Biology subjects

Paloschi, V.

Publications and source records attributed to Paloschi, V..

5 recordsLinked to original sources

bioRxiv2026

Deep Visual Proteomics links vascular smooth muscle cell phenotypes to atherosclerotic plaque stability

Vascular smooth muscle cells (VSMCs) drive atherosclerosis through phenotypic switching, yet their spatial organization and protein signatures within plaques remain poorly characterized. Here, we applied Deep Visual Proteomics (DVP) to dissect more than 500 VSMC neighborhoods across 24 human carotid plaques and profile VSMC plasticity in disease. To functionally interpret these tissue proteomes, we built a reference atlas of primary VSMCs driven toward five phenotypes by TGF-{beta}, PDGF-BB, osteogenic stimuli, IL-1{beta}, or cholesterol, quantifying over 10,000 proteins. We integrated tissue and reference proteomes with a deep-learning framework that assigns functional phenotypes to each neighborhood. This revealed spatially distinct phenotype distributions and a shift toward dedifferentiated states in unstable plaques. Knockdown of four candidates (TNC, TNFAIP2, AEBP1, PLK1) validated operational roles during phenotypic switching. Our approach functionally annotates spatial proteomes and links VSMC plasticity to plaque instability in carotid artery disease.

systems biology↗

bioRxiv2024

Topological Excitations govern Ordering Kinetics in Endothelial Cell Layers

Many physiological processes, such as the shear flow alignment of endothelial cells in the vasculature, depend on the transition of cell layers between disordered and ordered phases. Here, we demonstrate that such a transition is driven by the non-monotonic evolution of nematic topological defects and the emergence of topological strings that bind the defects together, unveiling an intermediate phase of ordering kinetics in biological matter. We used time-resolved large-scale imaging and physical modeling to resolve the nature of the non-monotonic decrease in the number of defect pairs. The interaction of the intrinsic cell layer activity and the alignment field determines the occurrence of defect domains, which defines the nature of the transition. Defect pair annihilation is mediated by topological strings spanning multicellular scales within the cell layer. We propose that these long-range interactions in the intermediate ordering phase have significant implications for a wide range of biological phenomena in morphogenesis, tissue remodeling, and disease progression.

biophysics↗

bioRxiv2024

Endothelial cannabinoid CB1 receptor deficiency reduces arterial inflammation and lipid uptake in response to atheroprone shear stress

BackgroundPeripherally restricted cannabinoid CB1 receptor antagonists without central side effects hold promise for treating metabolic disorders including diabetes and obesity. In atherosclerosis, the specific effects of peripheral CB1 signaling in vascular endothelial cells (ECs) remain incompletely understood. Methods and resultsEndothelial expression of the CB1 encoding gene CNR1 was detectable in human plaque single-cell RNA sequencing data. In situ hybridization of Cnr1 in murine aortas revealed a significantly increased endothelial expression within atheroprone compared to atheroresistant regions. In vitro, CNR1 was upregulated by oscillatory shear stress (OSS) in human aortic endothelial cells (HAoECs). Endothelial CB1 deficiency (Cnr1EC-KO) in female mice on atherogenic background resulted in pronounced endothelial phenotypic changes, with reduced vascular inflammation and permeability. This resulted in attenuated plaque development with reduced lipid content in female mice, while reduced white and brown adipose tissue mass and liver steatosis were observed in both males and females. Ex vivo imaging of carotid arteries via two-photon microscopy revealed less labeled low density lipoprotein (Dil-LDL) uptake in Cnr1EC-KO. This was accompanied by a significant reduction of aortic endothelial caveolin-1 (CAV1) expression, a key structural protein involved in lipid transcytosis, in female Cnr1EC-KO mice. In vitro, pharmacological blocking with CB1 antagonist AM281 reproduced the inhibition of CAV1 expression and Dil-LDL uptake in response to atheroprone OSS in HAoECs, which was dependent on cAMP-mediated PKA activation. Conversely, the CB1 agonist ACEA increased Dil-LDL uptake and CAV1 expression in HAoECs. Finally, treatment of atherosclerotic mice with the peripheral CB1 antagonist JD-5037 reduced plaque progression, CAV1 and endothelial adhesion molecule expression in female mice. ConclusionsThese results confirm an essential role of endothelial CB1 to the pathogenesis of atherosclerosis. Peripheral CB1 antagonists may hold promise as an effective therapeutic strategy for treating atherosclerosis and related metabolic disorders. NOVELTY AND SIGNIFICANCEWhat is known? O_LIEnhanced endocannabinoid-cannabinoid CB1 receptor signaling has been implicated in metabolic disorders, atherosclerosis, and hypertension, but the cell-specific role of endothelial CB1 in atherosclerosis is not well understood. C_LIO_LIGlobal CB1 antagonists improve metabolic function and inhibit atherosclerotic plaque development in mouse models, but have failed in the clinic due to centrally mediated psychiatric side effects. C_LI What is new? O_LIBased on human single-cell RNA sequencing data, CB1 is expressed in human plaque ECs. C_LIO_LIUsing transgenic mouse models and human primary aortic endothelial cells, we provide evidence for a key role of CB1 in endothelial shear stress response, inflammatory gene expression, and LDL uptake. C_LIO_LIThe underlying signaling pathway of CB1-induced endothelial LDL uptake involves a cAMP-PKA-dependent regulation of caveolin 1 (CAV1) expression, a structural protein of the shear stress sensitive signaling domains of the plasma membrane. C_LIO_LIBy limiting endothelial CAV1 and VCAM1 expression, peripherally restricted CB1 antagonists confer atheroprotection in mice. C_LI Our findings reveal that endothelial CB1 expression is induced by atheroprone shear stress responses and contributes to impaired vascular barrier function, inflammation, and lipid uptake, thereby promoting atherosclerotic lesion formation and progression. By elucidating the transcriptomic pathways regulated by endothelial CB1 and its broad influence on lipid uptake and metabolism in arteries, liver, and brown and white adipose tissue, our study provides insights into novel pathways and potential interventions for the treatment of atherosclerosis and metabolic disorders. The use of peripherally restricted CB1 antagonists that specifically target vascular inflammation and tissue lipid storage could be a complementary and safe therapeutic avenue to treat cardiovascular and metabolic disease comorbidities without altering CB1 signaling in the brain.

immunology↗

bioRxiv2022

Utilization of an Artery-on-a-chip to unravel novel regulators and therapeutic targets in vascular diseases

IntroductionOrgans-on-chips represent novel in vitro models that have the capacity to emulate aspects of human physiology and pathophysiology by incorporating features like tissue-multicellularity and exposure to organ-relevant physical environment. We developed an artery-on-a-chip with the objective to recapitulate the structure of the arterial wall composed of intimal and medial layers and the relevant hemodynamic forces that affect luminal cells. ResultsBy comparing arteries-on-chips exposed either to in vivo-like shear stress values or kept in static conditions, we identified a panel of novel genes modulated by shear stress. We next measured the expression pattern of shear stress-modulated genes in areas of the vascular tree affected by atherosclerotic plaques and aortic aneurysms, where disease development and progression are induced by alterations of shear stress. We obtained biopsies from patients affected by carotid artery disease (CAD), comprising the atherosclerotic plaque (diseased artery) and the adjacent region (non-diseased artery). From patients with abdominal aortic aneurysms (AAA), we obtained the aneurysmal portion (diseased aorta) and non-dilated adjacent segment (non-diseased aorta). Genes modulated by shear stress followed the same expression pattern in non-diseased segments of human vessels and were expressed by endothelial and smooth muscle cells as evidenced by immunofluorescence analysis and single cell RNA sequencing. Using mice and porcine models of vascular CAD and AAA, we confirmed that shear stress mediated targets are important in discriminating diseased and non-diseased vessel portions in vivo. Furthermore, we showed that our artery-on-a-chip can serve as a platform for drug-testing. We were able to reproduce the effects of a therapeutic agent previously used in AAA animal models in artery-on-a-chip systems and extend our understanding of its therapeutic effect through a multicellular structure. ConclusionsOur novel in vitro model is capable of mimicking important physiological aspects of human arteries, such as the response to shear stress, and can further shed light on the mechanism of action of potential therapeutics before they enter the clinical stage. TeaserThe artery-on-a-chip is a novel in vitro platform that enables the mimicry of human arteries and can be used to gain insights into the development and therapeutic targeting of vascular diseases.

cell biology↗

bioRxiv2022

The circular RNA Ataxia-telangiectasia mutated (cATM) regulates oxidative stress in smooth muscle cells in expanding abdominal aortic aneurysms

An abdominal aortic aneurysm (AAA) is a pathological widening of the aortic wall characterized by loss of smooth muscle cells (SMCs), extracellular matrix degradation, and local inflammation. This condition is often asymptomatic until rupture occurs, leading to high morbidity and mortality rates. Diagnosis is often accidental, and for now, the only available treatment option remains surgical intervention. Circular RNAs (circRNAs) are RNA loops that originated from backsplicing, which have received increasing attention as a novel class of functional non-coding RNAs contributing to cardiovascular physiology and disease. Their high structural stability, combined with a remarkable enrichment in body fluids, make circRNAs promising disease biomarkers. We aimed to investigate the contribution of circRNAs to AAA pathogenesis and their potential application as biomarkers for AAA diagnosis. Combined circRNA array and quantitative real-time PCR analysis revealed the presence of differentially expressed circular transcripts stemming from AAA-relevant gene loci. Among these, the circRNA to the Ataxia-telangiectasia mutated gene (cATM) was upregulated in human AAA tissue specimens, in AAA patient-derived SMCs, and serum samples collected from aneurysm patients. In control primary aortic SMCs, cATM increased upon angiotensin II stimulation, while its silencing triggered apoptosis. Furthermore, doxorubicin could induce cATM expression, supporting a link with acute stress response in SMCs. Constitutively higher cATM expressing AAA patient-derived SMCs were less vulnerable to oxidative stress-induced cell death and survival pathways enriched when compared to control SMCs. Taken together, this data supports the role of cATM in adapting SMCs to oxidative stress in the vascular AAA micromilieu. This molecular signature provides an additional parameter to be included in procedures for AAA screening in combination with already established practices.

molecular biology↗