Biology subjects

Cagnone, G.

Publications and source records attributed to Cagnone, G..

9 recordsLinked to original sources

bioRxiv2026

SOX9 regulates endothelial tip cell specification to promote cerebral and neuroretinal vascularization

BackgroundTissue vascularization relies on the organotypic specification of endothelial tip cells to interpret local cues and guide angiogenic sprouts into specific tissue compartments. However, the molecular regulators controlling brain and retinal endothelial tip cell identity remain poorly understood. MethodsEndothelial-specific Sox9 loss-of-function mouse was combined with single-cell, spatial, and bulk RNA sequencing analyses of developing mouse brain and retinal vasculature, as well as experimental ischemic stroke. Transcriptomic findings were validated using in situ hybridization, immunofluorescence, and functional angiogenesis assays. ResultsTranscription factor activity analysis of single-cell RNA-sequencing datasets identified SOX9 as a candidate regulator selectively enriched in developing brain and retinal endothelial tip cells. Endothelial-specific deletion of Sox9 impaired brain and neuroretina vascularization and disrupted the tip cell transcriptomic program, resulting in reduced sprouting angiogenesis and matrix-remodeling pathways. Conversely, SOX9 overexpression in HUVECs promoted neuro-tip-like signatures and enhanced endothelial invasion and sprouting. Following ischemic stroke, single-cell and spatial transcriptomic analyses identified a transient angiogenic endothelial population within the ischemic area. However, these cells failed to express Sox9 and lacked key developmental brain tip cell features. ConclusionsSOX9 is a key regulator of endothelial tip cell identity and neuronal angiogenesis. These findings reveal fundamental differences between developmental and injury-induced vascular responses and identify SOX9 as a potential therapeutic target to promote functional vascular regeneration.

developmental biology↗

bioRxiv2026

Developmental senescence orchestrates hyaloid vessel regression in the postnatal eye

The mammalian eye develops in concert with coordinated growth and remodeling of three vascular networks: the hyaloid vasculature, the choroid and retinal plexus. While retinal and choroidal systems support visual function in the mature eye, the hyaloid network plays a vital yet temporary role supporting the developing lens and inner retina. Regression of the hyaloid network is essential for optical clarity, yet the mechanisms guiding the process remain incompletely understood. Using single-cell RNA sequencing, we show that postnatal mouse hyaloid cells are broadly senescent. Hyaloid vascular smooth muscle, endothelial and immune cells display cell-cycle arrest marked by Cdkn1a with the expression of SASP factors. Genetic ablation of Cdkn1a impedes normal hyaloid regression, demonstrating that developmental senescence is essential for vascular remodeling and functions alongside apoptosis and macrophage-mediated clearance. These findings identify an unrecognized senescence-driven mechanism orchestrating hyaloid involution during ocular development, broadening the understanding of vascular remodeling in the eye.

cell biology↗

bioRxiv2025

Loss of endothelial ALK1 signaling induces the emergence of a KIT+ angiogenic endothelial cluster driving brain arteriovenous malformations

BackgroundHereditary Hemorrhagic Telangiectasia type 2 (HHT2) is a genetic disorder caused by mutations in the ALK1 (ACVRL1) gene, encoding a receptor for Bone Morphogenetic Proteins 9 and 10 (BMP9/BMP10). HHT2 patients frequently develop brain arteriovenous malformations (bAVMs), which are abnormal connections between arteries and veins. Currently, surgical resection is the only treatment, associated with significant risks and complications. Despite evidence suggesting endothelial cell (EC) heterogeneity in bAVMs, it remains poorly characterized, limiting our ability to identify new therapeutic avenues. MethodsWe employed endothelial cell-specific and inducible Alk1 knockout mice (Alk1iECKO) with tamoxifen-induced deletion at postnatal day 6 (P6). We separately analyzed the P8 perineural (PNVP) and intraneural (INVP) vascular plexuses, which differ in vessel composition and flow dynamics. Single-cell RNA sequencing (scRNAseq) was performed to characterize EC heterogeneity and identify transcriptomic changes in both vascular plexuses of mutant versus wild type mice. ResultsLoss of endothelial ALK1 signaling triggered bAVM formation predominantly in the PNVP vascular network. scRNAseq revealed that Alk1 deletion promoted brain capillaries differentiation into angiogenic-1 ECs, whereas it drove PNVP venules EC proliferation and the emergence of the unique angiogenic-2 cluster. The latter shares transcriptomic features with human AVM ECs, including angiogenic tip cell markers and a strong glycolytic signature. Among its defining markers, Kit emerged as a direct downstream target of BMP9-ALK1 signaling. Pharmacological KIT inhibition using Masitinib, Imatinib, or KIT-blocking antibodies prevented bAVM formation in Alk1iECKO mice. ConclusionOur study uncovers a previously unrecognized EC population, the angiogenic-2 cluster, as a key contributor to bAVM development. We identify Kit as a central regulator of this cluster, establishing it as a promising therapeutic target for preventing bAVMs in HHT2. Clinical PerspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIUsing endothelial-specific Alk1 knockout mouse models and single-cell transcriptomics, we identified a novel angiogenic endothelial cell population as a key driver of brain AVM formation. C_LIO_LIThis angiogenic EC cluster shares molecular features with human bAVM cells, including high expression of KIT, which we identified as a new direct transcriptional target of BMP9-ALK1 signaling. C_LIO_LIPharmacological inhibition of KIT using small molecules or blocking antibodies effectively prevents AVM formation in vivo, establishing KIT as a promising therapeutic target. C_LI What are the clinical implications?O_LIOur findings support the therapeutic potential of targeting KIT with FDA-approved drugs such as Imatinib to treat HHT2-associated brain AVMs, offering a non-invasive alternative to surgical intervention. C_LIO_LICharacterizing AVM-specific endothelial subtypes may enable the development of targeted and personalized therapies, improving patient outcomes and minimizing treatment-associated risks in HHT. C_LI

cell biology↗

bioRxiv2025

Time-dependent chromatin maturation during 3D spheroid culture improves preclinical modeling of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the deadliest cancer worldwide. Therapeutic progress stagnate, highlighting the complexity to replicate NSCLC in preclinical models. Drug discovery studies rely mostly on cancer cells in two-dimension (2D), which poorly predict drug efficacy in patients. There is a growing interest in three-dimensional (3D) preclinical models, such as 3D spheroids, to better model tumor phenotype and improve therapeutic prediction. However, a comprehensive view of 3D culture methods impact on transcriptomes, epigenomes and pharmacological responses and their correlations to NSCLC tumors is still missing. Here, we demonstrate that NSCLC spheroids undergo time-dependent transcriptomic and epigenomic changes, which peak after 3 weeks of culture. While DNA methylome remained stable, chromatin methylation and acetylation marks gained features of advanced NSCLC in a time-dependent manner. Single-cell transcriptomic profiling of spheroids demonstrated that time of 3D culture improved the correlation to NSCLC tumors. Moreover, long-term culture of 3D spheroids increased drug screening predictability, by showing resistance to drugs that failed in NSCLC patients (such as HDAC inhibitors) while demonstrating novel pharmacological vulnerabilities and synergistic interactions (such as combination of PRMT and HDAC inhibitors). Strikingly, reverting 3D spheroids back to 2D culture rapidly reversed transcriptomic, epigenetic and pharmacological signatures acquired after 3 weeks of 3D culture, highlighting the critical impact of cell culture conditions on NSCLC phenotype. Collectively, our findings demonstrate that implementing a time-dependent maturation process into 3D spheroid culture induces chromatin and transcriptomic changes that enhance NSCLC preclinical modeling.

cancer biology↗

bioRxiv2024

Corticosteroids prevent pathological angiogenesis yet compromise reparative vascular remodeling in the retina

Tissue inflammation is often broadly associated with cellular damage, yet sterile inflammation also plays critical roles in beneficial tissue remodeling. In the central nervous system (CNS), this is observed through a predominantly innate immune response in retinal vascular diseases such as age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity. Here we set out to elucidate the dynamics of the immune response during progression and regression of pathological neovascularization in retinopathy. In a mouse model of oxygen-induced retinopathy, we report that broad spectrum corticosteroid drugs such as dexamethasone suppress initial formation of pathological pre-retinal neovascularization in early stages of disease, yet blunt successive waves of reparative inflammation and hence prevent beneficial vascular remodeling. Using genetic depletion of distinct components of the innate immune response, we demonstrate that CX3C chemokine receptor 1 (CX3CR1)-expressing microglia contribute to angiogenesis. Conversely, myeloid cells expressing Lyz-M (lysozyme 2) are recruited to sites of damaged blood vessels and pathological neovascularization where they partake in a reparative process that ultimately restores circulatory homeostasis to the retina. Hence, the Janus-faced properties of anti-inflammatory drugs should be considered when treating retinal vascular disease and particularly in stages associated with persistent neovascularization.

immunology↗

bioRxiv2023

Metabolic Reprogramming of the Neovascular Niche Promotes Regenerative Angiogenesis in Proliferative Retinopathy

Healthy blood vessels supply neurons to preserve metabolic function. In blinding ischemic proliferative retinopathies (PRs), pathological neovascular tufts often emerge in lieu of needed physiological neuroretina revascularization. We show that metabolic shifts in the neurovascular niche define this angiogenic dichotomy between healthy and diseased blood vessel growth. Fatty acid oxidation (FAO) metabolites accumulated in human and murine retinopathy samples. Neovascular tufts with a distinct single-cell transcriptional signature highly expressed FAO enzymes. The deletion of Sirt3, an FAO regulator, shifted the neurovascular niche metabolism from FAO to glycolysis and suppressed tuft formation. This metabolic transition increased Vegf expression in astrocytes and reprogrammed pathological EC to a physiological phenotype, hastening vascular regeneration of the ischemic retina. Our findings identify SIRT3 as a metabolic switch in the neurovascular niche, offering a new therapeutic target for optimizing ischemic tissue revascularization. HighlightsO_LIPathological EC favor FAO over glycolysis. C_LIO_LIUnique signature for pathological EC found in proliferative retinopathy model. C_LIO_LISirt3 deletion shifts astrocytes and EC metabolism from FAO to glycolysis. C_LIO_LIMetabolic reprogramming of the vascular niche enhances physiological revascularization. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=83 SRC="FIGDIR/small/566898v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@70020eorg.highwire.dtl.DTLVardef@19719acorg.highwire.dtl.DTLVardef@1168ddeorg.highwire.dtl.DTLVardef@1bc25e0_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2022

Nuclear Location Bias of HCAR1 Drives Cancer Malignancy through Numerous Routes

The involvement of G-Protein-Coupled Receptors (GPCR) location bias in diverse cellular functions and their misregulation in pathology is an underexplored territory. HCAR1, a GPCR for lactate is linked to cancer progression, mainly due to Warburg effect, but its mechanism of action remains elusive. Here, we show HCAR1 has a nuclear localization, capable of signaling intranuclearly to induce nuclear-ERK and AKT phosphorylation concomitant with higher cancer cell proliferation and survival. We determine its nuclear interactome, proving its involvement in protein-translation and DNA-damage repair. Nuclear HCAR1 (N-HCAR1) directly interacts with chromatin/DNA promoting expression of genes involved in cellular migration. Notably, we show N-HCAR1 particularly regulates a broader transcriptomic signature than its PM counterpart, emphasizing on the facts that functional output of N-HCAR1 is larger than PM localized HCAR1. Our study presents several unprecedented processes by which a GPCR through location-biased activity regulate various cellular functions and how cancer cells exploit these.

cell biology↗

bioRxiv2020

Leveraging complex interactions between signaling pathways involved in liver development to robustly improve the maturity and yield of pluripotent stem cell-derived hepatocytes

Pluripotent stem cell (PSC)-derived hepatocyte-like cells (HLC) have shown great potential as an alternative to primary human hepatocytes (PHH) for in vitro modeling. Several differentiation protocols have been described to direct PSC towards the hepatic fate, although the resulting HLC have shown more a fetal than adult phenotype. Here, by leveraging recent knowledge of the signaling pathways involved in liver development, we describe a robust, scalable protocol that allows to consistently generate high-quality HLC from both ESC and iPSC. Such HLC are comparable to adult PHH in terms of key mature liver functions and proved suitable to assess drug hepatotoxicity, as a proof of concept of their potential as a physiologically representative alternative for in vitro modeling.

developmental biology↗

bioRxiv2018

Metformin Intervention Prevents Cardiac Dysfunction in a Murine Model of Adult Congenital Heart Disease

Congenital heart disease (CHD) is the most frequent birth defect worldwide and the number of adult patients with CHD, now referred to as ACHD, is increasing. However the mechanisms whereby ACHD predisposes patients to heart dysfunction are still unclear. ACHD is strongly associated with metabolic syndrome, but how ACHD interacts with poor modern lifestyle choices and other comorbidities, such as hypertension, obesity and diabetes, is mostly unknown. Using a genetic mouse model of ACHD we showed that ACHD mice placed under metabolic stress (high fat diet) displayed decreased heart function. Comprehensive physiological, biochemical and molecular analysis showed that ACHD hearts exhibited early changes in energy metabolism that preceded cardiac dysfunction. Restoration of metabolic balance by metformin prevented the development of heart dysfunction in ACHD mice. This study reveals that early metabolic impairment reinforces heart dysfunction in ACHD predisposed individuals and diet or pharmacological interventions can be used to modulate heart function and attenuate heart failure and may be an important avenue for intervention in ACHD.

genetics↗