N-cadherin expression in a rat model of retinal detachment and reattachment.
OBJECTIVE
To observe the changes in N-cadherin expression in the retina after experimental retinal detachment (RD) and reattachment in the rat and to explore the role N-cadherin might play after RD.


METHODS
Forty rat retinas were detached by transscleral injection of 1.4% sodium hyaluronate into the subretinal space. The eyes were enucleated at different time intervals (n = 5), followed by fixation, embedding, and sectioning. The differences in N-cadherin expression in the normal retina, detached retina, and spontaneously reattached retina were determined. Furthermore, an N-cadherin antagonist was injected in combination with 1.4% sodium hyaluronate into the subretinal space in another 10 eyes, in an attempt to demonstrate the role N-cadherin plays after RD.


RESULTS
N-cadherin was not expressed in the RPE layer of the normal rat retina. After RD, intense immunolabeling of N-cadherin was seen in the RPE cells, the photoreceptors, and the outer limiting membrane (OLM). An increasing number of cytokeratin (CK)-positive cells likely to be RPE cells was found attached to the outer surface of the detached neural retina. Where the retina was reattached, the N-cadherin immunolabeling rapidly decreased. In eyes treated with an N-cadherin antagonist, the retinas appeared thinner than that in eyes without treatment, and the photoreceptor nuclei showed significantly loss. Moreover, CK-positive cells attached to the outer surface of the detached retina were markedly fewer in number.


CONCLUSIONS
Increased expression of N-cadherin in the RPE cells, the photoreceptor cells, and the OLM of the retina after RD may contribute to RPE cell migration and photoreceptor survival. These changes could be reversed by retinal reattachment.
Chen
Hui-Jin
HJ
Department of Ophthalmology, Peking University Third Hospital, No. 49 Hua Yuan Bei Lu, Haidian District, 100083 Beijing, China.
Ma
Zhi-Zhong
ZZ
D000818:Animals; D016570:Bruch Membrane / Q000378:metabolism; D015820:Cadherins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D007633:Keratins / Q000378:metabolism; D008297:Male; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012163:Retinal Detachment / Q000378:metabolism*
D015820:Cadherins; D007633:Keratins