Disrupting VE-cadherin Y685 phosphorylation inhibits development of experimental diabetic and prediabetic retinopathy
Yixin Wang, Hongpeng Huang, Feng Shao, Rachana Eshwaran, Miao Qin, Noor Karim, Yonggang Ren, Gergana Dobreva, Hans-Peter Hammes, Thomas Wieland, Yuxi Feng
Yixin Wang, Hongpeng Huang, Feng Shao, Rachana Eshwaran, Miao Qin, Noor Karim, Yonggang Ren, Gergana Dobreva, Hans-Peter Hammes, Thomas Wieland, Yuxi Feng
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Research Article Endocrinology Metabolism Ophthalmology

Disrupting VE-cadherin Y685 phosphorylation inhibits development of experimental diabetic and prediabetic retinopathy

Abstract

Diabetic retinopathy involves early retinal vascular barrier breakdown and pericyte loss, yet the initiating molecular events remain poorly defined. Vascular endothelial cadherin (VE-cadherin), a key regulator of endothelial integrity, is notably reduced in diabetic and prediabetic nucleoside diphosphate kinase B–deficient (NDPKB-deficient) mouse retinas, particularly in the retinal deep capillary layer, and this decline precedes pericyte loss. In vitro, high glucose (HG) and NDPKB deficiency induced VE-cadherin Y685 phosphorylation, promoting its junctional internalization, activating the hexosamine biosynthesis pathway, and increasing angiopoietin 2 (Ang2), resulting in impaired endothelial barrier function and disrupting pericyte attachment. Preventing Y685 phosphorylation through VE-cadherin Y685F mutation blocked these HG- and NDPKB-driven pathological effects. Pharmacological intervention experiments identified protein O-linked β-N-acetyl glucosamine (O-GlcNAc) modification as a mediator of Y685-dependent Ang2 upregulation. In vivo, VE-cadherin Y685F-knockin mice were protected from diabetes- and prediabetes-induced vascular hyperpermeability, exhibited reduced protein O-GlcNAcylation and Ang2 induction, and maintained neuronal function. O-GlcNAc–enriched retinal proteomics further showed that the Y685F mutation restored balanced neurovascular and mitochondrial pathways. These findings highlight the potential of targeting VE-cadherin Y685 phosphorylation as a promising therapeutic approach to maintain retinal vascular integrity and attenuate the pathological progression of diabetic and prediabetic retinopathy.

Authors

Yixin Wang, Hongpeng Huang, Feng Shao, Rachana Eshwaran, Miao Qin, Noor Karim, Yonggang Ren, Gergana Dobreva, Hans-Peter Hammes, Thomas Wieland, Yuxi Feng

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Figure 1

VE-cadherin expression is reduced in the diabetic and prediabetic retinas.

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VE-cadherin expression is reduced in the diabetic and prediabetic retina...
(A) VE-cadherin expression was detected in the retinas of 6-week-old Ins2Akita and control mice by immunoblotting. n = 3. (B) VE-cadherin expression in the retinas of NDPKB–/– and WT mice of different ages (1, 3, 4, and 5 months) was determined using immunoblotting analysis. (C) Quantification of Western blot data. n = 3. (D) Retinal deep capillary layers were visualized with lectin (red) and VE-cadherin (green). n = 3. (E) HUVECs were transfected with either NDPKB siRNA or scrambled siRNA and stimulated with either NG (5.5 mM) or HG (30 mM). Gβ serves as a housekeeping marker on the cell membrane. n = 3. Overall P = 0.0119. (F) HUVECs were stained with VE-cadherin (green) to show cellular VE-cadherin distribution. Arrows show the linear changes, and membrane VE-cadherin expression was quantified. n = 3. Overall P < 0.001. (G) NDPKB knockdown efficiency was detected. n = 3. Overall P < 0.001. (H) Staining and quantification of internalized VE-cadherin in NDPKB-depleted HUVECs stimulated with HG. n = 6, repeated 3 times. Overall P = 0.0432. WT, wild-type mice; NDPKB–/–, NDPKB homozygous mice; NG, normal glucose; HG, high glucose; sicon, control siRNA; siNDPKB, NDPKB siRNA. *P < 0.05, **P < 0.01, ***P < 0.001. Statistical significance was determined using an unpaired 2-tailed t test (A, C, and D), or 1-way ANOVA with Tukey’s post hoc test for multiple comparisons (E–H). Scale bar: 50 μm.