Abstract
BackgroundMüller cell gliosis occurs in various retinal pathologies regardless of the underlying cellular defect. Because activated Müller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy.Methodology/Principal FindingsWe used adeno-associated viral AAV2/6 vectors to transduce mouse retinas. The transduction pattern of AAV2/6 was investigated by studying expression of the green fluorescent protein (GFP) transgene using scanning-laser ophthalmoscopy and immuno-histochemistry. AAV2/6 vectors transduced mouse Müller glial cells aligning the retinal blood vessels. However, the transduction capacity was hindered by the inner limiting membrane (ILM) and besides Müller glial cells, several other inner retinal cell types were transduced. To obtain Müller glial cell-specific transgene expression, the cytomegalovirus (CMV) promoter was replaced by the glial fibrillary acidic protein (GFAP) promoter. Specificity and activation of the GFAP promoter was tested in a mouse model for retinal gliosis. Mice deficient for Crumbs homologue 1 (CRB1) develop gliosis after light exposure. Light exposure of Crb1−/− retinas transduced with AAV2/6-GFAP-GFP induced GFP expression restricted to activated Müller glial cells aligning retinal blood vessels.Conclusions/SignificanceOur experiments indicate that AAV2 vectors carrying the GFAP promoter are a promising tool for specific expression of transgenes in activated glial cells.
Highlights
Muller glial cells are the predominant glial cell type of the vertebrate retina
Our results showed that AAV2/6 vectors were able to transduce mouse Muller glial cells aligning retinal blood vessels
Transduced Muller glial cells started to express the green fluorescent protein (GFP) transgene when activated by ciliary neurotrophic factor (CNTF) or injury. These results suggest that AAV2/6 vectors carrying the glial fibrillary acidic protein (GFAP) promoter to drive the expression of neuroprotective or anti-angiogenic factors might be a promising tool to treat retinal disorders
Summary
Muller glial cells span the entire thickness of the retina and are involved in a wide variety of physiological processes that are vital to proper functioning of the retinal neurons. They are important in retinal development, provide their neighboring neurons with metabolic support, maintain retinal ion and water homeostasis, contribute to the recycling of neurotransmitters as well as photopigments and protect the neurons against oxidative stress [1]. The dedifferentiated state of activated Muller glial cells contributes to neuronal stress due to impairment of their neurosupportive activities [4] Because of their crucial role in retinal disease, Muller glial cells are important targets for gene therapy [5]. Because activated Muller glial cells span the entire retina and align areas of injury, they are ideal targets for therapeutic strategies, including gene therapy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
