scholarly journals AAV Induced Expression of Human Rod and Cone Opsin in Bipolar Cells of a Mouse Model of Retinal Degeneration

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Michelle E. McClements ◽  
Federica Staurenghi ◽  
Meike Visel ◽  
John G. Flannery ◽  
Robert E. MacLaren ◽  
...  

Vision loss caused by inherited retinal degeneration affects millions of people worldwide, and clinical trials involving gene supplementation strategies are ongoing for select forms of the disease. When early therapeutic intervention is not possible and patients suffer complete loss of their photoreceptor cells, there is an opportunity for vision restoration techniques, including optogenetic therapy. This therapy provides expression of light-sensitive molecules to surviving cell types of the retina, enabling light perception through residual neuronal pathways. To this end, the bipolar cells make an obvious optogenetic target to enable upstream processing of visual signal in the retina. However, while AAV transduction of the bipolar cells has been described, the expression of human opsins in these cell types within a model of retinal degeneration (rd1) has been less successful. In this study, we have expanded the optogenetic toolkit and shown successful expression of human rhodopsin driven by an ON-bipolar cell promoter (Grm6) in the rd1 mouse model using modified AAV capsids (AAV2.4YF, AAV8.BP2, and AAV2.7m8) delivered via intraocular injection. We also show the first presentation of ectopic expression of human cone opsin in the bipolar cells of rd1 mice. These data provide evidence of an expansion of the optogenetic toolkit with the potential to restore useful visual function, setting the stage for future trials in human patients.

1994 ◽  
Vol 11 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Elena V. Grigorenko ◽  
Hermes H. Yeh

AbstractThis study profiled the expression of the family of GABAA receptor β-subunits in the adult rat retina. Using a combination of reverse transcriptase reaction followed by polymerase chain reaction (RT-PCR) with gene-specific primers, the expression of mRNAs encoding the β1, β2, and β3 subunits was first examined in the intact retina and then in separated retinal nuclear layers. However, it was found that a critical analysis. had to be carried out at the level of the single cell in order to resolve the differential patterns of expression among the retinal cell types. When cells were isolated and identified following acute dissociation, RT-PCR revealed that individual rod photoreceptor cells expressed consistently the β1 and β2 messages while the bipolar cells expressed the β1 and β3 messages. Ganglion cells displayed considerable variability in β-subunit expression, perhaps reflecting their functional and morphological heterogeneity in the retina. In contrast, the nonneuronal Mueller cells did not express any of the β-subunit messages. These results indicate that the expression of GABAA receptor subunits is cell-type dependent. Furthermore, as the expression of other families of GABAA receptor subunits are profiled and the patterns of subunit assembly are better understood, our results raise the possibility that GABAA receptors with different subunit compositions can be expected to be coexpressed within a single retinal neuron.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yevgeniya Atiskova ◽  
Susanne Bartsch ◽  
Tatyana Danyukova ◽  
Elke Becker ◽  
Christian Hagel ◽  
...  

Abstract Neuronal ceroid lipofuscinosis (NCL) type 1 (CLN1) is a neurodegenerative storage disorder caused by mutations in the gene encoding the lysosomal enzyme palmitoyl-protein thioesterase 1 (PPT1). CLN1 patients suffer from brain atrophy, mental and motor retardation, seizures, and retinal degeneration ultimately resulting in blindness. Here, we performed an in-depth analysis of the retinal phenotype of a PPT1-deficient mouse, an animal model of this condition. Reactive astrogliosis and microgliosis were evident in mutant retinas prior to the onset of retinal cell loss. Progressive accumulation of storage material, a pronounced dysregulation of various lysosomal proteins, and accumulation of sequestosome/p62-positive aggregates in the inner nuclear layer also preceded retinal degeneration. At advanced stages of the disease, the mutant retina was characterized by a significant loss of ganglion cells, rod and cone photoreceptor cells, and rod and cone bipolar cells. Results demonstrate that PPT1 dysfunction results in early-onset pathological alterations in the mutant retina, followed by a progressive degeneration of various retinal cell types at relatively late stages of the disease. Data will serve as a reference for future work aimed at developing therapeutic strategies for the treatment of retinal degeneration in CLN1 disease.


2016 ◽  
Vol 44 (5) ◽  
pp. 1245-1251 ◽  
Author(s):  
David A. Parfitt ◽  
Amelia Lane ◽  
Conor Ramsden ◽  
Katarina Jovanovic ◽  
Peter J. Coffey ◽  
...  

The photoreceptor cells in the retina have a highly specialised sensory cilium, the outer segment (OS), which is important for detecting light. Mutations in cilia-related genes often result in retinal degeneration. The ability to reprogramme human cells into induced pluripotent stem cells and then differentiate them into a wide range of different cell types has revolutionised our ability to study human disease. To date, however, the challenge of producing fully differentiated photoreceptors in vitro has limited the application of this technology in studying retinal degeneration. In this review, we will discuss recent advances in stem cell technology and photoreceptor differentiation. In particular, the development of photoreceptors with rudimentary OS that can be used to understand disease mechanisms and as an important model to test potential new therapies for inherited retinal ciliopathies.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 913
Author(s):  
Ander Anasagasti ◽  
Araceli Lara-López ◽  
Santiago Milla-Navarro ◽  
Leire Escudero-Arrarás ◽  
María Rodríguez-Hidalgo ◽  
...  

Inherited retinal dystrophies (IRDs) are a group of rare retinal conditions, including retinitis pigmentosa (RP), caused by monogenic mutations in 1 out of more than 250 genes. Despite recent advancements in gene therapy, there is still a lack of an effective treatment for this group of retinal conditions. MicroRNAs (miRNAs) are a class of highly conserved small non-coding RNAs that inhibit gene expression. Control of miRNAs-mediated protein expression has been described as a widely used mechanism for post-transcriptional regulation in many physiological and pathological processes in different organs, including the retina. Our main purpose was to test the hypothesis that modulation of a group of miRNAs can protect photoreceptor cells from death in the rd10 mouse model of retinitis pigmentosa. For this, we incorporated modulators of three miRNAs in adeno-associated viruses (AAVs), which were administered through sub-retinal injections. The results obtained indicate that inhibition of the miR-6937-5p slows down the visual deterioration of rd10 mice, reflected by an increased electroretinogram (ERG) wave response under scotopic conditions and significant preservation of the outer nuclear layer thickness. This work contributes to broadening our knowledge on the molecular mechanisms underlying retinitis pigmentosa and supports the development of novel therapeutic approaches for RP based on miRNA modulation.


Gene Therapy ◽  
2021 ◽  
Author(s):  
Matthew R. Cring ◽  
Kacie J. Meyer ◽  
Charles C. Searby ◽  
Adam Hedberg-Buenz ◽  
Michael Cave ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kolja Becker ◽  
Holger Klein ◽  
Eric Simon ◽  
Coralie Viollet ◽  
Christian Haslinger ◽  
...  

AbstractDiabetic Retinopathy (DR) is among the major global causes for vision loss. With the rise in diabetes prevalence, an increase in DR incidence is expected. Current understanding of both the molecular etiology and pathways involved in the initiation and progression of DR is limited. Via RNA-Sequencing, we analyzed mRNA and miRNA expression profiles of 80 human post-mortem retinal samples from 43 patients diagnosed with various stages of DR. We found differentially expressed transcripts to be predominantly associated with late stage DR and pathways such as hippo and gap junction signaling. A multivariate regression model identified transcripts with progressive changes throughout disease stages, which in turn displayed significant overlap with sphingolipid and cGMP–PKG signaling. Combined analysis of miRNA and mRNA expression further uncovered disease-relevant miRNA/mRNA associations as potential mechanisms of post-transcriptional regulation. Finally, integrating human retinal single cell RNA-Sequencing data revealed a continuous loss of retinal ganglion cells, and Müller cell mediated changes in histidine and β-alanine signaling. While previously considered primarily a vascular disease, attention in DR has shifted to additional mechanisms and cell-types. Our findings offer an unprecedented and unbiased insight into molecular pathways and cell-specific changes in the development of DR, and provide potential avenues for future therapeutic intervention.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1033
Author(s):  
Lorena Olivares-González ◽  
Sheyla Velasco ◽  
Isabel Campillo ◽  
David Salom ◽  
Emilio González-García ◽  
...  

Background: Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. Methods: NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. Results: NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. Conclusions: NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A828-A828
Author(s):  
Kevinn Eddy ◽  
Christina Marinaro ◽  
Maryam Rasheed ◽  
Joseph Campagnolo ◽  
Xiaoxuan Zhong ◽  
...  

BackgroundMuch progress has been made in understanding melanoma pathogenesis within the last few years through targeted therapies and immunotherapies. However, resistance to small molecule inhibitors remains an obstacle. Immunotherapies such as checkpoint inhibitors against PD-1/PD-L1 lead to durable responses but only in a subset of melanoma patients. Mouse models reflecting human cancers provide invaluable tools towards the translation of basic science discoveries to clinical therapies, but many of these in vivo studies are short-term and do not accurately mimic patient circumstances. Our lab has a melanoma-prone transgenic mouse model which is driven by ectopic expression of a normal neuronal receptor, metabotropic glutamate receptor 1 (GRM1). This mouse model recapitulates melanoma development and progression frequently associated with melanoma patients, where aberrant GRM1 expression is detected. We have shown that in >90% of late-stage melanoma patients, there is atypical GRM1 mediated signaling and expression.MethodsIn this study, we are using these mice, TGS, to determine the long-term, 18-week, therapeutic consequences of troriluzole, a prodrug for riluzole, which is an inhibitor of glutamatergic signaling plus anti-PD-1, an immune-checkpoint inhibitor. Tumor burden is monitored every 6 weeks for 18 weeks using a small imaging system, IVIS and tumor burden is quantified using ImageJ software. Blood, lymphoid, and tumor samples were collected at several time points during the study for molecular, and immune analyses.ResultsPreliminary results suggest a gender-biased treatment response and that the combination of troriluzole and anti-PD-1 is more efficacious than either agent alone. In males, a 43.9% reduction in tumor burden was observed while in females there was a 29.6% increase in tumor burden in the combination group compared to vehicle. In concordance, after the removal of the treatment modality, the male mice in the combinatorial group survived 42 days longer compared to vehicle controls with sustained tumor reduction by 68.3%. In female mice no significant advantage in survival or reduction in tumor burden was noted.ConclusionsN/A


2021 ◽  
Vol 205 ◽  
pp. 108480
Author(s):  
Mansour Rahimi ◽  
Sophie Leahy ◽  
Nathanael Matei ◽  
Norman P. Blair ◽  
Shinwu Jeong ◽  
...  

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