Biology subjects

Green, J. A.

Publications and source records attributed to Green, J. A..

5 recordsLinked to original sources

bioRxiv2026

TET1 Functions as an Oxidized LDL Dependent Early-Stage Inducer of Atherosclerosis by Initiating Foam Cell Formation in Macrophages

Atherosclerosis is a condition characterized by plaque growths in arteries, consisting of oxidized LDL (low-density lipoprotein) and localized cell cumulation. By the time of diagnosis for patients with atherosclerosis, the disease has often progressed into advanced stages. Statins are commonly prescribed; however, while these drugs can lower blood cholesterol levels, they cannot regress or stop the plaque growth. Currently, there are no treatments available to prevent the formation of new plaques. Such treatment options would require the identification of proteins that act during disease onset, initiating molecular mechanisms that promote plaque formation. Histone deacetylases (HDACs) and Ten Eleven Translocation (TET) demethylases are two important classes of epigenetic mediators. Some isoforms of these two classes of proteins have been found to transcriptionally regulate cellular inflammation, which may favor plaque formation. These transcriptional regulators seem to function early in the molecular mechanisms that are involved in disease progression. In the present work, we identified a clear role of these epigenetic proteins in foam cell formation. Foam cells have been implicated as part of the early steps which ultimately lead to atherosclerosis. Here we showed that in the presence of OxLDL (oxidized LDL), the protein isoform TET1 has a direct role in foam cell formation, while HDAC2 adopts a more indirect role. Using specific inhibitors of TET1 and HDAC2, we showed the inter-regulated molecular mechanisms between these proteins and how they regulate foam cell formation in vitro. In this study, we found that upon inhibition of TET1 in U937-derived macrophages, and subsequent foam cell formation via OxLDL treatment, a lower percentage of foam cells was observed. However, TET2 inhibition under the same treatment conditions had no effect on the inhibition of foam cell formation.

immunology↗

bioRxiv2025

Efficient in vivo mammalian neuron editing using peptide-mediated CRISPR enzyme delivery

CRISPR-mediated genome editing of the central nervous system (CNS) has the potential to revolutionize the treatment of neurological disorders, including neurodegenerative disorders such as Huntingtons disease (HD). However, the development of CRISPR therapeutics for the CNS has been hindered by challenges associated with delivery, specifically the lack of a clinically compatible, non-viral delivery technology facilitating genome editing of neurons in vivo. For most indications, two key obstacles must be overcome before therapeutic genome editing of the brain is feasible: non-toxic intracellular delivery of CRISPR cargo into neurons and establishment of strategies enabling targeted brain regions to be edited efficiently. While viral vectors have shown promise in pre-clinical models, non-viral approaches present distinct advantages: ease of manufacture as well as the transient presence of CRISPR machinery, which tempers risks of genotoxicity and immunogenicity. Peptide-enabled ribonucleoprotein (RNP) delivery of CRISPR (PERC) has emerged as a promising non-viral delivery strategy for CRISPR enzymes with initial use in primary human immune cells. In this study, we report the development of Neuro-PERC, a streamlined and optimized approach for in vivo editing of mammalian neurons. Administration of Neuro-PERC reagents via convection-enhanced delivery (CED) mediated efficient and well-tolerated neuronal genome editing. Neuro-PERC enabled robust neuronal editing in the brain of both small and large animal reporter models, and increased survival in a severe murine model of Huntingtons disease. These results establish CED-administered Neuro-PERC as a candidate delivery technology to hasten clinical translation of CRISPR-based therapies for diseases of the CNS. SummaryNeuro-PERC, a peptide-mediated CRISPR enzyme delivery technology, enables efficient in vivo mammalian neuronal editing in the brain of mice and pigs, extending survival in a murine model of Huntingtons disease when administered via convection-enhanced delivery (CED).

neuroscience↗

bioRxiv2025

RHO1-2 meganuclease gene editing targets human P23H rhodopsin-induced retinitis pigmentosa to rejuvenate rods and maintain cones

Autosomal dominant retinitis pigmentosa (adRP) is an inherited retinal dystrophy characterized by progressive vision loss and eventual blindness. The P23H mutation (proline to histidine substitution at codon 23) in the rhodopsin (RHO) gene represents the most common form of adRP in North Americans. Currently, there is no cure for P23H adRP. Genome editing targeting the mutant RHO allele, leaving a functional wildtype (WT) allele, is an attractive approach for P23H adRP, as only one copy of RHO is needed for normal retinal function. We re-engineered an I-Cre meganuclease, called RHO1-2, to target a 22bp recognition sequence encompassing the mutation responsible for the p.P23H RHO mutation. In vitro, RHO1-2, cuts human P23H RHO but not WT RHO. In vivo, we delivered scAAV5:GRK1:RHO1-2 via subretinal injection in early-stage degeneration using the only large animal model of human p.P23H RHO adRP (TgP23H pigs). We tested RHO1-2 efficacy and durability, on retinal function using full-field electroretinograms and on retinal structure using spectral domain optical coherence tomography and immunohistochemistry. We observe that RHO1-2 treatment: arrests rod photoreceptor degeneration, resurrects rod-driven retinal function that does not exist in untreated TgP23H pigs, restores mislocalized rhodopsin expression and rebuilds rod inner and outer segments (IS/OS). Rod rescue maintains cones. A year after RHO1-2 treatment, we show that TgP23H pigs use rod-driven vision to navigate a maze. Our results demonstrate that genome editing via RHO1-2 meganuclease is a viable treatment to cure human p.P23H RHO adRP. They also suggest that meganuclease-based editors can be effective for other IRDs. One Sentence SummaryEngineered meganuclease, RHO1-2 is a safe and promising therapeutic genome editing approach to cure human p.P23H RHO adRP.

neuroscience↗

bioRxiv2024

Temporal and spatial variability in availability bias has consequences for marine bird abundance estimates during the non-breeding season

O_LITo effectively monitor how marine ecosystems are being reshaped by anthropogenic pressures, we require understanding of species abundances and distributions. Due to their socio-economic and ecological value, predatory species are often at the forefront of survey efforts. However, survey data are only valuable if they can reliably be converted into estimates of underlying distributions. C_LIO_LIWe consider at-sea surveys of marine predators that often inform ecological impact assessments of offshore windfarms. These surveys are subject to a form of detection bias called availability bias whereby individuals which are submerged below the surface are consequently unavailable for detection. Although correction factors are commonly used in these surveys, they are currently based on limited data that may not be species-, time-, or area-specific. Here, we use time-depth-recorder data to investigate variation in marine bird availability bias. C_LIO_LIWe found that the proportion of diving marine birds submerged below the sea surface during daylight hours, and therefore unavailable to be counted during surveys, varied by species, month, and area. For three of our focal species wintering around northwest Europe (Atlantic puffin, common guillemot, razorbill) our results were different to comparable values previously used to correct for the availability bias, whereas no correction factors are regularly used for the fourth species (red-throated diver). We now present availability bias correction factors that are species- and month-specific to the areas the study populations use during their non-breeding seasons: the North Sea, the north and west coasts of the UK, the Baltic Sea, and Icelandic coastal waters. C_LIO_LISynthesis and applications: Variation in the proportion of daylight hours that marine birds spent submerged lead to differences in availability bias correction factors, thereby impacting estimations of their abundances. We encourage use of correction factors that use data from the species, marine area, and month during which surveys are conducted to provide more accurate abundance estimates. Using more relevant correction factors will result in increasingly accurate abundance and distribution estimates of diving marine birds, with relevance for a range of applications including planning for offshore windfarm developments, the designation and monitoring of protected areas, and understanding environmental change. C_LI

ecology↗

bioRxiv2020

Small RNAome of ageing chondrocytes

BackgroundAgeing is one of the leading risk factors predisposing cartilage to musculoskeletal diseases, including osteoarthritis. Cumulative evidence suggests that small non-coding RNAs play a role in cartilage-related pathological changes. However, little research has been conducted on the effect of ageing on the expression of small non-coding RNAs in cartilage. By using small RNA sequencing, we investigated changes in the expression of small non-coding RNAs between young and old equine chondrocytes. MethodsChondrocytes were extracted from five young (4{+/-}1 years) and five old (17.4{+/-}1.9 years) macroscopically normal equine metacarpophalangeal joints. Following RNA extraction cDNA libraries were prepared and subjected to small RNA sequencing using the Illumina MiSeq platform. Differential expression analysis was performed in R using package DESeq2. For tRNA fragment analysis, tRNA reads were aligned to horse tRNA sequences using Bowtie2 version 2.2.5. Selected microRNA and small nucleolar RNA findings were validated using qRT-PCR in an extended cohort of equine chondrocytes. tRNA fragments were further investigated in low and high grade OA human cartilage tissue. ResultsIn total, 83 sncRNAs were differentially expressed between young and old equine chondrocytes, including microRNAs, snoRNAs, snRNAs and tRNAs. Of these, 34 were expressed higher and 49 were expressed lower in old chondrocytes compared to young. qRT-PCR analysis confirmed findings in an extended cohort of equine chondrocytes. Ingenuity Pathway Analysis of differentially expressed microRNAs and their predicted target genes linked them to cartilage and OA-related pathways and diseases. tRNA fragment analysis revealed that tiRNA-5035-GluCTC and tiRNA-5031-GluCTC-1 were reduced in both high grade OA human cartilage and old equine chondrocytes. ConclusionFor the first time, we have measured the effect of ageing on the expression of small non-coding RNAs in equine chondrocytes. Changes were detected in a number of different sncRNA species, including microRNAs, small nucleolar RNAs and tRNA fragments. This study supports a role for small non-coding RNAs in ageing cartilage and their potential involvement in age-related cartilage diseases.

molecular biology↗