Anu A Thomas1, Saumik Biswas1, Biao Feng1, Shali Chen1, John Gonder2, Subrata Chakrabarti3. 1. Department of Pathology and Laboratory Medicine, Western University, Dental Science Building 4033, 1151 Richmond Street, London, ON, N6A 5C1, Canada. 2. Department of Ophthalmology, Western University, London, ON, Canada. 3. Department of Pathology and Laboratory Medicine, Western University, Dental Science Building 4033, 1151 Richmond Street, London, ON, N6A 5C1, Canada. subrata.chakrabarti@lhsc.on.ca.
Abstract
AIMS/HYPOTHESIS: The pathophysiology of diabetic retinopathy is linked to hyperglycaemia and its effect on retinal microvascular tissues. The resulting endothelial injury changes the endothelial cell phenotype to acquire mesenchymal properties (i.e. endothelial-mesenchymal transition [EndMT]). Such changes can be regulated by epigenetic mechanisms, including long non-coding RNAs (lncRNAs). lncRNA H19 may influence EndMT through TGF-β. We investigated the role of H19 in regulating EndMT during diabetic retinopathy. METHODS: H19 was overexpressed or silenced in human retinal endothelial cells exposed to various glucose levels. The cells were examined for H19, endothelial and mesenchymal markers. We then expanded the study to retinal tissues in a mouse model of diabetic retinopathy and also examined vitreous humour samples from individuals with proliferative diabetic retinopathy. RESULTS: Expression of H19 was downregulated in high glucose conditions (25 mmol/l). H19 overexpression prevented glucose-induced EndMT. Such changes appear to involve TGF-β through a Smad-independent mechanism. Diabetes caused downregulation of retinal H19. Using H19 knockout mice, we demonstrated similar EndMT in the retina. Examination of vitreous humour from individuals with proliferative diabetic retinopathy also reinforced the downregulation of H19 in diabetes. CONCLUSIONS/ INTERPRETATION: We therefore concluded that H19 regulates EndMT in diabetic retinopathy through specific mechanisms. DATA AVAILABILITY: The results from our previous microarray can be found online using the GEO accession number GSE122189.
AIMS/HYPOTHESIS: The pathophysiology of diabetic retinopathy is linked to hyperglycaemia and its effect on retinal microvascular tissues. The resulting endothelial injury changes the endothelial cell phenotype to acquire mesenchymal properties (i.e. endothelial-mesenchymal transition [EndMT]). Such changes can be regulated by epigenetic mechanisms, including long non-coding RNAs (lncRNAs). lncRNA H19 may influence EndMT through TGF-β. We investigated the role of H19 in regulating EndMT during diabetic retinopathy. METHODS:H19 was overexpressed or silenced in human retinal endothelial cells exposed to various glucose levels. The cells were examined for H19, endothelial and mesenchymal markers. We then expanded the study to retinal tissues in a mouse model of diabetic retinopathy and also examined vitreous humour samples from individuals with proliferative diabetic retinopathy. RESULTS: Expression of H19 was downregulated in high glucose conditions (25 mmol/l). H19 overexpression prevented glucose-induced EndMT. Such changes appear to involve TGF-β through a Smad-independent mechanism. Diabetes caused downregulation of retinal H19. Using H19 knockout mice, we demonstrated similar EndMT in the retina. Examination of vitreous humour from individuals with proliferative diabetic retinopathy also reinforced the downregulation of H19 in diabetes. CONCLUSIONS/ INTERPRETATION: We therefore concluded that H19 regulates EndMT in diabetic retinopathy through specific mechanisms. DATA AVAILABILITY: The results from our previous microarray can be found online using the GEO accession number GSE122189.
Authors: Roberta Giordo; Yusra M A Ahmed; Hilda Allam; Salah Abusnana; Lucia Pappalardo; Gheyath K Nasrallah; Arduino Aleksander Mangoni; Gianfranco Pintus Journal: Front Cell Dev Biol Date: 2021-05-19