The microRNA-7-mediated reduction in EPAC-1 contributes to vascular endothelial permeability and eNOS uncoupling in murine experimental retinopathy
Aims: To investigate the consequences of oxidative stress and hypoxia on EPAC-1 expression during retinopathy. Methods: Oxygen-induced retinopathy was induced in mice and EPAC-1 expression investigated by immunofluorescence. In silico analyses were used to identify a link between EPAC-1 expression a...
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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
2017
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| In: |
Acta diabetologica
Year: 2017, Volume: 54, Issue: 6, Pages: 581-591 |
| ISSN: | 1432-5233 |
| DOI: | 10.1007/s00592-017-0985-y |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1007/s00592-017-0985-y Verlag, Volltext: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429352/ 
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| Author Notes: | Veronica Garcia-Morales, Julian Friedrich, Lysanne M. Jorna, Manuel Campos-Toimil, Hans-Peter Hammes, Martina Schmidt, Guido Krenning |
| Summary: | Aims: To investigate the consequences of oxidative stress and hypoxia on EPAC-1 expression during retinopathy. Methods: Oxygen-induced retinopathy was induced in mice and EPAC-1 expression investigated by immunofluorescence. In silico analyses were used to identify a link between EPAC-1 expression and microRNA-7-5p in endothelial cells and confirmed by western blot analyses on cells expressing microRNA-7-5p. In vitro, endothelial cells were either incubated at 2% oxygen or transfected with microRNA-7-5p, and the effects of these treatments on EPAC-1 expression, endothelial hyperpermeability and NO production were assessed. In the Ins2Akita mouse model, levels of EPAC-1 expression as well as microRNA-7-5p were assessed by qPCR. Endothelial nitric oxide synthase was assessed by immunoblotting in the Ins2Akita model. Results: Hypoxia induces the expression of microRNA-7-5p that translationally inhibits the expression of EPAC-1 in endothelial cells, resulting in hyperpermeability and the loss of eNOS activity. Activation of EPAC-1 by the cAMP analogue 8-pCPT-2′-O-Me-cAMP reduced the sensitivity of EPAC-1 to oxidative stress and restored the endothelial permeability to baseline levels. Additionally, 8-pCPT-2′-O-Me-cAMP rescued eNOS activity and NO production. In mouse models of retinopathy, i.e., oxygen-induced retinopathy and the spontaneous diabetic heterozygous Ins2Akita mice, EPAC-1 levels are decreased which is associated with an increase in microRNA-7-5p expression and reduced eNOS activity. Conclusion/Interpretation: In retinopathy, EPAC-1 expression is decreased in a microRNA-7-mediated manner, contributing to endothelial dysfunction. Pharmacological activation of remnant EPAC-1 rescues endothelial function. Collectively, these data indicate that EPAC-1 resembles an efficacious and druggable target molecule for the amelioration of (diabetic) retinopathy. Electronic supplementary material. The online version of this article (doi:10.1007/s00592-017-0985-y) contains supplementary material, which is available to authorized users. |
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| Item Description: | Published online: 28 March 2017 Gesehen am 21.06.2018 DOI eventuell nicht korrekt |
| Physical Description: | Online Resource |
| ISSN: | 1432-5233 |
| DOI: | 10.1007/s00592-017-0985-y |