Scientific publications
Evaluation of Macular Retinal Vessels and Histological Changes in Two Cases of COVID-19. Scientific Publication
Maria Hernandez 1 2 3 , Jorge González-Zamora 1 , Sergio Recalde 1 2 3 , Maite Moreno-Orduña 1 2 , Valentina Bilbao-Malavé 1 , Manuel Saenz de Viteri 1 2 3 , Manuel F Landecho 4 5 , Patricia Fernandez-Robredo 1 2 3 , Alfredo García-Layana 1 2 3
Abstract
The purpose of this study was to assess vascular and histological alterations in two COVID-19 and three control post-mortem retinas.
The macular areas of flat-mounted samples were processed for immunofluorescence. Lectin and collagen IV positive vessels were captured under confocal microscopy, and endothelium loss and tortuosity were analyzed.
Expression of ACE2 (angiotensin-converting enzyme 2) (the receptor for SARS-CoV-2), Iba1 (ionized calcium-binding adaptor molecule 1) and GFAP (glial fibrillary acidic protein) were quantified in retinal sections.
The number of lectin vessels in COVID-19 retinas decreased by 27% compared to the control (p < 0.01) and the tortuosity increased in COVID-19 retinas (7.3 ± 0.2) vs. control retinas (6.8 ± 0.07) (p < 0.05). Immunofluorescence analysis revealed an increase in ACE2 (2.3 ± 1.3 vs. 1.0 ± 0.1; p < 0.0001) and Iba1 expression (3.06 ± 0.6 vs. 1.0 ± 0.1; p < 0.01) in COVID-19 sections whereas no changes in GFAP were observed.
Analysis of the COVID-19 macular retinal tissue suggested that endothelial cells are a preferential target of SARS-CoV-2 with subsequent changes through their ACE2 receptor expression and morphology. Thus, microglial activation was hyperactive when facing an ensuing immunological challenge after SARS-CoV-2 infection.
CITATION Biomedicines. 2021 Oct 26;9(11):1546. doi: 10.3390/biomedicines9111546
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