Biology subjects

Silvestre-Roig, C.

Publications and source records attributed to Silvestre-Roig, C..

4 recordsLinked to original sources

bioRxiv2026

The transcription factor NF-Y promotes myeloid cell survival and protects from inflammatory vascular disease

BackgroundMyeloid cells orchestrate vascular inflammation through transcriptional programs that regulate their maturation, effector function, and survival. While lineage-determining transcription factors establish myeloid identity, understanding of the transcriptional regulation of myeloid behavior in chronic inflammatory contexts remains limited. Nuclear factor-Y (NF-Y) is a trimeric CCAAT-binding transcription factor that regulates cell proliferation and differentiation. Here, we investigate the role of NF-Y in myeloid function and survival during chronic vascular inflammation. MethodsIntegrated single-cell transcriptomics of BM, blood, and atherosclerotic lesions were combined with myeloid-specific NF-YA inactivation to define NF-Y-dependent transcriptional states. Functional consequences were assessed in mice with myeloid-specific Nfya deletion on a hypercholesterolemic Apoe-/- background using models of diet-induced advanced atherosclerosis and endoluminal femoral injury. Myeloid cell recruitment, survival, apoptosis, and proliferation were further examined in models of thioglycolate-induced peritonitis. ResultsNF-Y subunit transcripts were detected across myeloid compartments, with Nfya enriched in proliferative macrophages and immature neutrophils. In mouse atherosclerotic lesions, low Nfya expression was associated with lipid-handling and phagocytic macrophage signatures and a pro-inflammatory neutrophil phenotype. Myeloid Nfya deficiency was further associated with reduced circulating neutrophil counts, increased macrophage and neutrophil apoptosis during acute inflammation, expanded necrotic cores, larger unstable atherosclerotic lesions, and aggravated atherosclerosis and injury-induced neointimal thickening. ConclusionOur data identify NF-Y as a transcriptional safeguard of myeloid cell survival during inflammatory stress, thereby shaping disease progression and outcomes in vascular disease.

immunology↗

bioRxiv2025

The nuclear receptor NR4A1 serves as a neutrophil-intrinsic regulator mitigating stroke severity

Ischemic stroke is accompanied by recruitment and activation of immune cells which play an important role in the progression of the brain damage. The nuclear receptor NR4A1 emerged as a key regulator within the inflammatory response of several immune diseases by regulating immune cell activation. In this study, we investigated the role of NR4A1 in the activation and recruitment of brain resident and peripheral immune cells after cerebral ischemia. Here, we show that NR4A1 mediates an anti-inflammatory and damage-limiting effect after stroke. This effect is largely mediated by neutrophil recruitment and importantly, NR4A1 activation with its ligand Cytosporone B improves functional outcome and reduces brain damage. Modulation of NR4A1 is therefore a promising therapeutic target for the treatment of the nuclear receptor NR4A1 in the activation and recruitment of peripheral and brain resident immune cells after cerebral ischemia and its consequences for stroke outcome. We demonstrate that NR4A1 ablation augments neutrophil activation and CNS recruitment within days after stroke thereby increasing infarct size, CNS inflammation, neuronal damage and deteriorating functional outcome. This effect is mediated via modulation of cell-intrinsic neutrophil function and maturation as illustrated by neutrophil-specific NR4A1 ablation and mixed bone-marrow chimera experiments. Notably, the NR4A1 agonist Cytosporone B reduced CNS neutrophil infiltration, infarct size and functional outcome after stroke in a bicentric preclinical stroke trial, demonstrating that NR4A1-mediated control of neutrophil reactivity is amenable to pharmacological modulation. In humans, NR4A1 expressing neutrophils are present in the peripheral blood of stroke patients and neutrophil NR4A1 expression correlates with improved long-term outcome after 3 months. Furthermore, NR4A1 expression in brain parenchyma neutrophils is negatively correlated with neuronal cell loss, illustrating a role of NR4A1 in regulating neutrophil mediated neuronal cell death in human stroke. Together our data reveal the nuclear factor NR4A1 as a brake of intrinsic neutrophil activity controlling neutrophil-mediated brain inflammation and neurotoxicity in stroke which may serve as a novel therapeutic target to limit inflammation-associated augmentation of ischemic damage after stroke.

neuroscience↗

bioRxiv2025

CCR2+ neutrophils exhibit a proinflammatory phenotype and promote plaque destabilization

BackgroundAtherosclerotic plaque destabilization is promoted by inflammatory cell recruitment, tissue cell death and mechanical weakening. Neutrophils are key instigators of vascular tissue injury and perpetuation of inflammation, and targeting their actions is a viable therapeutic opportunity. We here identify a distinct subset of activated neutrophils within atherosclerotic lesions that express the chemokine receptor CCR2, which directs their migration toward areas enriched with smooth muscle cells (SMCs) and contributes to plaque instability. MethodsFlow cytometry and single cell transcriptomic analysis of CCR2+ neutrophils within murine and human atherosclerotic plaques. Tracking of CCR2+ neutrophil in hypercholesterolemic Ldlr-/- mice and in mice reconstituted with Ccr2GFP/- bone marrow. In vivo reactive oxygen species (ROS) and neutrophil extracellular trap (NET) analysis in lipopolysaccharide-induced peritonitis. In vitro migration assays of neutrophils deficient for or treated with specific antagonist against chemokine receptors. In vivo neutrophil recruitment and atherosclerotic plaque destabilization analysis upon CCR2 and CCL2 blockade in a model of advanced atherosclerosis in Apoe-/- mice. ResultsCCR2+ neutrophils preferentially populate mouse and human atherosclerotic lesions and displayed a proinflammatory phenotype with enhanced capacity for ROS production and NET release. Genetic deletion or pharmacologic inhibition of CCR2 significantly reduces neutrophil migration and infiltration to the atherosclerotic lesion, reducing their presence in SMC-rich areas. Consistently, neutralization of the CCR2 ligand CCL2 decreased lesional neutrophil numbers and preserved fibrous cap integrity by increasing SMC content and decreasing overall plaque instability. ConclusionsOur data suggest that a subset of CCR2-expressing neutrophils senses SMC-derived CCR2 ligands to infiltrate and destabilize atherosclerotic lesions. These results support the existence of neutrophil functional heterogeneity within the atherosclerotic lesions contributing to alterations of lesion stability. Specific targeting thereof may improve plaque stability without impacting host defense.

immunology↗

bioRxiv2023

Infection-induced vascular inflammation in COVID-19 links focal microglial dysfunction with neuropathologies through IL-1/IL-6-related systemic inflammatory states

COVID-19 is associated with diverse neurological abnormalities, which predict poor outcome in patients. However, the mechanisms whereby infection-induced inflammation could affect complex neuropathologies in COVID-19 are unclear. We hypothesized that microglia, the resident immune cells of brain, are centrally involved in this process. To study this, we developed an autopsy platform allowing the integration of molecular anatomy-, protein- and mRNA data sets in post-mortem mirror blocks of brain and peripheral organ samples from COVID-19 cases. Nanoscale microscopy, single-cell RNA sequencing and analysis of inflammatory and metabolic signatures revealed distinct mechanisms of microglial dysfunction associated with cerebral SARS-CoV-2 infection. We observed focal loss of microglial P2Y12R at sites of virus-associated vascular inflammation together with dysregulated microglia-vascular-astrocyte interactions, Cx3Cr1-fractalkine axis deficits and mitochondrial failure in severely affected medullary autonomic nuclei and other brain areas. Microglial dysfunction occurs at sites of excessive synapse- and myelin phagocytosis and loss of glutamatergic terminals. While central and systemic viral load is strongly linked in individual patients, the regionally heterogenous microglial reactivity in the brain correlated with the extent of central and systemic inflammation related to IL-1 / IL-6 via virus-sensing pattern recognition receptors (PRRs) and inflammasome activation pathways. Thus, SARS-CoV-2-induced central and systemic inflammation might lead to a primarily glio-vascular failure in the brain, which could be a common contributor to diverse COVID-19-related neuropathologies.

immunology↗