Abstract
Purpose :
This study aimed to investigate the impact of eliminating 12/15-Lipoxygease (12/15-LO)
on retinal structure and function in diabetic mice and the underlying mechanism, particularly
exploring the role of epigenetic modification and cellular metabolic shifts.
Methods :
Akita mice, a model of type 1 diabetes, were crossbred with 12/15-LO knockout mice.
Retinal function was assessed using electroretinography (ERG), and liquid chromatography-
mass spectrometry (LC/MS) measured retinal 12- and 15-HETEs. Retinal sections were stained
with Hematoxylin and Eosin for structural analysis, including thickness measurement, and Neun
for assessing neuronal cell death. A microRNA array was employed to evaluate epigenetic
modifications in both wild-type and 12/15-LO knockout diabetic mice. Ex vivo experiments with
retinal explants assessed the direct effects of 12-hydroxyeicosatetraenoic acid (12-HETE, 1 μM)
on various parameters, including glial fibrillary acidic protein (GFAP), NeuN expression, and
cellular metabolism using a Seahorse XF Analyzer, in comparison to control.
Results :
Deletion of 12/15-LO notably reduced retinal 12-HETE levels. Preservation of retinal
thickness, function, and brn3 expression was observed in diabetic mice lacking 12/15-LO.
Restoration of specific microRNAs (miRs) and differential expression patterns were noted with
12/15-LO deletion. While diabetes dysregulated several miRs, many of them were restored by
12/15-LO deletion. Among these miRs, only four of the decreased miRs in diabetes were
significantly restored in 12/15-LO knockout mice (miR-431-5p, miR-7003-5p, miR-1930-5p, and
let-7a-1). Conversely, out of the increased miRs in diabetic mice, only 15 were significantly
restored by the deletion of 12/15-LO (e.g. miR-6413 and miR-466). Interestingly, 12-HETE
induced significant alterations in neuronal cells and glial morphology within retinal explants. The
treatment induced a simultaneous increase in oxygen consumption rate (OCR) and extracellular
acidification rate (ECAR), suggesting potential mitochondrial dysfunction. Additionally, 12-HETE
increased calcium signaling in retinal explants.
Conclusions :
12/15-LO plays crucial role in inducing retinal neuronal dysfunction during DR via
epigenetic modifications and cellular metabolic shifts which reflects mitochondrial dysfunction.
12/15-LO is a potential therapeutic target in DR.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.