Functional and Molecular Characterization ofEx VivoCultured Epiretinal Membrane Cells from Human Proliferative Diabetic Retinopathy

Abstract

Characterization of the cell surface marker phenotype of ex vivo cultured cells growing out of human fibrovascular epiretinal membranes (fvERMs) from proliferative diabetic retinopathy (PDR) can give insight into their function in immunity, angiogenesis, and retinal detachment. FvERMs from uneventful vitrectomies due to PDR were cultured adherently ex vivo. Surface marker analysis, release of immunity- and angiogenesis-pathway-related factors upon TNFα activation and measurement of the intracellular calcium dynamics upon mechano-stimulation using fluorescent dye Fura-2 were all performed. FvERMs formed proliferating cell monolayers when cultured ex vivo, which were negative for endothelial cell markers (CD31, VEGFR2), partially positive for hematopoietic- (CD34, CD47) and mesenchymal stem cell markers (CD73, CD90/Thy-1, and PDGFRβ), and negative for CD105. CD146/MCAM and CD166/ALCAM, previously unreported in cells from fvERMs, were also expressed. Secretion of 11 angiogenesis-related factors (DPPIV/CD26, EG-VEGF/PK1, ET-1, IGFBP-2 and 3, IL-8/CXCL8, MCP-1/CCL2, MMP-9, PTX3/TSG-14, Serpin E1/PAI-1, Serpin F1/PEDF, TIMP-1, and TSP-1) were detected upon TNFα activation of fvERM cells. Mechano-stimulation of these cells induced intracellular calcium propagation representing functional viability and role of these cells in tractional retinal detachment, thus serving as a model for studying tractional forces present in fvERMs in PDR ex vivo.

Inhibition of Aberrant IGF-I Signaling in Diabetic Male Rat Retina Prevents and Reverses Changes of Diabetic Retinopathy

“…The role of IAP in mediating diabetic retinopathy has received minimal analysis. One study showed that epiretinal membranes isolated from patients with proliferative retinopathy and maintained in culture contained cells that when exposed to high glucose increased their expression IAP and VEGFR2 further suggesting that IAP may be involved in the pathogenesis of this condition [43]. Thrombospondin-2 (TSP-2) is a protein that binds directly to IAP and enhances IAP-mediated cellular responses [44].…”

Interplay of endothelial-mesenchymal transition, inflammation, and autophagy in proliferative diabetic retinopathy pathogenesis

“…The transcriptome analyses were largely in line with the abovementioned trends, and the protein expression in the vitreous humor confirmed those tendencies. It is well established that angiogenesis and fibrous proliferation are critical features of PDR, which can eventually lead to severe visual impairment [ 15 , 16 ]. On the one hand, the complex process of angiogenesis during PDR involves remodeling the vascular endothelial extracellular matrix, degradation of the basement membrane, and enhancement of endothelial cell invasion/migration [ 17 ], culminating in the formation of immature capillaries.…”

Involvement of the Purinergic System in Cell Death in Models of Retinopathies

“…When it comes to cell death, the adenosine A2A receptor plays a role [17]. It has already been seen that blocking the A2A receptor controls microglial reactivity [18], delays excitotoxic death of embryonic motor neurons in vitro [19], and is able to prevent cell death in ischemic retinas [20]. This evidence makes it clear that this receptor is of great interest when it comes to therapeutic targets to improve the condition of various diseases in the retina and nervous system.…”