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Devlin, A.

Publications and source records attributed to Devlin, A..

4 recordsLinked to original sources

Loss of lmx1ba drives premature osteoarthritis through disruption of skeletal homeostasis

Osteoarthritis is increasingly recognised as a disease of failed integration across the whole joint unit; however, the mechanisms that co-ordinate tissue integrity from development through to adult homeostasis remain largely unresolved. The LIM-homeodomain transcription factor LMX1B is a key determinant of embryonic skeletal patterning, but how it functions to regulate skeletal integrity in the mature skeleton is unknown. Recently, LMX1B was identified as a key driver of osteoarthritis. Here we show that loss of lmx1ba in zebrafish causes premature and progressive severe osteoarthritic pathology in adult spines and jaws, despite largely normal early skeletal patterning, revealing a conserved and continuous requirement for lmx1ba in joint maintenance beyond development. At a cellular level, loss of lmx1ba decouples osteoblast and osteoclast-mediated remodelling leading to bone overgrowth, heterogeneity of bone properties causing increased incidence of spontaneous fractures, and progressive abnormalities in spine morphology. In parallel, we observe degeneration of the intervertebral disc and dysregulation of the proteome and glycosaminoglycans indicative of disrupted extracellular matrix and a breakdown of the coordinated regulation of hard and soft tissue interfaces, which at the organismal level leads to altered joint performance. Notably, degeneration is restricted to mobile joints, and is not observed in cranial sutures, demonstrating a selective requirement for lmx1ba in mechanically active tissues. These changes are consistent with a model of spatially disrupted matrix properties that, under cyclic loading, promote progressive tissue damage. Our findings support a model in which continued expression of LMX1B in adulthood is required to maintain joint structures throughout life.

physiology↗

X-CODE: a dual RNA barcoding system for multi-platform clonal tracking and spatial phenotyping

Experimental dissection of clonal dynamics in complex tissues requires barcoding systems that are scalable, compatible with different analytical platforms, providing phenotypic and spatial resolution. Here we introduce X-CODE, a dual-expressed RNA barcoding system designed to enable high-complexity clonal tracking across sequencing-based, cytometric, and spatial imaging modalities within a unified experimental framework. X-CODE combines a combinatorial, probe-detectable long RNA barcode with a matched short sequencing barcode, enabling seamless integration of probe-based readouts with sequencing and barcode-guided clonal retrieval. We demonstrate robust X-CODE detection by mass cytometry and imaging-based platforms, including spatial RNA barcode readout using via a repurposed Akoya PhenoCycler-Fusion protocol. In addition, we show compatibility with MALDI mass spectrometry imaging for co-registration of clonal and metabolic information. We further demonstrate the feasibility of X-CODE detection within probe-based spatial transcriptomics using the 10x Genomics Xenium platform. Applied to an in vivo model of androgen deprivation in prostate cancer, X-CODE reveals clonal architecture, selection and clone-specific phenotypic and metabolic plasticity underlying castration resistance. Together, X-CODE provides a flexible and broadly accessible platform for integrated clonal analysis across spatial, phenotypic, and molecular dimensions.

cancer biology↗

A glycosaminoglycan extract from Portunus pelagicus inhibits BACE1, the β secretase implicated in Alzheimer’s disease

Therapeutic options for Alzheimers disease, the most common form of dementia, are currently restricted to palliative treatments. The glycosaminoglycan heparin, widely used as a clinical anticoagulant, has previously been shown to inhibit the Alzheimers disease-relevant {beta}-secretase 1 (BACE1). Despite this, the deployment of pharmaceutical heparin for the treatment of Alzheimers disease is largely precluded by its potent anticoagulant activity. Furthermore, ongoing concerns regarding the use of mammalian sourced heparins, primarily due to prion diseases and religious beliefs, hinder the deployment of alternative heparin based therapeutics. A marine-derived, heparan sulphate-containing glycosaminoglycan extract isolated from the crab Portunus pelagicus, was identified to inhibit human BACE1 with comparable bioactivity to that of mammalian heparin (IC50 = 1.85 g.mL-1 (R2 = 0.94) and 2.43 g.mL-1 (R2 = 0.93), respectively) possessing highly attenuated anticoagulant activities. The results from several structural techniques suggest that the interactions between BACE1 and the extract from P. pelagicus are complex and distinct from those of heparin.

biochemistry↗

Analysis of solid-state heparin samples by ATR-FTIR spectroscopy

The widely used anticoagulant pharmaceutical, heparin, is a polydisperse, heterogeneous polysaccharide. Heparin is one of the essential medicines defined by the World Health Organisation but, during 2007-2008, was the subject of adulteration. The intrinsic heterogeneity and variability of heparin makes it a challenge to monitor its purity by conventional means. This has led to the adoption of alternative approaches for its analysis and quality control, some of which are based on multivariate analysis of 1H NMR spectra, or exploit correlation techniques. Such NMR spectroscopy-based analyses, however, require costly and technically demanding NMR instrumentation. Here, an alternative approach based on the use of attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) combined with multivariate analysis is proposed. FTIR-ATR employs more affordable and easy-to-use technology and, when combined with multivariate analysis of the resultant spectra, readily differentiates between glycosaminoglycans of different types, between heparin samples of distinct animal origins and enables the detection of both known heparin contaminants, such as over-sulphated chondroitin sulfate (OSCS), as well as other alien sulphated polysaccharides in heparin samples to a degree of sensitivity comparable to that achievable by NMR. The approach will permit the rapid and cost-effective monitoring of pharmaceutical heparin at any stage of the production process and indeed, in principle, the quality control of any heterogeneous or variable material.

biochemistry↗