Inhibition of experimental corneal neovascularization by exogenous mouse interferon-inducible protein-10

Abstract

Background It has been proved that as a chemokine,interferon-inducible protein-10(IP-10)can regulate the immuno-inflammatory reaction.Some new researches showed that IP-10 also played role in regulating the neovascular vessel formation.Corneal neovascularization (CNV) is associated with multiple cellular factors,but its mechanism is below clear. Objective The present study was to address the roles of exogenous mouse IP-10 in alkali burn-induced CNV. Methods Eighty-two SPF BALB/c mice were used in this experiment and grouped according to random number table.The corneal alkali burn models were established by putting the filter paper with 1 mol/L NaOH at the central corneas of the left eyes for 40 seconds.10 mg/L IP-10 was topically administered from the first day or 14 days after modeling in the early intervene group( 10 eyes)or middle-late intervene group(5 eyes).CNV area was measured as a percentage of whole cornea.0.2％ sodium hyaluronate(HA) as vehicle was utilized in the model control group.Angiogenic factor expression in corneal tissue in the early intervene group was quantified by reverse transcriptase polymerase chain reaction (RT-PCR)and compared with model control group.All animal experiments were performed in accordance with the Association for Research in Vision and Ophthalmology Statement for the Use of Animals in Ophthalmic and Vision Research and complied with the standards of Guidelines for the Care and Use of Laboratory Animals of Soochow University. Results The CNV percentage was(88.67±10.22) ％ in the model control mice,showing a significant increase in comparison with that of IP-10 early intervene group (70.06±12.21)％ (t=3.77,P=0.00).In 21 days after corneal alkali burn,the CNV percentage was(87.33±13.47)％ in the model control mice,and that of the IP-10 middle-late intervene group was ( 86.56± 12.47 ) ％ without significant difference between them ( t =1.26,P＞0.05 ).Two days or four days after IP-10 early intervene,the expressions of chemokine receptor type 3 ( CXCR3 ) in corneal tissue were significant higher than model control group( t =3.13,3.07,P＜0.05 ),but the expressions of vascular endothelial growth factor (VEGF) in cornea were lowed ( t =5.99,6.27,P＜0.01),and so were transforming growth factor-β1 (TGF-β1) (t =8.50,P＜0.01;t =4.53,P＜0.05).Conclusions The early topical administration of the exogenous mouse IP-10 can inhibit CNV by up-regulating CXCR3 expression and down-regulating VEGF and TGF-β1 expression in cornea.However,middle-later usage of the IP-10 is uneffective. Key words: Interferon-inducible protein-10; Corneal alkali burn; Corneal neovascularization