Biology subjects

Boye, S. L.

Publications and source records attributed to Boye, S. L..

7 recordsLinked to original sources

bioRxiv2026

Preclinical Development and Safety of Laterally Spreading Dual AAV.SPR-MYO7A Vectors for the Treatment of Usher Syndrome Type 1B

Usher syndrome type 1B (USH1B), caused by mutations in MYO7A, is the most severe form of Usher syndrome and accounts for more than 50% of USH1 cases. Affected patients are born profoundly deaf with vestibular dysfunction and develop progressive retinitis pigmentosa, for which no approved treatment exists. The MYO7A coding sequence exceeds the packaging capacity of adeno-associated virus (AAV), the gold standard vector for retinal gene therapy. To overcome this, we developed dual AAV hybrid and overlap platforms to reconstitute full-length MYO7A expression in photoreceptors and retinal pigment epithelium. Modification of cDNA split points, and reduction of non-coding sequence yielded optimized vector pairs that produced higher full-length MYO7A levels with substantially reduced truncated protein. Packaging in the laterally spreading AAV.SPR capsid enabled supraphysiological MYO7A expression in cynomolgus macaques at macular and distal retinal sites without requiring foveal detachment, an important safety consideration for USH1B patients with remaining central vision. A six-month GLP toxicology study confirmed that ATSN-301, an AAV.SPR-based dual vector reconstituting MYO7A driven by the smCBA promoter, was well tolerated at all doses, with a No Observed Adverse Effect Level established at 1.2E11 vg/eye, supporting its clinical advancement for USH1B.

genetics↗

bioRxiv2026

AAV-mediated age- and circuit-dependent restoration of photoreceptor synaptic structure and function in α2δ4-associated retinal synaptopathy

PurposeSynaptic dysfunction and neurite remodeling are early features of many inherited retinal diseases, but whether synaptic function can be restored after circuit remodeling remains unclear. We evaluated the therapeutic potential of adeno-associated virus (AAV)-mediated 2{delta}4 gene supplementation in a mouse model of CACNA2D4-associated retinal synaptopathy. MethodsAAV8-GRK1-2{delta}4 was delivered by subretinal injection to 2{delta}4 knockout mice at neonatal, young adult, or middle-aged adult stages. Retinal function was assessed by electroretinography. Synaptic organization and circuit remodeling were evaluated by immunohistochemistry. ResultsAAV-mediated 2{delta}4 expression restored synaptic localization of Cav1.4, ELFN proteins, and mGluR6 at all treatment ages. However, circuit structure and functional rescue were age- and circuit-dependent. Neonatal treatment restored rod and cone transmission and prevented photoreceptor terminal retraction and bipolar cell dendritic sprouting. Rescue in young adults improved rod and cone circuit function but did not reverse neurite remodeling. Rescue in middle-aged mice restored cone but not rod transmission. Notably, neonatal treatment produced the highest proportion of synapses within synaptic layer, whereas adult treatment generated increasing ectopic synapses in nuclear layer. ConclusionsPhotoreceptor synaptic assembly remains plastic in remodeled retinas and can be restored by 2{delta}4 supplementation. However, rescue efficacy is influenced by age and circuits with rod circuits exhibiting a narrower therapeutic window. Synaptic molecular reassembly can occur without neurite restoration. These findings establish 2{delta}4 gene therapy as a promising treatment for CACNA2D4-associated retinal synaptopathy and reveal distinct intervention windows for synaptic assembly, neurite remodeling, and rod versus cone circuit recovery.

neuroscience↗

bioRxiv2024

Dual-acting gene therapy targeting HIF1A and HIF2A by RNA interference mitigates retinal degeneration in two mouse models of AMD

Age-related tissue changes lead to reduced oxygen delivery to photoreceptors and the retinal pigment epithelium (RPE), and contribute to the pathology of age-related macular degeneration (AMD). The implication of hypoxia-inducible factors (HIFs) in this process makes them good candidates as therapeutic targets for AMD. We developed a multiplex dual-acting therapy utilizing the shRNAmir system, delivered by a single AAV, that reduces mRNA levels of Hif1a in photoreceptors and Hif2a in the RPE. This RNA interference-based strategy demonstrated a strong therapeutic effect, potently preserving photoreceptors and the RPE in two models of pseudo- and true hypoxia up to 61 weeks post-injection. The efficacy of our dual-acting virus proved superior to single-acting viruses targeting only Hif1a in photoreceptors or Hif2a in the RPE. By targeting a common, conserved disease pathway, this gene-agnostic RNAi therapy shows significant potential to protect tissues from chronic hypoxic insults in complex diseases such as AMD.

neuroscience↗

bioRxiv2023

Improving retinal vascular endothelial cell tropism through rational rAAV capsid design

Vascular endothelial cells (VEC) are essential for retinal homeostasis and their dysfunction underlies pathogenesis in diabetic retinopathy (DR) and exudative age-related macular degeneration (AMD). Studies have shown that recombinant adeno-associated virus (rAAV) vectors are effective at delivering new genetic material to neural and glial cells within the retina, but targeting VECs remains challenging. To overcome this limitation, herein we developed rAAV capsid mutant vectors with improved tropism towards retinal VEC. rAAV2/2, 2/2[QuadYF-TV], and rAAV2/9 serotype vectors (n=9, capsid mutants per serotype) expressing GFP were generated by inserting heptameric peptides (7AA) designed to increase endothelial targeting at positions 588 (2/2 and 2/2[QuadYF-TV] or 589 (2/9) of the virus protein (VP 1-3). The packaging and transduction efficiency of the vectors were assessed in HEK293T and bovine VECs using Fluorescence microscopy and flow cytometry, leading to the identification of one mutant, termed EC5, that showed improved endothelial tropism when inserted into all three capsid serotypes. Intra-ocular and intravenous administration of EC5 mutants in C57Bl/6j mice demonstrated moderately improved transduction of the retinal vasculature, particularly surrounding the optic nerve head, and evidence of sinusoidal endothelial cell transduction in the liver. Most notably, intravenous administration of the rAAV2/2[QuadYF-TV] EC5 mutant led to a dramatic and unexpected increase in cardiac muscle transduction.

molecular biology↗

bioRxiv2020

Gene Therapy Reforms Photoreceptor Structure and Restores Vision in NPHP5-associated Leber Congenital Amaurosis

The inherited childhood blindness caused by mutations in NPHP5, a form of Leber congenital amaurosis, results in abnormal development, dysfunction and degeneration of photoreceptors. A naturally occurring NPHP5 mutation in dogs results in a phenotype that very nearly duplicates the human retinopathy in terms of the photoreceptors involved, spatial distribution of degeneration and the natural history of vision loss. We show that AAV-mediated NPHP5 gene augmentation of mutant canine retinas at the time of active degeneration and peak cell death stably restores photoreceptor structure, function, and vision with either the canine or human NPHP5 transgenes. Mutant cone photoreceptors, which failed to form outer segments during development, reform this structure after treatment. Degenerating rod photoreceptor outer segments are stabilized and develop normal structure. This process begins within 8 weeks following treatment, and remains stable throughout the 6 month post treatment period. In both photoreceptor cell classes, mislocalization of rod and cone opsins is minimized or reversed. Retinal function and functional vision are restored. Efficacy of gene therapy in this large animal ciliopathy model of Leber congenital amaurosis provides a path for translation to human treatment.

neuroscience↗

bioRxiv2020

SARM1 depletion rescues NMNAT1 dependent photoreceptor cell death and retinal degeneration.

Leber congenital amaurosis type 9 is an autosomal recessive retinopathy caused by mutations of the NAD+ synthesis enzyme NMNAT1. Despite the ubiquitous expression of NMNAT1, patients do not manifest pathologies other than retinal degeneration. Here we demonstrate that widespread NMNAT1 depletion in adult mice mirrors the human pathology, with selective loss of photoreceptors highlighting the exquisite vulnerability of these cells to NMNAT1 loss. Conditional deletion demonstrates that NMNAT1 is required within the photoreceptor. Mechanistically, loss of NMNAT1 activates the NADase SARM1, the central executioner of axon degeneration, to trigger photoreceptor death and vision loss. Hence, the essential function of NMNAT1 in photoreceptors is to inhibit SARM1, highlighting an unexpected shared mechanism between axonal degeneration and photoreceptor neurodegeneration. These results define a novel SARM1-dependent photoreceptor cell death pathway and identifies SARM1 as a therapeutic candidate for retinopathies.

neuroscience↗

bioRxiv2018

Complement C3-targeted gene therapy restricts onset and progression of neurodegeneration in chronic mouse glaucoma

Dysregulation of the complement system is implicated in neurodegeneration, including human and animal glaucoma. Optic nerve and retinal damage in glaucoma is preceded by local complement upregulation and activation, but whether targeting this early innate immune response could have therapeutic benefit remains undefined. Because complement signals through three pathways that intersect at complement C3 activation, here we targeted this step to restore complement balance in the glaucomatous retina, and to determine its contribution to degeneration onset and/or progression. To achieve this, we combined adeno-associated viral retinal gene therapy with the targeted C3 inhibitor CR2-Crry. We show that intravitreal injection of AAV2.CR2-Crry produced sustained Crry overexpression in the retina, and reduced deposition of the activation product complement C3d on retinal ganglion cells and the inner retina of DBA/2J mice. This resulted in neuroprotection of retinal ganglion cell axons and somata despite continued intraocular pressure elevation, suggesting a direct restriction of neurodegeneration onset and progression, and significant delay to terminal disease stages. Our study uncovers a damaging effect of complement C3 or downstream complement activation in glaucoma and establishes AAV2.CR2-Crry as a viable therapeutic strategy to target pathogenic C3-mediated complement activation in the glaucomatous retina.

neuroscience↗