Biology subjects

Boye, K.

Publications and source records attributed to Boye, K..

5 recordsLinked to original sources

bioRxiv2025

Restoring compromised Blood-Retina-Barrier integrity with Netrin-1 overexpression

The blood-retina barrier (BRB) protects retinal neuronal function and enables vision. A compromised, leaky BRB is a hallmark of vision-threatening retinal diseases such as diabetic retinopathy (DR) and wet age-related macular degeneration (AMD) that affect millions of persons worldwide. Strategies to enhance BRB integrity hold promise as therapeutic interventions to prevent vision loss. Previous studies identified Netrin-1 (NTN1) as a key regulator of BRB stability and revealed reduced Netrin-1 signaling in DR patients, suggesting that Netrin-1 supplementation could help preserve BRB function and prevent disease progression. Herein, we used genetic NTN1 overexpression to investigate effects on BRB development and maintenance. We show that global NTN1 overexpression converted leaky vessels at the P5 angiogenic front into a non-leaky state. In pathological settings, NTN1 overexpression reinforced BRB integrity in oxygen- induced retinopathy (OIR), improving electroretinogram (ERG) amplitudes and rescued vascular leak in laser-induced choroidal neovascularization (CNV). Mechanistically, we determined that NTN1 overexpression minimally and transiently affected retinal angiogenesis in an Unc5b independent manner, while Netrins barrier stabilizing effects were Unc5b dependent. These findings establish Netrin-1 as a promising therapeutic target for preventing BRB breakdown in retinal vascular diseases and suggest that reinforcing the Netrin-1/Unc5b signaling pathway may provide a strategy to selectively stabilize the BRB.

molecular biology↗

bioRxiv2023

The Minimal Dataset for Cancer of the 1+Million Genomes Initiative

For a real impact on healthcare, precision cancer medicine requires accessibility and interoperability of clinical and genomic data across centres and countries. Due to the heterogeneous digitization in Europe and worldwide, the definition of models for standardised data collection and usability becomes mandatory if countries want to work together on this mission. The European Union 1+Million Genomes (1+MG) initiative, supported by the Horizon 2020 Beyond 1 Million Genomes project, aims at outlining data models, guidance, best practices, and technical infrastructures for transnational access to sequenced genomes, including cancer genomes. Within the framework of the cancer-focused Working Group 9, we developed the 1+MG-Minimal Dataset for Cancer (1+MG-MDC)-a data model encompassing 140 items and organized in eight conceptual domains for the collection of cancer-related clinical information and genomics metadata. The 1+MG-MDC, which results from a multidisciplinary effort, leverages pre-existing models and emphasizes the annotation and traceability of multiple aspects relevant to the complex longitudinal path of the cancer disease and its treatment. We strived to make the 1+MG-MDC easy to adopt, yet comprehensive, addressing the needs of both clinicians and researchers. We will periodically revise and update it to ensure it remains fit for purpose. We propose the 1+MG-MDC as a model to create homogeneous databases, which would, in turn, guide discussions on clinical and genomic features with prognostic or therapeutic value and foster real-world data research.

cancer biology↗

bioRxiv2023

Netrin-1 binding to Unc5B regulates Blood-Retina Barrier integrity

BackgroundThe blood brain barrier (BBB) preserves neuronal function in the central nervous system (CNS) by tightly controlling metabolite exchanges with the blood. In the eye, the retina is likewise protected by the blood-retina barrier (BRB) to maintain phototransduction. We showed that the secreted guidance cue Netrin-1 regulated BBB integrity, by binding to endothelial Unc5B and regulating canonical {beta}-catenin dependent expression of BBB gene expression ObjectiveHere, we investigated if Netrin-1-binding to endothelial Unc5B also controlled BRB integrity, and if this process involved Norrin/{beta}-catenin signaling, which is the major known driver of BRB development and maintenance. MethodsWe analyzed Tamoxifen-inducible loss- and gain-of-function alleles of Unc5B, Ntn1 and Ctnnb1 in conjunction with tracer injections and biochemical signaling studies. ResultsInducible endothelial Unc5B deletion, and inducible global Ntn1 deletion in postnatal mice reduced phosphorylation of the Norrin receptor LRP5, leading to reduced {beta}-catenin and LEF1 expression, conversion of retina endothelial cells from a barrier-competent Claudin-5+/PLVAP-state to a Claudin-5-/PLVAP+ leaky phenotype, and extravasation of injected low molecular weight tracers. Inducible Ctnnb1 gain of function rescued vascular leak in Unc5B mutants, and Ntn1 overexpression induced BRB tightening. Unc5B expression in pericytes contributed to BRB permeability, via regulation of endothelial Unc5B. Mechanistically, Netrin-1-Unc5B signaling promoted {beta}-catenin dependent BRB signaling by enhancing phosphorylation of the Norrin receptor LRP5 via the Discs large homologue 1 (Dlg1) intracellular scaffolding protein. ConclusionsThe data identify Netrin1-Unc5B as novel regulators of BRB integrity, with implications for diseases associated with BRB disruption.

cell biology↗

bioRxiv2021

Endothelial Unc5B controls blood-brain barrier integrity

Blood-brain barrier (BBB) integrity is critical for proper function of the central nervous system (CNS). Here, we showed that the endothelial Netrin1 receptor Unc5B controls BBB integrity by maintaining Wnt/{beta}-catenin signaling. Inducible endothelial-specific deletion of Unc5B in adult mice led to region and size-selective BBB opening. Loss of Unc5B decreased BBB Wnt/{beta}-catenin signaling, and {beta}-catenin overexpression rescued Unc5B mutant BBB defects. Mechanistically, Netrin1 enhanced Unc5B interaction with the Wnt co-receptor LRP6, induced its phosphorylation and activated Wnt/{beta}-catenin downstream signaling. Intravenous delivery of antibodies blocking Netrin1 binding to Unc5B caused a transient disruption of Wnt signaling and BBB breakdown, followed by neurovascular barrier resealing. These data identify Netrin-Unc5B signaling as a novel regulator of BBB integrity with potential therapeutic utility for CNS diseases.

cell biology↗

bioRxiv2019

Multiple acyl-CoA thioesterases occupy distinct functional niches within the mitochondrial matrix

Acyl-CoA thioesterases (Acots) hydrolyze fatty acyl-CoA esters. Acots in the mitochondrial matrix are poised to mitigate {beta}-oxidation overload that may contribute to lipotoxicity. Several Acots associate with mitochondria, but whether they all localize to the matrix, and are redundant or have different roles is unresolved. We compared mitochondrial Acots (Acot2, 7, 9, and 13) in terms of suborganellar localization, activity, expression and regulation, in mitochondria from multiple mouse tissues and from a new model of Acot2 depletion. Acot7, 9 and 13 localized to the matrix, joining Acot2 that was previously shown to localize there. Mitochondria from heart, skeletal muscle, brown adipose tissue and kidney robustly expressed Acot2, 9 and 13, though Acot9 was substantially higher in brown adipose tissue and kidney mitochondria, as was activity for C4:0-CoA, a unique substrate of Acot9. In all these tissues, Acot2 accounted for [~]half of the thioesterase activity for C14-CoA and C16:0-CoA. In contrast, liver mitochondria from fed and fasted mice expressed little Acot activity, and this activity was confined to long-chain CoAs, and due mainly to Acot7 and Acot13 activity. Matrix Acots occupied different functional niches, based on substrate specificity (Acot9 vs. Acot2 and 13) and strong CoA inhibition (Acot7, 9, 13 but not Acot2). Interpreting these results in the context of {beta}-oxidation, CoA inhibition would prevent Acot-mediated suppression of {beta}-oxidation while providing for an Acot-mediated release valve when CoA is limiting. This release valve would operate across a wide range of acyl-CoA chain lengths. In contrast, CoA-insensitive Acot2 could provide a constitutive syphon for long-chain fatty acyl-CoAs. These results reveal how the family of matrix Acots can help to mitigate {beta}-oxidation overload and prevent a CoA limitation.

biochemistry↗