Association between anti‐fibrillin‐2 protein induced retinal degeneration via intravitreous delivery and activated TGF‐β signalling in mice

Abstract

Fibrillin‐2 (FBN2) is a major component of tissue microfibrils, and the decrease of FBN2 perturbs the signalling events mediated by transforming growth factor‐β (TGF‐β), thereby playing a role in macular degeneration. However, the association between the retinal degeneration resulting from the abnormality of FBN2 and the activation of TGF‐β signalling has not been fully addressed. In the present study, the mice were divided into a normal control group (NC group), a phosphate‐buffered saline (PBS) injection group (PBS group), and an anti‐FBN2 protein injection group (anti‐FBN2 group), and the mice in PBS and anti‐FBN2 groups received the relevant treatment via the intravitreal injection once a week for three consecutive weeks. One week later after injection, the retinal morphology and visual function of the fundus were detected. Further, the expression of FBN2, TGF‐β1, TGF‐β2 and TGF‐β3 in retina was measured using quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay (ELISA), respectively. As a result, fundus examination suggests that after intravitreous injection of anti‐FBN2 protein, there were a large patchy yellow white degeneration region and numerous pigmentations in the retina in anti‐FBN2‐treated mice; by contrast, there was no apparent change in mice from the NC and PBS groups. The retina suffered markedly damage, and the thickness of whole retina and outer nuclear layer markedly thinned. The expression of FBN2 was decreased whereas the levels of TGF‐β1, TGF‐β2 and TGF‐β3 were upregulated. Together, our findings indicate that the intravitreous delivery of anti‐FBN2 protein could induce retina degeneration in mice, accompanied by the higher activated TGF‐β. The retinal degeneration mouse model established will provide a platform for the investigation of the retinal diseases.

Intravitreal injection of fibrillin 2 (Fbn2) recombinant protein for therapy of retinopathy in a retina-specific Fbn2 knock-down mouse model

“…A non-synonymous variant of the FBN2 gene, rs154001 (p.Val965Ile), was identified to be associated with AMD, and the non-synonymous variants of the FBN2 gene, including c.3430G-A (p. Glu1144Lys), c.3740T-C(p.Met1247Thr), c.4312G > A(p.Glu1438Lys) and c.4141C > A (p.His1381Asn) were identified in patients with EOMD 1 . It has been reported that the FBN2 protein is located in Bruch's membrane, that it is reduced in AMD eyes, and that a reduction in the expression of fbn2 in the retina was associated with the development of a retinopathy in mice 1 , 7 . Recombinant proteins have been considered to be therapeutic agents for the treatment of inherited diseases, however, their clinical application has been limited due to their inability to enter the targeted cells and to be functional in the intracellular site.…”

“…The experimental study included adult C57BL/6J male mice with an age of 8 weeks and a body weight of 22–23 g (supplied by Beijing Vital River Experimental Animal Technology Co. Ltd., Beijing, China.) 7 . The Ethics committee of the Eye Institute of the Shandong University of Traditional Chinese Medicine approved the study and confirmed that its design was in accordance with ARVO (Association for Vision and Eye Research) statement for the use of Ophthalmic and Visual Research.…”