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Biology subjects

Doman, E.

Publications and source records attributed to Doman, E..

4 recordsLinked to original sources

Fallopian Tube Organoid-Integrated Microfluidic Platform for Real-Time Imaging and Outflow Analysis

The fallopian tube is a dynamic, hormonally regulated epithelial conduit whose luminal microenvironment governs oocyte transport, fertilisation, early embryo development, and the initiation of gynaecological diseases including ectopic pregnancy, hydrosalpinx, and serous tubal intraepithelial carcinoma (STIC), yet existing models such as 2D monolayers, intact organoids, and static Transwell systems fail to recapitulate a polarised epithelium lining a perfused lumen under physiological fluid shear while preserving native organoid secretory function. We present a robust and accessible workflow integrating mechanically opened fallopian tube organoids into a custom-designed polydimethylsiloxane (PDMS) microfluidic device, in which organoid fragments form epithelial sheets and re-establish luminal-like architecture under controlled perfusion. The focus of this study is organoid integration and the characterisation of the resulting organoid-derived epithelium, rather than establishing chip cultures from individual cell lines. As this epithelium is built from expandable organoid stock rather than primary tissue, which typically survives only a few days in culture, the approach removes a major bottleneck to establishing organ-on-chip models, and we maintain viable cultures for up to 10 days. Epithelial sheets reproducibly covered more than 90% of the channel area by day 6 (n = 5 devices) and formed continuous ZO-1-positive tight junctions. The platform supports longitudinal brightfield and fluorescence microscopy at subcellular resolution, continuous collection of conditioned flow-through for ELISA, and quantitative analysis of cell coverage and health using CellProfiler software. We characterise the organoid-derived epithelium by benchmarking against tissue culture (TC) formats, comparing nuclear morphology on-chip with conventional well culture, and showing that the damage-associated cytokine interleukin-1 alpha (IL1 alpha) was undetectable in chip outflow, as in intact organoid secretions, indicating that cell health on-chip is comparable to that of intact organoids. Computational flow modelling characterises perfusion through the device and predicts how factors secreted by healthy epithelium and by tumour cells are distributed along the channel. The feasibility of tumour epithelium co culture was explored using OVCAR3 ovarian cancer spheroids as a proof of concept model of early tumour interaction with the tubal epithelium. Together, these results establish the technical feasibility of the platform and support its further development as an accessible system for studying reproductive health conditions affecting the fallopian tube, including tubal damage from infection, endometriosis, STIC lesions, and occlusion.

bioengineering↗

Higher-Order Organization Links Circulating Metabolites to Glucocorticoid Action in Human Adipose Tissue

Glucocorticoids (GCs) are regulators of metabolism, yet how physiological GC exposure remodels adipose metabolism and its relationship with circulating biomarkers remains poorly understood. In a randomised cross-over study of individuals with primary adrenal insufficiency, near-physiological GC exposure was compared to withdrawal using integrated serum metabolomics, abdominal subcutaneous microdialysis metabolomics, and adipose tissue transcriptomics. GC exposure induced coordinated changes in adipose lipid and amino-acid metabolism. Pathway-level entropy analysis revealed GC-state-dependent transcriptional reorganisation, with concentrated organisation during exposure and diffuse organisation during withdrawal. Integrative hypergraph and topological analyses revealed GC-state-dependent reorganisation of circulating metabolite-adipose tissue relationships, with greater higher-order coordination during exposure. The circulating phenylalanine/kynurenine ratio discriminated GC state, showed the strongest shared connectivity to GC-regulated adipose networks, persisted at midnight and in an independent dose-response study, and exhibited circadian rhythmicity. These findings reveal dynamic GC regulation of adipose metabolism and identify a circulating biomarker with potential to guide personalised GC therapy.

systems biology↗

Red blood cell dynamics in extravascular biological tissues modelled as canonical disordered porous media

The dynamics of blood flow in the smallest vessels and passages of the human body, where the cellular character of blood becomes prominent, plays a dominant role in the transport and exchange of solutes. Recent studies have revealed that the micro-haemodynamics of a vascular network is underpinned by its interconnected structure, and certain structural alterations such as capillary dilation and blockage can substantially change blood flow patterns. However, for extravascular media with disordered microstructure (e.g., the porous intervillous space in the placenta), it remains unclear how the mediums structure affects the haemodynamics. Here, we simulate cellular blood flow in simple models of canonical porous media representative of extravascular biological tissue, with corroborative microfluidic experiments performed for validation purposes. For the media considered here, we observe three main effects: first, the relative apparent viscosity of blood increases with the structural disorder of the medium; second, the presence of red blood cells (RBCs) dynamically alters the flow distribution in the medium; third, increased structural disorder of the medium can promote a more homogeneous distribution of RBCs. Our findings contribute to a better understanding of the cellscale haemodynamics that mediates the relationship linking the function of certain biological tissues to their microstructure.

biophysics↗

Interpreting coronary artery disease risk through gene-environment interactions in gene regulation

GWAS and eQTL studies identified thousands of genetic variants associated with complex traits and gene expression. Despite the important role of environmental exposures in complex traits, only a limited number of environmental factors are measured in these studies. Measuring molecular phenotypes in tightly controlled cellular environments provides a more tractable setting to study gene-environment interactions in the absence of other confounding variables.\n\nWe performed RNA-seq and ATAC-seq in endothelial cells exposed to retinoic acid, dexamethasone, caffeine, and selenium to model genetic and environmental effects on gene regulation in the vascular endothelium, a common site of pathology in cardiovascular disease. We found that genes near regions of differentially accessible chromatin were more likely to be differentially expressed (OR = [3.41, 6.52], p < 10-16). Furthermore, we confirmed that environment-specific changes in transcription factor binding are a key mechanism for cellular response to environmental stimuli. SNPs in these transcription response factor footprints for dexamethasone, caffeine, and retinoic acid were enriched in GTEx eQTLs from artery tissues indicating that these environmental conditions are latently present in GTEx samples. Additionally, SNPs in footprints for response factors in caffeine are enriched in colocalized eQTLs for coronary artery disease (CAD), suggesting a role for caffeine in CAD risk. Interestingly, each treatment may amplify or buffer genetic risk for CAD, depending on the particular SNP considered.

genomics↗