Stahl A., Hellstrom A., Smith L.E. Current update on retinopathy of prematurity: screening and treatment. Curr. Opin. Pediatr. 2011;23(2):173–178.