Biology subjects

Cahill, P. A.

Publications and source records attributed to Cahill, P. A..

6 recordsLinked to original sources

bioRxiv2026

A Biphasic Effect of Alcohol on Endothelial Plasticity Through Regulation of Endothelial-to-Mesenchymal Transition

BackgroundAlcohol consumption influences cardiovascular disease, but whether it does so by affecting endothelial plasticity is unknown. We tested whether alcohol regulates endothelial-to-mesenchymal transition (EndMT) to influence arterial pathology. MethodsHCAEC and HUVEC were exposed to inflammatory cytokines (TGF{beta} {+/-} IL1{beta}) or hypoxia in the presence of ethanol (0-100 mM). EndMT was assessed by changes in cell marker expression, SNAIL levels, and migration assays. In vivo, carotid ligation was performed in mice gavaged with/without either daily moderate ethanol (2-drink equivalent/d) or episodic binge exposure (7-drink equivalent, 2 days/week) and myo-endothelial cell population assessed. ResultsCytokines and hypoxia induced EndMT in vitro, characterized by loss of endothelial markers, increased mesenchymal markers, elevated SNAIL, and enhanced migratory capacity. Low-to-moderate dose ethanol (5-25 mM) attenuated these changes, preserving endothelial phenotype, whereas high dose ethanol (50-100 mM) either had no effect or exacerbated EndMT. The inhibitory effect of moderate ethanol on cytokine- and hypoxia-induced changes in SMA and Cdh5 expression was abrogated by {gamma}-secretase inhibition, consistent with involvement of Notch signaling. Carotid ligation induced neointimal formation and accumulation of myo-endothelial cells indicative of EndMT. Daily moderate ethanol significantly attenuated neointimal hyperplasia and diminished the myo-endothelial cell population, whereas in contrast, episodic binge ethanol exposure increased pathologic remodeling and myo-endothelial cell abundance. ConclusionsAlcohol modulates endothelial trans-differentiation in a biphasic manner. Low-to-moderate alcohol exposure suppresses EndMT and limits pathological remodeling, whereas binge-level exposure promotes these processes. These findings identify regulation of endothelial plasticity as a potential novel mechanism linking alcohol consumption patterns to vascular disease risk. NEW AND NOTEWORTHYWe identify a previously unrecognized biphasic effect of alcohol on endothelial phenotypic plasticity. Low-to-moderate dose alcohol suppresses endothelial-to-mesenchymal transition (EndMT), whereas high-level (binge) exposure promotes this pro-atherogenic process. Given the central role of EndMT in vascular remodelling and atherosclerosis, these findings provide a mechanistic framework linking alcohol consumption patterns and cardiovascular disease risk - potentially explaining both the protective effect at low/moderate levels, and the detrimental impact of heavy alcohol use. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/718463v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1febae2org.highwire.dtl.DTLVardef@9f5ff1org.highwire.dtl.DTLVardef@153ea69org.highwire.dtl.DTLVardef@42b1ed_HPS_FORMAT_FIGEXP M_FIG C_FIG Injurious stimuli can trigger endothelial cells (EC) to undergo endothelial-to-mesenchymal transition (EndMT) that contributes to arterial remodeling and disease. EndMT is regulated in a biphasic manner by alcohol with low-to-moderate levels (1-3 drink equivalent) suppressing EndMT and attenuating vascular remodeling, whereas higher level/binge exposure (7 drink equivalent) promotes these processes. Graphic created using Biorender.

cell biology↗

bioRxiv2023

N-Glycans on the extracellular domain of the Notch1 receptor control Jagged-1 induced Notch signalling and myogenic differentiation of S100β resident vascular stem cells

Notch signalling, critical for development and postnatal homeostasis of the vascular system, is highly regulated by several mechanisms including glycosylation. While the importance of O-linked glycosylation is widely accepted, the structure and function of N-glycans has yet to be defined. Here, we take advantage of lectin binding assays in combination with pharmacological, molecular, and site-directed mutagenetic approaches to study N-glycosylation of the Notch1 receptor. We find that several key oligosaccharides containing bisecting or core fucosylated structures decorate the receptor, control expression and receptor trafficking, and dictate Jagged-1 activation of Notch target genes and myogenic differentiation of multipotent S100{beta} vascular stem cells. N-glycans at asparagine (N) 1241 and 1587 protect the receptor from accelerated degradation, while the oligosaccharide at N888 directly affects signal transduction. Conversely, N-linked glycans at N959, N1179, N1489 do not impact canonical signalling but inhibit differentiation. Our work highlights a novel functional role for N-glycans in controlling Notch1 signalling and differentiation of vascular stem cells. TeaserA sweet development in Notch regulation of vascular smooth muscle cell differentiation

cell biology↗

bioRxiv2022

A short-term decellularisation technique for porcine carotid arteries that conveys a structural stimulus to cells

In many cases, treatment for stenotic atherosclerotic lesions requires the use of bypass grafts to divert blood flow around the diseased vessel sections. Autologous vessels are considered the "gold standard" for bypass conduits; however, the shortage of healthy autologous vessels has resulted in an increasing focus on optimising synthetic, biological and/or tissue engineered vascular bypass grafts. While many of the previously published methods have been shown to fall short of producing an ideal TEVG, this report presents a decellularisation process that produces an acellular vascular graft that is efficient, cost effective, and could be readily automated. The resulting graft can be used "off the shelf", has preserved arterial structure and mechanical properties, and conforms to decellularisation criteria regarding the sufficient removal of cellular and genetic components. Additionally, the graft does not require any priming, supports molecular transport, can withstand supraphysiological pressures, and can support cell attachment and growth under physiological strain conditions whilst providing structural cues for cell adhesion and growth. Impact statementVascular disease remains the leading cause of mortality worldwide. In the absence of suitable autologous vessels, there currently exists a clear clinical need for off the shelf vascular grafts that can successfully bypass diseased arteries. This paper outlines a short-term method for obtaining such a graft. The technique used involves decellularising porcine carotid arteries whilst preserving arterial structure and mechanical properties and is compliant with the international standard for implantable vascular prostheses: EN ISO 7198:2017. Additionally, this protocol is cost and time effective, and produces reproducible "ready to use" acellular grafts that support molecular transport, can withstand supraphysiological pressures, and can support cell attachment and growth with controlled structural cues under physiological strain conditions.

bioengineering↗

bioRxiv2020

Native Extracellular Matrix Orientation Determines Multipotent Vascular Stem Cell Proliferation in Response to Cyclic Uniaxial Tensile Strain and Simulated Stent Indentation

Cardiovascular disease is the leading cause of death worldwide, with multipotent vascular stem cells (MVSC) implicated in contributing to diseased vessels. MVSC are mechanosensitive cells which align perpendicular to cyclic uniaxial tensile strain. Within the blood vessel wall, collagen fibers constrain cells so that they are forced to align circumferentially, in the primary direction of tensile strain. In these experiments, MVSC were seeded onto the medial layer of decellularized porcine carotid arteries, then exposed to 10%, 1 Hz cyclic tensile strain for 10 days with the collagen fiber direction either parallel or perpendicular to the direction of strain. Cells aligned with the direction of the collagen fibers regardless of the orientation to strain. Cells aligned with the direction of strain showed an increased number of proliferative Ki67 positive cells, while those strained perpendicular to the direction of cell alignment showed no change in cell proliferation. A bioreactor system was designed to simulate the indentation of a single, wire stent strut. After 10 days of cyclic loading to 10% strain, MVSC showed regions of densely packed, highly proliferative cells. Therefore, MVSC may play a significant role in in-stent restenosis, and this proliferative response could potentially be controlled by controlling MVSC orientation relative to applied strain.

bioengineering↗

bioRxiv2020

The calcium binding protein S100β marks Hedgehog-responsive perivascular stem cells that contribute to intimal thickening following iatrogenic flow restriction

A hallmark of subclinical atherosclerosis is the accumulation of vascular smooth muscle cell (SMC)-like cells leading to intimal thickening. While medial SMCs contribute, the participation of hedgehog responsive resident vascular stem cells (vSCs) to lesion formation remains unclear. Using transgenic eGFP mice and genetic lineage tracing of S100{beta} vSCs in vivo, we identified S100{beta}/Sca1 cells derived from a S100{beta} non-SMC parent population within lesions that co-localise with smooth muscle -actin (SMA) cells following iatrogenic flow restriction, an effect attenuated following hedgehog inhibition with the smoothened inhibitor, cyclopamine. In vitro, S100{beta}/Sca1 cells isolated from atheroprone regions of the mouse aorta expressed hedgehog signalling components, acquired the di-methylation of histone 3 lysine 4 (H3K4me2) stable SMC epigenetic mark at the Myh11 locus and underwent myogenic differentiation in response to recombinant sonic hedgehog (SHh). Both S100{beta} and PTCH1 cells were present in human vessels while S100{beta} cells were enriched in arteriosclerotic lesions. Recombinant SHh promoted myogenic differentiation of human induced pluripotent stem cell-derived S100{beta} neuroectoderm progenitors In vitro. We conclude that hedgehog responsive S100{beta} vSCs contribute to lesion formation and support targeting hedgehog signalling to treat subclinical arteriosclerosis.

cell biology↗

bioRxiv2020

Disease-relevant single cell photonic signatures identify S100β+ stem cells and their myogenic progeny in vascular lesions

A hallmark of subclinical atherosclerosis is the accumulation of vascular smooth muscle cell (SMC)-like cells leading to intimal thickening and lesion formation. While medial SMCs contribute to vascular lesions, the involvement of resident vascular stem cells (vSCs) remains unclear. We evaluated single cell photonics as a discriminator of cell phenotype in vitro before the presence of vSC within vascular lesions was assessed ex vivo using supervised machine learning and further validated using lineage tracing analysis. Using a novel lab-on-a-Disk (Load) platform, label-free single cell photonic emissions from normal and injured vessels ex vivo were interrogated and compared to freshly isolated aortic SMCs, cultured Movas SMCs, macrophages, B-cells, S100{beta}+ mVSc, bone marrow derived mesenchymal stem cells (MSC) and their respective myogenic progeny across five broadband light wavelengths ({lambda}465 - {lambda}670 {+/-} 20 nm). We found that profiles were of sufficient coverage, specificity, and quality to clearly distinguish medial SMCs from different vascular beds (carotid vs aorta), discriminate normal carotid medial SMCs from lesional SMC-like cells ex vivo following flow restriction, and identify SMC differentiation of a series of multipotent stem cells following treatment with transforming growth factor beta 1 (TGF-{beta}1), the Notch ligand Jaggedl, and Sonic Hedgehog using multivariate analysis, in part, due to photonic emissions from enhanced collagen III and elastin expression. Supervised machine learning supported genetic lineage tracing analysis of S100{beta}+ vSCs and identified the presence of S100{beta}+ vSC-derived myogenic progeny within vascular lesions. We conclude disease-relevant photonic signatures may have predictive value for vascular disease.

cell biology↗