Abstract
Purpose :
We propose to identify mechanisms that underlie the initiation and early progression of diabetic retinopathy (DR) via dissecting the genes and pathways controlling diabetes-induced responses in Müller glial cells (MG), which are one of the first responders of diabetes in the retina. In our studies, we discovered zinc finger protein 36 (ZFP36) are significantly altered by diabetes and contribute to the development of DR.
Methods :
Streptozotocin (STZ)-induced diabetic rats were used as models to study DR. RNA-seq, histological immunostaining and fluorescence mRNA in situ hybridization (FISH) were utilized to capture diabetes-induced transcriptomic changes in the retinal MG at early stages. Endogenous ZFP36 gene expression was detected and quantified by quantitative single molecule FISH (smFISH) on rat MG. We also developed novel adeno-associated virus (AAVs) that can specifically and efficiently label and manipulate MG in vivo in rat retinas. These AAVs were used to knock down or overexpress ZFP36 in rat MG in vivo under normal and diabetic conditions. The DR-related retinal phenotypes were characterized as described in the literature, including MG gliosis, RGC survival rate, and vascular permeability and neovascularization.
Results :
We detected increased ZFP36 expression in MG starting from 1 month after STZ injection in rats compared to WT controls. The upregulation of ZFP36 diminished at around 3 months after STZ injection. Knocking down ZFP36 in rat MG in vivo using AAVs resulted in accelerated development of DR in diabetic rats, while over-expression can delay the development of the disease.
Conclusions :
Diabetes-induced upregulation of ZFP36 in MG plays a beneficial role, and failure to maintain ZFP36 levels contributes to the initiation and early progression of DR.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.