Biology subjects

Bruno, D.

Publications and source records attributed to Bruno, D..

7 recordsLinked to original sources

bioRxiv2026

Drosophila melanogaster as a platform for the functional expression of engineered PET-degrading enzymes

Insects offer promising opportunities for organic waste bioconversion; however, they cannot efficiently degrade synthetic polymers such as polyethylene terephthalate (PET). Here, we generated transgenic Drosophila melanogaster lines to express in vitro-evolved variants of two PET-degrading enzymes with distinct biochemical properties: an engineered Ideonella sakaiensis PETase variant (TS-{Delta}IsPET) and a leaf-branch compost cutinase variant (TA-{Delta}LCC). Both enzymes, fused to a Drosophila gut-derived secretory signal, were produced and secreted by both Drosophila cultured S2R+ cells and transgenic larvae. Both enzymes were glycosylated upon secretion, a post-translational modification that did not abolish their catalytic activity. Notably, TA-{Delta}LCC displayed [~]6-fold higher esterase activity than TS-{Delta}IsPET in larval extracts and TA-{Delta}LCC-containing extracts depolymerised PET nanoparticles in vitro under enzyme-favourable conditions. Transgenic flies showed normal development, fertility and survival. Morphological and biochemical analysis confirmed that TA-{Delta}LCC expression did not alter midgut structure and function. Together, these results establish Drosophila melanogaster as a model for functional expression and comparative evaluation of engineered PET-degrading enzymes and identify TA-{Delta}LCC as a promising candidate for exploitation in insect species relevant to plastic contaminated waste bioconversion. HighlightsO_LITransgenic D. melanogaster enables in vivo study of engineered PET enzymes C_LIO_LIEngineered TS-{Delta}IsPET and TA-{Delta}LCC are functional in larval extracts C_LIO_LITA-{Delta}LCC was selected for PET nanoparticle assays due to higher pNPA activity C_LIO_LID. melanogaster model enables comparative evaluation of PET-degrading enzymes C_LI

biochemistry↗

bioRxiv2026

Sex-specific associations between astrocytic reactivity and cognitive decline in unimpaired elderly

INTRODUCTIONAstrocyte reactivity may contribute to increased Alzheimers disease (AD) risk in women. Although higher plasma glial fibrillary acidic protein (GFAP) levels have been reported in women, few studies have investigated sex-specific relationships with other plasma AD biomarkers and cognition. METHODSParticipants were enrolled in the Memory Education and Research Initiative, a longitudinal community-based cohort, and underwent evaluation including blood biomarker sampling. The Alzheimers Disease Neuroimaging Initiative (ADNI) was included as a replication cohort. RESULTSUnimpaired women exhibited higher plasma GFAP levels than men (N=584). Higher baseline GFAP was associated with worse longitudinal episodic memory, exclusively in women. In addition, both higher baseline and increasing GFAP levels over time were associated with lower longitudinal plasma A{beta}42/40 ratio. The key results were replicated in the ADNI cohort. DISCUSSIONThese findings suggest that astrocytic reactivity is more pronounced in women and may contribute to sex-specific vulnerability to AD-related pathology and cognitive decline.

neuroscience↗

bioRxiv2025

The ontogeny of myeloid-stromal synovial tissue niches in rheumatoid arthritis.

Recent single-cell multi-omic and spatial analyses of synovial biopsies have transformed our understanding of myeloid cell-driven mechanisms underlying human joint pathology and tissue homeostasis in Rheumatoid arthritis (RA). However, the developmental trajectories of synovial tissue macrophage (STM) subsets in humans remain poorly understood, due in part to the lack of models that faithfully replicate synovial tissue niches. This hinders the exploration of the therapeutic potential of targeting specific synovial myeloid cell clusters. Using multi-omics analyses of synovial tissue from an allogeneic bone marrow transplant recipient, we show that joint-specific tissue-resident STM subsets, including both health- and disease-associated clusters, can derive from peripheral blood monocytes. Analysis of embryonic synovial joints revealed that macrophage localization and maturation in the joints are preceded by local stromal niche specialisation, indicating that synovial fibroblasts (FLS) provide tissue-specific instructive cues to STM precursors. To elucidate human STM developmental trajectories, we established a SNP-based fate-tracking human synovial organoid system by embedding distinct blood-derived myeloid precursors, together with FLS clusters from RA synovial biopsies and endothelial cells, into 3D structures. These organoids reproduced key synovial tissue features, including lining and sublining architecture and stromal-myeloid cell cluster composition. Importantly, they supported differentiation of all resident STM subsets: homeostatic lining TREM2pos macrophages, their pathogenic TREM2lowSPP1pos counterparts that characterize the RA hyperplastic lining, and both homeostatic and RA-associated perivascular LYVE1pos STM clusters, all traced to monocytic precursors. In summary, we show that development of STM subsets is driven by fibroblast-conditioned spatial niches. We have established a novel, tractable ex vivo platform to dissect the niche-specific cues driving homeostatic versus pathogenic phenotypic clusters. One Sentence SummaryHuman tissue-resident STMs develop from monocytes under the guidance of cues from FLS within discrete spatial locations.

immunology↗

bioRxiv2024

Distinct tissue-niche localization and function of synovial tissue myeloid DC subsets in health, and in active and remission Rheumatoid Arthritis

Current rheumatoid arthritis (RA) treatments do not restore immune tolerance. Investigating dendritic cell (DC) populations in human synovial tissue (ST) may reveal pathways to re-instate tolerance in RA. With single-cell and spatial-transcriptomics of synovial tissue biopsies, validated by micro co-culture systems, we identified condition and niche-specific myeloid DC clusters with distinct differentiation trajectories and functions. Healthy synovium contains a unique tolerogenic AXLpos DC2 cluster in the superficial sublining layer. In active RA, a macrophage-rich lining-layer niche becomes populated with inflammatory DC3 clusters that specifically activate memory CCL5pos TEM and CCL5posCXCL13pos TPH, promoting synovitis. In the sublining lymphoid niche, CCR7pos DC2 mReg specifically interact with naive-T-cells, potentially driving the local expansion of new effector T-cells. Sustained remission sees the resolution of these niches but lacks the recovery of tolerogenic AXLpos DC2, indicating latent potential for disease flare. A human RA disease-flare model showed that the activation of blood predecessor of ST-DC3 clusters precedes the onset of inflammation in joints. Therapeutic strategies targeting pathogenic ST-DC3 clusters, or reinstating tolerogenic AXLpos DC2, may restore immune homeostasis in RA. In briefDeconstruction of human RA synovium, using single-cell spatial transcriptomics and micro-culture systems, reveals distinct neighbourhoods within the synovial architecture across health, and RA patients with active disease or sustained remission. Discrete niches are identified that contain distinct myeloid DC clusters that differ in frequency, differentiation trajectories, and effector functions. HighlightsO_LIHuman RA synovium exhibits condition and niche specific myeloid DC clusters that vary in their tissue differentiation trajectories and functions. C_LIO_LIST-CD14pos DC3 (iDC3) support inflammatory CCL5pos TEM and CCL5pos TPH cell activation in the hyperplastic lining layer. C_LIO_LIST-CCR7pos DC2 (mReg), driven by MIR155, interact with naive-T-cells in sublining lymphoid niches. C_LIO_LIA specific inflammatory signature of blood predecessors of ST-DC3s predict flare in RA. C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=199 HEIGHT=200 SRC="FIGDIR/small/600758v1_ufig1.gif" ALT="Figure 1"> View larger version (74K): org.highwire.dtl.DTLVardef@27ab01org.highwire.dtl.DTLVardef@4be238org.highwire.dtl.DTLVardef@1f10734org.highwire.dtl.DTLVardef@1102056_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

Delayed primacy recall performance predicts post mortem Alzheimers disease pathology from unimpaired ante mortem cognitive baseline

INTRODUCTIONWe propose a novel method to assess delayed primacy in the CERAD memory test. We then examine whether this measure predicts post mortem Alzheimers disease (AD) neuropathology in individuals who were clinically unimpaired at baseline. METHODSA total of 1096 individuals were selected from the Rush Alzheimers Disease Center database registry. All participants were clinically unimpaired at baseline, and had subsequently undergone brain autopsy. Average age at baseline was 78.8 (6.92). A Bayesian regression analysis was carried out with global pathology as outcome; demographic, clinical and APOE data as covariates; and cognitive predictors, including delayed primacy. RESULTSGlobal AD pathology was best predicted by delayed primacy. Secondary analyses showed that delayed primacy was mostly associated with neuritic plaques, whereas total delayed recall was associated with neurofibrillary tangles. DISCUSSIONWe conclude that CERAD-derived delayed primacy is a useful metric for early detection and diagnosis of AD in unimpaired individuals.

neuroscience↗

bioRxiv2020

Human saphenous vein provides a unique source of anti-calcific pericytes for prosthetic cardiac valve engineering

AimsTissue engineering seeks to improve the longevity of prosthetic heart valves, but the cell source of choice has yet to be determined. This study aimed to establish a mechanistic rationale supporting the suitability of human adventitial pericytes (APCs). Methods and ResultsAntigenically APCs were immunomagnetically sorted from saphenous vein leftovers of patients undergoing coronary artery surgery and antigenically characterized for purity. Unlike bone marrow-derived mesenchymal stromal cells (BM-MSCs), APCs were resistant to osteochondrogenic induction by high phosphate (HP), as assessed by cytochemistry and expression of osteogenic markers. MiR-132 is natively expressed by APCs, with copy numbers being enhanced by HP stimulation. In silico bioinformatic analysis, followed by luciferase assays in HEK293 cells and miR-132 titration using agomiR and antagomiR in APCs, demonstrated that several osteochondrogenic genes were negatively regulated by miR-132. Among these, the glycolytic marker GLUT1 was downregulated in HP-stimulated APCs. In contrast to BM-APCs, APCs showed no increase in glycolysis under HP. Interestingly, incubation with APC-derived conditioned medium conferred swine cardiac valves with resistance to osteogenic transformation by HP; whereas, conditioned media from miR-132-knocked-down APCs failed to prevent the expression of these markers. Finally, we demonstrated the feasibility of using APCs to engineer bovine pericardium patches. APCs proliferate in the patch and secrete factors able to attract aortic endothelial cells under HP. ConclusionsHuman APCs are resistant to calcification compared with BM-MSCs and convey the anti-calcific phenotype to heart valves through miR-132. These findings may open new important avenues for prosthetic valve cellularization.

cell biology↗

bioRxiv2020

Proper names from story recall are associated with beta-amyloid in cognitively unimpaired adults at risk for Alzheimer's disease

Due to advances in the early detection of Alzheimers disease (AD) biomarkers including beta-amyloid (A{beta}), neuropsychological measures that are sensitive to concurrent, subtle changes in cognition are critically needed. Story recall tasks have shown sensitivity to early memory declines in persons with Mild Cognitive Impairment and early stage dementia, as well as in persons with autosomal dominantly inherited AD up to 10 years prior to a dementia diagnosis. However, the evidence is inconclusive regarding relationships between evidence of A{beta} and story recall measures. Because story recall tasks require the encoding and delayed retrieval of several lexical-semantic categories, such as proper names, verbs, and numerical expressions, and because lexical categories have been shown to be differentially impaired in persons with MCI, we focused on item-level analyses of lexical-semantic retrieval from a quintessential story recall task, Logical Memory from the Wechsler Memory Scale. Our objective was to investigate whether delayed recall of lexical categories (proper names, verbs and/or numerical expressions), as well as the traditional total score measure, was associated with "preclinical AD," or cognitively unimpaired adults with positive A{beta} deposition on positron emission tomography (PET) neuroimaging using Pittsburgh Compound B. We developed an item-level scoring system, in which we parsed items into lexical categories and examined the immediate and delayed recall of these lexical categories from 217 cognitively unimpaired participants from the Wisconsin Registry for Alzheimers Prevention. We performed binary logistic regression models with story recall score as predictor and A{beta} status (positive/negative) as the outcome. Using baseline Logical Memory data, proper names from delayed story recall were significantly associated with A{beta} status, such that participants who recalled more proper names were less likely to be classified as PiB(+) (odds ratio = .58, p=.01). None of the other story recall variables, including total score, were associated with PiB status. Secondary analyses determined that immediate recall of proper names was not significantly associated with A{beta}, suggesting a retrieval deficit rather than that of encoding. The present findings suggest that lexical semantic retrieval measures from existing story recall tasks may be sensitive to A{beta} deposition, and may provide added utility to a widely-used, long-standing neuropsychological test for early detection of cognitive decline on the AD continuum.

neuroscience↗