Functional connexin35 increased in the myopic chicken retina.

Seema Banerjee,Feng Pan,King Kit Li,George Tang,Qing Wang,Chi-Wai Do,Chunghim So,Sze Wan Shan

doi:10.1017/s0952523821000079

Seema Banerjee, Feng Pan + Show 6 more

Open Access

https://doi.org/10.1017/s0952523821000079

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Abstract

Our previous research showed that increased phosphorylation of connexin (Cx)36 indicated extended coupling of AII amacrine cells (ACs) in the rod-dominant mouse myopic retina. This research will determine whether phosphorylation at serine 276 of Cx35-containing gap junctions increased in the myopic chicken, whose retina is cone-dominant. Refractive errors and ocular biometric dimensions of 7-days-old chickens were determined following 12h and 7days induction of myopia by a -10D lens. The expression pattern and size of Cx35-positive plaques were examined in the early (12h) and compensated stages (7days) of lens-induced myopia (LIM). At the same time, phosphorylation at serine 276 (functional assay) of Cx35 in strata 5 (S5) of the inner plexiform layer was investigated. The axial length of the 7days LIM eyes was significantly longer than that of non-LIM controls (P<0.05). Anti-phospho-Ser276 (Ser276-P)-labeled plaques were significantly increased in LIM retinas at both 12h and 7days. The density of Ser276-P of Cx35 was observed to increase after 12h LIM. In the meanwhile, the areas of existing Cx35 plaques did not change. As there was more phosphorylation of connexin35 at Ser276 at both the early and late stages (12h) and 7days of LIM chicken retinal activity, the coupling with ACs could be increased in myopia development of the cone-dominated chicken retina.

Highlights

Myopia or nearsightedness is the most common refractive error and usually results from excess axial elongation
It was reported that the phosphorylation state of Ser293, indicative of the function of coupling through Cx36 gap junctions affected by the dopamine pathway, increased in the myopic mouse retina (Banerjee et al, 2020) during refractive development and may be involved in the development of human myopia
Seven days lens-induced myopia (LIM) and measurement of refractive errors in chicken eye Retinoscopy revealed that the refractive errors after 7 days LIM and control chicken were À10.1 Æ 0.9 D and +2.8 Æ 0.9 D, respectively (Fig. 1A)

Summary

Introduction

Myopia or nearsightedness is the most common refractive error and usually results from excess axial elongation. A possible strategy in reaction to the myopic mouse retina’s noisy signaling status is to increase functional gap junction coupling of AII ACs. It was reported that the phosphorylation state of Ser293, indicative of the function of coupling through Cx36 gap junctions affected by the dopamine pathway, increased in the myopic mouse retina (Banerjee et al, 2020) during refractive development and may be involved in the development of human myopia. Cx35/36 phosphorylation leads to an increasing gap junction coupling between AII ACs in the myopic mouse retina (Banerjee et al, 2020). These results support our hypothesis that Cx35/36 function regulation is critical to understand the visual signaling processes in both normal and myopic retinas

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Results

Discussion

Limitations of the study