Egr-1 mRNA expression is a marker for the direction of mammalian ocular growth.

Autor:	Ashby RS; Vision Sciences Group, School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales, Australia., Zeng G; Vision Sciences Group, School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales, Australia Department of Ophthalmology, Daqing Oilfield General Hospital, Saertu, Daqing, China., Leotta AJ; Vision Sciences Group, School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales, Australia., Tse DY; Vision Sciences Group, School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales, Australia School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong., McFadden SA; Vision Sciences Group, School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales, Australia.
Jazyk:	angličtina
Zdroj:	Investigative ophthalmology & visual science [Invest Ophthalmol Vis Sci] 2014 Jul 22; Vol. 55 (9), pp. 5911-21. Date of Electronic Publication: 2014 Jul 22.
DOI:	10.1167/iovs.13-11708
Abstrakt:	Purpose: The immediate early gene Egr-1 is thought to form part of the pathway that mediates abnormal ocular growth. This study investigated whether the mRNA expression levels of Egr-1 in a mammalian retina are modulated differentially, depending on the direction of ocular growth. Methods: To induce accelerated growth and myopia, guinea pigs wore a -5 diopter (D) lens over one eye from 4 to 11 days of age. To induce inhibited growth, the lens was removed after 7 days of -5 D lens wear, and the eye allowed to recover from myopia for 3 days. Ocular parameters and Egr-1 mRNA levels were subsequently assessed, and compared to untreated fellow eyes and eyes from untreated littermates. Possible circadian changes in Egr-1 mRNA levels were also determined in 18 additional animals by taking measures every 4 hours during a 24-hour cycle. Results: Ocular compensation to a -5 D lens occurred after 7 days (Δ -4.8 D, Δ +147 μm growth, N = 20). In 5 highly myopic eyes (Δ -7.4 D), Egr-1 mRNA levels in the retina were significantly downregulated relative to contralateral control (51%) and age-matched untreated (47%) eyes. Three days after the -5 D lens was removed, eyes had recovered from the myopia (Δ -0.5 D, relative change of +2.9 D, N = 4) and Egr-1 mRNA levels were significantly elevated relative to contralateral (212%) and untreated (234%) eyes, respectively. Normal Egr-1 mRNA expression was higher in the middle of the day than in the middle of the night. Immunolabeling showed strong Egr-1 reactivity in cell bodies in the inner nuclear and ganglion cell layers. Conclusions: Egr-1 mRNA levels in a mammalian retina show a bi-directional persistent response to opposing ocular growth stimuli. This suggests retinal Egr-1 might act as a signal for the direction of ocular growth in different species. (Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.)
Databáze:	MEDLINE
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