Theranostics 2022; 12(15):6682-6704. doi:10.7150/thno.72947 This issue

Research Paper

System-wide vitreous proteome dissection reveals impaired sheddase activity in diabetic retinopathy

Asfa Alli-Shaik1*, Beiying Qiu1,2,4*, Siew Li Lai1, Ning Cheung2,3,4, Gavin Tan2,3,4, Suat Peng Neo1, Alison Tan2,4, Chiu Ming Gemmy Cheung2,3,4, Wanjin Hong1, Tien Yin Wong2,3,5, Xiaomeng Wang1,2,4✉, Jayantha Gunaratne1,6✉

1. Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138673.
2. Singapore Eye Research Institute (SERI), Singapore 169856.
3. Singapore National Eye Centre (SNEC), Singapore 168751.
4. Centre for Vision Research, Duke-NUS Medical School, Singapore 169857.
5. Tsinghua Medicine, Tsinghua University, Beijing China 100084.
6. Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117594.
*These authors contributed equally to this work.

This is an open access article distributed under the terms of the Creative Commons Attribution License ( See for full terms and conditions.
Alli-Shaik A, Qiu B, Lai SL, Cheung N, Tan G, Neo SP, Tan A, Cheung CMG, Hong W, Wong TY, Wang X, Gunaratne J. System-wide vitreous proteome dissection reveals impaired sheddase activity in diabetic retinopathy. Theranostics 2022; 12(15):6682-6704. doi:10.7150/thno.72947. Available from

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Graphic abstract

Rationale: Diabetic retinopathy (DR) is a major complication of diabetes mellitus causing significant vision loss. DR is a multifactorial disease involving changes in retinal microvasculature and neuronal layers, and aberrations in vascular endothelial growth factors (VEGF) and inflammatory pathways. Despite the success of anti-VEGF therapy, many DR patients do not respond well to the treatment, emphasizing the involvement of other molecular players in neuronal and vascular aberrations in DR.

Methods: We employed advanced mass spectrometry-based proteome profiling to obtain a global snapshot of altered protein abundances in vitreous humor from patients with proliferative DR (PDR) in comparison to individuals with epiretinal membrane without active DR or other retinal vascular complications. Global proteome correlation map and protein-protein interaction networks were used to probe into the functional inclination of proteins and aberrated molecular networks in PDR vitreous. In addition, peptide-centric analysis of the proteome data was carried out to identify proteolytic processing, primarily ectodomain shedding events in PDR vitreous. Functional validation experiments were performed using preclinical models of ocular angiogenesis.

Results: The vitreous proteome landscape revealed distinct dysregulations in several metabolic, signaling, and immune networks in PDR. Systematic analysis of altered proteins uncovered specific impairment in ectodomain shedding of several transmembrane proteins playing critical roles in neurodegeneration and angiogenesis, pointing to defects in their regulating sheddases, particularly ADAM10, which emerged as the predominant sheddase. We confirmed that ADAM10 protease activity was reduced in animal models of ocular angiogenesis and established that activation of ADAM10 can suppress endothelial cell activation and angiogenesis. Furthermore, we identified the impaired ADAM10-AXL axis as a driver of retinal angiogenesis.

Conclusion: We demonstrate restoration of aberrant ectodomain shedding as an effective strategy for treating PDR and propose ADAM10 as an attractive therapeutic target. In all, our study uncovered impaired ectodomain shedding as a prominent feature of PDR, opening new possibilities for advancement in the DR therapeutic space.

Keywords: ADAM10, ectodomain shedding, diabetic retinopathy, sheddase, vitreous proteome