The effect of tissue plasminogen activator on corticosteroid-induced ocular hypertension in guinea pig–a next generation proteomic study

Sze Wan Shan, Kit Ying Choy, King Kit Li, Bing Zuo, Ka Man Chun, Chi Ho To

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Purpose : This project studied the reaction of tissue plasminogen activator (tPA) on corticosteroid-induced ocular hypertension (CIH) and glaucoma using a guinea pig animal model. The molecular mechanism underlying was also explored.

Methods : Ocular hypertension in guinea pigs was induced by sub-conjunctival injection of 5% dexamethasone (DEX) into both eyes. After 6 weeks, tPA was then injected into the treated eyes while PBS was used to inject into contralateral eyes. Trabecular meshwork (TM) tissue in both eyes of the guinea pigs were then collected for proteomic analysis after intraocular pressure (IOP) measurement. Differentially expressed proteins were quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS) using SWATHTM technologies.

Results : The average IOP at baseline was 18.5 ± 2.8 mmHg (mean ± SD) and 18.7 ± 2.8 mmHg (mean ± SD) in both eyes respectively. After 6 weeks of DEX treatment, IOPs increased to 22.9 ± 2.2 mmHg (mean ± SD) and 23.1 ± 2.8 mmHg (mean ± SD) in both eyes respectively. The average inter-ocular difference (IOD, treated minus control IOP) of IOP between 2 eyes was, at day 0 of injection, - 0.2 ± 0.8 mmHg (mean ± SD) while it reached - 6.7 ± 1.6 mmHg (mean ± SD) after 2 days of tPA treatment. IOPs of the tPA-treated eyes were lower than the contralateral eyes. Eight differentially expressed proteins (p-value ≤ 0.05 and fold-change ≥1.3 or ≤ 0.77) were identified by SWATH-MS. Among them, phospholipid scramblase (PLSCR3) was found to be regulated by tPA in CIH TM tissue of guinea pigs. It was found that phospholipid scramblase activity was regulated in a genome-wide association study of glaucoma subjects.

Conclusions : An albino guinea pig CIH model was successfully developed and IOP could be induced after 6 weeks of DEX injection via subconjunctiva. tPA was found to significantly reduce the IOP in CIH guinea pig’s eyes. Our results revealed that tPA can also regulate multiple differentially expressed proteins. Furthermore, our result will inform new clinical study to assess the development of a novel therapeutic drug in patients with glaucoma.
Original languageEnglish
Title of host publicationInvestigative Ophthalmology & Visual Science
Pages3288
Volume63
ISBN (Electronic)1552-5783
Publication statusPublished - Jun 2022
EventAssociation for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2022 - Denver, United States
Duration: 1 May 20224 May 2022

Conference

ConferenceAssociation for Research in Vision and Ophthalmology (ARVO) Annual Meeting 2022
Abbreviated titleARVO 2022
Country/TerritoryUnited States
CityDenver
Period1/05/224/05/22

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